Antibiotic prescribing practices of medical doctors in a resource-limited setting and the influence of individual perceptions and stewardship support: a survey in three tertiary hospitals in Vietnam.

Objectives: To understand antibiotic prescribing and influencing factors to inform antimicrobial stewardship (AMS) interventions to reduce unwanted consequences of antibiotic use in hospitals in Vietnam, a lower-middle-income country in Asia. Methods: We conducted a cross-sectional study of doctors at three tertiary hospitals using non-probability convenience sampling, through a paper-based (Hospitals 1 and 2) or electronic (Hospital 3) survey. Questions included items on perceptions regarding antibiotic resistance and AMS, prescribing practices, knowledge, demographics and training. We used principal components analysis and mixed-effects models to examine practices and identify influencing factors. Results: Among 314 surveyed participants, 61%, 57% and 59% in Hospitals 1, 2 and 3, respectively, felt certain about the appropriateness of their antibiotic prescriptions. In total, 9% reported sometimes prescribing antibiotics when not needed to meet patients' expectations, and 13% reported doing so to avoid perceived complications. Higher prescribing confidence was found among those with positive perceptions about AMS (P < 0.0001), whereas negative perceptions about colleagues' practices reduced this confidence (P < 0.0001). Individual preference for branded antibiotics was associated with more unnecessary prescribing whereas having higher prescribing confidence decreased the habits of prescribing when not needed. Conclusions: This study provides important implications for design of hospital interventions to address influencing factors on antibiotic prescribing in Vietnam and similar resource-limited settings. Specific interventions should target improving knowledge through education and training for doctors, enhancing the support from the AMS team, and promoting guidelines and policies for appropriate antibiotic use in hospital.

F-free etching and ingenious construction of hydrogel layer-prepared MXene membranes for oily wastewater separation.

A strategy for the preparation of hydrogel layer MXene membranes by an F-free method was proposed. It maintained high permeance (2686.1 L m-2 h-1 bar-1) and separation efficiency (99.99%) even after 300 min of emulsion separation. The membrane resisted harsh chemical and microbiological environments and efficiently treated actual oily wastewater.

Synthesis, characterization and in vitro antiproliferative effects of isosteviol derivatives.

Nineteen isosteviol derivatives were designed and synthesized by C-16, C-19 and D-ring modifications of isosteviol. These compounds were screened for their cytotoxic activities against Hela and A549 cells in vitro. Among them, the inhibitory effect of compounds 3b and 16 on Hela cells was comparable to that of the positive control gefitinib, and the compounds 3b (IC50=7.84 ± 0.84 µM) and 7a (IC50=6.89 ± 0.33 µM) exhibited significant cytotoxicity superior to gefitinib (IC50=11.02 ± 3.27 µM) against A549 cells.

A Six-gene Prognostic Model Based on Neutrophil Extracellular Traps (NETs)-related Gene Signature for Lung Adenocarcinoma.

BACKGROUND: Lung adenocarcinoma (LUAD) is one of the most common malignant cancers. Neutrophil extracellular traps (NETs) have been discovered to play a crucial role in the pathogenesis of LUAD. We aimed to establish an innovative prognostic model for LUAD based on the distinct expression patterns of NETs-related genes. METHODS: The TCGA LUAD dataset was utilized as the training set, while GSE31210, GSE37745, and GSE50081 were undertaken as the verification sets. The patients were grouped into clusters based on the expression signature of NETs-related genes. Differentially expressed genes between clusters were identified through the utilization of the random forest and LASSO algorithms. The NETs score model for LUAD prognosis was developed by multiplying the expression levels of specific genes with their corresponding LASSO coefficients and then summing them. The validity of the model was confirmed by analysis of the survival curves and ROC curves. Additionally, immune infiltration, GSEA, mutation analysis, and drug analysis were conducted. Silencing ABCC2 in A549 cells was achieved to investigate its effect. RESULTS: We identified six novel NETs-related genes, namely UPK1B, SFTA3, GGTLC1, SCGB3A1, ABCC2, and NTS, and developed a NETs score signature, which exhibited a significant correlation with the clinicopathological and immune traits of the LUAD patients. High-risk patients showed inhibition of immune-related processes. Mutation patterns exhibited variability among the different groups. AZD3759, lapatinib, and dasatinib have been identified as potential candidates for LUAD treatment. Moreover, the downregulation of ABCC2 resulted in the induction of apoptosis and suppression of migration and invasion in A549 cells. CONCLUSION: Altogether, this study has identified a novel NET-score signature based on six novel NET-related genes to predict the prognosis of LUAD and ABCC2 and has also explored a new method for personalized chemo-/immuno-therapy of LUAD.

