排序方式: 共有19条查询结果,搜索用时 15 毫秒
11.
肺微循环内血液流动的连续介质整体模型 总被引:2,自引:0,他引:2
本文提出一种一维连续介质整体模型和相应的方程组,将之应用于肺循环內的血液流动问题,得到了封闭形式的分析解。分析表明,本文所得的结果与冯元桢采用片流理论所得的结果完全一致。 相似文献
12.
The entire process of oxygen transport in microcirculation by developing a 3D porous media model is calculated numerically with coupled solid deformation-fluid seepage-convection and diffusion . The principal novelty of the model is that it takes into account volumetric deformation of both capillary and tissues resulting from capillary fluctuation. How solid deformation, fluid seepage, and convection-diffusion combine to affect oxygen transport is examined quantitatively: (1) Solid deformation is more significant in the middle of capillary, where the maximum value of volumetric deformation reaches about 0.5%. (2) Solid deformation has positive influence on the tissue fluid so that it flows more uniformly and causes oxygen to be transported more uniformly, and eventually impacts oxygen concentration by 0.1%-0.5%. (3) Convection-diffusion coupled deformation and seepage has a maximum (16%) and average (3%) increase in oxygen concentration, compared with pure molecular diffusion. Its more significant role is to allow oxygen to be transported more evenly. 相似文献
13.
Anton Sdobnov Gennadii Piavchenko Alexander Bykov Igor Meglinski 《Laser \u0026amp; Photonics Reviews》2024,18(2):2300494
Dynamic light scattering (DLS) is a well known experimental approach uniquely suited for the characterization of small particles undergoing Brownian motion in randomly inhomogeneous turbid scattering medium, including water suspension, polymers in solutions, cells cultures, and so on. DLS is based on the illuminating of turbid medium with a coherent laser light and further analyzes the intensity fluctuations caused by the motion of the scattering particles. The DLS-based spin-off derivative techniques, such laser Doppler flowmetry (LDF), diffusing wave spectroscopy (DWS), laser speckle contrast imaging (LSCI), and Doppler optical coherence tomography (DOCT), are exploited widely for non-invasive imaging of blood flow in brain, skin, muscles, and other biological tissues. The recent advancements in the DLS-based imaging technologies in frame of their application for brain blood flow monitoring, skin perfusion measurements, and non-invasive blood micro-circulation characterization are overviewed. The fundamentals, breakthrough potential, and practical findings revealed by DLS-based blood flow imaging studies, including the limitations and challenges of the approach such as movement artifacts, non-ergodicity, and overcoming high scattering properties of studied medium, are also discussed. It is concluded that continued research and further technological advancements in DLS-based imaging will pave the way for new exciting developments and insights into blood flow diagnostic imaging. 相似文献
14.
Christian Lehmann Nazli Alizadeh-Tabrizi Stefan Hall Sufyan Faridi Irene Euodia Bruce Holbein Juan Zhou Valerie Chappe 《Molecules (Basel, Switzerland)》2022,27(13)
Iron plays a critical role in the immune response to inflammation and infection due to its role in the catalysis of reactive oxygen species (ROS) through the Haber-Weiss and Fenton reactions. However, ROS overproduction can be harmful and damage healthy cells. Therefore, iron chelation represents an innovative pharmacological approach to limit excess ROS formation and the related pro-inflammatory mediator cascades. The present study was designed to investigate the impact of the iron chelator, DIBI, in an experimental model of LPS-induced acute lung injury (ALI). DIBI was administered intraperitoneally in the early and later stages of lung inflammation as determined by histopathological evaluation. We found that lung tissues showed significant injury, as well as increased NF-B p65 activation and significantly elevated levels of various inflammatory mediators (LIX, CXCL2, CCL5, CXCL10, IL-1𝛽, IL-6) 4 h post ALI induction by LPS. Mice treated with DIBI (80 mg/kg) in the early stages (0 to 2 h) after LPS administration demonstrated a significant reduction of the histopathological damage score, reduced levels of NF-B p65 activation, and reduced levels of inflammatory mediators. Intravital microscopy of the pulmonary microcirculation also showed a reduced number of adhering leukocytes and improved capillary perfusion with DIBI administration. Our findings support the conclusion that the iron chelator, DIBI, has beneficial anti-inflammatory effects in experimental ALI. 相似文献
15.
