19,671 results on '"Chen Fei"'
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2. Pterocymbium R. Br ( Malvaceae , Sterculioideae ), a genus new to China
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ZHAO Mingxu, TAN Yunhong, YANG Zicheng, LI Jinhua, YAN Wende, and CHEN Fei
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pterocymbium ,malvaceae ,biogeography ,indo-burma biodiversity hotspot ,transboundary biodiversity conservation ,Biology (General) ,QH301-705.5 ,Botany ,QK1-989 - Abstract
[ Objective ] The present study reports a newly recorded giant tropical deciduous tree , Pterocym- bium macranthum Kosterm. , which has been spotted in the border regions of Sino-Lao , Mengla County , Yunnan Province , and both the species and genus are new to China. Furthermore , descriptions of the spe- cies and genus are amended , and the domestic population size and state of endangerment are evaluated. [ Methods ] Morphological and anatomical observations of specimens were conducted using a stereo- microscope , and key taxonomic characteristics were recorded with a digital camera. Aided by drones , its domestic population size was assessed , and its IUCN species threat level was evaluated by interviews and our field experiences. [ Results ] Around 1 000 individuals were recognized in an area ca. 2 000 hm 2 , and it was recommended as an IUCN vulnerable ( VU ) species. [ Conclusion ] The genus Pterocymbium R. Br. and its intragenus P . macranthum Kosterm. are new to China. The new discovery in China extends the known geographical range of P . macranthum to the northern edge of the Asian tropics and contributes to the knowledge of the flora both in China and Southeast Asia.
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- 2024
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3. Water Utilization Status and Suggestions for the Development of Green and Efficient Irrigation and Drainage Technology in the Main Rice-Producing Areas of Southwest China
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Cui Ningbo, Yin Feihu, Gong Daozhi, He Xiubin, Chen Fei, Zhao Lu, Zheng Shunsheng, Zhang Yixuan, and Wu Zongjun
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水稻, 灌排技术, 西南地区, 绿色高效, 节水 ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
The main rice-producing areas in Southwest China are facing production problems such as seasonal drought and engineering water shortage. A green and efficient irrigation and drainage technology system is key to achieving water conservation, stable yield, and high efficiency in the region, and it is of great significance to the food security of China. This study reviews the current status of water use, irrigation, and drainage in the main rice-producing areas in Southwest China, involving Yunnan, Guizhou, Sichuan, and Chongqing. It examines the basic characteristics and specific technical types of green and efficient irrigation and drainage systems in the areas, and proposes a green and efficient irrigation and drainage technology model that is composed of accurate water demand forecast of paddy fields, precision water distribution management in irrigation areas, efficient water use management in paddy fields, and efficient drainage management in paddy fields. The study found that the main rice-producing areas in Southwest China are rich in water resources but uneven in spatial and temporal distribution of water. The water-saving irrigation and drainage technologies in this region are backward and vary in the applicability of climate conditions, water resources, and topography. Therefore, we propose the following suggestions: (1) developing new technologies for the efficient and coordinated regulation of irrigation and drainage in paddy fields, (2) promoting the green and efficient irrigation and drainage technology system, (3) optimizing the water and fertilizer operation mode, (4) developing an intelligent irrigation system for paddy fields, (5) establishing a paddy field information management system, and (6) building a multi-dimensional technology promotion system, thus to achieve water conservation, pollution control, emission reduction, yield increase, and quality improvement in the main rice-producing areas of Southwest China.
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- 2024
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4. Prospects of Digital Medicine in Postoperative Pain Management in Children
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CHEN Fei, ZHANG Yuguan, and ZHU Bo
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digital medical treatment ,clinical anesthesia ,postoperative pain in children ,pain treatment ,Medicine - Abstract
In recent years, with the gradual and extensive application of digital medical treatment in the field of medica anesthesia, its role in the postoperative pain management of children has attracted increasing attention. It provides new ideas for the preoperative prediction, postoperative monitoring and evaluation, and treatment management of postoperative pain in children, as well as a new scheme for anesthesiologists to formulate the best postoperative pain management strategy for children. This article reviews digital medical treatment and its application in clinical anesthesia, and reviews the application prospects of this therapy in postoperative pain in children, in order to deepen clinicians' knowledge.
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- 2024
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5. Machine learning developed a CD8+ exhausted T cells signature for predicting prognosis, immune infiltration and drug sensitivity in ovarian cancer
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Rujun Chen, Yicai Zheng, Chen Fei, Jun Ye, and He Fei
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CD8+ Tex ,Machine learning ,Ovarian cancer ,Prognostic signature ,Immunotherapy ,Medicine ,Science - Abstract
Abstract CD8+ exhausted T cells (CD8+ Tex) played a vital role in the progression and therapeutic response of cancer. However, few studies have fully clarified the characters of CD8+ Tex related genes in ovarian cancer (OC). The CD8+ Tex related prognostic signature (TRPS) was constructed with integrative machine learning procedure including 10 methods using TCGA, GSE14764, GSE26193, GSE26712, GSE63885 and GSE140082 dataset. Several immunotherapy benefits indicators, including Tumor Immune Dysfunction and Exclusion (TIDE) score, immunophenoscore (IPS), TMB score and tumor escape score, were used to explore performance of TRPS in predicting immunotherapy benefits of OC. The TRPS constructed by Enet (alpha = 0.3) method acted as an independent risk factor for OC and showed stable and powerful performance in predicting clinical outcome of patients. The C-index of the TRPS was higher than that of tumor grade, clinical stage, and many developed signatures. Low TRPS score indicated a higher level of CD8+ T cell, B cell, macrophage M1, and NK cells, representing a relative immunoactivated ecosystem in OC. OC patients with low risk score had a higher PD1&CTLA4 immunophenoscore, higher TMB score, lower TIDE score and lower tumor escape score, suggesting a better immunotherapy response. Moreover, higher TRPS score indicated a higher score of cancer-related hallmarks, including angiogenesis, EMT, hypoxia, glycolysis, and notch signaling. Vitro experiment showed that ARL6IP5 was downregulated in OC tissues and inhibited tumor cell proliferation. The current study constructed a novel TRPS for OC, which could serve as an indicator for predicting the prognosis, immune infiltration and immunotherapy benefits for OC patients.
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- 2024
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6. Reversible Snapping of Constrained Anisotropic Hydrogels Upon Light Stimulations
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Chen Fei Dai, Qing Li Zhu, Olena Khoruzhenko, Michael Thelen, Huiying Bai, Josef Breu, Miao Du, Qiang Zheng, and Zi Liang Wu
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anisotropic hydrogels ,fast actuation ,nanosheets ,snapping ,soft actuators ,Science - Abstract
Abstract Creatures, such as Venus flytrap and hummingbirds, capable of rapid predation through snap‐through transition, provide paradigms for the design of soft actuators and robots with fast actions. However, these artificial “snappers” usually need contact stimulations to trigger the flipping. Reported here is a constrained anisotropic poly(N‐isopropylacrylamide) hydrogel showing fast snapping upon light stimulation. This hydrogel is prepared by flow‐induced orientation of nanosheets (NSs) within a rectangular tube. The precursor containing gold nanoparticles is immediately exposed to UV light for photopolymerization to fix the ordered structure of NSs. Two ends of the slender gel are clamped to form a buckle with bistability nature, which snaps to the other side upon laser irradiation. Systematic experiments are conducted to investigate the influences of power intensity and irradiation angle of the laser, as well as thickness and buckle height of the gel, on the snapping behaviors. The fast snapping is further used to kick a plastic bead and control the switch state. Furthermore, synergetic or oscillated snapping of the gel with two buckles of opposite directions is realized by inclined irradiation of a laser or horizontal irradiation with two lasers, respectively. Such light‐steered snapping of hydrogels should merit designing soft robots, energy harvests, etc.
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- 2024
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7. Severity of COVID-19 reinfection among healthcare workers in a grade A tertiary hospital in Shanghai by the end of 2022
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LIU Wanwan, DENG Qiuqiong, MI Jianhua, GU Jingli, YU Ling, HUANG Zhuyi, ZHAO Jiahong, CHEN Fei, CAO Qin, and XU Qun
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covid-19 ,epidemic characteristic ,reinfection ,primary infection ,healthcare worker ,Medicine - Abstract
ObjectiveTo describe the epidemic characteristics of COVID-19 after policy adjustment from “Category B notifiable disease with category A management” to “Category B notifiable disease with category B management”, and to explore the protective effect of previous infection with SARS-CoV-2 on common symptoms of reinfection.MethodsHealthcare workers infected with SARS-CoV-2 in a grade A tertiary hospital in Shanghai were included in the study from December 4, 2022 to January 11, 2023. Data on demographic characteristics, clinical symptoms, medical history, and COVID-19 vaccination history were collected. We determined the epidemiological curve and characteristics, and then compared the difference in the severity of clinical symptoms between primary and reinfection subjects.ResultsA total of 2 704 cases were included in the study, of which 45 had reinfection, 605 (22.4%)were males, 608 (22.5%)were doctors, 1 275 (47.2%) were nurses, and 2 351 (86.9%) received ≥3 doses of COVID-19 vaccination. The average age of these healthcare workers was (34.9±9.1) years old. The number of cases with mild/moderate illness, asymptomatic infection, fever, headache, dry cough, expectoration, and chest tightness were 2 704 (100.0%), 92 (3.4%), 2 385 (88.2%), 2 066 (76.4%), 1 642 (60.7%), 1 807 (66.8%), and 439 (16.2%), respectively. Reinfection was a protective factor for fever (OR=0.161, P
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- 2024
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8. Effect of ultra-high-speed laser melting deposition process on performance of Al-Mg-Sc high-strength aluminum alloy
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WEN Pin, DONG Ziliang, WU Yu, DONG Dingyang, LUO Xing, DU Borui, XU Peixin, and CHEN Fei
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ultra-high speed laser melting deposition ,high strength aluminum alloy ,mechanical properties ,numerical simulation ,Motor vehicles. Aeronautics. Astronautics ,TL1-4050 - Abstract
In order to clarify the microstructure of Al-Mg-Sc high-strength aluminum alloy prepared by ultra-high speed laser melting deposition,and study the relationship between structure and properties,Al-Mg-Sc high-strength aluminum alloy was prepared by using 7075 aluminum alloy as matrix and self-developed equipment(LDF3000-40 laser melting deposition machine). The effect of laser scanning rate on the microstructure and tensile properties of the materials was investigated. The results show that there are no obvious defects such as pores and cracks in the samples deposited by ultra-high speed laser melting,but contain a few small keyholes. The samples are composed of fine α-Al equiaxial crystals and dispersed Al3(Sc,Zr)particles. The effect of scanning rate on mechanical properties is further studied by numerical simulation. It is found that the faster scanning rate of laser in the range of 0.1-1 m/s can reduce the accumulation of powder materials and porosity of the surface of the deposition layer,thus the mechanical properties can be improved. The maximum tensile strength is 303 MPa and elongation at break is 22.5%.
