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Fiete D, Srivastava V, Hindsgaul O, Baenziger JU. A hepatic reticuloendothelial cell receptor specific for SO4-4GalNAc beta 1,4GlcNAc beta 1,2Man alpha that mediates rapid clearance of lutropin. Cell 1991; 67:1103-10. [PMID: 1662117 DOI: 10.1016/0092-8674(91)90287-9] [Citation(s) in RCA: 235] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have identified a receptor in hepatic endothelial and Kupffer cells that binds oligosaccharides terminating with the sequence SO4-4GalNAc beta 1,4GlcNAc beta 1,2-Man alpha (S4GGnM). This receptor can account for the rapid removal of the glycoprotein hormone lutropin, which bears unique Asn-linked oligosaccharides terminating in S4GGnM, from the circulation. Hepatic endothelial cells express 579,000 S4GGnM receptors at their surface and bind lutropin with an apparent Kd of 1.63 x 10(-7) M. Bound ligand is rapidly internalized. Binding does not require divalent cations, is reversed by incubation at pH 5.0 or below, and is inhibited by fucoidin but not by hyaluronate, heparin, chondroitin sulfate, or dextran sulfate. We propose that the S4GGnM-specific receptor represents a major mechanism for clearance of certain sulfated glycoproteins from the blood, including members of the glycoprotein hormone family.
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Zito SW, Srivastava V, Adebayo-Olojo E. Incorporation of [1-14C]-Isopentenyl Pyrophosphate into Monoterpenes by a Cell-Free Homogenate Prepared from Callus Cultures of Chrysanthemum cinerariaefolium. PLANTA MEDICA 1991; 57:425-7. [PMID: 17226179 DOI: 10.1055/s-2006-960140] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Callus culture of CHRYSANTHEMUM CINERARIAEFOLIUM (Trev.) Bocc. (Asteraceae), initiated with axillary buds from the plant, have been shown to produce chrysanthemyl alcohol and chrysanthemic acid. Incubation of a cell-free homogenate from the callus with [1- (14)C]-isopentenyl pyrophosphate demonstrated incorporation of radioactivity into chrysanthemyl alcohol and chrysanthemic acid as well as products from isopentenyl pyrophosphate isomerase (EC 5.3.3.2; isopentenyl diphosphate Delta (3)-Delta (2)-isomerase) and prenyltransferase activities (EC 2.5.1.11; allylic-terpene-diphosphate:isopentenyl diphosphate terpenoid-allyltransferase).
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178
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Skelton TP, Hooper LV, Srivastava V, Hindsgaul O, Baenziger JU. Characterization of a sulfotransferase responsible for the 4-O-sulfation of terminal beta-N-acetyl-D-galactosamine on asparagine-linked oligosaccharides of glycoprotein hormones. J Biol Chem 1991; 266:17142-50. [PMID: 1894609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The Asn-linked oligosaccharides on the glycoprotein hormones lutropin (LH) and thyrotropin terminate with the sequence SO4-4GalNAc beta 1-4GlcNAc beta 1-2 Man alpha-. Using a chemically synthesized trisaccharide GalNAc beta 1-4GlcNAc beta 1-2Man alpha 1-O(CH2)8COOCH3 (GGnM-MCO), we have developed a sensitive assay for the sulfotransferase responsible for the 4-O-sulfation of the terminal beta-D-GalNAc. GGnM-MCO is incubated with a bovine pituitary membrane extract and [35S]3'-phosphoadenosine 5'-phosphosulfate ([35S]PAPS). The sulfated product [35S]SGGnM-MCO is separated from [35S]PAPS, PAPS degradation products and endogenous sulfated products by a two-step procedure utilizing an Ecteola cellulose column and a Sep-Pak (C18) cartridge. Characterization of the [35S]SGGnM-MCO produced in the assay indicates that sulfate is incorporated exclusively on the 4-position of GalNAc. Linear incorporation of sulfate into GGnM-MCO can be maintained for greater than 10 h. GGnM-4-sulfotransferase has a pH optimum of 7.2, requires the presence of a reducing agent, and is stimulated by, but does not require, divalent cations. Initial velocity studies indicate an apparent Km (Henri-Michaelis-Menten equilibrium constant) for PAPS of 4 microM and for GGnM-MCO of 9 microM. Incorporation of sulfate into the trisaccharide is stimulated 3-fold by the presence of basic proteins including deglycosylated LH. The stimulation by deglycosylated LH suggests that the protein component of glycoproteins that bear oligosaccharides terminating with GalNAc-GlcNAc-Man- may modulate GGnM-4-sulfotransferase.
