Confidence limits for Weibull parameters estimated using linear least squares analysis

Confidence limits (at selected levels of 68.27%, 90%, 95% and 99%) for unbiased estimation of Weibull parameters obtained using linear least squares (LLS) analysis were investigated in this paper. A Monte Carlo procedure was used to obtain probability distributions for unbiased estimates of Weibull modulus, m, and Weibull scale parameter, S_o, as a function of total specimen number, N (10 ≤ N ≤ 200), and m (1 ≤ m ≤ 25). Inspection of the probability distributions indicated that confidence limits for m depended only on N whereas those for S_o depended on both N and m. Whilst the determination of confidence limits for m proved to be relatively straightforward, the respective values for S_o were obtained by fitting an empirical equation to the S_o probability distributions approximated by a Gaussian curve. Example values of m and S_o confidence limits for selected N have been presented in this work.     

临床护理路径在脑出血患者护理中的应用

目的 探讨临床护理路径在脑出血患者中的应用价值.方法 选取120例脑出血患者为研究对象,将其按不同的护理方法分为2组.观察组（n=60）采用临床护理路径进行护理,对照组（n=60）采用传统的护理模式进行护理,观察2组患者对护理的满意度及相关临床指标.结果 观察组在技术质量安全、服务及时、健康教育、人文关怀、服务态度、出入院教育等方面满意度明显优于对照组（P＜0.01）;观察组患者住院时间、住院费用、并发症发生率均明显少于对照组（P＜0.01）;出院后3个月观察组FIM评分和Fugl-Meyer评分明显高于对照组（P＜0.01）.结论 临床护理路径在脑出血护理中是一种有效的护理模式,可以有效提高患者满意度和临床疗效.     

人参皂苷诱导骨髓间充质干细胞对急性肝功能衰竭大鼠肝组织再生及Wnt/β-catenin信号表达的影响

目的:分析人参皂苷诱导骨髓间充质干细胞（BMSC）对急性肝功能衰竭（ALF）大鼠肝组织再生及Wnt/β-catenin信号表达的影响。方法:选取SPF级Wistar雄性大鼠66只,其中1只行BMSCs培养,随机选取50只大鼠制备ALF模型,24 h后随机选取其中5只断颈处死,依据大鼠肝功能与组织病理学判别其是否成功造模。剩余15只大鼠将等剂量0.9%氯化钠溶液腹腔注入,作为正常组。成功造模的45只大鼠随机分成3组,分别为BMSCs组、模型组及人参皂苷诱导BMSCs组,每组各15只。造模后6 h,模型组和正常组大鼠由尾静脉注入1 mL细胞培养液,BMSCs组注入1 mL BMSCs悬液（细胞浓度2.0×109/L）,人参皂苷诱导BMSCs组注入1 mL人参皂苷诱导分化BMSCs悬液（细胞浓度2.0×109/L）,连续给药10 d。观察大鼠肝脏组织病理状况,血清总胆红素（TBil） 、AST、ALT、TNF-α、IL-6含量,肝组织内Wnt7b、Wnt7a及Wnt2基因表达。结果:正常组大鼠肝细胞无坏死、变性,整齐排列,肝小叶结构清晰,汇管区内没有炎性细胞浸润;模型组大鼠肝细胞表征为广泛坏死,肝小叶内全部肝细胞溶解坏死,网状的支架发生塌陷,汇管区和周边存在大量粒细胞、单核细胞与淋巴细胞的浸润,残余肝细胞变性、肿胀且伴随胆汁淤积;BMSCs组及人参皂苷诱导BMSCs组大鼠肝小叶结构趋向完整,肝细胞坏死、变性数量减少,汇管区内有少许炎性细胞浸润,人参皂苷诱导BMSCs组又优于BMSCs组。和正常组相比,模型组大鼠血清TBil、AST、ALT、IL-6及TNF-α含量上升;和模型组相比,BMSCs组、人参皂苷诱导BMSCs组大鼠血清TBil、AST、ALT、IL-6及TNF-α含量降低;和BMSCs组相比,人参皂苷诱导BMSCs组大鼠血清TBil、AST、ALT、IL-6及TNF-α含量降低,差异有统计学意义（P＜0.05）。和正常组相比,模型组大鼠肝组织内Wnt7b、Wnt7a、Wnt2 mRNA相对表达量降低;和模型组相比,BMSCs组、人参皂苷诱导BMSCs组大鼠肝组织内Wnt7b、Wnt7a、Wnt2 mRNA相对表达量升高;和BMSCs组相比,人参皂苷诱导BMSCs组大鼠肝组织内Wnt7b、Wnt7a、Wnt2 mRNA相对表达量升高,差异有统计学意义（P＜0.05）。结论:人参皂苷诱导BMSCs可显著改善ALF大鼠肝功能,其作用机制可能为激活Wnt/β-catenin信号通路加速肝脏再生。     

视频流广播协议的研究和建模

以准视频点播技术为背景,通过对该技术的核心要素--VoD广播协议族进行归纳、分析,并设计了一个新的数学模型--宝塔模型,并由该模型出发分析了N-VoD系统的性能与特点.该模型在一个8 MHz模拟频道上传输4套数字节目,其点播最大延迟为8 s,大大缩短了用户等待时间.     

