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1.
The aorta, with ascending, arch, thoracic and abdominal segments, responds to the heartbeat, senses metabolites and distributes blood to all parts of the body. However, the heterogeneity across aortic segments and how metabolic pathologies change it are not known. Here, a total of 216 612 individual cells from the ascending aorta, aortic arch, and thoracic and abdominal segments of mouse aortas under normal conditions or with high blood glucose levels, high dietary salt, or high fat intake were profiled using single-cell RNA sequencing. We generated a compendium of 10 distinct cell types, mainly endothelial (EC), smooth muscle (SMC), stromal and immune cells. The distributions of the different cells and their intercommunication were influenced by the hemodynamic microenvironment across anatomical segments, and the spatial heterogeneity of ECs and SMCs may contribute to differential vascular dilation and constriction that were measured by wire myography. Importantly, the composition of aortic cells, their gene expression profiles and their regulatory intercellular networks broadly changed in response to high fat/salt/glucose conditions. Notably, the abdominal aorta showed the most dramatic changes in cellular composition, particularly involving ECs, fibroblasts and myeloid cells with cardiovascular risk factor-related regulons and gene expression networks. Our study elucidates the nature and range of aortic cell diversity, with implications for the treatment of metabolic pathologies.  相似文献   

2.
IntroductionEpithelial cells (ECs) are structures regularly observed during urine microscopy analysis. The correct identification of EC subtypes can be useful since renal tubular epithelial cells (RTECs) are clinically relevant. We investigate the urinary ECs report and the judgement of its clinical importance by Brazilian laboratories.Materials and methodsA survey with four questions was made available to participants of the Urinalysis External Quality Assessment Program (EQAP) from Controllab. Laboratories composed 3 groups: (1) differentiating ECs subtypes: “squamous”, “transitional” and “RTECs”; (2) differentiating ECs subtypes: “squamous” or “non-squamous” cells; (3) without ECs subtype identification. Participants did not necessarily answer to all questions and the answers were evaluated both within the same laboratory’s category and within different categories of laboratories.ResultsA total of 1336 (94%) laboratories answered the survey; Group 1, 119/140 (85%) reported that ECs differentiation is important to the physician and 62% want to be evaluated by EQAP, while in Group 3, 455/1110 (41%) reported it is useful to them, however only 25% want be evaluated by EQAP. Group 2 laboratories 37/51 (73%) reported that the information is important, but only 13/52 (25%) are interested in an EQAP with differentiation of the 3 ECs subtypes.ConclusionMost of the laboratories do not differentiate ECs in the three subtypes, despite the clinical importance of RTECs. Education of laboratory staff about the clinical significance of urinary particles should be considered a key priority.  相似文献   

3.
A multi-functional microfluidic platform was fabricated to demonstrate the feasibility of on-chip electroporation integrated with dielectrophoresis (DEP) and alternating-current-electro-osmosis (ACEO) assisted cell/particle manipulation. A spatial gradient of electroporation parameters was generated within a microchamber array and validated using normal human dermal fibroblast (NHDF) cells and red fluorescent protein-expressing human umbilical vein endothelial cells (RFP-HUVECs) with various fluorescent indicators. The edge of the bottom electrode, coinciding with the microchamber entrance, may act as an on-demand gate, functioning under either positive or negative DEP. In addition, at sufficiently low activation frequencies, ACEO vortices can complement the DEP to contribute to a rapid trapping/alignment of particles. As such, results clearly indicate that the microfluidic platform has the potential to achieve high-throughput screening for electroporation with spatial control and uniformity, assisted by DEP and ACEO manipulation/trapping of particles/cells into individual microchambers.  相似文献   

4.
陆康 《现代情报》2015,35(4):128-133
媒体平台伴随着互联网的发展,其主要应用是提供各种用户群体在互联网中实现自我展示的空间,例如微信、微博等。不同平台针对不同的用户群体。图书馆利用平台进行图书馆网络服务,可以根据兴趣爱好对读者进行分类,利用平台进行针对性的读者服务工作。本文介绍了各种平台特点与功能,以及平台运用、平台创新、平台展示等相关概念。建立平台应用流程模型同时提出平台效应概念,探讨出图书馆利用平台进行网络服务的方法与注意事项。  相似文献   

