What's the difference between diffusion and percolation?

Diffusion


Definition:

  • (n.) The act of diffusing, or the state of being diffused; a spreading; extension; dissemination; circulation; dispersion.
  • (n.) The act of passing by osmosis through animal membranes, as in the distribution of poisons, gases, etc., through the body. Unlike absorption, diffusion may go on after death, that is, after the blood ceases to circulate.

Example Sentences:

  • (1) The Na+ ionophore, gramicidin, had a small but significant inhibitory effect on Na(+)-dependent KG uptake, demonstrating that KG uptake was not the result of an intravesicular positive Na+ diffusion potential.
  • (2) The femoral component, made of Tivanium with titanium mesh attached to it by a new process called diffusion bonding, retains superalloy fatigue strength characteristics.
  • (3) The diffusion of Myocamicin in the prostatic tissue of patients undergoing prostatectomy after a single oral dose of 600 mg has been studied.
  • (4) The preembedding method also disclosed diffuse cytosolic immunoreactivity.
  • (5) The clinical aspects, the modality of onset and diffusion of the lymphoma, its macroscopic and histopathological features and the different therapeutic approaches are discussed.
  • (6) The kidney disease was characterized by diffuse beaded deposition of rat gammaglobulin along the glomerular capillaries and proteinuria.
  • (7) We identified four distinct clinical patterns in the 244 patients with true positive MAI infections: (a) pulmonary nodules ("tuberculomas") indistinguishable from pulmonary neoplasms (78 patients); (b) chronic bronchitis or bronchiectasis with sputum repeatedly positive for MAI or granulomas on biopsy (58 patients, virtually all older white women); (c) cavitary lung disease and scattered pulmonary nodules mimicking M. tuberculosis infection (12 patients); (d) diffuse pulmonary infiltrations in immunocompromised hosts, primarily patients with AIDS (96 patients).
  • (8) Sera from three of these patients gave a precipitin band in gel diffusion tests identical to that produced by a monospecific rabbit anti-E. granulosus antigen 5 serum, when tested against whole hydatid fluid.
  • (9) A constellation of histologic lesions was identified in brain (diffuse meningoencephalitis with bilaterally symmetrical thalamic necrosis), liver (pericholangiohepatitis), lung (pneumonitis), and spleen (lymphoid hyperplasia); this tetrad is apparently unique to this model system.
  • (10) Diffuse Ga-67 uptake in the kidneys was seen due to renal involvement with this disorder.
  • (11) Thus, whereas CD3-associated molecules isolated from polyclonal CD3+WT31+ populations (expanded in IL 2 under the same culture conditions) appeared as diffuse bands, CD3-associated molecules isolated from CD3+WT31- populations displayed a homogeneous molecular mass.
  • (12) The diffuse reaction product seen in basement membranes of ganglion and nerve may also be artifact.
  • (13) Here we determine the position of bound ADP diffused into the recA crystal.
  • (14) In contrast, boundary layer diffusion is operative in the release from the matrixes prepared by compression of physical mixtures.
  • (15) Medium molecules have been detected by two methods, gel filtration and screening technique, in patients with diffuse purulent peritonitis and with chronic renal insufficiency.
  • (16) This may be because the epithelium restricts diffusion of the drug or due to the production of a non-prostanoid factor which inhibits smooth muscle responsiveness.
  • (17) Ten of 11 diffuse poorly differentiated lymphocytic lymphomas were composed of cells with large amounts of surface immunoglobulin, whereas only 1 of 5 diffuse well differentiated lymphocytic tumors contained such abundant surface immunoglobulin.
  • (18) Thirty-six lesions imaged as vascular malformations with abnormal vessels or diffusely increased activity.
  • (19) We therefore conclude that the protective effect displayed by solid grafts might be a local process dependent on the release of diffusible trophic agents.
  • (20) These results demonstrate, in living human hearts, that diffuse coronary atherosclerosis is often present when coronary angiography reveals only discrete stenoses.

Percolation


Definition:

  • (n.) The act or process of percolating, or filtering; filtration; straining. Specifically (Pharm.), the process of exhausting the virtues of a powdered drug by letting a liquid filter slowly through it.

Example Sentences:

  • (1) As soon as the component with the lower mechanical stability is percolating the powder system, tablet hardness is controlled entirely by this component.
  • (2) This group consisted of 101 cases of whom 38 underwent semen treatment with Centrifugation on a Discontinuous Percoll Gradient (CDPG) and 63 with Pellet Swim-up (PS); the control group was made up of 31 normospermic patients where the semen was treated by PS.
  • (3) The attempt to fractionate the testicular cells by centrifugation in the continuous and discontinuous Percoll gradient was undertaken.
  • (4) The platelet subpopulations were separated with discontinuous gradients of Percoll.
  • (5) By using Percoll discontinuous density gradient centrifugation, peripheral blood nonphagocytic and nonadherent mononuclear cells were divided into the low and high density fractions for which natural killer (NK) cells and T cells were enriched, respectively.
  • (6) We conclude that both localized memory and percolation are possible in stimulatory idiotypic networks.
  • (7) The effect of activated PMN was tested on the motility of Percoll-washed spermatozoa in the presence and absence of reactive oxygen species scavengers or seminal plasma (whole or fractionated).
  • (8) To cope with this problem, in 27 IVF cycles, sperm selection was performed by centrifugation on discontinuous Percoll density gradient.
  • (9) Thirdly, the discontinuous percoll density gradient centrifugation was used to separate P. carinii cysts.
  • (10) Fractionation by Percoll density centrifugation of peripheral blood leucocyte cells, from atopic subjects with seasonal hay fever, unmasked IgE-B cell populations whose individual capacities to synthesize IgE in vitro were obscured in cultures of unfractionated B cells.
  • (11) Inspection of the cavity margins revealed absence of percolation at the dentin margins.
  • (12) In general, IEL of satisfactory yield and of good viability were obtained with EDTA treatment of the gut tissues, followed by rapid passages of the resultant cells through nylon-wool columns and centrifugation on two-step Percoll density gradients (45% and 80%).
  • (13) Basolateral membranes obtained by self-orienting Percoll-gradient centrifugation were treated with 5 mM CaCl2 to minimize the cross-contamination by brush border membranes.
  • (14) Percoll-purified high density small lymphocytes had little or no migratory capacity under these conditions, requiring a longer incubation time (4 hr) for consistent migration.
  • (15) Guinea pig marrow cell suspensions were first enriched for megakaryocytes by density equilibrium centrifugation in continuous Percoll density gradients.
  • (16) Using Percoll density gradient centrifugation, 1,25(OH)2D3 receptors could be localized in the basal cell fraction.
  • (17) After introduction of erythrocyte targets, there was a 20- to 30-min delay before initiation of phagocytosis that was not observed with monocytes prepared by the standard Percoll-gradient technique.
  • (18) To accomplish this, blood was obtained from patients with ragweed AR, granulocytes were isolated and fractionated by continuous density Percoll gradients, and the density distribution of these cells was determined after centrifugation.
  • (19) A cellular compartment from brown adipose tissue (BAT) of newborn rats was isolated by Percoll-density-gradient centrifugation and was shown to proliferate and to undergo adipose conversion in vitro in primary culture.
  • (20) Collagenase-dispersed cells from human chorion laeve were examined on Percoll gradients.