Period-amplitude analysis and power spectral analysis: a comparison based on all-night sleep EEG recordings

Both period-amplitude analysis (PAA) and power spectral analysis (PSA) were performed on all-night human sleep EEG recordings obtained from 11 subjects. The comparison of the two methods was based on the PAA variables time in band (a wave incidence measure) and rectified amplitude, and on the PSA variables spectral power density and spectral amplitude (the square root of power). The mean time course of these variables was determined for the first 4 nonREM-REM sleep cycles. Spectral power density and spectral amplitude in the delta range were high in nonREM sleep and low in REM sleep, and showed a declining trend over consecutive nonREM sleep episodes. In the frequency range below 2 Hz, rectified amplitude was highly correlated with both time in band and spectral amplitude, and there was no evidence for a dissociation between wave amplitude and wave incidence measures. However, in frequencies above 2 Hz, the modulation of time in band was a mirror image of that below 2 Hz. This result does not reflect a property of the data, but is inherent to the methodology applied. The reversal point of modulation was merely shifted when the high-pass filter settings were changed. It is concluded that band-pass filtering is necessary prior to PAA even for the analysis of the lowest frequency range, and that the indiscriminate use of PAA may give rise to spurious results.     

《中国医学物理学杂志》1999-2003年文献计量分析

目的:对<中国医学物理学杂志>的载文特点、作者特点及引文特点等进行分析.材料与方法:应用文献计量学方法对该刊1999-2003年共5卷20期刊载的531篇论文进行统计分析.结果:该刊平均载文量为26.55篇.论文合著率达93.8%,作者合作度为3.98.基金资助论文为160篇,占30.13%.附有引文的论文占载文量的97.93%,平均引文率为7.17篇,外文引文占57.78%,引文类型主要是期刊,占78.98%.作者自引率为5.96%,期刊自引率为2.84%.普赖斯指数为45.09%,引文半衰期为5.44年.结论:<中国医学物理学杂志>已形成以高校系统为核心的研究群体,其论文质量逐步提高,作者协同科研及吸收国外先进技术的意识和能力相对较强,已成为国内有较大影响的学术期刊.     

《中国生物医学工程学报》论文作者群的分析研究

本文依据文献计量学原理，对１９８６至１９９６年间《中国生物医学工程学报》的论文作者群进行了统计、分析、归纳和研究，从中揭示出我国生物医学工程研究的现状与特点、作者所属系统的分布特点及规律；确定了作为该刊核心作者的数量和比例；又对作者的合作率、论文单元作者数及论文引文情况作了统计分析研究；同时从作者研究的角度肯定了该刊作为本学科核心期刊的合理性，希翼对该学科的发展及本刊的发展提供可参考的数据。     

生物医学工程类期刊论文的计量研究

采用科学和文献计量学方法，利用国内外著名的生物医学数据库，从数据库收录、载文量、基金来源、受资助的论文数、引文数、著者分布、机构和主题分布等方面对国内的4种生物医学工程类期刊1997～2001年间所发表的论文进行全面的统计分析。结果表明：《中国生物医学工程学报》和《生物医学工程学杂志》被国内外多种数据库收录，EI和CA收录《生物医学工程学杂志》论文较多。EI对3种期刊的录用率均呈下降趋势。CA收录《生物医学工程学杂志》论文量则呈上升趋势；《生物医学工程学杂志》产文量和基金资助论文数最多，所有基金资助类型中以国家自然科学基金为主，占61．76％；国内已经形成生物医学工程研究的核心作者和核心研究机构，研究最集中的10个主题是生物相容性材料、计算机辅助信号处理、心电描记术、计算机辅助图像处理、生物力学、算法、脑电描记术、自动数据处理、机械应力、血液动力学、数学计算、微型计算机、理论模型；研究最多的10个相关副主题概念是仪器和设备、病理生理学、诊断、治疗、超声检查、生理学、分析、外科学、病理学和方法。     