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179
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Skelton T, Hooper L, Srivastava V, Hindsgaul O, Baenziger J. Characterization of a sulfotransferase responsible for the 4-O-sulfation of terminal beta-N-acetyl-D-galactosamine on asparagine-linked oligosaccharides of glycoprotein hormones. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(19)47351-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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180
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Srivastava V, Jarzembski MA. Laser-induced stimulated Raman scattering in the forward direction of a droplet: comparison of Mie theory with geometrical optics. OPTICS LETTERS 1991; 16:126-128. [PMID: 19773857 DOI: 10.1364/ol.16.000126] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Comparison of Mie theory calculations of the internal electromagnetic source function for a 120-microm-diameter water droplet with geometrical optics suggests that the field enhancement located at the critical ring region encircling the axis in the forward direction of the droplet can support stimulated Raman scattering as found experimentally.
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181
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Chylek P, Jarzembski MA, Srivastava V, Pinnick RG. Pressure dependence of the laser-induced breakdown thresholds of gases and droplets. APPLIED OPTICS 1990; 29:2303-2306. [PMID: 20563165 DOI: 10.1364/ao.29.002303] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Laser-induced breakdown threshold intensities for helium, argon, xenon and clean air were measured as a function of pressure (p < 900 Torr) at wavelength lambda = 0.532 microm using the Nd:YAG laser with 6.5-ns pulse duration. Pressure dependence of the breakdown of a 50-microm diam water droplet in these gases was also investigated. For pure gases, different free electron generation processes and electron loss processes dominate in different pressure regions. The water droplets decrease the breakdown thresholds up to 3 orders of magnitude depending on the pressure of the particular gas surrounding the droplet. For the droplet in He, Ar, and clean air for p < 800 Torr, the breakdown at the threshold intensity occurs inside the droplet and is independent of pressure. For the droplet in Xe, the breakdown occurs inside the droplet for p < 140 Torr; however, for p < 140 Torr, the breakdown occurs outside the droplet and is dependent on pressure. Transition from the breakdown inside to outside the droplet takes place in the pressure region where the breakdown thresholds of the bulk liquid and the pure gas are approximately equal.
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182
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Srivastava V. Confluence of extended and localized states: Implications on the Mott-Cohen-Fritzsche-Ovshinsky model. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 41:5667-5673. [PMID: 9994449 DOI: 10.1103/physrevb.41.5667] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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183
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Peng S, Tilley R, Srivastava V, Hart R, Busbee D. Mitogen-activation of spleen cells in aged animals is potentiated by dietary restriction: a preliminary report. Mech Ageing Dev 1990; 52:71-8. [PMID: 2314129 DOI: 10.1016/0047-6374(90)90145-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Dietary restriction has been reported to be associated with increased life span and increased DNA repair capacity in both male and female rats and mice. We examined dietary restriction effects on immune system function and prolongation of life span in specific pathogen free rats and mice. In this preliminary report the authors show that dietary restriction is correlated with a dramatic increase in the lifespan of both male and female rats and mice in a pathogen free environment, and in the capacity of cultured splenocytes from those animals to initiate blastogenesis in response to antigenic stimulation.
