Objective To know the pollution status and the cytotoxicity of PM2.5 in Hangzhou,Zhejiang.Methods PM2.5 was collected in the center of Hangzhou city in spring and summer in 2005,the weighting method was used for PM 2.5 collection.WI-38 cell line was used as the target and the cells were treated with PM2.5 at different doses.The cytotoxicity of PM2.5 was tested by cloning efficiency.Results According to the Air Quality Standard for PM2.5 of U.S.EPA(issued in 1997),it was showed that the rates exceeding standard of PM2.5 concentration in spring and summer were 96.7% and 90.0%,respectively,but the rates were 33.3% and 20.0% compared with the standard newly issued in 2006.WI-38 cell survival rate was 100%,99.6%,96.2%,85.0%,73.8%,54.6% and 100%,97.0%,96.9%,88.0%,83.0%,64.7% respectively when treated with PM2.5 in spring and in summer of 0,25,50,100,200,500 ?g/ml.There was a significant difference except 25 ?g/ml and 50 ?g/ml in summer.Conclusion There is an obvious PM2.5 pollution in Hangzhou,which is heavier in spring than in summer,the cytotoxicity of PM2.5 in the polluted air may be higher.

Objective To discuss the application of DWI and DTI in diagnosis and evaluation of brain tumor. Methods Combining with literatures, the application of DWI and DTI in brain tumor diagnosis, differential diagnosis, tumors classi- fication, preoperative evaluation, operation plan establishment, follow-up role of treatment were reviewed and evaluated. Results The DWI and DTI were available to brain tumor diagnosis, differential diagnosis and tumor grade. The DTI could be clearly shown the influence of tumor with white matter quality, it was important in operation plan establishment. The combination of intra-operative MRI, functional MRI and DTI was valuable for brain tumor resection. In the meantime, the treatment response of tumor and the changes of treatment-induced white matter were accurately assessed by DTI. Conclu- sion With the MRI hardware and software technology development, the DWI and DTI imaging information can be provided important value in brain tumor pathological changes diagnosis, evaluation, therapeutic planning and post treatment assess- ment.

Objective To understand the influencing factors of the post competency of health technical personnel in township hospitals in a prov-ince,so as to provide scientific reference for improving health professionals'post competency. Methods Using stratified cluster random sam-pling,1242 health professionals from township health centers and village clinics of 14 cities were extracted and then surveyed with questionnaire. Results The average score of the respondents'post competency was 3.43,which meant they could afford most of the work. Multiple linear re-gression analysis showed that the main influencing factors of the professionals'post competency included gender,age,specialty,and training. The female,senior,nursing and health-care professionals with training exhibited a better post competency. Conclusion To realize the further develop-ment of professionals'post competency,medical students should not only be early clinical and more clinical,but also actively participate in the training and continue the education after entering the clinic. On the other hand ,the government should define the function orientation of the town-ship healthy centers and explore human resource management mode based on the post competency.

Objective To analyze the possible prognostic factors of thoracic-esophageal cancer patients with lymph node (LN) metastasis after esophagectomy plus three-field lymphadenectomy.Methods 590 esophageal cancer patients with LN metastasis after esophagectomy plus three-field lymphadenectomy were recruited from Jan.1993 to Mar.2007,and the prognostic factors and causes of postoperative failure were analyzed.Results Five-year survival in the whole sample was 29.6％.While the 5-year survival in different subgroups with 1-2,3-6 or ＞ 7 metastatic LNs were 41.2％,22.2％ and 7.0％ (x2 =62.158,P ＜0.0001),respectively.Univariate analysis showed that tumor site,disease length,T stage,number of metastatic LN and the seventh edition of AJCC staging system were prognostic factors.Multivariate analysis indicated that tumor site and number of metastatic LN were two independent prognostic factors.Conclusion Tumor site and number of metastatic LN were independent prognostic factors influencing the outcome of esophageal cancer.

