The wide use of crystalline silicon solar cells in the field of new energy is an important boost for China to achieve the environmental protection goal as soon as possible. However, the production and manufacturing processes of these cells give rise to various occupational hazards at workplace, thus posing health risks to workers. This review provided an overview of production processes of crystalline silicon solar cells, the characteristics of occupational health hazards (productive dust; physical factors, productive toxicant) and proposed occupational protection suggestions.

The wide use of crystalline silicon solar cells in the field of new energy is an important boost for China to achieve the environmental protection goal as soon as possible. However, the production and manufacturing processes of these cells give rise to various occupational hazards at workplace, thus posing health risks to workers. This review provided an overview of production processes of crystalline silicon solar cells, the characteristics of occupational health hazards (productive dust; physical factors, productive toxicant) and proposed occupational protection suggestions.

Medical image segmentation based on deep learning has become a powerful tool in the field of medical image processing. Due to the special nature of medical images, image segmentation algorithms based on deep learning face problems such as sample imbalance, edge blur, false positive, false negative, etc. In view of these problems, researchers mostly improve the network structure, but rarely improve from the unstructured aspect. The loss function is an important part of the segmentation method based on deep learning. The improvement of the loss function can improve the segmentation effect of the network from the root, and the loss function is independent of the network structure, which can be used in various network models and segmentation tasks in plug and play. Starting from the difficulties in medical image segmentation, this paper first introduces the loss function and improvement strategies to solve the problems of sample imbalance, edge blur, false positive and false negative. Then the difficulties encountered in the improvement of the current loss function are analyzed. Finally, the future research directions are prospected. This paper provides a reference for the reasonable selection, improvement or innovation of loss function, and guides the direction for the follow-up research of loss function.
Algorithms ; Image Processing, Computer-Assisted

Computer-aided diagnosis (CAD) systems play a very important role in modern medical diagnosis and treatment systems, but their performance is limited by training samples. However, the training samples are affected by factors such as imaging cost, labeling cost and involving patient privacy, resulting in insufficient diversity of training images and difficulty in data obtaining. Therefore, how to efficiently and cost-effectively augment existing medical image datasets has become a research hotspot. In this paper, the research progress on medical image dataset expansion methods is reviewed based on relevant literatures at home and abroad. First, the expansion methods based on geometric transformation and generative adversarial networks are compared and analyzed, and then improvement of the augmentation methods based on generative adversarial networks are emphasized. Finally, some urgent problems in the field of medical image dataset expansion are discussed and the future development trend is prospected.
Humans ; Diagnosis, Computer-Assisted ; Diagnostic Imaging ; Datasets as Topic

Objective:To study the distribution and antibiotics resistance of the main pathogens of neonatal purulent meningitis in different regions of China.Methods:A retrospective descriptive clinical epidemiological study was conducted in children with neonatal purulent meningitis which admitted to 18 tertiary hospitals in different regions of China between January 2015 to December 2019. The test results of blood and cerebrospinal fluid, and drug sensitivity test results of the main pathogens were collected. The distributions of pathogenic bacteria in children with neonatal purulent meningitis in preterm and term infants, early and late onset infants, in Zhejiang Province and other regions outside Zhejiang Province, and in Wenzhou region and other regions of Zhejiang Province were analyzed. The chi-square test was used for statistical analysis.Results:A total of 210 neonatal purulent meningitis cases were collected. The common pathogens were Escherichia coli ( E. coli)(41.4%(87/210)) and Streptococcus agalactiae ( S. agalactiae)(27.1%(57/210)). The proportion of Gram-negative bacteria in preterm infants (77.6%(45/58)) with neonatal purulent meningitis was higher than that in term infants (47.4%(72/152)), and the difference was statistically significant ( χ2=15.54, P=0.001). There were no significant differences in the constituent ratios of E. coli (36.5%(31/85) vs 44.8%(56/125)) and S. agalactiae (24.7%(21/85) vs 28.8%(36/125)) between early onset and late onset cases (both P>0.05). The most common pathogen was E. coli in different regions, with 46.7%(64/137) in Zhejiang Province and 31.5%(23/73) in other regions outside Zhejiang Province. In Zhejiang Province, S. agalactiae was detected in 49 out of 137 cases (35.8%), which was significantly higher than other regions outside Zhejiang Province (11.0%(8/73)). The proportions of Klebsiella pneumoniae, and coagulase-negative Staphylococcus in other regions outside Zhejiang Province (17.8%(13/73) and 16.4%(12/73)) were both higher than those in Zhejiang Province (2.9%(4/137) and 5.1%(7/137)). The differences were all statistically significant ( χ2=14.82, 12.26 and 7.43, respectively, all P<0.05). The proportion of Gram-positive bacteria in Wenzhou City (60.8%(31/51)) was higher than that in other regions in Zhejiang Province (38.4%(33/86)), and the difference was statistically significant ( χ2=6.46, P=0.011). E. coli was sensitive to meropenem (0/45), and 74.4%(32/43) of them were resistant to ampicillin. E. coli had different degrees of resistance to other common cephalosporins, among which, cefotaxime had the highest resistance rate of 41.8%(23/55), followed by ceftriaxone (32.4%(23/71)). S. agalactiae was sensitive to penicillin, vancomycin and linezolid. Conclusions:The composition ratios of pathogenic bacteria of neonatal purulent meningitis are different in different regions of China. The most common pathogen is E. coli, which is sensitive to meropenem, while it has different degrees of resistance to other common cephalosporins, especially to cefotaxime.

