169 results on '"An, Qingxian"'
Search Results
2. Boosting All‐Perovskite Tandem Solar Cells by Revitalizing the Buried Tin‐Lead Perovskite Interface.
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Li, Guang, Wang, Chen, Fu, Shiqiang, Zheng, Wenwen, Shen, Weicheng, Jia, Peng, Huang, Lishuai, Zhou, Shun, Zhou, Jin, Wang, Cheng, Guan, Hongling, Zhou, Yuan, Zhang, Xuhao, Pu, Dexin, Fang, Hongyi, Lin, Qingxian, Ai, Wei, Chen, Weiqing, Zeng, Guojun, and Wang, Ti
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- 2024
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3. Dynamic event‐triggered orbit coordination for spacecraft formation via a self‐learning sliding mode control approach.
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Jia, Qingxian, Gao, Junnan, Wu, Yunhua, Liao, He, Zhang, Chengxi, and Wu, Jin
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SLIDING mode control , *AUTODIDACTICISM , *ORBITS (Astronomy) , *MACHINE learning , *ARTIFICIAL satellite attitude control systems - Abstract
Summary: This article investigates the issue of orbit coordination control for a class of multi‐spacecraft formation systems in presence of limited communication and external disturbance. To solve the limitation of communication sources, a dynamic event trigger (DET) mechanism is developed to reduce the communication frequency between the follower spacecrafts. Subsequently, we explore a robust DET mechanism‐based distributed self‐learning sliding mode control design, in which a variable learning intensity‐based iterative learning algorithm is designed to approximate and compensate space perturbation. This approach can guarantee an event triggering sequence without Zeno phenomenon and accurate coordination control for formation configuration simultaneously. Compared with the traditional event‐triggered control and other state‐of‐the‐art approaches, the distributed DET control scheme achieves higher control accuracy of formation configuration meanwhile requires less communication resource. Finally, a series of numerical simulations demonstrate the feasibility and superiority of the event triggered control method. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Circular RNA Gtdc1 Protects Against Offspring Osteoarthritis Induced by Prenatal Prednisone Exposure by Regulating SRSF1‐Fn1 Signaling.
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Liu, Liang, Hong, Yuntian, Ma, Chi, Zhang, Fan, Li, Qingxian, Li, Bin, He, Hangyuan, Zhu, Jiayong, Wang, Hui, and Chen, Liaobin
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CIRCULAR RNA ,PRENATAL exposure ,LOW birth weight ,CHONDROGENESIS ,LONG-distance running ,BIRTH weight ,OSTEOARTHRITIS ,ALTERNATIVE RNA splicing - Abstract
Chondrodysplasia is closely associated with low birth weight and increased susceptibility to osteoarthritis in adulthood. Prenatal prednisone exposure (PPE) can cause low birth weight; however, its effect on offspring cartilage development remains unexplored. Herein, rats are administered clinical doses of prednisone intragastrically on gestational days (GDs) 0–20 and underwent long‐distance running during postnatal weeks (PWs) 24–28. Knee cartilage is assayed for quality and related index changes on GD20, PW12, and PW28. In vitro experiments are performed to elucidate the mechanism. PPE decreased cartilage proliferation and matrix synthesis, causing offspring chondrodysplasia. Following long‐distance running, the PPE group exhibited more typical osteoarthritis‐like changes. Molecular analysis revealed that PPE caused cartilage circRNomics imbalance in which circGtdc1 decreased most significantly and persisted postnatally. Mechanistically, prednisolone reduced circGtdc1 expression and binding with Srsf1 to promote degradation of Srsf1 via K48‐linked polyubiquitination. This further inhibited the formation of EDA/B+Fn1 and activation of PI3K/AKT and TGFβ pathways, reducing chondrocyte proliferation and matrix synthesis. Finally, intra‐articular injection of offspring with AAV‐circGtdc1 ameliorated PPE‐induced chondrodysplasia, but this effect is reversed by Srsf1 knockout. Altogether, this study confirms that PPE causes chondrodysplasia and susceptibility to osteoarthritis by altering the circGtdc1‐Srsf1‐Fn1 axis; in vivo, overexpression of circGtdc1 can represent an effective intervention target for ameliorating PPE‐induced chondrodysplasia. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Association of carotid intima‐media thickness with periodontitis may depend on glycemic control.
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Yang, Hong, Cao, Pei, Wang, Xiaoxia, Xu, Xiao, Yang, Yifan, Xue, Fei, Luan, Qingxian, and Guo, Lixin
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RISK assessment ,CROSS-sectional method ,RESEARCH funding ,GLYCEMIC control ,MULTIPLE regression analysis ,CLINICAL pathology ,CAROTID intima-media thickness ,TYPE 2 diabetes ,CORONARY artery disease ,PERIODONTITIS ,DISEASE risk factors - Abstract
Background: There is evidence indicating that atherosclerosis is associated with periodontitis, especially in those with diabetes. The purpose of the present study was to determine whether glycemic control influences such association. Methods: Cross‐sectional data on 214 patients diagnosed with type 2 diabetes mellitus were obtained including results of basic laboratory tests, a periodontal examination, and carotid measurements. The association of periodontal parameters and carotid intima‐media thickness (cIMT) or carotid plaque (CP) was evaluated in subgroups. Results: Mean cIMT was significantly correlated with mean PLI, mean BI or number of PD ≥4 mm in the whole sample and the group with poor glycemic control. In the group with good glycemic control, however, only the number of PD ≥4 mm was associated with mean cIMT. A multiple logistic regression analysis also revealed that each 1 increase in mean PLI, mean BI or number of PD ≥4 mm was correlated with an increased cIMT in the whole sample. Conclusions: In addition to confirming the relationship between periodontitis and atherosclerosis, our study found a stronger association in groups with poor glycemic control compared to those with good glycemic control, suggesting that blood glucose modifies the association between periodontitis and arterial injury. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Bilateral extended FDK: An improved weighting method for static CT imaging.
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Zha, Keyang, Zhao, Qingxian, Luo, Shouhua, and Li, Yunxiang
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COMPUTED tomography , *CONE beam computed tomography , *BLOOD vessels , *DETECTORS , *RADIATION doses , *IMAGE reconstruction - Abstract
Background: Improving imaging speed has always been the focus of research in CT technology, which is related to the radiation dose and imaging quality of moving organs, including heart and blood vessels. However, it is difficult to achieve further improvement by increasing the rotation speed of the gantry due to its structural strength limitation. Differing from the conventional CTs, the static CT employs dozens of ray sources to acquire projection data from different angular ranges, and each source only needs to be rotated in a small range to finish a full 360° scan, thus greatly increasing the scanning speed. Purpose: As sources of static CT need to be evenly distributed over 360°, the sources and detectors have to be arranged on two parallel rings independently. Such a geometry can be considered as a special case of CT systems with a significantly large cone angle, that is, a part of the detector is missing in the vicinity of the mid‐plane. Due to restriction of upper and lower bounds of the cone angle of the static CT, there are uneven projection data varying in each portion of the reconstruction volume, the conventional analytical or iterative reconstruction methods may introduce artifacts in the reconstructed outcomes. Methods: Following the weighting approach extended FDK (xFDK) by Grimmer et al., we propose an improved bilateral xFDK algorithm (bixFDK), which focuses on the reconstruction of the expanded volume. With the same philosophy as xFDK in terms of weighting function design, bixFDK takes the longitudinal offset of the detector with respect to the source into consideration, making our method applicable to a wide range of CT geometries, especially for the static CT. Based on the proposed bixFDK, a new iterative scheme bixFDK‐IR is also constructed to extend the applications to a wide range of scan protocols such as sparse‐view scan. Results: The proposed method has been validated with the simulated phantom data and the actual clinical data of the static CT, and demonstrates that it can ensure good image quality and enlarge the reconstruction volume in z‐direction of the static CT. Conclusions: The bixFDK algorithm is an ideal reconstruction approach for static CT geometry, and the iterative scheme of bixFDK‐IR is applicable to a wide range of CT geometries and scan protocols, thus providing a wide range of application scenarios. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Regulatory B cells induced by interleukin‐35 inhibit inflammation and alveolar bone resorption in ligature‐induced periodontitis.
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Li, Shiyi, Su, Li, Luan, Qingxian, Liu, Guojing, Zeng, Wenmin, and Yu, Xiaoqian
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Background: Regulatory B cells (Bregs) have been reported to suppress immune responses and alveolar bone loss in murine periodontitis models. These cells could be induced by interleukin (IL)‐35 which is increased upon periodontal inflammation. Thus, this study aimed to explore the role of Bregs induced by IL‐35 in periodontitis. Methods: Experimental periodontitis was induced in mice by ligature. Two weeks after ligation, the test group was systemically treated with IL‐35 for 1 week. Four weeks after ligation, all mice were euthanized, and alveolar bone loss was evaluated by microcomputed tomography. Cytokines associated with periodontitis were analyzed using reverse transcription‐quantitative polymerase chain reaction and enzyme‐linked immunosorbent assay. Bregs in spleens, cervical lymph nodes, and periodontal tissues were detected by flow cytometry and immunofluorescence staining. Results: In the mouse model of periodontitis, IL‐35 induced the expansion of CD1dhiCD5+ B10 cells with increased interleukin‐10 (IL‐10) and IL‐35 production. IL‐35 administration also attenuated alveolar bone loss and reduced the levels of proinflammatory cytokines in situ. Conclusions: Following ligature‐induced periodontitis in mice, IL‐35 inhibited periodontal inflammation and alveolar bone resorption at least partially through the induction of B10 cells and IL‐35+ Bregs. [ABSTRACT FROM AUTHOR]
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- 2023
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8. A Supported Catalyst that Enables the Synthesis of Colorless CO2‐Polyols with Ultra‐Low Molecular Weight.
