共查询到18条相似文献，搜索用时 53 毫秒
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传统心肌细胞电生理的研究,因其对细胞的穿刺损害作用,难以实现长时程测量,同时也难以实现对细胞群体的多位点同时测量.该研究采用微机械加工技术开展了基于细胞传感器(cell-based biosensor)的微电极阵列(microelectrode array, MEA)和光寻址电位传感器(light addressable potentiometric sensor, LAPS)等生物传感器技术,在传感器芯片表面培养了心肌细胞,并对其电生理特性进行了传感测量.该技术可对多个细胞同时进行长期、无损检测,在药物筛选、环境检测等生物医学领域具有良好的应用前景. 相似文献
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电子衡器经常需用多只传感器组合实现称重计量。本文通过理论分析,比较系统地讨论了多只传感器输出串联、并联、先串后并联和先并后串联等不同组合方式时的测量原理及其应用情况。 相似文献
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张存工 《仪表技术与传感器》1996,(9):24-27
电子衡器经常需要多传感器组合来实现称重测量。本文通过理论分析,比较系统地讨论了多传感器输出串联、并联、先串后并联和先并后串联等不同组合方式时的测量原理,以及不同的组合方式在实际中的应用情况。 相似文献
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多传感器信息融合技术及其应用 总被引：1，自引：0，他引：1
在阐述多传感器信息融合这一研究热点的融合过程和方法的基础上,介绍了D-S证据理论和Bayes方法,并探讨了信息融合技术在军事领域和民用领域方面的应用. 相似文献
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本文介绍了近年来十分活跃的研究领域——多传感器集成与信息融合的有关理论,给出了多传感器集成与信息融合的过程和方法.最后介绍了仿真实验样机. 相似文献
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基于USB接口通讯的多传感器数据采集系统以EZ-USB控制器为核心.由EZ-USB经控制电路实现对模数转换的控制,从而将被测系统中各传感器检测到的参数通过USB接口输入到计算机并显示出来.系统硬件主要采用以AN2131QC为核心的USB接口电路和以模数转换器AD7938为核心的USB设备功能单元电路.系统软件采用Keil C51语言编写芯片固件程序、采用VC++语言编写USB设备驱动程序和Win32应用程序. 相似文献
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基于LabVIEW的发动机多传感器信号采集系统 总被引：1，自引：0，他引：1
基于LabVIEW的发动机多传感器信号采集系统是运用虚拟仪器技术、多传感器信息融合技术,把信号调理、数据采集、信息显示、数据回放及存储集成在一起,完成对发动机多项数据的同步采集、显示、回放、存储。 相似文献
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The involvement of neural components in plasma extravasation and blood flow in the dental pulp has been established by pharmacological and physiological studies. We review here the segmental constitution of pulp vessels and the possible involvement of neural components in both the contractility and permeability of the pulp vessels from a morphological viewpoint. Six vascular segments can be identified based on the morphology of peri-endothelial cells, such as smooth muscle cells and pericytes. These are: muscular arterioles, terminal arterioles, precapillary arterioles, capillaries, postcapillary venules, and collecting or muscular venules. The perivascular nerve forms a mesh with numerous terminal varicosities, some of which attach directly to arteriolar smooth muscle cells. This mesh can be seen by scanning electron microscopy, and indicates the important role of neural components in regulating the pulpal circulation. After administering norepinephrine (0.2 mg/kg/dog), the surface texture of the smooth muscle cells of pulp arterioles reveals marked irregularities, which are correlated with arteriolar contraction. The pericytes in larger postcapillary venules (diameter 20 microm or larger) also show irregularities, whereas no changes are seen in the pericytes of either smaller postcapillary venules or capillaries. The intercellular spaces of pericytes in the postcapillary venules are wide enough for leukocytes to pass through, and the occasional extravasation of leukocytes through venule walls can be seen under electron microscopy. The microvessels of healthy human dental pulp react weakly to selectins, indicating that apparently healthy dental pulp may be weakly inflamed. In rat dental pulp, CGRP-immunoreactive nerves and nerve terminals containing many granular vesicles supply the postcapillary venules more densely than the arterioles, which suggests the involvement of postcapillary venules in neurogenic inflammation in the dental pulp. 相似文献
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剪切力对动脉血管平滑肌细胞增殖分化的影响 总被引：2，自引：0，他引：2
目的：探讨剪切力作用下人脐动脉血管平滑肌细胞的增殖分化的变化。方法：利用改进的灌流及流动培养装置,通过蠕动泵提供稳定的剪切力,同时提供静态培养所需的其它条件,建立体外人脐动脉血管平滑肌流动培养模型。分别对体外培养的人脐动脉血管平滑肌细胞加载3,4,5,8,10dyn／cm^2的定长流剪切力24h,同时以静态培养的细胞为对照组。相差倒置显微镜观察玻片上细胞的数量并作细胞计数,α—actin免疫组化染色．结果：细胞记数显示,同对照组相比,七刀应力各组的增殖能力都有所下降,5dyn／cm^2切应力作用下,细胞增殖缓慢最为明显．α—actin免疫组化染色提示切应力各组的分化程度较对照组高。结论：初步研究表明,剪切力对人脐动脉血管平滑肌细胞的增殖有一定抑制作用,并且可能促进了细胞的分化。 相似文献
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Due to its low beam current and charge compensation mechanism He-Ion scanning microscopy is a very promising tool for imaging biological cells. However, to obtain relevant information, the method used for sample preparation is also critical. In this work, we have used a Carl Zeiss Orion Plus helium-ion microscope to study the effect of sample gold coating on the morphology of human colorectal adenocarcinoma Caco2 cells. The fixative glutaraldehyde was used and the selective gold coating of the samples was investigated. A comparative study with standard scanning electron microscopy is presented. 相似文献