Hepatitis B virus core protein can self-assemble into icosahedral symmetrical viral-like particles (VLPs) in vitro, and display exogenous sequences repeatedly and densely on the surface. VLPs also have strong immunogenicity and biological activity. When the nanoparticles enter the body, they quickly induce specific humoral and cellular immune responses to exogenous antigens. In this study, we designed an HBc-VLPs that can be coupled with antigens at specific sites, and developed a set of efficient methods to prepare HBc-VLPs. Through site-specific mutation technology, the 80th amino acid of peptide was changed from Ala to Cys, a specific cross-linking site was inserted into the main immunodominant region of HBc-VLPs, and the prokaryotic expression vector pET28a(+)-hbc was constructed. After expression and purification, high purity HBc(A80C) monomer protein was assembled into HBc-VLPs nanoparticles in Phosphate Buffer. The results of particle size analysis show that the average particle size of nanoparticles was 29.8 nm. Transmission electron microscopy (TEM) showed that HBc-VLPs formed spherical particles with a particle size of about 30 nm, and its morphology was similar to that of natural HBV particles. The influenza virus antigen M2e peptide as model antigen was connected to Cys residue of HBc-VLPs by Sulfo-SMCC, an amino sulfhydryl bifunctional cross-linking agent, and M2e-HBc-VLPs model vaccine was prepared. The integrity of HBc-VLPs structure and the correct cross-linking of M2e were verified by cell fluorescence tracing. Animal immune experiments showed that the vaccine can effectively stimulate the production of antigen-specific IgG antibody in mice, which verified the effectiveness of the vaccine carrier HBc-VLPs. This study lays a foundation for the research of HBc-VLPs as vaccine vector, and help to promote the development of HBc-VLPs vaccine and the application of HBc-VLPs in other fields.
Animals ; Hepatitis B Core Antigens ; genetics ; immunology ; Immunity, Cellular ; immunology ; Immunoglobulin G ; blood ; Mice ; Mice, Inbred BALB C ; Vaccines, Virus-Like Particle ; genetics ; immunology

Objective? To analyze the mediating and modulating effects of self-efficacy between health literacy and quality of life in patients with esophagus cancer receiving chemotherapy. Methods? Totally 105 patients receiving chemotherapy for esophagus cancer in Heping Hospital Affiliated to Changzhi Medical University from January 2015 to December 2017 were selected by convenient sampling and investigated with General Self Efficacy Scale (GSES), Health Literacy Management Scale (HeLMS) and Spitzer Quality of Life Index (SQLI). Pearson correlation analysis was used to analyze the correlation between the patients' self-efficacy, health literacy and quality of life, and regression analysis was used to mediating and modulating effects between the variables. Results? The average self-efficacy score, health literacy score and quality of life score of the 105 patients were (2.38±0.47), (86.65±12.29) and (4.94±0.55), respectively. Pearson correlation analysis showed that self-efficacy was positively correlated with health literacy and quality of life (r=0.517, 0.462; P＜0.05). Self-efficacy showed mediating effects between health literacy and quality of life in the patients with esophagus cancer, which accounted for 34.82% in the total effect. Regression analysis showed that the regression coefficient of the interacting "health literacy×self-efficacy" was statistically significant (β'=0.015,t=2.718;P＜ 0.01), whose mediating effect was significant (ΔR2=0.018, P＜ 0.01). Conclusions? Self-efficacy has mediating and modulating effects between health literacy and quality of life in patients receiving chemotherapy for esophagus cancer.

