Due to the restriction of the specific situation in China and the concrete conditions of universities,Problem-based learning teaching method failed to gain its popularity in medical education in China.In the era of information globalization,the web-based teaching method relying on the network and taking the PBL as the dominant has many advantages and there is nothing comparable to this.To establish a network of PBL platform in the area of medical education will provide medical education with a new chapter.

The growing trend of childhood obesity has attracted much attention globally.Overweight and obesity are not only popular in developed countries,but have spread to developing countries.China has entered an overall epidemic stage of childhood obesity.Studies have shown that obesity does not only impairs children's health,but also leads to health hazards in adult stage.Diabetes,coronary heart disease and other cardiovascular diseases may take place sooner or the incidence may become higher.The causes of obesity include genetic,early life events,physical activity patterns,diet and social psychological factors.This article reviews the current epi-demic status and the influencing factors of childhood obesity worldwide.

Dietary surveyis a method to evaluate whether dietary intake meets body requirements by recording food consumed during a certain period.Widely-used dietary survey methods include:24 h dietary recall,dietary record,food frequency questionnaire and dietary history questionnaire.Since each method has its own advantages and limitations,researchers need to choose appropriate methods according to research purposes,accuracy requirements,availability of resources,etc.Obese children who are the focus and the major difficulty in dietary survey,it is important to choose an appropriate survey method.This article reviews widely-used dietary survey methods and evaluates them in the study of obese children related dietary surveys.

Collagen fibrils and hydroxyapatite might recognize each other at the mesoscale by multiple cooperative interactions due to their intrinsically repetitive structured surfaces, and thus effectively directing the biomineralization, a biological process involving regulating the growth of bones, teeth and other organs. In this work, we developed a simple technique to prepare nanowire arrays of biological macromolecules by reversely using the biomineralization mechanism, with results similar to the hot wall epitaxy, a molecular beam deposition technique under vacuum. With this technique, we successfully cultured 5-10 μg/mL rat tail type I collagen monomer solutions into collagen nanowire arrays on the mica (001) lattice plane along one unique direction across the whole cleavage surface. The atomic force microscope experiments indicated that the nanowires in the arrays became more crowded with higher monomer concentration, but their width and height remained unchanged, about 60.0 nm and 1.5 nm, respectively. The collagen nanowire coating enhanced the hydrophilicity of the mica surface, reducing the contact angle from 25.8° to 9.5°. Based on the characterization results of electron back scattering diffraction and transmission electron microscope, the collagen nanowires were most likely to be oriented along the mica [110] direction, which validated the quasiepitaxial growth mechanism in more details.

Objective To investigate the demands and problems of the sharing and construc-tion of teaching resources in medical universities. Method A self-designed questionnaire named The questionnaire of the present situation and demand of teaching resources sharing platforms in medical universities in China was used to conducted in all the attainders during a national teaching resources meeting, and SPSS 17.0 was used to analyze the data. Results Among 125 valid questionnaires, 117 people (93.6%) think it's necessary to establish the resources sharing platform, what's more 108 people (86.4%) believe that education resources sharing platform is very helpful for teaching, and multimedia materials, online courses, course wares, teaching cases, website of subject resources and other educa-tion resources should be widely shared. Our investigation has involved 48 medical universities from all over the country, in which 33 medical universities have teaching resources sharing platform. However, 20 (60.6%) of the universities have still not updated the content on time. There are 10 main factors which influence the using of the education resource sharing platform, in which 105 (84%) of them have con-sidered the factor as backward concepts, 91 (72.8%) think that there exist problems in resource con-struction mechanism, 76 (60.8%) think to be the standardized and universal problems. Conclusion It is necessary to build the education resource sharing platform. In all, we should change the traditional education concept and consciousness, strengthen mechanism of management, and exploit high quality education resource to improve the sharing level of education resource in medical universities.

