Showing papers by "University of Hyderabad published in 1990"
TL;DR: This review summarizes information on heavy metal-binding proteins/peptides other than animal metallothioneins and suggests γ-glutamyl peptides may be involved in metal ion homeostasis and detoxification of excess metals.
80 citations
TL;DR: DABCO induces diastereoselective coupling of chiral acrylates with aldehydes to produce the corresponding 2-(1-hydroxyalkyl)acryls as mentioned in this paper.
57 citations
TL;DR: Hypothetically, a flavin containing plasma membrane redox system can pump protons out of guard cells on illumination with blue light and this electrogenic proton pump requires NAD(P)H but does not involve ATP/ATPase.
Abstract: . The effects of blue light on stomata are critically analysed. Blue-light-induced increase in stomatal conductance is preceded by membrane hyperpolarization, proton efflux, potassium uptake and malate synthesis in guard cells. Hypothetically, a flavin containing plasma membrane redox system can pump protons out of guard cells on illumination with blue light. It is proposed that this electrogenic proton pump requires NAD(P)H but does not involve ATP/ATPase.
54 citations
TL;DR: It is shown that strong competition between the absorption and emission of the cavity photons and the incoherent processes like atomic spontaneous emission and cavity decay effects result in new nonequilibrium states in cavity quantum electrodynamics that exhibit saturation, nonclassical character, and strong atom-cavity correlation.
Abstract: It is shown that strong competition between the absorption and emission of the cavity photons and the incoherent processes like atomic spontaneous emission and cavity decay effects result in new nonequilibrium states in cavity quantum electrodynamics. Such states can exhibit saturation, nonclassical character, and strong atom-cavity correlation.
33 citations
TL;DR: In this article, the authors generated hydrogen iodide from Bl3:N,N-diethylaniline complex and acetic acid, which readily adds to alkenes and alkynes in Markovnikov fashion to form alkyl and alkenyl iodides in good yields under mild conditions.
31 citations
TL;DR: The coherent field on the pumping transition leads to minima in the absorption spectra if the atomic population were in the state {vert bar}{ital f}{r angle}.
Abstract: We consider laser action on a transition involving an autoionizing state {vert bar}{ital a}{r angle} and an initially unpopulated state {vert bar}{ital f}{r angle}, the population of which builds up because of spontaneous emission and Raman processes. The autoionizing state is pumped by a coherent field. We discuss the transient amplification of the probe field on the lasing transition for a range of parameters. The coherent field on the pumping transition leads to minima in the absorption spectra if the atomic population were in the state {vert bar}{ital f}{r angle}. Such regions of minima can be used for obtaining gain even for long times.
30 citations
TL;DR: An approach for the obtention of the complete tetracyclic skeleton present in the novel lycopodium alkaloids of paniculatine-type is described in this article.
27 citations
TL;DR: An examination of the crystal structure of the title complex revealed three pathways for magnetic exchange that were analyzed on the basis of a model that assumes participation of the uncoordinated lattice water in propagating exchange interaction through H bonds.
Abstract: An examination of the crystal structure of the title complex revealed three pathways for magnetic exchange. Analysis of the bulk magnetic susceptibility data in the temperature range 5\char21{}303 K gave a value of J=-1.25 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ for the intradimer coupling. Single-crystal EPR spectra showed anomalous angular variation from which the molecular ssg tensor was derived using a decoupling procedure. The two intermolecular couplings [\ensuremath{\Vert}J'\ensuremath{\Vert}=0.0006(2) ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ at 300 K and 0.0001(2) ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ at 147 K, and J''\ensuremath{\ge}0.056 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$] involving multiatomic bridges were also derived from the EPR data. J'' involves equatorial-equatorial exchange between two coupled centers separated by 11.75 \AA{} and is stronger than the axial-equatorial exchange between centers separated by 7.73 \AA{}. The results were analyzed on the basis of a model that assumes participation of the uncoordinated lattice water in propagating exchange interaction through H bonds. Interpretation of the molecular ssg tensor resulted in an \ensuremath{\Vert}${\mathit{x}}^{2}$-${\mathit{y}}^{2}$〉 ground state with very little mixing of \ensuremath{\Vert}3${\mathit{z}}^{2}$-${\mathit{r}}^{2}$〉. The negligible electron density in the axial direction is responsible for the weak J'.
25 citations
TL;DR: Terminal hydroxyalkyl acrylates couple with aldehydes under the catalytic influence of DABCO producing the desired multifunctional molecules.
21 citations
TL;DR: In this article, a perturbational theoretical approach to describe the filament formation of very intense laser beams in self-focusing media is reviewed and linearized approximation is employed to describe results using both Sinusoidal as well as Gaussian perturbation models.
Abstract: Perturbational theoretical approach to describe the filament formation of very intense laser beams in self-focusing media is reviewed. Linearized approximation is employed to describe results using both Sinusoidal as well as Gaussian perturbation models. A phenomenological energy depletion criterion is introduced in order to explain some main features concerning filament formation. The sinusoidal perturbation model is further extended to take into account all the nonlinear terms neglected in linearizing the model in order to explain the experimentally observed diameter of the filaments. -
20 citations
TL;DR: In this article, pig liver acetone powder (PLAP) hydrolyzes trans-1-acetoxy-2 aryloxycyclohexanes enantio-selectively to produce the corresponding alcohols in high optical purities.
