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As a landscape with special significance, the landscape of fear exists in nature and human society. It has a huge ecological effect in biological system, and also has a profound impact on all aspects of material landscape and collective memory in man-land system. Landscape perception, landscape attitude and the interaction between landscape and human are important topics in contemporary geography research, but the research on the landscape of fear is still weak. Based on this, the study systematically sorts out the concept and research content of the landscape of fear, and discusses its application in tourism geography. The main conclusions of the study include: Firstly, the landscape of fear has formed fear ecology in the research from the perspective of ecology, and it is still in the exploratory stage in other disciplines. Although Tuan Yifu first put forward and studied the landscape of fear thoroughly from the perspective of human geography, the research on humanity society, geography and other related aspects is scattered. On the contrary, it is currently applied to ecological research and has rich research results. This shows that in addition to the maturity of its research in ecology, the landscape of fear in other disciplines remains to be explored. Secondly, under different disciplinary perspectives, the definition and research content of the landscape of fear are different, but in essence, its formation cannot be separated from the influence of subjective fear and external environment. On the one hand, the definition and research content of the landscape of fear in ecology are relatively consistent, which are animal predation risk perception. On the other hand, in other research disciplines, the concept and research content are mainly studied from the presentation form and perception of the landscape of fear between people and place/space. There are some differences in the research of the landscape of fear from different perspectives, but the "fear" perception of it must have an objective object that causes its fear. The landscape of fear is formed by the combination of subjective psychology and objective external. Thirdly, from the relationship among the landscape of fear, tourists and emotion, this paper finds that the application of the landscape of fear in tourism geography mainly focuses on emotional geography, dark tourism and emotional characteristics. There is no clear definition and research on the landscape of fear in tourism geography, but it can reflect the significance of the landscape of fear from the research contents such as emotional experience, dark tourism and memory of the place. Finally, the future prospects of the landscape of fear can be studied in tourism geography are as follows: 1) Based on its particularity, the landscape of fear in tourism geography will be discussed more deeply from different perspectives. 2) The psychological changes and emotional experience of tourists facing the landscape of fear can be studied. The emotional connection between man and land is one of the focuses of tourism geography research, and the landscape of fear integrates the complex emotions between people and landscape. And the emotional expression of the landscape of fear and the psychological impact of the landscape of fear on tourists can be studied. 3) Take dark tourism as the starting point to explore the landscape of fear. Dark tourism inevitably involves the research of tourism geography, and there is a certain connection between dark tourism and the landscape of fear. From the perspective of dark tourism, we can deeply explore the association with the landscape of fear, so as to better integrate the research of the landscape of fear and emotional geography. Although there is still a lack of research on the landscape of fear in humanity society, it has great research space. This paper combs and analyzes the landscape of fear and explores its application in the research of tourism geography, in order to enhance more attention and deepen its research in the field of tourism geography.

Objective To investigate thejob satisfaction and analyze influencing factors of health workers in basic public health service projects. Methods 164 primary medical institutions in Jiangxi Province were selected according to the method of phased cluster sampling. A questionnaire survey was conducted on the health personnel providing basic public health services in these institutions. Nonparametric test and ordered multiclass logistic regression were used to analyze the influencing factors of job satisfaction. Results Among the 3 018 basic public health service workers, the average score of job satisfaction was 24.52 ± 6.84 points. The proportion of very dissatisfied, relatively dissatisfied, average, fairly satisfied and very satisfied were 3.78%, 9.87%, 39.83%, 23.92% and 22.60%, respectively. Multiple linear regression analysis showed that educational background, job category, working years, income, overtime, training and performance reward mechanism had statistical significance on the overall job satisfaction score (P < 0.05). Conclusion The job satisfaction of health worker in basic public health service projects in Jiangxi Province was above average. In order to improve the job satisfaction, we can improve the promotion and guarantee mechanism for grassroots talents, strengthen vocational training, and improve the assessment mechanism. [ABSTRACT FROM AUTHOR]

Background and purpose: Multiple proinflammatory cytokines in tumorigenic microenvironment are involved in the acquired capability for invasive growth and metastasis. It is not clear whether protein kinase CβⅡ(PKCβⅡ) can modulate the secretion of proinflammatory cytokines to promote the progression of hepatocellular carcinoma (HCC). This study aimed to explore the function and mechanism of PKCβⅡ in the invasion of HCC to investigate the relationship between PKCβⅡ and tumor inflammatory microenvironment. Methods: The effect of conditioned medium from PKCβⅡ-overexpressing cells on the invasion of HCC cells was detected by the transwell assay. Serum-free culture supernatants were analyzed by cytokine arrays. The effect of PKCβⅡ overexpression on the expression of interleukin-6 (IL-6) in supernatants and at mRNA level was examined by enzyme- linked immunosorbent assay (ELISA) and real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR) respectively. The effects of IL-6 neutralizing antibody and IL-6 receptor (IL-6R) neutralizing antibody on PKCβⅡ overexpression-induced invasion of HCC cells were detected by the transwell assay. The expressions of signal transducer and activator of transcription 3 (STAT3) and P-STAT3 were detected by Western blot. Correlation of PKCβⅡ with the expression of IL-6 in clinical HCC cases was analyzed using the nonparametric Spearman test. Results: Conditioned medium obtained from PKCβⅡ-overexpressing cells significantly induced the invasiveness of Huh7 (P

