BACKGROUND:There are numerous studies about mechanical changes of recast cobalt-chromium ceramic al oys. However, little is reported on the mechanical properties of cobalt-chromium ceramic al oys containing once-used al oys after recasts.
OBJECTIVE:To study the effects of different proportion of once-used al oys to recasting cobalt-chromium al oys on their mechanical properties, including tensile strength, yield strength, elongation and hardness.
METHODS:Cobalt-chromium al oys cast samples were prepared and recast for three times (40%once-used al oys were added per time). The tensile strength, 0.2%yield strength, percentage of elongation, flexural strength and Vickers hardness of each specimen were measured. In addition, microscopic metal ographic observation was done.
RESULTS AND CONCLUSION:Being recast for three times, cobalt-chromiun al oys showed no significant differences on their tensile strength, 0.2%yield strength, percentage of elongation, flexural strength and Vickers hardness. GenerationⅠal oy samples had uniform size, smal diameter and smal carbide size distributing along the grain boundary, mainly exhibiting spherical and irregular wormlike forms. Generations Ⅱ and Ⅲ samples were uniform in shape, but crystal grains were coarsened a little. Carbide from Generation IV samples began to be coarsened, irregular wormlike carbides were increased in amount, and a few of non-metal ic inclusions could be found in grains. Cobalt-chromium al oys can be recast after addition of 40%once-used al oys for three times at least in air environment, without decrease of the mechanical properties.

Objective Through the research on relationship between achievement motive and personality traits,to provide the basis theory of personality attributes for selecting outstanding medical professional scientifically and effectively,and give some advice for improving medical education mode.Method The 310 medical staffs in sample hospital were treated as the research object in October 2015,who were randomly investigated with the big five personality questionnaire and achievement motivation scale,among of which,valid questionnaires were 290 copies leading to 93.5％ effective rate.SPSS 17.0 software was used to make t test,Chi-square analysis and correlation analysis for the data of the recover valid questionnaires.Result ①Personality traits of friendliness and rigor of the medical staffs of different gender exist statistically significant difference (t=-7.39,P=0.00;t=-8.28,P=0.00) and there were significant differences in the openness and rigor of medical staffs of different gender (P＜0.05).②The achievement motivation level of male medical staffs was higher than that of female (P=0.00),and there was no significant difference in achievement motivation among medical staffs.③The personality trait of neuroticism was negatively correlated with the pursuit of success and achievement motivation (correlation coefficient was-1.24),while the achievement motivation was positively related to extraversion and openness and the pursuit of success (the correlation coefficients were 1.51 and 1.53).Conclusion There is a significant correlation between personality traits and achievement motivation.The more extroverted personality medical staffs have,the more easy-going they are,and the more the pursuit of success oriented achievement motivation they have;and the higher the neurotic tendency individuals have,the more they incline to avoid failure of achievement motivation.

The safflower floret is a traditional Chinese medicine used to promote blood circulation and remove obstruction in the channels. The spines on its bracts are considered a handicap when manual harvest is involved. In this study, cDNA-SRAP was used to systematically investigate which genes are associated with the spines. Sixty pairs of possible primer combinations were used on two cDNA pools representing spininess and spinelessness. Six transcript-derived fragments were identified, of which two with low recombination were sequenced successfully and named as GPY-1 and GPY-2. By using the RACE method, the full-length cDNA of GPY-2 is cloned and named as CTL-spn. The full-length cDNA of CTL-spn was 1 679 bp long with a 1 524 bp ORF encoding a 508 aminoacid protein. The deduced amino acid sequence of the CTL-spn gene shared a high homology (97%) with other known ATP synthase CF1 alpha subunits. Semiquantitative RT-PCR analysis revealed that the mRNA of GPY-1 and GPY-2 accumulated in only spiny lines. Considering the important role of ATP synthase CF1 alpha subunit in plants, it may directly take part in the formation process of spininess and enhancing resistance reaction of spiny safflower. Also, our results provide the important insights for breeding spineless cultivars of safflower.

Objective·To study the change of circulating endothelial progenitor cells (cEPCs) in acute ischemic stroke (AIS) patients within one week after attack,and the correlation of cEPCs with the prognosis.Methods·Ninty-two patients with AIS (AIS group) and 20 patients with risk factors (Risk group) were recruited.The proportion of cEPCs (CD34TKDR+ cells) in peripheral blood mononuclear cells of AIS patients was measured by flow cytometry (FCM) on the first day of admission and the seventh day after attack.Functional recovery was assessed by modified Rankin Scale (mRS) on the 90th day after onset.The cEPCs percentages of AIS patients with different mRS were compared to analyze their correlation.Results·Compared with Risk group,cEPCs percentage of AIS group on the 1st day of admission was lower (P=0.016).In AIS group,compared with poor prognosis group (mRS＞2),eEPCs percentage of good prognosis group on the 7th day after onset (mRS ≤ 2) elevates (P=0.002).The result of multiple linear regression showed that cEPCs percentage on the 7th day after onset was positively correlated with mRS on the 90th day (t=4.608,P=0.011).Conclusion·The percentage of cEPCs in peripheral blood of AIS patients decreases significantly during the acute phase.The percentage on the 7th day after onset is correlated with prognosis of AIS patients.