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Kuang, Qingxian, Zhang, Ruoyu, Zhou, Zhenzhen, Liao, Can, Liu, Shunjie, Chen, Xuesi, and Wang, Xianhong
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MOLECULAR weights , *POLYOLS , *CATALYSTS , *TELOMERIZATION , *URETHANE foam , *HYDROXYL group , *POLYMERS , *FOAM , *HETEROGENEOUS catalysts - Abstract
Ultra‐low molecular weight (ULMW) CO2‐polyols with well‐defined hydroxyl end groups represent useful soft segments for the preparation of high‐performance polyurethane foams. However, owing to the poor proton tolerance of catalysts towards CO2/epoxide telomerization, it remains challenging to synthesize ULMW yet colorless CO2‐polyols. Herein, we propose an immobilization strategy of constructing supported catalysts by chemical anchoring of aluminum porphyrin on Merrifield resin. The resulting supported catalyst displays both extremely high proton tolerance (≈8000 times the equivalents of metal centers) and independence of cocatalyst, affording CO2‐polyols with ULMW (580 g mol−1) and high polymer selectivity (>99 %). Moreover, the ULMW CO2‐polyols with various architectures (tri‐, quadra‐, and hexa‐arm) can be obtained, suggesting the wide proton universality of supported catalysts. Notably, benefiting from the heterogeneous nature of the supported catalyst, colorless products can be facilely achieved by simple filtration. The present strategy provides a platform for the synthesis of colorless ULMW polyols derived from not only CO2/epoxides, but also lactone, anhydrides etc. or their combinations. [ABSTRACT FROM AUTHOR]
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- 2023
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9. Deep sequencing of circulating miRNAs and target mRNAs level in deep venous thrombosis patients.
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Wang, Qingxian, Chang, Yunhe, Yang, Xuqing, and Han, Ziwang
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VENOUS thrombosis ,PERIPHERAL vascular diseases ,MICRORNA ,GENE expression ,RNA sequencing - Abstract
Deep venous thrombosis is one of the most common peripheral vascular diseases that lead to major morbidity and mortality. The authors aimed to identify potential differentially expressed miRNAs and target mRNAs, which were helpful in understanding the potential molecule mechanism of deep venous thrombosis. The plasma samples of patients with deep venous thrombosis were obtained for the RNA sequencing. Differentially expressed miRNAs were identified, followed by miRNA‐mRNA target analysis. Enrichment analysis was used to analyze the potential biological function of target mRNAs. GSE19151 and GSE173461 datasets were used for expression validation of mRNAs and miRNAs. 131 target mRNAs of 21 differentially expressed miRNAs were identified. Among which, 8 differentially expressed miRNAs including hsa‐miR‐150‐5p, hsa‐miR‐326, hsa‐miR‐144‐3p, hsa‐miR‐199a‐5p, hsa‐miR‐199b‐5p, hsa‐miR‐125a‐5p, hsa‐let‐7e‐5p and hsa‐miR‐381‐3p and their target mRNAs (PRKCA, SP1, TP53, SLC27A4, PDE1B, EPHB3, IRS1, HIF1A, MTUS1 and ZNF652) were found associated with deep venous thrombosis for the first time. Interestingly, PDE1B and IRS1 had a potential diagnostic value for patients. Additionally, 3 important signaling pathways including p53, PI3K‐Akt and MAPK were identified in the enrichment analysis of target mRNAs (TP53, PRKCA and IRS1). Identified circulating miRNAs and target mRNAs and related signaling pathways may be involved in the process of deep venous thrombosis. [ABSTRACT FROM AUTHOR]
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- 2023
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10. Robust actuator fault reconstruction for Takagi‐Sugeno fuzzy systems with unknown input via a synthesized learning and sliding‐mode observer.
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Jia, Qingxian, Li, Huayi, and Li, Min
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FUZZY systems ,ADAPTIVE fuzzy control ,LINEAR matrix inequalities ,ACTUATORS ,MATHEMATICAL optimization ,COORDINATE transformations - Abstract
The issue of robust actuator fault reconstruction for a class of Takagi‐Sugeno (T‐S) fuzzy systems with actuator fault and unknown input via a novel Synthesized Learning and Sliding‐Mode Observer (SLSMO) is investigated in this paper. Through a coordinate transformation technique, the considered T‐S fuzzy system is decomposed into two separate subsystems: Subsystem 1 affected only by actuator fault and Subsystem 2 affected by unknown input and actuator fault. In the SLSMO methodology, for Subsystem 1, a new reduced‐order Fuzzy Learning Observer (FLO) is explored to accurately reconstruct actuator fault, while a reduced‐order Fuzzy Sliding Mode Observer (FSMO) is employed for Subsystem 2 such that it has strong robustness against actuator fault and unknown input. Stability and convergence of the fuzzy SLSMO are explicitly proved using Lyapunov's indirect method. The design issue of the reduced‐order FLO and of the reduced‐order FSMO can be uniformly formulated in terms of some Linear Matrix Inequalities (LMIs) that can be directly solved using LMI optimization technique. In addition, a new full‐order FLO is suggested for actuator fault reconstruction in a class of T‐S fuzzy system without unknown input. At the end, a numerical example is applied to verify the effectiveness and superiority of the proposed approaches. [ABSTRACT FROM AUTHOR]
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- 2023
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11. Oxidative stress in human gingival fibroblasts from periodontitis versus healthy counterparts.
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Liu, Jia, Wang, Xiaoxuan, Zheng, Ming, and Luan, Qingxian
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CYTOKINES ,LIPOPOLYSACCHARIDES ,IN vitro studies ,INTERLEUKINS ,FIBROBLASTS ,BIOPSY ,PERIODONTITIS ,INFLAMMATION ,CHRONIC diseases ,WESTERN immunoblotting ,GRAM-negative anaerobic bacteria ,OXIDATIVE stress ,GENE expression ,MITOCHONDRIA ,FLUORESCENT antibody technique ,TUMOR necrosis factors ,ENZYME-linked immunosorbent assay ,RESEARCH funding ,REACTIVE oxygen species ,GINGIVA - Abstract
Objective: Elevated p53 promotes oxidative stress and production of pro‐inflammatory cytokines in liposaccharide (LPS)‐treated healthy human gingival fibroblasts (HGFs). This study compared oxidative stress, production of inflammatory cytokines, and p53 expression in HGFs from patients with chronic periodontitis (CP) and healthy subjects in vitro upon LPS from Porphyromonas gingivalis challenge. Methods: Human gingival fibroblasts were isolated from 6 biopsies—3 from healthy donors and 3 from diseased area in CP (Grade B, Stage III). HGFs were cultured with or without 1 μg/ml 24 h LPS. Oxidative stress was assessed by analyzing the level of reactive oxygen species (ROS). Mitochondrial membrane potential and respiration were determined by immunofluorescence and respirometry, respectively. Tumor necrosis factor (TNF)‐α, interleukin (IL)‐6, and IL‐1β were determined by enzyme‐linked immunosorbent assay. P53 expression was monitored by Western blot and immunofluorescence. Results: Human gingival fibroblasts from CP exhibited increased levels of mitochondrial p53, enhanced ROS production, decreased mitochondrial membrane potential, increased mitochondrial oxygen consumption, and increased secretion of TNF‐α, IL‐6, and IL‐1β, as compared to HGFs from healthy donors. Moreover, LPS exacerbated these changes. Conclusion: Human gingival fibroblasts from CP exhibited stronger basal and LPS‐inducible oxidative stress and inflammatory response as compared to HGFs from healthy subjects by increased p53 in mitochondria. [ABSTRACT FROM AUTHOR]
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- 2023
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12. Weak direct current exerts synergistic effect with antibiotics and reduces the antibiotic resistance: An in vitro subgingival plaque biofilm model.
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Peihui Zou, Yanfeng Wang, Pei Cao, Peng Li, Jia Liu, and Qingxian Luan
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IN vitro studies ,DENTAL plaque ,BIOFILMS ,DRUG resistance in microorganisms - Abstract
Background and Objective: Weak direct current (DC) exerts killing effect and synergistic killing effect with antibiotics in some specific bacteria biofilms. However, the potential of weak DC alone or combined with periodontal antibiotics in controlling periodontal pathogens and plaque biofilms remains unclear. The objective of this study was to investigate whether weak DC could exert the anti-biofilm effect or enhance the killing effect of metronidazole (MTZ) and/or amoxicillin–clavulanate potassium (AMC) on subgingival plaque biofilms, by constructing an in vitro subgingival plaque biofilm model. Methods: The pooled subgingival plaque and saliva of patients with periodontitis (n = 10) were collected and cultured anaerobically on hydroxyapatite disks in vitro for 48 h to construct the subgingival plaque biofilm model. Then such models were stimulated with 0 μA DC alone (20 min/12 h), 1000 μA DC alone (20 min/12 h), 16 μg/ ml MTZ, 16 μg/ml AMC or their combination, respectively. Through viable bacteria counting, metabolic activity assay, quantitative real-time PCR absolute quantification and 16S rDNA sequencing analysis, the anti-biofilm effect of 1000 μA DC and enhanced killing effects of 1000 μA DC combined with antibiotics (MTZ, AMC or MTZ+AMC) were explored. Results: The old subgingival plaque model (48 h) had no significant difference in total bacterial loads from subgingival plaque in situ, which achieved a similarity of 80%. The 1000 μA DC plus MTZ or AMC for 12 h showed a stronger synergistic killing effect than the same combination for 20 min. The metabolic activity was reduced to the lowest by DC plus MTZ+AMC, as 37.4% of that in the control group, while average synergistic killing effect reached 1.06 log units and average total bacterial loads decreased to 0.87 log units. Furthermore, the relative abundance of the genera Porphyromonas, Prevotella, Treponema_2, and Tannerella were decreased significantly. Conclusion: The presence of weak DC (1000 μA) improved the killing effect of antibiotics on subgingival plaque biofilms, which might provide a novel strategy to reduce their antibiotic resistance. [ABSTRACT FROM AUTHOR]
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- 2023
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13. Assessment of community‐managed blood glucose control in patients with diabetes mellitus in Shenzhen, China.
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Fang, Lihua, Li, Qingxian, and Ning, Jie
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BLOOD sugar , *DIABETES , *PEOPLE with diabetes , *HEALTH facilities , *BLOOD sugar monitoring , *HYPERGLYCEMIA - Abstract
This article discusses the assessment of community-managed blood glucose control in patients with diabetes mellitus in Shenzhen, China. The study conducted a follow-up investigation on 359 patients with type 2 diabetes and collected data on medication, blood glucose monitoring, glycated hemoglobin, body mass index, diet, and exercise habits over 6 months. The study found that 62.70% of patients met the standard for blood glucose control, and factors such as standardized management, medication selection, dietary patterns, and metformin dosage were significantly correlated with blood glucose control. The findings highlight the importance of standardized management, sensible diet, and reasonable medication in improving blood glucose control among community diabetic patients. The study also emphasizes the need for individualized treatment strategies and community health education to improve blood glucose control. [Extracted from the article]
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- 2024
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14. The impact of green finance on the level of decarbonization of the economies: An analysis of the United States', China's, and Russia's current agenda.
