Sustained heavy ethanol drinking is a common problem globally and ethanol is one of the most abused drugs among individuals of different socio-economic status including the HIV-infected patients on antiretroviral drug...Sustained heavy ethanol drinking is a common problem globally and ethanol is one of the most abused drugs among individuals of different socio-economic status including the HIV-infected patients on antiretroviral drugs. Ethanol is reward drug and a CNS depressant especially at high doses. The study determined the effect of sustained heavy ethanol drinking by HIV-infected patients on d4T/3TC/NVP regimen on CD4+ cell counts in Uganda using WHO AUDIT tool and chronic alcohol-use biomarkers. A case control study using repeated measures design with serial measurements model was used. The patients on stavudine (d4T) 30 mg, lamivudine (3TC) 150 mg and nevirapine (NVP) 200 mg and chronic alcohol use were recruited. A total of 41 patients (20 in alcohol group and 21 in control group) were screened for chronic alcohol use by WHO AUDIT tool and chronic alcohol use biomarkers. They were followed up for 9 months with blood sampling done at 3 months intervals. CD4+ cell count was determined using Facscalibur Flow Cytometer system. Results were then sorted by alcohol-use biomarkers (GGT, MCV and AST/ ALT ratio). Data were analysed using SAS 2003 version 9.1 statistical package with repeated measures fixed model and the means were compared using student t-test. The mean CD4+ cell counts in all the groups were lower than the reference ranges at baseline and gradually increased at 3, 6 and 9 months of follow-up. The mean CD4+ cell counts were higher in the control group as compared to the chronic alcohol use group in both WHO AUDIT tool group and chronic alcohol-use biomarkers group though there was no significant difference (p > 0.05). Chronic alcohol use slightly lowers CD4+ cell count in HIV-infected patients on d4T/3TC/NVP treatment regimen.展开更多
与传统的雾化制粉技术不同,电极感应熔炼气体雾化(EIGA)技术是采用预合金棒料为电极,无坩埚感应加热,熔化后直接滴落雾化区被惰性气体雾化的技术.该技术由于在熔炼过程中液态金属与坩埚不接触,有效地减少了钛合金粉末中的夹杂物,改善了...与传统的雾化制粉技术不同,电极感应熔炼气体雾化(EIGA)技术是采用预合金棒料为电极,无坩埚感应加热,熔化后直接滴落雾化区被惰性气体雾化的技术.该技术由于在熔炼过程中液态金属与坩埚不接触,有效地减少了钛合金粉末中的夹杂物,改善了合金粉末的质量.本文利用自主设计制造的EIGA制粉设备,采用激光粒度分析仪、扫描电镜(SEM)、X射线衍射仪(XRD)等分析手段,研究了不同功率参数对雾化制备TC4合金粉末的粒度分布、组织形貌、空心球等的影响.研究表明:EIGA法制备的TC4合金粉末整体球形度均较好,空心球缺陷较少,空心球率低于3%.熔炼功率较低时,粗颗粒粉末较多,且存在一定比例不规则的棒形和哑铃状粉末颗粒;当功率提高到62 k W时,细粉比例明显提高,不规则形状的粉末颗粒基本消失.随着功率的升高,粉末中的氧含量呈增加趋势,但仍基本保持在0.08%~0.10%较低范围内.功率为56 k W时,粉末松装密度最好,为2.686 g/cm3,松装密度比为60.63%,符合激光3D打印用TC4钛合金粉末松装密度比要求.展开更多
