Assessment or evaluation of student performance in a problem-based learning (PBL) curriculum is difficult to plan or implement.Many medical schools which have switched to a PBL learning format usually use traditional evaluation methods based on factual recalls, which usually has a negative influence on the learning style of the students, thereby reducing the impact of PBL. The purpose of this review is to discuss the various evaluation methods with a particular focus on methods applicable to PBL, so that we can make intelligent use of these methods in our PBL curriculum. In combination with evaluation methods adopted at McMaster University, the article makes an elaboration about them.

Objective To detect the generation of multidrug -resistant organisms(MDROs)in our burn unit and analyze the antibiotic susceptibility.Methods The specimens were inoculated into different disks to isolate and cultivate bacteria.The antibiotic susceptibility of pathogens isolated was detected and judged by CLSI(clinical and laboratory standards institute)2012.The productive rate of MDROs were detected.Results The detection rate of MRSA and ESBLs were the most,87 (38.3%)and 73 (32.2%)respectively.MRSA was absolutely resistant to penicillin,the drug resistant rates to gentamicin,ciprofloxacin,levofloxacin,tetracycline,and rifampicin were above 70.0%,to erythromycin and clindamycin 52.9%,to moxifloxacin and SMZ -TMP 16.1% and 18.4% respectively, and absolutely sensitive to vancomycin,linezolid and tigecycline.The drug resistant rates of ESBLs to ceftriaxone, aztreonam and gentamicin were above 60.0%,to amoxicillin/clavulanic acid,ceftazidime and tobramycin were about 40.0%,to piperacillin -tazobactam,ertapenem,amikacin and cefoperazone /shubatan were below 20.0%,and absolutely sensitive to imipenem and meropenem.The drug resistant rates of CRE to the familiar antibiotics were above 45.0% except amikacin (18.2%),CR -AB to the common antibiotics were above 80.5% except levofloxacin (25.0%),and MDR/PDR -PA to the familiar antibiotics were above 50.0%.Conclusion The detection and drug resisrance rate of multidrug -resistant organisms in our burn unit was high.The clinic should pay more attention to use antibiotics reasonablely and may combine drugs to treat MDROs.It is necessary to use the antibiotic reasonably within different people to postpone the generation of MDROs.

BACKGROUND:Liver fibrosis is a kind of chronic and active disease that is caused by various causes and characterized by the excessive accumulation of extracelular matrix. At present, use of Chinese herbs for the treatment of hepatic fibrosis has obvious advantages. Salvia miltiorrhiza has been shown to be highly effective in the treatment of hepatic fibrosis. However, the underlying mechanism needs further investigation. OBJECTIVE:To investigate the effects of TanshinoneⅡA on the expression levels of transforming growth factor-β/Smads signaling pathway related factors transforming growth factor-β, bone morphogenetic protein 7, Smad6 and Smad7 in the liver tissue of rats with hepatic fibrosis. METHODS:SD rats were randomly divided into three groups (n = 10): normal control, model and TanshinoneⅡA-treated groups. Rats in the model and TanshinoneⅡA-treated groups were subtaneously injected with olive oil-diluted 10% CCl4 ( 5 mL/kg) twice a week, 8 weeks in total, to build rat models of hepatic fibrosis. Four weeks after hepatic fibgrosis induction, rats in the TanshinoneⅡA-treated group received subtaneous injection of TanshinoneⅡA til eight weeks. Rats in the normal control group were subcutaneously injected with olive oil. RESULTS AND CONCLUSION: Western blotting and reverse transcription-polymerase chain reaction (RT-PCR) detection showed that in the model group, the expression of transforming growth factor-β in the rat liver tissue was significantly increased (P < 0.01) and the expression of bone morphogenetic protein-7, Smad6 and Smad7 was significantly decreased (P < 0.01) compared with the normal control group. TanshinoneⅡA could obviously reverse the expression of those factors above-mentioned (P < 0.01). The results suggest that TanshinoneⅡA can be used for treatment of hepatic fibrosis by decreasing the expression of transforming growth factor-β and increasing the expression of bone morphogenetic protein-7, Smad6 and Smad7.