5.
知识元搜索引擎:CNKI知识搜索平台   总被引：5，自引：0，他引：5  
周秀会 《现代情报》2007,27(5):220-222
介绍了CNKI知识搜索平台的功能,重点阐述了它的特色,它从技术、资源方面实现了多种资源的整合、实现了实时的知识聚类、知识元搜索、提供多样化的搜索排序和知识元链接功能,大大优于现有的各种搜索引擎和检索平台。本文对CNKI知识搜索平台的功能进行了评价,认为CNKI知识搜索平台是基于对文献内容的搜索,弥补了搜索引擎及同类检索平台的不足,能够满足用户需求,代表了电子资源检索平台的发展方向。  相似文献   

6.
Studying the effects of pharmacological agents on human endothelium includes the routine use of cell monolayers cultivated in multi-well plates. This configuration fails to recapitulate the complex architecture of vascular networks in vivo and does not capture the relationship between shear stress (i.e. flow) experienced by the cells and dose of the applied pharmacological agents. Microfluidic platforms have been applied extensively to create vascular systems in vitro; however, they rely on bulky external hardware to operate, which hinders the wide application of microfluidic chips by non-microfluidic experts. Here, we have developed a standalone perfusion platform where multiple devices were perfused at a time with a single miniaturized peristaltic pump. Using the platform, multiple micro-vessel networks, that contained three levels of branching structures, were created by culturing endothelial cells within circular micro-channel networks mimicking the geometrical configuration of natural blood vessels. To demonstrate the feasibility of our platform for drug testing and validation assays, a drug induced nitric oxide assay was performed on the engineered micro-vessel network using a panel of vaso-active drugs (acetylcholine, phenylephrine, atorvastatin, and sildenafil), showing both flow and drug dose dependent responses. The interactive effects between flow and drug dose for sildenafil could not be captured by a simple straight rectangular channel coated with endothelial cells, but it was captured in a more physiological branching circular network. A monocyte adhesion assay was also demonstrated with and without stimulation by an inflammatory cytokine, tumor necrosis factor-α.  相似文献   

7.
森林生态系统结构调控与功能优化是森林生态与管理的核心研究主题。然而,受技术与理论限制,复杂地形下森林三维精细结构监测能力不足、功能估测精度不高;森林生态系统结构的复杂性和人类社会对其服务功能的迫切需求对上述研究主题提出前所未有的挑战。在中国科学院野外站网络重点科技基础设施建设项目的支持下,中国科学院清原森林生态系统观测研究站于2019年在典型独立小流域内建成了观测塔群(3座观测塔)、水文站网、长期固定样地群,辅以综合数据中心;打造以激光雷达为主要森林结构监测、以涡动通量系统和水文站网为主要功能监测手段的"温带次生林生态系统塔群监测研究平台"(以下简称"科尔塔群")。科尔塔群集成了观测塔群-水文站网-长期固定样地群,构成以遥感技术-涡度相关法-测树学法-森林信息学法为主要手段的协同、跨学科观测体系,具有多方法、多尺度、多要素的核心特征,可开展多类相关研究以满足国家需求、探索国际前沿。基于上述优势,科尔塔群可准确获取森林三维结构,以全息新视角探索森林生态学规律,发展复杂地形下森林生态系统碳-氮-水和其他痕量气体通量观测新理论与方法,研究全球变化背景下森林生态系统碳-氮-水等循环过程与响应,阐明森林水文过程及调控机制,为森林结构调控与功能优化提供基础数据和理论支持,使森林为人类社会提供广泛且可持续的生态服务。  相似文献   

8.
Diffusion of autocrine and paracrine signaling molecules allows cells to communicate in the absence of physical contact. This chemical-based, long-range communication serves crucial roles in tissue function, activation of the immune system, and other physiological functions. Despite its importance, few in vitro methods to study cell-cell signaling through paracrine factors are available today. Here, we report the design and validation of a microfluidic platform that enables (i) soluble molecule-cell and/or (ii) cell-cell paracrine signaling. In the microfluidic platform, multiple cell populations can be introduced into parallel channels. The channels are separated by arrays of posts allowing diffusion of paracrine molecules between cell populations. A computational analysis was performed to aid design of the microfluidic platform. Specifically, it revealed that channel spacing affects both spatial and temporal distribution of signaling molecules, while the initial concentration of the signaling molecule mainly affects the concentration of the signaling molecules excreted by the cells. To validate the microfluidic platform, a model system composed of the signaling molecule lipopolysaccharide, mouse macrophages, and engineered human embryonic kidney cells was introduced into the platform. Upon diffusion from the first channel to the second channel, lipopolysaccharide activates the macrophages which begin to produce TNF-α. The TNF-α diffuses from the second channel to the third channel to stimulate the kidney cells, which express green fluorescent protein (GFP) in response. By increasing the initial lipopolysaccharide concentration an increase in fluorescent response was recorded, demonstrating the ability to quantify intercellular communication between 3D cellular constructs using the microfluidic platform reported here. Overall, these studies provide a detailed analysis on how concentration of the initial signaling molecules, spatiotemporal dynamics, and inter-channel spacing affect intercellular communication.  相似文献   

