BACKGROUND: Skin reproducing membrane is a biomaterial used directly in contact with skin defects, so its toxicity to the body must be taken into consideration. OBJECTIVE: To systematical y evaluate the biocompatibility of skin reproducing membrane of medical fibroin. METHODS: Skin irritation test: the skin defect of New Zealand white rabbit was covered with the skin reproducing membrane of medical fibroin, formaldehyde or normal saline, respectively, and erythema and edema were observed at 24 and 72 hours after treatment. Acute systematic toxicity test: the mice were given extracts of skin reproducing membrane of medical fibroin, phenol and normal saline via tail vein injection; then status of mice, toxicity grade and death were recorded at 24, 48 and 72 hours after injection. Cytotoxicity test: L-929 cel s were co-cultured with 100%, 50%, 25%, 10% skin reproducing membrane of medical fibroin extracts, and absorbance values were detected by ultraviolet spectrophotometry at 2, 4 and 7 days after culture, as wel as by MTT assay after 48 hours of culture, respectively. Besides, L-929 cel s were co-cultured with 100% skin reproducing membrane of medical fibroin extracts, and mRNA expression of fibronectin was determined by qPCR technology after 48-hour culture. RESULTS AND CONCLUSION: Skin reproducing membrane of medical fibroin has no adverse reaction, acute cytotoxicity, skin irritation and systemic toxicity, and additional y, it does not affect mRNA expression of fibronectin. In general, skin reproducing membrane of medical fibroin has good biocompatibility.

Objective To investigate the graduate students' mental pressure after the full im-plementation of the charging system and explore effective countermeasures of alleviating the psycho-logical pressure. Methods 413 full-time graduate students of Grade 2014 were randomly selected in a university of Shandong province. The graduate students' psychological pressure scale and self-designed questionnaire survey were used. The data were analyzed using SPSS 17.0 software, statistical descrip-tion of the survey data, independent sample t test, ANOVA. Results ①The psychological pressure of full-time graduate students at their own expense was in themedium pressure level; ②The economic pressure and academic pressure of the male graduate students were higher than those of the female graduate students (P=0.000,P=0.042), the rural economic pressures were greater than urban students graduate students graduate students (P=0.000); Professional graduate economic pressures were greater than academic graduate students (P=0.027);There is difference in the pressure of interpersonal commu-nication among different majors (P=0.016); ③78.75% (315/400) of the graduate students tuition fees, living expenses were mainly from their parents and the national and school awards; ④The percentage of those who completely agreed with the following view: full charge than at public expense is more advantageous to graduate education, comprehensive charge is advantageous to the education career development and comprehensive charge embodies the fairness of education was 84.75% (339/400), 71.25% (285/400) and 68.00% (272/400). Conclusion The full-time graduate students at their own expense have a more rational understanding of the charging policy; economic and academic pressures are the two outstanding pressure sources of the graduate students at the present stage. Graduate should improve their ability to cope with stress, and government and schools should take various measures to help students relieve stress.

Objective To evaluate the contraception efficacy, mode of bleeding, side effects and other positive effects of drospirenone-ethinylestradiol (Yasmin) in healthy Chinese women. Methods This was a multicenter, randomized, control study of 768 healthy Chinese women who consulted about contraception. The subjects were randomized into Yasmin group (30 μg ethinylestradiol plus 3 mg drospirenone, 573 cases) or desogestrel group (30 μg ethinylestradiol plus 150 μg desogestrel, 195 cases) with the ratio of 3: 1. Each individual was treated for 13 cycles. Further visits were required at cycle 4, cycle 7, cycle 10 and cycle 13 of treatment. Weight, height, body mass index were evaluated at each visit. The menstrual distress questionnaire (MDQ) was given to the women at baseline, visit 3 (cycle 7) and visit 5 (after cycle 13). Results The values of basal features were similar between two groups (P> 0.05). The Pearl index (method failure) of Yasmin was 0. 208/hundred women year which was lower than that of desogestrel (0. 601/hundred women year). The mode of bleeding was similar between two groups after trial without showing any significant difference. According to MDQ subscale, the improvement of water retention and increasing appetite during inter-menstrual period and water retention and general well-being during menstrual period in the Yasmin group ( -0. 297, -0. 057, 0. 033, 0. 150 respectively) was more obvious than that in the desogestrel group ( - 0. 108, 0. 023, 0. 231, - 0. 023 respectively) with a significant difference (P < 0. 05 ). Some other values which improved in beth two groups, especially the improvement of breast tenderness and pain and skin abnormality in Yasmin group (18.0%, 89/494; 12. 6%, 62/494) was more distinct than that in desogestrel group (11.3%, 19/168; 5.4%, 9/168). The mean weight increased in desogestrel group (0. 57 kg) while it decreased in Yasmin group ( -0. 28 kg) with a significant difference (P < 0. 01 ). Conclusions Both Yasmin and desogestrel have good efficacy on contraception and similar modes of menstrual bleeding. Yasmin is better than desogestrel in terms of weight control and premenstrual syndrome of oral contraceptive.

Objective:To evaluate the value of conventional ultrasound, shear wave elastic parameters and immunohistochemistry in predicting axillary lymph node metastasis of breast cancer.Methods:The ultrasonographic features and pathological results of 172 masses in 152 breast cancer patients who underwent surgery in the First Affiliated Hospital of Shihezi University Medical College from May to October 2020 were analyzed retrospectively. The patients were divided into metastatic group and non-metastatic group according to the status of axillary lymph nodes. The conventional ultrasound characteristics, shear wave velocity (SWV) and immunohistochemical indexes (ER, PR, HER-2, Ki-67) of 2 groups of breast cancer masses were analyzed. Finally, the parameters with statistically significant difference between groups were selected and the Logistic regression model was established.Results:There were significant differences in the aspect ratio, calcification, SWVmean and HER-2 expression between metastatic group and non-metastatic group (all P<0.05). A prediction model was constructed with aspect ratio >1, calcification, high SWVmean and HER-2(+ ). The area under receiver operating characteristic curve (AUC) of the subjects was 0.891, which was larger than the single parameter (all P<0.05), and was in good agreement with pathological results (Kappa=0.731). Conclusions:The joint prediction model can be used to predict the status of lymph nodes, and the axillary lymph node metastasis is more likely to occur in breast cancer with the aspect ratio >1, calcification, high SWVmean and HER-2(+ ).

Objective To establish a Nomogram predictive model for Neonatal Sepsis(NS)based on the general characteristics and initial complete blood count of neonates.Methods Retrospective analysis was conducted on the clinical data of newborns who were admitted for the first time to NICU and completed blood routine examination after admission in the MIMIC Ⅲ database.The LASSO-Logistic regression was used to investigate the prediction factors of NS,and then Nomogram prediction model was established.Internal validation was performed using boot-strap resampling with 1000 iterations.External validation of the model was performed using the data from newborns admitted to the First Affiliated Hospital of Zhengzhou University.We evaluated the predictive performance by Area Under the Receiver Operating Characteristic Curve(AUROC),C-index,calibration curve,and decision curve analysis(DCA).Results Among the 3,001 neonates,185 were diagnosed with NS.The Nomogram model was con-structed based on indicators such as respiratory distress syndrome,gestational age,birthweight,and initial hemato-logical parameters(red blood cell count,white blood cell count,lymphocyte percentage,neutrophil percentage),exhibiting good predictive performance with an AUROC of 0.860.Satisfactory predictive abilities were confirmed through both internal and external validation.Conclusion This study developed and validated a well-performing Nomogram prediction model.With simple parameters,it can help clinicians identify newborns at high risk early.