如何正确运用t检验——线性回归模型中参数与0比较t检验及SAS实现

本文目的是介绍t检验在简单线性回归分析和多重线性回归分析中参数与0之间差异性比较时的理论依据和应用实践。首先介绍线性回归分析中t检验的基本原理和计算公式;然后用SAS程序分别对2个实例进行简单线性和多重线性回归分析,提请读者着重关注输出结果中有关"参数假设检验部分的检验统计量的名称及结果";最后对结果进行解释和讨论。     

临床医生药事服务工作量测算研究

目的探讨科学的药事服务工作量测算方法,以某三甲医院为例测算临床医生药事服务工作量,为决策者提供方法和数据支持。方法采用文献查阅、头脑风暴和专家咨询法确定测量参数和测算方法,通过调查获取药事服务工作量数据,运用SPSS 17.0软件对数据进行统计分析。结果临床医生药事服务工作量的量化参数为"工作时间"和"价值含量",不同职称和学历的调查对象对药事服务工作量的评估没有统计学差异(P>0.05)。结论药事服务工作量点数受医生职称、学历和工作地点等因素的影响较小,研究所探讨的量化参数和测算方法具有一定的可行性和科学性,但有待进一步论证和实践。     

Validation of a 1D patient-specific model of the arterial hemodynamics in bypassed lower-limbs: Simulations against in vivo measurements

The validation of a coupled 1D–0D model of the lower-limb arterial hemodynamics is presented. This study focuses on pathological subjects (6 patients, 72.7 ± 11.1 years) suffering from atherosclerosis who underwent a femoro-popliteal bypass surgery. The 1D model comprises four vessels from the upper-leg, peripheral networks are modeled with three-element windkessels and in vivo velocity is prescribed at the inlet.The model is patient-specific: its parameters reflect the physiological condition of the subjects. In vivo data are acquired invasively during bypass surgery using B-mode ultrasonography and catheter.Simulations from the model compare well with measured velocity (u) and pressure (p) waveforms: average relative root-mean-square error between numerical and experimental waveforms are limited to ?_p = 9.6%, ?_u = 16.0%. The model is able to reproduce the intensity and shape of waveforms observed in different clinical cases. This work also details the introduction of blood leakages along the pathological arterial network, and the sensitivity of the model to its parameters.This study constitutes a first validation of a patient-specific numerical model of a pathological arterial network. It presents an efficient tool for engineers and clinicians to help them improve their understanding of the hemodynamics in diseased arteries.     

红花注射液在大耳兔体内药动参数的测定

目的:测定红花注射液的体内药动学参数.方法:高效液相色谱法测量大耳免静脉滴注试药后不同时间的血药浓度,通过药物代谢动力学软件(3P98)进行分析研究.结果:获得静脉滴注红花注射液的主要成份羟基红花黄色素A(HSYA)的药物动力学参数.结论:HSYA在大耳免体内呈现开放二室动力学模型特征.     

多轴向旋转DSA在肢体血管诊疗中的应用

目的：探讨多轴向旋转DSA在肢体血管造影中的应用价值。方法：应用PHILIPS V5000数字成像系统对58例四肢血管行多轴向旋转DSA检查,并作回顾性分析。结果：58例旋转DSA影像均避开了多支血管的相互重叠,较好地显示病变处血管的起源、走向、分布、轮廓及假性动脉瘤的瘘口。结论：多轴向旋转DSA技术能更好地显示病变的供血血管和分支结构,多方位、清晰地显示迂曲血管分支的走行、正常解剖和异常改变,是对常规血管造影的重要补充。     

SPF级Balb/c小鼠脏器质量、脏器系数、血常规、血生化指标的测定与比较

背景：实验动物重要基础数据的标准化测定,是实行动物标准化监督管理的重要依据。 目的：测定SPF级Balb/c小鼠主要脏器质量、脏器系数、血常规、血生化指标,并进行比较。 方法：取18 g左右Balb/c小鼠240只,雌雄各半,饲养1周后,精确称量体质量和主要脏器质量,计算脏器系数,并检测血常规及血生化指标。 结果与结论：雌性与雄性Balb/c小鼠比较：①肺、脾、双肾、心、膀胱质量差异有显著性意义(P < 0.01或 P < 0.05)。②肺、脾、双肾、膀胱脏器系数差异有显著性意义(P < 0.01或 P < 0.05)。③白细胞、单核细胞、嗜碱性粒细胞百分比、红细胞、血红蛋白、红细胞平均血红蛋白浓度、红细胞分布宽度、嗜酸性粒细胞百分比差异有显著性意义(P < 0.01或 P < 0.05)。④总蛋白、白蛋白、白球比、血糖、肌酐、尿酸、三酰甘油、总胆固醇、低密度脂蛋白、高密度脂蛋白、铁、磷、尿素氮差异有显著性意义(P < 0.01或 P < 0.05)。说明性别对SPF级Balb/c小鼠主要脏器、主要脏器系数、血常规、血生化指标有影响。     

