河北省2010-2015年重症手足口病流行特征及时空聚集性分析

目的 了解河北省2010-2015年重症手足口病(HFMD)流行特点及时空聚集性.方法 收集河北省2010-2015年HFMD监测数据,描述重症HFMD流行病学特征,应用GeoDa l.8.10进行空间自相关分析,SaTScanTM9.4.2进行时空聚集性分析,ArcGIS 10.2软件绘制专题地图进行结果可视化展示.结果 河北省2010-2015年共报告重症HFMD病例3641例,平均重症率0.85/105,其中2010年重症率最高(2.49/105),疫情波动呈“大小年”现象,5-7月发病高峰,季节分布明显,总体呈下降趋势.专题地图及空间自相关分析显示,各县区HFMD重症率差异较大,地区聚集性明显(Moran’sI＞0,P＜0.05).局部自相关分析显示,高值聚集区随时间变化较大,主要分布在河北省的中部和南部的部分地区.时空扫描分析确证,河北省南部邢台地区(隆尧县为中心,方圆60.96公里,20个区县)为最大可能聚集区(RR=38.08,LLR=1267.00,P＜0.001);次级高发聚集区集中在省会石家庄西北部(14个县区,RR=12.35)、沧州(16个,RR=11.35)、廊坊(8个,RR=44.04)和承德(17个,RR=10.32)等地区,其发病风险RR均在10以上,聚集时间主要集中在2010-2012年5-8月.2013-2015年重症数下降明显,唐山、邯郸、张家口和保定的大部分地区为低发聚集区(RR＜1).另对2207例实验室确诊病例病原构成分析显示,河北省重症HFMD病例仍以EV71(79.70％)感染为主.结论 河北省2010-2015年重症HFMD报告发病率存在时空聚集性,聚集地区主要集中在河北省的中南部地区,但总体疫情呈现波动下降趋势.     

Clonal clustering and colonization factors among thermolabile and porcine thermostable enterotoxin-producing Escherichia coli

A considerable proportion of enterotoxigenic Escherichia coli (ETEC) do not possess identifiable colonization factors (CFs). Genetic fingerprint analyses based on repetitive sequence-based polymerase chain reaction (rep-PCR) showed that 9 of 10 such CF-negative isolates which produced the thermolabile and the porcine thermostabile enterotoxin could be divided into three clusters. Following transformation with a plasmid harbouring the gene encoding CfaR, a positive regulator for several ETEC adhesins, three of the six strains in the first cluster expressed coli surface antigen 20 (CS20). No CFs were identified on the two transformed strains in the second cluster while the transformants of the two strains in the last cluster expressed CS12, the N-terminal amino acid sequence of which was deciphered. The study illustrates the potential of using genetic fingerprinting to group ETEC into clusters of strains with genes encoding different CFs and confirms the ability of CfaR to induce the expression of several different CFs.     

Targeting efficiency of RGD-modified nanocarriers with different ligand intervals in response to integrin αvβ3 clustering

Receptor change induced by ligand binding is a new issue to face in the field of targeted delivery. Receptor clustering, the main pattern of receptor changes, decreases the affinity between ligand and receptor due to the redistribution of receptor position. In an attempt to respond to such challenge, we designed and constructed three RGD-modified nanocarriers with different ligand intervals: stealth liposomes modified with the monomeric RGD (moRGD-LP), dimeric RGD (diRGD-LP) and a special dimeric RGD with a linker between two cyclic RGD motifs (P-diRGD-LP). The αvβ3-positive and -negative tumor cells (Melanoma B16 and MCF-7) were used as the cell models. As a result, P-diRGD-LP demonstrated strongest interaction with B16 cells in surface plasmon resonance study and highest cellular uptake in B16 cells in real-time confocal analysis. The enhanced endocytosis of P-diRGD-LP was found to be αvβ3-mediated and P-diRGD-LP increased the involvement of the clathrin-dependent pathway. Importantly, P-diRGD-LP demonstrated the best targeting effect in B16-tumor bearing mice in both in vivo and ex vivo near-infrared fluorescent images, about 2.4-fold that of moRGD-LP and 2.8-fold that of diRGD-LP at 3 h. Further, we validated integrin αvβ3 clustering on B16 cells via a single-molecule imaging by a total internal reflection fluorescence microscopy. Finally, the 3D models of αvβ3 clustering suggested a receptor interval within 41.916–65.779 Å, while the molecular computation revealed an RGD ligand interval of 20.944 Å, 42.753 Å and 78.196 Å for diRGD-LP, P-diRGD-LP and moRGD-LP, respectively, confirming the best matching between clustered αvβ3 and P-diRGD-LP. In conclusion, P-diRGD-LP could achieve higher targeting to αvβ3-positive tumor via the enhanced interaction based on the better ligand-receptor compatibility. The design of targeted nanocarriers against receptor clustering might provide new insight into the nanotechnology-based anticancer therapy.     

Non-Gaussian water diffusion in aging white matter

Age-associated white matter degeneration has been well documented and is likely an important mechanism contributing to cognitive decline in older adults. Recent work has explored a range of noninvasive neuroimaging procedures to differentially highlight alterations in the tissue microenvironment. Diffusional kurtosis imaging (DKI) is an extension of diffusion tensor imaging (DTI) that accounts for non-Gaussian water diffusion and can reflect alterations in the distribution and diffusion properties of tissue compartments. We used DKI to produce whole-brain voxel-based maps of mean, axial, and radial diffusional kurtoses, quantitative indices of the tissue microstructure's diffusional heterogeneity, in 111 participants ranging from the age of 33 to 91 years. As suggested from prior DTI studies, greater age was associated with alterations in white-matter tissue microstructure, which was reflected by a reduction in all 3 DKI metrics. Prominent effects were found in prefrontal and association white matter compared with relatively preserved primary motor and visual areas. Although DKI metrics co-varied with DTI metrics on a global level, DKI provided unique regional sensitivity to the effects of age not available with DTI. DKI metrics were additionally useful in combination with DTI metrics for the classification of regions according to their multivariate “diffusion footprint”, or pattern of relative age effect sizes. It is possible that the specific multivariate patterns of age-associated changes measured are representative of different types of microstructural pathology. These results suggest that DKI provides important complementary indices of brain microstructure for the study of brain aging and neurologic disease.     