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184
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Singh AK, Srivastava V. Novel 2-(Aryltelluro)Ethylmethyl-Sulfides Synthesis and Ligation with Palladium(II) and Platinum(II). J COORD CHEM 1990. [DOI: 10.1080/00958979009409725] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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185
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Singh AK, Srivastava V. Synthesis of Potential Tripodal Tellurium Ligands and Their Complexation with Mercury(II). J COORD CHEM 1990. [DOI: 10.1080/00958979009408181] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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186
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Jarzembski MA, Srivastava V. Electromagnetic field enhancement in small liquid droplets using geometric optics. APPLIED OPTICS 1989; 28:4962-4965. [PMID: 20555977 DOI: 10.1364/ao.28.004962] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The EM field enhancement in the forward direction of a dielectric sphere was derived leading to high-energy density in a critical ring region where, experimentally, the nonlinear processes a re observedf or small liquid droplets.
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187
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Reddy AS, Srivastava V, Guha-Mukherjee S. A tandemly repeated DNA sequence from Brassica juncea. Nucleic Acids Res 1989; 17:5849. [PMID: 2762161 PMCID: PMC318212 DOI: 10.1093/nar/17.14.5849] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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188
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Srivastava V, Hindsgaul O. Synthesis of the 3"-sulfate ester of beta-D-GalpNAc-(1----4)-beta-D-GlcpNAc-(1----2)-alpha-D-Manp. Carbohydr Res 1989; 185:163-9. [PMID: 2713871 DOI: 10.1016/0008-6215(89)84031-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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189
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Busbee D, Sylvia V, Curtin G, Peng S, Srivastava V, Tilley R. Age-related changes in DNA polymerase alpha expression. Exp Gerontol 1989; 24:395-413. [PMID: 2561101 DOI: 10.1016/0531-5565(89)90047-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
DNA polymerase alpha isozymes differing in specific activity and affinity of binding to DNA were purified from human fibroblasts derived from donors of different ages. Fetal-derived fibroblasts expressed a single, high-activity enzyme (A2), with high affinity of binding to DNA. Adult-derived fibroblasts exhibited two forms of DNA polymerase alpha, one identical to the fetal enzyme, and a second with about tenfold less activity showing low affinity of binding to DNA (A1). The ratio of DNA polymerase A2/A1 decreased dramatically with age, from 100% A2 in fetal-derived fibroblasts to about 94% A1 in fibroblasts derived from a 66-year-old donor. The DNA binding affinity of polymerase alpha A1 from adult-derived fibroblasts increased concomitant with a significant increase in activity when the enzyme was treated with phosphatidylinositol-4-monophosphate (PIP), or with inositol-1, 4-bisphosphate (I(1,4)P2). The enzyme reverted back to a less active form, with loss of the noncovalently bound I(1,4)P2, as a function of time. When permeabilized human fibroblasts with low DNA excision repair capacity were treated with 7,8-dihydrodiol-9,10-epoxybenzo(a)-pyrene (BPDE) in the presence of 32P-ATP, phosphatidylinositol, and cycloheximide, excision repair was initiated and 32P-labeled DNA polymerase alpha was recovered in the absence of de novo protein synthesis. DNA synthesis associated with either scheduled DNA synthesis or BPDE-initiated excision repair declined as a function of increased age in human cells. The data suggest that the decline in both DNA excision repair-associated and mitogen-activated DNA synthesis may be correlated with decreased total intracellular levels of DNA polymerase and with the decline in polymerase alpha activity as a function of age, that DNA repair-associated initiation of DNA synthesis in adult-derived cells may increase with activation of a pool of low activity DNA polymerase alpha, and that DNA polymerase alpha activity increases as a function of enzyme interaction with a component of the PI phosphorylation cascade.