The structure of kinks at dislocation interphase boundaries and their role in boundary migration—I. Experimental observation of kink motion

The role of kinks in dislocation ledge motion during precipitation of γ′ plates in an Al-Ag alloy was studied by conventional, high-resolution and in situ hot-stage TEM techniques. It is shown that kinks are necessary for motion of the dislocation interphase boundary and that kinks may be produced by orientation, thermal and intersection events. Analysis of the behavior of kinks at the interphase boundary utilizing isotropic dislocation theory is in reasonable agreement with experimental observations.     

高风险肝癌经皮热消融治疗中的辅助技术

随着医疗设备的发展和技术的进步,经皮热消融已成为肝癌治疗领域不可或缺的重要手段,超声是最常用的热消融引导技术,在因多种不利因素导致常规超声显示不清肝癌病灶或病灶位于极易引起严重并发症的危险部位时,经皮热消融在肝癌治疗中的应用范围受到限制。近年来一些新的辅助技术被用于克服这些高风险或困难因素,已取得了良好疗效,扩大了热消融在肝癌治疗中的适应症。本文就近年来在超声引导下对高风险肝癌进行经皮热消融治疗时所使用的辅助技术进行综述。     

Cobas6000自动生化分析仪临床检验性能评价

目的：对Cobas6000自动生化分析仪在临床生化检验中的应用效果做出总体评价。方法：检测了质控血清、样本血清中的丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、总蛋白（TP）、白蛋白（ALB）、总胆红素（TB）、血糖（Glu）、尿素氮（Bun）、肌酐（Crea）、尿酸（Uric）、肌酸激酶（CK）、钾（K）、钠（Na）、氯（CI）、钙（Ca）等项目;考察了精密度、线性相关性和回收入率,并与Vitros950干化学全自动生化分析仪做了相关性分析。结果：批内变异系数为0．61％～2．36％,批间变异系数为0．81％～4．54％;标本的稀释度与测定的浓度值线性相关性较好;Cobas6000的测定结果与强生Vitros950相比,具有良好的相关性,相关系数r2在0．9624～0．9975之间;回收率为95％～105％。结论：该仪器对血清各项生化指标的测定结果稳定,精密度和准确度均较好。     

Inhibition of p53 deSUMOylation Exacerbates Puromycin Aminonucleoside-Induced Apoptosis in Podocytes

Apoptosis is a major cause of reduced podocyte numbers, which leads to proteinuria and/or glomerulosclerosis. Emerging evidence has indicated that deSUMOylation, a dynamic post-translational modification that reverses SUMOylation, is involved in the apoptosis of Burkitt’s lymphoma cells and cardiomyocytes; however, the impact of deSUMOylation on podocyte apoptosis remains unexplored. The p53 protein plays a major role in the pathogenesis of podocyte apoptosis, and p53 can be SUMOylated. Therefore, in the present study, we evaluated the effect of p53 deSUMOylation, which is regulated by sentrin/SUMO-specific protease 1 (SENP1), on podocyte apoptosis. Our results showed that SENP1 deficiency significantly increases puromycin aminonucleoside (PAN)-induced podocyte apoptosis. Moreover, SENP1 knockdown results in the accumulation of SUMOylated p53 protein and the increased expression of the p53 target pro-apoptotic genes, BAX, Noxa and PUMA, in podocytes during PAN stimulation. Thus, SENP1 may be essential for preventing podocyte apoptosis, at least partly through regulating the functions of p53 protein via deSUMOylation. The regulation of deSUMOylation may provide a novel strategy for the treatment of glomerular disorders that involve podocyte apoptosis.     

Comparison of diagnostic accuracy between ^18F-FDG PET and PET/CT for pulmonary neoplasm

Aimed at comparing diagnostic accuracy of 18F-FDG PET with PET/CT for pulmonary neoplasm,a study based on multi-center clinical trial of the diagnoses,in randomized and semi-blind ways,was executed from January 2006 to June 2007.It included 55 patients,i.e.16 with histopathologically proved lung tumors,16 with tuberculosis and 23 with benign lesions (inflammation,pseudotumor,granuloma,fibrosis and others).The histopathologic and clinic results were served as reference standard.Statistical significances in pulmonary nodule diagnosis between 18F-FDG PET and PET/CT were determined with 95% confidence interval obtained by ROC analysis.The 18F-FDG PET detected lung neoplasm with a sensitivity of 87.5% (14/16),a specificity of 59.0% (23/39),an accuracy of 67.3% (37/55) and a positive-likelihood ratio of 2.13.The 18F-FDG PET/CT detected lung neoplasm with a sensitivity of 93.8% (15/16),a specificity of 61.5% (24/39),an accuracy of 70.9% (39/55) and a positive-likelihood ratio of 2.43.The area under curves (AUC) of 18F-FDG PET and PET/CT were 0.803±0.068 and 0.799±0.063,respectively.It can be concluded that the diagnostic accuracy for malignant pulmonary nodules between 18F-FDG PET and PET/CT was not statistically different.     

头臂动脉夹层逆行撕裂至主动脉的治疗

目的对头臂分支动脉夹层逆行撕裂至主动脉的罕见病例进行初步探讨。方法近来收治并手术的3例患者,1例为特发性颈动脉夹层,2例为医源性锁骨下动脉夹层,均保守治疗无效而行手术,分别采用腔内治疗和外科旁路手术方法。结果患者术后疼痛明显改善,术后随访复查CTA显示头臂动脉夹层稳定,假腔内血栓形成。结论对于累及主动脉的头臂动脉夹层,腔内治疗和开放手术均为可采用的方法。