期刊文献+
共找到303,208篇文章
< 1 2 250 >
每页显示 20 50 100
Modulatory effect of International Standard Scalp Acupuncture on brain activation in the elderly as revealed by resting-state fMRI 预览
1
作者 Wai-Yeung Chung Song-Yan Liu +7 位作者 Jing-Chun Gao Yi-Jing Jiang Jing Zhang Shan-Shan Qu Ji-Ping Zhang Xiao-Long Tan Jun-Qi Chen Sheng-Xu Wang 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第12期2126-2131,共6页
The specific mechanisms by which acupuncture affects the central nervous system are unclear. In the International Standard Scalp Acupuncture system, acupuncture needles are applied at the middle line of the vertex, an... The specific mechanisms by which acupuncture affects the central nervous system are unclear. In the International Standard Scalp Acupuncture system, acupuncture needles are applied at the middle line of the vertex, anterior parietal-temporal oblique line, and the posterior parietal-temporal oblique line. We conducted a single-arm prospective clinical trial in which seven healthy elderly volunteers (three men and four women;50–70 years old) received International Standard Scalp Acupuncture at MS5 (the mid-sagittal line between Baihui (DU20) and Qianding (DU21)), the left MS6 (line joining Sishencong (EX-HN1) and Xuanli (GB6)), and the left MS7 (line joining DU20 and Qubin (GB7)). After acupuncture, resting-state functional magnetic resonance imaging demonstrated changes in the fractional amplitude of low frequency fluctuations and regional homogeneity in various areas, showing remarkable enhancement of regional homogeneity in the bilateral anterior cingulate, left medial frontal gyrus, supramarginal gyrus, right middle frontal gyrus, and inferior frontal gyrus. Functional connectivity based on a seed region at the right middle frontal gyrus (42, 51, 9) decreased at the bilateral medial superior frontal gyrus. Our data preliminarily indicates that the international standard scalp acupuncture in healthy elderly participants specifcally enhances the correlation between the brain regions involved in cognition and implementation of the brain network regulation system and the surrounding adjacent brain regions. The study was approved by the Ethics Committee of the China-Japan Union Hospital at Jilin University, China, on July 18, 2016 (approval No. 2016ks043). 展开更多
关键词 nerve REGENERATION RESTING-STATE FUNCTIONAL magnetic resonance imaging International Standard SCALP Acupuncture acupoint specificity brain FUNCTIONAL CONNECTIVITY healthy elderly volunteers low frequency fluctuation regional homogeneity FUNCTIONAL CONNECTIVITY neural REGENERATION
在线阅读 下载PDF
Alteration of functional connectivity in patients with Alzheimer’s disease revealed by resting-state functional magnetic resonance imaging 预览
2
作者 Jie Zhao Yu-Hang Du +2 位作者 Xue-Tong Ding Xue-Hu Wang Guo-Zun Men 《中国神经再生研究:英文版》 SCIE CAS CSCD 2020年第2期285-292,共8页
The main symptom of patients with Alzheimer’s disease is cognitive dysfunction. Alzheimer’s disease is mainly diagnosed based on changes in brain structure. Functional connectivity reflects the synchrony of function... The main symptom of patients with Alzheimer’s disease is cognitive dysfunction. Alzheimer’s disease is mainly diagnosed based on changes in brain structure. Functional connectivity reflects the synchrony of functional activities between non-adjacent brain regions, and changes in functional connectivity appear earlier than those in brain structure. In this study, we detected resting-state functional connectivity changes in patients with Alzheimer’s disease to provide reference evidence for disease prediction. Functional magnetic resonance imaging data from patients with Alzheimer’s disease were used to show whether particular white and gray matter areas had certain functional connectivity patterns and if these patterns changed with disease severity. In nine white and corresponding gray matter regions, correlations of normal cognition, early mild cognitive impairment, and late mild cognitive impairment with blood oxygen level-dependent signal time series were detected. Average correlation coefficient analysis indicated functional connectivity patterns between white and gray matter in the resting state of patients with Alzheimer’s disease. Functional connectivity pattern variation correlated with disease severity, with some regions having relatively strong or weak correlations. We found that the correlation coefficients of five regions were 0.3–0.5 in patients with normal cognition and 0–0.2 in those developing Alzheimer’s disease. Moreover, in the other four regions, the range increased to 0.45–0.7 with increasing cognitive impairment. In some white and gray matter areas, there were specific connectivity patterns. Changes in regional white and gray matter connectivity patterns may be used to predict Alzheimer’s disease;however, detailed information on specific connectivity patterns is needed. All study data were obtained from the Alzheimer’s Disease Neuroimaging Initiative Library of the Image and Data Archive Database. 展开更多