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190
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Pinnick RG, Biswas A, Armstrong RL, Latifi H, Creegan E, Srivastava V, Fernandez G. Stimulated Raman scattering in micrometer-sized droplets: measurements of angular scattering characteristics. OPTICS LETTERS 1988; 13:1099-1101. [PMID: 19746137 DOI: 10.1364/ol.13.001099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Measurements of the angular scattering characteristics of elastic and stimulated Raman scattering (SRS) in single (nominal 20-microm-radius) water, ethanol, and CC1(4) droplets irradiated with 0.532-microm-wavelength radiation from a pulsed laser demonstrate that SRS is more isotropic than elastic scattering yet qualitatively mimics angularly smoothed elastic scattering patterns. The angular fine structure characteristic of the coherent elastic scattering process is lacking in SRS, regardless of whether the SRS derives from multiple orders of Stokes shifts, multiple resonances within a single Stokes shift, or single resonances within a single Stokes shift.
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191
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Srivastava V, Reddy AS, Guha-Mukherjee S. Transformation and regeneration of Brassica oleracea mediated by an oncogenic Agrobacterium tumefaciens. PLANT CELL REPORTS 1988; 7:504-507. [PMID: 24240402 DOI: 10.1007/bf00272742] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/1988] [Revised: 10/12/1988] [Indexed: 06/02/2023]
Abstract
A chimaeric neomycin phosphotransferase II (NPT II) gene was introduced in Brassica oleracea using an oncogenic strain of Agrobacterium tumefaciens harbouring Ti plasmid which contains Nos/NPTII in its T-DNA. The transformation of B. oleracea with the oncogenic Ti plasmid, resulted in regeneration of shoots and roots without any exogenous requirement of phytohormones. The presence of NPT II gene was determined by hybridization of Tn5 encoded NPT II gene with DNA of kanamycin resistant regenerated plants. The expression of NPT II was demonstrated by kanamycin phosphorylation assay. Several regenerated plants were obtained, a few of them were found to be morphological variants and a chlorophyll deficient mutant plant was also obtained.
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192
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Chyýlek P, Srivastava V, Pinnick RG, Wang RT. Scattering of electromagnetic waves by composite spherical particles: experiment and effective medium approximations. APPLIED OPTICS 1988; 27:2396-2404. [PMID: 20531771 DOI: 10.1364/ao.27.002396] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have measured the differential scattering cross sections (phase functions I(22)) and the normalized extinction and scattering cross sections (efficiences) of composite spherical particles. The size parameter x = 2pir/lambda was around 2pi. Composite spheres consisted of nonabsorbing matrix containing a small amount (1.6 and 2.7% by volume) of highly absorbing inclusions. Such composite particles may represent a realistic model of fog or cloud droplets containing small amounts of carbon or a composite atmospheric aerosol particle. We have compared measured data with those calculated using seven different effective medium approximations. We have found that the approximations of Bruggeman and Maxwell Garnett, the generalization of dynamic effective medium approximation derived by Chylek and Srivastava, and the experimental waveguide method of determination of the effective refractive index lead to an acceptable agreement between calculated and measured values. The reduced x(2) values for these approximations ranged between 0.6 and 2.0. The remaining three approximations (volume averages of refractive indices or dielectric constants and the Maxwell Garnett relation with matrix and inclusion materials interchanged) lead to reduced x(2) values between 4.0 and 12.0 demonstrating characteristics.
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193
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Pinnick RG, Biswas A, Chyălek P, Armstrong RL, Latifi H, Creegan E, Srivastava V, Jarzembski M, Fernández G. Stimulated Raman scattering in micrometer-sized droplets: time-resolved measurements. OPTICS LETTERS 1988; 13:494-496. [PMID: 19745943 DOI: 10.1364/ol.13.000494] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Time-resolved measurements of elastic scattering and stimulated Raman scattering (SRS) in micrometer-sized water and carbon tetrachloride droplets irradiated with a pulsed, frequency-doubled Nd:YAG laser (pulse width 8 nsec, lambda = 532 nm, peak intensity ~1 GW cm(-2)) are reported. Elastic scattering of light is instantaneous within our measurement error, estimated to be <+/-3 nsec. On the other hand, the first Stokes shift in water and multiple-order (through ninth-order) Stokes shifts in carbon tetrachloride are delayed from the elastically scattered light by 5-7 nsec. The delay in SRS is apparently a consequence of structure resonances within the droplet, which acts as an optical cavity with relatively high Q. Quasi-periodic peaks in SRS spectra of water droplets are shown to be associated with elastic-scattering structure resonances having the same mode order.