B Cell Tolerance and Targeted Therapies in SLE.

Systemic Lupus Erythematosus (SLE) is a chronic systemic autoimmune disease of high clinical and molecular heterogeneity, and a relapsing-remitting pattern. The disease is currently without cure and more prevalent in women. B cell tolerance and production of autoantibodies are critical mechanisms that drive SLE pathophysiology. However, how the balance of the immune system is broken and how the innate and adaptive immune systems are interacting during lupus-specific autoimmune responses are still largely unknown. Here, we review the latest knowledge on B cell development, maturation, and central versus peripheral tolerance in connection to SLE and treatment options. We also discuss the regulation of B cells by conventional T cells, granulocytes, and unconventional T cells, and how effector B cells exert their functions in SLE. We also discuss mechanisms of action of B cell-targeted therapies, as well as possible future directions based on current knowledge of B cell biology.

Anoikis-related gene signatures can aid prognosis of lung adenocarcinoma.

BACKGROUND: Lung adenocarcinoma (LUAD) is the most common subtype of lung cancer, and while advancements in diagnosis, surgery, radiotherapy, and molecular therapy have improved clinical prognosis, the long-term survival rate and quality of life of patients remain unsatisfactory. Therefore, identifying new prognostic biomarkers and potential therapeutic targets is crucial. OBJECTIVES: This study aimed to analyze the role of anoikis-related gene characteristics in LUAD. MATERIAL AND METHODS: The anoikis-related genes were obtained from the GeneCards database. Genetic expression data and clinical characteristic information were collected from The Cancer Genome Atlas (TCGA)-LUAD, and the Gene Expression Omnibus (GEO) GSE31210, GSE37745, and GSE68465 datasets. Random survival forest and least absolute shrinkage and selection operator (LASSO) models were applied to construct the risk model. An analysis of immune cell infiltration and function was performed with the scores. RESULTS: Four prognosis-related genes (TLE1, GLI2, PLK1, and BAK1) were obtained and used to construct the anoikis score. We found that the patient survival rate was higher in the low-anoikis score (LAS) group. Moreover, both the stromal and immune scores were negatively correlated with the anoikis score. With the increase of the anoikis score, the levels of natural killer cells, regulatory T cells, CD4+ T cells, CD8+ T cells, B cells, and macrophages decreased. The anoikis score had a negative regulatory relationship with the immune response, natural killer cell activation and T cell activation. The TP53 mutation was significant in LUAD patients and was present in 56% of the high-anoikis score (HAS) group and in 40% of the LAS group. CONCLUSIONS: The anoikis score was associated with poor prognosis in LUAD patients. Anoikis-related genes were associated with tumor immune dysregulation and TP53 mutation in LUAD. This study opens a new perspective for LUAD therapy.

Alterations of fecal microbiome and metabolome in pemphigus patients.

