Permeability. Medical search. Frequent questions

Vascular permeability, often in the form of capillary permeability or microvascular permeability, characterizes the capacity of a blood vessel wall to allow for the flow of small molecules (drugs, nutrients, water, ions) or even whole cells (lymphocytes on their way to the site of inflammation) in and out of the vessel. (wikipedia.org)

Here, we look at how to extract the macroscopic flow properties of porosity and permeability from a fully resolved microscale submodel. (comsol.com)
If the porosity and permeability are not known, experimental results are necessary to quantify these material properties. (comsol.com)
By solving the Navier-Stokes equations (or its linear approximation for small Reynolds numbers, called Stokes flow or creeping flow) on the microscale geometry, the porosity and permeability of the porous medium can be extracted. (comsol.com)
Before we investigate the porosity and permeability of a porous medium, we must discuss the generation of the microscale geometry. (comsol.com)
We can use the postprocessing tools within COMSOL Multiphysics to extract the porosity and compute the permeability by using Darcy's law. (comsol.com)
In permeability and porosity? (moviecultists.com)
Does porosity increase with permeability? (moviecultists.com)
Are porosity and permeability inversely related? (moviecultists.com)
Permeability is another intrinsic property of all materials and is closely related to porosity . (moviecultists.com)
Does high porosity mean high permeability? (moviecultists.com)
Low porosity usually results in low permeability, but high porosity does not necessarily imply high permeability . (moviecultists.com)
How do you measure permeability and porosity? (moviecultists.com)
What is difference between porosity and permeability? (moviecultists.com)
When rock or soil that has high porosity has air spaces that are not connected, the rock or soil has low permeability even though it has high porosity. (moviecultists.com)
What factors affect porosity and permeability? (moviecultists.com)
Secondary porosity features, like fractures, frequently have significant impact on the permeability of the material. (moviecultists.com)
Why sand has a low porosity but a high permeability? (moviecultists.com)
Why is porosity and permeability important? (moviecultists.com)
The porosity and permeability of rocks is important in determining which rocks will make a good reservoir . (moviecultists.com)
The time dependent gas permeability is in keeping with the change of total porosity and contributive porosity of large capillary pores (100 to 1000 nm) with exposure time. (concrete.org)
Moreover, the change trends of stable time for gas permeability, total porosity, and contributive porosity of large capillary pores with w/b and admixture type are consistent. (concrete.org)
The stable time for the intrinsic gas permeability coefficient has a better correlation with that for contributive porosity of large capillary pores than that for total porosity. (concrete.org)
The intrinsic gas permeability coefficient stabilizes first, followed by contributive porosity of large capillary pores, which is the most important factor influencing the stable time for the intrinsic gas permeability coefficient, and total porosity stabilizes last. (concrete.org)
This work presents a fractal porous medium model to predict gob porosity and permeability for controlling methane flow and to predict air leakage into the gob. (cdc.gov)
This paper aims to examine the effects of porosity and permeability changes of the coal seam on methane emissions in an underground continuous miner section. (cdc.gov)

Abnormalities of red cell membrane cation permeability are seen in several hereditary disorders. (medscape.com)
Any disturbances in membrane cation permeability alter cellular hydration and can cause numerous effects, including hemolysis. (medscape.com)
In contrast, the primary abnormality in DHSt is a change in the relative membrane permeability to K + . Efflux of K + is increased 2- to 4-fold and results in cation depletion, with decreased intracellular osmolality and water loss. (medscape.com)
This experiment seeks to understand limited aspects of the permeability of the plasma membrane using the Elodea leaf membrane as model organism. (ukessays.com)
Some of the factors upon which permeability of the plasma membranes of biological organisms depend are differences in pH on opposite sides of the membrane, temperature, osmolarity, expression of certain membrane receptors and the concentration gradients of various molecules. (ukessays.com)
This experiment is very limited in scope and seeks to answer only the question of what is the time dependence for permeability of glycerol through the cell membrane. (ukessays.com)
Furthermore, outer membrane permeability of the host organism(s) will be adjusted in-process using moleculobiological tools. (boku.ac.at)
Membrane permeability will be characterized via atomic force microscopy and other analytical assays. (boku.ac.at)
The goal is to quantify and link outer membrane permeability to different mechanical properties of the cell. (boku.ac.at)
Overall, biologically active peptides should be produced extracellularly in soluble form by adjusting the membrane permeability of growing and producing cell. (boku.ac.at)
Figure 2 shows the relationships between membrane permeability and partition coefficients into (a) hexadecane, (b) olive oil, (c) octanol, and (d) ether. (harvard.edu)
The exact values of pm [membrane permeability] and Kp [partition coefficient] are given in Table 1. (harvard.edu)