关键词 Alzheimer's disease blood oxygen level-dependent signal correlation coefficient FUNCTIONAL connectivity pattern FUNCTIONAL magnetic resonance imaging GRAY MATTER RESTING state white MATTER
在线阅读 下载PDF
Contribution of ghrelin to functional gastrointestinal disorders’pathogenesis 预览
3
作者 Tilemachos Koutouratsas Theodora Kalli +1 位作者 Georgios Karamanolis Maria Gazouli 《世界胃肠病学杂志:英文版》 SCIE CAS 2019年第5期539-551,共13页
Functional gastrointestinal disorders(FGID)are heterogeneous disorders with a variety of clinical manifestations,primarily defined by signs and symptoms rather than a definite underlying cause.Their pathophysiology re... Functional gastrointestinal disorders(FGID)are heterogeneous disorders with a variety of clinical manifestations,primarily defined by signs and symptoms rather than a definite underlying cause.Their pathophysiology remains obscure and,although it is expected to differ according to the specific FGID,disruptions in the brain-gut axis are now thought to be a common denominator in their pathogenesis.The hormone ghrelin is an important component of this axis,exerting a wide repertoire of physiological actions,including regulation of gastrointestinal motility and protection of mucosal tissue.Ghrelin’s gene shows genetic polymorphism,while its protein product undergoes complex regulation and metabolism in the human body.Numerous studies have studied ghrelin’s relation to the emergence of FGIDs,its potential value as an index of disease severity and as a predictive marker for symptom relief during attempted treatment.Despite the mixed results currently available in scientific literature,the plethora of statistically significant findings shows that disruptions in ghrelin genetics and expression are plausibly related to FGID pathogenesis.The aim of this paper is to review current literature studying these associations,in an effort to uncover certain patterns of alterations in both genetics and expression,which could delineate its true contribution to FGID emergence,either as a causative agent or as a pathogenetic intermediate. 展开更多
关键词 FUNCTIONAL GASTROINTESTINAL disorders FUNCTIONAL colonic diseases Irritable bowel SYNDROME Cyclic VOMITING SYNDROME Infantile COLIC GASTROINTESTINAL disease GHRELIN Genetics Epigenetic processes
在线阅读 免费下载
Resting-state network complexity and magnitude changes in neonates with severe hypoxic ischemic encephalopathy 预览
4
作者 Hong-Xin Li Min Yu +4 位作者 Ai-Bin Zheng Qin-Fen Zhang Guo-Wei Hua Wen-Juan Tu Li-Chi Zhang 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第4期642-648,共7页
Resting-state functional magnetic resonance imaging has revealed disrupted brain network connectivity in adults and teenagers with cerebral palsy.However,the specific brain networks implicated in neonatal cases remain... Resting-state functional magnetic resonance imaging has revealed disrupted brain network connectivity in adults and teenagers with cerebral palsy.However,the specific brain networks implicated in neonatal cases remain poorly understood.In this study,we recruited 14 termborn infants with mild hypoxic ischemic encephalopathy and 14 term-born infants with severe hypoxic ischemic encephalopathy from Changzhou Children’s Hospital,China.Resting-state functional magnetic resonance imaging data showed efficient small-world organization in whole-brain networks in both the mild and severe hypoxic ischemic encephalopathy groups.However,compared with the mild hypoxic ischemic encephalopathy group,the severe hypoxic ischemic encephalopathy group exhibited decreased local efficiency and a low clustering coefficient.The distribution of hub regions in the functional networks had fewer nodes in the severe hypoxic ischemic encephalopathy group compared with the mild hypoxic ischemic encephalopathy group.Moreover,nodal efficiency was reduced in the left rolandic operculum,left supramarginal gyrus,bilateral superior temporal gyrus,and right