Since the examination of doctor's qualifications came into effect, methods that are set by standard to judge whether one passes the examination or not were in dispute all the while. This article is going to introduce four kinds of methods (Angoff method、Modified Angoff method、Nedelsky method、Borderline group method) which are commonly used at home and abroad. Summarizing their advantages, disadvantages and the usage in the process of standards setting in various countries, we aim to provide reference for setting cutoff score of the examination of doctor's qualifications in China.

Mobile reading has greatly impacted the use of printed Chinese books in academic libraries.It is the most important task to introduce the users-needed books in order to improve their utilization.Acquisition of Chinese books should be arranged closely around the need of users by studying the reading features of users under mobile reading environment and establishing the open channels for book recommendation and feedback information in order to improve its quality .

Objective To understand the present status and explore the influencing factors of quality of life(QOL)among medical students,so as to provide a reference for the improvement of the QOL. Methods A total of 1 898 medical students sampled by stratified cluster sampling method were recruited and investigated by wHO-BREF scale. The influencing factors were assessed by t-test and one-way ANOVA. The data were analyzed by SPSS 19.0. Results Scores of the physical,psychological,social relationship,environmental domain of quality of life were 64.99±13.28,61.85± 13.79,61.58±14.53,and 54.91±13.91,respectively. The results indicated grade,monthly income of family,physical training,quality of sleep and history of trauma were the influencing factors of QOL among medical students,and the differences were all statistically significant(P<0.05). Con?clusion The score of environmental domain of QOL among medical students was the lowest. In order to improve the QOL of medical students, schools should take different measures to them according to different grades or monthly income.

Objective : o evaluate the association between Crohn's disease (CD) and frailty using a Mendelian randomization (MR) approach, so as to provide the evidence for prevention and control strategies. Methods: Genetic association data for CD were collected through the International Inflammatory Bowel Disease Genetics Consortium, with 20 883 samples and 12 276 506 single nucleotide polymorphism (SNP), and genetic association data for frailty were collected through a meta-analysis including 175 226 samples and 7 589 717 SNPs. A forward MR analysis was performed using the inverse-variance weighted (IVW) method with 37 CD-associated SNPs as instrumental variables, and frailty as the study outcome, and a reverse MR analysis was performed with 13 frailty-associated SNPs as instrumental variables and CD as the study outcome. The heterogeneity was assessed using the Cochran's Q test, and the horizontal pleiotropy was assessed using the MR-PRESSO global test and MR-Egger regression. In addition, the robustness of the results was verified with the leave-one-out. Results: Forward MR analysis results showed that patients with genetically predicted CD had an increased risk of frailty index relative to those without CD (β=0.018, 95%CI: 0.011-0.026, P<0.05). Cochran's Q test detected no heterogeneity (P>0.05), and neither the MR-PRESSO test nor the MR-Egger regression revealed horizontal pleiotropy of instrumental variables (both P>0.05). Leave-one-out analysis showed robustness of the MR analysis results. Reverse MR analysis showed no association between frailty index and the risk of CD (OR=0.740, 95%CI: 0.206-2.661, P>0.05). Conclusions Genetically predicted CD is associated with an increased risk of frailty. It is suggested that screening and prevention of frailty should be reinforced among CD patients.

Objective To evaluate traditional surgical treatment, intraluminal strategy and hybrid operation on revascularization of atherosclerosis obliterans (ASO) of the lower extremity. Methods Clinical data of 197 ASO cases receiving revascularization from January, 1998 to December, 2008 were retrospectively analyzed. Seventy-seven cases underwent surgical treatment, 82 cases received intraluminal therapy, and 38 cases were treated by hybrid operation. The indications, clinical effect, complication and perioperational mortality of these three strategies were evaluated. Results 71% patients (164 cases) were followed up from 2 to 112 months. Surgical and intraluminal method had no statistical difference on long-term patency of aortic-iliac and femoral-popliteal artery (57% vs. 51%;48% vs. 42%). Hybrid procedure led to higher patency on multi-level lesion and concurrent thrombosis. The complications after surgery was higher than intraluminal on aortic- iliac and femoral-popliteal artery (31% vs. 12%;31% vs. 11%), and higher than intraluminal and hybrid on multi-level lesion (36% vs. 12% vs. 15%). The perioperative mortality of surgical group was 1.5% and 2.0% on aortic-iliac and multilevel lesion and 0% on other site;and that of intraluminal and hybrid procedure was 0%. Conclusion For aortic-iliac and femoral-popliteal artery revascularization, surgery was preferred in cases of long occlusive lesion and intervention was preferred for cases with short non-occlusive lesion. Hybrid procedure was the best for multi-level and concurrent thrombosis.

