OBJECTIVEThe purpose of this study is to investigate the influence of cryogenic treatment and age-hardening heat treatment on the corrosion behavior of a dental casting Ag-Pd alloy.

METHODSA low gold content dental casting alloy composed of Ag-Pd-Cu-Au was prepared for this study. Corrosion test was performed according to ISO 10271:2001 dental metallie-corrosion test methods. Experimental specimens were casted according to a standard dental lost-wax casting procedure, treated with solution by heating the specimens to 900 degrees C, and immediately quenched in ice water. The specimens were then divided into four groups and subjected to heat treatment, cryogenic treatment, and heat treatment combined with cryogenic treatment. The specimens after the solution treatment were taken as control. The metallographic structures of the specimens were observed. The electrochemical parameters and the quantity of non-precious metallic ions released were evaluated via electrochemical and static immersion tests.

RESULTSMetallographic observation revealed that all the treatments resulted in a change in the microstructure of the alloy. The treatments were effective in improving the electrochemical parameters, such as an increase in Eocp and Ecorr and a decrease in Icorr (P < 0.05). The amount of non-noble metal ions released showed no difference compared with the control group (P > 0.05).

CONCLUSIONAfter different treatments, the antierosion properties of the alloy satisfied the ISO requirements. Age-hardening heat treatment and cryogenic treatment improved the corrosion resistance of the alloy.

Objective To investigate the expression and correlation of interleukin-6(IL-6),myeloid cell leukelia-1(MCL-1) protein and MCL-1mRNA in cervical cancer,cervical intraepithelial neoplasia(CIN) and normal cervix.Methods Immunohistochemistry was used to detect the expression of IL-6 and MCL-1 protein in 30 samples of cervical squamous cell carcinoma,10 samples of CIN and 10 samples of normal cervix,and RT-PCR was used to detect the expression of MCL-1mRNA.Results The protein levels of IL-6 and MCL-1 were significantly higher in cervical cancer tissues than in normal cervix and CIN tissues(P

Objective To study the expression of cyclooxygenase(COX-2) and ki-67 in chronic cervicitis,cervical intraepithelial neoplasia(CIN),squamous carcinoma of the cervix(SCC)and their relationship.Methods Tissue samples were harvested respectively from normal,inflammational,CIN and 30 SCC tissues.The expression of COX-2 mRNA was detected by RT-PCR method.COX-2 and ki-67 proteins were detected by inmmunohistochemical method.Results The overall expression of COX-2 mRNA and protein was higher in inflammation,CIN and SCC groups than that in normal cervix(P

Objective To evaluate the changes in the expression of DJ-1 protein during myocardial ischemia-reperfusion (I/R) in diabetic rats.Methods Fifty male Sprague-Dawley rats,weighing 220-280 g,were used in this study.Type 1 diabetes mellitus was induced by intraperitoneal streptozotocin 65 mg/kg and confirmed by fasting blood glucose ＞ 16.7 mmol/L.Forty animals with type 1 diabetes mellitus were randomly divided into 3 groups:diabetes group (group D,n =10),diabetic sham operation group (group DS,n =15) and diabetic I/R group (group DIR,n =15).Another 10 non-diabetic rats in which citrate buffer 6 ml/kg was injected intraperitoneally were served as control group (group C).Myocardial I/R was produced by occlusion of the anterior descending branch of left coronary artery for 30 min followed by 120 min reperfusion in group I/R.At 120 min of reperfusion,5 rats were sacrificed and myocardial specimens were c(on)tained for determination of infarct size in groups DS and DIR,and 10 rats were sacrificed and myocardial specimens were obtained for microscopic examination and for determination of cell apoptosis,malondialdehyde (MDA) content,superoxide dismutase (SOD) activity and expression of DJ-1 and phosphatase and tensin homologue (PTEN) protein.Apoptotic index (AI) was calculated.Linear correlation between the expression of DJ-1 protein and MDA content,SOD activity,AI and expression of PTEN protein was analyzed.Results Compared with group DS,the myocardial infract size was significantly increased in group DIR (P ＜ 0.05).Compared with group C,MDA content and AI were significantly increased,SOD activity was decreased,the expression of DJ-1 was down-regulated,and the expression of PTEN protein was up-regulated in groups D,DS and DIR (P ＜ 0.05).Compared with groups D and DS,MDA content and AI were significantly increased,SOD activity was decreased,the expression of DJ-1 was down-regulated,and the expression of PTEN protein was up-regulated in group DIR (P ＜ 0.05).There was no significant difference in the parameters mentioned above between groups D and DS (P ＞ 0.05).There was linear correlation between the expression of DJ-1 protein and MDA content,SOD activity,AI and expression of PTEN protein and the correlation coefficients (r) were-0.734,0.593,-0.818,and-0.812 in turn.Conclusion Down-regulation of DJ-1 protein expression is involved in myocardial I/R injury in diabetic rats via decreasing anti-oxidative stress responses and upregulating PTEN protein expression.

