By using a self-developed IF power and a ASTM contact material experimental system of small-capacity and variable frequency, the value of arcing characteristics and the welding force of the silver-based contact material are acquired under low voltage, resistive load and small current at 400 Hz and 50 Hz. By means of an electricity-ray analytical balance, SEM and EDAX, the weighing values of the contact materials and the changes of AgCdO, AgNi, AgC and AgW contact material surface profile and micro-area constituent are obtained and analyzed. The arc erosion causes of silver-based alloy contact materials at 400 Hz and 50 Hz are also discussed.

Objective To discuss the development and content of Chinese mental health assessment guideline.Methods Following literature review,initial assessment items were outlined by authors.A questionnaire survey concerniug assessment criteria was then conducted among the authorities in tbe field of psychology or psychiatry,A working group meeting was held to make the final decision.Results Ninety-five of 192 questionnaires were finally received,and those who knew much well about mental health accounted for 85.3％.Of 24 commonly used definition and criteria,5 assessment criteria and 15 essential items were agreed to use for mental health evaluation in Chinese populations.Conclusion The development of Chinese mental health assessment guideline is important to modify mental health evaluation and health care services in China.

AIM:To investigate the effect of cigarette smoking condensate on histone deacetylase 2 (HDAC2) and inflammatory mediators in mouse myoblast C 2C12 cells.METHODS:C2C12 cells were treated with cigarette smoke extract (CSE).HDAC2 siRNA was transfected into the cells using Lipofectamine TM 2000.The levels of interleukin-8 (IL-8) and tumor necrosis factor-α( TNF-α) in the culture supernatants were measured by ELISA , and the expression of HDAC2 at mRNA and protein levels was determined by real-time PCR and Western blotting .RESULTS:The expression of HDAC2 at mRNA and protein levels in CSE group was lower than that in control group (P<0.05).The supernatant levels of IL-8 and TNF-αin CSE group were significantly higher than those in control group ( P<0.05 ) .When the cells were transfected with HDAC2 siRNA followed by CSE stimulation , the expression of HDAC2 at mRNA and protein levels was de-creased , and the supernatant levels of IL-8 and TNF-αwere significantly increased as compared with CSE group and control group (P<0.05).CONCLUSION: Under the oxidative stress condition , C2C12 cells generate high levels of IL-8 and TNF-αby down-regulating the expression of HDAC2.

Objective:To investigate the synergistic effect and mechanism of the combined application of recombinant human bone morphogenetic protein-2(rhBMP-2) and basic fibroblast growth factor (bFGF).Methods:24KM male mice were randomly divided into6 groups with4 mice in each group, namely,GroupA(control group),GroupB(only treated with collagen),GroupC(treated with 2 ng bFGF+collagen),GroupD(treated with4 μg rhBMP-2+collagen),GroupE(treated with4 μg rhBMP-2+2 ng bFGF+collagen) andGroupF(treated with4 μg rhBMP-2+4 ng bFGF+collagen). The composites were implanted into the intermuscular septum of hind legs mice; whereas in control group, intermuscular septum of mice was separated and no implantation was performed. General observation, detection of concentration of calcium content, micro computed tomography (Micro-CT), three-dimensional reconstruction scan, measurement of bone mineral density(BMD), bone volume fraction(BVF) and trabecular thickness(Tb.Th), as well as histological observation withHE staining andALP andCD34 immumohistochemical staining were performed.Results:Ectopic osteogenesis was found inGroupsD,E andF mice.The difference in concentration of calcium contentswas statistically significant betweenGroupsD andE(P<0.05), but insignificant betweenGroupsE andF(P>0.05).Micro-CT and three-dimensional reconstruction revealed continuous newborn bone substance in external surface of ectopic bone formation, and the center of bone formation did not show obvious substantial filling by bone substance.The differences in BMD,BVF andTb.Th were statistically significant betweenGroupsD andE orF(P<0.01 or <0.05). HE staining showed that inGroupsD,E andF, newborn bone substance was mainly located at the edge of ectopic bone formation, and the bone formation inGroupsE andF was better than that in GroupD.ALP andCD34 immumohistochemical staining revealed the positive expression mainly at the edge of ectopic bone formation, and area of positiveexpression inGroupsE andF was larger than that inGroupsD.Conclusions:rhBMP-2 possesses the capacity to induce ectopic osteogenesis independently, but bFGF does not have this ability; the combined application of rhBMP-2 and bFGF can enhance the synergetic effect on inducing ectopic osteogenesis.

Objective There were few studies of prediction on type 2 diabetic patients with acute pulmonary thromboembo?lism.To evaluate the performance of the Padua score, revised Geneva score and Wells PE score in the prediction value of diagnosis of type 2 diabetes mellitus with acute pulmonary thromboembolism( APTE) . Methods 151cases with suspected APTE of type 2 diabe?tes were collected from January 2013 to December 2015 by a retrospective case analysis mode. Among 151 pations,80 cases had diag?nosed with pulmonary thromboembolism.The receiver operating characteristic (ROC) curve was used to evaluate the probability of type 2 diabetic patients with APTE predicted by the Padua, the revised Geneva and the Wells PE score. We calculated the Youden Index for the cut?off point. Results The area under curve( AUC) of the ROC curve in the Padua score, revised Geneva score and Wells PE score for APTE was 0.804±0.035、0.635±0.045 and 0.705±0.043. The area under the ROC curve of the Padua score was the highest and there was a significant difference compared with the revised Geneva( P<0.016 7) . The comparison of Padua score and Wells PE for the predication value was no statistically significant difference ( P>0.016 7) . The comparison of revised Geneva score and Wells PE for the predication value was no statistically significant difference ( P>0.016 7) . The cut?off of Padua score was 3 points and Youden Index was 0.51. The cut?off of Revised Geneva was 3 points and Youden In?dex was 0.24. The cut?off of Wells PE score was 1 points and Youden Index was 0.39. Conclusion Padua score, revised Geneva score and Wells PE score in predicting diabetes patients have some ex?tent clinical value terms, which Padua score has higher predictive value than the Revised Geneva.The predictive value of Padua score and Wells PE score was equivalent.However, the predictive value of Padua score is limited.