Objective To study the expression of c -Met protein in gastrointestinal stromal tumor(GIST) and to evaluate its clinicopathological significance.Methods The immunohistochemical technique,EnVision method was used to evaluate the expression of c -Met in 105 cases of GISTs.Results c -Met protein positive rate in GISTs was 9.52%(10 /105),its expression rate was significantly higher in GISTs with >10 /50HPF mitotic activity(P <0.05).c -Met protein expression rate was higher in GISTs which >5cm,moderate or high -risk,or mass located outside the stomach,but the difference was not statistically significant(P >0.05 ).Conclusion c -Met protein expression may related with risk of GISTs.We think that c -Met is worthy of further study for its potential usage as a evaluation indicators of GISTs clinicobiological behavior.

were measured at the end of inspiratory.ResultsThe differences of following parameters were statistically significant between the healthy control group, mild PH group, moderate PH group and severe PH group: velocity time integral of ventricular systolic wave (SVTI), velocity time integral of ventricular diastolic wave (DVTI), AR, AR/S, ARVTI/SVTI, AR/(S+D), ARVTI/(SVTI+DVTI,F=2.940, 2.838, 3.373, 7.681, 3.478, 12.052, 4.806;P<0.05,<0.05,<0.05,<0.01,<0.05,<0.01,<0.01). Correlation analysis showed that ratio of AR/(S+D) was positively correlated with pulmonary artery mean pressure (r= 0.575,P<0.01). ConclusionsThe ratio of AR/(S+D) of MHV Doppler flow spectra was correlated with pulmonary artery mean pressure. The ratio increased along with the increasing of pulmonary pressure in CHD patient. The Doppler echocardiographic detection of MHV flow had a certain reference value for the diagnosis of PH. The ratio of AR/(S+D) could be a new non-invasive parameter for evaluating PH.

Objective · To survey the willingness to enroll in nursing homes among the elders in Shanghai and explore its predictors. Methods · A field survey was performed to collect data from 641 elders aged 60 years old and above in six community health centers in Shanghai. Sociodemographic variables, willingness to use nursing home, perceived barriers and perceived benefits were measured. Results · The questionnaire is with good structural validity and good intrinsic reliability. KMO index, P value of Bartlett's test of sphericity, and the range of Cronbach's α coefficients were 0.862, 0.000,and 0.739-0.824, respectively. Among the respondents, 46% were willing to enroll in a nursing home in this survey. Age had significant influence on their willingness (P=0.045). After adjusting for age, the multivariate Logistic regression analysis showed that shame (OR=0.76, 95% CI=0.62-0.94), adaptability (OR=0.61, 95% CI=0.50-0.74) and perceived benefits (OR=1.63, 95% CI=1.32-2.03) were related to willingness (P<0.05).Conclusion · Elders in Shanghai have a relatively high level of willingness to enroll in nursing homes, especially the elders aged from 60 to 69. Shame and adaptability of elders, and the services provided by nursing homes were the predictors of the elders' willingness.

OBJECTIVE To investigate the hepatotoxicity mechanisms of ethanol extract of Radix Polygoni Multiflori (RPM) and Radix Polygoni Multiflori Praeparata (RPMP) by high-content screen assay.METHODS HepG2 cells were treated with RPM (10,25,50,100,200 and 300 mg·L-1) and RPMP (10,50,100,300,600 and 1200 mg· L-1) for 3-24 h,respectively.The cell viability was detected by a CellTiter-GloTM luminescent cell viability assay kit.Cell count,reactive oxygen species (ROS),mitochondrial membrane potential (MMP),glutathione (GSH),superoxide dismutase 2 (SOD2),activating transcription factor 4 (ATF4),apoptosis,and cell cycles were investigated by high-content screen assay.Besides,SOD2 and ATF4 levels were confirmed by Western blotting.RESULTS RPM 300 mg· L-1 showed nearly 48 ％ reduction in cell viability compared with cell control (P＜0.01),while RPMP had no significant effect at the same concentration.Both RPM and RPMP decreased the level of MMP (P＜0.05) but incresed levels of GSH,ROS,SOD2 and ATF4 significantly (P＜0.05).Besides,RPM 200 mg· L-1 significantly increased the expression of SOD2 (P＜0.05) at 3 h by high-content screen assay,and the enhanced expression of ATF4 was shown at 6 h (P＜0.05).RPMP 300 mg· L-1 markedly increased the expression of ATF4 at 6 h (P＜0.05),while the expression of SOD2 significantly increased at 24 h (P＜0.05).CONCLUSION Both RPM and RPMP have some cytotoxicity,and the cytotoxicity of RPM is stronger than that of RPMP.The hepatotoxicity mechanisms of RPM and RPMP may be related to cell apoptosis caused by long-term oxidative stress and endoplasmic reticulum stress.