国际肝干细胞研究文献可视化分析

［摘要］ 目的 对国际肝干细胞研究文献进行可视化分析,为把握重点研究方向、选择前沿技术课题、进行科学合理的科技布局提供决策信息支持。 方法 利用文献计量学方法和信息可视化方法对Web of Science中的SCIE数据库收录的国际肝干细胞研究文献的时间、国别、机构、期刊、学科、主题进行分析。 结果 科学引文索引扩展版（SCIE）收录了1092篇肝干细胞研究文献,自2000年开始文献数量进入快速增长期;在文献数量上中国与美国、日本差距较大;肝干细胞研究属多学科交叉领域,但发表期刊相对集中;其研究基本上经历了肝干细胞的发现辨认、来源和基础应用研究阶段;研究前沿有肝干细胞的识别和移植后鉴定、参与肝再生机制、诱导分化、外源基因的表达等。 结论 中国应加大肝干细胞资金投入、加强与顶级科研院所的交流合作、自主创新,引导肝干细胞从基础研究向临床研究转化。     

Sample-size properties of a case-control association analysis of multistage SNP studies for identifying disease susceptibility genes

A two-stage association study is the most commonly used method to efficiently identify disease susceptibility genes. However, some recent single nucleotide polymorphism (SNP) studies recently utilized three-stage designs. The purpose of this study was to investigate the practical properties of statistical powers and positive predictive values (PPVs) of replication-based analysis (RBA) and the joint analysis (JA) in multistage designs. For this purpose, a program for multistage designs was developed to calculate these performance indicators under various conditions of the number of samples, alleles of candidates, alleles remaining in the final stage, and genotypings. The results showed that the powers and PPVs of RBA and JA in three-stage designs were higher than those in two-stage designs in the range of a smaller proportion of sample size than 0.5 at the first stage. This tendency was more remarkable in JA. In conclusion, researchers who perform SNP studies for identifying disease susceptibility genes need to take account of three-stage case-control association studies, corresponding to study conditions such as the total numbers of samples, alleles, and genotypings. Furthermore, the program developed in this study is useful for estimating powers and PPVs in planning multistage association studies.     

组织形态测量中的图象分析技术

医学科研和临床中的很多结论，与组织的形态变化有关。计算机图形图象技术的发展，使得组织形态的分析方法由传统的定性描述向定量分析化成为可能。本实验拟采用通用计算机组成一个显微图象分析系统，开发通用性强的分析软件，对组织和各形态完成全面，准确的定量测量。分析临床乳腺肿瘤病理切片的实验结果表明：本系统具有合理的硬件配置，基于本系统开发的分析软件不仅具有快速有效，准确灵活等特点，而且通用性好，在医学研究和临     

A state of emergency: Dominant cultural narratives on homelessness in Hawai‘i

This exploratory study aimed to identify the dominant cultural narratives on homelessness in Hawai‘i—an area of the United States that has seen a precipitous increase in homelessness amid overall national decline. Because media is a primary way in which these narratives are created, solidified, and perpetuated, this study sought to understand the role the local media played in constructing homelessness narratives during this homelessness “crisis.” This study used thematic content analysis of a random sample of 648 articles of Hawai‘i media coverage between 2012 and 2017. The analysis found that media coverage of homelessness in Hawai‘i emphasized structural-level causes and solutions, while simultaneously relying on stereotypes and stigmatizing characteristics. However, coverage became more complex over time and was open to revision based on new information. This study suggests that media could be a viable target of interventions seeking to produce healthy and accurate narratives.     

交感神经放电特征分析的研究进展

对交感神经电活动的分析方法进行分类,介绍国外各小组在交感神经放电特征的统计学分析、功率谱分析、非线性动力学分析以及和其它生理指标的多变量耦合分析方面所取得的研究进展,总结当今交感神经电活动分析上存在的问题和缺陷,并展望这一工作的发展趋势。     

Norms and correlates of bioimpedance phase angle in healthy human subjects, hospitalized patients, and patients with liver cirrhosis