Spatial distribution of superficial blood vessels in human skin in vivo has been observed by using the double correlation Optical Coherence Tomography (OCT). To remove background noise, reduce the artifacts associated with patient motions and to increase the overall quality of the experimental OCT images an adaptive Wiener filtering technique has been employed. Fourier domain correlation has been subsequently applied to enhance spatial resolution of images of vascular network in human skin in vivo. Image processing has been performed on Graphics Processing Units (GPUs) utilizing Compute Unified Device Architecture (CUDA) framework in the frequency‐domain. This approach allows carrying out image processing in parallel significantly speeding up the computations. The presented results show that the double correlation method permits obtaining 2D/3D OCT images of subcutaneous microcirculation vascular network and its spatial distribution within the human skin with higher spatial resolution compare to the other OCT correlation‐based techniques developed earlier. 相似文献
16.
17.
郭仲三 《应用数学和力学(英文版)》1992,13(2):173-180
This paper deals with blood fiow caused by microvascular vasomotion with the focus on the effects of blood viscoelasticity on the pressure rise and wall resistance. It is shown that rnicrovascular vasomotion plays a role of the "second heart" of the body which is of importance in conveying blood, and that the effects of blood viscoelasticity greatly depend on the Weissenberg number and mean flow rate. 相似文献
18.
Study on cerebral microcirculation by Optical Doppler Tomography 总被引:1,自引:0,他引:1
Optical Doppler Tomography (ODT) provides a novel method to measure the blood flow velocity in vessels with the diameter at
micrometer scale. Rats with cranial window are used as a model, and the changes in the blood flow velocity of cerebral arterioles
in sensory cortex are measured in real time with an established ODT system, under electrical stimulation and drug administration.
The results show significant differences in the blood flow velocity between experimental groups and control groups, demonstrating
the feasibility of ODT in the cerebral microcirculation study. Compared with the conventional Doppler ultrasound, ODT provides
much higher spatial resolution, and thus holds a promising future in the application of the cerebral microcirculation study,
especially in the observation of the blood flow velocity in micrometer scale vessels.
Supported by the National Hi-Tech Research and Development Program of China (863 Program)(Grant No. 2006AA02Z4E0), the National
Natural Science Foundation of China (Grant Nos. 60378041, 60478040, 60878057 and 30770685), the Program for New Century Excellent
Talents in University (Grant No. NCET-04-0528), and the Opening Project of MOE Key Laboratory of Laser Life Science, South
China Normal University 相似文献
19.
Eric M. Jeffries Shintaro Nakamura Kee‐Won Lee Jimmy Clampffer Hiroyuki Ijima Yadong Wang 《Macromolecular bioscience》2014,14(11):1514-1520
Sufficient vascularization is critical to sustaining viable tissue‐engineered (TE) constructs after implantation. Despite significant progress, current approaches lack suturability, porosity, and biodegradability, which hinders rapid perfusion and remodeling in vivo. Consequently, TE vascular networks capable of direct anastomosis to host vasculature and immediate perfusion upon implantation still remain elusive. Here, a hybrid fabrication method is presented for micropatterning fibrous scaffolds that are suturable, porous, and biodegradable. Fused deposition modeling offers an inexpensive and automated approach to creating sacrificial templates with vascular‐like branching. By electrospinning around these poly(vinyl alcohol) templates and dissolving them in water, microvascular patterns were transferred to fibrous scaffolds. Results indicated that these scaffolds have sufficient suture retention strength to permit direct anastomosis in future studies. Vascularization of these scaffolds is demonstrated by in vitro endothelialization and perfusion. 相似文献