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- 2024
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9. Application of energy storage allocation model in the context of mitigating new energy source power fluctuation
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Yu Hao, Zhang XiaoYan, Chen MingYang, and Chen Fei
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Mitigate power fluctuation of new energy source ,First-order low-pass filtering algorithm ,Discrete fourier transformation ,Energy storage allocation ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
To address the impact of new energy source power fluctuations on the power grid, research has been conducted on energy storage allocation applied to mitigate the power fluctuations of new energy source. Firstly, based on the first-order low-pass filtering algorithm and discrete Fourier transform algorithm, the original power data of new energy sources were preprocessed to achieve the reconstruction of power signal. Subsequently, a more secure and reliable energy storage allocation model is constructed by taking into account the boundary conditions of energy storage charging and discharging efficiency, energy balance, state of charge, and target power output fluctuation. Then, a comprehensive Life-Cycle-Cost model for energy storage systems was developed and applied to economic evaluation of energy storage under two algorithms. Finally, the calculation case study analysis shows that the energy storage allocation model effectively improves the power fluctuations of new energy sources, represented by wind power, and ensure the safe and stable operation of energy storage system throughout the entire cycle, thus verifying the effectiveness and feasibility of the energy storage configuration model. Under fluctuation rate constraints of 10%, 15%, and 20%, the rated power required for the first-order low-pass filtering algorithm is 8.795 MW, 6.485 MW, and 4.022 MW, respectively, representing 18.32%, 13.51%, and 8.38% of the new energy source rated power(48 MW). The corresponding rated capacity required is 7.763 MWh, 3.675 MWh, and 1.123 MWh. In contrast, for the discrete fourier transform algorithm, the rated power required is 9.159 MW, 8.84 MW, and 5.78 MW, respectively, representing 19.08%, 18.42%, and 12.04% of the new energy source rated power. The corresponding rated capacity required is 2.01 MWh, 0.97 MWh, and 0.5 MWh. Form an economic feasibility perspective, the economic efficiency of energy storage allocation by discrete fourier transform algorithm is significantly better than allocated by the first-order low-pass filtering algorithm. For instance, when U10minup= 10%, the cost difference reaches a maximum of 1256 million ¥.
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- 2023
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10. Research on Collaborative Educational Mechanism of School-Enterprise Cooperation in Higher Vocational Colleges and Universities Based on Deep Learning
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Chen Fei
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synergistic effect ,equivalent matching ,multilayer linear model ,parenting performance ,school-enterprise cooperation ,00a35 ,Mathematics ,QA1-939 - Abstract
Although China’s higher vocational colleges and universities have achieved substantial results in school-enterprise cooperation, numerous problems have surfaced in practice. This paper analyzes the influence of strategic synergy, organizational synergy, knowledge synergy, and synergy effects within the context of school-enterprise cooperation. It also examines the role of equivalence matching factors in enhancing these synergy effects. Utilizing relevant data on school-enterprise cooperation, a synergistic education model was developed using a multilayer linear model to capture the interaction of latent variables. Subsequently, a performance measurement analysis was conducted to verify the scientific validity and effectiveness of collaborative efforts in higher vocational education. The results indicate that the synergistic performance in higher vocational institutions engaged in school-enterprise cooperation is 0.655, representing an increase of 0.107 compared to institutions without such collaboration. Implementing school-enterprise cooperation significantly enhances the synergistic performance of higher vocational institutions, thereby maximizing the benefits of this collaboration.
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- 2024
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11. Dynamic observation and risk factors analysis of deep vein thrombosis after hip fracture
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Yuxuan Cong, Baohui Wang, Chen Fei, Hong Zhang, Zhong Li, Yangjun Zhu, Yan Zhuang, Pengfei Wang, and Kun Zhang
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Medicine ,Science - Published
- 2024
12. In vitro and in vivo characterisations of Centella asiatica extract against Vibrio alginolyticus infection in whiteleg shrimp, Penaeus vannamei
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Wan Nurhafizah Wan Ibrahim, Hasnazifa Huzmi, Kok Leong Lee, Chen Fei Low, Alia Syafiqah Aznan, Nurul Aqilah Iberahim, Arief Izzairy Zamani, A. Abdul Razzak Laith, Abu Hena Mustafa Kamal, Hassan Ibrahim Sheikh, Musa Nadirah, Wan Sembok Wan-Zaliha, and Musa Najiah
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medicinal herb ,asiatic pennywort ,methanolic leaf extract ,alternative antimicrobial ,antioxidant ,aquaculture use ,Technology ,Technology (General) ,T1-995 ,Science ,Science (General) ,Q1-390 - Abstract
Methanolic leaf extracts of the medicinal herb Centella asiatica (Asiatic pennywort) were screened for in vitro and in vivo antimicrobial activities against Vibrio alginolyticus isolated from whiteleg shrimp, Penaeus vannamei. Phytochemical analyses were positive for tannins, saponins, steroids, and cardiac glycosides. Antioxidant test revealed antioxidant activity nearly as potent as that of 0.8 mg/mL ascorbic acid. Minimum inhibitory and bactericidal concentrations against V. alginolyticus were determined to be 0.79 and 12.50 mg/mL respectively. Scanning electron microscopy demonstrated disruptions of treated bacterial cells. 30 mg/kg extract supplementation achieved 85% survival of juvenile shrimp in a feeding trial. Histopathology showed increasingly fewer alterations in hepatopancreas from 10, 20 to 30 mg/kg supplementation, where 30 mg/kg preserved the tissues most with relatively complete structure including the star-shaped tubule lumen and various cell types. The present findings suggest the potential of C. asiatica as an alternative antimicrobial agent against V. alginolyticus as well as other Vibrio spp. and gram-negative bacteria in aquaculture.
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- 2023
13. Numerical Simulation of Circumferential Propagation of Surface Cracks on Pipeline Based on XFEM
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CHEN Fei, DING Ning, WANG Xinyi, ZHANG Fan, LIU Yanjun
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circular surface crack ,circumferential crack ,xfem ,crack propagation ,tensile displacement ,maximum stress ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Technology - Abstract
In order to study the influence of surface circumferential crack defects on pipelines, based on the extended finite element method(XFEM), a numerical simulation study was carried out on the crack propagation law of the X60 steel pipeline with circumferential circular surface cracks using the finite element software ABAQUS. Furthermore,the effects of crack location,internal pressure and initial crack size on the circumferential propagation of surface crack were discussed, and the maximum stress of the pipeline with cracked defects only under the action of internal pressure as well as the tensile displacement of the pipeline when the crack expands and penetrates the pipeline wall were analyzed.Results showed that the maximum stress on the pipeline was at the tip of the crack, and the stress there decreased after the crack expanded.When only under the action of internal pressure, the maximum stress of the pipe with circumferential cracks increased linearly with the rising of internal pressure, and the initial size and location of the crack had little effect on the maximum stress of the pipeline with circumferential cracks. Under the effect of axial displacement, the initial size of the crack had a significant influence on the displacement when the crack propagated. The axial displacement of the pipeline when the crack expands and penetrates the pipeline wall decreased rapidly with the rising of the crack size. When the crack size was in a certain range, the axial displacement of the pipeline when the inner wall crack expands and penetrates the pipe wall was smaller than the outer wall crack, which indicated that the crack on the inner wall was more dangerous. After the cracks increased to a certain size, the outer wall cracks became more dangerous.
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- 2022
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14. Geological Storage Conditions and Potential Analysis of Carbon Dioxide in the High-steep Fold Belt in Eastern Sichuan Basin
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Luan Jinhua, Zhang Ruigang, Zhao Haitong, Zhang Xiong, Mao Lingling, Zhang Yi, Hu Feng, Tian Heming, Dong Yi, Jiang Liangmei, and Chen Fei
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salt cavern reservoirs ,carbonate reservoirs ,triassic system ,eastern sichuan basin ,Environmental sciences ,GE1-350 - Abstract
Carbon sequestration refers to the technology of capturing carbon and storing it safely instead of directly discharging CO2 into the atmosphere. Rock salt is a promising CO2 reservoir, and the underground rock salt structure formed by salt cavern reservoirs in geological history has a natural sealing function. Storing carbon dioxide in salt caves can ensure that carbon dioxide is stably stored underground for a long time. However, at present, there are few studies on carbon sequestration in abandoned salt caves. This study analyses the characteristics of carbonate-evaporite strata in the high fold zone of eastern Sichuan and qualitatively evaluates Triassic carbonate-evaporite layers formed in the depth range of 800-3000 m in various sedimentary basins in Chongqing. A large set of carbonates-evaporites are developed in Chongqing, and the carbonate rocks near evaporites have low porosity and permeability, which can be used as CO2 storage caprock in salt cavities. Thick evaporated strata can also provide a good cover for CO2 storage in abandoned salt caves, which has great potential space resources.
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- 2024
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15. Incidence and risk factors of clinically important venous thromboembolism in tibial plateau fractures
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Pengfei Wang, Xinan Yan, Chen Fei, Binfei Zhang, Jian Xing, Kun Zhang, and Utku Kandemir
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Medicine ,Science - Abstract
Abstract While there are multiple reports on venous thromboembolism (VTE) associated with several orthopedic procedures, the knowledge regarding incidence and risk factors of VTE in tibial plateau fractures is limited. This study aimed to investigate the incidence and risk factors of clinically important venous thromboembolism (CIVTE) in patients with tibial plateau fractures. All adult patients who underwent surgical treatment of tibia plateau fractures between 2003 and 2018 in our level 1 trauma center were included in the study. All patients suspected CIVTE were assessed by the ultrasonography and/or CT scan. Univariate and multivariate analysis were used to evaluate the association between potential risk factors and CIVTE Variables. Thirty-nine of 462 patients (8.4%) developed clinically important venous thromboembolism, in which pulmonary embolism (PE) and deep vein thrombosis (DVT) were observed in 18 (3.9%) and 21 (4.54%) patients, respectively. Male gender (OR 9.75; 95% CI 2.34–40.66), spine injury (OR 9.51; 95% CI 3.39–26.64), other extremity injury (OR 3.7; 95% CI 1.58–8.66), length of stay in ICU (OR 1.14; 95% CI 1.09–1.2) were all risk factors for CIVTE. The incidence of CIVTE in tibial plateau fracture was relatively high (8.4%); The male gender, spine injury, other extremity injury, length of stay in ICU were the independent risk factors.