Objective To investigate the expression of lncRNA SENCR in aortic dissection (AD) tissues of AD patients and its effect on and mechanism in the proliferation apoptosis of human vascular smooth muscle cells (HVSMCs). Methods HE staining was done to detect the pathological changes of AD tissues. Fluorescence in situ hybridization (FISH) and RT-qPCR were used to determine the expression of SENCR in the AD tissue and HVSMCs and the expression of SENCR and miR-206 in the tissues, respectively. HVSMCs were cultured and trans-fected with pcDNA3.1-SENCR overexpression plasmids, or pcDNA3.1 blank plasmid. Then cell proliferation and apoptosis were detected by CCK-8 method and Annexin V/PI double staining flow cytometry assay, respectively. Double luciferase report verified the targeting relationship between SENCR and miR-206. Results SENCR was mainly located in the cytoplasm and nucleus of HVSMCs. Compared with the normal tissue, the expression of SENCR in the AD tissues was down-regulated (P < 0.01), but the expression of miR-206 was up-regulated (P < 0.01). Overexpressed SENCR decreased the cell proliferation of HVSMCs (P < 0.01), but significantly increased the cell apoptosis of HVSMCs (P < 0.01). SENCR could target and negatively regulate miR-206. Conclusion The expression of SENCR is down-regulated in AD tissues, and overexpressed SENCR may inhibit the proliferation and promote the apoptosis of HVSMCs by targeting down-regulated miR-206. [ABSTRACT FROM AUTHOR]

In this paper, Weissella confusa (WC) and Lactobacillus plantarum (LP) were used to ferment sourdough with yeast alone and together, compared with the sourdough fermented with yeast alone (CK) to discuss the change of lactic acid bacteria number and organic acid content of different sourdoughs. And to discuss the effects of different sour¬doughs to steamed bread dough on water distribution, rheological properties and to steamed bread on quality and flavor. The results of the study found that the pH of the sourdough fermented with lactic acid bacteria remained stable after 24 h. The bacterial number of WC+LP group reached the highest at 24 h, which was 9.34 lg(CFU/g sourdough). After 24 h fermentation, the lactic acid content in LP group was 7.75 mg/g sourdough, and the acetic acid content in LP+WC group was 0.49 mg/g sourdough. The T2 relaxation time of steamed bread dough with sourdough was 235.43 ms and of CK group was 252.35 ms, The T2 relaxation time of these groups was shorter than that without sourdough which was 289.94 ms, and the viscoelasticity of steamed bread dough decreased. The addition of sourdough increased specific vol¬ume, reduced the hardness and improved the elasticity of steamed bread, the maximum specific volume of the LP+WC group was 2.17 mL/g, which was 20.56% higher than that of ordinary yeast bread, the hardness of the LP+WC group was reduced by 25.89% and the elasticity of the LP+WC group increased by 4.5% compared with that of ordinary dry yeast bread (OSB). GC-MS analysis showed that 35 flavor substances were detected in LP+WC group, with the largest variety. The results showed that the quality and flavor of steamed bread could be improved by the compound fermented sourdough with Weissella confusa and Lactobacillus plantarum, which laid a theoretical foundation for the next use of related bacteria to ferment sourdough. [ABSTRACT FROM AUTHOR]

In order to investigate the effect of debranching treatment on the structural characteristics and physicochemical properties of maize starch-chitosan complex. In this study, maize starch (MS) was used as raw material, pullulanase was used for enzymatic debranching, debranched maize starch-chitosan complex (DBS-CS) was prepared by mixing de- branched starch (DBS) and chitosan (CS) solution. The microstructure, particle size distribution, crystalline structure, molecular short-range ordered structure and rheological properties of the complex were determined. Results showed that the more chitosan attached to the particle surface of debranched maize starch-chitosan complex, the tighter the binding force between particles and the larger the average particle size of the complex, and improved thermal stability. The crys- tallinity of DBS and DBS-CS decreased after debranched, the crystal structure changed from A type to B type. The FTIR spectrums of and :H NMR spectroscopy showed that starch and chitosan could form complex, and the composite of debranched maize starch and chitosan had better effect. The debranched starch-chitosan complex had typical weak gel dynamic rheological behavior and pseudoplastic shear thinning behavior. This study provides a theoretical basis for obtaining a new type of green security complex modified starch. [ABSTRACT FROM AUTHOR]