middle temporal gyrus.These results suggest that the topological structure of the resting state functional network in children with severe hypoxic ischemic encephalopathy is clearly distinct from that in children with mild hypoxic ischemic encephalopathy,and may be associated with impaired language,motion,and cognition.These data indicate that it may be possible to make early predictions regarding brain development in children with severe hypoxic ischemic encephalopathy,enabling early interventions targeting brain function.This study was approved by the Regional Ethics Review Boards of the Changzhou Children’s Hospital(approval No.2013-001)on January 31,2013.Informed consent was obtained from the family members of the children.The trial was registered with the Chinese Clinical Trial Registry(registration number:ChiCTR1800016409)and the protocol version is 1.0. 展开更多
关键词 nerve REGENERATION NEONATES hypoxic ischemic encephalopathy RESTING-STATE FUNCTIONAL magnetic resonance imaging BRAIN networks SMALL-WORLD organization BRAIN FUNCTIONAL connectivity local efficiency clustering coefficient neural REGENERATION
在线阅读 下载PDF
The development of brain functional connectivity networks revealed by resting-state functional magnetic resonance imaging 预览
5
作者 Chao-Lin Li Yan-Jun Deng +2 位作者 Yu-Hui He Hong-Chang Zhai Fu-Cang Jia 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第8期1419-1429,共11页
Previous studies on brain functional connectivity networks in children have mainly focused on changes in function in specific brain regions, as opposed to whole brain connectivity in healthy children. By analyzing the... Previous studies on brain functional connectivity networks in children have mainly focused on changes in function in specific brain regions, as opposed to whole brain connectivity in healthy children. By analyzing the independent components of activation and network connectivity between brain regions, we examined brain activity status and development trends in children aged 3 and 5 years. These data could provide a reference for brain function rehabilitation in children with illness or abnormal function. We acquired functional magnetic resonance images from 15 3-year-old children and 15 5-year-old children under natural sleep cond让ions. The participants were recruited from five kindergartens in the Nanshan District of Shenzhen City, China. The parents of the participants signed an informed consent form with the premise that they had been fully informed regarding the experimental protocol. We used masked independent component analysis and BrainNet Viewer software to explore the independent components of the brain and correlation connections between brain regions. We identified seven independent components in the two groups of children, including the executive control network, the dorsal attention network, the default mode network, the left frontoparietal network, the right frontoparietal network, the salience network, and the motor network. In the default mode network, the posterior cingulate cortex, medial frontal gyrus, and inferior parietal lobule were activated in both 3- and 5-year-old children, supporting the "three-brain region theory” of the default mode network. In the frontoparietal network, the frontal and parietal gyri were activated in the two groups of children, and functional connectivity was strengthened in 5-year-olds compared with 3-year-olds, although the nodes and network connections were not yet mature. The high-correlation network connections in the default mode networks and dorsal attention networks had been significantly strengthened in 5-year-olds vs. 3-year-olds. Further, the salience 展开更多
关键词 nerve REGENERATION FUNCTIONAL MRI BRAIN network FUNCTIONAL connectivity RESTING-STATE ICA BRAIN development children RESTING-STATE NETWORKS INFANT template standardized neural REGENERATION
在线阅读 下载PDF
[ONSO]AlCl配合物催化4-乙烯基环氧环己烷聚合制备聚醚及其功能化 预览
6
作者 许云鹏 贾涛 +2 位作者 黄杰 段中余 刘宾元 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2019年第8期22-29,共8页
通过溶剂挥发法得到[ONSO]型配体L的晶体,对其单晶结构进行了解析;制备该配体的金属Al配合物1,以1为催化剂,研究了单体与催化剂摩尔比、邻苯二甲酸酐(PA)加入量对4-乙烯基环氧环己烷(4-VCHO)聚合反应的影响。在[VCHO]∶[PA]∶[1]=250∶5... 通过溶剂挥发法得到[ONSO]型配体L的晶体,对其单晶结构进行了解析;制备该配体的金属Al配合物1,以1为催化剂,研究了单体与催化剂摩尔比、邻苯二甲酸酐(PA)加入量对4-乙烯基环氧环己烷(4-VCHO)聚合反应的影响。在[VCHO]∶[PA]∶[1]=250∶50∶1,90℃时本体聚合反应30min,收率达到49%,催化活性(TOF值)为245h-1,相对分子质量为22000,相对分子质量分布为2.1。对所得的聚乙烯基环氧环己烷(PVCHO)进行功能化修饰,依次将聚合物侧链双键转变为环氧基团、环状碳酸酯、羟基(-OH)、巯基(-SH)。PVCHO侧链的环氧化和环状碳酸酯化使得其玻璃化转变温度分别提高了58℃和84℃。 展开更多