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Jia, Qingxian
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UNITED States economy ,CARBON dioxide mitigation ,BONDS (Finance) ,GREEN bonds ,CHINA-United States relations ,ENVIRONMENTAL protection ,GREEN roofs - Abstract
With growing global concern for mainstreaming of environmental protection measures, the promotion of climate change and sustainable development policies, the international community, represented by international organizations, research institutions, and world‐wide businesses, has focused on green finance. Existing research on green finance in the context of environmental trends has been reviewed in terms of the products and determinants of green finance. This study aims to assess the impact of green finance on the decarbonization of economies in the context of a review of current and potential problems and prospects. Based on the examples of the People's Republic of China, the Russian Federation, and the United States of America, the study suggests that today green finance has not yet demonstrated a tangible effect in these countries. Based on the results of the study, it can be argued that in the three countries, the main tool of green finance in the field of decarbonization is green bonds; other types of green finance are used to a limited extent. The progress of the United States and China is not so obvious, but based on the overall involvement of relevant government agencies and businesses in the green bond market, it can be assumed that the results will be observed in the near future. [ABSTRACT FROM AUTHOR]
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- 2023
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15. The accuracy evaluation method of baseline estimation algorithms in energy dispersive X‐ray fluorescence spectrum analysis.
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Jia, Luman, Gu, Yi, Zhang, Qingxian, Zhang, Jian, Yan, Xiaolan, Zhang, Yifan, Wang, Youjing, and Ge, Liangquan
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X-ray spectroscopy ,ENERGY dispersive X-ray spectroscopy ,FAST Fourier transforms ,MONTE Carlo method ,X-ray fluorescence ,EVALUATION methodology ,SPECTRUM analysis - Abstract
In energy dispersive X‐ray fluorescence analysis (EDXRF), many baseline estimation algorithms have been proposed for the accurate characteristic peak area. However, the true value of the characteristic peak area of measured spectrum is unknown and cannot be used to evaluate the accuracy of the baseline estimation algorithms. In this article, an assessment method was proposed based on Monte Carlo simulation, which can obtain the characteristic peak area, and evaluate the accuracy of the baseline estimation algorithms directly. Meanwhile, the accuracy and practicality of four baseline estimation algorithms were evaluated by the assessment method, which include statistics‐sensitive nonlinear iterative peak‐clipping (SINP), fast Fourier transform (FFT), adaptive iteratively reweighted penalized least squares (AirPLS), and automated iterative moving averaging (AIMA). Comparing the relative error of the characteristic peak area, AirPLS gave the best performance for baseline estimation in EDXRF. [ABSTRACT FROM AUTHOR]
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- 2023
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16. Effect of material parameters on thermal shock crack of ceramics calculated by phase‐field method.
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Zuo, Chuandong, Li, Qingxian, Wang, Qian, Li, Yuqiao, Li, Long, Wei, Jiachen, Shao, Yingfeng, and Song, Fan
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THERMAL shock , *THERMAL properties , *FRACTURE toughness , *YOUNG'S modulus , *CERAMICS , *CRACK propagation (Fracture mechanics) , *SPECIFIC heat - Abstract
Based on alumina ceramics, we employ the phase‐field method to study the effects of thermal conductivity, specific heat, density, thermal expansion coefficient, Young's modulus, and fracture toughness on thermal shock cracks. The results show that increasing thermal conductivity and fracture toughness will reduce thermal shock damage. That is, the long crack length becomes shorter, or the crack density becomes smaller. However, increasing the thermal expansion coefficient and Young's modulus will increase thermal shock damage. It is consistent with the previous thermal shock theory. The effect of material parameters on crack propagation speed was also considered. In addition, we carried out a thermal shock test of the zirconia. The results of the phase‐field calculation are the same as the thermal shock results of the zirconia. This paper verifies that the phase‐field method is suitable for simulating thermal shock cracks in other ceramics. [ABSTRACT FROM AUTHOR]
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- 2022
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17. Wear and fracture of curettes due to sharpening and scaling processes.
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Liu, Guojing, Liu, Xueling, Li, Na, Gao, Chengcheng, Cui, Ting, Luan, Qingxian, and Wang, Jianmin
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DENTAL equipment ,MEDICAL equipment reliability ,DENTAL plaque ,DENTAL scaling ,FISHER exact test ,T-test (Statistics) ,DESCRIPTIVE statistics ,DATA analysis software ,LOGISTIC regression analysis ,EQUIPMENT maintenance & repair ,PROPORTIONAL hazards models - Abstract
Objectives: To examine the wear occurring in a group of new Gracey curettes due to the sharpening and scaling processes and record the number of service cycles before breakage. Methods: This study included 592 working ends of Gracey curettes that were subjected to cycles of sharpening and scaling. Three‐dimensional measurements of the blades and the status of the working ends were recorded before and after each process. Results: With an increase in the number of usage cycles, the three‐dimensional measurements of the blades decreased. During this study, 184 working ends were broken, of which 38.59% were of #11/12 Gracey curettes, and only 8.15% were of #7/8 Gracey curettes. The average number of cycles required for the fracture of Gracey curettes was 14.34. Cox regression analyses showed that the factors influencing the survival cycles were the tip width before usage and the type of Gracey curette. Moreover, the sharpening process was responsible for approximately half of the total instrument wear. Among the four types of Gracey curettes, the #11/12 Gracey curettes showed the greatest amount of sharpening wear, accounting for >50% of the total wear. Conclusions: The service life of Gracey curettes varies according to their types; the #11/12 Gracey curettes are more susceptible to breakage, while #7/8 Gracey curettes tend to have a long service life. Furthermore, the sharpening process was responsible for a considerable amount of curette wear. [ABSTRACT FROM AUTHOR]
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- 2022
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18. Modified Double‐Row and Double‐Pulley Technique for the Treatment of Type Ia Scapular Glenoid Fractures.
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Wang, Yizhong, Li, Qingxian, and Zhang, Qingsong
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ARTHROSCOPY , *SHOULDER joint , *VENOUS thrombosis , *TOTAL shoulder replacement , *VISUAL analog scale , *FRACTURE healing , *COMPUTED tomography - Abstract
Objective: To evaluate the efficacy of the double‐row and double‐pulley technique in treating anterior shoulder glenoid fracture (Ideberg type Ia) using shoulder arthroscopy. Methods: Thirty‐six patients with Ideberg type Ia admitted from March 1, 2017, to March 1, 2020, were retrospectively reviewed. Data of the patients' history included age, sex, side of the affected arm, the mean time from injury to surgery, the surgical duration, the average blood loss, and the average total duration of hospital stay. The double‐row and double‐pulley technique was used to repair the scapular glenoid fracture under arthroscopy. Computed tomography (CT) was used to evaluate fracture healing after surgery. The American Shoulder and Elbow Surgeons (ASES) score, the University of California at Los Angeles (UCLA) shoulder joint scoring system, and the Constant–Murley shoulder function score were used to assess the function of the affected shoulder. Results: The surgical duration was 90–150 min, with a mean of 127 min. The average blood loss was 90 mL (range, 60–120 mL), and the average total duration of hospital stay was 9.2 days (range, 3 to 14 days). At 9 months after surgery, the CT results showed that all fractures healed, and all patients returned to their previous levels of activity and regained an excellent range of motion. The visual analog scale (VAS) score was 7.55 ± 1.32 before surgery, and the VAS score significantly decreased to 1.24 ± 0.72 at 12 months after the operation (p < 0.05). The Constant, ASES, and UCLA shoulder function scores were 44.38 ± 2.16, 43.47 ± 12.76, and 21.80 ± 1.16 before the surgery, respectively, which improved to 93.52 ± 2.82, 91.34 ± 8.28, and 33.24 ± 1.64, respectively, in the following 12 months. One patient experienced fat liquefaction. However, no cases of deep venous thrombosis, iatrogenic neurovascular compromise, wound infection, or neurovascular injury were identified. Conclusion: The double‐row and double‐pulley technique for treating Ideberg type Ia under shoulder arthroscopy has minor surgical trauma, reliable fracture reduction and fixation, less postoperative pain, and fewer postoperative complications and significantly improves the patient's shoulder joint function. [ABSTRACT FROM AUTHOR]
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- 2022
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19. Clinical and histological evaluation of the use of acellular dermal matrix (ADM) membrane in peri‐implant vertical soft tissue augmentation: A controlled clinical trial.
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Zang, Jing, Su, Li, Luan, Qingxian, Liu, Guojing, Li, Shiyi, and Yu, Xiaoqian
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EXTRACELLULAR matrix proteins ,HISTOLOGICAL techniques ,MEMBRANE transport proteins ,PERI-implantitis ,SOFT tissue injuries ,TRANSPLANTATION of organs, tissues, etc. ,CLINICAL trials - Abstract
Objectives: The aim of this study was to clinically and histologically evaluate the efficacy of using acellular dermal matrix (ADM) for peri‐implant vertical soft tissue augmentation at implant placement. Materials and methods: Twenty patients were enrolled in this study. According to the initial thickness of vertical soft tissue, patients were assigned into the ADM group (≤2 mm) or the control group (>2 mm) prior to implant surgery +ADM grafting or implant surgery alone. Second‐stage surgery was carried out 3 months later, and a small piece of ridge membrane was harvested for histological and immunohistochemical evaluation. Vascular endothelial growth factor (VEGF) and platelet‐derived growth factor (PDGF)‐BB in peri‐implant crevicular fluid (PICF) were also assessed 1 week, 1 month, and 5 months after second‐stage surgery. Clinical parameters were recorded to evaluate peri‐implant health at 1 week and 3 months after implant restoration. Results: All 20 implants healed uneventfully and successfully. Soft tissue thicknesses were comparable in the two groups at second‐stage surgery (3.20 ± 0.42 mm vs. 3.50 ± 0.58 mm). In the ADM group, the mean increase in soft tissue thickness was 1.85 ± 0.34 mm. Histological and immunohistochemical outcomes showed no differences between the two groups. VEGF and PDGF‐BB levels in PICF were significantly lower in the ADM group 1 week after second‐stage surgery (p <.01), yet they decreased in both groups later. The difference between the groups had disappeared by 5 months after second‐stage surgery. The clinical peri‐implant parameters were good and stable by the end of the study (3 months after restoration). Conclusions: Our results suggested that using ADM at implant placement was effective in increasing the thickness of peri‐implant vertical soft tissue and achieved comparable clinical and histological performance to the control group. However, the incremental soft tissue showed inferior angiogenic ability in the early stage of wound healing. [ABSTRACT FROM AUTHOR]
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- 2022
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20. Abnormal mitochondrial structure and function are retained in gingival tissues and human gingival fibroblasts from patients with chronic periodontitis.
