Questionnaire survey and semi-structured interview were done in December 2005 and April 2006 to explore the reasons why foreign and minority medical students failed in course examinations last year.It is found that many factors affect their studying such as proficiency in Chinese,original foundation,studying and living habits,familiarity to the regulations of educational affairs,time and effort spent for self-studying and the attitude in which the teachers treat them.And also the correspondent countermeasures are given according to the survey and interview.

With the rapid development of turfgrass industry in our country,more and more attentions are paid to the genetic breeding of turfgrass. Biotechnology has great application potential in varietals improvement of tall fescue,which is commonly grown as cool-season turf grass in the temperate region. The establishment of tall fescue regeneration and genetic transformation systems was summarized. Meanwhile,the historical and present situations of tall fescue breeding are introduced. The part of tall fescue regeneration was expounded from different explants and approaches. While,the part of genetic transformations was expounded from different means. At last,problems and prospects of genetic transformation of tall fescue are discussed.

OBJECTIVETo evaluate the biomechanical properties of tibial plateau depressed fracture fixed with a net-fixation of Kirschner wires.

METHODSTwenty homemade fracture models were fixed with eight 1.5 mm Kirschner wires in a net-fixation; 20 homemade fracture models were fixed with two 3.5 mm cortical screws. Plane-compressed and dot-compressed test were made on each 10 models of the two groups. The maximal force of anti-ompress and stiffness were measured and evaluated.

RESULTSIn plane-compressed test,mean maximal force of anti-compress and stiffness for screw fixation was (1,925.31 +/- 444.26) N and (2.28 +/- 0.53) N/mm2, respectively, for net-fixation was (1,609.62 +/- 277.72) N and (1.90 +/- 0.33) N/mm2, respectively. There was no statistical difference between the two fixation methods (P > 0.05). In dot-compressed test,mean maximal force of anti-compress and stiffness for screw fixation was (411.13 +/- 233.88) N and (2.66 +/- 1.52) N/mm2,respectively,for net-fixation was (1,105.58 +/- 290.66) N and (7.18 +/- 1.89) N/mm2,respectively,the net-fixation was better than that of the screw fixation (P< 0.01).

CONCLUSIONTreatment of tibial plateau depressed fracture with a net-fixation of Kirschner wires is a biological fixation and is a reliably method.

Objective Compare the complications between laparoscopic and abdominal cervical cancer surgery, and investigate the safety of laparoscopic cervical cancer surgery and complications classified by Clavien-Dindo classification, then analyze the risk factors. Method Clinical data of 215 cases of cervical cancer received surgery from March 2011 to October 2014 was collected, which include intraoperative, postoperative and postoperative fol﹣low-up data. All the cases were divided into two groups: LRH group (n= 116) and ARH group (n= 88), then ana﹣lyze and compare the difference of intraoperative, postoperative complications and postoperative follow-up data be﹣tween the two groups, assess the safety of the two groups, and statistically concluded related independent risk factors. Results The complications of 204 patients were classified into 4 grades. The criticality and morbidity of intraopera﹣tive and postoperative complications have no significant difference between the two groups (P> 0.05). Logistic re﹣gression analysis show that over criticality grade Ⅱ of LRH intraoperative complication related to operating time, over criticality grade Ⅱ of ARH intraoperative complication related to aged over 50 yr, over criticality grade Ⅱ of ARH intraoperative complication related to BMI> 25. Conclusions Through the analysis of laparoscopic operation and the criticality of complications, the safety of the two groups were no difference. The patients with high risk fac﹣tors should be evaluated comprehensively. And strictly grasp the contraindication and indication.

Objective To prepare Integrin αvβ3/CCR2 dual targeted microbubble,test physical-chemical properties,enhancement effect and targeting ability in vitro.Methods The dual targeted microbubbles (MBdual-target )with FITC labled iRGD and PE labled CCR2 were prapared,and non-target microbubbles as control (MBcontrol ) were prapered.Physical and chemical properties of two groups of microbubbles were tested,connectivity of peptides/antibodies and microbubbles were detected by fluorescence microscope and flow cytometry instrument.Enhancement effect and the stability of two groups of microbubbles was observed and compared in vitro.The affinity of MBdual-target and MBcontrol for bEnd.3 cells was investigated with light and fluorescent microscope.Results ①The particle size of MBdual-target was (0.93±0.23)μm,with no statistically significant difference compared with MBcontrol (P >0.05).②MBcontrol showed no fluorescent,while MBdual-target showed both clear green and red light,under fluorescent microscope.③There was no significant difference of gray scale of enhancement between MBdual-target and MBcontrol in vitro.④ It was showed that MBdual-target adhered to bEnd.3 cells in vitro experiment.Conclusions Integrinαvβ3/CCR2 dual targeted targeted microbubbles was successfully prepared and proved having good enhancement effect and targeting ability in vitro.

