合金元素对Pt基合金热弹性性能的影响

采用基于第一性原理计算的准静态近似方法,研究33种合金元素对Pt基合金热弹性性能的影响。研究表明:当稀土元素(Y、La、Ce或Th)固溶进入Pt基体后,由于稀土元素和Pt之间的平均键长较长,Pt基合金Pt_(31)X的弹性常数和弹性模量变小;与纯Pt相比,合金元素Ta、Nb、V、W或Mo固溶进入Pt基体后会产生强烈的电子局域化并使平均键长缩短,从而提高Pt基合金的杨氏模量;同时,由于Pt_(31)X(X=Ta,Nb,V,W和Mo)的平均键长随温度的升高缓慢增加,因此,其模量温度系数较小,其中,Pt_(31)W的模量温度系数最小(-15.82×10^(-5)K^(-1))。因此,W、Ta、Mo、Nb或V是潜在的具有增强Pt弹性稳定性的合金元素。

普鲁卡因对结肠癌细胞中孕酮及脂联素受体3甲基化的影响

目的研究孕酮及脂联素受体3(PAQR3)在结肠癌细胞中的表达水平及甲基化状态,检测普鲁卡因逆转PAQR3甲基化的作用。方法通过RT-PCR检测PAQR3在结肠癌细胞株(SW620、COLO205及SW480)中的表达水平;甲基化特异性聚合酶链反应检测PAQR3在结直肠癌细胞中的甲基化状态及药物处理后的甲基化状态;Western blotting检测不同浓度普鲁卡因处理SW480细胞中PAQR3蛋白的表达。结果PAQR3在SW620结肠癌细胞中的表达量高于COLO205和SW480(P<0.05)。3种结肠癌细胞株可见PAQR3基因甲基化特异性扩增产物条带,且甲基化百分比比较,差异有统计学意义(P<0.05)。SW620细胞较SW480和COLO205细胞中PAQR3甲基化百分比高(P<0.05);普鲁卡因处理后3种结肠癌细胞株可见甲基化特异性扩增产物条带和非甲基化特异性扩增条带,且3种细胞中PAQR3甲基化百分比降低(P<0.05)。对照组与实验组PAQR3蛋白相对表达量比较,差异有统计学意义(P<0.05)。与对照组比较,实验组PAQR3蛋白相对表达量升高(P<0.05)。结论PAQR3在结直肠癌中低表达,可能与其发生启动子甲基化有关。普鲁卡因可部分逆转结直肠癌细胞中PAQR3甲基化状态,上调PAQR3蛋白表达量。

Survival and prognostic factors in hepatitis B virus-related acute-on-chronic liver failure

AIM:To investigate the survival rates and prognostic factors in patients with hepatitis B virus-related acuteon-chronic liver failure(HBV-ACLF).METHODS:Clinical data in hospitalized patients with HBV-ACLF admitted from 2006 to 2009 were retrospectively analyzed.Their general conditions and survival were analyzed by survival analysis and Cox regression analysis.RESULTS:A total of 190 patients were included in this study.The overall 1-year survival rate was 57.6%.Patients not treated with antiviral drugs had a significantly higher mortality[relative risk(RR)=0.609,P=0.014].The highest risk of death in patients with ACLF was associated with hepatorenal syndrome(HRS)(RR=2.084,P=0.026),while other significant factors were electrolyte disturbances(RR=2.062,P=0.010),and hepatic encephalopathy(HE)(RR=1.879,P<0.001).CONCLUSION:Antiviral therapy has a strong effect on the prognosis of the patients with HBV-ACLF by improving their 1-year survival rate.HRS,electrolyte disturbances,and HE also affect patient survival.

Preoperative differential diagnosis between intrahepatic biliary cystadenoma and cystadenocarcinoma:A single-center experience

AIM: To investigate preoperative differential diagnoses made between intrahepatic biliary cystadenoma and intrahepatic biliary cystadenocarcinoma. METHODS: A retrospective analysis of patient data was performed, which included 21 cases of intrahepatic biliary cystadenoma and 25 cases of intrahepatic biliary cystadenocarcinoma diagnosed between April 2003 and April 2013 at the General Hospital of PLA. Potential patients were excluded whose diagnoses were not confirmed pathologically. Basic information (including patient age and gender), clinical manifestation, duration of symptoms, serum assay results (including tumor markers and the results of liver function tests), radiological features and pathological results were collected. All patients were followed up. RESULTS: Preoperative levels of cancer antigen 125 (12.51 +/- 9.31 vs 23.20 +/- 21.86, P < 0.05) and carbohydrate antigen 19-9 (22.56 +/- 26.30 vs 72.55 +/- 115.99, P < 0.05) were higher in the cystadenocarcinoma subgroup than in the cystadenoma subgroup. There were no statistically significant differences in age or gender between the two groups, or in pre- or post-operative levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin (TBIL), and direct bilirubin (DBIL) between the two groups. However, eight of the 21 patients with cystadenoma and six of the 25 patients with cystadenocarcinoma had elevated levels of TBIL and DBIL. There were three cases in the cystadenoma subgroup and six cases in the cystadenocarcinoma subgroup with postoperative complications. CONCLUSION: Preoperative differential diagnosis relies on the integration of information, including clinical symptoms, laboratory findings and imaging results. (C) 2014 Baishideng Publishing Group Inc. All rights reserved.

