BACKGROUND: Previous studies have confirmed that nano-hydroxyapatite/collagen (nHAC) and mesenchymal stem cells for repair of bone defect have the ability of bone formation in vivo. OBJECTIVE: To observe the effects of vascular endothelial growth factor (VEGF) and bone marrow mesenchymal stem cells (BMSCs), nHAC composite in the repair of femoral defect in rats. METHODS: Sprague-Dawley rat models of middle part of the femur defect were established and randomly assigned to two groups. Control group was implanted with BMSCs/nHAC composite. Experimental group was implanted with VEGF/BMSCs/nHAC composite. At 2, 4 and 8 weeks postoperation, imaging and histology observation of femoral samples were performed. At 8 weeks postoperation, scanning electron microscopy was performed in new bony callus environment. RESULTS AND CONCLUSION: nHAC composite implantation in the rats did not show rejection or inflammatory reaction. Moreover, bone formed rapidly using VEGF and BMSCs, nHAC composite, which exhibited better bone regeneration capacity compared with BMSCs/nHAC composite. The way of ossification mainly was endochondral ossification. It is presumed that VEGF promoted the formation of local microvessels, differentiation and proliferation of osteoblasts, speeded up the speed of endochondral ossification, shortened bone repair time, and elevated the quality and velocity of osteanagenesis.

Objective Folate receptors ( FRs) , overexpressed on the surface of a variety of tumor cells , are potential targets for tumor targeting therapy .This study aimed to prepare an FR-mediated drug nanocarrier with folate conjugated pullulan acetate ( FPA) to target chemotherapeutic agents to FR-overexpressed tumor cells and investigate its tumor-suppressing effect in vitro. Methods The cytotoxicity of epirubicin-loaded FPA nanoparticles ( FPA/EPI NP) against HepG2 and Hela cells was evaluated by MTS assay.The HepG2 and Hela cells were divided into five groups to be treated with NPs (NP control), chlorpromazine, chloro-quine, amiloride, and folate, respectively, followed by detection of the fluorescence intensity by flow cytometry . Results FPA/EPI NP was successfully formulated into NPs , with the mean particle size of (268.5 ±12.0) nm, by dialysis with an almost spherical shape . The drug-loading rate and entrapment rate of FPA/EPI NP were (6.45 ±1.04) and (72.45 ±11.50) %, respectively.The survival rates of the HepG2 and Hela cells were both >95%after 24 hours of incubation with FPA NP at 5, 40, 200, 400 and 1000μg/mL and 90.0%after 72 hours.The survival rates of the HepG2 cells treated with 5, 40, 200, 400 and 1000μg/mL FPA/EPI NP for 24 hours were (92.3 ±5.2), (70.4 ±4.6), (50.0 ±4.0), (41.1 ±4.1) and (27.0 ±3.6) %, respectively.Compared with the NP control group, the Hela cells of the chlorpromazine , amiloride and folate groups showed a significantly lower rate of NP uptake (P<0.05), and so did the HepG2 cells pretreated with chlorpromazine or amilo-ride (P<0.05).At 72 hours, the half maximal inhibitory concentrations (IC50) of FPA/EPI NP against HepG2 and Hela cells were 168 and 105μg/mL, respectively . Conclusion Clathrin-mediated endocytosis and macropinocytosis are involved in the internaliza-tion of FPA/EPI NP in HepG2 cells, while clathrin-and FR-mediated endocytosis in that of Hela cells .FPA NP may serve as a new drug carrier for tumor-targeted therapy .

The professional identity and the influencing factors were surveyed among 110 resident physicians of general practice standardized training program in the First Affiliated Hospital of Xi'an Medical College with a self-designed questionnaire,and 100 valid questionnaires were received.The average score of professional identity was (66.10 ± 13.644),and the six dimensions ranked from high to low:professional behavior,professional efficacy,professional cognition,professional emotion,professional value and professional commitment.There were significant differences in the scores of professional identity among general practitioners with different monthly income(F=2.947,P=0.037).The survey indicates that the professional identity of the resident physicians of general practice standardized training program is generally low and the income is an important influencing factor.

Objective:To analyze the symptom characteristics of Coronavirus Disease 2019(COVID-19) and to improve its prevention by using big data.Methods:Using Baidu Index Platform (http://index.baidu.com) and the website of Chinese Center for Disease Control and Prevention as data resources, we obtained the search volume (SV) of keywords for symptoms associated with COVID-19 from January 1 to February 20 in each year from 2017 to 2020, in Hubei province and other top 10 impacted provinces in China and the epidemic data. Data of 2020 were compared with the previous three years. Data of Hubei province were compared with confirmed cases. The differences and characteristics of the SV of COVID-19-related symptoms, and the correlation between the SV of COVID-19 and new confirmed or suspected cases were analyzed and the hysteresis effects were discussed. R3.6.2 software was used to analyze the data.Results:Compared the data from January 1 to February 20, 2020, with the SV for the same period of previous three years, Hubei′s SV for cough, fever, diarrhea, chest tightness, dyspnea and other symptoms were significantly increased. The total SV of lower respiratory symptoms was significantly higher than that of upper respiratory symptoms ( P<0.001). The SV of COVID-19 in Hubei province was significantly correlated with new confirmed or suspected cases ( rconfirmed=0.723, rsuspected=0.863, all P<0.001). The results of the distributed lag model suggested that the patients who retrieved relevant symptoms on the internet may begin to see a doctor in 2-3 days later and be diagnosed in 3-4 days later. Conclusions:The total SV of lower respiratory symptoms is higher than that of upper respiratory symptoms, and the SV of diarrhea also increases significantly. It warns us to pay attention to not only the symptoms of lower respiratory tract, but also the gastrointestinal symptoms, especially diarrhea in patients with COVID-19. There is a relationship between internet retrieval behavior and the number of new confirmed or suspected cases. Big data have a certain role in the early warning of infectious diseases.

Objective:To explore the relationship of infertility-related stress and depression of infertility women, and the effect of coping style and resilience in it.Methods:A cross sectional study was conducted in 230 infertility women who treated with Assisted Reproductive Technology in Reproductive Medical Center of the First Affiliated Hospital of Soochow University using convenience sampling method from April 2020 to April 2021 with self-made general information questionnaire, Fertility Problem Inventory, Simplified Coping Style Questionnaire, 10-item Connor-Davidson Resilience Scale and Patients' Health Questionnaire Depression Scale-9 item. And correlation and effect analysis was conducted.Results:Two hundred and nineteen questionnaires were finally collected, the effective recovery rate was 95.2%(219/230). The score of Fertility Problem Inventory was (136.21 ± 27.38) points, the score of Simplified Coping Style Questionnaire was (34.26 ± 7.66) points, the score of 10-item Connor-Davidson Resilience Scale was (27.50 ± 6.78) points, the score of Patients' Health Questionnaire Depression Scale-9 item was (4.26 ± 3.83) points. Correlation analysis results showed that infertility-related stress of infertility women was positively correlated with negative coping ( r=0.20, P<0.01) and depression ( r=0.26, P<0.01), negative coping was positively correlated with depression ( r=0.23, P<0.01). Effect analysis results showed that negative coping had a partial mediating effect between infertility-related stress and depression, and the mediating effect size was 0.05, accounting for 15.63% of the total effects. Resilience moderated the second half path of the mediation relationship ( β=-0.137, t=-2.11, P<0.05). Conclusions:The infertility-related stress is a positive predictor of depression. Negative coping has a mediating effect between infertility-related stress and depression, and resilience moderates the effect of negative coping on depression.