The role of gut microbiome and metabolic substances in the development of autoimmune diseases has gradually been revealed. However, the relevant gut features in pemphigus have not been well clarified. We collected stool samples from pemphigus patients and healthy controls (HCs). Metagenomic sequencing and liquid chromatography-mass spectrometry (LC/MS) metabolome sequencing were performed to analyze the compositional and metabolic alternations of the gut microbiome in pemphigus patients and HCs. We observed the reduced richness and diversity and greater heterogeneity in pemphigus patients, which was characterized by a significant decrease in Firmicutes and an increase in Proteobacteria. At the species level, Intestinal pathogenic bacteria such as Escherichia coli and Bacteroides fragilis were significantly enriched, while anti-inflammatory bacteria and butyric acid-producing bacteria were significantly reduced, which were related to clinical indicators (Dsg1/3 and PDAI). 4 species were selected by the machine learning algorithm to better distinguish pemphigus patients from healthy people. Metabolomic analysis showed that the composition of pemphigus patients was different from that of HCs. PE (18:3 (6Z,9Z, 12Z)/14:1 (9Z)) was the main metabolic substance in pemphigus and involved in a variety of metabolic pathways. While Retinol, flavonoid compounds and various amino acids decreased significantly compared with HCs. Furthermore, we found that differences in the levels of these metabolites correlated with changes in the abundance of specific species. Our study provides a comprehensive picture of gut microbiota and metabolites in pemphigus patients and suggests a potential mechanism of the aberrant gut microbiota and metabolites in the pathogenesis of pemphigus.

Global identification of natural antisense transcripts in Gossypium hirsutum and Gossypium barbadense under chilling stress.

Natural antisense transcripts (NATs) in model plants have been recognized as important regulators of gene expression under abiotic stresses. However, the functional roles of NATs in crops under low temperature are still unclear. Here, we identified 815 and 689 NATs from leaves of Gossypium hirsutum and G. barbadense under chilling stress. Among those, 224 NATs were identified as interspecific homologs between the two species. The correlation coefficients for expression of NATs and their cognate sense genes (CSG) were 0.43 and 0.37 in G. hirsutum and G. barbadense, respectively. Furthermore, expression of interspecific NATs and CSGs alike was highly consistent under chilling stress with correlation coefficients of 0.90-0.91. Four cold-associated NATs were selected for functional validation using virus-induced gene silencing (VIGS). Our results suggest that CAN1 engage in the molecular regulation of chilling stress by regulating SnRK2.8 expression. This highly conserved NAT have valuable potential for applications in breeding cold-tolerant cotton.

Anxiety and associated factors among Vietnamese students during COVID-19 pandemic: A cross-sectional study.

Mental health care for students in general, particularly anxiety, is a significant problem that needs more attention, especially during the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to describe the prevalence of anxiety and examine the associated factors among students during the COVID-19 pandemic in Vietnam. A cross-sectional study was conducted from August to September 2021 among 5730 students. An online survey was used to collect sociodemographic information, and the generalized anxiety disorder questionnaire (GAD-7) was used to assess anxiety symptoms among Vietnamese students. Results showed that the prevalence of anxiety among study participants was 16.2% (95% confidence interval [CI]: 15.3%-17.2%). Factors related to anxiety among students were gender, type of housemate, COVID-19 exposure/infection status, vaccination status, health status, academic performance, and social relationships during the COVID-19 pandemic. A significant number of students experienced anxiety during COVID-19, and this rate was related to several factors. Psychological interventions are required to support students during and after the COVID-19 pandemic and other health crises. Further studies are required to confirm our findings.

Analysis of Cognition, Protection, Psychological, and Job-search Intentions Among Medical and Nonmedical College Students During COVID-19 Epidemic.

