样本量估计与检验效能分析（七）

所谓两因素析因设计,是指试验中涉及两个试验因素,不同的试验条件数等于两个试验因素的水平数的乘积,即由试验因素的水平全面组合而成。全部受试对象被完全随机地分配到各试验条件组中去。做试验时,全部试验因素同时施加（即无先后顺序之分）;对资料进行统计分析时,试验因素地位平等（即不存在主次之分,也不存在嵌套关系）。本文向读者介绍采用两因素析因设计一元定量资料方差分析处理定量资料时,在试验之前如何估计样本含量与检验效能。     

如何表达与描述定量资料（四）

在医学论文中,如何正确表达与描述定量资料,对于正确选择统计学中的假设检验方法至关重要。当试验涉及两个、三个或多个因素,且这些因素之间依据专业知识和重复试验次数多少认为可以考察其各种关系时,该定量资料就属于可以考察因素之间交互作用的定量资料。根据试验设计类型和专业知识,运用恰当的方法表达和描述可以考察因素之间交互作用的多因素设计（常见的是多因素析因设计和含区组因素析因设计）的定量资料,对科学评价全部因素对观测结果的影响情况有着十分重要的意义。     

如何正确处理正交设计和均匀设计定量资料

1 引言 所有的多因素实验设计都可初分为两大类，其一为“全因子实验”，即全部实验因素的水平全面组合，这种设计被称为“析因设计”（要求在各组合条件下做两次以上独立重复实验）；其二为“部分因子实验”，即仅做析因设计全部实验点中的一部分。当实验涉及的多个实验因素之间的交互作用很复杂且都需要考察时．最好采用析因设计，其优点在于结论比较精确，不但能够检验各因素的主效应，还能全面检验所有因素间的各阶交互作用效应大小。但析因设计也存在着明显的缺点，     

析因设计及其统计分析方法：常用的临床试验设计及其统计分？…

1　概述实验研究中 ,实验效应往往是多个 (两个或两个以上 )因素共同作用的结果。有的表现为各个因素独立作用的结果 ,即每个因素的作用不受其它因素的影响 (如本刊第 3期拉丁方的例子 ) ;还有的表现为几个因素交互作用 (即一个因素的水平改变时 ,一个或几个因素的效应也相应有所改变 )的结果。这样就需要把几个因素及其各种水平相互结合起来进行试验 ,析因设计是能够进行这种试验的一种设计。析因设计是将两个或两个以上因素及其各种水平进行排列组合、交叉分组的试验设计。它不仅可检验每个因素各水平之间是否有差异 ,而且可检验各因素之…     

如何表达与描述定量资料（三）

在医学论文中,如何正确表达与描述定量资料,对于正确选择统计学中的假设检验方法至关重要。当试验涉及两个、三个或多个因素,且这些因素之间依据专业知识和重复试验次数多少认为可以考察其各种关系时,该定量资料就属于可以考察因素之间交互作用的定量资料。根据试验设计类型和专业知识,运用恰当的方法表达和描述可以考察因素之间交互作用的多因素设计（常见的是析因设计和重复测量设计）的定量资料,对科学评价全部因素对观测结果的影响情况有着十分重要的意义。     

可以考察交互作用的多因素试验设计类型

可以考察交互作用的试验设计类型有很多，包括析因设计、含区组因素的析因设计、重复测量设计、正交设计、裂区设计等。在所有可以考察交互作用的试验设计类型中，析因设计是最受研究者青睐的一种试验设计类型。析因设计也称全因子试验设计，即试验中涉及所有因素水平全面组合形成的试验条件，各试验条件下做k次独立重复试验。含区组因素析因设计，比析因设计多考察1个或多个重要非试验因素（即区组因素）对观测结果的影响。本文通过实例具体介绍析因设计及含区组因素的析因设计。     

如何表达与描述定量资料（五）

在生物医学科研中,经常会涉及多因素试验研究问题,若科研经费充足,人力和时间都允许,选择多因素析因设计来安排试验是非常好的,因为此设计类型可以分析各因素不同水平对结果的影响,还可分析全部因素各级交互作用对结果的影响。然而,当前面所提到的条件不允许时,就需要选用正交设计。有时,选用正交设计仍感到试验次数过多,     