关键词 [ONSO] 单晶结构 铝配合物 功能化 聚醚
在线阅读 下载PDF
聚偏氟乙烯树脂改性研究进展 预览
7
作者 叶翠翠 俞群力 +1 位作者 沈洁清 李勇进 《化工生产与技术》 CAS 2019年第1期18-25,I0003共9页
介绍了聚偏氟乙烯(PVDF)材料改性的主要方法及其改性材料的应用领域。从物理改性方法(热处理、涂覆和共混)和化学改性方法(光引发、等离子体诱导、辐照引发和臭氧活化)等方面出发,探讨了改性方法对PVDF材料性能的影响,叙述了改性PVDF树... 介绍了聚偏氟乙烯(PVDF)材料改性的主要方法及其改性材料的应用领域。从物理改性方法(热处理、涂覆和共混)和化学改性方法(光引发、等离子体诱导、辐照引发和臭氧活化)等方面出发,探讨了改性方法对PVDF材料性能的影响,叙述了改性PVDF树脂在介电材料、压电材料以及水处理等应用领域的发展。认为在PVDF改性研究的方面应该以提高改性材料性能的稳定性、提高单体接枝率为重点,进一步开发出性能优异的PVDF功能材料,以应对在压电材料、介电材料、过滤材料等领域实际应用过程中的需求。 展开更多
关键词 聚偏氟乙烯 改性 接枝 功能化
在线阅读 下载PDF
Up-regulation of a homeodomain-leucine zipper gene HD-1 contributes to trichome initiation and development in cotton 预览
8
作者 NIU Er-li CAI Cai-ping +3 位作者 BAO Jiang-hao WU Shuang ZHAO Liang GUO Wang-zhen 《农业科学学报:英文版》 SCIE CAS CSCD 2019年第2期361-371,共11页
Plant trichomes originate from epidermal cells.In this work,we demonstrated that a homeodomain-leucine zipper(HD-Zip)gene,GhA06G1283(Gh HD-1A),was related to the leaf trichome trait in allotetraploid cotton and could ... Plant trichomes originate from epidermal cells.In this work,we demonstrated that a homeodomain-leucine zipper(HD-Zip)gene,GhA06G1283(Gh HD-1A),was related to the leaf trichome trait in allotetraploid cotton and could be a candidate gene for the T1 locus.The ortholog of GhHD-1A in the hairless accession Gossypium barbadense cv.Hai7124 was interrupted by a long terminal repeat(LTR)retrotransposon,while GhHD-1A worked well in the hairy accession Gossypium hirsutum acc.T586.Sequence and phylogenetic analysis showed that GhHD-1A belonged to the HD-Zip IV gene family,which mainly regulated epidermis hair development in plants.Silencing of GhHD-1A and its homoeologs GhHD-1D in allotetraploid T586and Hai7124 could significantly reduce the density of leaf hairs and affect the expression levels of other genes related to leaf trichome formation.Further analysis found that GhHD-1A mainly regulated trichome initiation on the upper epidermal hairs of leaves in cotton,while the up-regulated expression of GhHD-1A in different organs/tissues also altered epidermal trichome development.This study not only helps to unravel the important roles of GhHD-1A in regulating trichome initiation in cotton,but also provides a reference for exploring the different forms of trichome development in plants. 展开更多
关键词 leaf TRICHOME map-based cloning a homeodomain-leucine ZIPPER GENE HD-1 virus-induced GENE silencing (VIGS) functional differentiation
在线阅读 下载PDF
Long-term monitoring revealed fish assemblage zonation in the Three Gorges Reservoir 预览
9
作者 LIN Pengcheng GAO Xin +2 位作者 LIU Fei LI Mingzheng LIU Huanzhang 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2019年第4期1258-1267,共10页
Reservoirs are important artificial ecosystems that modify the hydrological and ecological characteristics of a river. Knowledge of the basic characteristics of fish assemblages in reservoirs is a first step toward th... Reservoirs are important artificial ecosystems that modify the hydrological and ecological characteristics of a river. Knowledge of the basic characteristics of fish assemblages in reservoirs is a first step toward the development of effective conservation policies. We used the information collected over a 10-year period (2006-2015) to assess the structure of the fish assemblages in the Three Gorge Reservoir (TGR) in a river-dam gradient. Three fish zones were detected in TGR. Species richness was the highest in the upper zone and lowest in the lower zone. The riverine zones were dominated by rheophilic species Coreius guichenoti and Pelteobagrus vachelli. The transitional zones were dominated by Coreius heterodon and Rhinogobio cylindricus. The lacustrine zones were dominated by eurytopic species Hypophthalmichthys molitrix, Aristichthys nobilis, Hemiculter bleekeri and Cyprinus carpio. For the functional characteristics, fish assemblages in riverine and transitional zones were dominated by insectivorous species, equilibrium strategists and rheophilic species (e.g., Coreius heterodon and Coreius guichenoti). In lacustrine zones, the fish assemblage was dominated by habitat generalists common to lakes and reservoirs (e.g., Hemiculter bleekeri, Hypophthalmichthys molitrix, Aristichthys nobilis). Moreover, 18 exotic species (e.g., Protosalanx hyalocranius, Ictalurus punctatus, Megalobrama amblycephala, Tilapia) were collected in TGR, most of which only existed in the lacustrine zone. The results highlight the importance of freely flowing riverine reaches for conserving native fish in the upper Changjiang River and adaptive management strategies for fisheries in TGR. 展开更多