The effect of Reynolds number on effective permeability was aslo investigated, and it was found that the transition from Darcian to non-Darcian flow occur at different Reynolds numbers for different fuel particles. (frontiersin.org)
Effective permeability is the ability of fluids to pass through pores of rocks or membranes in the presence of other fluids in the medium. (moviecultists.com)

Conclusion: Epac1 exerts a tonic inhibition of in vivo basal microvascular permeability. (uib.no)

Green banana and pectin improve small intestinal permeability and reduce fluid loss in Bangladeshi children with persistent diarrhea. (greenmedinfo.com)
To evaluate the effects of green banana and pectin (nondigestible, dietary sources of colonic shortchain fatty acids [SCFA]) on intestinal permeability, 57 boys (5-12 months) with persistent diarrhea (>or = 14 days) were given a week's treatment with a rice-based diet containing either cooked green banana (n = 19), pectin (n = 17), or rice diet alone (n = 21). (greenmedinfo.com)
Intestinal permeability was assessed before and after treatment by giving a lactulose-mannitol (LM) drink and measuring urinary recovery after 5 hr. (greenmedinfo.com)
Can a Leaky Gut (Intestinal Permeability) Cause Arthritis & Other Immune Reactions? (peoplespharmacy.com)
Leaky gut," more formally known as intestinal permeability, has been a term stealing the stage for quite a while now. (jjvirgin.com)
Recent studies have shown that GD/GO patients have a disturbed gut microbiome composition, which has been associated with increased intestinal permeability. (frontiersin.org)
This study hypothesizes that enhanced intestinal permeability may aggravate orbital inflammation and, thus, increase myofibroblast differentiation and the degree of fibrosis. (frontiersin.org)
Intestinal permeability was assessed by measuring serum lipopolysaccharide-binding protein (LBP), zonulin, TLR5, and TLR9 ligands. (frontiersin.org)
The increased intestinal permeability was accompanied by augmented expression of genes marking immune cell infiltration and encoding key proteins for immune cell adhesion, antigen presentation, and cytokine signaling in the orbital tissue. (frontiersin.org)
These results indicate that GO patients have enhanced intestinal permeability. (frontiersin.org)

The calculated effects of an abrupt increase in the permeability coefficients of K + , Na + , Cl − channels, or the NC cotransport rate coefficient on cell K + , Na + , and Cl − content and concentrations, water-volume (V/A) and MP (U). The data were calculated by using the software BEZ01B. (researchgate.net)
2016. A set of examples is presented in Figure 1 to show how changes in a single channel or transporter species (one permeability coefficient or rate constant) can alter the intracellular concentrations of all major ions, cell water content and the MP. (researchgate.net)
Finally, the relationship between stable time for the gas permeability coefficient and microstructure parameters was studied. (concrete.org)
For ordinary concrete, the gas permeability coefficient and the corresponding stable time increase with w/b. (concrete.org)

2017 ), which is affected by the fuel bed's air permeability. (frontiersin.org)
Wiseall, Andrew C. . 2017 Bentonite permeability at elevated temperature. (nerc.ac.uk)

The fracturing water injected into the underground gas reservoirs for development purposes has polluted the reservoirs, triggering a decrease in reservoir permeability and gas production. (mdpi.com)
Given its relevance to the exploitation of ultra-low permeability reservoirs, which account for a substantial proportion of the world's exploited and still unexploited reserves, in the present study the development of an adequate water injection system is considered. (techscience.com)

In this webinar we will review some results from the state-of-the-art integrated flow system for ZEISS Xradia Versa XRM, allowing for full steady state relative permeability experiments to be conducted at reservoir conditions. (zeiss.com)
We study the effects of fracturing water pollution on reservoir permeability with core experiments. (mdpi.com)
As low permeability reservoir development matures in the US, operators are now contending with the issue of field development. (spegcs.org)

Aim: Maintenance of the blood and extracellular volume requires tight control of endothelial macromolecule permeability, which is regulated by cAMP signalling. (uib.no)

This model is also validated by other's experimental results and can be used for explaining coal seam permeability reduction effects of CO injection in coal seams. (edu.au)

