scholarly journals Relationship of the Molecular Size and Charge Density of Polyoxometalates to Their anti-gp120-CD4-binding Activity

1994 ◽  
Vol 5 (6) ◽  
pp. 410-414 ◽  
Author(s):  
D. A. Judd ◽  
R. F. Schinazi ◽  
C. L. Hill

The ability of several classes of polyoxometalates to inhibit the interaction between HIV-1 gp120 and CD4 was assessed. No clear relationship was found between binding inhibition and the negative charge density on the anion portion of the polyoxometalate. However, a weak correlation was found with molecular size. There was a molecular weight threshold of 3800 g mol-1 above which no significant increase in potency was gained; the binding inhibition was nearly quantitative above this molecular weight.

2017 ◽  
Vol 144 ◽  
pp. 54-59 ◽  
Author(s):  
Marián Matejdes ◽  
Daisuke Himeno ◽  
Yasutaka Suzuki ◽  
Jun Kawamata

1997 ◽  
Vol 77 (3) ◽  
pp. 405-413 ◽  
Author(s):  
M. Susan Erich ◽  
Georgette M. Trusty

Liming of forest soils, currently practiced in Europe, may be necessary in the future in North America to counteract calcium (Ca) depletion due to whole tree harvesting. With current concerns over increasing carbon dioxide (CO2) levels in the atmosphere, the effects of forest practices such as liming on carbon (C) cycling in forest ecosystems has been receiving increasing attention. This laboratory study investigated the effect of an increase in pH on dissolved organic matter (DOM) in water extracts of organic horizons. Organic horizons were collected from nine forested sites, some predominantly hardwood and some predominantly softwood stand types. The soils were chemically characterized. Water extracts of limed and unlimed treatments of nine organic horizons were analyzed for pH, Al, Fe, Ca, C, and DOM negative charge density. Total luminescence fluorescence spectra were also obtained for each extract. The addition of lime (CaCO3) to organic horizons caused an average of 55% more C to be released than in unamended samples. Liming caused no significant changes in negative charge density of the DOM. Liming decreased organically-complexed aluminum (Al) and increased organically-complexed Ca. There was a negative correlation between Al concentration of extracts and fluorescence intensity. Chemical changes in the DOM released by liming were suggested by decreased fluorescence emission and excitation wavelengths due to liming. Hardwood samples did not respond differently than softwood samples with respect to DOM concentration, functional group concentration, or spectroscopic characteristics. However, there was a suggestion that particular tree species, such as cedar, may have unique effects on C concentrations and DOM chemistry. Key words: Lime, forest soil, dissolved organic matter, fluorescence


Blood ◽  
1972 ◽  
Vol 40 (1) ◽  
pp. 52-61 ◽  
Author(s):  
Marshall A. Lichtman ◽  
Robert I. Weed

Abstract The increased prevalence of tissue infiltration in some cases of monocytic leukemia may represent an enhanced ability of monocytes for tissue entry, continued cell proliferation, an increased life span in the tissues, or a combination of these three factors. Studies in this laboratory have shown that the normal myeloblast undergoes a process of cytoplasmic maturation that adapts it for marrow egress, tissue emigration, and particle ingestion. These include a reduction in surface negative charge density, increased ability to adhere to negatively charged surfaces, increased cytoplasmic deformability, more rapid motility, and enhanced phagocytic rate. In a subject with monocytic leukemia in whom tissue infiltration was a striking feature of the clinical disease, blood monocytes were broadly distributed in regard to their peripheral cytoplasmic characteristics. One portion of the cell population had a high surface negative charge density, was weakly adherent, weakly phagocytic, and poorly deformable, akin to blast cells. A second portion of the cell population had lower surface negative charge density, was adhesive, phagocytic, and readily deformable, akin to mature blood phagocytes. In five patients with myeloblastic leukemia in whom tissue infiltration was not prominent and in whom 92% of cells were myeloblasts, the blood leukocytes had a more homogeneous distribution of surface properties, and these properties were characteristic of immaturity. The increased prevalence of tissue infiltration in some cases of monocytic leukemia may be due to the presence of cytoplasmic maturation, which normally adapts the monocyte for tissue entry.


2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940058
Author(s):  
Le Dinh Vi ◽  
V. V. Dudich ◽  
G. G. Rabatuev ◽  
A. S. Lazarouk ◽  
A. V. Korotkevich

We have shown that the surface potential of anodic alumina films changes in time: immediately after the anodization process it was positively followed by the substantial decrease to negative values. Such variations of the surface potential can be associated with the negative built-in electric charge in alumina. The highest negative charge density occurs in the films formed in citric and phosphoric electrolytes.


1983 ◽  
Vol 22 (Part 1, No. 5) ◽  
pp. 892-892
Author(s):  
Motoichi Kawaguchi ◽  
Hiroyoshi Tanaka ◽  
Shigeru Suzuki

CrystEngComm ◽  
2018 ◽  
Vol 20 (25) ◽  
pp. 3559-3568 ◽  
Author(s):  
Takayuki Ban ◽  
Takahiro Wakita ◽  
Ryo Yokoyama ◽  
Tatsuya Miyake ◽  
Yutaka Ohya

Low negative charge density is required for the bottom-up synthesis of metalate nanosheets by an aqueous solution process.


1993 ◽  
Vol 264 (4) ◽  
pp. L387-L390 ◽  
Author(s):  
N. Inase ◽  
R. E. Schreck ◽  
S. C. Lazarus

To determine the role of heparin in mast cell exocytosis, we studied the effect of heparin on histamine release induced by compound 48/80 or calcium ionophore A23187 in canine mastocytoma cells (BR). Heparin caused concentration-dependent inhibition of compound 48/80-induced histamine release from mast cells (n = 4; P < 0.05) with a mean inhibitory concentration of 0.14 +/- 0.01 U/ml (mean +/- SE). Mean maximal inhibition was 69.3 +/- 2.0%. In contrast, heparin had no effect on calcium ionophore A23187-induced histamine release. Although benzyl alcohol, a preservative of pharmaceutical heparin, had no effect, purified heparin produced a similar inhibitory effect on compound 48/80-induced histamine release (n = 4; P < 0.05). The inhibitory effect of heparin on histamine release was rapid and was eliminated by washing cells. Dextran sulfate, a polysaccharide with negative charge density, produced a similar inhibitory effect on compound 48/80-induced histamine release (n = 4; P < 0.05). We conclude that heparin inhibits compound 48/80-induced exocytosis in mast cells probably by its negative charge density.


2007 ◽  
Vol 2007 (7) ◽  
pp. 1113-1122 ◽  
Author(s):  
Serena Leone ◽  
Antonio Molinaro ◽  
Luisa Sturiale ◽  
Domenico Garozzo ◽  
Evgeny L. Nazarenko ◽  
...  

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