Objective To survey the biliary flora in patients with obstructive jaundice due to pancreatic head cancer,also the multiple factors which affect the positive findings of bile culture in these patients.Methods The information of 65 patients with obstruetive jaundice due to pancreatic head eancer,who admitted to surgery in Huashan Hospital from Oetober 2007 to October 2008 were reviewed retrospectively.The factors which may potentially affect the detection of bile pathogen in patients with malignant obstructive jaundice were studied with univarite analysis and muhivariate analysis,including age,history of biliary surgery,yellow stained time,serum alanihe aminotransferase level,serum bilirubin level,CA19-9 level,tumor size,site of obstruction,with or without clinical manifestations of biliary infection,and APACHE Ⅱ score.Results Twenty-five positive cultures happened in 65 bile samples (38.5％),including 21 strains of Gram-negative baeilli (72.4％),6 strains of Gram-positive bacteria (20.7％),and 2 strains of fungi (6.9％).Univariate analysis showed that the relevant factors which may affect the rate of positive bile culture in patients with malignant obstructive jaundice were age,history of biliary surgery,biliary obstruction site,biliary tract infection symptoms and APACHE Ⅱ score.Multivariate analysis showed that age,history of biliary surgery,biliary obstruction site and APACHE Ⅱ seore were independent risk factors.Conctusion Age,history of biliary surgery,biliary obstruction site and APACHE Ⅱ score were independent risk factors which led to positive findings of bile cultures in patients with obstructive jaundice due to pancreatic head cancer.

Objective To identify the types of pulmonary complications after pancreaticoduodenectomy,and to discuss the prevention and management of these complications.Methods Clinical data of 165 cases of pancreaticoduodenectomy in our hospital were retrospectively analyzed.Pulmonary complications were identified,therapeutic effects were observed.Results The incidence rate of pulmonary complications was 19.4％ ( 32/165),case-fatality rate was 6.25％ (2/32),two patients died from pneumonia,respiratory failure and ARDS.Complications mainly included pneumonia 13.9％ (23/165),pleural effusion 4.2％ (7/165),atelectasis 3.6％ (6/165),pneumothorax 1.8％ ( 3/165 ),respiratory failure 2.4％ (4/165) and ARDS 1.2％ (2/165).Conclusion Pulmonary complications after pancreaticoduodenectomy are not rare,especially for pulmonary infection and most are hospital acquired pneumonia.To understand rules and particularity of respiratory physiopathological changes after pancreaticoduodenectomy is very important for patients to safely pass over the perioperative period.

Objective To assess the value of multi-slice computed tomography angiography (MSCTA) in the preoperative detection of aberrant hepatic arteries in patients scheduled to undergo pancreaticoduodenectomy.Methods Patients with pancreatic and peri-ampullary tumors were preoperatively studied using contrast-enhanced abdominal CT angiography (CTA).The results on hepatic arterial anatomy were compared with those obtained from digital subtraction angiography (DSA) and on surgical findings.Results Eighty-one patients were included into this study.DSA was carried out in 29 patients to evaluate tumor resectability,and 66 patients received surgery.Anomalous hepatic arteries were detected in 17 (21％) patients on CTA.Thirteen (16.0％) patients had a single arterial variant,and 4 (4.9％) patients had two arterial variants.One patient each was seen in the Michels type Ⅳ,Ⅶ,and Ⅷ respectively,while 2 patients each were seen in the Michels type Ⅲ and Ⅴ respectively.Five patients were diagnosed as the Michels type Ⅵ,and four as the Michels type Ⅸ.One patient demonstrated a rare variant which was not included into the Michels classification.MSCTA had an accuracy of 100％,a sensitivity of 100％,and a specificity of 100％.Regarding the traceability scores of hepatic arterial segment,there were no statistically significant differences between MSCTA and DSA.Conclusions MSCTA is an effective imaging tool to assess arterial anatomical variation around the pancreatic head.It is non-invasive,and it provides valuable information on the peri-pancre atic vascular anatomy before pancreaticoduodenectomy.