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- 2022
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16. Correction of severe lower extremity deformity with digital hexapod external fixator based on CT data
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Yufeng Lu, Jinfeng Li, Feng Qiao, Zhaochen Xu, Baogang Zhang, Bin Jia, Jinlong He, Liang Qi, Min Wang, Chen Fei, and Xiaoming Cao
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Multiplanar deformities ,Hexapod external fixator ,Electronic prescription ,Gradual correction ,Medicine - Abstract
Abstract Purpose Our goal was to examine the therapeutic effect of a self-designed digital six-axis external fixator technique for the correction of severe lower extremity deformities. Patients and methods Between January 2017 and December 2020, our institution employed self-developed digital hexapod external fixator technology (QSF), based on CT data, to gradually correct 28 severe tibial deformities, and 15 femurs underwent osteotomy and internal fixation. The mean patient age was 32.6 ± 14.3 years, and the mean follow-up duration was 27.4 ± 16.1 months. We also recoded and analyzed the values of preoperative and final follow-up MAD, mFTA, MPTA, LLD, mLDFA, LEFS, KSS, and functional score. Results The QSF adjustment duration was 21.4 ± 10.8 days, and the healing duration of the tibial osteotomy site was 17.6 ± 7.0 weeks. The preoperative MAD, mFTA, and MPTA were 54.1 ± 26.2 mm, 167.7 ± 15.7°, and 75.2 ± 12.0°, respectively. At the last follow-up, the MAD was 8.2 ± 9.9 mm, mFTA was 177.6 ± 3.4°, and MPTA was 87.6 ± 2.4°. Based on these data, we achieved significant improvement post operation. The preoperative LLD and mLDFA values were 13.8 ± 18 mm and 83.7 ± 10.8°, respectively, and the values were 7.6 ± 7.6 mm and 87.8 ± 2.6°, respectively, at the last follow-up. This indicated no significant difference in these values before and after the operation. Finally, the LEFS, KSS, and functional scores improved from preoperative 51.6 ± 11.2, 68.5 ± 11.7, and 67.8 ± 11.2 to postoperative 72.3 ± 6.1, 92.9 ± 3.4, and 94.2 ± 6.3, respectively. Conclusions Based on our analyses, the QSF technique accurately corrected severe multiplanar tibial deformities in adults. When combined with femoral osteotomy, satisfactory lower extremity alignment was obtained while correcting for femoral deformity. This technology has the advantages of simple operation, reliable fixation, less trauma, and less complications.
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- 2022
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17. Inter-annual variation patterns in the carbon footprint of farmland ecosystems in Guangdong Province, China
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Qiao Guotong, Chen Fei, Wang Na, and Zhang Dandan
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Medicine ,Science - Abstract
Abstract Carbon sequestration in farmland ecosystems is an important link in the world carbon cycle and plays an important role in regional carbon reduction. Guangdong, a major industrial and economic province in China, was used as the study area, and the period 2001–2020 was taken as the study period. The carbon emissions, sequestration, and footprint of farmland ecosystems in Guangdong were estimated using carbon emission factors for agricultural inputs that are closer to the actual situation in China. The study showed that: (1) Carbon average emissions from farmland in Guangdong during the study period was 3.7624 million t a−1, with a balanced overall trend of change, and that nitrogen fertilize applications was the main factor contributing to carbon emissions. (2) The carbon sink capacity of Guangdong farmland ecosystems showed an overall decreasing trend of 10.32%, with an average annual carbon sink of 19.0363 million t a−1. Paddy and sugar cane cultivations were the main factor of carbon sink in farmland. (3) The average annual carbon footprint of Guangdong's farmland ecosystems was 531,100 ha a−1, which was in a carbon surplus. Carbon surplus and footprint showed a decreasing trend year by year. The paper results provide a theoretical basis for the formulation of carbon emission reduction policies and industrial restructuring in Guangdong and provinces with the same industrial structure.
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- 2022
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18. Predictive value of National Institutes of Health Stroke Scale combined with serum high-sensitivity C-reactive protein at admission to ischemic stroke
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YUAN Li, ZHANG Jian-xing, WANG Su-jie, CHEN Fei-fei, HE Xiao-hong, and CHEN Li-li
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stroke ,brain ischemia ,c-reactive protein ,prognosis ,logistic models ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Objective To investigate the predictive value of the National Institutes of Health Stroke Scale (NIHSS) score combined with serum high-sensitivity C-reactive protein (hs-CRP) on admission to ischemic stroke. Methods A total of 487 patients with acute ischemic stroke admitted to the Department of Neurology of Tangshan Gongren Hospital from May 2018 to December 2019 were selected. The clinical data of patients were collected such as gender, age, hypertension, diabetes, coronary heart disease, previous stroke history, smoking and drinking history, serum low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), triglyceride (TG), hs-CRP, homocysteine (Hcy), fasting blood glucose (FBG). The NIHSS scale was used to evaluate the degree of neurological deficit at admission, and the modified Rankin Scale (mRS) was used to evaluate the prognosis when the patient was discharged. The mRS score ≤ 2 was defined as good prognosis, and the mRS score > 2 was defined as poor prognosis. Univariate and multivariate forward Logistic regression analysis were used to screen risk factors for poor prognosis of ischemic stroke, and the receiver operating characteristic (ROC) curve was used to compare the predictive value of NIHSS and hs-CRP levels at admission alone or in combination for patient prognosis. Results Compared with the good prognosis group, the poor prognosis group had higher proportions of male patients (χ2 = 4.729, P = 0.030), previous history of stroke (χ2 = 13.665, P = 0.000), and drinking alcohol (χ2 = 8.326, P = 0.004). The NIHSS score at admission (Z = -9.316, P = 0.000), serum FBG (Z = -3.234, P = 0.001), Hcy (Z = -3.652, P = 0.000) and hs-CRP (Z = -8.780, P = 0.000) level in poor prognosis group were higher than those in good prognosis group. Logistic regression analysis showed that the NIHSS score increased at admission (OR = 1.316, 95%CI: 1.223-1.417; P = 0.000), and the serum hs-CRP level increased (OR = 1.045, 95%CI: 1.032-1.058; P = 0.000) were risk factors for the prognosis of ischemic stroke. The area under the curve (AUC) predicted by the two combined (AUC = 0.903; 95%CI: 0.873-0.928, P = 0.000) exceeded than that of the NIHSS score at admission alone (AUC = 0.818; 95%CI: 0.781-0.852, P = 0.000) and the serum hs-CRP alone (AUC = 0.806; 95%CI: 0.768-0.840, P = 0.000); pairwise comparison found that the combination of the two was better than the NIHSS score at admission alone (Z = 3.187, P = 0.001) and serum hs-CRP alone (Z = 4.418, P = 0.000). Conclusions NIHSS score and high level of serum hs-CRP at admission are risk factors for poor prognosis of ischemic stroke. Combining NIHSS score and serum hs-CRP can provide an effective reference for clinical prediction of poor prognosis of ischemic stroke.
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- 2022
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19. Shared signaling pathway in pyroptosis and apoptosis in A549 cells induced by oxygen and glucose deprivation/recovery
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AN Yuxuan, XIAO Zongyi, WANG Xiaoyan, SONG Juan, CHEN Fei, and WANG Shouyong
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oxygen-glucose deprivation ,pyroptosis ,apoptosis ,hypotriploid alveolar basal epithelial a549 cells ,Medicine (General) ,R5-920 - Abstract
Objective To investigate the effects of oxygen and glucose deprivation/recovery (OGD/R) on apoptosis and pyroptosis of A549 cells, and to explore the possibility of the mutual regulation in apoptosis and pyroptosis. Methods A549 cells were resuscitated and cultured, randomly divided into control group, OGD/R group, OGD/R+pyroptosis inhibitor group (OGD/R+VX-765) and OGD/R+apoptosis inhibitor group (OGD/R+FMK). The apoptotic rate was detected by flow cytometry, the levels of pyroptosis markers IL-1β and IL-18 in the supernatant were measured by ELISA, and the expression of key molecules in pyroptosis and apoptosis at mRNA and protein levels were detected by RT-qPCR and Western blotting, respectively. Results The apoptotic rate was significantly increased in the OGD/R group than the control group (12.57±1.97 vs 3.67±0.64, P < 0.05), and the rate of the OGD/R+VX-765 group was decreased than that of the OGD/R group (5.97±1.28, P < 0.05). OGD/R resulted in obvious increased levels of IL-1β and IL-18 in the supernatant (17.35±0.44 vs 7.80±0.80 ng/L, 18.06±1.73 vs 7.99±0.11 ng/L, P < 0.05), but FMK treatment notably reversed the increases of 2 inflammatory factors (4.72±0.59, 10.24±1.42 ng/L, P < 0.05). OGD/R enhanced the mRNA and protein expression levels of key molecules of apoptosis and proptosis in A549 cells. While, VX-765 decreased the mRNA and protein levels of BID (1.12±0.18 vs 1.74±0.14, 1.01±0.10 vs 1.29±0.09, P < 0.05), and FMK reduced those of GSDME (0.94±0.05 vs 1.35±0.10, 0.52±0.03 vs 1.20±0.06, P < 0.05) when compared with the cells from the OGD/R group. Conclusion OGD/R can induce pyroptosis and apoptosis in A549 cells simultaneously, and there exists shared signaling pathway in pyroptosis and apoptosis. Pyroptosis and apoptosis inhibitors can simultaneously inhibit the 2 types of OGD/R-induced cell death.
