期刊文献+
共找到5篇文章
< 1 >
每页显示 20 50 100
Morphometric Studies of Human Coronary Artery Trees in Healthy and Disease
1
作者 Xueping Chen Jiangguo Lin +1 位作者 Ying Fang Jianhua Wu 《医用生物力学》 EI CAS CSCD 北大核心 2019年第A01期118-119,共2页
Objective According to the report from American Heart Association(AHA),cardiovascular diseases(CVDs)are the leading causes of death globally,and coronary artery disease(CAD),known as coronary atherosclerotic plaques,a... Objective According to the report from American Heart Association(AHA),cardiovascular diseases(CVDs)are the leading causes of death globally,and coronary artery disease(CAD),known as coronary atherosclerotic plaques,accounts for over 30%of cardiovascular diseases.Therefore,it is of great clinical significance to study the relationship between coronary bifurcations morphometrical feature change and coronary artery disease.Although coronary atherosclerosis has been extensively investigated,there is a lack of in-deep study on the differences in morphometric features between optimal and realistic geometry of coronary arterial trees.The purpose of the present paper is to determine the morphological changes in patients with CAD lesion compared with non-coronary artery disease(non-CAD)subjects.Methods Due to the difficulty of studying the coronary bifurcations in vivo,image-based in vitro anatomical 3D models have been widely used as a noninvasive method for morphometric measurement and clinical diagnosis of the coronary bifurcations.With the development of coronary computed tomography angiography(CTA)hardware and software technologies,the CTA imaging technique has been shown a promising application in the characterization,visualization,and identification of coronary artery disease in recent decades.The CTA images used to reconstruct three-dimensional(3D)coronary arterial trees are from Asia populations(Southern Chinese populations),including five cadavers without CAD lesion and 102 patients with CAD lesion.The best fit artery diameter was calculated as twice the average radius between the points in the centerlines and the points on the coronary arterial inner wall.The bifurcation angles between larger daughter artery and smaller daughter artery were determined by the intersection angle of their centerlines.Murray’s law was introduced to assess the deviation of the realistic vascular networks from its optimal state.Results Based on the morphometric analysis of coronary artery bifurcations in non-CAD subjects and patients with CAD lesion subjects,the most important finding is that morphological feature parameters of non-CAD subjects are closer to the optimal values than those of patients with CAD lesion.Moreover,by comparing the morphometric data between the left and right coronary arteries,the right coronary artery exhibits a structure closer to the optimal one in morphological feature than the left coronary artery.In addition,coronary arterial trees with CAD lesion have higher asymmetry and larger area expansion ratio(AER)than those of the coronary arterial trees without CAD lesion.Conclusions We morphologically found that the coronary arterial trees with CAD lesion and left are more likely to deviate from the optimal structure predicted by Murray’s law than those without CAD lesion and right.The degree to which coronary arterial system deviating from their optimal state may directly affect the incidence of coronary artery disease.This computer morpho-logical analysis strategy is illustrated to be effective in the distinguishing of the geometric differences between the healthy and diseased coronary arteries,and the analysis method may have a large potential in cardiovascular disease earlier diagnosis. 展开更多
关键词 morphometric STUDIES Human CORONARY ARTERY Trees HEALTHY and DISEASE
在线阅读 下载PDF
Comprehensive research on Late Eocene Hulgana cf.H.ertnia(Rodentia:Ischyromyidae)
2
作者 LI Lan-Xin LI Qian 《古脊椎动物学报(中英文)》 北大核心 2025年第3期189-209,共21页