Information management system of nuclear medicine (IMSNM) is an important part of modem medical information system.It is used for the scientific management of clinical works,and classification and storage of patient data and examination data (words and images).With the help of IMSNM,standardization,automation and digitization of clinical operation protocols,the scientific and normalized management,the unification of image storage and viewing could be achieved.The IMSNM plays an important role in the health care,education and scientific research.This study mainly describes the design and application of IMSNM.

To meet the challenges of the current evaluation system for the residents , the department of internal medicine of Peking Union Medical College Hospital (PUMCH) developed a new on-line system.This new system, not only solved the problems of the current system , but also had several advantages as manpower saving , real-time update , back-to-back evaluation , convenience in comparison .This promising system is a possible solution to simi-lar problems in other institutions .

Objective To investigate the pharmacological effect and mechanism of mouse intermedin (IMD)for antagonizing cardiac hypertrophy by using isoproterenol (ISO)induced mouse cardiomegaly model.Methods The mouse cardiomegaly model was constructed by small dose of ISO subcutaneous injection.The mouse blood dynamic indexes and heart weight/body weight rati-o were investigated.Then the cardiomyocyte cross-sectional area,apoptosis and cardiac tissue fibrosis were evaluated by using the cardiac tissue section.ANP,BNP,mRNA expression levels of endogenous IMD and its receptors system in cardiac tissues were de-tected by using real time fluorescence PCR method.Results Compared with the ISO induced mouse cardomegaly model group,the intraperitoneal injection of IMD significantly decreased the heart weight/body weight ratio and cardiomyocyte cross-sectional area increased by ISO treatment,cardiomegaly marker ANP and BNP mRNA level,cardiomyocyte apoptosis and cardiomyocyte fibrosis, improved the cardiac function,left ventricular pressure,maximal and minimal rate of LV pressure increase and decrease during the isovolumetric contraction phase,stroke volume,cardiac output and ejection fraction,but significantly decreased the left ventricle end-diastolic pressure.In addition,the ISO treatment significantly induced the expressions of endogenous IMD and its receptors in heart tissues.Conclusion ISO induces the expressions of endogenous IMD and its receptors in cardiac tissues,and exogenous IMD sup-plementation therapy realizes the pharmacological protective effect for antagonizing cardiomegaly by ISO activated IMD receptor system.

Atomic absorption spectrometry was employed to determine the levels of 7 essential trace elements in the whole blood of 150 mainteinance hemodialysis (MHD) patients.And comparisons were made with the normal group of 200 participants in routine medical examination at the same time at our hospital.And among 7 indices,as compared with the control group,the blood levels of zinc,chromium,cobalt and manganese were significantly lower (P ＜ 0.05) while those of selenium and copper higher (P ＜ 0.05).MHD patients lacked essential trace elements to a varying extent.A clinician should pay attention to complementing essential trace elements to improve the patient's quality of life.

ObjectiveTo evaluate the security and effectiveness of minimal invasive fixation with 3D fluoro-images navigation in the management of acetabular fractures.MethodsFrom August 2008 to December 2010,20 patients with acetabular fractures were treated with percutaneous screw fixation under the guidance of 3D fluoro-images based on navigation system after closed reduction.There were 9 males and 11 females,aged 26-54 years old(mean,37.1±1.2 years).Fractures were caused by traffic accident in 15cases,and falling from height in 5 cases.According to AO classification,there were 2 cases of A1.1 type,3 cases of A2.2 type,4 cases of A2.3 type,2 cases of A3.2 type,2 cases of A3.3 type,2 cases of B1.1 type,2 cases of B2.2 type,1 case of B3.1 type,1 case of C2.1 type,1 case of C2.3 type.The interval from injury to hospitalization was 2-46 h (mean,8.6±0.2 h).After 3-14 days of skeletal traction through tibial tubercle,the operation was performed.ResultsTotally 46 screws were fixed.The average time for surgery was(22.6 ±1.2) min per screw.Forty-five screws were placed correctly with a successful rate of 97.8％,only one screw was reinserted for deviation.All the screws were checked by the 3D fluoro-images that they were not in the joint space after fixation.The result was same with CT scan.No incision problem and implant failure occurred.All 20 patients were followed up 12 to 28 months with an average of (22.8±1.7) months.At last follow-up,fracture union was achieved in all patients with satisfactory screw fixation.ConclusionThe minimal invasive fixation with 3D fluoro-images navigation makes the surgery for the nondisplaced acetabular fracture more precise and time-saving,minimize the surgery injury,and improves clinical results without an increasing rate of complications.