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- 2022
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20. Anxiety among hospitalized COVID-19 patients: a case–control study from a tertiary teaching hospital in Malaysia
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Hui Jan Tan, Abdool Alleem Hj Shahren, Ching Soong Khoo, Chen Fei Ng, Wan Asyraf Wan Zaidi, Najma Kori, Petrick Periyasamy, Choon Leng Eu, Alvin Oliver Payus, and Rozita Hod
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anxiety ,COVID-19 ,hospitalized ,case control ,Generalized Anxiety Disorder-7 ,Psychiatry ,RC435-571 - Abstract
IntroductionAnxiety has been increasingly recognized as part of the psychosocial health issues in COVID-19 patients. However, the impact of this topic may be underestimated in low- and middle-income countries. This study aimed to estimate the prevalence of and risk factors of anxiety in COVID-19 patients compared to controls in a local tertiary teaching hospital in Malaysia.MethodsIn this case–control study, we analyzed data on adult patients aged 18 years and above hospitalized for COVID-19 infection with matched hospitalized controls. The demographic, clinical data and anxiety measures using the Generalized Anxiety Disorder-7 questionnaire were analyzed using univariate and multivariate analysis.Results86.6% in the COVID-19 group had anxiety, significantly higher than 13.4% in the control group (p = 0.001). The COVID-19 group was significantly associated with the GAD-7 severity (p = 0.001). The number of COVID-19 patients in the mild, moderate, and severe anxiety groups was 48 (84.2%), 37 (86%), and 18 (94.7%), respectively. Multiple logistic regression showed significant predictors for anxiety, including COVID-19 diagnosis and neurological symptoms. Anxiety was found 36.92 times higher in the patients with COVID-19 compared to those without COVID-19 (OR 36.92;95% CI 17.09, 79.78, p = 0.001). Patients with neurological symptoms were at risk of having anxiety (OR 2.94; 95% CI 1.03, 8.41, p = 0.044).DiscussionCOVID-19 patients experience a significant disruption in psychosocial functioning due to hospitalization. The burden of anxiety is notably high, compounded by a diagnosis of COVID-19 itself and neurological symptomatology. Early psychiatric referrals are warranted for patients at risk of developing anxiety symptoms.
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- 2023
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21. Research on the behaviour and mechanism of void welding based on multiple scales
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Shi Ruxing, Yu Xingsheng, Chen Huiqin, Jiao Yongxing, Chen Juan, Chen Fei, and He Sizhe
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void welding ,numerical simulation ,physical simulation ,molecular dynamics ,Technology ,Chemical technology ,TP1-1185 ,Chemicals: Manufacture, use, etc. ,TP200-248 - Abstract
As the core foundation of major national equipment, large forgings have a great influence on the national economic construction, the development of national defence equipment and the development of modern cutting-edge science and technology. In the production of large forgings, welding the internal void of forgings is a technical problem that directly affects the quality of large forgings. In view of the phenomenon of void welding in large forgings, the behaviour and mechanism of void welding were deeply studied based on the stretching test and molecular dynamics simulation, combined with a lot of theoretical analysis. The results show that multi-pass stretching deformation is a kind of plastic deformation process which can eliminate void defects. When the forging ratio reaches 2.2, the void can be welded completely and the tensile strength can be restored to the level of the matrix. With the increase of compression deformation, the stress will increase sharply, especially at the grain boundary. In addition, the main void welding mechanism of 30Cr2Ni4MoV steel is the recrystallization and grain growth mechanism. Recrystallization and grain growth are of great significance for promoting the reduction of void volume and realizing metallurgical bonding of the interface.
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- 2023
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22. Analysis of radionuclide levels in infant milk powder imported from Japan through cross-border e-commerce network sales
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GAO Fei, CHEN Fei, JIANG Shan, FENG Feng, ZHANG Zhen, and ZHANG Feng
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imported from japan ,infant milk powder ,radionuclide ,risk assessment ,Food processing and manufacture ,TP368-456 ,Nutrition. Foods and food supply ,TX341-641 - Abstract
ObjectiveA sample survey was conducted on the radionuclide content in imported Japaneseinfant milk powder sold by cross-border e-commerce in order to provide basic data for risk assessment.MethodsRandom sampling was conducted on imported Japanese infant milk powder sold by online cross-border e-commerce, including different brands and types. The strontium-90 activity concentration of milk powder samples was analyzed by HDEHP extraction chromatography (rapid method), γ radionuclide activity concentration was analyzed by γ energy spectrometer, total αand total β activity concentration was analyzed by low background α, β measuring instrument.Then, the Radionuclide content in infant milk powder was compared with that from Chinese and imported from the Netherlands.ResultsThe artificial γ radionuclides (60Co, 103Ru, 106Ru, 131I, 134Cs, 137Cs) were not detected in the imported milk powder samples from Japan. strontium-90 activity concentration of 5 milk powder samples imported from Japan was lower than the method detection limit (MDL). The strontium-90 activity concentration of other samples ranged from 0.13 to 0.18 Bq/kg. Only natural radionuclides 238U was detected in all samples, which ranged from 33.5 to 109 Bq/kg. The activity concentration of total α and total β ranged from 0.05 to 0.12 Bq/kg. The content of all radionuclides was lower than the limit of Chinese national food safety standards (GB18871—2002 and GB14882—94).ConclusionThe results showed that 60% of the samples of infant milk powder imported from Japan on online cross-border e-commerce platforms were produced in Areas banned from import by China . Although the radionuclide content detected did not exceed China’s limits, considering the limitations of the sampling quantity and scope, consumers still need to be aware of the risk of excessive levels of radionuclides in infant milk powder imported from Janan. With the follow-up measures of the Fukushima nuclear accident, the relevant regulatory authorities still need strengthen random inspection and monitoring.
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- 2022
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23. Experimental study on fire prevention and extinguishing of cryogenic inert gas slurry
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ZHANG Xinhai, DOU Kai, ZHANG Guowei, CHENG Wangshou, LI Xunguang, ZHU Hui, ZHAO Bin, CHEN Fei, and YANG Shaoxiong
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fire preventing and extinguishing ,cryogenic inert gas slurry ,high temperature loose coal ,cooling performance ,phase transition ,Mining engineering. Metallurgy ,TN1-997 - Abstract
In order to effectively prevent and control the coal mine spontaneous combustion fire hazard, the research on the technology of cryogenic inert gas slurry was carried out aiming at the shortcomings of the existing inert gas fire-fighting technology, such as poor cooling effect and complicated conveying process. The experimental system for the preparation of cryogenic inert gas slurry and the cooling of heated loose coal was independently designed, and the temperature changes at different measuring points and the concentrations of CO and O2 in the experimental chamber were obtained under different injection flow rates. Results show that LCO2 (liquid CO2) is mixed with LN2(liquid nitrogen) in the pipeline transmission process, and injected into the experimental chamber in the form of solid, liquid and gas three-phase. The phase change occurs rapidly, the ordered structure is damaged, and a large amount of heat is absorbed. The temperature of air and coal in the box drops rapidly, and the fire prevention performance is better when large flow rate is injected. By comparing the fire-extinguishing effect of injecting liquid nitrogen and liquid carbon dioxide separately, it is concluded that the anti-fire-extinguishing technology of inert gas slurry has the advantages of both liquid nitrogen and liquid carbon dioxide, and the cooling and oxygen reduction effect is significant, and the anti-fire-extinguishing effect is better than that of liquid nitrogen and liquid carbon dioxide.
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- 2021
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24. Experimental study on influence of high temperature baking on magnetic properties of Nalinmiao rock
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ZHANG Xinhai, DOU Kai, LI Jingwen, CHENG Wangshou, LI Xunguang, ZHU Hui, ZHAO Bin, CHEN Fei, and YANG Shaoxiong
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burnt rock ,magnetic anomaly ,fire source exploration ,magnetic susceptibility ,coalfield fire ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Magnetic anomaly is an important geophysical feature of coal field fires. In order to study the magnetic change law of high-temperature heated rocks and provide effective guidance for the application of magnetic method in the delineation of fire zones, the susceptibility measurement system was used to determine the magnetic susceptibility of Nalinmiao 3-1 coal roof sandstone. The effects of temperature, particle size, and magnetic field strength on the magnetic susceptibility of the samples were studied. The results show that the magnetic susceptibility of the burnt rock in the whole range of 25 ℃ to 600 ℃ increases with the increase of temperature, and decreases with the increase of the external magnetic induction intensity. When the heated temperature is less than 400 °C, the smaller the particle size of the sample, the greater the magnetic susceptibility; the effect of high temperature baking on the composition and structure of the rock is analyzed by X-ray diffraction experiments, indicating that during the high temperature baking of the rock, FeCO3 is oxidized into Fe3O4, which is the main reason why burnt rock is more magnetic than normal rock.
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- 2021
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25. Association Between Osteogenic Differentiation in Soft Tissue Lump and Clinicopathological Characteristics of Osteosarcoma Patients
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WU Zhaoyang, WANG Shenglin, SHEN Rongkai, CHEN Fei, LIN Jianhua, ZHU Xia, and ZHANG Zhenzhen
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osteosarcoma ,osteogenesis ,chemotherapy ,prognosis ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Objective To investigate the association between the osteogenic differentiation in the soft tissue lump and the clinicopathological characteristics of osteosarcoma patients. Methods We retrospectively reviewed the clinical data of conventional osteosarcoma patients with soft tissue lumps, including Enneking stages, chemotherapy sensitivity, overall survival and post-metastatic survival time. The ossification level in soft tissue lumps was assessed by imaging and the proportion of osteoid matrix was assessed by pathological examination. Results A total of 189 cases were included in this study. In patients with Enneking IIIB, non-osteoblastic, partially osteoblastic and osteoblastic types accounted for 30.2%, 9.6% and 6.3%, respectively. Non-osteoblastic osteosarcoma patients had a higher rate of initial metastasis (P < 0.05); Chemotherapy efficiency of non-osteoblastic, partially osteoblastic and osteoblastic types were 60.5%, 59.6% and 31.3%, respectively. The osteoblastic osteosarcoma held the worst rate of chemotherapy sensitivity (P < 0.05). The overall survival of non-osteoblastic osteosarcoma was shorter than those of partially osteoblastic and osteoblastic types (P < 0.05). Post-metastatic survival time of osteoblastic osteosarcoma was longer than that of non-osteoblastic osteosarcoma (P=0.078). Conclusion For conventional osteosarcoma, the osteogenesis level in soft tissue lumps is related to the surgical stage, chemotherapy sensitivity and prognosis of tumors, which may provide guidance for the individual decision regarding chemotherapy and surgery timing on patients.