The air permeability of a fuel bed, which can be considered a porous medium, characterizes the ease with which air can pass through it. (frontiersin.org)
Permeability characterizes the resistance to flow through the pores. (comsol.com)

The results of four experiments investigating the effect of temperature on the permeability of a bentonite backfill are presented. (nerc.ac.uk)
In this paper, detailed laboratory experiments are conducted to investigate the permeability reduction effects during CO injections. (edu.au)

Analysis of engineering and hydrologic data from 15 previous soil studies, analysis of particle-size distribution, and analysis of descriptions of soil profiles show that 50 percent of the Sacramento Valley area has soils having permeabilities characterized by infiltration rates of less than 2 feet per day (0.6 meter per day). (usgs.gov)
Clay soils are known to have low permeability, which results in low infiltration rates and poor drainage . (moviecultists.com)

Which geologic factors control permeability development in geothermal systems? (usgs.gov)
The relatively rich data-set available for Dixie Valley, and the well-studied nature of the area affords the opportunity to characterize the geologic and lithologic factors that control permeability development at the local scale. (usgs.gov)
The authors "use an extensive compilation of results from hydrogeologic models to show that regional-scale (>5 km) permeability of consolidated and unconsolidated geologic units below soil horizons (hydrolithologies) can be characterized in a statistically meaningful way. (blogspot.com)

The loss of this tonic action increases baseline permeability, presumably by reducing the interendothelial permeability resistance. (uib.no)

The permeability rate is a measure of how fast applied irrigation water moves through the soil. (cvwd.org)
The Permeability Cells - Flexible Wall Permeameter for Soil Samples performs permeability tests on normal and contaminated soil samples. (worldoftest.com)
Subsoiling revives compacted soil by increasing its permeability. (irda.qc.ca)

Soils usually accept water rapidly at first and then at a reduced rate until the permeability steady state rate is reached. (cvwd.org)

The significance of this study is that it increases the ability to predict the air permeability of fuel beds in forests, which is essential for modeling wildland fire behaviors involving in porous fuel beds. (frontiersin.org)
A rock may be extremely porous, but if the pores are not connected, it will have no permeability. (moviecultists.com)

Walter A, Gutknecht J. Permeability of small nonelectrolytes through lipid bilayer membranes. (harvard.edu)
Diffusion of small nonelectrolytes through planar lipid bilayer membranes (egg phosphatidylcholine-decane) was examined by correlating [least square regression analysis] the permeability coefficients of 22 solutes with their partition coefficients between water and four organic solvents. (harvard.edu)

The results show that the apparent and intrinsic gas permeability coefficients of concrete both decrease with exposure time. (concrete.org)
The stable time for gas permeability coefficients of SF concrete is the shortest among admixture concrete, while that of BF concrete is the longest. (concrete.org)

Deairing Tanks are used with Triaxial and Permeability Test Systems to remove entrapped air in the water for use in Control Panels and Test Cells. (globalgilson.com)
Compared with the coal triaxial adsorption tests, it is suggested that the permeability equilibrium is not equal to the adsorption equilibrium. (edu.au)
The triaxial adsorption equilibrium process takes much longer time than that of permeability equilibrium process. (edu.au)

The results provide details of bentonite's intrinsic permeability, total stress, swelling pressure and porewater pressure during thermal cycles. (nerc.ac.uk)

The research is performed to find correlation between these phenomena of breathability and to predict the permeability based on only the air permeability measurement. (nih.gov)
The stable time for concrete permeability is of great significance to evaluate the permeability of concrete and predict the service life of actual engineering. (concrete.org)

As twist increases, the circularity and density of the yarn increases, thus reducing the yarn diameter and the cover factor and increasing the air permeability. (astm.org)
And the permeability of the inlet part of the core always increases, while the permeability of the rest of the core always decreases. (onepetro.org)

The present data suggest that acute exposure to cigarette smoke in smokers may decrease blood to airway permeability. (ersjournals.com)

Based on a test with an exposure time of more than 3 years in a natural tidal environment, the gas permeability and microstructure parameters of concrete with different water-binder ratios (w/b) and admixtures including fly ash (FA), slag (SG), silica fume (SF), and basalt fiber (BF) were tracked and tested. (concrete.org)
Then, the time-dependent gas permeability and main microstructure parameters and their stable time were investigated. (concrete.org)
The relative roles of parameters governing relative permeability, a crucial property for two-phase fluid flows, are incompletely known. (wiley.com)
However, previous research has suggested that the notional permeability is not only dependent on structural parameters, but also on hydraulic parameters. (tudelft.nl)