Using mutation PCR, we cloned the target gene containing 421-480nt (141-160aa) and 598-639nt (200-213aa) of VP1 gene of foot and mouth disease virus (FMDV) into the deleted region (508-532aa) of Nsp2 gene of a highly pathogenic porcine reproductive and respiratory syndrome virus derived vaccine strain (HuN4-F112) that was used as vector. The recombinant cDNA was in vitro transcribed followed by transfection of BHK-21 cells for 36 h. Then, the supernatant of the cell culture was continuously seeded to monolayer of MARC-145 cells for recovery of the recombinant virus. CPE was obviously visible after a couple of passages in the seeded MARC-145, and the rescued virus (designated as rPRRSV-F112-O/VP1ep) was identified by Mlu I digestion, sequencing and immunofluorescence assay. Meanwhile, expression of inserted FMDV epitopes was also detected by indirect immunofluorescence assay with polyclonal antibodies against VP1 protein of FMDV. The analysis of biological characteristics shows that the titer of the rescued recombinant PRRSV (TCID50 = -log10(-6.75)/0.1 mL) was similar to its direct parental virus rHuN4-F112-delta508-532, but higher than rHuN4-F112.
Animals ; Antigens, Viral ; immunology ; Base Sequence ; Capsid Proteins ; immunology ; Cell Line ; Cysteine Endopeptidases ; genetics ; Epitopes ; genetics ; Foot-and-Mouth Disease ; immunology ; prevention & control ; Foot-and-Mouth Disease Virus ; genetics ; immunology ; Molecular Sequence Data ; Mutation ; Porcine respiratory and reproductive syndrome virus ; genetics ; immunology ; Recombination, Genetic ; Swine ; Transfection ; Vaccines, Attenuated ; genetics ; immunology ; Viral Envelope Proteins ; genetics ; immunology ; Viral Vaccines ; genetics ; immunology

Using lipase segregation agar containing trioleoylglycerol, we obtained 18 lipase positive clones by screening from a metagenome library of dairy rumen microflora containing 15,360 clones. The average insert size of lipase positive clones was about 60 kb. Lipase enzyme activity analysis by p-NPP method indicated that Lipase6, Lipase7 and Lipase8 had higher lipolytic activities to substrates of p-nitrophenyl palmitate (C16), p-nitrophenyl alaurate (C12) and p-nitrophenyl palmitate (C16) respectively. The optimum pH of Lipase 6, Lipase 7 and Lipase 8 were 7.5. The halflife period of Lipase 8 with the value of 15 min in 70 degrees C decreased with the increase of temperature. In conclusion, the lipases screened in this study had different substrates specificity and good thermo stability, which laid a basis for large-scale industrial application.
Animals ; Bacteria ; genetics ; Cattle ; Cloning, Molecular ; Female ; Gene Library ; Lipase ; genetics ; metabolism ; Metagenome ; genetics ; Rumen ; microbiology ; Substrate Specificity ; Temperature

Objective: To evaluate the clinical value of a rapid respiratory syncytial virus (RSV) antigen detection in point-of-care testing (POCT). Method: A total of 209 specimens, including 78 throat swabs (TS) and 131 nasopharyngeal aspirates (NPAs), were collected from inpatients who visited the Children′s Hospital Affiliated to the Capital Institute of Pediatrics and were diagnosed as acute respiratory infection from 5 January to 7 February, 2015. These specimens were tested for RSV by a rapid antigen detection kit which was compared with reverse transcription polymerase chain reaction (RT-PCR) and direct immunofluorescence assay (DFA) for RSV detection. Result: Compared with DFA for NPAs, the sensitivity and specificity of rapid antigen detection were 83.9% and 97.3%, respectively, with Kappa value of 0.86; Compared with RT-PCR, the sensitivity (NPAs, 74.2%; TS, 77.8%) and specificity (NPAs, 100.0%; TS, 92.0%) of rapid antigen detection were high, too, with Kappa value of 0.74 in NPAs and 0.62 in TS. However, the RSV positive rate of rapid antigen detection in TS (21.7%) from pediatric patients with acute lower respiratory tract infection was lower than that in NPAs (78.3%), as well as that of RT-PCR (7.3% in TS verse 78% in NPAs). The RSV rapid antigen detection kit can be finished in about 10 minutes. Conclusion With characteristics of high specificity, high sensitivity, being rapid, efficient and easy to operate in comparison with DFA and RT-PCR, RSV rapid antigen detection in this study is suitable for POCT. For pediatric patients with acute respiratory tract infection, NPA was better than TS for RSV detection.