Context: Since December 2019, medical practitioners discovered a novel coronavirus causing an acute respiratory-tract infection in some hospitals in Wuhan, Hubei Province. COVID-19 has spread globally, making it an epidemic worldwide at present. Understanding the mental-health responses of college students to COVID-19 can help a school staff to better guide students seeking education. Objective: The study aimed to explore the differences between nonmedical and medical college students during the COVID-19 epidemic in their cognitive interest about the disease, preventive behaviors, psychological effects, and job-search intentions, hoping to provide more targeted measures for virus-coping education for college students. Design: The research team conducted a cross-sectional study, using an anonymous online questionnaire. Setting: The study took place at Shanghai, China. Participants: Participants were 1648 college students studying different specialties in various provinces of China, 485 nonmedical students and 1163 medical students. Outcome Measures: The survey's questions covered the respondents': (1) general demographic characteristics, (2) cognitive interest and knowledge about COVID-19 and its infectiousness as well as efforts at active learning about infectious diseases and viruses, (3) awareness of precautionary behaviors against COVID-19, (4) effects on mental health, and (5) effects on job-search intentions. The research team used descriptive statistics and Chi-square tests to analyze the survey data. Results: Among nonmedical students: (1) 297 participants (61.2%) were interested in learning about COVID-19, (2) 321 participants (66.2%) took the initiative to learn about the virus, (3) 301 participants (62.1%) took the initiative to learn about infectious disease, and (4) 151 participants (31.1%) watched medical-themed movies or TV series about COVID-19. Among medical students, the corresponding proportions were 772 participants (66.4%), 855 participants (73.5%), 791 participants (68.1%), and 791 participants (68.1%), respectively. Among nonmedical students, 223 participants (46.0%) had N95 masks available, 429 participants (88.5%) had disinfectant supplies available, 271 participants (55.9%) wore goggles in public places, 75 participants (15.5%) chose public transportation, and 77 participants (15.9%) were exposed to public places in the week prior to the survey. Among medical students, the corresponding proportions were 470 participants (40.4%), 935 participants (80.4%), 575 participants (49.4%), 243 participants (20.9%), and 297 participants (25.5%), respectively. Furthermore, COVID-19 had a stronger effect on medical students' psychology and job-search ambitions. Conclusions: The news about COVID-19 piqued the interest of medical students. Nonmedical students had stronger protective behavior than medical students. The COVID-19 outbreak had a significant influence on medical students' lives, studies, and moods. In addition, COVID-19 had a greater impact on the job-search intentions of medical students.

Employment Intention of Chinese Medical Students During the COVID-19 Epidemic: A Cross-Sectional Survey.

Context: In the process of combating the coronavirus disease 2019 (COVID-19) epidemic, medical personnel were at the forefront of the fight. As the future medical workforce, medical students often experienced firsthand how their seniors and teachers had to commit to working hard in combating the epidemic. Many were directly involved in the front line of the fight and that experience could easily have affected their intention to seek employment in a medically related career. Objective: The study intended to evaluate the impact of the COVID-19 pandemic on Chinese medical students' employment intentions and the factors associated with them to put forward relevant suggestions to provide a basis for medical education in the future. Design: The research team conducted a cross-sectional study, using an anonymous online questionnaire. Setting: The study took place in many provinces and cities in China and was conducted in an online questionnaire. Participants: Participants were 1114 college students studying clinical medicine, college students studying nursing, and students interning during standardized resident training, medical interns. Outcome Measures: The participants completed a self-administered questionnaire, which investigated their psychological statuses related to anxiety and depression as well as COVID-19's impact on their intentions related to job searches, regarding their willingness to engage in clinical or basic research in epidemic-related specialties and epidemic-related work. Results: Compared to college students studying clinical medicine, the employment intentions of nursing students and medical interns were more vulnerable to the epidemic. Females and nursing students were more reluctant to choose clinical work, and the choice was associated with depression. Nursing college students and medical interns were significantly less willing to engage in infection medicine, respiratory medicine, and intensive care medicine (all P < .001). Medical students with a bachelor's degree and postgraduate degrees were significantly less willing to engage in infection medicine and respiratory medicine (all P < .001), but medical students from regions with stable epidemics were more willing to engage in intensive care medicine. Medical students with a bachelor's degree were significantly less likely to be involved in epidemiology-related work than undergraduate students, and students from severe epidemic regions were significantly less willing to work in isolation wards or to go to Wuhan as volunteers. Conclusions: Participants' psychological statuses related to anxiety and depression, genders, degrees, current educational statuses, and regions affected employment intentions during the epidemic.