Objective To investigate the prophylactic effect of thymosin α_1 on acute exacerbation of chronic obstructive pulmonary disease(AECOPD)in elderly patients.Methods One hundred and twenty COPD patients were randomized into two groups(n=60 for each).Patients in the treatment group received thymosin α_1 1.6 mg subcutaneously,2/week for 8 weeks;while patients in control group received normal saline instead.Serum CD3,CD4,CD8,IrA,IgG and IgM levers were measured,and the pulmonary function were examined before and 2.12 months after treatment.Results In treatment group the recurrence interval of AECOPD Was extended:the attack frequency and persistence time of AECOPD were significantly lower in cutuparison with those of the control group(P＜0.05).CD4 and CD4/CD8 levels were significanfly increased(P＜0.05)after treatment of thymosincd.Conclusion Thymosin α_1 Can protect acute exacerbation of chronic obstructive pulmonary disease in elderly patients.

Objective:To prepare a virus-like particle (VLP),containing Hepatitis B virus core antigen (HBcAg) and N-terminal peptides of the L2 protein of human papilloma virus (HPV),and investigate the immunogenicity of the VLP in mice and the protection against different strains of HPV .Methods:A fusion gene was synthesized to insert a DNA fragment ,coding for the N-terminal epitopes of the L2 protein of HPV16,into the HBcAg coding sequence;HBc-L2 fusion protein was highly expressed in E.coli using the pET9a and BL21(DE3) expression system;the purified fusion protein was used to immunize BALB/c mice and antibody titers against the L2 epitopes in mouse sera were determined by indirect ELISA;the levels of neutralizing antibodies against both HPV 16 and 18 were also analyzed.Results:HBc-L2 fusion protein was expressed in E.coli and purified,with the purity >80%,by ammonium sulfate pre-cipitation and CL-4B gel filtration;analysis of the purified fusion protein ,using size exclusion chromatography with multi-angle laser light scattering detection ( SEC-MALS) and electron microscope ,revealed that HBc-L2 was assembled into a stable VLP structure auto-matically following its expression;immunization of BALB/c mice with the purified VLPs resulted in high antibody titers in mouse sera against the L2 epitopes;furthermore,it was demonstrated that the sera from the immunized mice had neutralization activities against both HPV16 and HPV18.Conclusion:The immunogenicity of the L2 epitopes was highly enhanced by the construction of HBc-L2 fusion protein and the formation of the VLP structure;the fusion protein was also capable of inducing protections against different serotypes of HPV,therefore,it could be a potential HPV vaccine with a broad coverage and low production cost .

Background and purpose: Lymph node (LN) metastasis of esophageal cancer of neck rate higher, but there is little bulk reports. This article aimed to analyze the characteristics of cervical lymph node metastasis (CLN) in thoracic esophageal squamous cell carcinoma (TE-SCC) and the clinical role. Methods:A total number of 1 131 TE-SCC patients underwent radical esophagectomy plus three-ifeld lymph node dissection at Fujian Provincial Tumor Hospital between Jan. 1993 to Dec. 2003, during which, 367 patients had pathological metastasis of CLN. Results:The metastatic rate of CLN was 33.2%for the entire group, 43.7%, 33.0%and 16.0%for the upper, middle and lower TE-SCC respectively. Single factor analysis showed that the metastatic rate of CLN was relevant with the tumor site, pathological differentiated degree, lesion length showed in X-ray, pT stage and the number of CLN (P<0.05). But multivariate regression analysis showed that the metastatic rate of CLN was just relevant with the tumor site, pT stage and the number of CLN (P<0.05). Metastasis of cervical paraesophageal lymph nodes was the most common, and Background and purpose: Lymph node (LN) metastasis of esophageal cancer of neck rate higher, but there is little bulk reports. This article aimed to analyze the characteristics of cervical lymph node metastasis (CLN) in thoracic esophageal squamous cell carcinoma (TE-SCC) and the clinical role. Methods:A total number of 1 131 TE-SCC patients underwent radical esophagectomy plus three-ifeld lymph node dissection at Fujian Provincial Tumor Hospital between Jan. 1993 to Dec. 2003, during which, 367 patients had pathological metastasis of CLN. Results:The metastatic rate of CLN was 33.2%for the entire group, 43.7%, 33.0%and 16.0%for the upper, middle and lower TE-SCC respectively. Single factor analysis showed that the metastatic rate of CLN was relevant with the tumor site, pathological differentiated degree, lesion length showed in X-ray, pT stage and the number of CLN (P<0.05). But multivariate regression analysis showed that the metastatic rate of CLN was just relevant with the tumor site, pT stage and the number of CLN (P<0.05). Metastasis of cervical paraesophageal lymph nodes was the most common, and supraclavicular lymph node metastasis was next, and metastasis of cervical profound lymph nodes and retropharyngeal lymph nodes were rare. The ratio of the number of CLN occupied the sum of the segmental CLN were 57.7%, 32.0%and 10.0%for the upper, middle and lower TE-SCC respectively (P<0.05). Right CLN of each segmental TE-SCC was more than left CLN. Conclusion:Independent factors on CLN in TE-SCC are the tumor site, pT stage and the number of CLN. Metastasis of cervical paraesophageal lymph nodes is the most common, and supraclavicular lymph node metastasis is next, and metastasis of cervical profound lymph nodes and retropharyngeal lymph nodes are rare.