关键词 longitudinal GRADIENT IMPOUNDMENT functional GROUPS EXOTIC species dam effects
在线阅读 下载PDF
鼻内镜辅助下减张法功能性鼻整形手术疗效观察 预览
10
作者 张红佳 王丰 +4 位作者 周成勇 韩泽利 韩佳宏 沈瑶 张娇 《中国耳鼻咽喉颅底外科杂志》 CAS 2019年第2期121-125,共5页
目的"减张法"是保持鼻背软骨-鼻中隔软骨复合体完整性、通过解除张力而使其居中对称的方法。本文研究鼻内镜辅助下减张法功能性鼻整形手术的主观和客观疗效。方法对67例行鼻内镜辅助下减张法功能性鼻整形手术的鼻畸形患者临... 目的"减张法"是保持鼻背软骨-鼻中隔软骨复合体完整性、通过解除张力而使其居中对称的方法。本文研究鼻内镜辅助下减张法功能性鼻整形手术的主观和客观疗效。方法对67例行鼻内镜辅助下减张法功能性鼻整形手术的鼻畸形患者临床资料进行回顾性总结分析。美学效果用电子测量尺测量和患者视觉模拟评分法。鼻阻塞改善程度用鼻阻力计测量和鼻阻塞症状评分法评估。结果 34例I型鼻畸形患者鼻畸形角度电子测量值术后(2.24±1.68)度与术前(11.94±3.17)度比较,差异具有统计学意义(P<0.001)。33例C型鼻畸形患者鼻畸形角度电子测量值术后(177.20±5.80)度与术前(158.34±9.96)度比较,差异具有统计学意义(P<0.001)。患者主观满意度很好53例(79.1%),好13例(19.4%),一般1例(1.5%)。术后鼻阻塞较术前明显改善,差异具有统计学意义(α=0.95,P<0.001)。术后随访期间所有患者未见并发症。结论鼻内镜下减张法功能性鼻整形手术有效、微创,适用于各种鼻畸形的治疗。 展开更多
关键词 鼻整形 鼻中隔偏曲 鼻内镜 鼻阻塞 鼻畸形 减张法 功能性
在线阅读 免费下载
Electrical, Thermal, and Mechanical Properties of Cu/Ti3AlC2 Functional Gradient Materials Prepared by Low-temperature Spark Plasma Sintering
11
作者 陈艳林 PENG Hang +3 位作者 LOU Lang HUANG Kang YAN Ming 吴崇刚 《武汉理工大学学报:材料科学英文版》 SCIE EI CAS 2019年第4期876-882,共7页
Cu/Ti3AlC2 composite and functional-gradient materials with excellent electrical conductivity and thermal conductivity as well as good flexural properties were prepared by low-temperature spark plasma sintering of Cu ... Cu/Ti3AlC2 composite and functional-gradient materials with excellent electrical conductivity and thermal conductivity as well as good flexural properties were prepared by low-temperature spark plasma sintering of Cu and Ti3AlC2 powder mixtures. The phase compositions of the materials were analyzed by X-ray diffraction, and their microstructure was characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. Further, the electrical conductivity, thermal conductivity, and flexural properties of the materials were tested. Results show that, for the composite materials, the resistivity rises from 0.75 × 10^-7 Ω·m only to 1.32 × 10^-7 Ω·m and the thermal diffusivity reduces from 82.5 mm^2/s simply to 39.8 mm^2/s, while the flexural strength improves from 412.9 MPa to 471.3 MPa, as the content of Ti3AlC2 is increased from 5 wt%to 25 wt%. Additionally, the functional-gradient materials sintered without interface between the layers exhibit good designability, and their overall electrical conductivity, thermal conductivity, and flexural strength are all higher than those of the corresponding uniform composite material. 展开更多
关键词 Cu/Ti3AlC2 FUNCTIONAL gradient material ELECTRICAL CONDUCTIVITY THERMAL CONDUCTIVITY
Open anterior glenohumeral dislocation with associated supraspinatus avulsion: A case report 预览
12
作者 Cosmin Ioan Faur Bogdan Anglitoiu Ana-Maria Ungureanu 《世界临床病例杂志》 2019年第7期849-854,共6页
BACKGROUND Open dislocation of the glenohumeral joint is a very rare complication with only six cases described in the literature. Most cases resulted in severe complications like avascular necrosis of the humeral hea... BACKGROUND Open dislocation of the glenohumeral joint is a very rare complication with only six cases described in the literature. Most cases resulted in severe complications like avascular necrosis of the humeral head or septic arthritis with poor functional results. The “mandatory” treatment of choice is surgery, with accurate debridement and reconstruction of the damaged soft tissues. However, the results in these cases do not approach those seen in classical dislocations. CASE SUMMARY This case report is the first description of an anterior open glenohumeral dislocation without associated fractures, but with complete avulsion of the soft tissue envelope of the proximal humerus. Surgical treatment consisted of copious lavage with saline solution, meticulous debridement of the nonviable soft tissues, reduction of the dislocated humeral head and reconstruction of the soft tissue envelope of the humeral head. The selected surgical approach was an inferior extension of the wound at the level of the delto-pectoral groove, as the best choice to be able to perform an adequate debridement and capsulo-tendinous reinsertion. At 6 mo there were no clinical signs of instability of the glenohumeral joint, the functionality of the joint was restricted to 90o of anterior elevation, internal rotation to L2, with severe limitation of abduction (60o) and external rotation (0o) but without residual pain, with an Oxford shoulder Score of 28. CONCLUSION Thorough reconstruction of the soft tissues surrounding the shoulder joint and an early rehabilitation program are key points to a good functional result. 展开更多