The study was to enrich the control measures of Elizabethkingia miricola EMI and screen the strains with antagonistic effect on Elizabethkingia. The EMI antagonism was isolated by dilution coating method. Morphological observation, physiological and biochemical characteristics analysis and 16S rRNA gene sequence analysis were used to determine the classification status of the isolated strain LM-7. To study the optimal bacteriostatic conditions and active substances of antagonistic strain LM-7 against EMI. The results showed that LM-7 belonged to Streptomyces antibioticus which had the best antibacterial effect on EMI in PDA medium, the ratio of circle and diameter was 11.13. LM-7 contained polyketide synthase genes PKS-I and PKS-II and non-ribosomal peptide synthase genes NRPS, the antibacterial active components were related to non-ribosomal peptides and polyketide secondary metabolites, and its antibacterial activity mainly existed in the exocytic secretion of cells. The study indicates that strain LM-7 can be used as a candidate strain for EMI control, and its fermentation broth has the potential to study and develop novel structurally active compounds. [ABSTRACT FROM AUTHOR]

Objective To analyze the expression of immune cells and immunosuppressive factors in the immune microenvironment of glioblastoma. Methods A total of 30 glioma specimens, all of which were glioblastoma (IDH - wildtype), were surgically removed and completely preserved in the First Affiliated Hospital of Ji'nan University and Guangdong Sanjiu Brain Hospital from November 2020 to April 2021. T lymphocytes (CD3+ T cells, CD4+ T cells, CD8+ T cells), suppressive immune cells [FoxP3+ regulatory T cell (Treg)], immunosuppressive factors [transforming growth factor - β (TGF - β)], immunosuppressive factors [programmed cell death protein ligand 1 (PDL1)] in the immune microenvironment of glioblastoma were detected by immunohistochemistry. Results The proportion of CD4+ T cells in glioblastoma was very low. CD3+ T cells accounted for more than 3% in 15 cases (50%), and CD8+ T cells were similar to CD3+ T cells. Few FoxP3+ Treg cells were detected in only 2 cases (6.67%). The cytoplasm of 24 cases (80%) of glioblastoma showed strong positive expression of TGF - β, and its expression was correlated with the distribution of CD3+ T cells. No CD3+ T cells were found in the areas with high expression of TGF-β, and CD3+ T cells were widely distributed in the areas with low expression of TGF-β. PDL1 expression was non- detected. Conclusions TGF - β protein was highly expressed in glioblastoma, and future drugs or immunotherapies designed to target TGF-β may contribute to the clinical treatment of glioblastoma. [ABSTRACT FROM AUTHOR]

Objective·To investigate the expression and clinical significance of phospholipase A2 Group IIA (PLA2G2A) in kidney renal papillary cell carcinoma (KIRP), and provide new ideas for seeking KIRP targets. Methods·The expression level of PLA2G2A in pan-cancer and its relationship with prognosis and immune infiltration were analyzed by online software SangerBox. On this basis, the expression level of PLA2G2A in KIRP was analyzed with the help of the UCSC xena database; the correlation between PLA2G2A expression and prognosis and immune infiltration of KIRP were analyzed by using the UALCAN database and the TIMER database, respectively. In addition, the LinkedOmics database was used to analyze the related genes, Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway enrichment of PLA2G2A in KIRP. Results·PLA2G2A was significantly low expressed in 15 tumor samples from The Cancer Genome Atlas (TCGA) including KIRP. It was further validated that PLA2G2A was significantly lower expressed in KIRP with the help of Genotype-Tissue Expression (GTEx) database. The expression level of PLA2G2A was closely related to the prognosis and immune infiltration of various tumors. The higher the expression level of PLA2G2A in KIRP was, the worse the prognosis and the higher the abundance of immune infiltration were. GO analysis showed that PLA2G2A was mainly enriched in biological regulation and metabolic process in biological process (BP), cell membrane and nucleus in cell component (CC), and protein binding and ion binding in molecular function (MF). KEGG pathway enrichment analysis suggested that the pathways positively correlated with PLA2G2A were enriched in ribosome, cell cycle, proteasome, systemic lupus erythematosus and antigen processing and presentation, while the pathways negatively correlated with PLA2G2A were enriched in citrate cycle, pyruvate metabolism, and carbon metabolism. Conclusion· PLA2G2A is significantly lower expressed in KIRP. Unexpectedly, the higher the expression level of PLA2G2A in KIRP is, the worse the prognosis and the higher the abundance of immune infiltration are. In KIRP, the PLA2G2A positively correlated pathways are mainly enriched in cell cycle and immune-related pathways (such as systemic lupus erythematosus, antigen processing and presentation), while the negatively correlated pathways are mainly concentrated in citric acid cycle and pyruvate metabolism signaling pathways. Thus, it is needed to be further explored whether PLA2G2A plays a role in the development of KIRP as a tumor suppressor or an oncogene. [ABSTRACT FROM AUTHOR]

To further improve the evaluation accuracy of CO2 storage potential in saline layer, a new method for calculating the theoretical tectonic CO2 storage volume was proposed based on the material balance equation of CO2 tectonic storage process and the accurate calculation of underground volume of CO2 storage. As found in the results, the error of theoretical tectonic CO2 storage volume calculated by the new method was smaller than that of area method and volume method, which was only about 10%; the new method can predict the theoretical tectonic storage volume under both CO2 pressurized and pressure-retaining underground storage conditions; both theoretical tectonic CO2 storage volume and formation pressure showed a trend of increasing with the increase of injection time or injection-production ratio. The new method is of great significance to the study of CO2 tectonic storage and real-time dynamic control. [ABSTRACT FROM AUTHOR]