用简捷公式分析各次组观察数不成比例的2~2析因设计

析因试验在医学研究中常用于病原调查、药物联合作用的评价以及实验条件的分析等。一个较简单的2~p析因设计是p个因子各具2个水平,由于这类设计的主效因及交互作用各仅有一个自由度,因此可利用正交系数以简化计算。但一般要限制各次组的观察数为1个或者成比例。当各次组的观察数不全相等且不成比例时,要分析各因子的主效应     

如何正确识别和处理几种易混淆的多因素设计定量资料（一）

1引言 随着科研工作的深入发展，科研人员在实验时所考虑的实验因素或重要非实验因素越来越多，多因素实验设计也应用更加频繁．所得的统计结果说服力也更强。但一些科研人员在应用多因素实验设计时，不考虑实验中涉及的因素性质、因素个数、因素之问的重要程度、因素进入实验的顺序和受试对象之间是否存在内在关联等因素的影响，随意套用析因设计等定量资料的方差分析处理定量资料，是万万不可取的。     

医学论文中统计分析错误辨析与释疑(8)--定量资料统计分析方法的合理选择

析因设计也叫做全因子实验设计，就是实验中所涉及到的全部实验因素的各水平全面组合形成不同的实验条件，每个实验条件下进行两次或两次以上的独立重复实验。析因设计的最大优点是所获得的信息量很多，可以准确地估计各实验因素的主效应的大小，还可估计因素之间各级交互作用效应的大小；     

Value of D-Dimers in patients with acute aortic dissection

Objective: To evaluatel the value of D-dimers in patients with acute aortic dissection (AAD). Methods: This study consisted of 16 patients with AAD and 27 non-AAD patients. Serum D-dimets were measured by Sta-Liatest D-DI immunoturbidimetric assay. Results: D-dimer level was higher (P ＜ 0.001) in patients with AAD(7.91 ± 5.52 μg/ml) than that in non- AAD group(1.57±1.24 μg/ml). D-dimer was positive (＞0.4 μg/ml) in all patients with AAD and in 10 control group patients (37%). Among patients with acute AAD, D-dimers tended to be higher in Stanford A than in Stanford B (8.67 ± 4.31 μg/ml vs. 3.24±1.27 μg/ml, P ＜0.01). D-dimer values tended to be higher in more extended disease(3.84 ± 1.65 μg/ml, 8.57 ± 3.58 μg/ml and 11.87 ± 5.69 μg/ml in thoracic aorta, thoracic and abdominal aorta, thoracic and abdominal aorta and iliacal arteries, respectively, P ＜ 0.05 for both 8.57 ± 3.58 and 11.87 ± 5.69 vs. 3.84 ± 1.65 ). Including the control group into the analysis, we found a sensitivity of 100%, a negative predictive value of 100%, and a specificity of 66% and a positive predictive value of 64% for D-dimer in diagnosis of AAD in our patients with suspected AAD. Conclusion: D-dimer was elevated in patients with AAD. A negative D-dimer test result could be useful in excluding AAD.     

Research of combined liver-kidney transplantation model in rats

Objective： To set up a simple and reliable rat model of combined liver-kidney transplantation. Methods： SD rats served as both donors and recipients. 4℃ sodium lactate Ringer＇s was infused from portal veins to donated livers,and from abdominal aorta to donated kidneys, respectively. Anastomosis of the portal vein and the inferior vena cava （IVC） inferior to the right kidney between the graft and the recipient was performed by a double cuff method, then the superior hepatic vena cava with suture. A patch of donated renal artery was anastomosed to the recipient abdominal aorta. The urethra and bile duct were reconstructed with a simple inside bracket. Results： Among 65 cases of combined liver-kidney transplantation, the success rate in the late 40 cases was 77.5%. The function of the grafted liver and kidney remained normal. Conclusion： This rat model of combined liver-kidney transplantation can be established in common laboratory conditions with high success rate and meet the needs of renal transplantation experiment.     