Naoxintong Capsule for Secondary Prevention of Ischemic Stroke: A Multicenter, Randomized, and Placebo-Controlled Trial.

OBJECTIVE: To examine whether the combination of Naoxintong Capsule with standard care could further reduce the recurrence of ischemic stroke without increasing the risk of severe bleeding. METHODS: A total of 23 Chinese medical centers participated in this trial. Adult patients with a history of ischemic stroke were randomly assigned in a 1:1 ratio using a block design to receive either Naoxintong Capsule (1.2 g orally, twice a day) or placebo in addition to standard care. The primary endpoint was recurrence of ischemic stroke within 2 years. Secondary outcomes included myocardial infarction, death due to recurrent ischemic stroke, and all-cause mortality. The safety of drugs was monitored. Results were analyzed using the intention-to-treat principle. RESULTS: A total of 2,200 patients were enrolled from March 2015 to March 2016, of whom 143 and 158 in the Naoxintong and placebo groups were lost to follow-up, respectively. Compared with the placebo group, the recurrence rate of ischemic stroke within 2 years was significantly lower in the Naoxintong group [6.5% vs. 9.5%, hazard ratio (HR): 0.665, 95% confidence interval (CI): 0.492-0.899, P=0.008]. The two groups showed no significant differences in the secondary outcomes and safety, including rates of severe hemorrhage, cerebral hemorrhage and subarachnoid hemorrhage (P>0.05). CONCLUSION: The combination of Naoxintong Capsule with standard care reduced the 2-year stroke recurrence rate in patients with ischemic stroke without increasing the risk of severe hemorrhage in high-risk patients. (Trial registration No. NCT02334969).

Analyzing the influence of COVID-19 epidemic on the employment intention of resident physicians in China.

INTRODUCTION: To investigate the effects and influencing factors of the COVID-19 epidemic on the employment intention of resident physicians in China. METHODOLOGY: 409 questionnaires were statistically analyzed after removing the missing values. We used the Chi-Square test for single-factor analysis and logistic regression analysis for multivariate analysis. The questions include the residents' employment intention and their willingness to engage in epidemic-related subspecialties and participate in epidemic-related work. RESULTS: Residents of severe and high-risk epidemic regions had much lower employment intentions than those of stable epidemic regions (OR = 1.917, 95% CI: 1.024, 3.591, p = 0.042). The higher the Center for Epidemiologic Studies Depression Scale (CES-D) score, the more susceptible was the resident's employement intention (OR = 1.085, 95% CI: 1.044, 1.128, p < 0.001). Residents from severe and high-risk epidemic regions were more willing to participate in clinical work (OR = 4.263, 95% CI: 1.892, 9.604, p < 0.001), and the higher the CES-D score, the lower was the proportion of residents willing to choose clinical work (OR = 0.941, 95% CI: 0.893, 0.992, p = 0.023). Residents from severe epidemics and high-risk provinces were less willing to participate in respiratory medicine (χ2 = 5.070, p = 0.027) and critical care medicine (χ2 = 7.046, p = 0.011). Compared to residents with bachelor's degrees, residents with master's and doctoral degrees were less willing to participate in isolation wards (OR = 1.831, 95% CI: 1.122, 2.990, p = 0.016). Residents in epidemic-related current rotation departments were less willing to go to Wuhan as volunteers (OR = 2.197, 95% CI: 1.110, 4.347, p = 0.024). CONCLUSIONS: The COVID-19 outbreak had a negative impact on the job intentions of Chinese residents in general.

Preparation and Application of Decellularized ECM-Based Biological Scaffolds for Articular Cartilage Repair: A Review.