Although the side-scan sonar shipwreck target detection method based on the YOLOv5 algorithm has achieved good results in detection accuracy and speed, however, how to further improve the accuracy of small target detection under the background of complex ocean noise, reduce the missed alarm rate and false alarm rate of overlapping targets, and realize the lightweight of the model is an urgent issue to be solved. To this end, this paper innovatively integrates the structure of DETR (end-to-end object detection with transformers) and YOLOv5,and proposes a lightweight side-scan sonar shipwreck detection model based on the DETR-YOLO model. Firstly, a multi-scale feature complex fusion module is added to improve the detection ability of small targets. Then, the attention mechanism SENet (squeeze-and-excitation networks) is integrated strengthen the sensitivity to important channel features. Finally WBF (weighted boxes fusion) weighted fusion frame strategy is adopted to improve the positioning accuracy and confidence of the detection frame. The experimental results show that the AP_0.5 and AP_0. 5:0.95 values of this model in the test set reach 84. 5% and 57.7%, respectively, which are greatly improved compared with the Transfermer and YOLOv5a models. At the expense of smaller detection efficiency loss and weight increase, higher detection accuracy has been achieved. At the same time, it can improve the full-scene understanding ability and the small-scale overlapping target processing ability while meeting the needs of lightweight engineering deployment. [ABSTRACT FROM AUTHOR]

In order to clarify the species of pathogenic microorganisms causing postharvest decay of abiu fruit, the pathogens were isolated from naturally infected abiu during the postharvest storage using traditional tissue isolation method, and Koch's postulates was used to determine their pathogenicity. The pathogen identification were carried out according to the morphological characterization and phylogenetic tree (ITS and TUB2) analysis. The results showed that five obtained isolates caused similar disease symptoms when re-inoculated to healthy abiu, which indicated their pathogenicity. Five pathogens were identified as Lasiodiplodia theobromae, Neopestalotiopsis rosae, Diaporthe pseudomangiferae, Fusarium proliferatum and Aspergillus aculeatinus. The purpose of the study is to provide a scientific basis for effecive prevention and control of postharvest disease of abiu fruit and extension of the storage time. [ABSTRACT FROM AUTHOR]

China is the birthplace of foxtail millet, four traditional foxtail millet accessions of Qinzhouhuang, Taohuami, Longshanxiaomi, and Jingumi because of its good quality characteristics, has been selected as the royal tribute and is loved by people in Chinese history. To explore the genetic diversity of four Chinese famous foxtail millet and the genetic relationships among the namesakes, SSR and SRAP markers were used to analyze the genetic difference of 179 foxtail millet varieties. Results based on SSR markers showed that the genetic distance ranged from 0.0435 to 0.6304 with an average of 0.3267, the PIC was 0.2406, the allele frequency was 0.7845, and the genetic diversity was 0.2968. Based on UPGMA, 179 materials were clustered into 10 groups, and the clusters had certain correlation with their sources. The materials were divided into three groups based on structure and three groups based on principal component analysis. SRAP marker analysis revealed that the genetic distance ranged from 0.1818 to 0.9545 with an average of 0.6001, and the PIC, the allele frequency, and the genetic diversity were 0.5257, 0.5718, and 0.5688, respectively. Based on UPGMA, 179 materials were clustered into 14 groups. The materials were divided into three groups based on structure and principal component analysis. The groups were clearly divided and the origin of the groups was consistent with their source. [ABSTRACT FROM AUTHOR]

The rapid growth of fluctuating power sources, mainly wind and solar energy, has led to severe power imbalances and urgent need for developing the energy storage technology. Pumped storage is the largest and most mature energy storage mode by now and has become the energy storage mainstay in the power grid. Gravity energy storage can also realize similar function, by replacing the storage material "water" in pumped storage with other solid heavy objects. There are relevant reports about gravity energy storage abroad, while still lacking in China so far. In this paper, the present situation of gravity energy storage was analyzed, and a conceptual scheme, which includes the gravity turbine and the up and down storehouses, was proposed by analogy with pumped storage. Meanwhile, the working processes, principles of energy storage and power generation of gravity energy storage were clarified, and the power output formula was derived theoretically. According to scientific conception and comparative analysis, it is preliminarily estimated that the net height of gravity energy storage is about 100 m and the corresponding maximum single unit capacity can reach 10 MW. In addition, distributed planning can be adopted to realize flexible large-scale energy storage. Based on the exploratory analysis, four technology conceptualizations and key problems of gravity energy storage are proposed as follows: 1) The gravity turbine for converting the potential energy of heavy objects into rotating mechanical energy. The gravity turbine is developed which works similarly to the hydraulic turbine, the maximum transport capacity is more than ten tons per second and the target efficiency is 80%. Since the gravity turbine is the critical core component of gravity energy storage, more needs to be studied in the mechanical engineering applications. 2) The suitable layout of up and down storehouses. Combined with the actual geographical conditions, flexibly arrange the up and down storehouses. Using the space between up and down storehouses to store heavy objects can reduce the land occupation. The up and down storehouses layout, gravity turbine and conveying system should be discussed and demonstrated as a whole system since the former can affect the development and research of the others. 3) High efficiency conveying system for heavy objects, including lifting heavy objects from the down storehouse to the up storehouse and transporting them in the same storehouse. Because the commercial value of gravity energy storage is directly related to the conveyance energy consumption and system efficiency, extensive research is needed to find a safe, efficient, and feasible conveying system. 4) Reasonable selection of heavy objects. Concrete as the main material of heavy objects is more appropriate. The construction waste and local material are used as much as possible to reduce the impact on the environment. In addition, heavy objects should be standardization with the same specification and durability for long recycling. All in all, gravity energy storage has the significant advantages of environmental friendliness, flexible layout, high safety, long life, no self-discharge, etc., with outstanding research and development value and broad application prospects. However, gravity energy storage technology is still in the exploration stage. Further investigations of gravity energy storage are needed to promote the pre-study, program planning and technology development, which would provide backup support for the long-term development of new energy. [ABSTRACT FROM AUTHOR]