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Liu, Jia, Wang, Xiaoxuan, Xue, Fei, Zheng, Ming, and Luan, Qingxian
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MITOCHONDRIAL pathology ,GINGIVA ,FIBROBLASTS ,PERIODONTITIS ,CHRONIC diseases ,CONNECTIVE tissues ,REVERSE transcriptase polymerase chain reaction ,WESTERN immunoblotting - Abstract
Background and Objective: The abnormal structure and function of mitochondria in cells is closely associated with inflammatory diseases. However, the physiology of mitochondria within gingival tissues and human gingival fibroblasts (HGFs) in patients with chronic periodontitis (CP) remains unclear. The objective of this study was to investigate the structure profile and function of mitochondria in gingival tissues and in HGFs derived from patients with or without CP. These features of mitochondria in HGFs were further analyzed when HGFs were induced by lipopolysaccharide (LPS) from Porphyromonas gingivalis (P.g). Methods: Gingival tissues and HGFs were collected from CP and healthy patients. Mitochondrial structure was assessed by transmission electron microscopy. Tissues or cells lysis was performed for mitochondrial DNA (mtDNA) quantification, and real‐time polymerase chain reaction (RT‐PCR) tests were used to determine mtDNA copy numbers. Western blot analysis was used to evaluate autophagy‐related protein (ATG)‐5, microtubule‐associated protein light chain 3 (LC3), and mitochondrial matrix protein pyruvate dehydrogenase kinase isozyme 2 (PDK2) levels in tissues and HGFs from CP and healthy individuals. Results: Tissues and HGFs from CP showed a significant greater mitochondrial structure destruction, lower mtDNA level, increased ATG5, LC3‐II, and lower PDK2 protein levels than those of healthy individuals. In addition, LPS from P.g also triggered the same results in HGFs from healthy donors. Moreover, the challenge of HGFs from CP with LPS worsened these parameters. Conclusion: Mitochondrial structure and function within gingival tissues and HGFs from CP individuals were abnormal compared to those from healthy donors, and LPS could promote mitochondrial destruction. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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21. Design and Optimization of SiOx/AZO Transparent Passivating Contacts for High‐Efficiency Crystalline Silicon Solar Cells.
- Author
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Cai, Haihuai, Zhong, Zhuotong, Nong, Qingxian, Gao, Pingqi, and He, Jian
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SILICON solar cells , *SOLAR cells , *SURFACE passivation , *ZINC oxide films , *SILICON oxide - Abstract
A highly transparent passivating contact (TPC) used for high‐efficiency crystalline silicon (c‐Si) solar cells should meet several key criteria: high optical transparency, excellent c‐Si surface passivation, low contact resistivity, and a low‐temperature fabrication process suitable for device integration. Here, a simple TPC is developed structure consisting of a silicon oxide (SiOx) tunneling passivating layer and an aluminum doped zinc oxide (AZO) electron‐selective transporting layer (SiOx/AZO). This TPC demonstrated remarkable passivation quality with a low contact recombination current density of below 2.2 fA cm−2, an implied open‐circuit voltage of close to 740 mV and a contact resistivity below 20 mΩ·cm2 when contact with lightly doped n‐type c‐Si. This excellent passivation performance can be attributed to improved interfacial hydrogen chemical passivation and the field‐effect passivation induced by the highly Al‐doped ZnO film. Demonstrated n‐type c‐Si solar cells using full‐area SiOx/AZO rear contacts achieved a significant efficiency of 23.17%. Further power loss analysis based on numerical simulations outlines the pathway to achieving efficiencies exceeding 26%. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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22. DEA‐based centralized resource allocation with network flows.
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Tao, Xiangyang, Xiong, Beibei, and An, Qingxian
- Subjects
RESOURCE allocation ,DATA envelopment analysis ,COST allocation ,CHARACTERISTIC functions - Abstract
This study investigates the centralized resource allocation problem among individual units using network flow theory in a data envelopment analysis (DEA) framework. Existing research on DEA‐based resource allocation is primarily concerned with the amount of allocated resources to individual units, and only a few studies have considered resource flows when resources are allocated. To identify the internal structure of the resource allocation process, network structure is introduced and network flow theory is used to search for the optimal resource allocation scheme. Moreover, resource allocation cost is considered in network flows and a resource allocation gain (RAG) function is formulated to provide a quantitative analysis of the trade‐off between production gains from resource allocation and resource allocation cost in the resource allocation process. In addition, several characteristics of the RAG function are also discussed. Lastly, the proposed method is demonstrated through an expository example with several random data and an application of the centralized resource reallocation to bank systems. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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- View/download PDF
23. Clinicopathological and immunological characterization of RNA m6A methylation regulators in ovarian cancer.
- Author
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Wang, Qingying, Zhang, Qinyi, Li, Qingxian, Zhang, Jing, and Zhang, Jiawen
- Subjects
OVARIAN cancer ,RNA methylation ,PACLITAXEL ,REGULATOR genes ,BIOMARKERS - Abstract
Background: N6‐methyladenosine (m6A) modification is one of the critical gene regulatory mechanisms implicated in cancer biology. However, the roles of m6A regulators in ovarian cancer are still poorly understood. Methods: We integrated multiple databases including Gene Expression Omnibus (GEO), ROC Plotter, Kaplan‐Meier Plotter, and Tumor Immune Estimation Resource (TIMER) to explore clinicopathological significance of m6A regulators in ovarian cancer. Results: We showed that alterations in the expression of m6A regulators were related to the malignancy and poor prognosis of ovarian cancer. We found decreased YTHDC1 and increased RBM15 expressions were associated with ovarian cancer cell metastases and HNRNPC was a predictor of paclitaxel resistance. Moreover, dysregulated m6A regulators were enriched in the activation of cancer‐related pathways. Our results further demonstrated that the level of immune cell infiltration and the expression of various immune gene markers were closely associated with the expressions of specific m6A regulators (RBM15B, ZC3H13, YTHDF1, and IGF2BP1). Conclusions: Our study establishes a new prognostic profile of ovarian cancer patients based on m6A regulators, and highlights the potential roles of m6A regulators in ovarian cancer development. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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24. Circ_0000105 promotes liver cancer by regulating miR‐498/PIK3R1.
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Sun, Yanni, Sun, Xiuxiang, and Huang, Qingxian
- Abstract
Background: A growing number of studies demonstrate that circular RNA (circRNA) has a prominent role in the regulation of numerous biological behaviors of tumor cells. The present study aimed to investigate the expression, function and molecular mechanisms of circ_0000105 in liver cancer. Methods: A quantitative real‐time polymerase chain reaction (qRT‐PCR) was utilized to obtain the expressions of circ_0000105 and miR‐498 in liver cancer tissues and cells. The association between the expression level of circ_0000105 and the clinicopathological characteristics of liver cancer patients was analyzed. qRT‐PCR and western blotting were utilized to investigate the expression of phosphoinositide‐3‐kinase regulatory subunit 1 (PIK3R1) in cells. Cell counting kit‐8, bromodeoxyuridine and flow cytometry assays were utilized to determine liver cancer cell proliferation and apoptosis, respectively. Bioinformatics, a luciferase reporter gene experiment and a RNA immunoprecipitation experiment were conducted to predict and confirm the targeting correlation of circ_0000105 and miR‐498, as well as miR‐498 and PIK3R1. Results: Circ_0000105 was highly expressed in liver cancer tissues and cell lines. Moreover, its high expression was associated with an increase in the T stage of liver cancer patients and a low degree of tumor differentiation. Circ_0000105 overexpression promoted liver cancer cell proliferation and inhibited apoptosis, whereas knocking down circ_0000105 triggered the opposite effect. miR‐498 was a downstream target of circ_0000105, inhibiting liver cancer cell proliferation and promoting apoptosis. Mechanistically, circ_0000105 indirectly up‐regulated the expression of PIK3R1 by adsorbing miR‐498. Conclusions: Circ_0000105 plays a cancer‐promoting role in liver cancer by regulating the miR‐498/PIK3R1 axis. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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25. Longitudinal changes of liver function and hepatitis B reactivation in COVID‐19 patients with pre‐existing chronic hepatitis B virus infection.