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- 2021
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26. Study on air flow control parameters of long-pressure and short-extraction ventilation air outlets in heading face
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GONG Xiaoyan, PENG Gaogao, SONG Tao, FENG Xiong, CHEN Fei, LIU Hui, XIE Pei, and XUE He
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heading face ,long-pressure short-extraction ventilation ,outlet air flow control parameters ,air speed ,dust concentration ,niche genetic algorithm ,Mining engineering. Metallurgy ,TN1-997 - Abstract
The air flow at the air outlet cannot be dynamically adjusted according to the actual needs of the tunneling process under the long-pressure and short-extraction ventilation mode of the heading face, resulting in unreasonable air flow distribution and serious dust accumulation. The existing studies on the air flow distribution and dust reduction effect of long-pressure and short-extraction ventilation outlet at the heading face are only single analyses of the effect of the change of the air duct air outlet parameters on the air flow distribution and dust reduction effect in the heading face, without considering the interactive effect of each parameter on the dust field migration distribution. Moreover, there is no in-depth research on how the parameters of the air outlet can be changed comprehensively to achieve the optimal ventilation and dust reduction effect in different tunneling stages. In order to solve the above problems, taking the S1204 heading face of Shenmu Ningtiaota Mine in Yulin, Shaanxi Province as the research object, a finite element model of air flow control with variable air outlet parameters is established. The effect of the change of air duct air outlet parameters on the air flow and dust concentration migration distribution is simulated and analyzed. Through numerical analysis, the air outlet diameter, horizontal right deviation angle and vertical up deviation angle of the air duct are selected as the air flow dynamic control parameters of the air outlet, and the air speed and dust concentration data of the driver position and the pedestrian position on the return air side after the adjustment of different air flow control parameters are extracted. Through the niche genetic algorithm, the extracted air flow control data are mined and analyzed with the lowest dust concentration at the driver position and the pedestrian position on the return air side as the optimization object. And the optimal air flow control parameters are obtained for the closest distance of 5 m and the farthest distance of 10 m between the air outlet of S1204 heading face and the driving end face. At 5 m, the air outlet diameter is 1.1-1.2 m, the horizontal right deviation angle is 10-15°, and the vertical up deviation angle is 3-6°. At 10 m, the air outlet diameter is 0.8-0.9 m, the horizontal right deviation angle is 0-5° and vertical up deviation angle is 0-3°. A 1∶5 similar simulation test platform for intelligent control of air flow of the heading face of S1204 is built, and the optimal air flow control parameters are tested and analyzed. The results show that the dust concentration at the driver position is reduced by up to 52.3%, and the dust concentration at pedestrian position on the return air side is reduced by up to 60.6%, which verifies the accuracy of the optimal air flow control parameters.
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- 2021
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27. Constructing robust superhydrophobic interface with self-assembled Cu6Sn5 arrays and application in copper corrosion inhibition
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GAO Zhao-qing, WANG Chen, CHEN Yin-bo, SHANG Sheng-yan, CHEN Fei, MA Hai-tao, and WANG Yun-peng
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self-assembling ,scallop-like cu6sn5 ,metallurgical bonding ,superhydrophobicity ,corrosion resistance ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
The superhydrophobic scallop-like Cu6Sn5 micro/nano structure were successfully constructed on pure copper substrate by heat-induced Cu/Sn interfacial metallurgical reaction and simple chemical modification process. The microstructure, chemical composition and corrosion resistance of as-prepared samples were characterized by field emission scanning electron microscopy and X-ray photoelectron spectroscopy, etc. The results show that the averaged shear resistance strength between micro Cu6Sn5 and Cu substrate is higher than 40 MPa. After modified with myristic acid and Cu2+, copper myristate with low surface energy is formed on the armor Cu6Sn5 surface. The wetting angle of water droplets on as-modified surface is higher than 150° and its rolling angle is 7.2°. Compared with pure copper, the self corrosion current density of the samples modified by copper myristate in 3.5%NaCl(mass fraction) solution is about 1/10 of that of the samples before modification,showing better corrosion resistance. Based on the metallurgical bonding mechanism between intermetallic compounds and metal matrix, the armor formation strategy of metal materials in micro-scale by heat-induced interfacial reaction is proposed, which can successfully solve the open and key scientific problem of low mechanical stability for artificial superhydrophobic interface.
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- 2021
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28. Research on law of magnetic anomaly variation with depth in fire area of Ordos Coalfield
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ZHANG Xinhai, CHENG Wangshou, LI Xunguang, MIAO Yuhui, DOU Kai, ZHU Hui, ZHAO Bin, CHEN Fei, and YANG Shaoxiong
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coal field fire ,magnetic anomaly ,magnetic susceptibility ,mutation ,buried depth ,spontaneous combustion ,fire control ,Mining engineering. Metallurgy ,TN1-997 - Abstract
By comparing the change law of magnetic susceptibility of Ordos coal rock at normal temperature and during the temperature increase: as the temperature increases, the magnetic susceptibility also increases, and the composition of coal rock before and after heating is analyzed by X-ray diffractometer. It is found that the main reason for this change is that the ferromagnetic mineral composition of coal rock is changing during the heating process. This is used as the basis for the magnetic anomaly changes in the coalfield fire area. According to the theory of the gravitational potential field and magnetic potential field of the classic point, the coal bed fire area is used as a typical physical model to determine, and the Poisson formula method is used to determine the gravitational potential and magnetic potential. The second-order derivative of the cuboid gravitational potential is derived from the Poisson relationship, and the forward relationship of the magnetic anomaly of the coal field fire zone is obtained by integration. The magnetic anomaly characteristics of the coalfield fire zone model are calculated and simulated using Matlab. The results show that: as the depth increases, the extreme value of the magnetic field strength exhibited by the target body continues to decrease; the mutation rate of the intensity decreases continuously as it approaches the range of the anomaly; as the burial depth of the coalfield fire increases, the extent of magnetic anomalies has also continuously expanded to surrounding areas.
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- 2021
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29. Single-shot imaging of surface molecular ionization in nanosystems
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Sun Fenghao, Li Hui, Song Shanshan, Chen Fei, Wang Jiawei, Qu Qiwen, Lu Chenxu, Ni Hongcheng, Wu Botao, Xu Hongxing, and Wu Jian
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nanoparticle ,shock wave ,strong-field ionization ,surface molecules ,velocity map imaging ,Physics ,QC1-999 - Abstract
Using single-shot velocity map imaging technique, explosion imaging of different ion species ejected from 50 nm SiO2 nanoparticles are obtained excitedly by strong near-infrared and ultraviolet femtosecond laser fields. Characteristic momentum distributions showing forward emission of the ions at low excitation intensities and shock wave behaviors at high intensities are observed. When the excitation intensity is close to the dissociative ionization threshold of the surface molecules, the resulting ion products can be used to image the instant near-field distributions. The underlying dynamics of shock formation are simulated by using a Coulomb explosion model. Our results allow one to distinguish the ultrafast strong-field response of various molecular species in nanosystems and will open a new way for further exploration of the underlying dynamics of laser-and-nanoparticle interactions.
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- 2021
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30. Unrolling Plug-and-Play Gradient Graph Laplacian Regularizer for Image Restoration
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Cai, Jianghe, Cheung, Gene, and Chen, Fei
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Electrical Engineering and Systems Science - Image and Video Processing - Abstract
Generic deep learning (DL) networks for image restoration like denoising and interpolation lack mathematical interpretability, require voluminous training data to tune a large parameter set, and are fragile in the face of covariate shift. To address these shortcomings, we build interpretable networks by unrolling variants of a graph-based optimization algorithm of different complexities. Specifically, for a general linear image formation model, we first formulate a convex quadratic programming (QP) problem with a new $\ell_2$-norm graph smoothness prior called gradient graph Laplacian regularizer (GGLR) that promotes piecewise planar (PWP) signal reconstruction. To solve the posed unconstrained QP problem, instead of computing a linear system solution straightforwardly, we introduce a variable number of auxiliary variables and correspondingly design a family of ADMM algorithms. We then unroll them into variable-complexity feed-forward networks, amenable to parameter tuning via back-propagation. More complex unrolled networks require more labeled data to train more parameters, but have better overall performance. The unrolled networks contain periodic insertions of a graph learning module, akin to a self-attention mechanism in a transformer architecture, to learn pairwise similarity structure inherent in data. Experimental results show that our unrolled networks perform competitively to generic DL networks in image restoration quality while using only a tiny fraction of parameters, and demonstrate improved robustness to covariate shift.
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- 2024
31. Modeling the Impact of Cotton Production on Economic Development in Benin: A Technological Innovation Perspective
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Dafia Chabi Simin Najib, Chen Fei, Azer Dilanchiev, and Samson Romaric
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Benin republic ,cotton production ,economic growth ,vector error correction ,technological innovation ,Environmental sciences ,GE1-350 - Abstract
This research provides an in-depth understanding of cotton production in Benin. The analysis explored the effects of cotton production on economic growth using a vector error correction model (VECM). Prior to the VECM, a descriptive analysis was conducted on a time series database collated over 56 years (1965–2021) from national and international organizations including World Bank, the United States Department of Agriculture, and the National Accounts. Depending on the availability of the information over this period, the data were trimmed down to enable a better overview of the trend for variable of interest. Thus, the review of the trend for agricultural land (hectares) for cotton observed from 1965 to 2021 revealed that the trend evolves over the years in three different patterns, while the yields demonstrate four patterns over the same period. For the VECM analysis that permits to understand the long- and short-term relation, the time bound covers 30 years from 1990 to 2019 given the availability of data for all the variables used for the model. The findings highlighted that a strong and positive connection is found between cotton export and economic growth and a long-term relation between the human capital and the economic growth in Benin. A rapid human capital development will increase quality of the employment generation, and the country’s economy will adjust upward. Furthermore, a short-run coefficient unveils feedback necessary in a relative level of investment to bring back the economic growth to equilibrium. From these findings discussed in this study, the government of Benin is commended to diversify the production of cotton through a town target policy.
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- 2022
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32. Preparation of W18O49/C-TiO2 direct Z-scheme photocatalyst and photocatalytic water splitting for H2 production
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ZHANG Kun, YANG Yu-rong, CHEN Fei-yang, QI Qi, ZHANG Chun-guang, and GAO Fan
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w18o49 ,c-tio2 ,z-scheme ,photocatalytic water splitting ,h2 production ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
W18O49/C-TiO2 direct Z-scheme photocatalyst was prepared by a simple hydrothermal method. The structure, morphology, transport properties of photogenerated carriers and energy band structure were characterized by XRD, SEM, TEM, HRTEM, PL and other measurements. Under simulated sunlight illumination, the photocatalytic water splitting performance for hydrogen (H2) production and quantum efficiency were studied without adding any sacrificial agent. The results show that the construction of W18O49/C-TiO2 direct Z-scheme photocatalyst can significantly improve light absorption, accelerate the separation and transport of photogenerated carriers, and enable more photogenerated electrons participate in the photocatalytic reduction reaction, so the sample possesses high efficient photocatalytic activity. The photocatalytic H2 production tests show that under simulated sunlight illumination, the W18O49/C-TiO2 direct Z-scheme heterojunction can achieve H2 production rate of 209 μmol·h-1·g-1 without adding any sacrificial agents. It also exhibits strong photocatalytic stability; the H2 production remains unchanged during the 24 h cycle test.