Indocyanine green (ICG), a cationic cyanine dye, has the advantages of low toxicity, high affinity and near-infrared emission. Therefore, as a kind of near-infrared organic fluorescent dye which can be used in clinical medicine, it has been widely applied in biological imaging, disease diagnosis and other fields. In this paper, the clinical application and tumor diagnosis and treatment of indocyanine green were discussed, and the relevant information about ICG was comprehensively introduced through examples. [ABSTRACT FROM AUTHOR]

Objective To investigate the overall state of the glycemic control in children with type 1 diabetes mellitus (T1DM) in a single center and analyze the related factors. Methods This cross sectional clinical based research was conducted among patients under 18 years old diagnosed with type 1 diabetes (the duration of diabetes>3 months) from the Diabetes Clinic of Beijing Children's Hospital from January 2015 to December 2019. The patients were required to receive a follow up every 3 months. The follow up data of the same patient were collected once a year. Glycosylated hemoglobin (HbA1c) was taken as the main research index (the selection principle was the median glycosylated hemoglobin per year). Demographic data included age at onset and at follow up, sex, duration of diabetes, years of follow up. In addition, clinical information on weight, height, modalities of insulin treatment (number of injections or pump therapy), the frequency of self monitoring of blood glucose (SMBG) per day or using of continuous glucose monitoring (CGM)/flash glucose monitoring (FGM) were collected. According to the years of follow-up, the patients were divided into 5 groups. According to the HbA1c control target (7.0%), the patients were divided into the good-control group (HbA1c<7.0%) and the poor-control group (HbA1c ≥7.0%). According to the age of the patients, they were divided into three groups (<5 years old group, 5 to 10 years old group and>10 years old group). The general situation of blood glucose control from 2015 to 2019 was compared by groups, and the related factors were analyzed by linear regression and two level logistic regression. Results A total of 1 976 patients with T1DM were collected (2015 n=362, 2016 n=410, 2017 n=415, 2018 n=384, 2019 n=405), the age was 10.09 (7.18, 12.85) years old; the duration of diabetes was 1.94 (0.88, 3.86) years, 49.5% (978/1 976) were male. There was no significant difference in age, sex and duration of disease among each groups (P>0.05), and comparable. HbA1c decreased from 7.4% (6.7%, 8.3%) in 2015 to 6.8% (6.1%, 7.6%) in 2019 (P< 0.01). The rate of achieved A1C target increased year by year [34.5% (125/362), 42.0% (172/410), 47.0% (195/415), 55.2% (212/384) and 56.3% (228/405), respectively], and the difference was statistically significant (Z=7.02, P<0.01). The HbA1C was positively correlated with age and duration of disease (r=0.095, 0.170 respectively, P<0.01). Logistic regression analysis showed that older of age, longer duration of disease and less frequency of daily blood glucose monitoring were the risk factors of failing to achieve HbA1c target. Conclusions From 2015 to 2019, HbA1c in children with T1DM has decreased year by year, and the rate of achieved A1C target has increased year by year, and it has increased by 1.63 times in 2019 compared with 2015. The increase in the use of CGM/FGM is the main factor to improve blood glucose control. [ABSTRACT FROM AUTHOR]

The plasticizer DINP is widely used in PVC consumer and industrial products. The health effect of DINP has become a research hotspot for its toxicity on multiple systems of human body. In this paper, the research progresses in related fields of study for recent years were reviewed. The endocrine toxicity, reproductive and developmental toxicity, cardiovascular toxicity, immunotoxicity, neurotoxicity and other toxic effects of DINP and its mechanisms were systematically described. The existing problems were summarized and future research directions was prospected. This study may provide references for the prevention and control of human health effects related to environmental DINP exposure. [ABSTRACT FROM AUTHOR]