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Norma Risler Claudia Castro Montserrat Cruzado Susana González Roberto Miatello 《Biocell》2003,27(2):189-196
Remodeling of large and small arteries contributes to the development and complications of hypertension. Artery structural changes in chronic sustained hypertension include vascular smooth muscle cells (VSMC) proliferation and extracellular matrix (ECM) modifications. Extracellular constituents such as proteoglycans (PGs), may modulate vascular stiffness and VSMC growth and differentiation. We examined the effect of growth factors on secreted and membrane-bound PGs synthesis by cultured aortic smooth muscle cells (SMC) from 12- to 14- week-old spontaneously hypertensive rats (SHR) and age-matched Wistar rats. After stimulation with platelet-derived growth factor (PDGF-BB), 10% fetal calf serum (FCS) or 0.1% FCS as control, PGs synthesis (dpm/ng DNA) was evaluated in the medium (M-ECM) and in the cell layer (PECM) by a double-isotopic label method using both [3H]-glucosamine and [35S]-sodium sulfate which are incorporated into all complex carbohydrates or only into sulfated dysaccharides, respectively. Data are presented as percent of the control (0.1% FCS). SHR VSMC displayed a significantly greater synthesis of MECM [3H]-PGs than Wistar rat cells, with both treatments, but no differences in M-ECM [35S] uptake were found in any case. In the P-ECM, both PDGF-BB and 10% FCS produced a greater effect on [3H]-PGs and sulfated PGs synthesis in VSMC from SHR. An important change seen in SHR cells was a significant decreased sulfation, assesed by [35S]/[ 3H] ratio, in basal and stimulation conditions. Present results indicate the existence of changes in PGS synthesis and modulation in VSMC from a conduit-artery of SHR and support the pathophysiological role proposed for matrix proteoglycans in the vascular wall changes associated to hypertension and related vascular diseases as atherosclerosis. 相似文献
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Apoptosis is a physiologic form of cell death present in many disease conditions. When the balance of mitosis versus apoptosis is altered, tumor-like growth or degeneration of tissues may ensue. This appears to occur in several diseases, including those of the cardiovascular system, where apoptosis plays a key role in atherosclerosis and restenosis following angioplasty. Since c-myc is upregulated in the pathogenesis of these diseases, we chose to study the sequential morphologic features of programmed cell death in vascular smooth muscle cells induced by c-myc and by the adenovirus early gene E1A. Morphology and timed events in apoptotic cell cultures were analyzed by scanning electron microscopy, transmission electron microscopy, and time-lapse videomicroscopy. We observed that both c-myc-and E1A-induced apoptosis (in serum-free medium) resulted in numerous, tightly packed clusters of apoptotic blebs, as well as in one or two asymmetrically larger blebs. Transmission electron microscopy analysis revealed the larger blebs contained mostly nuclear chromatin, whereas the many smaller fragments often had little or no chromatin. Time-lapse studies showed that apoptosis was induced at a slower rate in cells stably transfected with c-myc versus those stably transfected with E1A. The early changes of apoptosis, including cell shrinkage and intense blebbing, occurred in under 5 min in both cells. Slight alterations such as cell size and further rounding occurred up to 8 h following the initial changes of apoptosis. Rather than being a part of the apoptotic response, release from the culture floor almost entirely resulted from movement of the culture flask. These studies provide a framework of timed morphologic events for future mechanistic investigation into the key aspects of myc-and E1A-induced apoptosis in vascular smooth muscle. 相似文献