关键词 OPEN shoulder DISLOCATION Case report Functional impairment Surgical treatment AVASCULAR necrosis
在线阅读 免费下载
Brain networks modeling for studying the mechanism underlying the development of Alzheimer’s disease 预览
13
作者 Shuai-Zong Si Xiao Liu +2 位作者 Jin-Fa Wang Bin Wang Hai Zhao 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第10期1805-1813,共9页
Alzheimer’s disease is a primary age-related neurodegenerative disorder that can result in impaired cognitive and memory functions.Although connections between changes in brain networks of Alzheimer’s disease patien... Alzheimer’s disease is a primary age-related neurodegenerative disorder that can result in impaired cognitive and memory functions.Although connections between changes in brain networks of Alzheimer’s disease patients have been established,the mechanisms that drive these alterations remain incompletely understood.This study,which was conducted in 2018 at Northeastern University in China,included data from 97 participants of the Alzheimer’s Disease Neuroimaging Initiative(ADNI)dataset covering genetics,imaging,and clinical data.All participants were divided into two groups:normal control(n=52;20 males and 32 females;mean age 73.90±4.72 years)and Alzheimer’s disease(n=45,23 males and 22 females;mean age 74.85±5.66).To uncover the wiring mechanisms that shaped changes in the topology of human brain networks of Alzheimer’s disease patients,we proposed a local naive Bayes brain network model based on graph theory.Our results showed that the proposed model provided an excellent fit to observe networks in all properties examined,including clustering coefficient,modularity,characteristic path length,network efficiency,betweenness,and degree distribution compared with empirical methods.This proposed model simulated the wiring changes in human brain networks between controls and Alzheimer’s disease patients.Our results demonstrate its utility in understanding relationships between brain tissue structure and cognitive or behavioral functions.The ADNI was performed in accordance with the Good Clinical Practice guidelines,US 21 CFR Part 50-Protection of Human Subjects,and Part 56-Institutional Review Boards(IRBs)/Research Good Clinical Practice guidelines Institutional Review Boards(IRBs)/Research Ethics Boards(REBs). 展开更多
关键词 nerve REGENERATION Alzheimer's disease graph theory functional magnetic resonance imaging network model link prediction NAIVE Bayes topological structures ANATOMICAL distance global EFFICIENCY local EFFICIENCY neural REGENERATION
在线阅读 下载PDF
RESTplus: an improved toolkit for resting-state functional magnetic resonance imaging data processing
14
作者 Xi-Ze Jia Jue Wang +6 位作者 Hai-Yang Sun Han Zhang Wei Liao Ze Wang Chao-Gan Yan Xiao-Wei Song Yu-Feng Zang 《科学通报:英文版》 SCIE EI CSCD 2019年第14期953-954,共2页
Resting-state functional magnetic resonance imaging (RS-fMRI)[1,2] provides relatively high spatial and temporal resolution for mapping spontaneous brain activity non-invasively. It has been widely used in cognitive n... Resting-state functional magnetic resonance imaging (RS-fMRI)[1,2] provides relatively high spatial and temporal resolution for mapping spontaneous brain activity non-invasively. It has been widely used in cognitive neuroscience and clinical studies. A number of comprehensive software packages have been developed for RS-fMRI data analysis, among which a MATLAB package named REST (RESing-state fMRI data analysis Toolkit, released in October 2008 at http://www.restfmri.net)[3] is the earliest one dedicated to RS-fMRI analysis. REST focuses on RS-fMRI postprocessing metrics. 展开更多
关键词 RESTING-STATE functional magnetic RESONANCE IMAGING (RS-fMRI) REST MATLAB
Constant Volume Spray Auto-ignition Study of Alkanes 预览
15
作者 Wang Jun Yang He +2 位作者 Song Haiqing Tian Huayu Wang Pengfei 《中国炼油与石油化工:英文版》 SCIE CAS 2019年第1期71-79,共9页