Objective The time and the risk factors of virus nucleic acids negative conversion of coronavirus disease 2019 (COVID-19) patients were analyzed. Methods The clinical data of patients with COVID-19 admitted to Chongqing Public Health Medical Treatment Center from February 6 to March 9, 2020 were collected retrospectively. The clinical characteristics, treatment and outcome were described. The time of turning negative of nucleic acid was counted and the risk factors of turning negative of nucleic acid were analyzed. Results There were 104 confirmed cases of COVID-19, 56 males and 48 females, with an average age of (49.9 ± 15.5) years (12-86 years old). The average interval between clinical symptoms and medical treatment was 5.5 days. From the time point of clinical symptoms, the time needed for nucleic acid to turn negative was (19.8 ± 7.7) days, of which 32 cases (30.8%) turned negative within 14 days, 72 cases (69.2%) turned negative more than 14 days, and 14 cases (13.5%) turned negative more than 28 days. Univariate analysis showed that the time interval from clinical symptoms to medical treatment (6.7±4.4) days of nucleic acid conversion group after 14 days was longer than that (2.6 ± 1.8) days of conversion group within 14 days (P<0.05); the incidence of combined with pulmonary bacterial infection (25 cases, 34.7%), infection more than three pulmonary lobes (36 cases, 50.0%), severe patients (24 cases, 33.3%) and combined use of glucocorticoids were greater than those of conversion group within 14 days (all P<0.05). Multivariate analysis showed that there were significant differences in the time interval from symptoms to medical treatment and the proportion of three or more lobes involved in lung lesions between the two groups (P<0.05). Conclusions The risk factors of viral nucleic acid turning negative are the timeliness of medical treatment, combined with pulmonary bacterial infection, wide range of pulmonary lesions, clinical typing and combined use of glucocorticoids, especially the timeliness of medical treatment and the range of pulmonary lesions. [ABSTRACT FROM AUTHOR]

Objective To study the effect of cluster management based on Enhanced Recovery After Surgery ( ERAS ) in the perioperative period of liver transplantation for hepatocellular carcinoma. Methods 109 patients with hepatocellular carcinoma who underwent liver transplantation in Shenzhen Third People's Hospital from June 2018 to November 2019 were selected and divided into a control group (n =54 ) and an observation group (n =55 ) by the random number table method. The control group was given routine preoperative management, and the observation group was given ERAS-based cluster management. The operation time, intraoperative blood loss, blood transfusion volume, the incidence of hypothermia, the incidence of pressure ulcers, length of hospital stay, tumor-related indicators, half-year postoperative survival rate and incidence of complications were compared between the two groups. Results The operation time and hospital stay in the observation group were significantly shorter than those in the control group (both P < 0. 05 ). The volume of intraoperative blood loss and blood transfusion in the observation group were significantly less than that in the control group (both P < 0. 05 ). The incidence of hypothermia and pressure ulcers in the observation group were significantly lower than that in the control group (both P < 0. 05 ). Serum alpha-fetoprotein, glutamine transpeptilase and abnormal prothrombin in the observation group were significantly lower than those in the control group (all P <0. 05). The half-year survival rate of the observation group was significantly higher than that of the control group (P <0. 05). The total incidence of postoperative complications in the observation group was significantly lower than that in the control group (P <0. 05). Conclusion The application of cluster management based on ERAS in liver transplantation for hepatocellular carcinoma during the perioperative period can improve the surgical indicators of patients, improve the half-year survival rate after operation and reduce the incidence of complications. [ABSTRACT FROM AUTHOR]

Objective To understand the current status of the training of nursing assistants under the background of combination of medical and nursing, and to explore the countermeasures to improve the training quality for nursing assistants in care institutions for the elderly. Methods A self-designed questionnaire was used to investigate the general information, training status and training needs of nursing assistants in care institutions for the elderly. Results A total of 246 questionnaires were sent out, and a total of 239 valid responses were obtained for data analysis. There were 215 nursing assistants who had not received pre-employment training. The five main issues in elderly care included daily care, field service such as sanitation and hygiene, basic care, psychosocial nursing, nursing quality management. The content of current training consisted of daily care, emergency care, nursing evaluation and risk assessment, psychosocial nursing, basic nursing. The most favorite method of training was field demonstration, followed by lecture, emergency drill, one-to-one guidance and group discussion. The most in-demand knowledge in training was emergency care, followed by daily care, psychosocial nursing, basic care, nursing evaluation and risk assessment. Conclusion It is required to standardize training content, enhance the pre-job training and on-the-job training of nursing assistants in care institutions for the elderly, in order to improve the quality of aged care service. [ABSTRACT FROM AUTHOR]