9.
Atherosclerotic lesions occur non-randomly at vascular niches in bends and bifurcations where fluid flow can be characterized as "disturbed" (low shear stress with both forward and retrograde flow). Endothelial cells (ECs) at these locations experience significantly lower average shear stress without change in the levels of pressure or strain, which affects the local balance in mechanical stresses. Common in vitro models of atherosclerosis focus primarily on shear stress without accounting for pressure and strain loading. To overcome this limitation, we used our microfluidic endothelial cell culture model (ECCM) to achieve accurate replication of pressure, strain, and shear stress waveforms associated with both normal flow seen in straight sections of arteries and disturbed flow seen in the abdominal aorta in the infrarenal segment at the wall distal to the inferior mesenteric artery (IMA), which is associated with high incidence of atherosclerotic lesion formation. Human aortic endothelial cells (HAECs) were cultured within the ECCM under both normal and disturbed flow and evaluated for cell shape, cytoskeletal alignment, endothelial barrier function, and inflammation using immunofluorescence microscopy and flow cytometry. Results clearly demonstrate quantifiable differences between cells cultured under disturbed flow conditions, which are cuboidal with short and randomly oriented actin microfilaments and show intermittent expression of β-Catenin and cells cultured under normal flow. However, in the absence of pro-inflammatory stimulation, the levels of expression of activation markers: intra cellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), platelet endothelial cell adhesion molecule-1 (PECAM-1), and vascular endothelial cell growth factor - receptor 2 (VEGF-R2) known to be involved in the initiation of plaque formation were only slightly higher in HAECs cultured under disturbed flow in comparison to cells cultured under normal flow.  相似文献   

10.
[目的/意义]基于情景分析理论,检验高校科研数据平台功能的可用性,促使科研数据发挥更大价值,实现科研数据全方位管理,推动开放科学和开放数据的发展。[方法/过程]针对科研过程的阶段特征,采用情景分析法构建了科研过程的4个情景,重点针对实施阶段的情景,以复旦大学社会科学数据平台为例开展了眼动追踪实验研究。[结果/结论]初步确定了高校科研数据平台的四大功能定位:用于选题立项的功能,用于科研准备的功能,用于科研实施的功能和用于成果管理的功能。最后对新一代高校科研数据平台功能重新定位与优化,能够实现数据一站式管理、数据开放、数据共享以及数据再利用功能。  相似文献   

11.
The blood-brain barrier (BBB) is a critical structure that serves as the gatekeeper between the central nervous system and the rest of the body. It is the responsibility of the BBB to facilitate the entry of required nutrients into the brain and to exclude potentially harmful compounds; however, this complex structure has remained difficult to model faithfully in vitro. Accurate in vitro models are necessary for understanding how the BBB forms and functions, as well as for evaluating drug and toxin penetration across the barrier. Many previous models have failed to support all the cell types involved in the BBB formation and/or lacked the flow-created shear forces needed for mature tight junction formation. To address these issues and to help establish a more faithful in vitro model of the BBB, we have designed and fabricated a microfluidic device that is comprised of both a vascular chamber and a brain chamber separated by a porous membrane. This design allows for cell-to-cell communication between endothelial cells, astrocytes, and pericytes and independent perfusion of both compartments separated by the membrane. This NeuroVascular Unit (NVU) represents approximately one-millionth of the human brain, and hence, has sufficient cell mass to support a breadth of analytical measurements. The NVU has been validated with both fluorescein isothiocyanate (FITC)-dextran diffusion and transendothelial electrical resistance. The NVU has enabled in vitro modeling of the BBB using all human cell types and sampling effluent from both sides of the barrier.  相似文献   