Objective To explore the risk factors of diabetic nephropathy.Methods According to the excretion rate of proteinuria,90 patients were divided into 3 groups:normal diabetic proteinuria group (DM),diabetic micro-proteinuria group (DN1),and clinical diabetic proteinuria group (DN2).We compared patients'ages,diabetic course,cholesterol,triglyceride,glycosylated hemoglobin,high density lipoprotein cholesterol (HDL),low density lipoprotein cholesterol (LDL),serum p-selectin,serum C-reactive protein,urinary monocyte chemotactic protein,and proteinuria excretion rate.Logistic regression analysis was used to analyze the relation between DN and various factors.Results Differences among these groups were statistically significant in type 2 diabetic course,HDL,LDL,p-selectin,C-reactive protein,glycosylated hemoglobin,and urinary monocyte chemotactic protein (P ＜ 0.05).Logistic regression analysis showed that diabetic course,LDL,C-reactive protein,p-selectin,and urinary monocyte chemotactic protein were independent risk factor (OR values were 2.238,1.062,6.723,1.166,and 1.046).Conclusions Occurrence and severity of DN had relationship with course of diabetes,microvascular lesions,and inflammatory reaction.Emphasis on monitoring and evaluation of the DN-related factors would contribute to the prevention and treatment of DN.

BACKGROUND:Hip prosthesis needs to meet the good structural compatibility with femoral bone marrow cavity and the biomechanical properties of the original bone tissue. However, the difference of individual anatomical characteristics and the stress concentration in the local area after replacement directly affect postoperative combination of femoral prosthesis stem, force flow transfer and femoral reconstruction, and finaly result in aseptic loosening of hip joint in some patients.
OBJECTIVE:To analyze the biomechanical characteristics of modified biotype self-locking hip prosthesis by the method of finite element analysis, and to provide the reference for the application of self-locking hip prosthesis in hip replacement.
METHODS:Experimental design contained traditional biotype hip joint prosthesis group and self-locking hip joint prosthesis group. In accordance with the finite element models of self-locking hip prosthesis, 28 kinds of screw fixation were established. Three-dimensional models were generated in the Minics system. After the optimization of prosthesis, prosthesis was designed. In the Solidworks software, the femur was re-positioned and set for contacting set in Ansys to analyze the stress distribution and displacement distribution of the femoral-prosthesis-screw by Ansys. We compared the peak of stress and displacement of the femur and prosthesis, and analyzed the biomechanical stability of prosthesis.
RESULTS AND CONCLUSION:(1) By using the Ansys finite element method, we analyzed the stress and displacement distribution of the femoral-prosthesis-screw. The minimum stress peak value of the femur was 15.698 MPa. The minimum stress peak value of prosthesis was 45.491 MPa. The minimum stress peak value of screw was 8.359 MPa. The minimum displacement peak value of femur was 1.125 3 mm. The minimum displacement peak value of prosthesis was 1.039 6 mm. The minimum displacement peak value of screw was 0.566 4 mm. (2) Compared with the traditional biotype hip joint prosthesis group, in 28 kinds of self-locking hip joint prostheses, the stress was minimum in the group E. The displacement was minimum in groups A-F. Regarding comprehensive stress and displacement, groups A-F were the best combination. The maximum stress of femoral-prosthesis-screw was 18.936, 59.494 and 12.382 MPa. The maximum displacement of femoral-prosthesis-screw was 1.125 3, 1.039 6 and 0.626 3 mm. (3) These findings indicated that the stress and displacement parameters of groups A-F was the best parameter combination in 28 kinds of self-locking hip joint prostheses, and it is the recommended index of researching and developing self-locking hip prosthesis.