Objective To explore the risk factors of dysphagia in patients with cardiac surgery, so as to provide a basis for clinical nursing. Methods From January 2014 to June 2016, we collected data from 158 patients with cardiac surgery in Heping Hospital Affiliated of Changzhi Medical College. All of the patients were divided into the group of dysphagia (n=60) and the group of normal deglutition (n=98). We compared the sexes, ages, body mass index (BMI), smoking history, time of tracheal intubation, types of surgery, family history of heart disease, previous history of cardiac surgery, New York Heart Association (NYHA) classification, European System for Cardiac Operative Risk Evaluation (EuroSCORE), bed and oxygen uptake after surgery, intra-operative transesophageal echocardiography, natriuretic peptide application and mechanical assistance after surgery between two groups. Multiple Logistic was used to analyze the risk factors of dysphagia after surgery. Results There were no statistical differences in the BMI, smoking history, family history of heart disease, bed and oxygen uptake after surgery, intra-operative transesophageal echocardiography, natriuretic peptide application and mechanical assistance after surgery as well as of previous history of cardiac surgery of patients between the group of dysphagia and the group of normal deglutition (P＞0.05);however, there were significant differences among patients with different ages,gender, NYHA classification, EuroSCORE, time of tracheal intubation (P＜ 0.05). Multiple logistic analysis showed that the risk factors of dysphagia after cardiac surgery included the ages equal or greater than 70 years old, Ⅲ-Ⅳ for the NYHA classification, 3-6 for the score of EuroSCORE, time of tracheal intubation equal or greater than 12 hours (P＜ 0.05). Conclusions Health care providers should pay attention to the influencing factors of dysphagia after cardiac surgery involving ages, NYHA classification, score of EuroSCORE, time of tracheal intubation.

Objective To explore the effect of total saponins from Medicago polymorpha (TSMP) on glucose metabolism in type 2 diabetes mellitus (T2DM) rats and its possible mechanism.Methods T2DM rats were established by feeding with fat diets and intraperitoneally injecting with STZ 30 mg/kg.The rats were divided into control group,model group,metformin group (0.2 g/kg),TSMP high dose group (1.4 g/kg) and TSMP low dose group (0.7 g/kg),which were administrated for four weeks.At the end of administration,blood samples were collected to determine insulin resistance index (IRI),levels of fasting blood glucose (FBG),glycosylated hemoglobin (HbAlc),hepatic glycogen,interleukin (IL)-1 β,tumor necrosis factor (TNF)-α,free fatty acids (FFA) and Leptin,and activities of pyruvate kinase (PK),hexokinase (HK),glucose-6-phosphatase (G-6-Pase),fructose-1,6-bisphosphatase and glucokinase (GK).Western blot was used to detect the expression levels of G-6-Pase and phosphoenolpyruvate carboxykinase (PEPCK) proteins.Results Compared withthe model group,high dose (1.4 g/kg) TSMP decreased IRI,levels of FBG,HbA1 c,IL-1β,TNF-α,FFA and Leptin,and activities of G-6-Pase and fructose-1,6-bisphosphatase in T2DM rats (P＜ 0.05),while increased level of hepatic glycogen,and activities of PK,HK and GK (P＜0.05).Moreover,high dose (1.4 g/kg) TSMP down-regulated expression levels of G-6-Pase and PEPCK protein in liver tissues.Conclusion Chronic administration of TSMP can improved glucose homeostasis in T2DM rats,which might be related to promoting utilization of glucose,and alleviating inflammatory and insulin resistance.

TheMeridian and Acupoint Science is a basic course in the major of acupuncture-moxibustion and tuina. We applied target-guided teaching method in teaching this course to evoke student's interest in studyingMeridian and Acupoint Science through initiative guidance, and boost student's initiative and enthusiasm by exhibiting the teaching targets. During the practice, we emphasized the specification of each unit target, around which we adopted various methods; meanwhile, we also focused on prompt evaluation, based on which necessary adjustments would be made to approach the targets. Teachers should act as guider, maintainer and promoter in class, rather than transmitter, to help students to study positively rather than passively listen. Via this kind of teaching reform, students not only obtained knowledge, but also enhanced their capability and feelings.