Aim To investigate the behavioral changes of the pain related neuromodulation and neurotransmission in peripheral and central nervous systems in rats with trigeminal neuralgia (TN)and provide a disease relevant animal model for mecha-nism study of TN.Methods The male SD rats were randomly divided into sham operation group and TN surgical group.The latter group was further divided into model group and gabapentin group (100 mg · kg-1 ). TN was induced by intravenous erythrosine B injection and laser irradiation.The pain behavior of rats was evaluated using mechanical pain threshold measured with Von Frey hairs.Fluorescence quantitative PCR technique was deployed to study the change of Tac1 mRNA expressions in trigeminal ganglia.Utilizing microdialysis technique followed by high performance liquid chromatography fluorescence detection (HPLC-FLD),the extracellular striatum fluid was collected and glutamate(Glu)concentration was determined.Results In the model group,the average mechanical pain threshold in facial ar-ea innervated by the trigeminal nerve remained below 4g after 7 days post surgery.The mechanical threshold of the model group (1.63 ±1.27)g was significantly lower (P<0.01)than the control group (24.17 ±4.49)g on day10 post surgery.In gen-eral,the mechanical withdraw threshold was decreased from the preoperative value of 26g to the postoperative value of (1.60 ± 1.74)g (P<0.01),and maintained stable at (0.71 ±1.24) g during the whole dynamic monitoring period from day7 to day60.The successful rate of this model was 63%.After sur-gery,Tac1 mRNA expression in trigeminal ganglia and extracel-lular Glu levels in striatum were significantly up-regulated (P<0.05 ) in the model group. Animals receiving Gabapentin showed significant improvement in pain symptoms,as well as re-ductions of Tac1 mRNA expression in trigeminal ganglia and ex-tracellular Glu concentration in striatum (P<0.05 ).Conclu-sions The above described photochemically induced TN rat model can partially mimic the clinical TN symptoms and its pathophysiology.Considering its overall high stability,it is very likely that this model could be used in preclinical mechanism study or drug screening of TN.

Objective To investigate the effects of fluoride on trabecular bone of the tibia and lumbar in BALB/c mice.Methods Totally 64 four-week-old BALB/c mice were randomly divided into 4 groups by weight,16 per group:control group (treated with distilled water) and 3 sodium fluoride (NaF) exposure groups (treated with NaF at 25,50 and 100 mg/L F-),respectively.At 12 weeks,mice were killed and blood,two hind limbs and lumbar were collected.Bone fluoride content and incidence rates of dental fluorosis were determined.Serum content of alkaline phosphatase (AKP) and acid phosphatase (ACP) were detected by micro enzyme labeled method.The ultrastructure of osteoblasts and osteoclasts in lumbar were observed via transmission electron microscope.The pathological changes of the trabecular bone of the tibia and the lumbar were observed under optical microscope,the percentage of trabecular area (％Tb.Ar) was measured with Image-Pro Plus (IPP) software.Results Bone fluoride contents of low,middle and high fluoride groups [(1 828.62 ± 102.93),(3 308.27 ± 185.63),(4 933.36 ± 301.16) mg/kg] were higher than that of the control group [(775.23 ± 92.56) mg/kg,all P ＜ 0.05].The incidences of dental fluorosis in the 4 groups were 0(0/16),47％(7/15),93％(14/15) and 100％(16/16),respectively;the difference was statistically significant (x2 =27.23,P ＜ 0.05).In middle and high fluoride groups,serum AKP [(18.30 ± 1.99),(24.50 ± 3.14) king unit/100 ml] and ACP [(11.97 ± 1.73),(11.31 ± 1.46) king unit/100 ml] were significantly higher than those of control [(14.63 ± 1.21),(9.07 ± 1.47) king unit/100 ml,respectively,all P ＜ 0.05].Under the electron microscope,osteoblast had developed organelles in each fluoride group,rough endoplasmic reticulum,Golgi body,and mitochondria were abundant,and nucleolus was obvious in the osteoblast.Osteoclast was rich in mitochondria,ruffled border clear and distributed phagocytic vacuoles in low fluoride group and middle fluoride group.Compared with the control group (17.03 ± 3.73),HE staining of tibia ％Tb.Ar in high fluoride group (28.79 ± 8.26) was significantly increased (P ＜ 0.05).The lumbar spine ％Tb.Ar in low,middle and high fluoride groups (15.87 ± 2.59,18.28 ± 0.89,21.99 ± 1.81) were higher than that of the control group (12.06 ± 1.76,all P ＜ 0.05].Conclusions BALB/c mice could be used as a model of skeletal fluorosis.Osteoblast and osteoclast are activated in BALB/c mice with skeletal fluorosis.Bone formation is more obvious than bone resorption and bone mass is increased.What is more,bone mass has increased more significantly in the lumbar spine of mice.