Objective To summary and analysis the clinical experiences on the three hole method of VATS surgery in treatment of primary spontaneous pneumothorax.Methods The clinical data of 276 cases of primary spontaneous pneumothorax undergoing VATS surgery from July 2005 to July 2011 were analyzed retrospectively.Results The operating times were 25 to 76 minutes,averaging (41.7 ± 2.1) minutes ; all with traces of bleeding; transiting assisted small incision operation in 5 cases;postoperative thoracic closed drainage extubation time of 4-13 days,average (6.7 ± 0.2) days,mild postoperative air leakage in 27 cases,moderate in 9 cases without severe leakage,leakage,postoperative pulmonary atelectasis in 7 cases,pulmonary infection in 2 cases,reexpansion pulmonary edema in 1 cases,postoperative follow-up for 6-17 months,averaging(10.2 ± 1.7) months,recurrence occurred in 7 cases,1 case of operation again.Conclusion Three hole method of VATS technique has short operating time,less trauma,fewer complications,faster recovery,shorter hospitalization time and other advantages,and the recurrence rate is low,which is the ideal mode of operation for the treatment of primary spontaneous pneumothorax.

Objective To explore the diagnostic value of four tumor markers analyzed with Logistic regression and receiver operator characteristic (ROC) curve in patients with lung cancer.Methods The serum levels of carcinoembryonic antigen (CEA) 、carbohydrate antigen 125 (CA125),cytokeratin 19 fragment (CYFRA21-1) and neuron specific enolase (NSE) were determined by radioimmunoassay in 112 patients with lung cancer and 74 patients with benign pulmonary disease.Four tumor markers were analyzed by Logistic regression and ROC curve.Results The serum levels of CEA,CA125,CYFRA21-1 and NSE in lung cancer patients were [4.53(2.22-11.53)ng/ml,28.97 (11.39-62.10) U/ml,4.05(2.29-8.18)ng/ml,14.11 (11.35-24.12) ng/ml],respectively,which were significantly higher than those in health adults[2.08 (1.45-2.52) ng/ml,12.90 (9.80-19.44) U/ml,1.53 (1.21-2.17) ng/ml,11.38 (9.07-12.80) ng/ml] (all P ＜ 0.01).According to regression equation Y =1/[1 + EXP (4.902-0.394X1-0.627X2-0.165X3)],the area under the ROC curve (AUC),sensitivity,specificity,and accuracy of new variable Y were 0.915 ± 0.020,79.46％,93.24％,and 84.95％,respectively.Conclusions Application of logistic regression and ROC curve increases diagnostic accuracy in lung cancer.

Objective To investigate the efficacy of proton pump inhibitors (PPI) combined with flupethixol melitracen in the treatment of non-erosive gastroesophageal reflux disease (NERD) with anxiety and depression.Methods Fifty six NERD patients with anxiety and depression were evenly divided into the positive treatment group and positive control group.Thirty NERD patients without anxiety and depression were set as negative control group.Both flupethixol melitracen (20 mg per day after breakfast) and PPI esomeprazole magnesium (20 mg per day,20 minutes before breakfast) were administrated in positive treatment group.Only esomeprazole magnesium was given in positive control group and negative control group and the dosage was same as that of positive treatment group.The treatment course of three groups was eight weeks.Before and after the treatment,the symptoms of patients were scored according to gastroesophageal reflux disease questionnaire (GERDQ),Hamilton anxiety scale (HAMA),Hamilton depression scale (HAMD) and Pittsburgh sleep quality index (PSQI).Adverse effects were also observed.Variance analysis was performed for the comparison among three groups.Variance analysis or Post-hoc analysis were used for comparison between two groups.Results The differences of different score value before and after treatment of three groups were statistically significant in total score of GERD Q,score of type A,score of type C,score of HAMA,score of HAMD and PSQI (F=6.32,3.93,5.63,49.61,78.69 and 7.07,all P＜ 0.05).The differences of the score value before and after treatment of positive treatment group in total score of GERD Q,score of type A,score of type C,score of HAMA,score of HAMD and PSQI (4.24±2.05,3.16±1.46,1(0,3),9.32±3.21 and 8.88±2.92) were all higher than those of positive control group (2.38±2.22,1.68±1.33,0(0,2),3.72±2.95 and 3.84±1.97) and negative control group (2.32±2.18,2.48±1.34,0(0,1),2.36±1.25 and 2.36±0.79).And the differences were statistically significant (positive treatment group vs positive control group:Post-hoc analysis,P=0.002,0.022,0.003,0.002 and 0.002; positive treatment group vs negative control group:Post-hoc analysis,P=0.001,0.021,0.004,0.001 and 0.001).The difference of the score value before and after treatment of positive treatment group in PSQI (4 (2,6)) was higher than that of negative control group (2 (1,3),Post-hoc analysis,P=0.001).Two cases of positive treatment group had mild dizziness and the symptom relieved after three to four days.Conclusions For NERD patients with anxiety and depression,anti-depression drug flupenthixol melitracen can be used and the effect is superior to using PPI alone.