A sequential extraction method was employed to determine and divide nitrogen forms into ion exchangeable form nitrogen (IEF-N), weak acid extractable form nitrogen (WAEF-N), strong alkali extractable form nitrogen (SAEF-N), strong oxidant extractable form nitrogen (SOEF-N) and non-extractable form nitrogen (NTN), in sediments from different areas of Lake Hongze for exploring its distribution characteristics and influence factors of various forms of sediment nitrogen. Moreover, multivariate statistical analysis was used to investigate the relationship between physical and chemical properties of sediments and various forms of nitrogen. The results showed that the transferable total nitrogen (TTN) content in the sediments ranged from 377.84 mg/kg to 1085.08 mg/kg with a mean value as 765.93 mg/kg, accounting for 69.76% of the total nitrogen (TN). TTN was a main part of TN, indicating the nitrogen in sediment of Lake Hongze has a high potential release risk. The sequence of each transformable nitrogen according to concentration was WAEF-N>SOEF-N>SAEF-N>IEF-N. The low correlation between IEF-N and TN suggested that TN in sediments cannot totally represent the release extend of endogenous nitrogen pollution in lake. The spatial distribution trends of all nitrogen forms but IEF-N and SAEF-N were consistent with that of TN, following as West Lake Area>Central Lake Area Including Lake Chengzi>Eastern Open Water Area. TTN, SOEF-N and NTN are extremely significantly correlated with TOC and TN, respectively (p<0.01), and IEF-N is significantly correlated with TOC and pH, respectively (p<0.05). Particle size had a weak correlationship with all different nitrogen forms. [ABSTRACT FROM AUTHOR]

BACKGROUND: Although it has been found in many studies that three-dimensional finite element analysis can be used in the study of knee joint biomechanics, there are few researches on different defect areas of medial condyle cartilage of the femur. OBJECTIVE: To analyze the stress change trend of perimeter articular cartilage before and after the occurrence of different defect areas of medial femoral condyle cartilage, providing biomechanical data for patients with knee medial femoral condyle cartilage defect. METHODS: One normal adult had been selected to establish a three-dimensional finite element model. Material mechanical properties were input to Abaques software with divided grid model. After controlling boundary condition with mechanical load, structural nonlinear finite element was calculated. First, the load stress distribution of knee cartilage and meniscus was observed under normal stress. Articular cartilage stress distribution was observed with load conditions in different defects (0, 6, 8, 10, 12, 14, 16, 18 and 20 mm) of medial femoral condyle. The stress changes on the cartilage were analyzed during the defect of medial femoral condyle. This study was approved by the Ethics Committee of First Affiliated Hospital of Kunming Medical University. The volunteer signed the informed consent. RESULTS AND CONCLUSION: (1) Material properties, boundary conditions and the introduction of loads were defined successfully. The stress cloud chart and its stress data were obtained from different diameter defects of cartilage in medial condyle of knee joint. According to statistical analysis, the stress on the femoral condyle and tibial plateau cartilage had significant changes compared with no defects when the medial femoral condyle cartilage had defects of 10 mm (area 0.78 cm² ) and 12 mm (area 1.13 cm² ). (2) The stress change trend of the cartilage of the medial condyle of the knee joint under the condition of different diameter defects was calculated based on the analysis of the application of three-dimensional finite element method. (3) Results suggest that the defect with the diameter of 10 mm (area 0. 78 cm² ) of medial femoral condyle may be the minimum diameter advised for operation intervention of cartilage repair. [ABSTRACT FROM AUTHOR]

Aiming at the problem of road detection in aerial images, a road extraction algorithm based on prediction and residual refinement networks is proposed. Firstly, the prediction network makes initial predictions. In order to improve the refinement ability of the segmentation network and learn higher-level road features, the dilated convolution and multi-kernel pooling modules are introduced in the pre-diction networks. Secondly, the residual refinement network will further refine the output of the prediction network and improve the ambiguity of the prediction network results. In addition, considering the small proportion of road pixels in aerial images, the network also combines binary cross entropy, structural similarity, and intersection over union loss functions to reduce road information loss. The experimental results on the Massachusetts road dataset show that the precision, recall, F value and accuracy reaches 99.3%, 95.7%, 97.3% and 95.1%, respectively. The intersection over union and structural similarity also reaches 94.8% and 84.3%, respectively. Compared with other algorithms, this proposed algorithm has certain application value. [ABSTRACT FROM AUTHOR]

Xinjiang and Gansu, are the critical junctures for the ancient Silk Road of China as well as the main cultivation areas of broomcorn millet. In this study, a total of 103 SSR primers and 216 millets were used to analyze the genetic diversity and population genetic structure which promotes the study on origin evolution and propagation path of broomcorn millet. The 299 alleles were detected with an average of 2.9 for each SSR. The mean values of Shannon-Weaver index, Ne, Nei were 0.7360, 0.6298, and 0.5497 respectively, and the range of PIC value was 0.0688-0.7786 with a mean of 0.4714, indicating the moderate polymorphism of these SSRs. The genetic differentiation was very small in terms of the inbreeding line number and genetic differentiation coefficient which were 0.5870 and 0.0383, respectively. The values of Na, Shannon-Weaver index, Nei, PIC of broomcorn millet accessions in Gansu were 2.8252, 0.7347, 0.4501, and 0.4674, respectively, which were higher than those in Xinjiang, indicating more abundant genetic diversity in Gansu. Two hundred and sixteen broomcorn millet accessions could be divided into five groups based on cluster analysis of genetic distance. Group I-IV had seven accessions with a distant genetic relationship with other samples. Ninety-six percent of accessions were distributed in group V, which were further divided into four subgroups at a genetic distance of 0.38. The main accessions of subgroups A and D came from Gansu, those of subgroups B and C were from Xinjiang, indicating that the accessions between Xinjiang and Gansu are obviously separated and permeated with each other. The result of genetic structure analysis was similar to that of UPGMA clustering, both of them related to their geographical distribution. [ABSTRACT FROM AUTHOR]