The hydrogen permeability for SrCe0.7Zr0.25Tm0.05O3−δ and SrCe0.7Zr0.25Yb0.05O3−δ is similar under our measurement window and shows the same hydrogen partial pressure dependency. (sintef.no)
Under short circuit condition, the hydrogen permeability increased significantly by more than one order of magnitude indicating that the hydrogen transport is limited by electronic conduction under open circuit conditions. (sintef.no)

To characterize the influence of viscosity ratio ( M ) and capillary number ( Ca ), we calculated relative permeabilities of nonwetting fluids ( k nw ) and wetting fluids ( k w ) in a 3D model of Berea sandstone under steady state condition using the lattice-Boltzmann method. (wiley.com)

Extended CTP was used to evaluate blood-brain barrier permeability in patients with SAH with and without global cerebral edema. (ajnr.org)
The effects of cigarette smoking on blood to airway pulmonary permeability to the low-molecular-weight solute urea were investigated, in an attempt to evaluate its use as a dilution marker for bronchoalveolar lavage (BAL) studies. (ersjournals.com)
Five minutes before bronchoscopy, 4 MBq 3H-water and 1 MBq 14C-urea were injected intravenously and biochemical urea assays and an indirect radiotracer method were used to evaluate permeability. (ersjournals.com)
The purpose of the present study as to evaluate the effect of changes in intravascular pressure and the inflammatory mediator bradykinin on rat mesenteric arterial and venous vascular permeability. (bvsalud.org)

The second is to optimize concrete mixture designs that meet strength, permeability, and workability criteria for construction. (trb.org)

peritoneal fluid accumulation is a common finding in many children with abdominal disorders and its generation secondary to increased vascular permeability. (bvsalud.org)

This paper presents a novel methodology for permeability prediction from micro-CT scans of geological rock samples. (springer.com)
The training data set for CNNs dedicated to permeability prediction consists of permeability labels that are typically generated by classical lattice Boltzmann methods (LBM) that simulate the flow through the pore space of the segmented image data. (springer.com)

The air permeability for different fuel beds were determined using experimental and theoretical methods. (frontiersin.org)
Material and Methods: Bovine teeth were divided into four groups (n=10), and the initial dental permeability was measured before the bleaching treatments, using a dental hydraulic permeability device. (bvsalud.org)

The pressure drop across the fuel bed samples were experimentally measured using a verified permeability testing rig. (frontiersin.org)
In this research, the impact on such a process of factors as permeability, row spacing, and pressure gradient is evaluated experimentally using a high-pressure large-scale outcrop model. (techscience.com)

Another technique uses multiphoton fluorescence intravital microscopy through which the flow is related to fluorescence intensity and the permeability is estimated from the Patlak transformation. (wikipedia.org)

Geothermal systems occur where subsurface permeability and temperature are sufficiently high to drive fluid circulation. (usgs.gov)
Results showed that CO 2 injection increased core permeability at high temperature and injection rate. (onepetro.org)

This study probes the role of the cAMP mediators rap guanine nucleotide exchange factor 3 and 4 (Epac1 and Epac2) for in vivo control of microvascular macromolecule permeability under basal conditions. (uib.no)

The need to find a correlation between air permeability and water vapour permeability is emphasised in order to facilitate the assessment of clothing comfort. (nih.gov)

Using the DNS-computed permeabilities, a physics-informed CNN (PhyCNN) is trained by additionally providing a tailored characteristic quantity of the pore space. (springer.com)

The use of epithelial lining fluid determinations in smokers ignores the additional and probably complex permeability changes. (ersjournals.com)

Cellular assays combined with metabolomics highlight the dual face of phenolics: From high permeability to morphological cell damage. (bvsalud.org)
The Caco-2 cellular permeability of phenolic aqueous extracts from blackcurrant press cake (BC), Norway spruce bark (NS), scots pine bark (SP), and sea buckthorn leaves (SB) was evaluated by combining high-resolution mass spectrometry and atomic force microscopy . (bvsalud.org)

Results: Epac1 / mice had constitutively increased transvascular macromolecule transport, indicating Epac1-dependent restriction of baseline permeability. (uib.no)
Part of the action of ANP to increase permeability in wild-type microvessels may involve inhibition of the basal Epac1-dependent activity. (uib.no)
Based on a literature study a hypothesis is made about the variables on which the notional permeability is dependent. (tudelft.nl)