Objective:To explore therapeutic effect of esmolol hydrochloride combined amlodipine on patients with hyper-tension complicated aortic dissection (AD) and its influence on patient's blood pressure (BP) and heart rate (HR) .Meth-ods:A total of 110 patients with hypertension complicated AD were randomly and equally divided into amlodipine group and combined treatment group (received amlodipine and esmolol) .Results:Compared with before treatment , after treat-ment 0. 5 ,1. 5 and 7h ,there were significant reductions in systolic blood pressure (SBP) and diastolic blood pressure (DBP) in both groups ,P<0.01 ,on 7h after treatment ,SBP level of combined treatment group significantly reduced than that of amlodipine group [(101.5 ± 7.8) mmHg vs .(123.4 ± 10.2) mmHg ,P<0.01];on 0.5 ,1.5 and 7h after treatment ,HR and rate pressure product (RPP) of combined treatment group significantly reduced than those of amlodipine group , P<0. 01 all. Compared with amlodipine group after treatment , there were significant rise in standard-reaching rates of BP (56.36% vs .87.27% ) ,HR (38.18% vs .92.73% ) and BP+HR (25.45% vs .81.82% ) in combined treatment group , P<0.01 all. Conclusion:Esmolol combined amlodipine can control blood pressure and heart rate rapidly ,safely and effec-tively in patients with hypertension complicated aortic dissection .

Objective:To investigate the occurrence of carotid artery abnormalities in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients and the related risk factors affecting the occurrence of carotid artery abnormalities.Methods:A total of 169 regular follow-up outpatients with HIV/AIDS from April 2003 to December 2019 in Peking Union Medical College Hospital, whose carotid artery ultrasound examination were performed from July 2015 to December 2019 were included. The patients were divided into young (≤44 years old), middle-aged and elderly (≥45 years old) according to their ages, and the physical examination data of the included patients were collected.The statistical methods were logistic regression analysis and single sample t test. Results:Among the 169 HIV/AIDS patients, 40(23.7%) had abnormal carotid artery and 129(76.3%) had no abnormal carotid artery. Middle-aged and elderly people (odds ratio ( OR)=3.85, 95%confidence interval (95% CI) 1.54-9.65, P<0.01), hypertension ( OR=6.24, 95% CI 1.95-20.00, P<0.01), hyperlipidemia ( OR=2.44, 95% CI 1.00-5.93, P<0.05), and elevated human leucocyte antigen (HLA)-DR + CD8 + /CD8 + ( OR=1.03, 95% CI 1.01-1.06, P<0.05) were the risk factors for carotid artery abnormality. The common carotid artery inner medium film thickness (IMT) of patients in HIV/AIDS group Ⅰ (20 to 30 years old), group Ⅱ (31 to 40 years old), group Ⅲ (41 to 50 years old) were (0.061 0±0.001 2), (0.062 9±0.001 4) and (0.065 6±0.002 6) cm, respectively, which were thicker than the control groups ((0.051±0.003), (0.056±0.004) and (0.063±0.002) cm, respectively). The differences were all statistically significant ( t=5.119, 4.775 and 1.739, respectively, all P<0.05). The common carotid artery IMT of patients in HIV/AIDS group A (30 to 44 years old) and group B (45 to 59 years old) were (0.062 6±0.001 1) and (0.072 3±0.003 4) cm, respectively, which were thicker than the control groups ((0.052±0.011) and (0.064±0.015) cm, respectively), the differences were both statistically significant ( t=9.520 and 3.012, respectively, both P<0.01). Conclusion:Younger HIV-positive people have a higher probability of abnormal carotid arteries and may be at greater risk of cardiovascular disease than HIV-negative people of the same age, suggesting that HIV-positive people, especially young people, should be examined early with ultrasound of the neck arteries to detect abnormalities and intervene as soon as possible.