The visualization analysis of dispersion state of the filler m silicone rubber was based on the fluorescent labeling and the laser scanning confocal microscope. The fluorescent silica microspheres were modified by different silane coupling agents, and the contact angle analysis, thermogravimetnc analysis and fluorescence spectroscopy were used to describe its surface properties. Both hydrophobic effect and bound rubber content of modified fluorescent silica microspheres are KH-570>KH-560>KH-550. Visual analysis results show that the aver- age size of aggregates and network connectivity of KH-570 modified fluorescent silica microspheres were 2.61 ̡m and 47%, KH-560 modified it were 2.95 /im and 43% and KH-550 modified it were 3.32 f(m and 41 %. The visual analysis method of the modified fluorescent SiO2 microsphere is beneficial to observe the dispersion state of it m the silicone rubber, and this method can statistically analyze the particle size of the modified fluorescent SiO2 microsphere aggregates. This method is helpful to evaluate the dispersion state of the filler m the silicone rubber. [ABSTRACT FROM AUTHOR]

Fe3O4 nanoparticles were synthesized by co-precipitation method. 3D graphene was modified on the surface of Fe3O4 nanoparticles, and then covered with tetraethyl orthosilicate(TEOS) and vinyltrimethoxysilane (VTMO). Finally, the magnetic functional material Fe3O4@3DG@VTMO@MPS was synthesized by the polymerization of functional monomer 3-mercapto-1-propanesulfonate(MPS) on the surface using "thiol-ene" click chemistry. The structure, morphology and thermal stability of the functional materials were characterized by scanning electron microscopy(SEM), energy dispersive spectroscopy (EDS), dynamic light scattering (DLS), Fourier transform infrared spectroscopy(FLlR) and thermogravimetric analysis(TGA), respectively. The adsorption properties of this functional material for Lysozyme were studied by static adsorption experiments. The results show that the magnetic functional materials had nice adsorption capacity (the maximum adsorption capacity was 162.1 mg/g) and fast adsorption kinetics(the adsorption equilibrium could be reached in 150 min). The pseudo-second-order kinetic model was suitable for describing the adsorption kinetics of lysozyme on functional materials, and the adsorption process of functional materials on lysozyme was more in line with Langmuir adsorption model, indicating that adsorption is monolayer adsorption. Fe3O4@3DG@VTMO@MPS as solid phase extraction materials as solid phase extraction materials could be used for separation and enrichment of lysozyme, then combined with high performance liquid chromatography (HPLC) to detect honey in actual samples. [ABSTRACT FROM AUTHOR]

Objective To investigate the effects of growth differentiation factor-11 (GDF-11) on bone marrow endothelial progenitor cells (BM-EPC) cultured with high glucose and its possible mechanism. Methods BM-EPC were cultured in vitro and divided into the following groups: normal glucose (NG) group, high glucose (HG) group, HG+recombinant GDF-11 (rGDF-11) group and HG+rGDF-11+TGF-β receptor I inhibitor SB431542 group. Proliferation was assessed by MTT, and apoptosis of EPC were stained with Annexin V-FITC and propidium iodide (PI), and assessed by flow cytometry. The expression of Bcl-2, Bax and Cleaved-caspase 3 were detected by western blot. The phosphorylation of Smad were assessed by immunofluorescence. Data among multiple groups were compared by using one-way ANOVA and the least significant difference t test. Results Compared with the vehicle control group, Bcl-2/Bax ratio decreased, the protein levels of Cleaved-caspase 3 increased and the percentage of apoptotic EPC elevated in those groups cultured with HG [0.45±0.09 vs 1.21±0.23, 0.28±0.02 vs 0.07±0.00, (18.63±3.02)% vs (2.82±0.46)%, t=3.04, -68.06, -7.60, all P<0.05]. However, the effects were blocked by pretreated with rGDF-11. Treatment of EPC with TGF-β receptor I inhibitor SB431542 partially abolished the pro-proliferation and anti-apoptotic effects of GDF-11 (0.56 ± 0.11 vs 1.14 ± 0.07, t=4.33, P<0.05). Immunofluorescence analyses showed that Smad2/3 phosphorylation decreased in high glucose culturing. Pre-incubation with rGDF-11 restored p-Smad2 / 3 expression, however, GDF-11 mediated Smad2 / 3 activation was partially blocked by SB431542 (0.89±0.12 vs 1.21±0.12, t=-3.20,P<0.05). Conclusion GDF-11 may prevent high glucose-induced EPC apoptosis and improve proliferation through activation of TGF-β/Smad2/3 signaling pathway. [ABSTRACT FROM AUTHOR]