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Liu, Jiaye, Wang, Tingyan, Cai, Qingxian, Sun, Liqin, Huang, Deliang, Zhou, Guangde, He, Qing, Wang, Fu‐Sheng, Liu, Lei, and Chen, Jun
- Subjects
CHRONIC hepatitis B ,COVID-19 ,VIRUS diseases ,HEPATITIS B ,HEPATITIS B virus - Abstract
Aim: With the current coronavirus disease (COVID‐19) pandemic and high endemic levels of chronic hepatitis B virus (HBV) infection worldwide, it is urgent to investigate liver function changes of COVID‐19 patients with chronic HBV infection, and how severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection in turn affects the course of chronic HBV infection. Method: We undertook a retrospective study based on 347 COVID‐19 patients (21 vs. 326 with vs. without chronic HBV infection). With the propensity score matching (PSM) method, we yielded 20 and 51 matched patients for the HBV group and the non‐HBV group, respectively. Results: At the end of follow‐up, all of these 71 patients achieved SARS‐CoV‐2 clearance (P = 0.1). During the follow‐up, 30% versus 31.4% in the HBV group versus non‐HBV group progressed to severe COVID‐19 (P = 0.97). After PSM, the longitudinal changes of median values for liver biochemistries were not significantly different between the two groups. In the HBV group versus non‐HBV group, 35% (7/20) versus 37.25% (19/51) (P = 0.86) had abnormal alanine aminotransferase at least once during hospitalization, 30% (6/20) versus 31.37% (16/51) had abnormal aspartate aminotransferase (P = 0.91), 40% (8/20) versus 37.25% (19/51) had abnormal γ‐glutamyltransferase (P = 0.83), and 45% (9/20) versus 39.22% (20/51) had abnormal total bilirubin levels (P = 0.91). Moreover, three patients in the HBV group had hepatitis B reactivation. Conclusions: Liver dysfunction presented in COVID‐19 patients with/without chronic HBV. Moreover, those COVID‐19 patients co‐infected with chronic HBV could have a risk of hepatitis B reactivation. It is necessary to monitor liver function of COVID‐19 patients, as well as HBV‐DNA levels for those co‐infected with HBV during the whole disease course. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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26. COVID‐19 in a designated infectious diseases hospital outside Hubei Province, China.
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Cai, Qingxian, Huang, Deliang, Ou, Pengcheng, Yu, Hong, Zhu, Zhibin, Xia, Zhang, Su, Yinan, Ma, Zhenghua, Zhang, Yiming, Li, Zhiwei, He, Qing, Liu, Lei, Fu, Yang, and Chen, Jun
- Subjects
- *
COMMUNICABLE diseases , *COVID-19 , *SARS-CoV-2 , *MEDICAL care , *BLOOD sedimentation - Abstract
Background: The clinical characteristics of novel coronavirus disease (COVID‐2019) patients outside the epicenter of Hubei Province are less understood. Methods: We analyzed the epidemiological and clinical features of all COVID‐2019 cases in the only referral hospital in Shenzhen City, China, from January 11, 2020, to February 6, 2020, and followed until March 6, 2020. Results: Among the 298 confirmed cases, 233 (81.5%) had been to Hubei, while 42 (14%) did not have a clear travel history. Only 218 (73.15%) cases had a fever as the initial symptom. Compared with the nonsevere cases, severe cases were associated with older age, those with underlying diseases, and higher levels of C‐reactive protein, interleukin‐6, and erythrocyte sedimentation rate. Slower clearance of the virus was associated with a higher risk of progression to critical condition. As of March 6, 2020, 268 (89.9%) patients were discharged and the overall case fatality ratio was 1.0%. Conclusions: In a designated hospital outside Hubei Province, COVID‐2019 patients could be effectively managed by properly using the existing hospital system. Mortality may be lowered when cases are relatively mild, and there are sufficient medical resources to care and treat the disease. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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- View/download PDF
27. SPC25 may promote proliferation and metastasis of hepatocellular carcinoma via p53.
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Chen, Fengjuan, Zhang, Ka, Huang, Yilin, Luo, Fang, Hu, Kunpeng, and Cai, Qingxian
- Subjects
HEPATOCELLULAR carcinoma ,METASTASIS ,P53 antioncogene ,STATISTICAL correlation - Abstract
Hepatocellular carcinoma (HCC) is a common malignancy with poor prognosis and high mortality. To identify key genes associated with HCC and the underlying mechanisms, we performed weighted correlation network analysis (WGCNA) of potential key genes of HCC. We identified 17 key genes closely related to HCC by yellow module combined with PPI analysis. Verification of the role of these genes revealed that SPC25 knockdown results in a significant decrease in proliferation and metastasis of HCC cells and increased protein levels of components of the p53 pathway in vitro. In summary, we identified that SPC25 is a potential tumor‐promoting factor in HCC and may act via the p53 pathway. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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28. MeCP2 epigenetically regulates alpha‐smooth muscle actin in human lung fibroblasts.
- Author
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Xiang, Zheyi, Zhou, Qingxian, Hu, Min, and Sanders, Yan Y.
- Published
- 2020
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29. Highly Transparent and Flexible Iontronic Pressure Sensors Based on an Opaque to Transparent Transition.
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Liu, Qingxian, Liu, Zhiguang, Li, Chenggao, Xie, Kewei, Zhu, Pang, Shao, Biqi, Zhang, Jianming, Yang, Junlong, Zhang, Jin, Wang, Quan, and Guo, Chuan Fei
- Subjects
- *
PRESSURE sensors , *ELECTRIC double layer , *ELECTROCHROMIC windows , *POLYVINYLIDENE fluoride , *POROUS materials , *REFRACTIVE index - Abstract
Human–computer interfaces, smart glasses, touch screens, and some electronic skins require highly transparent and flexible pressure‐sensing elements. Flexible pressure sensors often apply a microstructured or porous active material to improve their sensitivity and response speed. However, the microstructures or small pores will result in high haze and low transparency of the device, and thus it is challenging to balance the sensitivity and transparency simultaneously in flexible pressure sensors or electronic skins. Here, for a capacitive‐type sensor that consists of a porous polyvinylidene fluoride (PVDF) film sandwiched between two transparent electrodes, the challenge is addressed by filling the pores with ionic liquid that has the same refractive index with PVDF, and the transmittance of the film dramatically boosts from 0 to 94.8% in the visible range. Apart from optical matching, the ionic liquid also significantly improves the signal intensity as well as the sensitivity due to the formation of an electric double layer at the dielectric‐electrode interfaces, and improves the toughness and stretchability of the active material benefiting from a plasticization effect. Such transparent and flexible sensors will be useful in smart windows, invisible bands, and so forth. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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30. Yap1 is required for maintenance of adult RPE differentiation.
- Author
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Lu, Qingxian, Scott, Patrick A., Vukmanic, Eric V., Kaplan, Henry J., Dean, Douglas C., and Li, Qiutang
- Abstract
Nuclear YAP1 plays a critical role in regulation of stem cell proliferation, tissue regeneration, and organ size in many types of epithelia. Due to rapid turnover of most epithelial cell types, the cytoplasmic function of YAP1 in epithelial cells has not been well studied. The retinal pigment epithelium (RPE) is a highly polarized epithelial cell type maintained at a senescence state, and offers an ideal cell model to study the active role of YAP1 in maintenance of the adult epithelial phenotype. Here, we show that the cytoplasmic function of YAP1 is essential to maintain adult RPE differentiation. Knockout of Yap1 in the adult mouse RPE caused cell depolarization and tight junction breakdown, and led to inhibition of RPE65 expression, diminishment of RPE pigments, and retraction of microvilli and basal infoldings. These changes in RPE further prompted the loss of adjacent photoreceptor outer segments and photoreceptor death, which eventually led to decline of visual function in older mice between 6 and 12 months of age. Furthermore, nuclear β‐catenin and its activity were significantly increased in mutant RPE. These results suggest that YAP1 plays an important role in active inhibition of Wnt/β‐catenin signaling, and is essential for downregulation of β‐catenin nuclear activity and prevention of dedifferentiation of adult RPE. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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- View/download PDF
31. Synthetic evaluation of DC power quality based on combination weighting.
- Author
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Li, Huixin, Yi, Benshun, Li, Qingxian, Ming, Jun, and Zhao, Zhigang
- Subjects
DIRECT current power transmission ,ANALYTIC hierarchy process ,ELECTRON tube grids ,SYNTHETIC apertures ,ELECTRICAL engineers - Abstract
With the development of global renewable energy, DC transmission and DC power distribution technology have been applied on a large scale, and the requirements for DC power quality (PQ) are more stringent. Evaluating DC PQ reasonably and effectively has become a research hotspot at this stage. In this paper, a comprehensive analysis for various indexes of DC PQ is conducted to obtain a unified parameter for describing the characteristics of PQ from an overall perspective. First, weight values of PQ indexes are calculated by combining fuzzy analytic hierarchy process (FAHP) and the improved entropy weight method. FAHP can satisfy the consistency without the consistency test, and the improved entropy weight method is an objective weighting method that can effectively avoid the preference of subjective weighting method. Then, based on a triangular fuzzy function, the membership degree is obtained. Finally, a fuzzy comprehensive evaluation is made. An example analysis is carried out with the data provided by the Gree photovoltaic direct‐driven inverter multi‐variable refrigerant flow system to show the validity of the proposed method for evaluating DC PQ. © 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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32. Polyinosinic‐polycytidylic acid accelerates intestinal stem cell proliferation via modulating Myc expression.
- Author
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Zeng, Huihong, Tang, Jiahui, Yue, Mengzhen, Cheng, Jiaoqi, Fan, Ying, Li, Manjun, Zhang, Xinxin, Li, Huan, Duan, Hongyi, Zhang, Minqing, Fan, Guangqin, Zhu, Qingxian, and Shao, Lijian
- Subjects
STEM cells ,DOUBLE-stranded RNA ,CELL proliferation ,DAMAGE models ,INTESTINAL injuries - Abstract
It is well known that exposure of double‐stranded RNA (dsRNA) to intestine immediately induces villus damage with severe diarrhea, which is mediated by toll‐like receptor 3 signaling activation. However, the role of intestinal stem cells (ISCs) remains obscure during the pathology. In the present study, polyinosinic‐polycytidylic acid (poly[I:C]), mimicking viral dsRNA, was used to establish intestinal damage model. Mice were acutely and chronically exposed to poly(I:C), and ISCs in jejunum were analyzed. The results showed that the height of villus was shorter 48 hr after acute poly(I:C) exposure compared with that of controls, while chronic poly(I:C) treatment increased both villus height and crypt depth in jejunum compared with control animals. The numbers of ISCs in jejunum were significantly increased after acute and chronic poly(I:C) exposure. Poly (I:C)‐stimulated ISCs have stronger capacities to differentiate into intestine endocrine cells. Mechanistically, poly(I:C) treatment increased expression of Stat1 and Axin2 in the intestinal crypt, which was along with increased expression of Myc, Bcl2, and ISC proliferation. These findings suggest that dsRNA exposure could induce ISC proliferation to ameliorate dsRNA‐induced intestinal injury. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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33. Correlation study on mtDNA polymorphisms as potential risk factors in aggressive periodontitis by NGS.
