共查询到19条相似文献,搜索用时 62 毫秒
1.
2.
3.
目的:探讨影响原发性肝细胞性肝癌(hepatocellular carcinoma,HCC)术后复发的因素,为术中术后治疗及判断预后提供依证据.方法:回顾分析1998年1月~2005年6月,我院94例HCC术后复发病例的临床和病理资料,将病人分为近期复发(≤2年)和远期复发(》2年)两组,分析比较两组患者的性别、年龄、初诊症状、HBsAg、肝功能Child分级、AFP值、肝硬化、肿瘤病灶、肿瘤大小、肿瘤包膜、血管侵犯和转移、手术切缘、病理分级、术后综合治疗、再次手术和术中出血量等在近远期复发有无差异.结果:肝癌术后2年内和2年后复发在肿瘤大小、肿瘤包膜、血管侵犯和转移、手术切缘、术中出血量、术后综合治疗以及再次手术的差异有统计学意义,是复发的危险因素;而在性别、年龄、初诊症状、HBsAg,肝硬化、肝功能Child分级、AFP值、肿瘤病灶和病理分级上的差异无统计学意义.结论:影响HCC肝切除术后近期和远期复发的临床和病理因素可能不同,早期发现肝癌,规范的手术切除,减少手术出血量,术后复发采取综合治疗是改善患者预后的重要措施. 相似文献
4.
5.
6.
电气设备红外诊断相对温差判别法影响因素分析 总被引:4,自引:0,他引:4
根据红外辐射理论和红外热像仪的测温原理,推导了相对温差影响因素的计算公式;分析了环境温度、物体表面发射率和红外热像仪工作波段对相对温差的影响,得出了环境温度对相对温差影响较小,设备表面发射率对相对温差有一定影响,在相同条件下,使用长波热像仪测温对相对温差影响较小的结论. 相似文献
7.
8.
本文提出在论证复杂武器平台通信设备接收灵敏度时,需要特别注意“环境温度、外部电磁环境干扰”等容易忽视的因素。并通过理论计算推导得到外部环境噪底与接收机内部噪声系数之间的关系,可直接指导应用于复杂武器平台中无线通信设备接收机设计时灵敏度指标的提出与核算。 相似文献
9.
10.
数值分析了大功率半导体激光器模块的散热特性及温度场,以及焊料、热沉、导热胶和冷水板温度等参数对芯片内部最高温度的影响.结果表明,焊料厚度小于24 μm时,其导热系数对芯片内部最高温度影响较弱,无高阻层形成;芯片内部最高温度随着热沉长或宽尺寸及导热系数的增大,呈指数形式下降,随着热沉厚度的增大呈对数形式升高;当导热胶导热系数大于20 W/(m·K)、厚度小于30μm时,芯片温度趋于稳定;冷水板温度与芯片内部最高温度呈比例系数为1的线性相关性.根据分析结果提出了激光器封装部件的尺寸、导热系数或材料的设计和选择原则. 相似文献
11.
12.
Censoring is almost mandatory, especially in dealing with costly sophisticated items in a life testing experiment. Assuming the survival times to be distributed exponentially with two parameters we have proposed an estimator using a preliminary test of significance for the estimation of average survival time of the time censored life data. The bias and mean square error of the proposed estimator have been studied. Based on some mathematical results and an empirical study, recommendations have been made regarding the use of proposed estimator. 相似文献
13.
14.
Ajit Chaturvedi 《Microelectronics Reliability》1996,36(1):91-96
The problems of confidence interval estimation are considered (a) for estimating the mean of a one-parameter exponential distribution and (b) for estimating the reliability function associated with the one-parameter exponential distribution. For the estimation problem (a), the confidence interval of ‘preassigned width and coverage probability’ is considered. For the estimation problem (b), the confidence interval of ‘fixed-ratio width and preassigned coverage probability’ is proposed. The failure of the fixed sample size procedures to deal with these estimation problems is established and sequential procedures are proposed to deal with them. The proposed sequential procedures are proved to be ‘asymptotically efficient and consistent’ in the Chow-Robbins [Chow and Robbins, Ann. Math. Statist. 36,457–462 (1965)] sense. Asymptotic distributions of the stopping times are derived and second-order approximations are obtained for the average sample numbers associated with them. 相似文献
15.
16.
肝癌是我国位居第二的恶性肿瘤,死亡率高,预后差。蛋白质组学作为一门新兴学科在临床医学及疾病的诊治等方面得到了广泛运用,在肝癌的诊断和治疗中也发挥了重要作用。可通过比较恶性肿瘤与正常组织之间蛋白质组学的表达差异,提供发现肝癌肿瘤标志物的新依据,为肝癌治疗提供新的靶点。 相似文献
17.
A simulation model is proposed for boron diffusion in silicon. It is especially useful for analyzing the short time annealing process subsequent to ion implantation. This model takes into account nonequilibrium diffusion and reactions of point defects and defect-dopant pairs, considering their charge states, and the dopant inactivation by the introduction of a boron clustering reaction. It is assumed that the boron-interstitial-silicon pair (BI) is a dominant diffusion species that contributes to the total boron diffusion. A primary model parameter, the binding energy of BI, is determined and used to reproduce the equilibrium gaseous source diffusion data. Using a single set of reasonable parameter values, the model covers not only the equilibrium diffusion conditions, from intrinsic, but also the nonequilibrium postimplantation diffusion. Experimental boro distribution profiles can be accurately reproduced. It is shown that the time constant for the BI dissociation reaction rules the transient behavior of boron diffusion enhancement during postimplantation annealing 相似文献
18.
E. V. Sidak D. A. Smirnov B. P. Bezruchko 《Journal of Communications Technology and Electronics》2017,62(3):241-250
The problem of interval estimation of the time delay of the coupling between oscillatory systems from observed time series is considered. It is shown that the known asymptotic estimates based on the empirical model in the form of a system of first-order phase oscillators and the maximum likelihood formalism can lead to false inferences of the value of the time delay in two typical situations: 1) nonlinear low-dimensional systems whose phases are well-determined but, as a result of significant amplitude fluctuations, the phase approximation is insufficient for describing the dynamics and 2) systems whose phases are defined not quite well because of too large amplitude fluctuations. A method for empirical diagnostics of problematic situations and its modification (coarse estimation) providing a low probability of false inferences in these situation are proposed. The efficiency of the diagnostic criterion and coarse estimation suggested is demonstrated on reference systems with different dynamic properties (linear stochastic oscillators, van der Pol oscillators, and Ressler and Lorenz chaotic systems). 相似文献
19.