TL;DR: The microscopic theory is developed and the Fokker-Planck equation for the field distribution for such a laser (maser) system is derived.
Abstract: We show that laser and maser action is possible using atoms that have been prepared in dressed states. We develop the microscopic theory and derive the Fokker-Planck equation for the field distribution for such a laser (maser) system.
TL;DR: It is suggested that a rapid beneficial interaction exists between photosynthesis and respiration in protoplasts, even during short cycles of light and darkness.
Abstract: The respiratory uptake or photosynthetic evolution of oxygen by mesophyll protoplasts of pea (Pisum sativum L cv Arkel) were monitored during successive short (3-5 min) cycles of darkness and illumination The rate of respiration was nearly doubled after 3-4 short periods of illumination while there was a 15-20% enhancement in photosynthesis with cycles of illumination and darkness preceding illumination Such interaction between photosynthesis and respiration was statistically significant when bicarbonate was present in the reaction medium The inhibitors of photosynthesis [3(3,4-dichlorophenyl)-l,l-dimethylurea (DCMU), glyceraldehyde] decreased respiration after periods of illumination, whereas inhibitors of respiratory electron transport (Rotenone, antimycin A, NaN 3 ) suppressed photosynthesis, as well We suggest that a rapid beneficial interaction exists between photosynthesis and respiration in protoplasts, even during short cycles of light and darkness
TL;DR: Analytical results for the fluorescence spectrum of a two-level atom interacting with fully amplitude-modulated field at resonance are given and intensity-dependent changes in the peak widths and peak heights are presented.
Abstract: We give analytical results for the fluorescence spectrum of a two-level atom interacting with fully amplitude-modulated field at resonance. The results are valid for unequal longitudinal and transverse relaxation rates and follow the experimentally observed pattern. The intensity-dependent changes in the peak widths and peak heights are presented. Novel transient effects are predicted.
TL;DR: Results indicate that prolactin probably regulates DNA methylation in the liver and kidney of immature and adult rats.
Abstract: Prolactin is an important growth modulatory hormone in fetal and adult tissues. It stimulates DNA synthesis and enzymatic markers of the G1 phase of cell cycle in rat liver and other tissues. In this study the effects of prolactin on 5-methyl cytosine content in liver and kidney of rats was studied using HPLC. Prolactin treatment caused hypomethylation of DNA in the liver and kidney of immature rats at 48 h after treatment and the effect remained even at 72 h. Prolactin also caused hypomethylation of DNA in the kidney and liver of adult rats at 48 h after treatment. These results indicate that prolactin probably regulates DNA methylation in the liver and kidney of immature and adult rats.
TL;DR: In this article, a quantum statistical theory of a laser operating in the range of frequencies corresponding to the three-photon Mollow side band was formulated and a Fokker-Planck equation for the P-distribution of the field was obtained.
TL;DR: Racemic acetates of homoallyl alcohols have been enantio-selectively hydrolyzed by crude pig liver acetone powder (PLAP) to produce the corresponding alcohols in 56-72% optical purities as discussed by the authors.
TL;DR: The existence of nonlinearity-induced resonances in the structure that are missing in the linear theory are shown, and the possibility of having multivalued output with both the long- and short-range modes is shown.
Abstract: We present the exact numerical results for optical multistability with surface plasmons coupled through a dielectric slab with isotropic Kerr-type nonlinearity. We show the possibility of having multivalued output with both the long- and short-range modes and discuss the field profiles in the nonlinear medium. Moreover, we show the existence of nonlinearity-induced resonances in the structure that are missing in the linear theory.
TL;DR: The square of the displacement of the vortex lattice in high-temperature superconductors has been calculated by treating the fluxons as bosons, and the melting temperature has been deduced using the Lindemann criterion.
Abstract: The square of the displacement of the vortex lattice in high-temperature superconductors has been calculated by treating the fluxons as bosons, and the melting temperature has been deduced using the Lindemann criterion. Both the zero-point fluxon and the number-density-dependent contributions to the square of the displacement are found. The field-versus-temperature relationship near the melting line is deduced. The calculated position of the melting line is in reasonable agreement with the experimental value.
Journal Article•
TL;DR: Radiolabelling studies show a low rate of DNA synthesis in isolated abdomens, suggesting that hormonal factors from the anterior half of the larvae play a regulatory role in the DNA metabolism.
Abstract: Large amount of DNA is synthesized during larval development of Corcyra and this is conspicuously seen in the early-last instar. Ligation in early-last instar causes a decline in both DNA content and DNA concentration. Radiolabelling studies show a low rate of DNA synthesis in isolated abdomens, suggesting that hormonal factors from the anterior half of the larvae play a regulatory role in the DNA metabolism. Juvenile hormone I (JH-I) treatment of ligated early-last instar stimulates DNA synthesis with consequent increase in DNA content and DNA concentration.