This study investigates whether bioimpedance indexes rather than derived body compartments would be adequate for nutritional assessment. Evidence is provided that the phase angle as determined by conventional tetrapolar whole body bioelectrical impedance analysis at 50 kHz (1) was largely determined by the arms and legs and not the trunk, (2) was higher in control subjects than in hospitalized patients [mean (SD) 6.6° (0.6)° vs 4.9° (1.2)°, P<0.001], (3) discriminated poorly between cirrhotic patients of different Child-Pugh class, and (4) was positively correlated with muscle mass (r=0.53) and muscle strength (r=0.53) in these patients (each P<0.01). In a prospective study of patients with liver cirrhosis Kaplan-Meier and log rank analyses of survival curves demonstrated that patients with phase angles equal to or less than 5.4° had shorter survival times than patients with higher phase angles [6.6° (1.4)°] and that phase angles less than 4.4° were associated with even shorter survival times (P<0.01). The prognostic roles of the phase angle and standard nutritional parameters such as total body potassium, anthropometric measurements, and impedance derived fat free mass, body cell mass and fat mass were evaluated separately by Cox regression which eliminated all variables except the phase angle as predictors of patient survival time (P<0.01). We concluded that for the clinical assessment of patients the phase angle may be superior to commonly used body composition information. Electronic Publication     

父母养育方式及其影响因素与神经症关系的多因素分析

目的：探讨父母养育方式及其影响因素与神经症的关系。方法：采用多因素分析方法对４００例大学生神经症患者和５００名正常大学生的ＥＭＢＵ问卷结果进行量化分析,结果：神经症患者父母养育方式趋向拒绝型、偏爱型、过度保护型;母亲教育水平较低、受试者教育水平较高、有家庭不幸事件者,则子女患神经症的危险性较大;父母地位提高或受到嘉奖者子女患神经症的危险性较小。分层分析结果表明,与正常组比较神经症组的父母养育方式受父母职业和教育水平、受试者年龄、教育水平、民族及家庭社会心理因素的影响。结论：父母养育方式不当以及一些社会心理因素与神经征的发生有关。     

Correlation-based multivariate analysis of genetic influence on brain volume

Considerable research effort has focused on achieving a better understanding of the genetic correlates of individual differences in volumetric and morphological brain measures. The importance of these efforts is underlined by evidence suggesting that brain changes in a number of neuropsychiatric disorders are at least partly genetic in origin. The currently used methods to study these relationships are mostly based on single-genotype univariate analysis techniques. These methods are limited as multiple genes are likely to interact with each other in their influences on brain structure and function. In this paper we present a feasibility study where we show that by using kernel correlation analysis, with a new genotypes representation, it is possible to analyse the relative associations of several genetic polymorphisms with brain structure. The implementation of the method is demonstrated on genetic and structural magnetic resonance imaging (MRI) data acquired from a group of 16 healthy subjects by showing the multivariate genetic influence on grey and white matter.     

男大学生无气力症调查分析

目的 了解我国当代男大学生无气力症现状,为高校学生心理健康教育提供依据.方法 在借鉴日本学者研究的基础上,编制了男大学生无气力症调查问卷.对410名在校男大学生进行了初测,对调查数据进行探索性因子分析、验证性因子分析和回归分析.结果 通过探索性因子分析,表明大学生冷漠心理特征分量表由无朝气、无自我、无兴趣、强迫适应4个维度构成,共20个项目.大学生生活愿望低下分量表由学习热情低下、上课热情低下、生活热情低下3个维度构成,共15个项目.结论 验证性因子分析结果表明,上述结构是合理的.回归分析说明,男大学生冷漠心理特征对其生活愿望有一定的影响作用.     

健康心理学研究的多元解析方法

本文从对以往文献的研究方法分析出发,提出了健康心理学较新的研究方法,如过程分析,探索性因素分析,验证性因素分析,协方差结构模式和路径分析等多元统计解析方法,这些方法可以充分有效地利用量表所筹集上来的信息,逐步实现对理论模型的构建,使 多散乱的项目数据浓缩成简明概括的模型,从而使研究能向深度发展,增进研究的学术水平.     