Cartilage regeneration is dependent on cellular-extracellular matrix (ECM) interactions. Natural ECM plays a role in mechanical and chemical cell signaling and promotes stem cell recruitment, differentiation and tissue regeneration in the absence of biological additives, including growth factors and peptides. To date, traditional tissue engineering methods by using natural and synthetic materials have not been able to replicate the physiological structure (biochemical composition and biomechanical properties) of natural cartilage. Techniques facilitating the repair and/or regeneration of articular cartilage pose a significant challenge for orthopedic surgeons. Whereas, little progress has been made in this field. In recent years, with advances in medicine, biochemistry and materials science, to meet the regenerative requirements of the heterogeneous and layered structure of native articular cartilage (AC) tissue, a series of tissue engineering scaffolds based on ECM materials have been developed. These scaffolds mimic the versatility of the native ECM in function, composition and dynamic properties and some of which are designed to improve cartilage regeneration. This review systematically investigates the following: the characteristics of cartilage ECM, repair mechanisms, decellularization method, source of ECM, and various ECM-based cartilage repair methods. In addition, the future development of ECM-based biomaterials is hypothesized.

[Effects of water level variations on survival, morphological phenotype and responsiveness of tadpoles to phytohemagglutinin]. / æ°´ä½å˜åŒ–å½±å“èŒèšªå­˜æ´»ã€å½¢æ€è¡¨åž‹å’Œæ¤ç‰©è¡€å‡ç´ ååº”.

To investigate the responses of morphological and physiological characteristics in tadpoles of Pelophylax nigromaculatus to various water levels, a total of 480 tadpoles with similar sizes were treated with rapid, moderate and slow desiccation. Both the metamorphosis duration and average metamorphosis survival rate of specific developmental stages were counted. Their body and internal organ sizes, as well as the responsiveness to phytohemagglutinin (PHA-P) of froglets were measured after complete metamorphosis. The results showed that the metamorphosis duration of tadpoles in the control group was the longest. The average metamorphosis survival rate of different treatment groups ranged from 72.5% to 90.8%, which was the highest in the control group and the lowest in the rapid desiccation group. Body weight (BW) and body length (BL) of froglets in control and slow desiccation groups were significantly higher than those of moderate or rapid desiccation groups. Body width, ratio of BW to BL, carcass wet weight and the wet weight index of lung and fat body were the lowest in rapid desiccation group. There was no significant difference in the wet weight index of heart, spleen, kidneys and digestive organs, as well as the length index of different segments of whole digestive tract between groups. The maximal response value of froglets to PHA-P appeared at 3 h after injection in different treatments, which was significantly higher in moderate and slow desiccation groups than the control group. There was no significant difference between rapid desiccation group and any other groups. The tadpoles of P. nigromaculatus might accelerate the metamorphosis developmental process to cope with desiccation stress, accompanying with decreased atrophic body size and weakened cell-mediated immunity, which would harm tadpoles to successfully land.

Synthesis, antitumor and antibacterial activities of cordycepin derivatives.

Twelve novel cordycepin derivatives were designed and synthesized with modification at positions of 2', 5'-hydroxyl and N6 amino groups of cordycepin. The results showed that the inhibitory activities of 3, 4b, 6c and 6d on A549 were comparable to the positive control gefitinib, and the inhibitory activity of 6a on A549 was better than that of gefitinib. Also, the inhibitory activities of twelve cordycepin derivatives against E. coli 1924, S. aureus 4220 and S. mutans 3289 were studied. Among them, 4b showed certain inhibitory on S. mutans 3289, while 6b showed certain inhibition on S. aureus 4220.

Cracked-earth-like titanium carbide MXene membranes with abundant hydroxyl groups for oil-in-water emulsion separation.

Membrane separation technology is one of the best methods to deal with wastewater released from oil spills and industrial wastewater. Therefore, we designed and prepared hydroxyl-rich titanium carbide MXene materials and filtered them onto a commercial polyvinylidene fluoride substrate membrane to obtain a cracked-earth-like MXene membrane with abundant hydroxyl groups and excellent underwater wettability. The underwater oil contact and sliding angles were approximately 157° and less than 3°, respectively. Moreover, the membrane effectively separated a variety of surfactant-stabilized stable emulsions with a high permeation flux of up to 6385 L m-2h-1 bar-1 and offered adequate performance after five cycles of the separation experiment. Additionally, the membrane exhibited remarkable resistance toward corrosive chemicals without any decrease in its underwater wettability performance. For example, the membrane was used to separate the emulsions containing alkali, salt, and acid. This study provides a new strategy to resolve the oily wastewater disposal problem by fabricating a cracked-earth-like MXene membrane with abundant hydroxyl groups.