12.
王福  高化  刘俊华  李哲  王科唯  韩丽萍 《情报科学》2021,39(11):150-156
【 目的/意义】移动音频有声阅读平台场景化服务离不开对其影响的各类因素及其相互作用关系的挖掘。在 此基础上,借助各类影响因素之间的交互作用,动态地调节各类影响因素的配置关系和配置方式,形成移动音频有 声阅读平台的场景化功效。【方法/过程】为此,将服务三要素以及场景要素、情境要素和信息期望纳入移动音频有 声阅读平台服务的研究视野,综合运用集成和适配的方法,构建了移动音频有声阅读平台的服务机理模型。【结果/ 结论】以喜马拉雅移动音频有声阅读平台为例,对本文构建的移动音频有声阅读平台服务机理模型进行实证,结果 表明集成和适配是有声平台的服务方向;设计和规划了移动音频有声阅读平台服务路径,对移动音频有声阅读平 台服务予以启示。【创新/局限】研究方法局限于文献进行的案例研究,下一步将继续深入进行实证研究。  相似文献   

13.
The cell''s micro-environment plays an important role in various physiological and pathological phenomena. To better investigate in vivo cellular behaviors, researchers have expended great effort in building controlled in vitro biophysical and biochemical environments. Because a cell''s gaseous environment affects properties such as its division, metastasis, and differentiation, we developed a zero-flow based platform for studying mammalian cell chemotaxis behavior in different oxygen environments. This platform can construct a linear range of oxygen tensions within one chip (i.e., from 1.4% to 3.6% or 5.5% to 14.5%). To study cell chemotaxis behavior under varying oxygen environments, the chemical gradient direction is established perpendicularly to oxygen change within an observation area. Because the observation area is not subject to flow, shear force is of no concern. In addition, water flow around the cell chambers greatly reduces evaporation and makes long-term microscope imaging possible. In this study, we precisely measure the chemotaxis velocity of MCF-7 human breast cancer cells under different oxygen tension conditions towards CXCL12, which is a stromal cell-derived factor. We find that cell migration rates are not equivalent, even under two close oxygen tensions. We also observed that cells move faster towards high concentrations of chemoattractant when the oxygen tension is below 3% due to the increased expression of HIF-1 (hypoxia-inducible factor 1), which promotes a transition to the amoeboid rather than mesenchymal mode of movement. Our experiments demonstrate that this new microfluidic platform is useful for the quantitative study of mammalian cell chemotaxis under different oxygen conditions in the absence of shear force. We also shed light on the study of chemotaxis under other gaseous environments.  相似文献   

14.
基于J2EE的网络教学平台的设计与实现   总被引：2，自引：1，他引：1  
从江西科技师范学院教学与计算机科学学院教学工作的实际情况出发.以及对广大师生的需求状况深入调研.提出基于Web的网络教学平台学习方式,实现了教师网上课程制作、网上批改作业、网上答疑、网上讨论、在线考试等功能.为学院创建一个统一的、标准化的网络教学空间.  相似文献   

15.
陈美 《现代情报》2019,39(3):69-76
[目的/意义]本研究针对我国地方政府数据开放平台面临的挑战，设计并构建基于CKAN的政府数据开放平台，为我国政府数据开放平台的建设和改进提供参考。[方法/过程]在对CKAN的应用及特征进行概述的基础上，分析CKAN具有的核心功能，探讨CKAN的元数据管理以及关联数据集的API发布，最后给出平台安装的步骤和策略。[结果/结论]充分发挥CKAN平台的核心功能、元数据管理以及关联数据集的API发布等方面的优势，结合Drupal等开源内容管理框架来构建政府数据开放平台才是最优选择。  相似文献   

16.
上皮细胞在机体内分布广泛,介导着包括呼吸、消化、生殖、听觉和免疫防御在内的一系列重要生理功能。上皮细胞功能紊乱将会导致广泛的病例改变和疾病,例如囊性纤维化病。"上皮细胞生物学研究中心"成立10年来,致力于上皮细胞生物学相关的研究,并通过多学科交叉性的合作取得了一定的成果。本文总结了研究中心以上皮细胞作为多学科交叉的切入点的研究进展,并探讨上皮细胞生物学对机体功能与疾病研究的重要性。  相似文献   