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- 2021
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33. Inductively Coupled Plasma-Mass Spectrometric Analysis of Nickel and Scandium in Carbonate Rock Samples and Interference Correction Methods
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CHEN Fei-fei, RAN Jing, XU Guo-dong, CHENG Jiang, and CHEN Yu
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carbonate rock ,nickle ,scandium ,inductively coupled plasma-mass spectrometry ,interference correction ,Geology ,QE1-996.5 ,Ecology ,QH540-549.5 - Abstract
BACKGROUND Inductively coupled plasma-mass spectrometry (ICP-MS) has been widely used in the determination of trace elements in carbonate rocks. Due to the low Ni (1.6-50.5μg/g) and Sc (0.3-6μg/g) in carbonate rocks, the signal values are obviously interfered by high CaO (up to 56%) and MgO (up to 21%) during ICP-MS determination, resulting in the test value much higher than the true value. OBJECTIVES To solve the problem of non-mass spectrum interference and mass spectrum interference of Ni and Sc during ICP-MS analysis of carbonate rocks and use appropriate correction method. METHODS The single standard series of Ca and Mg and national first-level reference materials of carbonate rocks were used to study the interference of high content of Ca and Mg on Ni and Sc in the carbonate during ICP-MS analysis. Testing of the single standard series was aim to explore ways of interference on Ni and Sc by high content of Ca and Mg in solution. The national first-level reference material of carbonate rock was further selected as the calibration carrier to eliminate the matrix effect of Mg. At the same time, according to the good linear relationship between the content of CaO in the sample solution and the interference degree of Ni and Sc, the interference equations of CaO and △Ni and △Sc were fitted respectively, and used for interference deduction of Ni and Sc in several national first-level reference materials and unknown samples of carbonate rocks. The accurate test values of Ni and Sc in carbonate rocks by ICP-MS were obtained. RESULTS It was found that the high content of Mg had a non-mass spectrometric interference matrix effect on the analysis of Ni and Sc. High content of Ca forms oxides, hydroxides and polyatomic ions, resulting in mass spectrometric interference on Ni and Sc. The degree of interference had a good linear relationship with the Ca content in the solution. Compared with a single standard to perform interference correction on actual samples, this method used national first-level standard materials as the calibration carrier, which overcomed the interference of matrix effects. Verified by GBW07108 and other five national primary standard materials of carbonate rocks, test values agreed with the standard values, with a relative standard deviation (RSD, n=10) of less than 5.5%. Correction results of the unknown carbonate samples were compared with the results of the inductively coupled plasma-optical emission spectroscopy (ICP-OES) and the X-ray fluorescence spectrometer (XRF), respectively, the relative deviation was less than 15%. CONCLUSIONS The correction method proposed in this paper has solved the mass spectral interference and non-mass spectral interference in ICP-MS analysis of Ni and Sc in carbonate rocks. The method is simple and feasible, and the results are accurate and reliable.
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- 2021
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34. An NMR Study on Two New β-Dihydroagrofuran Compounds in Celastrus angulatus Maxim
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LIAO Huai-yu, HAN Hong-yuan, CHEN Fei, ZHANG Hai-yan, YANG Jing, and ZHAO Tian-zeng
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nuclear magnetic resonance (nmr) ,celastrus l. ,β-dihydroagrofuran ,celastrus angulatus maxim ,Electricity and magnetism ,QC501-766 - Abstract
Two new β-dihydroagrofuran compounds, 1β,2β,15-triacetoxy-8α-(α-methyl)-butanoyloy-9β-benzoxy-4α,6α- dihydroxy-β-dihydroagrofuran (compound I) and 1β,15-diacetoxy-8α-(α-methyl)-propionyloxy-2β,9β-dibenzoxy-4α,6α- dihydroxy-β-dihydroagrofuran (compound II), were isolated from Celastrus angulatus Maxim. The chemical shifts of the two new compounds were assigned by one- and two-dimensional nuclear magnetic resonance (NMR) techniques. Their structures were elucidated.
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- 2021
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35. Voltage control strategy for distribution network based on SoC FPGA hardware parallel computing
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DANG Haotian, LIU Dong, CHEN Fei, ZHAO Xianping, LIU Siyang, and WANG Hongyu
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active distribution network ,voltage control ,edge computing ,system on chip field programmable gate array (soc fpga) ,parallel computing ,genetic algorithm ,Applications of electric power ,TK4001-4102 - Abstract
With the development of active distribution network and Internet of Things technology,the access of reactive power equipment is becoming more complicated and marginalized,and the related computing of voltage control is also developing towards edge computing. Due to the limited computing power,the pure software calculation of edge nodes takes a long time,which cannot meet the requirements of real-time control. Aiming at this problem,a distribution network voltage control strategy based on system on chip field programmable gate array (SoC FPGA) hardware parallel computing is proposed. Firstly,the software and hardware computing framework based on SoC FPGA is designed. Then,targeted improvements are made to the distribution network voltage control model and genetic algorithm solution method for FPGA computing. Finally,the FPGA hardware solution structure is designed in modules. The verification of example scenarios shows that,compared with the pure software solution method of edge nodes,the average solution efficiency of the proposed strategy in scenarios where voltage is lower than lower limit and where voltage exceeds upper limit is increased by 2.41 times and 2.15 times respectively,which can effectively improve the real-time performance of voltage control.
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- 2022
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36. Real-time calculation method of mine ventilation network based on ultrasonic full-section wind measurement
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SONG Tao, WANG Jianwen, WU Fengliang, ZHANG Guoqun, CHEN Fei, FENG Xiong, and LI Longqing
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mine ventilation ,ventilation network ,ultrasonic full-section wind measurement ,real-time calculation of ventilation network ,static calculation of ventilation network ,redundant air volume ,fixed air volume method ,Mining engineering. Metallurgy ,TN1-997 - Abstract
The wind flow in underground coal mine is changing all the time. The coal mine ventilation network solution is a static calculation method, which can not solve the dynamic wind flow in real time, and requires wind speed sensor to obtain the dynamic wind flow data. However, the current wind speed sensor has poor stability and incomplete coverage. In order to solve the above problems, a real-time calculation method of mine ventilation network based on ultrasonic full-section wind measurement is proposed. The time difference between downwind and upwind of ultrasonic propagation between two points is used to measure the wind speed of the whole section of the roadway. The wind speed measurement result is independent of the sound speed and is not affected by the parameters such as the sound speed, temperature and humidity and air pressure. The problem that the air duct of the traditional wind speed sensor is easily blocked by mine dust is avoided. The resolution of the wind measuring device reaches 0.03 m /s. By continuously collecting the real-time working conditions of air volume and air pressure of main fans and the real-time air volume of some shafts and roadways, the ventilation network is calculated. And the fixed air volume method is used to integrate the monitored air volume into the ventilation network, and the real-time air volume of the whole ventilation network can be obtained through calculation. The Lagrangian multiplier method is used to correct and calculate the air volume and wind resistance in real time, so as to solve the problems of unbalanced air volume of nodes caused by redundant air volume monitoring branches and unbalanced air pressure of loop caused by fluctuation of the wind resistance. It is verified by an example that the calculation results of the real-time calculation method are highly consistent with the monitoring values. At the same time, the results strictly follow the constraints of the loop air pressure balance and the node flow balance. The real-time calculation of the ventilation network with 1 319 branches and 945 nodes in Ningtiaota Coal Mine is carried out. The time for one calculation is only 0.9 s, the number of iteration convergence is about 105, and the calculation results are continuously updated with time. The results verify the feasibility of the real-time calculation method.
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- 2022
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37. A Comprehensive Review with Future Insights on the Processing and Safety of Fermented Fish and the Associated Changes
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Sharon Xi Ying Chan, Nursyah Fitri, Nurul Syahidah Mio Asni, Nor Hafiza Sayuti, Ummi Kalthum Azlan, Wasim S. M. Qadi, Esraa Adnan Dawoud Dawoud, Nurkhalida Kamal, Murni Nazira Sarian, Mohd Aizuddin Mohd Lazaldin, Chen Fei Low, Sarahani Harun, Hamizah Shahirah Hamezah, Emelda Rosseleena Rohani, and Ahmed Mediani
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fish ,fermentation ,health benefits ,omics ,processing ,preservation ,Chemical technology ,TP1-1185 - Abstract
As an easily spoiled source of valuable proteins and lipids, fish is preserved by fermentation in many cultures. Over time, diverse types of products have been produced from fish fermentation aside from whole fish, such as fermented fish paste and sauces. The consumption of fermented fish products has been shown to improve both physical and mental health due to the composition of the products. Fermented fish products can be dried prior to the fermentation process and include various additives to enhance the flavours and aid in fermentation. At the same time, the fermentation process and its conditions play a major role in determining the quality and safety of the product as the compositions change biochemically throughout fermentation. Additionally, the necessity of certain microorganisms and challenges in avoiding harmful microbes are reviewed to further optimise fermentation conditions in the future. Although several advanced technologies have emerged to produce better quality products and easier processes, the diversity of processes, ingredients, and products of fermented fish warrants further study, especially for the sake of the consumers’ health and safety. In this review, the nutritional, microbial, and sensory characteristics of fermented fish are explored to better understand the health benefits along with the safety challenges introduced by fermented fish products. An exploratory approach of the published literature was conducted to achieve the purpose of this review using numerous books and online databases, including Google Scholar, Web of Science, Scopus, ScienceDirect, and PubMed Central, with the goal of obtaining, compiling, and reconstructing information on a variety of fundamental aspects of fish fermentation. This review explores significant information from all available library databases from 1950 to 2022. This review can assist food industries involved in fermented fish commercialization to efficiently ferment and produce better quality products by easing the fermentation process without risking the health and safety of consumers.
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- 2023
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38. Analysis of Serum Vitamin D Level and Related Factors in Patients With Restless Legs Syndrome
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Hui Miao Liu, Miao Chu, Chen Fei Liu, Ting Zhang, and Ping Gu
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restless legs syndrome ,vitamin D ,severity of symptoms ,sleep quality ,depression ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Objective: This study aimed to detect serum vitamin D (VitD) levels in patients with primary restless legs syndrome (RLS). The further objective was to analyze the relationship of VitD levels with the severity of RLS symptoms, sleep, anxiety, and depression.Methods: The serum 25-hydroxyvitamin D [25(OH)D] levels of 57 patients with primary RLS and the healthy physical examinees in our hospital during the same period were detected. The International Restless Legs Syndrome Study Group (IRLSSG) rating scale for measuring RLS severity and Pittsburgh Sleep Quality Index (PSQI) Scale, 24-item Hamilton Depression Rating Scale (HAMD24), and 14-item Hamilton Anxiety Scale (HAMA14) were used to assess the severity of symptoms, sleep, and emotional state of patients with RLS. Based on VitD level and IRLSSG score, they were grouped for analysis.Results: The serum 25(OH)D level was significantly lower in patients with RLS than in healthy controls, and the incidence of insufficient serum VitD levels was significantly higher in patients with RLS than in healthy people (both P < 0.05). The serum VitD level was significantly lower in (extremely) severe patients with RLS than in mild to moderate patients with RLS (P < 0.05). The IRLSSG scale score and HAMD24 score were significantly higher in patients with RLS with insufficient serum VitD levels than those with normal serum VitD levels (both P < 0.05). Correlation analysis of IRLSSG scale score with serum VitD level and each scale score in patients with RLS showed that IRLSSG scale score was negatively correlated with VitD level, but positively correlated with PSQI, HAMA14, and HAMD24 scores. The results of correlation analysis between serum VitD levels and each scale score in patients with RLS indicated that serum VitD levels were negatively correlated with IRLSSG scale scores, PSQI scores, and HAMD24 scores.Conclusion: The serum VitD level is generally lower in patients with RLS than in healthy people, and lower serum VitD level is associated with more severe symptoms of RLS, worse quality of sleep, and worse depression.