BLOOD PRESSURE CHANGE WITH AGE IN SALT-SENSITIVE TEENAGERS

Objective To observe blood pressure change with age in salt-sensitive teenagers whose salt sensitivity were determined by repeated testing.Methods Salt sensitivity was determined through intravenous infusion of normal saline combined with volume-depletion by oral diuretic furosemide in 55 teenagers. After five years, salt sensitivity was re-examined and subject blood pressure was followed up. Blood pressure changes in salt-sensitive teenagers were compared to that of non-salt sensitive teenagers over five years.Results After 5 years, the repetition rate of salt sensitivity determined by intravenous saline loading is 92.7%. In teenagers with salt sensitivity on the baseline, both the systolic blood pressure increments and increment rates were much higher than non-salt sensitive teenagers (12.7±12.1 mmHg vs. 2.8±5.2 mmHg, P＜ 0.01; 12.2%± 12.0% vs. 2.5% ±4.4%, P＜ 0.001,respectively). There was a similar trend for diastolic blood pressure (8.4 ± 6.4 mmHg vs. 3.7 ± 6.4 mmHg, P = 0.052; 13.2% ±10.6 % vs. 6.8%± 10.1%, P = 0.053, respectively).Conclusions Salt sensitivity determined by intravenous saline loading showed good reproducibility. Blood pressure increments with age were much higher in salt-sensitive teenagers than non-salt sensitive teenagers, especially in terms of systolic blood pressure.     

安心颗粒对急诊经皮冠状动脉介入术后生活质量影响的研究

目的：评价使用安心颗粒对急诊经皮冠状动脉介入术（PPCI）术后生活质量的影响.方法：将160例接受PPCI的急性ST段抬高型心肌梗死患者随机分为安心颗粒组（术前顿服安心颗粒8.8g,术后安心颗粒4.4 g/次,每日2次）和对照组（仅接受基础药物治疗）.所有患者均服用阿司匹林、氯吡格雷和阿托伐他汀.分别在入院时、出院前1d、出院后180 d时,应用心肌梗死多维度量表（MIDAS）、中文版SF-36评价量表对患者生活质量评分.并观察术后30 d以内的出血并发症、血小板减少症发生情况.结果：入院时和出院前1d,两组患者的心肌梗死MIDAS、SF-36量表评分比较无差异（P＞0.05）;出院后180 d时,与对照组比较,安心颗粒组MIDAS、SF-36评分明显减低（P＜0.05）;组内与入院时比较,两组出院前1d、出院后180 d时,MIDAS、SF-36评分均降低（P＜0.05）.两组患者在随访期间均无大量出血、少量出血、重度和极重度血小板减少症发生,安心颗粒组有4例、对照组有7例发生不明显出血（P＞0.05）.两组发生轻度血小板减少症的患者数比较无差异（P＞0.05）.结论：PPCI使用安心颗粒,能改善急性ST段抬高型心肌梗死患者的生活质量,且不增加出血风险.     

The comparative studies of the influences of Urapidil and Nicardipine on sino-atrial node function, atrio-ventricular node function and hemodynamics

Objective:To investigate the influences of urapidil and nicardipine on rabbit sinus function,atrio-ventricular node function and hemodynamics.Methods:Thirty-two Angora's rabbits were selected and randomly divided into four groups.U1 group:urapidil 0.25 mg/kg;U2 group:urapidil 0.5 mg/kg;N1 group:nicardipine 10 μg/kg;N2 group:nicardipine 20 μg/kg.All these medicine were administrated within 30 seconds.Measurements were taken before and after the administration of urapidil or nicardipine for the following data:mean blood pressure(MAP),heart rate(HR),sino-atrial conduction time(SACT),maximal sinoatrial recovery time(SNRTmax)corrected sinus node recovery time(CSNRT),index of sinus node recovery time(SNRTI),Wenckebach A-V conduction frequency (WB),and P-R interval.Results:Significant MAP and HR changes were identified in all of the four groups before and after administration of both urapidil and nicardipine.No significant changes could be found in the rest of the parameters.Intergroup analysis showed that SACT and CSNRT of N1 and N2 groups were shorter than those of the U2 group(P＜0.01);the MAP decreased(P＜0.01)and the HR increased drastically(P＜0.01).Conclusions:Neither urapidil(0.25 mg/kg,0.5 mg/kg)nor nicardipine(10μg/kg,20μg/kg)has any significant influence on rabbit sinus function or rabbit atrio-ventricular node function.Nicardipine could be a better choice than urapidil for parafunctional sinus node patients.     