TL;DR: In this article, a sphere theorem for non-axisymmetric Stokes' flow outside/inside a shear-free sphere is proved and proved in a special case.
TL;DR: The average hyperfine field at the inequivalent Fe(A,C) and Fe(B) sites in the pseudo-binary system Fe3-xMnx6 are presented in the entire composition range 0 ⩽ x⩽ 1.8, in which single phase alloys are formed.
TL;DR: It is concluded that under conditions of water stress in the presence of 10 mM or higher Mg2+, the oxygen evolving system in chloroplasts is rapidly inactivated.
Abstract: Thylakoids prepared from spinach (Spinacea oleracea L.) chloroplasts were exposed to osmotic stress in vitro in the presence or absence of different inorganic salts. By an hour after incubation in 1.0 M sorbitol and 10 mM (or more) MgCl2, the thylakoids lost approximately 80% of their photosystem (PS) II activity, but not PS I. The inhibition occurred only in presence of magnesium as indicated by the combinations of several cations/anions. The PS II activity was relatively insensitive to osmotic stress in the presence of diphenyl carbazide. We therefore conclude that under conditions of water stress in the presence of 10 mM or higher Mg2+, the oxygen evolving system in chloroplasts is rapidly inactivated.
TL;DR: The results of transformation and reversion studies suggests that glutamine auxotrophy is the result of a mutation in the gln A gene and that the gene can be transferred from one strain to another by transformation.
Abstract: Glutamine auxotrophic (Gln-) and l-methionine d,l-sulfoximine (MSX) resistant (MSXr) mutants of N. muscorum were isolated and characterized for nitrogen nutrition, nitrogenase activity, glutamine synthetase (GS) activity and glutamine amide, α-keto-glutarate amido transferase (GOGAT) activity. The glutamine auxotroph was found to the GOGAT-containing GS-defective, incapable of growth with N2 or NH4+but capable of growth with glutamine as nitrogen source, thus, suggesting GS to be the primary enzyme of both ammonia assimilation and glutamine formation in the cyanobacterium. The results of transformation and reversion studies suggests that glutamine auxotrophy is the result of a mutation in the gln A gene and that gln A gene can be transferred from one strain to another by transformation.
TL;DR: Results indicate that in testis, DNA methylation is differentially regulated during development and is controlled by gonadotropic hormones.
TL;DR: In this paper, the high-temperature superconductors YBa 2 Cu 3 O 7−δ and Bi 2 Sr 2 CaCu 2 O y, have been prepared by a new coprecipitation route using 8-hydroxy quinoline as the precipitating agent.
TL;DR: In this paper, the temperature dependence of thermoelectric power has been measured in the quasi-one dimensional charge density-wave (CDW) systems (NbSe4)103 I and (TaSe4 2 I).
Journal Article•
TL;DR: It is shown that the fat body cells of Corcyra cephalonica selectively incorporate LHPs during late-larval and prepupal development and 20-hydroxyecdysone treatment of early, mid or late-last instars causes a significant increase in uptake of all the three LHPs.
Abstract: Evidence is presented here to show that 20-hydroxyecdysone is essential for the activation of the larval fat body for differential uptake of larval haemolymph proteins (LHPs) By using radiolabelled LHPs it is shown that the fat body cells of Corcyra cephalonica selectively incorporate LHPs during late-larval and prepupal development Fluorographic analysis of the labelled fat body proteins from prepupal stage separated on sodium dodecyl-sulphate polyacrylamide gels suggests that the LHPs are sequestered without any degradation Although, during the last larval instar the uptake of all the three LHPs (LHP 1, LHP 2 and LHP 3) by the fat body cells is very low, 20-hydroxyecdysone treatment of early, mid or late-last instars causes a significant increase in uptake of all the three LHPs However, the response to hormone treatment was more pronounced in late-last instar when compared to early and mid-last instar
TL;DR: In this article, a three-step electrode mechanism was proposed for the transition from unbridged to bridged to doubly bridged structures of copper-II amino acid complexes with formaldehyde or acetaldehyde.
Abstract: Condensation products of several copper(II) amino acid complexes with formaldehyde or acetaldehyde have been prepared together with ethene-bridged copper(II) amino acid complexes Structures were deduced from analytical and spectral data Electronic spectral, esr and electrochemical behaviour at neutral and various low pH conditions were examined Spectra of the unbridged complexes indicate the formation of [CuL]+ type species at pHca 5, whereas the bridged complexes are stable at pH 3 The electrochemical behaviour of each complex is identical except for the doubly bridged complex These results are explained in terms of a three-step electrode mechanism The data show that the planarity of the complexes increases from unbridged, to bridged, to doubly bridged structures
TL;DR: In this paper, the exchange factor a in the self-interaction-corrected modification of the Slater Xα theory for the atoms Li-Ar was determined using an information-theoretical measure due to Kullback and Leibler, which is similar to the set of values determined previously using the criterion of making the statistical total energy equal to the Hartree-Fock total energy.