Reliable operation of lab-on-a-chip systems depends on user-friendly, precise, and predictable fluid management tailored to particular sub-tasks the microfluidic process protocol their required sample fluids. Pressure-driven flow control, where fluids are delivered chip from pressurized feed vessels, simplifies even for multiple The achieved rates depend pressure settings, properties, pressure-...

Operating costs of merchant ships, related to fuel costs, has led the naval industry search alternatives current technologies propulsion power. A possibility is employ nuclear reactors like Russian KLT-40S, which a pressurized water reactor (PWR) and experience on civilian surface vessels. However, space weight are critical factors in project, addition operational safety costs. This work aims a...

Hypertension has been linked to an impaired dilator function of the coronary microvascular endothelium in vivo. However, the profile and mechanism of this dysfunction remain obscure. Thus, this study compared diameter responses to acetylcholine (ACH), bradykinin (BKN), and substance P (SP) between coronary microvessels (i.d.=106+/-4 microm) dissected from left ventricles of normotensive and hyp...

We present a compact microfluidic platform for the automated, multimodal assessment of intact small blood vessels. Mouse olfactory artery segments were reversibly loaded onto a microfluidic device and kept under physiological (i.e., close to in vivo) environmental conditions. For immunohistochemical endpoint protein analysis, automated on chip fixation and staining of the artery eliminated the ...

To determine whether simulated microgravity in rats is associated with vascular dysfunction, we measured responses of isolated, pressurized mesenteric resistance artery segments (157- to 388-microm ID) to vasoconstrictors, pressure, and shear stress after 28-day hindlimb suspension (HS). Results indicated no differences between HS and control (C) groups in 1) sensitivity or maximal responses to...

Caveolae in endothelial cells have been implicated as plasma membrane microdomains that sense or transduce hemodynamic changes into biochemical signals that regulate vascular function. Therefore we compared long- and short-term flow-mediated mechanotransduction in vessels from WT mice, caveolin-1 knockout (Cav-1 KO) mice, and Cav-1 KO mice reconstituted with a transgene expressing Cav-1 specifi...

Endothelial cells (ECs) govern smooth muscle cell (SMC) tone via the release of paracrine factors (eg, NO and metabolites of arachidonic acid). We tested the hypothesis that ECs can promote SMC relaxation or contraction via direct electrical coupling. Vessels (resting diameter, 57+/-3 microm; length, 4 mm) were isolated, cannulated, and pressurized (75 mm Hg; 37 degrees C). Two microelectrodes ...

the importance of groundwater as a source of water supply in arid, semi –arid areas in recent years due to the uncontrolled exploitation of groundwater have been doubled. uncontrolled exploitation has been caused a drop in the water table in many areas of the country, including this region. with replace methods of modern irrigation instead of traditional irrigation methods can prevent drop the ...

We have recently demonstrated that chronic hypoxia (CH) attenuates nitric oxide (NO)-mediated decreases in pulmonary vascular smooth muscle (VSM) intracellular free calcium concentration ([Ca2+]i) and promotes NO-dependent VSM Ca2+ desensitization. The objective of the current study was to identify potential mechanisms by which CH interferes with regulation of [Ca2+]i by NO. We hypothesized tha...

An increase in tissue blood flow requires relaxation of smooth muscle cells along entire branches of the resistance vasculature. Whereas the spread of hyperpolarization along the endothelium can coordinate smooth muscle cell relaxation, complementary signaling events have been implicated in the conduction of vasodilation. We tested the hypothesis that Ca(2+) waves propagate from cell to cell al...