Analysis of 131I radiation internal exposure in nuclear medicine staff of eight hospitals in Guangdong Province / 中国职业医学

@#Abstract: Objective （ ） To evaluate the internal exposure levels and risk in nuclear medicine workers NMWs engaged in Methods radionuclide therapy in Guangdong Province. A total of 61 NMWs from eight hospitals in Guangdong Province were selected as the study subjects using the convenient sampling method. The 0.364 MeV full energy peak efficiency was detected in （ ） in vitro ， - deltoid muscle of right upper arm as background and thyroid gland by direct measurement method and the iodine 131 （131 ） Results ，131 I activity in thyroid gland was calculated to evaluate the internal irradiation level. Among the 61 NMWs I was ， detected in the thyroid gland of four nuclear medical staffs in three hospitals and the detection rate was 6.6%. The median and - ［M（ P-P ）］ 131 （ - ） 0 100 percentile 0 100 of thyroid I activity were 42.9 35.1 47.1 Bq. When assuming that the monitoring period was ， M（ P-P ） （ - ） ， 30 days the 0 100 of single committed effective dose in thyroid gland was 0.014 0.011 0.015 mSv and the annual dose （ - ） Conclusion of internal irradiation was 0.162 0.132 0.180 mSv/a. The internal exposure of NMWs in the eight hospitals in （ ） ， Guangdong Province meets the annual effective dose limits ≤20.000 mSv/a . However it is necessary to pay attention to the internal radiation protection of NMWs and take reasonable protective measures to reduce the internal exposure risk of NMWs.

[A novel alkaloid from Corydalis tomentella].

The chemical constituents in the ethyl acetate extract of Corydalis tomentella was isolated and purified with normal and reversed phase silica gel column chromatography, Sephadex LH-20, MCI, and semi-preparative HPLC. The compound structures were identified based on spectroscopic experiments and reported papers. Finally, eighteen compounds(1-18) were obtained from C. tomentella, including 17 alkaloids and 1 terpenoid. Among them, compound 1(tomentellaine A) was a novel alkaloid. Compounds 2-5, 7-14, and 16-18 were isolated from this plant for the first time.

Risk factors for recurrent positive results of the nucleic acid amplification test for COVID-19 patients: a retrospective study.

Positive retests of COVID-19 represent a public health concern because of the increased risk of transmission. This study explored whether factors other than the nucleic acid amplification test (NAAT) contribute to positive retest results. Patients with COVID-19 admitted to the Guanggu district of the Hubei Maternal and Child Health Hospital between February 17 and March 28, 2020, were retrospectively included. The patients were grouped into the negative (n = 133) and positive (n = 51) retest groups. The results showed that the proportion of patients presenting with cough was higher (P < 0.001) and the proportion of patients with dyspnea was lower (P = 0.018) in the positive than in the negative retest group. The positive retest group showed shorter durations between symptom onset and hospitalization (P < 0.001) and symptom onset and the first positive NAAT (P = 0.033). The positive retest group had higher basophil counts (P = 0.023) and direct bilirubin (P = 0.032) and chlorine concentrations (P = 0.023) but lower potassium concentrations (P = 0.001) than the negative retest group. Multivariable regression analysis showed that coughing (OR = 7.59, 95% CI 2.28-25.32, P = 0.001) and serum chloride concentrations (OR = 1.38, 95% CI 1.08-1.77, P = 0.010) were independently associated with a positive retest result. Coughing and serum chloride concentrations were independent risk factors for positive NAAT retest results. Patients with a hospital stay of < 2 weeks or a short incubation period should stay in isolation and be monitored to reduce transmission. These results could help identify patients who require closer surveillance.