Objective:To determine whether the blood urea nitrogen to serum albumin (B/A) ratio was a useful prognostic factor of mortality in the patients with acute non-variceal upper gastrointestinal bleeding (ANVUGIB).Methods:Totally 1 120 patients with acute upper gastrointestinal bleeding (VUGIB) admitted to the Emergency Department from January 2019 to December 2021 were prospectively and continuously collected and 449 eligible patients with acute non-varicose upper gastrointestinal tract were finally enrolled. The clinical data, laboratory tests and endoscopic results of the patients were recorded, and the data from the 30-day survival group and the non-survival group were compared and analyzed.Results:Significant differences were observed in age, mean arterial pressure, pulse rate, albumin levels, total protein levels, blood urea nitrogen levels, glucose, Glasgow-Blatchford score (GBS), Rockall, and AIMS65 scores between the survival and non-survival groups (all P <0.05). The B/A ratio in the non-survival group was significantly higher than that in the survival group [(24.9 ± 16.4) vs. (9.0 ± 8.6) mg/g, P<0.001]. Receiver operating characteristic (ROC) curve showed that the best cutoff value of B/A ratio for predicting 30-day death was 32.08 mg/g, with a sensitivity of 0.776 and specificity of 0.823. There was a significant difference in the 30-day Kaplan-Meier survival curve between patients with B/A ratio ≥32.08 mg/g and those with B/A ratio <32.08 mg/g (Log Rank 32.229, P<0.001). Multivariate logistic regression analysis revealed that the B/A ratio (≥32.08 mg/g) was associated with 30-day mortality ( OR=4.87, 95% CI: 1.94-6.85, P<0.001). Area under the ROC curve (AUC) for B/A ratio, GBS, Rockall and AIMS65 scores for predicting 30-day mortality were 0.855 (95% CI: 0.807-0.902), 0.849 (95% CI: 0.796-0.901), 0.657 (95% CI: 0.576-0.737), and 0.828 (95% CI: 0.774-0.883), respectively. Conclusions:The B/A ratio is a simple but potentially useful prognostic factor of mortality in the ANVUGIB patients.

Objective:To study the effect of different doses of 60Co γ-ray ionizing radiation on mitochondrial function in mouse hematopoietic stem and progenitor cells (HSPCs). Methods:C57BL/6 mice were divided into control group, 1 Gy irradiation group and 4.5 Gy irradiation group. The mitochondrial functions were detected at 12 h and 24 h after irradiation, including ROS level, membrane potential, mitochondrial structure, and mitochondrial stress. Bone marrow c-Kit + cells received a single 15 Gy irradiation in vitro, after 24 h, mitochondrial function was detected. Results:It was found that mice leukocytes ( t=12.41, 18.31, 16.48, 14.16, 19.08, 20.25, P<0.05), red blood cells ( t=4.81, 6.62, P<0.05) and platelets ( t=4.33, 6.68, P<0.05) were significantly reduced. The numbers of bone marrow colony formation unit ( t=16.27, 55.66, 17.06, 43.75, P<0.05), and HSPCs ( t=5.16, 11.55, P<0.05) were decreased dose-dependently post-irradiation. Under 1 Gy irradiation, the mitochondrial function and mitochondrial basal metabolic index of HSPCs ( t= 7.36, 3.68, 4.58, 3.15, 3.15, P<0.05) were enhanced at 24 h post-irradiation. Under 4.5 Gy irradiation, mitochondrial number, mitochondrial membrane potential ( t=12.29, 10.46, P<0.05), maximal respiration and spare respiratory capacity were decreased ( t=7.81, 5.78, 6.70, 5.83, P<0.05), ROS level was increased ( t=4.63, 4.12, P<0.05). The basal respiration and oxidative phosphorylated ATP production were reduced at 12 h after irradiation ( t=8.48, 3.80, P<0.05); and the proton leakage was increased ( t=6.57, P<0.05) and coupling efficiency was reduced ( t=11.43, P<0.05) at 24 h after irradiation. In cultured c-Kit + cells, the level of ROS ( t=11.30, P<0.05) and the maximum respiration and spare respiratory capacity were increased ( t=4.25, 3.44, P<0.05) while the mitochondrial membrane potential was decreased ( t=34.92, P<0.05) significantly. Conclusions:A method for systematically assessing mitochondrial function in HSPCs was established, and the effect of ionizing radiation on mitochondrial function of HSPCs was clarified, laying a foundation for further revealing the mechanism of ionizing radiation-induced mitochondrial damage in HSPCs.