BACKGROUND:The mechanical performance and cytocompatibility of polylactic acid-polyethylene glycol (PLA-PEG) scaffold is poor via long-term experiments; therefore, other materials are added to the scaffold in order to improve its biological activity and mechanical properties. OBJECTIVE:To investigate the preparation process of carbon fiber (CF)-PLA-PEG scaffold, and to test its performance. METHODS:Modified CF-PLA-PEG composite scaffolds were prepared using solution injection-particle leaching method. Ultra-structure, porosity, water-absorbing quality, degradation rate and mechanical properties of CF-PLA-PEG composite scaffolds and PLA-PEG scaffolds were compared. Rat osteoblasts were co-cultured with these two kinds of scaffoldsin vitro, and the cel adhesion rate was detected by precipitation method after 12 hours. Cel counting was detected using MTT method to determine the cel proliferation at culture days 1, 3, 5, 7, 9. RESULTS AND CONCLUSION:The surface structure of PLA-PEG distributed uniformly, and the aperture was (404.0±10.5) μm. The carbon fiber surface of modified CF-PLA-PEG composite scaffolds had a lot of longitudinal grooves, the surface structure also distributed uniformly, and the aperture was (433.0±3.0) μm. Difference in scaffold aperture was of significance between the two groups (P < 0.05). The porosity, water-absorbing quality, elasticity modulus, compressive strength, degradation rate, cel adhesion rate and cel growth rate of CF-PLA-PEG were better than those of PLA-PEG (P < 0.05). These results show that the CF-PLA-PEG scaffolds have good mechanical property and cel compatibility.

Objective To explore the application and effect of three-dimensional animation teaching software combined with case based learning ( CBL ) in inguinal hernia clinical teaching . Methods Totally 30 eight-year program students of Grade 2008 of Peking University People's Hos-pital were randomly divided into the teaching software combined with the CBL group(n=15) and tradi-tional teaching group(n=15). Three-dimensional animation teaching software was used to simulate the whole process of inguinal hernia anatomy and physiology, pathogenesis, clinical manifestations, diag-nosis and treatment in teaching software combined with CBL group. CBL teaching was conducted by setting problems through typical case and case discussion under the guidance of the teacher . The teacher-centered teaching, teaching rounds and watching operation were used in the traditional teaching group . Theory examination and physical examination were given at the end of the study and achieve-ment differences were compared between 2 groups. Questionnaire was used to investigate students' evaluation of the teaching method in teaching software combined with the CBL group and data were statistically described using t test. Results Theoretical exam score of the teaching software combined with the CBL group was (94.80±1.54), superior to the traditional teaching group(86.10±1.86), and the difference was statistically significant(t=8.242, P=0.000). Clinical skill test score of the teaching software combined with the CBL group was (91.10±1.01), superior to the traditional teaching group (85.90±2.17), and the difference was statistically significant(t=8.531, P=0.000). The survey result showed that more than 80.00% students thought that this teaching method could arouse students' learning enthusiasm, promote their mastery and application of knowledge, strengthen their self-study ability, cultivating their clinical thinking and improving their learning efficiency. Conclusion The teaching method of three dimensional animation teaching software combined with CBL , as a new teaching mode, helps to improve the quality of teaching.

A questionnaire survey was conducted in 114 medical students of 4th year in eight-year program before and after community clerkship of general practice.The survey showed that there were significant differences in the awareness of the function and features of community health service,the doctorpatient relationship and the difference with large hospitals before and after community clerkship (P ＜ 0.05).The willingness of students to work in the community health service was low (P ＞ 0.05).85.1％ students (97/114) thought that the community health service center had a harmonious doctor-patient relationship,65.0％ (74/114) thought that full communication between general practitioners and patients was an important factor to build a harmonious doctor-patient relationship,66.6％ (76/114) felt satisfied,and 72.8％ (83/114) gained a lot in the clerkship.The results indicate that the community clerkship of general practice is conducive for students to understand theory,knowledge of general practice.

Postgraduate administration is faced with new challenge in the affiliated clinical hospital because of the increasing quantity of postgraduates.The paper analyzed the characteristics of postgraduate administration and the status quo of information system construction in the affiliated clinical hospital and proposed the ideas of constructing information system for postgraduate administration from three aspects including system-frame,system-function and system-management.The purpose of the study was to provide reference for improving quality of postgraduate administration.

Improvement of the review of dissertation for doctoral degree is important for the training of qualified doctors.Current practice includes double-blind review and open review.This paper compares and analyses the outcome of the two kinds of reviews and found that double-blind review is more objective that the other(the mean of open review score is 96.39±2.069,the mean of double-blind review score is 85.18±6.635.P=0.001,P＜0.01).In the end some suggestions are proposed to improve the double-blind review system.

The paper analysed the double-blind review result of Ph.D candidates' dissertation at Peking University People's Hospital.Rigor deficiency and inadequate knowledge about the research subjects were identified as the main problems.In the end some suggestions were proposed from two aspects,namely,full-process management of Ph.D training and supervisor-team construction.