哮喘儿童肺通气功能检测的临床分析

目的：通过监测哮喘儿童急性发作期与缓解期肺通气功能各指标变化情况,了解其在儿童哮喘病情评估及指导治疗中的作用。方法应用德国Jaeger Master Screen肺功能仪对43例5～12岁哮喘急性发作期和经治疗后进入缓解期的哮喘儿童进行肺通气功能检测,包括大气道指标（ FVC、FEVl、FEV1/FVC、PEF）及小气道指标（ FEF25、FEF50、FEF75、MMEF75/25）,同时收集哮喘患儿病史资料和治疗情况。结果哮喘急性发作期患儿肺功能指标FVC、FEV1、FEV1/FVC、PEF与缓解期及健康对照组儿童比较,差异有统计学意义（ P＜0.01）;哮喘缓解期患儿的FVC、FEV1、PEF与健康对照组比较,差异无统计学意义（ P＞0.05）。小气道功能指标FEF25、FEF50、FEF75、MMEF75/25在哮喘急性发作期患儿中均明显降低,与缓解期组及健康对照组儿童相比差异有统计学意义（ P＜0.01）;哮喘治疗缓解期组中FEF25、FEF50、FEF75、MMEF75/25仍低于健康对照组,差异有统计学意义（ P＜0.05）。哮喘急性发作期不同严重程度患儿的肺通气功能指标（ FVC％pred、FEV1％pred、PEF％pred、FEF25％pred、FEF50％pred、FEF75％pred、MMEF75/25％pred ）随哮喘严重程度增加各指标越低,差异有统计学意义（ P＜0.05）。结论哮喘急性发作期肺通气功能受损,治疗缓解后小气道肺功能指标仍低于正常。肺通气功能的小气道功能指标在儿童哮喘的病情评估及治疗监测指导中意义更大。     

Identification of <Emphasis Type="Italic">I</Emphasis><Subscript>Kr</Subscript> Kinetics and Drug Binding in Native Myocytes

Determining the effect of a compound on I _Kr is a standard screen for drug safety. Often the effect is described using a single IC₅₀ value, which is unable to capture complex effects of a drug. Using verapamil as an example, we present a method for using recordings from native myocytes at several drug doses along with qualitative features of I _Kr from published studies of HERG current to estimate parameters in a mathematical model of the drug effect on I _Kr. I _Kr was recorded from canine left ventricular myocytes using ruptured patch techniques. A voltage command protocol was used to record tail currents at voltages from −70 to −20 mV, following activating pulses over a wide range of voltages and pulse durations. Model equations were taken from a published I _Kr Markov model and the drug was modeled as binding to the open state. Parameters were estimated using a combined global and local optimization algorithm based on collected data with two additional constraints on I _Kr I–V relation and I _Kr inactivation. The method produced models that quantitatively reproduce both the control I _Kr kinetics and dose dependent changes in the current. In addition, the model exhibited use and rate dependence. The results suggest that: (1) the technique proposed here has the practical potential to develop data-driven models that quantitatively reproduce channel behavior in native myocytes; (2) the method can capture important drug effects that cannot be reproduced by the IC₅₀ method. Although the method was developed for I _Kr, the same strategy can be applied to other ion channels, once appropriate channel-specific voltage protocols and qualitative features are identified. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

基于神经网络的人中耳内边界参数识别

目的 研究识别中耳内边界的方法。方法 利用CT获取耳部结构临床资料建立数值模型;利用Matlab建立神经网络识别程序。结果 利用数值模型,在鼓膜外侧施加105dB声压,进行谐响应分析获取训练样本;利用训练成熟的网络识别了中耳内边界参数。结论 数值识别结果表明,所建的中耳内边界参数识别方 法具有良好的识别精度和较快的收敛速度。