- Author
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Shi, Qiao, Luan, Qingxian, Wang, Xiaoxuan, and Cai, Yu
- Subjects
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DNA analysis , *CHI-squared test , *STATISTICAL correlation , *ETHNIC groups , *GENETIC polymorphisms , *MITOCHONDRIA , *PERIODONTITIS , *POLYMERASE chain reaction , *RISK assessment , *MULTIPLE regression analysis , *SEQUENCE analysis , *ODDS ratio , *DISEASE risk factors - Abstract
Objectives: Using next‐generation sequencing (NGS) to determine whether aggressive periodontitis is associated with specific mitochondrial polymorphisms. Materials and Methods: A total of 165 unrelated Han Chinese were enrolled in the study. We analyzed the mitochondrial DNA (mtDNA) in 97 patients with aggressive periodontitis and 68 healthy controls by NGS. The mitochondrial DNA was L‐PCR‐amplified and subsequently sequenced by an Illumina Genome Analyzer (NGS). Chi‐square tests were used to assess the differences between the two groups. In cases of significant difference, multivariate logistic regression models were further used to analyze the association between mtDNA polymorphisms and aggressive periodontitis. Results: Significant association was observed between aggressive periodontitis and eight mitochondrial polymorphisms: "8860G‐10400C" (OR = 2.828, p =.002), "8701A" (OR = 2.308, p =.005), "12705C‐10398A" (OR = 2.683, p =.002), "9540C" (OR = 3.838, p =.001) and "10873T‐15043G" (OR = 4.375, p =.001). Conclusions: The pathogenesis of aggressive periodontitis is complicated, and its heredity is not well characterized. Our study was the first to use next‐generation sequencing and found that 8860G‐10400C, 8701A, 12705C‐10398A, 9540C, and 10873T‐15043G are associated with aggressive periodontitis in the Han Chinese population. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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34. Measuring the subgingival microbiota in periodontitis patients: Comparison of the surface layer and the underlying layers.
- Author
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Liu, Guojing, Chen, Feng, Cai, Yu, Chen, Zhibin, Luan, Qingxian, and Yu, Xiaoqian
- Subjects
FILTER paper ,DENTAL plaque ,EUBACTERIALES ,FUSOBACTERIUM ,PORPHYROMONAS gingivalis ,STATISTICAL correlation - Abstract
Periodontitis is a major cause of tooth loss in adults that initially results from dental plaque. Subgingival plaque pathogenesis is affected by both community composition and plaque structures, although limited data are available concerning the latter. To bridge this knowledge gap, subgingival plaques were obtained using filter paper (the fourth layer) and curette (the first‐third layers) sequentially and the phylogenetic differences between the first–third layers and the fourth layer were characterized by sequencing the V3–V4 regions of 16S rRNA. A total of 11 phyla, 148 genera, and 308 species were obtained by bioinformatic analysis, and no significant differences between the operational taxonomic unit numbers were observed for these groups. In both groups, the most abundant species were Porphyromonas gingivalis and Fusobacterium nucleatum. Actinomyces naeslundii, Streptococcus intermedius, and Prevotella intermedia possessed relatively high proportions in the first–third layers; while in the fourth layer, both traditional pathogens (Treponema denticola and Campylobacter rectus) and novel pathobionts (Eubacterium saphenum, Filifactor alocis, Treponema sp. HOT238) were prominent. Network analysis showed that either of them exhibited a scale‐free property and was constructed by two negatively correlated components (the pathogen component and the nonpathogen component), while the synergy in the nonpathogen component was lower in the first–third layers than that in the fourth layer. After merging these two parts into a whole plaque group, the negative/positive correlation ratio increased. With potential connections, the first–third layers and the fourth layer showed characteristic key nodes in bacterial networks. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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- View/download PDF
35. Isoprenaline protects intestinal stem cells from chemotherapy-induced damage.
- Author
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Zeng, Huihong, Li, Huan, Yue, Mengzhen, Fan, Ying, Cheng, Jiaoqi, Wu, Xincheng, Xu, Rui, Yang, Wuping, Li, Manjun, Tang, Jiahui, Chen, Hongping, Kuang, Bohai, Fan, Guangqin, Zhu, Qingxian, and Shao, Lijian
- Subjects
STEM cells ,ENTERIC nervous system ,INTESTINES ,SMALL intestine ,CELL cycle ,EPITHELIAL cells ,NEURONS ,RESEARCH ,PHOSPHOTRANSFERASES ,ISOPROTERENOL ,ANIMAL experimentation ,RESEARCH methodology ,ANTINEOPLASTIC agents ,APOPTOSIS ,MEDICAL cooperation ,EVALUATION research ,COMPARATIVE studies ,INTESTINAL mucosa ,MICE - Abstract
Background and Purpose: Damage to intestinal epithelial cells and mucosa limits the effectiveness of several anti-cancer chemotherapeutic agents but the underlying mechanism (s) remain unknown. Little is known of how enteric nervous system regulates proliferation, differentiation, impairment, and regeneration of intestinal stem cells. Here we have investigated the effects of isoprenaline on the damaged intestinal stem cells induced by chemotherapeutic treatments in mice.Experimental Approach: The effects of inhibiting sympathetic and parasympathetic nerves on intestinal stem cells were examined in male C57BL/6J mice. Protection by isoprenaline of intestinal stem cells was assessed in the presence or absence of 5-fluorouracil (5FU) or cisplatin. Cellular apoptosis, cell cycle, PI3K/Akt signalling, and NF-κB signalling in intestinal stem cells were mechanistically evaluated.Key Results: The sympathetic nerve inhibitor 6-OHDA decreased the number and function of intestinal stem cells. 5FU or cisplatin treatment damaged both intestinal stem cells and sympathetic nerves. Notably, isoprenaline accelerated the recovery of intestinal stem cells after 5FU or cisplatin treatment. This protective effect of isoprenaline on damaged intestinal stem cells was mediated by β2 -adrenoceptors. The benefits of isoprenaline were mainly mediated by inhibiting cellular apoptosis induced by 5FU treatment, which might contribute to fine-tuning regulating NF-κB signalling pathway by isoprenaline administration.Conclusions and Implications: Treatment with isoprenaline is a new approach to ameliorate the damage to intestinal stem cells following exposure to cancer chemotherapeutic agents. [ABSTRACT FROM AUTHOR]- Published
- 2020
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36. MFN2 silencing promotes neural differentiation of embryonic stem cells via the Akt signaling pathway.
- Author
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Yi, Siqi, Cui, Chenghao, Huang, Xiaotian, Yin, Xiaohui, Li, Yang, Wen, Jinhua, and Luan, Qingxian
- Subjects
EMBRYONIC stem cells ,CELL morphology ,MITOFUSIN 2 ,CELL proliferation ,MITOCHONDRIAL proteins - Abstract
Mitofusin 2 (MFN2) is a regulatory protein participating in mitochondria dynamics, cell proliferation, death, differentiation, and so on. This study aims at revealing the functional role of MFN2 in the pluripotency maintenance and primitive differetiation of embryonic stem cell (ESCs). A dox inducible silencing and routine overexpressing approach was used to downregulate and upregulate MFN2 expression, respectively. We have compared the morphology, cell proliferation, and expression level of pluripotent genes in various groups. We also used directed differentiation methods to test the differentiation capacity of various groups. The Akt signaling pathway was explored by the western blot assay. MFN2 upregulation in ESCs exhibited a typical cell morphology and similar cell proliferation, but decreased pluripotent gene markers. In addition, MFN2 overexpression inhibited ESCs differentiation into the mesendoderm, while MFN2 silencing ESCs exhibited a normal cell morphology, slower cell proliferation and elevated pluripotency markers. For differentiation, MFN2 silencing ESCs exhibited enhanced three germs' differentiation ability. Moreover, the protein levels of phosphorylated Akt308 and Akt473 decreased in MFN2 silenced ESCs, and recovered in the neural differentiation process. When treated with the Akt inhibitor, the neural differentiation capacity of the MFN2 silenced ESCs can reverse to a normal level. Taken together, the data indicated that the appropriate level of MFN2 expression is essential for pluripotency and differentiation capacity in ESCs. The increased neural differentiation ability by MFN2 silencing is strongly related to the Akt signaling pathway. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
37. Circularly Polarized Luminescence of Aluminum Complexes for Chiral Sensing of Amino Acid and Amino Alcohol.
- Author
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Jin, Qingxian, Wang, Fulin, Chen, Shuyu, Zhou, Liming, Jiang, Hejin, Zhang, Li, and Liu, Minghua
- Subjects
- *
AMINO alcohols , *AMINO acids , *CIRCULAR dichroism , *NUCLEAR magnetic resonance spectroscopy , *SCHIFF bases , *X-ray crystallography - Abstract
Determination of the absolute configuration (AC) of chiral molecules is a key issue in many fields related to chirality such as drug development, the asymmetric reaction screening, and the structure determination of natural compounds. Although various methods, such as X‐ray crystallography and NMR spectroscopy, are used to determine the AC, a simple and cheap alternative method is always anticipated. So far, electronic circular dichroism (ECD) spectroscopy has been widely used to ascertain the AC and enantiomeric excess (ee) values by applying appropriate organic probes. Here, circularly polarized luminescence (CPL) spectroscopy was applied to determine the AC and ee values of a series of amino acid and amino alcohol. The measurements were conducted by mixing the amino acids or amino alcohols with an achiral 1‐hydroxy‐2‐naphthaldehyde. Upon in situ formation of the Schiff base complexes, the system showed emission enhancement and CPL in the presence of Al3+, whose intensity and sign can be used to assign the chiral sense of the amino acids and amino alcohols. The authenticity of the method was further compared with the established CD spectroscopy, revealing that CPL spectra of formed Al3+ complex were effective to determine the AC of chiral species. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
38. Natural 4‐year periodontal progression of mandibular first molars in Chinese villagers based on radiographic records.