Elaborating strengthen mechanism of Pt-Ir solid solution superalloy at finite temperature

Pt-Ir alloy is potential superalloys used above 1300℃because of their high strength and creep resistance.However,the ductility of Pt-Ir alloy has rapidly deteriorated with the increase of Ir,resulting in poor machinability.This work quantitatively evaluated the solid solution strengthening(SSS)and grain refinement strengthening(GRS)of Pt-Ir alloy using first-principles calculations combined with experimental characterization.Here,the stretching force constants in the second nearest neighbor region(SFC^(2nd))of pure Ir(193.7 eV·nm^(-2))are 3.40 times that of pure Pt(57.0 eV·nm^(-2)),i.e.,the interatomic interaction is greatly enhanced with the increase of Ir content,which leads to the decrease of ductility,and modulus misfit plays a dominant role in SSS.Then,the physical mechanisms responsible for the hardness(H_(V))of Pt-Ir alloy,using the power-law-scaled function of electron work function coupled SSS and GRS,are attributed to the electron redistribution caused by different Ir content.Furthermore,a thorough assessment of the thermodynamic characteristics of Pt-Ir binary alloy was conducted,culminating in development of a mapping model that effectively relates enmposition,temperature and strength.The results revealed that the compressive strength incrcases with the Ir content,and the highest strength was observed in Pt_(0.25)Ir_(0.75).This study provides valuable insights into the Pt-Ir alloy system.

Hepatic Resection Versus Stereotactic Body Radiation Therapy Plus Transhepatic Arterial Chemoembolization for Large Hepatocellular Carcinoma:A Propensity Score Analysis

Background and Aims:There are no comparative studies on the efficacy of hepatic resection(HR)and CyberKnife stereotactic body radiation therapy(CK-SBRT)plus transhepatic arterial chemotherapy embolization(TACE)in the treatment of large hepatocellular carcinoma(HCC).Therefore,this study aimed to compare the efficacy of HR and CKSBRT+TACE in large HCC.Methods:A total of one hundred and sixteen patients were selected from November 2011 to December 2016.Among them,50 were allocated to the CKSBRT+TACE group and 66 were allocated to the HR group.The Kaplan-Meier method was applied to calculate overall survival(OS)and progression-free survival(PFS)rates.Propensity score matching was performed to control for baseline differences between the groups.Results:Thirtysix paired patients were selected from the CK-SBRT+TACE and HR groups.After propensity score matching,the 1-,2-and 3-year OS rates were 83.3%,77.8%and 66.7%in the HR group and 80.6%,72.2%and 52.8%in the CKSBRT+TACE group,respectively.The 1-,2-and 3-year PFS rates were 71.6%,57.3%and 42.3%in the HR group and 66.1%,45.8%and 39.3%in the CK-SBRT+TACE group,respectively(OS:p=0.143;PFS:p=0.445).Both a high platelet count and low alpha-fetoprotein value were revealed as influencing factors in improving OS and PFS.Conclusions:CK-SBRT+TACE brought local effects that were similar to those of HR in HCC patients with a large and single lesion.Moreover,the liver injury occurrence rate was acceptable in both groups.

Creating Wheat Germplasm for High Quality Breeding by Monosomic Backcrossing

By crossing bread wheat cultlvar GC8901 with the 1D monosonlc line of Xiaoyan No. 6 and backcrosslng the offsprlng with the Xlaoyan No. 6 1D monosonlc llne for 5 years, high-molecular-welght glutenin subunlts 1Dx5＋1Dy10 from GC8901 have been transferred Into wheat cultivar Xiaoyan No. 6. The BC5F1 offspring lines had been detected by using methods of cytology, marker, molecular marker and six elite single plants with high molecular-welght glutenin subunlts： lAx1, 1Bx14＋1 By15, 1Dx5＋1 Dy10 were Identified. Those lines have high-yleld potential with better agronomic characters and have been used In high quality wheat breeding processes as well.