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Nitric oxide (NO) generation by inducible nitric oxide synthase (iNOS) in the vascular smooth muscle cells (VSMC), may play a role in blood vessel tone regulation. Lipopolysaccharide (LPS) induced iNOS activity and subsequent nitrite production by cultured aortic VSMC, from SHR with an established chronic blood pressure elevation (adult SHR) or during the period preceding the development of hypertension (young SHR) and from age-matched normotensive Wistar (W) rats were compared. Angiotensin II (Ang II) effect was also evaluated. Both basal LPS-induced iNOS activity and nitrite accumulation were significantly lower in young SHR VSMC compared to young W rat cells. In contrast, adult hypertensive and normotensive rat cells did not differ in NO generation. Besides, young SHR cells exhibited a significant smaller iNOS activity and nitrites than adult SHR cells. After 24h-incubation with Ang II, both variables were markedly reduced in all groups. The proportional reduction of iNOS activity and nitrites by Ang II was not different between hypertensive and normotensive rat cells, at any age. However, this Ang II inhibitory effect was greater in both adult SHR and W cells than in VSMC from young rats. In conclusion, a reduced LPS-induced iNOS activity and NO generation was observed in VSMC form spontaneously hypertensive rats before the raise of blood pressure, but not in adult hypertensive rat cells. Additionally, an inhibitory effect of angiotensin II on these variables is described. We can speculate that the impairment in vascular smooth muscle NO production precedes the development of hypertension in SHR and may play a pathophysiologic role in the early blood pressure elevation in genetically hypertensive rats. 相似文献
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LUCIANA MAZZEI MARÍA BELÉN RUIZ-ROSO NATALIA DE LAS HERAS SANDRA BALLESTEROS CAROLINA TORRESPALAZZOLO LEÓN FERDER ALEJANDRA BEATRIZ CAMARGO WALTER MANUCHA 《Biocell》2020,44(4):671-681
The ancestral cultures have described many therapeutic properties of garlic; therefore, it is of central interest toelucidate the molecular basis explaining this millenary empirical knowledge. Indeed, it has been demonstrated aneuroprotective effect of allicin–a phytochemical present in garlic- linked to oxidative-inflammatory modulation.Allicin improved neuronal injury by heat shock protein 70 (Hsp70) and inducible nitric oxide synthase (iNOS)regulation. Also, allicin exerts renal protection involving a possible angiotensin type 1 receptor (AT1) interaction. Inconnection, AT1 overexpression has been recognized as a central deleterious factor in many brain diseases. However,there are no studies that evaluate AT1-Hsp70-iNOS interaction as a mechanism linked to neuroinflammation. Thus,our central aim is to evaluate if the allicin protective effect is associated with an AT1-Hsp70-iNOS counterbalanceaxis. For this study, a murine microglial cell line (BV-2) was injured with lipopolysaccharides and treated or not withallicin. Then, it was evaluated cell viability, proinflammatory cytokine levels, cellular oxidative stress, iNOS, Hsp70,and AT1 protein expression (cellular and mitochondrial fractions), nitrite levels, and protein-protein interactions. Theresults demonstrated that allicin could prevent neuronal injury due to a reduction in oxidative stress andinflammatory status mediated by an AT1-Hsp70-iNOS counterbalance axis linked to direct protein-protein interaction. 相似文献
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Asthma is a chronic disorder of the airways characterized by variable airway narrowing, mucus hypersecretion, and infiltration of the airway wall with eosinophils. It is now believed that asthma is controlled by Th2 lymphocytes producing cytokines such as IL-4, IL-5, IL-9, and IL-13. Animal models of eosinophilic airway inflammation and airway hyperreactivity have been developed to study the contribution of cells or mediators in the pathogenesis of asthma. In this review, we discuss the role of antigen presenting cells, CD4(+) and CD8(+) T lymphocytes, B lymphocytes, NK cells, and mast cells in the induction and maintenance of eosinophilic airway inflammation, mucus hypersecretion, and airway hyperreactivity. 相似文献