- Author
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Pei, Xiyan, Ouyang, Xiangying, Luan, Qingxian, Suda, Reiko, and Cao, Caifang
- Abstract
Background: To report 4‐year natural periodontal progression of mandibular first molars based on radiographic records in 15 to 44‐year‐old Chinese villagers. Methods: In 1992 (N = 486) and 1996 (N = 413), panoramic radiographs were recorded. Tooth loss of mandibular first molars was calculated. Relative bone height (RBH), intrabony defect (IBD) depth, and furcation involvement (FI) were measured on 918 and 755 mandibular first molars in 1992 and 1996, respectively. The progression of the three parameters and their relationship with widened periodontal ligament space (WPDL) were analyzed. Results: In 1992, of 31 lost mandibular first molars, 29 belonged to the 35‐ to 44‐year age group. At 4‐year follow‐up, five of eight lost teeth belonged to the 35‐ to 44‐year age group. RBH decreased from 83% in 1992 to 77% in 1996. RBH progression was significantly faster in the 25‐ to 34‐ and 35‐ to 44‐year age groups than in the 15‐ to 24‐year age group. The mean IBD depth was 2.81 ± 0.55 mm (n = 32) in 1992 and 3.70 ± 0.73 mm (n = 33) in 1996. Prevalence of FI increased from 20.8% to 27.4%. Teeth with WPDL showed greater RBH and IBD progression than those without WPDL (RBH: 12% ± 1% versus 6% ± 0.01%, P < 0.001; IBD depth: 0.31 ± 0.08 versus 0.01 ± 0.00 mm, P <0.001). FI‐area progression in teeth with WPDL showed a trend of greater expansion than in those without WPDL (0.92 ± 0.18 versus 0.56 ± 0.11 mm2, P = 0.051). Conclusions: Tooth loss mainly occurred in the 35‐ to 44‐year age group. RBH progression was faster in the 25‐ to 44‐year age group. WPDL was associated with progression of RBH, IBDs, and FI. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
39. SIRT1 gene polymorphisms are associated with nondiabetic type 1 cardiorenal syndrome.
- Author
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Hou, Jiebin, Xie, Xinyue, Tu, Qingxian, Li, Jie, Ding, Jiarong, Shao, Guojian, Jiang, Qianfeng, Yuan, Li, and Lai, Xueli
- Subjects
GENETIC polymorphisms ,ACUTE kidney failure ,SYNDROMES ,HAPLOTYPES ,POPULATION of China ,HEART diseases ,CARDIO-renal syndrome - Abstract
Type 1 cardiorenal syndrome (CRS1) is characterized by acute cardiac disease (e.g., acute heart failure [AHF]), leading to acute kidney injury. Sirtuin 1 (SIRT1), an NAD+‐dependent deacylase, has been found to be associated with CRS1. To confirm whether a correlation exists between SIRT1 variants and the risk of CRS1, the association between the prevalence of CRS1 and single‐nucleotide polymorphisms (SNPs) within the SIRT1 gene was investigated in AHF patients. A total of 316 Chinese AHF participants (158 patients with CRS1 and 158 age‐ and sex‐matched controls) were recruited for the present observational study to investigate the association between nine common SIRT1 SNPs (i.e., rs7895833 G > A, rs10509291 T > A, rs3740051 A > G, rs932658 A > C, rs33957861 C > T, rs7069102 C > G, rs2273773 T > C, rs3818292 A > G, and rs1467568 A > G) and the susceptibility to CRS1. Significant differences in genotype distribution between the control and CRS1 groups were found for rs7895833 and rs1467568. After applying a Bonferroni adjustment, the A allele of rs7895833 was still found to be protective (p = 0.001; odds ratio [OR] = 0.77) against CRS1 in this study population. The AA genotype of rs7895833 and the GA genotype of rs1467568 were associated with a significantly reduced risk of CRS1 (OR = 0.23 and 0.49, respectively). rs7895833 and rs1467568 were further analyzed as a haplotype, and the GA haplotype (rs7895833‐rs1467568) exhibited a significant association with CRS1 (p = 0.008), while the AA haplotype showed a significant protective effect (p = 0.022). Our study showed that SIRT1 rs7895833 and rs1467568 polymorphisms had a significant effect on the risk of developing CRS1 in a population in China. [ABSTRACT FROM AUTHOR]
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- 2019
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40. Prognosis of fetuses with ventriculomegaly: An observational retrospective study.
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Chang, Qingxian, Peng, Yixian, Huang, Qitao, Zhong, Mei, Huang, Liping, Li, Jing, and Chen, Cuihua
- Abstract
Objective: To investigate the prognosis of fetuses with ventriculomegaly (VM).Methods: Clinical data were collected from 234 cases of fetal VM diagnosed by ultrasound between March 2010 and July 2016. VM progression was monitored, and karyotyping and infection screening performed. Magnetic resonance imaging (MRI) was performed where increasing ventricular diameter was noted. Neonatal behavioral neurological assessment (NBNA) was carried out after birth, and Bayley Scales of Infant Development assessment at 6 months.Results: The in utero outcomes of Group A were better than Group B in 173 pregnancies. Isolated VM (IVM) was associated with better prognosis than nonisolated VM (NIVM); the regression rates were 74.6% (59/79) and 52.1% (49/94), respectively (χ2 = 10.222, .006). The NBNA scores were significantly higher in Group A than Group B (χ2 = 4.231, .004), but not significantly different between IVM and NIVM. The composition ratios of both the psychomotor and mental developmental index (PDI and MDI) scores were not significantly different between Groups A and B (Z = 1.869, .062 and Z = 0.826, .409, respectively). Significant differences in in utero outcomes were observed between IVM and NIVM cases in Groups A and B.Conclusions: Fetal VM prognosis is affected by the width of ventricle, chromosome abnormalities, coexisted abnormalities, and in utero progression. [ABSTRACT FROM AUTHOR]- Published
- 2019
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41. Decision making with intuitionistic linguistic preference relations.
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Meng, Fanyong, Tang, Jie, An, Qingxian, and Chen, Xiaohong
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DECISION making ,INTUITIONISTIC mathematics ,LINEAR programming ,LINEAR models (Communication) ,AGGREGATION operators - Abstract
To address the preferred and nonpreferred degrees of linguistic variables, this paper introduces intuitionistic linguistic preference relations (ILPRs) that apply intuitionistic linguistic variables (ILVs) to denote the decision makers' preferences. To judge the consistency of ILPRs, a consistent concept is introduced, and a consistency index is defined. When ILPRs are unacceptably inconsistent, a method to improve the consistency is introduced. Then, an approach to rank ILVs is introduced. In some situations where ILPRs might be incomplete, the consistency‐based linear programming model is constructed to evaluate the missing values. Considering group decision making, a group consensus index is defined, and its several desirable properties are discussed. Meanwhile, an acceptability‐based consistency and consensus approach is developed, and the associated example is offered to show the efficiency of the proposed procedure. [ABSTRACT FROM AUTHOR]
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- 2019
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42. Extended state observer‐based sliding mode fault‐tolerant control for unmanned autonomous helicopter with wind gusts.
- Author
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Yan, Kun, Chen, Mou, Wu, Qingxian, and Jiang, Bin
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This study proposes a sliding mode fault‐tolerant control (FTC) scheme for the medium‐scale unmanned autonomous helicopter with rotor flapping dynamics in the presence of wind gusts and actuator faults using extended state observer technique. The radial basis function neural networks are employed to tackle the unknown non‐linear interaction functions and adaptive neural network extended state observers are constructed to estimate the unknown wind gusts. Meanwhile, the adaptive fault observers are developed to estimate the fault parameters in position, attitude and flapping motion subsystems. With the aim of obtaining satisfactory trajectory tracking performance, a robust adaptive sliding mode FTC scheme is presented based on the backstepping sliding mode control technique and the closed‐loop system stability is rigorously proved via Lyapunov analysis. Simulation results are carried out to validate the effectiveness of the proposed control method. [ABSTRACT FROM AUTHOR]
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- 2019
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43. Robust adaptive active fault‐tolerant control of UAH with unknown disturbances and actuator faults.
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Yan, Kun, Chen, Mou, Jiang, Bin, and Wu, Qingxian
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TRACKING control systems ,ACTUATORS ,ROBUST control ,ROTOR dynamics ,CLOSED loop systems ,COMPUTER simulation - Abstract
Summary: This paper proposes a robust active fault‐tolerant control (AFTC) approach for medium‐scale unmanned autonomous helicopter (UAH) with rotor flapping dynamics in the presence of unknown external disturbances and actuator faults. The robust items are adopted to improve the disturbance rejection capability of the UAH system. The adaptive fault observers are developed to estimate the fault parameters and the fault detection (FD) algorithms are presented to detect the actuator faults in different loops. In order to obtain satisfactory trajectory tracking performance, a backstepping‐based robust AFTC scheme is designed for the simplified 6‐degree‐of‐freedom (DOF) UAH nonlinear dynamics model and the global stability of the closed‐loop system is proved by using the Lyapunov method. Several groups of numerical simulation results are carried out to verify the effectiveness of the developed method. [ABSTRACT FROM AUTHOR]
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- 2019
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44. The effects of direct‐acting antiviral agents on the frequency of myeloid‐derived suppressor cells and natural killer cells in patients with chronic hepatitis C.
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Li, Yiting, Zeng, Yingfu, Zeng, Guofen, Li, Jianguo, Zhang, Xiaohong, Cai, Qingxian, Chen, Youming, and Lin, Chao‐Shuang
- Abstract
Currently, hepatitis C antiviral therapy is entering a new era with the use of direct‐acting antiviral (DAA) agents. However, the precise immunological influences of DAA therapy in patients with chronic hepatitis C (CHC) are insufficiently understood. This study aimed to investigate the effects of DAA therapy on the frequency of myeloid‐derived suppressor cells (MDSCs), T lymphocytes, and natural killer (NK) cells in patients with CHC. Thirty‐two treatment‐naive CHC patients were treated with DAA therapy, and the frequency of immune cells was analyzed by flow cytometry at various time points during and after therapy. Sixteen healthy donors were recruited for comparison. DAA therapy decreased the frequency of MDSCs and monocytic MDSCs in patients with CHC to a normal level. DAA therapy also increased the CD8+ T and NK cell levels in patients with CHC. In addition, activation (NKp30 and NKp46) and inhibitory (NKG2A) receptors on NK cells were downregulated to yield an NK cell phenotype resembling that observed in the healthy controls. This study provides insight into the normalization of immune cell levels under DAA therapy and indicates that restoration of the immune system in patients with CHC strongly supports long‐term curative hepatitis C virus eradication. 1. This study provides the first description of the specific restoration of MDSC and M?MDSC function by DAA therapy in patients with CHC. 2. These results supports that the existence of immune injury caused by HCV infection was confirmed. 3. This study indicates that the recovery of the levels of the immune system in patients with CHC supports the clearance of HCV and the elimination of HCV infection. [ABSTRACT FROM AUTHOR]
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- 2019
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45. Inverse optimal control for unmanned aerial helicopters with disturbances.