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- 2021
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39. Patterned Electrode Assisted One‐Step Fabrication of Biomimetic Morphing Hydrogels with Sophisticated Anisotropic Structures
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Qing Li Zhu, Chen Fei Dai, Daniel Wagner, Olena Khoruzhenko, Wei Hong, Josef Breu, Qiang Zheng, and Zi Liang Wu
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biomimetic structures ,electrical orientations ,hydrogels ,morphing materials ,soft actuators ,Science - Abstract
Abstract Anisotropic structures are ubiquitous in nature, affording fascinating morphing behaviors. Biomimetic morphing materials can be developed by spatially controlling the orientations of molecules or nanofillers that produce anisotropic responses and internal stresses under external stimuli. However, it remains a serious challenge to fabricate materials with sophisticated anisotropic architectures. Here, a facile strategy to fabricate morphing hydrogels with elaborately ordered structures of nanosheets, which are oriented under distributed electric field and immobilized by polymerization to form a poly(N‐isopropylacrylamide) matrix, is proposed. Diverse sophisticated anisotropic structures are obtained by engineering the electric field through the patterns and relative locations of the electrodes. Upon heating, the monolithic hydrogels with through‐thickness and/or in‐plane gradients in orientation of the nanosheets deform into various three‐dimensional configurations. After incorporating gold nanoparticles, the hydrogels become photoresponsive and capable of programmable motions, for example, dynamic twisting and flipping under spatiotemporal stimuli. Such a strategy of using patterned electrodes to generate distributed electric field should be applicable to systems of liquid crystals or charged particles/molecules to direct orientation or electrophoresis and form functional structures. The biomimetically architectured hydrogels would be ideal materials to develop artificial muscles, soft actuators/robots, and biomedical devices with versatile applications.
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- 2021
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40. Costability of Comodules
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Chen, Fei Yu
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Mathematics - Category Theory ,Mathematics - Algebraic Topology ,Mathematics - Rings and Algebras ,18N70 - Abstract
Given a ring $R$, we have a classical result stating that the ordinary category of modules is the abelianization of the category of augmented $R$-algebras. Analogously, using the framework of infinity categories and higher algebra, Francis showed that the infinity category of $R$-modules is the stabilization of the infinity category of augmented $R$-algebras. In this work we show a dual result for coalgebras over a cooperad $Q$: namely that given a coalgebra $C$, comodules over $C$ are the costabilization of coalgebras over $C$, which is the universal stable category with a finite colimit preserving functor to coalgebras over $C$.
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- 2024
41. MULAN: A Multi Layer Annotated Dataset for Controllable Text-to-Image Generation
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Tudosiu, Petru-Daniel, Yang, Yongxin, Zhang, Shifeng, Chen, Fei, McDonagh, Steven, Lampouras, Gerasimos, Iacobacci, Ignacio, and Parisot, Sarah
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Computer Science - Computer Vision and Pattern Recognition - Abstract
Text-to-image generation has achieved astonishing results, yet precise spatial controllability and prompt fidelity remain highly challenging. This limitation is typically addressed through cumbersome prompt engineering, scene layout conditioning, or image editing techniques which often require hand drawn masks. Nonetheless, pre-existing works struggle to take advantage of the natural instance-level compositionality of scenes due to the typically flat nature of rasterized RGB output images. Towards adressing this challenge, we introduce MuLAn: a novel dataset comprising over 44K MUlti-Layer ANnotations of RGB images as multilayer, instance-wise RGBA decompositions, and over 100K instance images. To build MuLAn, we developed a training free pipeline which decomposes a monocular RGB image into a stack of RGBA layers comprising of background and isolated instances. We achieve this through the use of pretrained general-purpose models, and by developing three modules: image decomposition for instance discovery and extraction, instance completion to reconstruct occluded areas, and image re-assembly. We use our pipeline to create MuLAn-COCO and MuLAn-LAION datasets, which contain a variety of image decompositions in terms of style, composition and complexity. With MuLAn, we provide the first photorealistic resource providing instance decomposition and occlusion information for high quality images, opening up new avenues for text-to-image generative AI research. With this, we aim to encourage the development of novel generation and editing technology, in particular layer-wise solutions. MuLAn data resources are available at https://MuLAn-dataset.github.io/., Comment: CVPR 2024 - Project page: https://MuLAn-dataset.github.io/
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- 2024
42. Fusion Dynamical Systems with Machine Learning in Imitation Learning: A Comprehensive Overview
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Hu, Yingbai, Abu-Dakka, Fares J., Chen, Fei, Luo, Xiao, Li, Zheng, Knoll, Alois, and Ding, Weiping
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Computer Science - Robotics - Abstract
Imitation Learning (IL), also referred to as Learning from Demonstration (LfD), holds significant promise for capturing expert motor skills through efficient imitation, facilitating adept navigation of complex scenarios. A persistent challenge in IL lies in extending generalization from historical demonstrations, enabling the acquisition of new skills without re-teaching. Dynamical system-based IL (DSIL) emerges as a significant subset of IL methodologies, offering the ability to learn trajectories via movement primitives and policy learning based on experiential abstraction. This paper emphasizes the fusion of theoretical paradigms, integrating control theory principles inherent in dynamical systems into IL. This integration notably enhances robustness, adaptability, and convergence in the face of novel scenarios. This survey aims to present a comprehensive overview of DSIL methods, spanning from classical approaches to recent advanced approaches. We categorize DSIL into autonomous dynamical systems and non-autonomous dynamical systems, surveying traditional IL methods with low-dimensional input and advanced deep IL methods with high-dimensional input. Additionally, we present and analyze three main stability methods for IL: Lyapunov stability, contraction theory, and diffeomorphism mapping. Our exploration also extends to popular policy improvement methods for DSIL, encompassing reinforcement learning, deep reinforcement learning, and evolutionary strategies.
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- 2024
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43. A Comprehensive Review on the Processing of Dried Fish and the Associated Chemical and Nutritional Changes
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Nursyah Fitri, Sharon Xi Ying Chan, Noor Hanini Che Lah, Faidruz Azura Jam, Norazlan Mohmad Misnan, Nurkhalida Kamal, Murni Nazira Sarian, Mohd Aizuddin Mohd Lazaldin, Chen Fei Low, Hamizah Shahirah Hamezah, Emelda Rosseleena Rohani, Ahmed Mediani, and Faridah Abas
- Subjects
fish ,drying ,nutritional compositions ,omics ,sensory attributes ,microorganisms ,Chemical technology ,TP1-1185 - Abstract
Fish is a good source of nutrients, although it is easily spoiled. As such, drying is a common method of preserving fish to compensate for its perishability. Dried fish exists in different cultures with varying types of fish used and drying methods. These delicacies are not only consumed for their convenience and for their health benefits, as discussed in this review. Most commonly, salt and spices are added to dried fish to enhance the flavours and to decrease the water activity (aw) of the fish, which further aids the drying process. For fish to be dried effectively, the temperature, drying environment, and time need to be considered along with the butchering method used on the raw fish prior to drying. Considering the various contributing factors, several physicochemical and biochemical changes will certainly occur in the fish. In this review, the pH, water activity (aw), lipid oxidation, and colour changes in fish drying are discussed as well as the proximate composition of dried fish. With these characteristic changes in dried fish, the sensory, microbial and safety aspects of dried fish are also affected, revolving around the preferences of consumers and their health concerns, especially based on how drying is efficient in eliminating/reducing harmful microbes from the fish. Interestingly, several studies have focused on upscaling the efficiency of dried fish production to generate a safer line of dried fish products with less effort and time. An exploratory approach of the published literature was conducted to achieve the purpose of this review. This evaluation gathers important information from all available library databases from 1990 to 2022. In general, this review will benefit the fishery and food industry by enabling them to enhance the efficiency and safety of fish drying, hence minimising food waste without compromising the quality and nutritional values of dried fish.
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- 2022
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44. Comparison of Different Dietary Fatty Acids Supplement on the Immune Response of Hybrid Grouper (Epinephelus fuscoguttatus × Epinephelus lanceolatus) Challenged with Vibrio vulnificus
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Maya Erna Natnan, Chen Fei Low, Chou Min Chong, Nur Iwani Nasuha Akiko Ahmad Daud, Ahmad Daud Om, and Syarul Nataqain Baharum
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oleic acid ,fish immunity ,immunology assay ,aquafeed supplementation ,vibriosis ,Biology (General) ,QH301-705.5 - Abstract
Aquaculture has been expanding in Malaysia due to the increased demand for fish products. In addition, aquaculture faces challenges in maintaining feed suitability in support of the global growth of fish production. Therefore, improvements in diet formulation are necessary to achieve the optimal requirements and attain a desirable growth efficiency and health performance in fish. Seven weeks of study were conducted to compare the equal amounts of different fatty acids (2%) (oleic acid, stearic acid, palmitic acid, and behenic acid) on the survival, the growth, and the immune response of hybrid grouper (Epinephelus fuscoguttatus × Epinephelus lanceolatus) against V. vulnificus. After six weeks of the feeding trial, fish were challenged with V. vulnificus for 30 min before continuing on the same feeding regime for the next seven days (post-bacterial challenge). Fish supplemented with dietary oleic acid showed significantly (p < 0.05) enhanced immune responses, i.e., lysozyme, respiratory burst, and phagocytic activities compared to the control diet group for both pre-and post-bacterial challenges. Following the Vibrio challenge, no significant effects of supplemented fatty acid diets on survival rate were observed, although dietary oleic acid demonstrated the highest 63.3% survival rate compared to only 43.3% of the control diet group. In addition, there were no significant effects (p > 0.05) on specific growth rate (SGR), white blood cell (WBC), and red blood cell (RBC) counts among all experimental diets. The results from this study suggest that among the tested dietary fatty acids, the oleic acid diet showed promising results in the form of elevated immune responses and increased disease resistance of the hybrid grouper fingerlings challenged with V. vulnificus.