主成分分析在基因芯片聚类分析中的适用性评估

目的探讨在基因芯片聚类分析前对数据进行主成分分析是否有助于提高聚类的准确性。方法选取3组包含大量被生物学家人为分类基因的芯片数据集Budding yeast、Saccharomyces cerevisiae、Central nervous system作为实验数据,分别计算对原数据直接聚类和提取主成分后聚类的结果,并以信息变化量为指标衡量这些结果与人为分类的匹配度。采用启发式算法搜寻最优主成分组合,比较欧几里德距离和相似系数2种距离度量方法以及层次聚类和K-重心聚类2种聚类算法的结果。结果在3组数据集中,层次聚类算法相比K-重心聚类算法效果均略好,且以主成分代替原数据进行聚类分析都没有显著提高聚类的准确性,有些情况下甚至不如后者。仅在Saccharomyces cerevisiae数据集中,当主成分个数足以覆盖原数据中90％-95％方差时,特定的主成分组合才展现出一定优势,但这种组合与主成分大小顺序并无规律可循。结论在基因芯片数据模型不清时,应避免盲目地使用数据中提取的主成分作为聚类分析的输入。     

Genetic modelling of dizygotic twinning in pedigrees of spontaneous dizygotic twins

The inheritance of spontaneous dizygotic (DZ) twinning was investigated in 1,422 three-generation pedigrees ascertained through mothers of spontaneous DZ proband twins. DZ twinning was modelled as a trait expressed only in women. The penetrance was modelled first as a parity independent and secondly as parity dependent. The observed frequencies of maternal and paternal grandmothers with DZ twins differed significantly from the expectations under an X-linked mode of inheritance. Complex segregation analysis showed that the parity-independent phenotype of “having DZ twins” was consistent with an autosomal monogenic dominant model, with a gene frequency of 0.035 and a female-specific lifetime penetrance of 0.10. Recessive, polygenic, and sporadic models were rejected. The autosomal dominant model revealed a strong robustness against a changing population prevalence and the loss of information due to the presence of same-sexed twin pairs of unknown zygosity. When DZ twinning was modelled as a parity dependent trait, the data were compatible with an autosomal dominant model with a gene frequency of 0.306 and a penetrance of 0.03 per birth for female gene carriers. © 1996 Wiley-Liss, Inc.     

Consecutive medical exome analysis at a tertiary center: Diagnostic and health‐economic outcomes

The utility of whole exome analysis has been extensively demonstrated in research settings, but its clinical utility as a first‐tier genetic test has not been well documented from diagnostic and health economic standpoints in real‐life clinical settings. We performed medical exome analyses focusing on a clinically interpretable portion of the genome (4,813 genes) as a first‐tier genetic test for 360 consecutive patients visiting a genetics clinic at a tertiary children's hospital in Japan, over a 3‐year period. Bioinformatics analyses were conducted using standard software. A molecular diagnosis was made in 171 patients involving a total of 107 causative genes. Among these 107 causative genes, 57 genes were classified as genes with potential organ‐specific interventions and management strategies. Clinically relevant results were obtained in 26% of the total cohort and 54% of the patients with a definitive molecular diagnosis. Performing the medical exome analysis at the time of the initial visit to the tertiary center, rather than after visits to pertinent specialists, brain MRI examination, and G‐banded chromosome testing, would have reduced the financial cost by 197 euros according to retrospective calculation under multiple assumption. The present study demonstrated a high diagnostic yield (47.5%) for singleton medical exome analysis as a first‐tier test in a real‐life setting. Medical exome analysis yielded clinically relevant information in a quarter of the total patient cohort. The application of genomic testing during the initial visit to a tertiary medical center could be a rational approach to the diagnosis of patients with suspected genetic disorders.     

Shape differences in the cervical and upper thoracic vertebrae in rats (Rattus norvegicus) and bats (Pteropus poiocephalus): can we see shape patterns derived from position in column and species membership?

The shapes of cervical (C1–C7) and upper thoracic (T1, T2) vertebrae from the rat and the grey-headed flying fox have been analysed by Fourier analysis to investigate the types of variation present and to try to isolate bones according to position along the vertebral column and species. It was found that the T2 vertebrae of the rat are very different from all others in the study, that C2 and C6 vertebrae are very similar and that the remaining vertebrae split according to species.     

Application of Mineralogical Techniques in the Study of Human Lithiasis

The authors review the mineralogical methods and techniques of analyzing calculi, stony concretions in the body. They discuss the main types of kidney stones (prostate, testicular, salivary, and bile) and the different diagnostic methods in mineralogy. By applying the techniques of optical microscopy and electron microscopy, they describe the different characteristics of human stones, based on extensive experience as evidenced by their numerous studies.