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Ma, Haoxiang, Chen, Mou, and Wu, Qingxian
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OPTIMAL control theory ,DRONE aircraft ,HELICOPTERS ,HAMILTON-Jacobi-Bellman equation ,NONLINEAR control theory - Abstract
Summary: This paper proposes an optimal control method of an unmanned aerial helicopter (UAH) with unknown disturbances. Solving the Hamilton‐Jacobi‐Bellman (HJB) equation is considered as the common approach to design an optimal controller under a meaningful cost function when facing the nonlinear optimal control problem. However, the HJB equation is hard to solve even for a simple problem. The inverse optimal control method that avoids the difficulties of solving the HJB equation has been adopted. In this inverse optimal control approach, a stabilizing optimal control law and a particular cost function that are obtained by a control Lyapunov function are required. An integrator backstepping method is used in designing the optimal control law of the UAH. Furthermore, a disturbance‐observer–based control (DOBC) approach has been adopted in the optimal control law for dealing with the unknown disturbances of the UAH system. Simulation results have been given to certify the stability of the nonlinear UAH system and the validity of this developed control method. [ABSTRACT FROM AUTHOR]
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- 2019
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46. Maternal obesity and risk of cerebral palsy in children: a systematic review and meta-analysis.
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Zhang, Jian, Peng, Linrui, Chang, Qingxian, Xu, Ruoting, Zhong, Nanbert, Huang, Qitao, Zhong, Mei, and Yu, Yanhong
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WEIGHT gain in pregnancy ,CEREBRAL palsy ,DISEASE risk factors ,HEALTH of mothers ,CHILDREN with cerebral palsy ,SYSTEMATIC reviews ,META-analysis ,MEDLINE ,OBESITY ,ONLINE information services ,PREGNANCY complications - Abstract
Copyright of Developmental Medicine & Child Neurology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2019
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47. The Temporal and Spatial Distribution Characteristics of Air Pollution Index and Meteorological Elements in Beijing, Tianjin, and Shijiazhuang, China.
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Shi, Huading, Critto, Andrea, Torresan, Silvia, and Gao, Qingxian
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AIR pollution ,SPATIAL distribution (Quantum optics) ,METEOROLOGY ,AIR quality ,EMISSIONS (Air pollution) - Abstract
With rapid economic development and continuous population growth, several important cities in China suffer serious air pollution, especially in the Beijing–Tianjin–Hebei economic developing area. Based on the daily air pollution index (API) and surface meteorological elements in Beijing, Tianjin, and Shijiazhuang (the capital of Hebei province) from 2001 to 2010, the relationships between API and meteorological elements were analyzed. The statistical analysis focused on the relationships at seasonal and monthly average scales, on different air pollution grades and air pollution processes. The results revealed that the air pollution conditions in the 3 areas gradually improved from 2001 to 2010, especially during summer; the worst conditions in air quality were recorded in Beijing in spring due to the influences of dust, and in Tianjin and Shijiazhuang in winter due to household heating. Meteorological elements exhibited different influences on air pollution, showing similar relationships between API in monthly averages and 4 meteorological elements (i.e., the average, maximum, and minimum temperatures; maximum air pressure; vapor pressure; and maximum wind speed), whereas the relationships on a seasonal average scale demonstrated significant differences. Compared with seasonal and monthly average scales of API, the relation coefficients based on different air pollution grades were significantly lower, whereas the relationship between API and meteorological elements based on air pollution processes reduced the smoothing effect due to the average processing of seasonal and monthly API and improved the accuracy of the results. Finally, statistical analysis of the distribution of pollution days in different wind directions indicated the directions of extreme and maximum wind speeds that mainly influence air pollution, representing valuable information that could support the definition of air pollution control strategies through the identification of the regions (and the located emission sources) where the implementation of emission reduction actions should be focused. Integr Environ Assess Manag 2018;14:710–721. © 2018 SETAC Key Points: The relationships between air pollution index and meteorological elements in 3 Chinese cities were analyzed.Meteorological elements exhibited different influences on air pollution in temporal and spatial scales.Statistical analysis of the distribution of pollution days in different wind directions was conducted.Comparisons of 6 representative types of air pollution process were made. [ABSTRACT FROM AUTHOR]
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- 2018
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48. Comparative study of periodontal differentiation propensity of induced pluripotent stem cells from different tissue origins.
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Li, Jingwen, Yin, Xiaohui, and Luan, Qingxian
- Abstract
Background: Despite being almost identical to embryonic stem cells, induced pluripotent stem cells (iPSCs) have been shown to possess a residual somatic memory that favors their differentiation propensity into donor tissue. To further confirm this assumption, we compare for the first time the periodontal differentiation tendency of human gingival fibroblast-derived iPSCs (G-iPSCs) and human neonatal skin fibroblast-derived iPSCs (S-iPSCs) to assess whether G-iPSCs could be more efficiently induced toward periodontal cells.Methods: We induced G- and S-iPSCs under the treatment of growth/differentiation factor-5 and connective tissue growth factor, respectively, for 14 days. Immunofluorescence staining and real-time polymerase chain reaction were used to compare their expression levels of related markers. Furthermore, a hydrogel carrier was developed to seed these periodontal progenitors for subcutaneous implantation in non-obese diabetic-severe combined immunodeficiency disease mice. Their differentiated periodontal phenotype maintenance was further assayed by HE observation, immunohistochemical staining and immunofluorescence co-localization with pre-labeled PKH67.Results: As expected, both iPSCs were inclined to differentiate back into their original lineage by expressing higher markers at both gene and protein levels in vitro. HE observation of G-iPSCs-seeded hydrogel constructs present more mineralized structure formation than S-iPSCs-seeded ones. Immunohistochemical staining and immunofluorescence analysis also showed stronger positive staining for periodontal related markers in G-iPSCs-seeded hydrogel constructs.Conclusions: Our results preliminarily confirmed that both G- and S-iPSCs were inclined to differentiate back into their original tissue in vitro. Animal study further confirmed the phenotype maintenance of periodontal differentiated G-iPSCs, which highlighted their significant implications for therapeutic use in periodontal regeneration. [ABSTRACT FROM AUTHOR]- Published
- 2018
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49. Ionic Skin with Biomimetic Dielectric Layer Templated from Calathea Zebrine Leaf.
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Qiu, Zhiguang, Wan, Yongbiao, Zhou, Wohua, Yang, Jingyi, Yang, Junlong, Huang, Jun, Zhang, Jianming, Liu, Qingxian, Huang, Siya, Bai, Ningning, Wu, Zhigang, Hong, Wei, Wang, Hong, and Guo, Chuan Fei
- Subjects
BIOMIMETIC materials ,CALATHEA ,DIELECTRICS ,ELECTRIC double layer ,ARTIFICIAL intelligence ,HUMAN-machine systems - Abstract
Abstract: Flexible electronic skins (e‐skins) with high sensitivity and broad‐range pressure sensing are highly desired in artificial intelligence, and human–machine interaction. Capacitive‐type e‐skins have a simple configuration, but the change in dimensions of the dielectric layer is often quite limited, although introducing surface microstructures might improve the sensitivity in some extent. Moreover, such surface structures typically require costly microfabrication methods to fabricate. Here, a low‐cost microstructured ionic gel (MIG) with uniform cone‐like surface microstructures for high‐performance capacitive e‐skins is reported. The MIG film is templated from a Calathea zebrine leaf using soft lithography, and sandwiched by two flexible electrodes. The device exhibits a low limit of detection down to 0.1 Pa, a ultrahigh sensitivity of 54.31 kPa
−1 in the low pressure regime (<0.5 kPa), and the sensitivity keeps larger than 1 kPa−1 over a broad‐range pressure from 0.1 Pa to 115 kPa. Electric double layers (EDL) form on both the top and bottom interfaces, and the area of EDL of the rough interface increases as the cones are compressed. Such ionic skins with biomimetic gel templated Calathea zebrine leaf allow for sensitive tactile sensing in the applications of human–machine interaction. [ABSTRACT FROM AUTHOR]- Published
- 2018
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50. P53 mediates lipopolysaccharide-induced inflammation in human gingival fibroblasts.
- Author
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Liu, Jia, Zeng, Jiajun, Wang, Xiaoxuan, Zheng, Ming, and Luan, Qingxian
- Abstract
Background: The role of reactive oxygen species (ROS) in activation of the inflammatory response has been proven in previous study using human gingival fibroblasts (HGFs) to lipopolysaccharide (LPS) from Porphyromonas gingivalis (Pg) stimulation, but its exact mechanism has not been established. ROS can be generated through increased oxidative phosphorylation. P53 originally identified as a tumor suppressor, has been demonstrated to be associated with energy metabolism. We proposed that LPS-induced inflammatory cytokines release in HGFs is mediated by interaction between P53 and ROS levels.Methods: HGFs were grown in medium with Pg LPS stimulation. Gene expression was performed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot analysis. HGFs were also processed by immunofluorescence to characterize the localization of P53. ROS was measured using a multimodal microplate reader and immunofluorescence microscopy. Cellular respiration levels were performed with a high-resolution respirometer. Cytokines secretion was confirmed by enzyme-linked immunosorbent assay.Results: LPS-induced P53 activity and localization in mitochondria led to cellular redox imbalance and mitochondrial dysfunction, thus triggered the cellular inflammatory response with increased secretion of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α. Furthermore, the cellular redox imbalance and inflammation induced by LPS were reversed by inhibiting P53 activity. P53 expression followed by LPS-induced inflammation was also be restricted by suppressing ROS generation.Conclusions: The present study shows that LPS-induced inflammation in HGFs is partially dependent on P53 modulating ROS and ROS stimulating P53, which suggests that P53 and ROS may form a feedback loop. The identification of this mechanism may provide potential new therapeutic strategies for periodontitis. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
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