Objective To explore the application value of contrast-enhanced ultrasound(CEUS) in evaluating the effect of neoadjuvant chemotherapy(NAC) on breast cancer.Methods Image features of 80 breast cancer patients with neoadjuvant chemotherapy were observed and analyzed by CEUS.In the process,the changes of primary foci before and after neoadjuvant chemotherapy and the changes of qualitative and quantitative indexes of blood perfusion were evaluated.The correlation between qualitative change and pathological response was also studied.Results The change of focus size measured by CEUS was higher than that of conventional ultrasound before and after neoadjuvant chemotherapy(P ＜0.05).However,there was no significant difference between the two measurements before NAC(P ＞ 0.05).All the qualitative observation indexes of the ultrasound contrast after NAC revealed obviously benign conversion(P ＜0.05).Among them,the pathological response was closely related to the changes of the enhancement degree,the distribution of the contrast agent,the order of the contrast and the contrast mode.After NAC,the perfusion parameters of the lesions showed slowly crawl and slowly retreat,low enhancement and the diminished total amount of microcirculation perfusion.Conclusions Before and after neoadjuvant chemotherapy,the changes of the lesion size deteted by CEUS were more close to the pathological evaluation than those detected by conventional ultrasound.The benign outcome of qualitative and quantitative indexes of the CEUS was more obvious than the changes of the lesion size,which had practical value for guiding the neoadjuvant chemotherapy for breast cancer,especially the CEUS indexes related to pathological assessment.

Objective:To investigatethe maternal and infant adverse outcomes of group B streptococcus (GBS) colonization during the late pregnancy.Methods:A total of 567 pregnant women who underwent obstetrics and gynecology examination in Yuyao People′s Hospital from December 2018 to June 2019 were selected for the study. Internal vaginal secretions of all the pregnant women were extracted from the lower 1/3 of the vagina for bacterial culture, and GBS culture and screening were performed on pregnant women. According to the results of GBS screening, pregnant women were divided into GBS negative group (8 cases) and GBS positive group (559 cases). The general condition and pregnancy outcomes of pregnant women were compared between the two groups, and the correlation between pregnancy outcomes and streptococcus colonization was analyzed.Results:There were no statistically significant differences in age, gestational weeks, number of births, number of pregnancies, history of abortion, residence area and ethnicity between the two groups ( P>0.05). The incidence of premature rupture of membranes and fetal distress in GBS positive group were higher than those in GBS negative group:5/8 vs. 7.69%(43/559), 3/8 vs. 5.01%(28/559), and the differences were statistically significant ( P<0.05). Spearman single factor correlation analysis showed that GBS colonization in pregnant women were positively correlated with premature rupture of membranes and fetal distress ( r = 0.632, 0.573, P<0.05). Conclusions:GBS colonization in late pregnancy is closely related to pregnancy outcomes, and strengthening GBS screening has great significance to reduce adverse pregnancy outcomes.

BACKGROUND: Autologous bone, bone substitute materials and guided bone regeneration (GBR) technique can repair jaw defects, but the absorption speed of bone substitute materials and GBR membrane are faster than the formation speed of new bone, therefore, it affects the volume and shape of new bone.OBJECTIVE: To investigate the role of personalized prefabricated titanium template, autologous bone and nano-hydroxyapatite on restoration of maxillary defect in rabbit.METHODS: A total of 18 rabbits were randomly divided into two groups, and maxillary alveolar defect with 10 mm length and 5 mm high was created. The template was implanted in both two groups, and fastened with titanium screws. Autologous and nano-hydroxyapatite were placed into the defect in experimental group; neither autologous bone nor bone substitute materials were implanted into the defect in control group. New bone formation, X-ray findings, and histological changes with HE stain were carded out 4, 8 and 12 weeks postoperatively.RESULTS AND CONCLUSION: The quality of new bone in experimental group was batter than that in control group 4 weeks postoperatively, but the quality of new bone was almost the same 8 and 12 weeks postoperatively. By paired t-test, there was significant difference in new bone density between the experimental group and the control group 4 .weeks after operation (P<0.01), but there was no significant difference in new bone density between the experimental group and the control group 8 and 12 weeks after operation (P > 0.05). Autologous bone and nano-hydroxyapatite can restore the defect of maxillary alveola.Personalized prefabricated titanium template can play an important role of screen membrane and external scaffold in new bone formation, and remain shape of new bone.

Objective To investigate radioactivity levels in the main agriculture products around a uranium mine in Northern Guangxi.Methods The agriculture products and soil samples were collected and analyzed by using HPGe gamma ray spectrometer.Results The specific activity of 226Ra in radish (including leaf),radish leaves and radish,collected in one place,were 45.0,66.7 and 32.3 Bq/kg,respectively.Those of 226Ra and 23SU in the radish soil collected in the same place were 19 672 and 85 917 Bq/kg,respectively.The transfer coefficients of soil-to-radish and soil-to-leaves were 1.61 × 10-3 and 3.40 × 10-3,consistent with those reported in relevant literature.Radioactivity levels in agricultural products in another survey was in consistence with those in the national survey for food products.Radioactivity levels in soil elsewhere near the radish site was consistent with the results of the national soil radioactivive background survey.Conclusions The soil in this place has been contaminated by the nearby uranium mine.It is important to investigate this place further and take the necessary measures.