17.
Fluid shear stress (FSS) plays a critical role in regulating endothelium function and maintaining vascular homeostasis. Current microfluidic devices for studying FSS effects on cells either separate high shear stress zone and low shear stress zone into different culturing chambers, or arranging the zones serially along the flow direction, which complicates subsequent data interpretation. In this paper, we report a diamond shaped microfluidic shear device where the high shear stress zone and the low shear stress zone are arranged in parallel within one culturing chamber. Since the zones with different shear stress magnitudes are aligned normal to the flow direction, the cells in one stress group are not substantially affected by the flow-induced cytokine/chemokine releases by cells in the other group. Cell loading experiments using human umbilical vein endothelial cells show that the device is able to reveal stress magnitude-dependent and loading duration-dependent cell responses. The co-existence of shear stress zones with varied magnitudes within the same culturing chamber not only ensures that all the cells are subject to the identical culturing conditions, but also allows the resemblance of the differential shear stress pattern in natural arterial conditions. The device is expected to provide a new solution for studying the effects of heterogeneous hemodynamic patterns in the onset and progression of various vascular diseases.  相似文献   

18.
Extravasation of circulating cells is an essential process that governs tissue inflammation and the body''s response to pathogenic infection. To initiate anti-inflammatory and phagocytic functions within tissues, immune cells must cross the vascular endothelial barrier from the vessel lumen to the subluminal extracellular matrix. In this work, we present a microfluidic approach that enables the recreation of a three-dimensional, perfused endothelial vessel formed by human endothelial cells embedded within a collagen-rich matrix. Monocytes are introduced into the vessel perfusate, and we investigate the role of luminal flow and collagen concentration on extravasation. In vessels conditioned with the flow, increased monocyte adhesion to the vascular wall was observed, though fewer monocytes extravasated to the collagen hydrogel. Our results suggest that the lower rates of extravasation are due to the increased vessel integrity and reduced permeability of the endothelial monolayer. We further demonstrate that vascular permeability is a function of collagen hydrogel mass concentration, with increased collagen concentrations leading to elevated vascular permeability and increased extravasation. Collectively, our results demonstrate that extravasation of monocytes is highly regulated by the structural integrity of the endothelial monolayer. The microfluidic approach developed here allows for the dissection of the relative contributions of these cues to further understand the key governing processes that regulate circulating cell extravasation and inflammation.  相似文献   

19.
随着数字经济的不断渗透与数字平台的大量涌现,平台模式成为经济发展的重要引擎。虽然现有平台采用了相似的发展策略,但是不同平台的市场绩效存在较大差异,究其原因,平台层特征之一,即平台数字化功能在其中扮演了至关重要的作用。为了深入探究平台数字化功能如何影响平台策略与平台市场绩效之间的关系,本研究基于277份问卷调查数据进行了实证检验。结果发现:(1)平台规模策略、平台排他策略与平台市场绩效之间的关系均受到平台数字化功能的影响;(2)平台规模策略在社群支持功能的影响下,对平台市场绩效的影响更大;(3)平台排他策略在数据赋能功能的影响下,对平台市场绩效的影响更大。本研究从参与者层面和平台层面共同剖析了不同平台市场绩效差异的核心动因,并量化了数字化功能对平台绩效提升的作用效果,贡献于平台绩效管理与数字化功能的相关研究领域。  相似文献   

20.
Spheroid culture is a preferable cell culture approach for some cell types, including hepatocytes, as this type of culture often allows maintenance of organ-specific functions. In this study, we describe a spheroid microarray chip (SM chip) that allows stable immobilization of hepatocyte spheroids in microwells and that can be used to evaluate drug metabolism with high efficiency. The SM chip consists of 300-μm-diameter cylindrical wells with chemically modified bottom faces that form a 100-μm-diameter cell adhesion region surrounded by a nonadhesion region. Primary hepatocytes seeded onto this chip spontaneously formed spheroids of uniform diameter on the cell adhesion region in each microwell and these could be used for cytochrome P-450 fluorescence assays. A row of microwells could also be connected to a microchannel for simultaneous detection of different cytochrome P-450 enzyme activities on a single chip. The miniaturized features of this SM chip reduce the numbers of cells and the amounts of reagents required for assays. The detection of four cytochrome P-450 enzyme activities was demonstrated following induction by 3-methylcholantlene, with a sensitivity significantly higher than that in conventional monolayer culture. This microfabricated chip could therefore serve as a novel culture platform for various cell-based assays, including those used in drug screening, basic biological studies, and tissue engineering applications.  相似文献   

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