Expression of OPGmRNA and ODFmRNA in the patients of hip fracture due to osteoporosis

Objective：To investigate the gene expression of osteoprotegerin（OPG） and osteoclast differentiation factor（ODF） in the bone tissue of patients with hip fracture due to osteoporosis. Methods：OPGmRNA and ODFmRNA in the bone tissue in 50 cases of osteoporosis sufferers（over 50 years old） with hip fracture（Observer Group） and 30 cases of hip facture sufferers with no osteoporosis（Control group） were analyzed with the Semi-Quantitative RT-PCR method. Results：The mRNA expressed of ODF, OPG were both high in the patients with hip fracture. In the control group, the expression of OPG mRNA was observed, while the expression of ODF mRNA was very slight. Conclusion：Aged patients contained all signals including OPG, ODF that are essential for inducing osteoclastogenesis and promoting bone resorption.     

Dynamic Changes in Serum Estradiol and Progesterone levels in Patients of Premenstrual Syndrome with Adverse Flow of Liver-qi

Objective:To probe into the influence of changes of ovarian hormones on the pathogenesis of the specific sub-type premenstrual syndrome(PMS)and reveal partial microcosmic mechanisms of adverse flow of liver-qi.Methods:Estradiol(E2)and progesterone(P)levels in serum were determined at different phases of menstrual cycle by radioimmunoassay.Results:In the group of PMS with adverse flow of liver-qi.the secretive peak value Of E2 and P at the follicular phase significantly decreased,and the secretive peak value at the luteal phase did not come into being.Conclusions:Low E2 and P secretive peak at the follicular phase and absence of secretive peak at the luteal phase is one of the microcosmic mechanisms of PMS with adverse flow of liver-qi.One of the pathophysiologic mechanisms of specific sub-type PMS is probably the continuous low level of E2and P.     

Real-time Three-dimensional Echocardiography in Assessment of Left Ventricular and Right Ventricular Volumes

Real-time three-dimensional echocardiography (RT3DE)is a new ultrasound technique that enables dynamic threedimensional visualization and quantification of the heart in real time. Investigation of feasibility and methodology of RT3DE in determining left ventricular (LV) and right ventricular (RV) volumes, RT3DE was performed in 35 normal adults using Philips SONOS 7500 system with a 2-4 MHz matrix array transducer. The 60°×60° "pyramid" volume database was obtained and analyzed on a TomTec echo workstation. Both LV and RV volumes were calculated with four 3DE methods (i.e. apical 2, 4, 8, and 16-plane) through manually tracing ventricular endocardial borders in end diastole and end systole. Stroke volumes were then calculated. LV volume was also measured by 2DE Simpson's rule using GE VIVID 7 ultrasound machine.     

SCREENING FOR A 21-CHROMOSOME ABNORMALITY IN PREIMPLANTED EMBRYOS OF ELDERLY WOMEN

Increasing maternal age is the only etiological factor unequivocally linked to Down's syndrome in humans. The occurrence rate of newborns with Down's syndrome is about 1/220 in women over 35 years old. However, the occurrence rate in embryos fertilized in vitro, of the elder woman is unclear. Using FISH we screened the number of chromosome 21 in preimplanted embryos of 5 elderly women (average age, 38.4 years) to study the feasibility and necessity of screening trisomy 21 in embryos in patients over 35 years old at the in vitro fertilization (IVF) center.     

Scientific principles and rigorous processes should be followed in developing clinical guidelines for therapeutic interventions of integrative medicine

A clinical guideline for the therapeutic interventions of integrative medicine may be defined as a written document which states a series of recommendations on therapeutic interventions of integrative medicine for a special disease or condition. The guideline may provide assistance to medical professionals in making clinical decisions aimed at improving the clinical outcome of patients and reducing the costs of medical care（~＇4~. Recommendations issued by a guideline should be based on the best available evidence in both Western and Chinese medicine. For fulfilling this purpose, the development of clinical guidelines for therapeutic interventions in the field of integrative medicine should follow scientific principles and undergo a rigorous processes.