Bradykinin (10 -5 M) significantly increased permeability in the MV but not in the MA. (bvsalud.org)

These physical fuel properties also affect permeability. (frontiersin.org)
Does pore size affect permeability? (moviecultists.com)
Carbon Dioxide Sequestration in Sandstone Aquifers: How Does It Affect the Permeability? (onepetro.org)

The larger the pore radius, the larger the apparent permeability . (moviecultists.com)
Figure 5(a) also shows that the effect of on the apparent permeability is much larger at low pore pressure than at high pore pressure. (moviecultists.com)
Thus, the increase in pore pressure decreases the effect of on the apparent permeability. (moviecultists.com)

1.1 This test method covers the measurement of the air permeability of textile fabrics. (astm.org)

In overhydrated hereditary stomatocytosis, the major defect is a marked asymmetrical increase in passive Na + and K + permeability. (medscape.com)
Such yarn extension would open up the fabric, increase the free area, and increase the air permeability. (astm.org)
The calculated effects of an abrupt increase in the permeability. (researchgate.net)

As long as the irrigation application rate does not exceed the permeability rate, runoff will not occur. (cvwd.org)

5.2 Air permeability is an important factor in the performance of such textile materials as gas filters, fabrics for air bags, clothing, mosquito netting, parachutes, sails, tentage, and vacuum cleaners. (astm.org)
The results show that there is a strong relation between air permeability and water vapour permeability for most of the textile material. (nih.gov)

5.4.2 Increasing yarn twist also may allow the more circular, high-density yarns to be packed closely together in a tightly woven structure with reduced air permeability. (astm.org)
Bentonite is a clay commonly proposed as the backfill in repository designs because of its high swelling capacity and very low permeability. (nerc.ac.uk)
API, i.e. of high solubility and low permeability. (who.int)

Bates, D. O. & Harper, S. J. Regulation of vascular permeability by vascular endothelial growth factors. (wikipedia.org)
5.4 Construction factors and finishing techniques can have an appreciable effect upon air permeability by causing a change in the length of airflow paths through a fabric. (astm.org)
The major factors affecting permeability rate are texture and density. (cvwd.org)
What are the two factors of permeability? (moviecultists.com)

The results show that the experimental method is preferred when determining the air permeability for natural forest fuel beds due to the variability in the size and shape of the particles. (frontiersin.org)
The results were expressed in percentage of increasing permeability (%) and data were submitted to ANOVA and Tukey's test. (bvsalud.org)
Results: Whiteness HP Maxx produced higher dental permeability (145.7±76.3) than Whiteness HP Blue (57.5±36.1) and Pola Office Plus (72.7±19.5), which did not differ from Opalescence Boost PF (101.4±46.3). (bvsalud.org)

An example of increased vascular permeability is in the initial lesion of periodontal disease, in which the gingival plexus becomes engorged and dilated, allowing large numbers of neutrophils to extravasate and appear within the junctional epithelium and underlying connective tissue. (wikipedia.org)

One of the main difficulties encountered in this process is the permeability reduction induced by CO injection and as a result, the injection rate is sharply dropped in the later period. (edu.au)
The dynamic permeability reduction effects are measured with the continuous CO injection under different confining pressure conditions. (edu.au)

Laboratory quantification of coal permeability reduction effect during" by Jia Lin, Ting Ren et al. (edu.au)
Objective: This study evaluated the effect of four bleaching agents on the dental permeability. (bvsalud.org)

The aim of this study is to provide a better understanding of the air permeability of the fuel beds in forests. (frontiersin.org)
Further study of blood-brain barrier permeability is needed to improve diagnosis and monitoring of global cerebral edema. (ajnr.org)

In low permeability scenario, the permeability reduction effects are severer. (edu.au)

However, the permeability change is not large and can mostly be accounted for by water viscosity changes. (nerc.ac.uk)

Anatomy54

Organisms17

Diseases9

Chemicals and Drugs114

Analytical, Diagnostic and Therapeutic Techniques and Equipment13

Phenomena and Processes44

Disciplines and Occupations2

Technology, Industry, Agriculture4

Information Science2

Health Care1

Capillary permeability1

Porosity25

Membrane12

Effective permeability2

Microvascular permeability1

Intestinal10

Coefficient4

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Extracellular1

Coal seam1

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Membranes2

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Triaxial3

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Parameters4

Hydrogen2

Steady state1

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Concrete1

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Temperature2

Vivo1

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Fluid1

Cellular2

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Textile2

High3

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