A relatively well-preserved rodent fossil,including its incisors,cheek teeth,and postcranial skeleton,was collected from the Baiyin Obo in Siziwang Banner,Nei Mongol.A multifaceted research approach was undertaken in ... A relatively well-preserved rodent fossil,including its incisors,cheek teeth,and postcranial skeleton,was collected from the Baiyin Obo in Siziwang Banner,Nei Mongol.A multifaceted research approach was undertaken in this study to conduct a comprehensive analysis on the newly discovered specimen.Based on a morphological comparison,the new specimen was identified as Hulgana cf.H.ertnia within the Ischyromyidae family.Incisive enamel microstructure analysis revealed the typical pauciserial enamel structure of Hulgana.Bone histological analysis indicates that the specimen represents a juvenile individual,which is consistent with the ontogenetic stage indicated by dental developmental stage and wear pattern.The application of geometric morphometrics to the calcaneus and bone histology of the femur and phalanx further substantiates the taxonomic classification of Hulgana as a terrestrial and cursorial rodent,exhibiting a degree of fossorial ability.This classification is analogous to that of certain extant cricetids and ground squirrels. 展开更多
关键词 Baiyin Obo Nei Mongol Late Eocene Hulgana geometric morphometrics locomotion enamel microstructure bone histology
在线阅读 下载PDF
几何形态学对8种扇贝的形态分类的应用 被引量:1
3
作者 舒予 史令 +4 位作者 郝振林 毛俊霞 王许波 田莹 常亚青 《海洋科学》 CAS CSCD 北大核心 2022年第6期61-69,共9页
几何形态学(morphometrics)是基于笛卡尔地标点的统计分析方法,主要运用广义普鲁克分析(GPA)、薄板样条分析(TPS)、主成分分析(PCA)、典型变量分析(CVA)等方法,定量的对形态变化进行识别,结果更为客观。本研究运用几何形态学方法对8种... 几何形态学(morphometrics)是基于笛卡尔地标点的统计分析方法,主要运用广义普鲁克分析(GPA)、薄板样条分析(TPS)、主成分分析(PCA)、典型变量分析(CVA)等方法,定量的对形态变化进行识别,结果更为客观。本研究运用几何形态学方法对8种常见扇贝(栉孔扇贝Azumapecten farreri、虾夷盘扇贝Mizuhopecten yessoensis、海湾扇贝Argopecten irradians、平濑掌扇贝Volachlamys hirasei、北海道扇贝Swiftopecten swiftii、荣套扇贝Gloripallium pallium、华贵类栉孔扇贝Mimachlamys nobilis、美丽环扇贝Annachlamys striatula)间形态关系进行研究,运用界标点和半界标点对扇贝的壳盘和壳耳进行数字化标点,利用PCA、CVA、TPS方法,获得8种扇贝的形态差异并进一步分析,建立系统发育树。PCA和CVA分析结果表明可以通过几何形态测量学分析方法将8种扇贝基于形态差异进行有效区分。此外,结合TPS的分析结果,发现壳耳和壳盘在扇贝中具有种间规律性差异。通过其形态分异进行表型聚类,从结果可知:美丽环扇贝、虾夷盘扇贝和海湾扇贝距离较近,壳型有共同的特征:扇贝壳盘较椭圆,壳耳相对较小;荣套扇贝和华贵类栉孔扇贝距离较近,壳型有共同的特征:扇贝壳盘更扁平,前耳相对较大;北海道扇贝、平濑掌扇贝和栉孔扇贝与其他种类没有交集。在聚类过程中,华贵类栉孔扇贝和荣套扇贝有交集,10个标本混淆,其他标本均成功聚类,正确率为95.5%。 展开更多
关键词 几何形态测量学(morphometrics) 扇贝科 形态分类 系统发育
在线阅读 下载PDF
Quantitative Geomorphologic Analysis to Measure Relationships and Changes Between Morphology and Forcing Agents of the Monterey Canyon System
4
作者 Francesca Chiara Pascoletti Andrea Taramelli +2 位作者 Carlo Innocenti Leonardo Disperati Ivano W.Aiello 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期222-222,共1页
This research compares submarine morphology with seismic reflection profiles as they manifest tectonics in a rapidly transform continental margin (Monterey Bay,California).We study modern submarine processes integrati... This research compares submarine morphology with seismic reflection profiles as they manifest tectonics in a rapidly transform continental margin (Monterey Bay,California).We study modern submarine processes integrating seismic reflection profiles interpretation,slope stability and liquefaction potential analyses and geomorphic change obtained by using high-resolution multibeam 展开更多
关键词 morphometric ANALYSIS seismic reflection profiles SUBMARINE CANYON SLOPE stability
在线阅读 下载PDF
Some Aspects of Ecology of Chrysichthys nigrodigitatus (Lacepede) in River Niger, Nigeria
5
作者 Nwachi 0 F 《Journal of Northeast Agricultural University(English Edition)》 CAS 2016年第3期47-53,共7页
A study on the food and feeding habit of Chrysichthys nigrodigitatus (Lacepede) was conducted in River Niger within the region of Oshimili local government area of Delta State Nigeria. A total of 90 specimens were c... A study on the food and feeding habit of Chrysichthys nigrodigitatus (Lacepede) was conducted in River Niger within the region of Oshimili local government area of Delta State Nigeria. A total of 90 specimens were collected with the help of fishermen using gill net, cast net and traps. The fish samples were immediately taken to the laboratory for analysis. Morphometric characteristics such as weight, length, condition factor, egg weight, Gonado Somatic Index (GSI) and sex ratio were determined. The stomach content was analyzed using numerical method to determine the food content. The total length of the fish sampled ranged from 14.40-44.60 cm, while the standard length varied from 11.00 cm to 47.00 cm and the fish body weight ranged between 19.00 g to 503.20 g. Sex ratio 1 female to 1 male was observed. The mean condition factor for both male and female obtained was 1.67. Of all the 90 fishes sampled, none had empty gut representing 100%. The major food items were phytoplankton, plant part and Detritus. Out of 41 females sampled, only 17 had eggs and the eggs were matured at stage IV. 展开更多
关键词 morphometric numerical method PHYTOPLANKTON sampling and condition factor
在线阅读 下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部