采用冷金属过渡(Cold metal transfer,CMT)焊接技术制备了TC4钛合金件,研究了TC4钛合金增材体的显微组织和力学性能。结果表明:TC4钛合金打印态的表面成形良好,电弧3D打印TC4钛合金高度方向宏观组织上为外延生长的粗大β柱状晶形态,组...采用冷金属过渡(Cold metal transfer,CMT)焊接技术制备了TC4钛合金件,研究了TC4钛合金增材体的显微组织和力学性能。结果表明:TC4钛合金打印态的表面成形良好,电弧3D打印TC4钛合金高度方向宏观组织上为外延生长的粗大β柱状晶形态,组织由α相和β相组成。增材体的顶部为针状马氏体区,中部为细小的层片状网篮组织,基材结合处主要由层片状组织、β相以及少量残余α'相组成。所制备的成形件硬度较基材的高,表层部分硬度最大。室温拉伸性能呈现出明显的各向异性,水平方向拉伸强度较高,沿增材高度方向的塑性较高。室温冲击韧度未呈现出明显的各向异性,Aku2均达到70 J/cm2。展开更多
文摘Sustained heavy ethanol drinking is a common problem globally and ethanol is one of the most abused drugs among individuals of different socio-economic status including the HIV-infected patients on antiretroviral drugs. Ethanol is reward drug and a CNS depressant especially at high doses. The study determined the effect of sustained heavy ethanol drinking by HIV-infected patients on d4T/3TC/NVP regimen on CD4+ cell counts in Uganda using WHO AUDIT tool and chronic alcohol-use biomarkers. A case control study using repeated measures design with serial measurements model was used. The patients on stavudine (d4T) 30 mg, lamivudine (3TC) 150 mg and nevirapine (NVP) 200 mg and chronic alcohol use were recruited. A total of 41 patients (20 in alcohol group and 21 in control group) were screened for chronic alcohol use by WHO AUDIT tool and chronic alcohol use biomarkers. They were followed up for 9 months with blood sampling done at 3 months intervals. CD4+ cell count was determined using Facscalibur Flow Cytometer system. Results were then sorted by alcohol-use biomarkers (GGT, MCV and AST/ ALT ratio). Data were analysed using SAS 2003 version 9.1 statistical package with repeated measures fixed model and the means were compared using student t-test. The mean CD4+ cell counts in all the groups were lower than the reference ranges at baseline and gradually increased at 3, 6 and 9 months of follow-up. The mean CD4+ cell counts were higher in the control group as compared to the chronic alcohol use group in both WHO AUDIT tool group and chronic alcohol-use biomarkers group though there was no significant difference (p > 0.05). Chronic alcohol use slightly lowers CD4+ cell count in HIV-infected patients on d4T/3TC/NVP treatment regimen.
文摘与传统的雾化制粉技术不同,电极感应熔炼气体雾化(EIGA)技术是采用预合金棒料为电极,无坩埚感应加热,熔化后直接滴落雾化区被惰性气体雾化的技术.该技术由于在熔炼过程中液态金属与坩埚不接触,有效地减少了钛合金粉末中的夹杂物,改善了合金粉末的质量.本文利用自主设计制造的EIGA制粉设备,采用激光粒度分析仪、扫描电镜(SEM)、X射线衍射仪(XRD)等分析手段,研究了不同功率参数对雾化制备TC4合金粉末的粒度分布、组织形貌、空心球等的影响.研究表明:EIGA法制备的TC4合金粉末整体球形度均较好,空心球缺陷较少,空心球率低于3%.熔炼功率较低时,粗颗粒粉末较多,且存在一定比例不规则的棒形和哑铃状粉末颗粒;当功率提高到62 k W时,细粉比例明显提高,不规则形状的粉末颗粒基本消失.随着功率的升高,粉末中的氧含量呈增加趋势,但仍基本保持在0.08%~0.10%较低范围内.功率为56 k W时,粉末松装密度最好,为2.686 g/cm3,松装密度比为60.63%,符合激光3D打印用TC4钛合金粉末松装密度比要求.
文摘采用冷金属过渡(Cold metal transfer,CMT)焊接技术制备了TC4钛合金件,研究了TC4钛合金增材体的显微组织和力学性能。结果表明:TC4钛合金打印态的表面成形良好,电弧3D打印TC4钛合金高度方向宏观组织上为外延生长的粗大β柱状晶形态,组织由α相和β相组成。增材体的顶部为针状马氏体区,中部为细小的层片状网篮组织,基材结合处主要由层片状组织、β相以及少量残余α'相组成。所制备的成形件硬度较基材的高,表层部分硬度最大。室温拉伸性能呈现出明显的各向异性,水平方向拉伸强度较高,沿增材高度方向的塑性较高。室温冲击韧度未呈现出明显的各向异性,Aku2均达到70 J/cm2。