Objective To investigate the clinical characteristics, diagnosis, treatment and prognosis of pancreatic gastrointestinal stromal tumor (GIST). Methods We reported a case and reviewed the medical literature on pancreatic malignant GIST. We searched the Pubmed and main domestic database. The clinical data of the reported cases were studied, and their predictive factors for postoperative recurrence and metastasis were analyzed. Results Between January 1980 and July 2010, 16 cases of pancreatic GIST were reported. There were 7 males and 9 females, with a median age pf 56.5 (31-72)years. The clinical symptoms were nonspecific. The main presentation was upper abdominal pain or discomfort. A preoperative diagnosis was suspected on radiological examination. The tumor mainly appeared as a well-defined solid-cystic mass. Irregular enhancement appeared in the circumferential and solid portion of the tumor on enhanced CT scan sequences. The pancreatic and biliary ducts were rarely dilated. Endoscopic ultrasound guided fine needle aspiration cytology (EUS-FNA) was helpful in preoperative diagnosis. Of the 15 surgical patients, 14 underwent complete resection, while the remaining received cyst-jejunostomy. A correct diagnosis was made on histopathology and immunohisto-chemistry. On a mean follow up of 21 months (range, 1-60) in 14 patients, all patients were alive.Recurrence or metastasis occurred in 4 patients with tumors of high malignant potential. On univariate analysis, the only significant predictor for adverse outcome was mitoses≥10/50 HPF. Conclusions Pancreatic GIST is a rare tumor of relatively low malignant potential. It has a better prognosis than ductal adenocarcinoma. It is important to arrive at a correct diagnosis and treat the tumor with radical resection. Aggressive surgical resection is potentially curative. Imatinib is recommended in the treatment of patients with tumors with high malignant potential.

Objective To confirm the main pathway of chemokine-chemokine receptor which mediates the accumulation of regulatory T cell ( Treg) in pancreatic cancer .Methods The concentrations of protein of FOXP3 and chemokines of CCL2, CCL3, CCL5, CCL17, CXCL8 in human and mouse pancreatic cancer and adjacent normal pancreatic tissue were measured by the method of enzyme-linked immunosorbent assay (ELISA).The receptor of chemokine CCL5 (CCR5) in human and mouse pancreatic cancer were determined by the immunofluorescent stain .Results The concentration of FOXP 3 protein in human pancreatic cancer and adjacent normal pancreatic tissue as (487.5 ±534.1) and (162.6 ±42.0) pg/mg, respectively, while they were (84.6 ±54.1) and (14.4 ±7.6) pg/mg, respectively in mouse.The concentration of FOXP3 protein were significantly higher in pancreatic cancer than those in adjacent normal pancreatic tissue .The concentration of CCL2 in human pancreatic cancer and adjacent normal pancreatic tissue as (76.9 ±37.5), (40.8 ±25.5) pg/mg, and the concentration of CCL3 as (38.0 ±22.6), (21.3 ±16.5) pg/mg, and the concentration of CCL5 were (390.2 ±158.5), (59.1 ±22.8) pg/mg, and the concentration of CCL17 as (7.2 ±2.0), (4.1 ±2.4)pg/mg, and the concentration of CXCL8 as (9.3 ±5.5), (6.3 ±5.2)pg/mg.The concentration of CCL2, CCL5, CCL17 in pancreatic cancer was significantly higher than those in adjacent normal pancreatic tissue (P<0.05).The concentration of CCL2 in mouse pancreatic cancer and adjacent normal pancreatic tissue as (77.9 ±30.5), (43.6 ±16.6) pg/mg, and the concentration of CCL3 was (27.4 ±18.2), (14.0 ±4.5)pg/mg, and the concentration of CCL5 was (302.2 ±55.8), (64.5 ±30.3) pg/mg; and the concentration of CCL17 was (4.4 ±1.4), (2.2 ±1.0)pg/mg;and the concentration of CXCL8 was (55.1 ± 55.1), ( 93.4 ±7.3 ) pg/mg.The concentration of CCL2, CCL5, CCL17 in pancreatic cancer were significantly higher than those in adjacent normal pancreatic tissue , and the difference between the two groups was statistically significant (P<0.05).The level of FOXP3 in pancreatic cancer was positively correlated with the concentration of chemokine CCL 5 both in human and mouse pancreatic cancer .Immunofluorescent staining indicated that the FOXP3 +cells also expressed CCR5.Conclusions The CCL5-CCR5 is the main chemokine-chemokine receptor pathway mediating the accumulation of Treg cells in pancreatic cancer .