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194
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Pinnick RG, Chylek P, Jarzembski M, Creegan E, Srivastava V, Fernandez G, Pendleton JD, Biswas A. Aerosol-induced laser breakdown thresholds: wavelength dependence. APPLIED OPTICS 1988; 27:987-996. [PMID: 20523719 DOI: 10.1364/ao.27.000987] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Aerosol-induced loser breakdown thresholds have been measured for liquid droplets at wavelengths lambda= 1.064, 0.532, 0.355, 0.266 microm using a Nd:YAG laser with 5-10-ns pulse duration. Breakdown thresholds are 2-3 orders of magnitude below those for clean air and range from 4 x 10(7) to 3 x 10(9) W cm(-2) for nominal 50-microm diam droplets, depending on laser wavelength and droplet composition. Thresholds decrease with decreasing wavelength; they also decrease for droplets having a higher real refractive index. For water droplets the breakdown threshold intensity varies approximately as lambda(0.5). The wavelength dependence of breakdown thresholds can be qualitatively explained by considering (1) the effect of enhancement of internal fields and energy density within and near droplets and (2) the increasing importance of multiphoton absorption processes at shorter wavelengths. Laser transmission losses through the breakdown plasma and observations of the suppression of stimulated Raman scattering by the addition of small quantitites of absorbing material to water and carbon tetrachloride droplets are also reported.
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195
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196
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Chýlek P, Jarzembski MA, Srivastava V, Pinnick RG, Pendleton JD, Cruncleton JP. Effect of spherical particles on laser-induced breakdown of gases. APPLIED OPTICS 1987; 26:760-762. [PMID: 20454214 DOI: 10.1364/ao.26.000760] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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197
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Parashar RS, Srivastava V. Superconducting Tc enhancement in weakly disordered Ge-covered tin films. PHYSICAL REVIEW. B, CONDENSED MATTER 1985; 32:6048-6049. [PMID: 9937852 DOI: 10.1103/physrevb.32.6048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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198
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Pandeya SN, Srivastava V. Synthesis of some new amidine derivatives as potent hypoglycemic agents. PHARMACOLOGICAL RESEARCH COMMUNICATIONS 1985; 17:699-709. [PMID: 4048248 DOI: 10.1016/0031-6989(85)90087-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A series of S-arylformamidino-N-(alkyl/arylisothiourea) Cyclicamino dihydrochlorides were synthesised and screened for their hypoglycemic activity in normal as well as alloxanized diabetic rats. Some of the compounds (Id, Ie, Ih-1) showed more than 30% lowering of blood sugar level of Albino rats.
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199
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Pandeya SN, Pathak DP, Srivastava V. Synthesis of N'-aryl-N3-(substituted)-alpha, alpha'-thio-bis-formamidine dihydrochlorides and their effect on blood sugar level of albino rats. DIE PHARMAZIE 1983; 38:71-2. [PMID: 6844386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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200
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Srivastava V, Misra PC. Effect of endosulfan on plasma membrane function of the yeast Rhodotorula gracilis. Toxicol Lett 1981; 7:475-80. [PMID: 7195616 DOI: 10.1016/0378-4274(81)90096-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The effects of endosulfan on Rhodotorula gracilis cells are varied and concentration-dependent. They are exhibited as increased rate of respiration, retardation in pH-recovering activity of cell suspensions and loss in the rate or D-xylose uptake. The temperature dependence of sugar uptake indicated that endosulfan reacts with some membrane component(s).
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