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- 2022
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45. Risk Factors of Postoperative Recurrence for Giant Cell Tumor of Bone
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WU Zhaoyang, HUANG Linshan, WANG Shenglin, SHEN Rongkai, CHEN Fei, LIN Jianhua, and ZHU Xia
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giant cell tumor of bone ,postoperative recurrence ,cause analysis ,surgical treatment ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Objective To investigate the relationship between the characteristics and postoperative recurrence of giant cell tumor (GCT) of bone. Methods A total of 451 patients followed up with GCT of bone undergoing surgical treatment were reviewed to analyze the association of the characteristics, including tumor location, operation method, Campanacci grade, pathological fracture and pulmonary metastasis, with the recurrence rate of GCT bone. Results The recurrence rate of GCT in the spine or pelvis was significantly higher than that around the knee (P < 0.001), in distal radius (P=0.005) and in other parts (P < 0.001). The recurrence rate of grade Ⅲ GCT after simple excochleation was significantly higher than that after enlarged excochleation (P < 0.001) and tumor segment or block resection (P=0.002). The recurrence rate of GCT undergoing simple excochleation among cases of Campanacci gradeⅠ, Ⅱ and Ⅲ was significantly different (P=0.028); however, for GCT undergoing enlarged excochleation and tumor segment or block resection, there was no statistically significant difference of the recurrence rate between cases of gradeⅡ and Ⅲ (P > 0.05). The pulmonary metastasis rate in the recurrence cases of GCT was significantly higher than that in no recurrence cases (P < 0.001). There was no statistically significant difference of the recurrence rate of GCT between cases with and without pathological fracture (P > 0.05). Conclusion The surgical procedure affects the surgical boundary of GCT, which is closely related to the postoperative recurrence rate; the pulmonary metastasis rate of recurrent cases is significantly increased; adequate surgical boundaries for the surgical treatment of GCT may be essential to improve the prognosis of patients with GCT.
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- 2019
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46. Accelerating Diffusion Sampling with Optimized Time Steps
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Xue, Shuchen, Liu, Zhaoqiang, Chen, Fei, Zhang, Shifeng, Hu, Tianyang, Xie, Enze, and Li, Zhenguo
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Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Artificial Intelligence ,Computer Science - Machine Learning - Abstract
Diffusion probabilistic models (DPMs) have shown remarkable performance in high-resolution image synthesis, but their sampling efficiency is still to be desired due to the typically large number of sampling steps. Recent advancements in high-order numerical ODE solvers for DPMs have enabled the generation of high-quality images with much fewer sampling steps. While this is a significant development, most sampling methods still employ uniform time steps, which is not optimal when using a small number of steps. To address this issue, we propose a general framework for designing an optimization problem that seeks more appropriate time steps for a specific numerical ODE solver for DPMs. This optimization problem aims to minimize the distance between the ground-truth solution to the ODE and an approximate solution corresponding to the numerical solver. It can be efficiently solved using the constrained trust region method, taking less than $15$ seconds. Our extensive experiments on both unconditional and conditional sampling using pixel- and latent-space DPMs demonstrate that, when combined with the state-of-the-art sampling method UniPC, our optimized time steps significantly improve image generation performance in terms of FID scores for datasets such as CIFAR-10 and ImageNet, compared to using uniform time steps., Comment: CVPR 2024
- Published
- 2024
47. TAnet: A New Temporal Attention Network for EEG-based Auditory Spatial Attention Decoding with a Short Decision Window
- Author
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Ding, Yuting and Chen, Fei
- Subjects
Electrical Engineering and Systems Science - Signal Processing ,Computer Science - Machine Learning - Abstract
Auditory spatial attention detection (ASAD) is used to determine the direction of a listener's attention to a speaker by analyzing her/his electroencephalographic (EEG) signals. This study aimed to further improve the performance of ASAD with a short decision window (i.e., <1 s) rather than with long decision windows ranging from 1 to 5 seconds in previous studies. An end-to-end temporal attention network (i.e., TAnet) was introduced in this work. TAnet employs a multi-head attention (MHA) mechanism, which can more effectively capture the interactions among time steps in collected EEG signals and efficiently assign corresponding weights to those EEG time steps. Experiments demonstrated that, compared with the CNN-based method and recent ASAD methods, TAnet provided improved decoding performance in the KUL dataset, with decoding accuracies of 92.4% (decision window 0.1 s), 94.9% (0.25 s), 95.1% (0.3 s), 95.4% (0.4 s), and 95.5% (0.5 s) with short decision windows (i.e., <1 s). As a new ASAD model with a short decision window, TAnet can potentially facilitate the design of EEG-controlled intelligent hearing aids and sound recognition systems.
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- 2024
48. RHDLPP: A multigroup radiation hydrodynamics code for laser-produced plasmas
- Author
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Min, Qi, Xu, Ziyang, He, Siqi, Lu, Haidong, Liu, Xingbang, Shen, Ruizi, Wu, Yanhong, Pan, Qikun, Zhao, Chongxiao, Chen, Fei, Su, Maogen, and Dong, Chenzhong
- Subjects
Physics - Plasma Physics ,Physics - Atomic Physics ,Physics - Computational Physics ,Physics - Fluid Dynamics ,Physics - Optics - Abstract
We introduce the RHDLPP, a flux-limited multigroup radiation hydrodynamics numerical code designed for simulating laser-produced plasmas in diverse environments. The code bifurcates into two packages: RHDLPP-LTP for low-temperature plasmas generated by moderate-intensity nanosecond lasers, and RHDLPP-HTP for high-temperature, high-density plasmas formed by high-intensity laser pulses. The core radiation hydrodynamic equations are resolved in the Eulerian frame, employing an operator-split method. This method decomposes the solution into two substeps: first, the explicit resolution of the hyperbolic subsystems integrating radiation and fluid dynamics, and second, the implicit treatment of the parabolic part comprising stiff radiation diffusion, heat conduction, and energy exchange. Laser propagation and energy deposition are modeled through a hybrid approach, combining geometrical optics ray-tracing in sub-critical plasma regions with a one-dimensional solution of the Helmholtz wave equation in super-critical areas. The thermodynamic states are ascertained using an equation of state, based on either the real gas approximation or the quotidian equation of state (QEOS). Additionally, RHDLPP includes RHDLPP-SpeIma3D, a three-dimensional spectral simulation post-processing module, for generating both temporally-spatially resolved and time-integrated spectra and imaging, facilitating direct comparisons with experimental data. The paper showcases a series of verification tests to establish the code's accuracy and efficiency, followed by application cases, including simulations of laser-produced aluminum (Al) plasmas, pre-pulse-induced target deformation of tin (Sn) microdroplets relevant to extreme ultraviolet lithography light sources, and varied imaging and spectroscopic simulations.
- Published
- 2024
49. Deep Vein Thrombosis in the Uninjured Lower Extremity: A Retrospective Study of 1454 Patients With Lower Extremity Fractures
- Author
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Shuang-Wei Qu MD, Yu-Xuan Cong MD, Peng-Fei Wang MD, Chen Fei MD, Zhi Li MD, Kun Yang MD, Kun Shang MD, Chao Ke MM, Hai Huang MM, Yan Zhuang MD, Bin-Fei Zhang MD, and Kun Zhang MD
- Subjects
Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
The purpose of this study was to identify patients at higher risk of deep venous thrombosis (DVT) in the uninjured lower extremity both preoperatively and postoperatively in patients with lower extremity fractures. We collected the clinical data of patients with lower extremities fractures who presented at Xi’an Honghui Hospital between 1 July, 2015 and 31 October, 2017. Doppler ultrasonography was used to diagnose the DVT. Patients were examined pre- and postoperatively. The patients were divided into thrombosis group and no thrombosis group according to the preoperative and postoperative ultrasonography results. The thrombosis group was defined as patients with DVT in the uninjured lower extremity and the no thrombosis group was defined as patients without DVT in the uninjured lower extremity. This study enrolled 1454 patients who met the inclusion criteria. The incidence of preoperative DVT in the uninjured lower extremity was 9.63% whereas the postoperative incidence was 20.29%. Age (OR = 0.965, 95 CI%: 0.954-0.977; P ≤ 0.001) and female (OR = 0.667, 95% CI: 0.451-0.986, P = 0.042) were independent risk factors for preoperative DVT in the uninjured lower extremity. Blood loss (OR = 0.997, 95 CI%: 0.995-1.000; P = 0.020), D-dimer level at admission (OR = 0.941, 95 CI%: 0.887-0.999; P = 0.045), and postoperative day 5 D-dimer level (OR = 0.889, 95 CI%: 0.819-0.965; P = 0.005), were independent risk factors for postoperative DVT in the uninjured lower extremity. For the patients with lower extremity fractures, age and female were associated with the preoperative DVT in the uninjured lower extremity. Blood loss, D-dimer at admission and postoperative day 5 D-dimer were associated with the postoperative DVT in the uninjured lower extremity.
- Published
- 2021
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50. Distributed Multi-Object Tracking Under Limited Field of View Heterogeneous Sensors with Density Clustering
- Author
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Chen, Fei, Van Nguyen, Hoa, Leong, Alex S., Panicker, Sabita, Baker, Robin, and Ranasinghe, Damith C.
- Subjects
Computer Science - Multiagent Systems ,Electrical Engineering and Systems Science - Signal Processing - Abstract
We consider the problem of tracking multiple, unknown, and time-varying numbers of objects using a distributed network of heterogeneous sensors. In an effort to derive a formulation for practical settings, we consider limited and unknown sensor field-of-views (FoVs), sensors with limited local computational resources and communication channel capacity. The resulting distributed multi-object tracking algorithm involves solving an NP-hard multidimensional assignment problem either optimally for small-size problems or sub-optimally for general practical problems. For general problems, we propose an efficient distributed multi-object tracking algorithm that performs track-to-track fusion using a clustering-based analysis of the state space transformed into a density space to mitigate the complexity of the assignment problem. The proposed algorithm can more efficiently group local track estimates for fusion than existing approaches. To ensure we achieve globally consistent identities for tracks across a network of nodes as objects move between FoVs, we develop a graph-based algorithm to achieve label consensus and minimise track segmentation. Numerical experiments with a synthetic and a real-world trajectory dataset demonstrate that our proposed method is significantly more computationally efficient than state-of-the-art solutions, achieving similar tracking accuracy and bandwidth requirements but with improved label consistency.
- Published
- 2023
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