静息态脑功能网络分析的假设驱动和数据驱动方法综述

基于功能磁共振成像的研究已发现在脑区之间存在低频波动一致的脑功能网络.脑功能网络有助于认识脑功能和诊断神经精神疾病,而脑功能网络分析方法在其中具有重要地位.本文首先综述了假设驱动和数据驱动进行脑功能网络分析的两类方法,接着对常用的基于感兴趣区、基于体素、基于独立成分分析、基于主成分分析和基于聚类方法的原理、优缺点做了详细介绍,并着重阐述了最近提出的组信息指导的独立成分分析方法,及基于半监督学习技术的感兴趣区选择方法,最后对改进方向进行了展望.     

A novel region-based level set method initialized with mean shift clustering for automated medical image segmentation

Appropriate initialization and stable evolution are desirable criteria to satisfy in level set methods. In this study, a novel region-based level set method utilizing both global and local image information complementarily is proposed. The global image information is extracted from mean shift clustering without any prior knowledge. Appropriate initial contours are obtained by regulating the clustering results. The local image information, as extracted by a data fitting energy, is employed to maintain a stable evolution of the zero level set curves. The advantages of the proposed method are as follows. First, the controlling parameters of the evolution can be easily estimated by the clustering results. Second, the automaticity of the model increases because of a reduction in computational cost and manual intervention. Experimental results confirm the efficiency and accuracy of the proposed method for medical image segmentation.     

一种度量细胞网络结构的方法

文题释义： 复杂网络：是指具有自组织、自相似、小世界、无标度中部分或全部特征的网络。小世界效应和无标度特性是复杂网络最显著的特点。小世界是指网络具有大的簇系数和较小的平均路径长度,无标度是指网络节点的连接度分布服从幂律分布。 细胞网络：在多细胞生物体中,单个细胞除了完成自身功能外,各个细胞间的通讯联络是必不可少的,如维持生物体的生长发育、各种生理活动的协调等。如果将每个细胞抽象为一个节点,每两个细胞间的通讯抽象为一条边,那么众多细胞及其之间的通讯将抽象成为一个巨大的细胞网络。 背景：在多细胞组成的生物体社会中,细胞之间的通讯必不可少。众多细胞之间相互通讯、相互联系,形成了一个复杂的细胞网络结构。对细胞网络结构相关属性值进行度量和评价,显得极其重要。 目的：基于复杂网络,提出了一种细胞网络结构的度量方法。 方法：结合文献研究及实际应用,搭建细胞网络结构的度量框架,分别从细胞节点的度、细胞网络的度分布、细胞网络的平均路径长度、细胞网络的簇系数等方面对细胞网络结构进行度量。以某小型实验为例,进行了实例验证。 结果与结论：细胞网络的度分布中,绝大部分细胞节点的度值比较小,只有较少量细胞节点的度值较高。细胞网络中细胞节点的度分布P(k)的幂律分布特点越是明显,则此细胞网络结构越是合理,细胞网络越正常;同时,许多细胞网络结构具有较小的平均路径长度。细胞网络的簇系数越大,表明该细胞网络具有较高的聚集特性。一般情况下,细胞网络结构越“紧密”,细胞网络结构的“集团化”特性越明显,细胞网络越正常。 ORCID: 0000-0002-2483-032X(张雨) 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

福建省人体重要寄生虫感染家庭聚集性分析

目的调查福建省人体重要寄生虫感染家庭聚集性的现状。方法按《全国人体重要寄生虫病现状调查实施细则》规定的方法,对福建省13个县（市、区）39个抽样点的调查结果,采用二项分布拟合原理对重要感染虫种进行家庭聚集性分析。结果共调查6219户,20195人,蛔虫、鞭虫、钩虫感染率分别为9.55%、11.48%、19.73%,其分布均存在显著的家庭聚集性（P均〈0.001）。结论福建省人体肠道蛔虫、鞭虫和钩虫的感染均有家庭聚集性,建议以家庭为主体加强健康教育力度和驱虫,以提高和巩固防治效果.。     

Connectivity‐based parcellation: Critique and implications

Regional specialization and functional integration are often viewed as two fundamental principles of human brain organization. They are closely intertwined because each functionally specialized brain region is probably characterized by a distinct set of long‐range connections. This notion has prompted the quickly developing family of connectivity‐based parcellation (CBP) methods in neuroimaging research. CBP assumes that there is a latent structure of parcels in a region of interest (ROI). First, connectivity strengths are computed to other parts of the brain for each voxel/vertex within the ROI. These features are then used to identify functionally distinct groups of ROI voxels/vertices. CBP enjoys increasing popularity for the in‐vivo mapping of regional specialization in the human brain. Due to the requirements of different applications and datasets, CBP has diverged into a heterogeneous family of methods. This broad overview critically discusses the current state as well as the commonalities and idiosyncrasies of the main CBP methods. We target frequent concerns faced by novices and veterans to provide a reference for the investigation and review of CBP studies. Hum Brain Mapp 36:4771–4792, 2015. © 2015 Wiley Periodicals, Inc.