Spray auto-ignition experiments were carried out in a constant volume combustion chamber for some pure alkanes(n-paraffins with different chain length, cyclohexane, n-butyl cyclohexane, and isooctane) and blends of n-... Spray auto-ignition experiments were carried out in a constant volume combustion chamber for some pure alkanes(n-paraffins with different chain length, cyclohexane, n-butyl cyclohexane, and isooctane) and blends of n-decane with Standard Blended Fuel(isooctane/n-heptane) and product gasoline. Test results showed that the reaction activity of n-paraffins was relatively high. Meanwhile, the auto-ignition characteristics differed significantly with the molecular structures of alkanes. Adding different volume fractions of n-decane to Standard Blended Fuel and product gasoline could improve the fuel reaction activity at varying degree. Finally, functional groups effects were used to simulate the relationship between the molecular topology and the auto-ignition quality. 展开更多
关键词 SPRAY AUTO-IGNITION reaction activity FUNCTIONAL GROUP ALKANE
在线阅读 下载PDF
Resilient PNT Concept Frame 预览
16
作者 Yuanxi YANG 《测绘学报(英文版)》 2019年第3期1-7,共7页
The concept of resilient positioning, navigation and timing (PNT) is described. The definition of resilient PNT is given, the relationship between integrated (or comprehensive) PNT and resilient PNT is analyzed, and i... The concept of resilient positioning, navigation and timing (PNT) is described. The definition of resilient PNT is given, the relationship between integrated (or comprehensive) PNT and resilient PNT is analyzed, and it is pointed out that the integrated PNT is the foundation of resilient PNT. Resilient PNT should be divided into resilient sensor integration, resilient functional model and resilient stochastic model. The strategy and principles of resilient integration of sensors are discussed. The resilient integration of sensors should be designed following the optimal, available, compatible and interoperable principles. The concepts of resilient functional model and possible modification strategies of the different functional models are also described. Several possible optimal routes for resilient stochastic model improvements are also set forth. It is pointed out that the optimal improvements of stochastic models for multi PNT sources should follow the same variance scale. At last, the resilient PNT data fusion for state parameters are given based on the resilient functional and stochastic models. 展开更多
关键词 resilient positioning navigation and TIMING (PNT) integrated PNT micro PNT resilient functional MODEL resilient stochastic MODEL
在线阅读 免费下载
Surface adsorption and diffusion of N on γ-Fe-Al (111) using first principles calculations
17
作者 Wen-shu Zhang Cai-li Zhang +4 位作者 Nan Dong Jian-guo Li Pei-de Han Zhu-xia Zhang Li-xia Ling 《钢铁研究学报:英文版》 SCIE EI CAS CSCD 2019年第8期882-887,共6页
The adsorption and diffusion of N on γ-Fe-Al (111) surface have been investigated using the first principle calculations combined with density functional theory to explore the formation mechanism of AlN in the oxidat... The adsorption and diffusion of N on γ-Fe-Al (111) surface have been investigated using the first principle calculations combined with density functional theory to explore the formation mechanism of AlN in the oxidation process of austenitic stainless steel. The results indicate that the most preferential adsorption site of N on the surface of γ-Fe (111) is fcc-hollow site. In addition, the stable positions are located at fcc adsorption site on clean and Al-doped γ-Fe (111) surface adsorbed 4.76 at.% N. Compared with the pure Fe system,γ-Fe-Al (111) system reduces the energy difference of N from the surface to the bulk. The system is most stable for 9.09 at.% N adsorbed on the octahedral interstice of the 2nd and 3rd atom interlamination of γ-Fe-Al (111) surface. Thus, the doping of Al makes it easier to spread N on the surface of γ-Fe (111). The increase in N in the atmosphere also accelerates the diffusion. Moreover, according to the density of states analysis, the interaction between Al and N was enhanced when 9.09 at.% N was adsorbed on the surface of γ-Fe-Al (111). 展开更多
关键词 NITROGEN Surface ADSORPTION DIFFUSION AUSTENITIC STAINLESS steel Density FUNCTIONAL theory
The Application of Functional Equivalence in Translation Based on Artistic Devices 预览
18
作者 杜鑫淼 《校园英语》 2019年第17期251-252,共2页
Ancient Chinese poets embody their feelings and aspirations in stuff like flowers.When translate these things,a tr anslator should take flowers’connotation consideration and find equiv alent ones that carry almost th... Ancient Chinese poets embody their feelings and aspirations in stuff like flowers.When translate these things,a tr anslator should take flowers’connotation consideration and find equiv alent ones that carry almost the same meaning.In translation studies,functionalists propose that translation is a type of human action,an intentional,purposeful behavior that take place in a given situation,which coincide with the translators’purposes towards this text. 展开更多