Objective To analyze the operative therapeutic effect of proximal femoral nail antirotation blade (PFNA),dynamic hip screw (DHS) and femoral proximal locking compression plate (LCP)internal fixation in treatment with femoral intertrochanteric fracture of the aged.Methods Seventy-three aged patients with femoral intertrochanteric fracture were divided into 3 groups according to different internal fixation method:PFNA group (30 cases) was treated with PFNA internal fixation,DHS group (22 cases) was treated with DHS internal Fxation,LCP group (21 cases) was treated with LCP internal fixation.The operative time,intraoperative bleeding volume,fracture healing time,bad limb load time and hip joint function score were compared among the 3 groups.Results The operative time in PFNA group,DHS group and LCP group was (73.9 ± 8.5),(82.3 ± 10.6),(79.5 ± 11.2) min,there was statistical difference between PFNA group and DHS group (P ＜ 0.05),but there was no statistical difference between PFNA group and LCP group (P＞ 0.05).The intraoperative bleeding volume in PFNA group was significantly lower than that in DHS group and LCP group [(160.2 ± 15.6) ml vs.(208.4 ± 20.2) and (216.6 ml ± 24.9) ml],there was statistical difference (P ＜0.05).The fracture healing time and bad limb load time in PFNA group were significantly shorter than those in DHS group and LCP group [(97.4 ± 5.8) d vs.(101.2 ± 4.2),(110.0 ±8.3) d and (78.0 ±5.4) d vs.(85.9 ±7.6),(90.8±6.0) d],furtbermore DHS group were significantly shorter than those in LCP group,there were statistical differences among the 3 groups (P ＜ 0.05).There were no statistical differences in excellent and good rate of hip joint function score among the 3 groups (P ＞ 0.05).Conclusions PFNA is the ideal therapeutic method for femoral intertrochanteric fracture of the aged.It has better curative effect compared to the DHS and LCP,and has less surgical trauma and can shorten the recovery time.

‘Student-centered’ teaching model is the needs of higher medical education.In the process of education,we carried out comprehensive and systematic reforms by satisfying students' needs and improving students' ability as the main line.These reforms included change of teaching methods (the basic theory combined with clinical knowledge),increase of innovative experiments and change of evaluation system.These results showed that students were interested in these reforms,the innovation abilities of students were improved and students could pay more attention to the process of learning.

Objective To evaluate the effect of simulated training on in-service physicians electrocardiogram(ecg) theory and operational learning effect.Methods Sixty resident doctors were randomly divided into experiment group (n=30) and control group(n=30).The experimental group adopted teaching + simulation training mode to implement the theory and operation of ECG in continuing while the control group were taught only by lectures.Training effect of both groups was assessed by electrocardiogram theory and operation examination before and after training respectively,and by questionnaires at the end of the training as well.Data of the examination and questionnaires were analyzed by t test or x2 test.P＜0.05 was considered statistically significant.Results After training,the score of theory examination was (90.87 ± 6.67) points in experiment group and was (85.83 ± 5.5) points in control group,with statistical difference between these two groups(t=3.201,P=0.003).Score of operation examination was(93.40 ± 4.31) points in experiment group and was(77.03 ± 7.96)points in control group,with significant differences(t=10.204,P=0.000).The satisfaction degree of enhancing learning interest,theoretical knowledge and operation skill,and strengthening the concept of humauistic care were significantly better in the experiment group than in the control group (x2=34.737,6.405,42.088,41.713,P=0.000,0.011,0.000,0.000).Conclusions Application of simulated training in the study of electrocardiogram is obviously superior in effect to the traditional teaching model.It can improve the theoretical knowledge and operation skill,which is helpful in elevating the in-service physicians' comprehensive capability.