Objective To analyze the related factors of influencing deep vein indwelling catheter dysfunction in hemodialysis patients.Methods A total of 37 cases with deep vein indwelling catheter in hemodialysis patients were selected.They were divided into patent group and blocked group according to the appearance of catheter dysfunction (hemodialysis blood flow less than three times 180 ml/min,adjustment of body position,inversion of tube connection during hemodialysis,requirement of thrombolytic therapy and so on) in 5 months.The common data and biochemical indicator were compared between two groups.Results Patent group had 28 cases,and blocked group had 9 cases.There was no significant difference in age,diabetes mellitus ratio,platelet,low density lipoprotein cholesterol and albumin between two groups (P ＞0.05).Hemoglobin in patent group was lower than that in blocked group [(90.1 ± 13.8) g/L vs.(108.3 ± 11.6) g/L],and there was significant difference(P＜ 0.05).Conclusion Hemoglobin is the correlated factor that effects deep vein indwelling catheter dysfunction after hemodialysis.

Objective To evaluate the prognostic value of lateral lymphadenectomy for advanced lower rectal cancer. Methods A total of 96 consecutive patients who underwent total mesorectal excision and lateral lymphadenectomy for advanced lower rectal cancer were retrospectively evaluated by using therapeutic index. A product of the frequency of lymph node metastasis and the cancer-related 5-year survival rate. Results The incidences of lymph node metastasis in mesorectal area, superior rectal artery area, inferior mesenteric artery area and lateral area was 21%,13%.10%and 15%respectively.The 5-year survival rate of patients with metastasis to the mesorectal area, superior rectal artery area, inferior mesenteric artery area and lateral area was 35%,25%,20%and 36%respectively.The therapeutic indexes for total mesorectal excision and lateral lymphadenectomy were 7.4 and 5.4,which were much higher than that of lymphadenectomy of the superior rectal artery area(3.3)and inferior mesenteric artery area(2.0).Local recurrence occurred in 19%(18 out of 96 cases)patients with advanced lower rectal cancer. Local recurrence rate of patients with positive lateral lymph node metastasis was 64%(9 of 14 cases),whereas it was 11%(9 of 82 cases)in those without lateral lymph node metastasis. The difference between these two groups was statistically significant(x2=22.308,P=0.000).Kaplan-Meier survival analysis showed significant improvements in median survival(80.9±2.1)m,95%CI:76.7～85.1 m vs(38±6.7)m,(95%CI:24.8～51.2 m)for patients with negative lateral lymph node metastasis over patients with lateral lymph node metastasis(log-rank,P=0.000). Conclusion The current results indicate that lateral pelvic lymphadenectomy could significantly reduce loeal recurrence and effectively improve the survival of patients with advanced lower rectal cancer. Except for total mesorectal excision, lateral pelvic lymphadenectomy should be followed in the surgery of pailents with advanced low rectal cancer.

Objective To explore the relationship between SHP1 and CD99 expression in Hodgkin lymphoma (HL) .Methods RT‐PCR and Western blot to detect the expression of CD99 and SHP1 mRNA and protein expression in IM9、KM3、L428、L428‐CD99 cells ;fluorescence confocal to observe the expression and co‐localization of CD99 and SHP1 ;transiently interference CD99 in IM9 cells and then detect the expressing of SHP1 mRNA and protein levels .Results SHP1 mRNA was low expressed in L428、KM3 and high expressed in IM9;gene and protein expression were consistent trend;in L428‐CD99 cell SHP1 mRNA expression and protein levels were higher than L428 cell;CD99 expressed in membrane and SHP1 expressed in cell plasma;transient interference CD99 ,SHP1 decreased in mRNA expression and protein levels .Conclusion In HL cells ,SHP1 expression related to the missing expression of CD99 ,and its mechanism remains to be studied .

Objective To develop a scale to measure three representative real relationships of undergraduates (parent-child relationship,collegemate relationship and teacher-student relationship) and test its validity and reliability(multi-interpersonal dynamics questionnaire for undergraduates,MIDQ-U).Methods A total of 1 310 students were conveniently sampled as respondents to analyze validity and reliability indexes.Result Three relationships share four factors for interpersonal dynamic characteristics:closeness,indifference,independence and submissiveness.The revised MIDQ-U composed of 26 items to separately measure characteristics of three relationships both separately and together.The factor loading of items in parent-child relationship scale were 0.41-0.73 and 50.71％ of the variances could be explained,while eollegemate relationship 0.41-0.72 and 51.81％ explained,teacher-student relationship 0.42-0.76 and 49.58％ explained.The model in 4 factors(x2/df =2.59,CFI =0.85) fitted the data with well construct validity.The Cronbach α coefficients were 0.847 in parent-child relationship scale,0.865 in collegemate relationship scale and 0.836 in teacher-student relationship scale.The test-retest reliabilities were 0.867,0.786 and 0.746.Conclusions The MIDQ-U has satisfactory validity aud reliability.It can be used to measure one of the three relationships separately,and also as an evaluation tool to compare and correlate multiple interpersonal dynamics.