关键词 PLANTS MEANINGS functional EQUIVALENCE ARTISTIC devices
在线阅读 下载PDF
Cerebral functional abnormalities in patients with nasopharyngeal carcinoma after radiotherapy:an observational magnetic resonance resting-state study
19
作者 Wen-Ting Ren Ye-Xiong Li +12 位作者 Kai Wang Li Gao Jun-Lin Yi Xiao-Dong Huang Jing-Wei Luo Run-Ye Wu Yong Yang Jian-Yang Wang Wen-Qing Wang Jing-Bo Wang Feng Ye Han Ouyang Jian-Rong Dai 《中华医学杂志:英文版》 SCIE CAS CSCD 2019年第13期1563-1571,共9页
Background:Nasopharyngeal carcinoma (NPC) is sensitive to radiotherapy (RT).However,neurocognitive complications such as memory loss and learning and attention deficits emerge in the survivors of NPC who received RT.I... Background:Nasopharyngeal carcinoma (NPC) is sensitive to radiotherapy (RT).However,neurocognitive complications such as memory loss and learning and attention deficits emerge in the survivors of NPC who received RT.It remains unclear how radiation affects patient brain function.This pilot study aimed at finding cerebral functional alterations in NPC patients who have received RT.Methods:From September 2014 to December 2016,42 individuals,including 22 NPC patients and 20 normal volunteer controls in National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital,Chinese Academy of Medical Sciences,and Peking Union Medical College,were recruited in this study.All patients received resting-state functional magnetic resonance imaging scans and neurocognitive tests 1 day before the initiation of RT (baseline) and 1 day after the completion of RT;the 20 normal controls were also subjected to the same scans and tests.The amplitude of the low-frequency fluctuations (ALFF) in blood oxygen level-dependent signals and functional connectivity (FC) were used to characterize cerebral functional changes.Independent t test,paired t test,and analysis of variances were used to obtain statistical significance across groups.Results:After RT,NPC patients showed significantly decreased ALFF values in the calcarine sulcus,lingual gyrus,cuneus,and superior occipital gyrus and showed significantly reduced FC mainly in the default mode network (P < 0.05,corrected by AlphaSim).Relative to the controls,ALFF was decreased in the lingual gyrus,calcarine sulcus,cingulate cortex,medial prefrontal gyrus (P < 0.05,corrected by AlphaSim),and FC reduction was found in multiple cerebellar-cerebral regions,including the cerebellum,parahippocampus,hippocampus,fusiform gyrus,inferior frontal gyrus,inferior occipital gyrus,precuneus,and cingulate cortex (P < 0.001,corrected by AlphaSim).Conclusions:Cerebral functional alterations occur immediately after RT.This study may provide an explanation for the cognitive deficits in the morph 展开更多
关键词 RADIOTHERAPY NASOPHARYNGEAL carcinoma MRI Functional
Growth behavior and electronic properties of Gen+1 and AsGen(n = 1–20) clusters: a DFT study 预览
20
作者 M.Benaida K.E.Aiadi +3 位作者 S.Mahtout S.Djaadi W.Rammal M.Harb 《半导体学报:英文版》 EI CAS CSCD 2019年第3期9-17,共9页
We present a systematic computational study based on the density functional theory(DFT) aiming to high light the possible effects of one As doping atom on the structural, energetic, and electronic properties of differ... We present a systematic computational study based on the density functional theory(DFT) aiming to high light the possible effects of one As doping atom on the structural, energetic, and electronic properties of different isomers of Gen+1 clusters with n = 1–20 atoms. By considering a large number of structures for each cluster size, the lowest-energy isomers are determined. The lowest-energy isomers reveal three-dimensional structures starting from n = 5. Their relative stability versus atomic size is examined based on the calculated binding energy, fragmentation energy, and second-order difference of energy. Doping Gen+1 clusters with one As atom does not improve their stability. The electronic properties as a function of the atomic size are also discussed from the calculated HOMO–LUMO energy gap, vertical ionization potential, vertical electron affinity, and chemical hardness. The obtained results are significantly affected by the inclusion of one As atom into a Gen cluster. 展开更多
关键词 DENSITY FUNCTIONAL theory As–Ge CLUSTERS structural PROPERTIES ELECTRONIC PROPERTIES
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部 意见反馈