Browsing by Issue Date, starting with "1969"

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Observations on the effect of gonadal and adrenal cortical steroids upon thyroid gland in hypophysectomized catfish, Mystus vittatus (bloch)
(1969) T.P. Singh
Thyroid activity in response to graded doses of various gonadal and adrenal cortical steroids was studied in hypophysectomized catfish, Mystus vittatus. There was a steep fall in thyroidal radioiodine uptake within 5 weeks after hypophysectomy. Estrogen (15 μg/fish) and progesteron (20 μg/fish) treatments restored thyroidal activity to the level of control; whereas testosterone administration not only helped in restoring the normal activity but raised it about twice to that of control. Amongst three adrenal cortical steroids (hydrocortisone, deoxycortisone, and cortisone) tested, only cortisone (10 μg/fish) was potent enough to restore the thyroidal activity to the level of control. It appears that increased thyroid activity, in response to gonadal and adrenal steroids is independent of pituitary mediation. © 1969.
Recrystallization and grain growth observations in thin films of lead and palladium in the electron microscope
(1969) O.N. Srivastava
Recrystallization and grain growth, resulting from electron beam heating of local small areas inside an electron microscope, in thin polycrystalline films of lead and palladium have been studied. Large single crystal grains are found to result in this mode of annealing. The present observations seem to be unusual since it is known that, unlike bulk specimens, little or no recrystallization or grain growth occurs when thin metal films are annealed. It is suggested that the recrystallization and grain growth in this case are assisted by thermal stresses which are set up as a result of local heating, and are thus different from those resulting from direct annealing treatment. © 1969.
Complexes of some pyridine N-oxides and chloroanilines with zinc(II) halides
(1969) I.S. Ahuja; P. Rastogi
Complexes of pyridine N-oxide, 2-, 3-, 4-methyl-, 2,6-dimethyl-pyridine N-oxides and m- and p-chloroanilines with zinc(II) chloride, bromide, and iodide have been shown by molecular conductance, and i.r. (down to 222 cm. -1) spectral measurements to have tetrahedral structures in the solid state. Assignments for the Zn-O, Zn-N and Zn-X modes have also been made.
Kinetic behaviour of sweet almond α-galactosidase
(1969) P.M. Dey; O.P. Malhotra
The effect of temperature and pH on the activity of sweet almond α-galactosidase (α-galactoside galactohydrolase, EC 3.2.1.22) has been studied with melibiose and β-nitrophenyl α-d-galactoside (PNPG). Activation energies for the two substrates were found to be 12.4 and 19.0 kcal/mole, respectively. The pKm vs. t/T plots were linear for both substrates, and the enthalpies of binding were -7.3 and -10.2 kcal/mole for PNPG and melibiose, respectively. Changes in Km and vmax of melibiose with pH suggested the participation of a group with pK 5.75 in the enzymep-substrate binding and of another group with pK around 3 in the catalytic step. Similar studies with PNPG also revealed the presence of two groups (pK 3.4 or above and 6.7 or below), the pK values of which were strongly influenced by the substrate concentration. The group dissociating in the lower pH range appears to play a minor part only in the PNPG hydrolysis. In spite of apparently marked differences in the effect of temperature and pH, all the substrates appear to be hydrolysed at the same site on the enzyme molecule. The differences probably arose from differences in the mechanisms of the reaction or in the nature of the rate-limiting step in the two cases. © 1969.
Simple indole bases of Desmodium gangeticum (Leguminosae)
(1969) P.K. Banerjee; S. Ghosal
[No abstract available]
The Electron Microscopic Observation of Mechanical Twins in Gadolinium
(1969) J. Kumar; O.N. Srivastava
Mechanical twinning in gadolinium has been observed using an electron microscope. The analysis of electron diffraction patterns revealed that the twinning elements are K1 = K2 = (1012) and η1 = η2 = [1011]. The possible mechanism of genesis for these twins are investigated. It is found that the twins are nucleated due to thermal stresses set up in the films as a result of electron irradiation. There is no evidence for the pole dislocation mechanism to be operative in the present case, instead, the observations suggest that the twin formation is in accordance with the Bell‐Cahn mechanism. Copyright © 1969 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
Density of states effective mass of low temperatures in Sb-doped Ge
(1969) Y.P. Joshi; M.D. Tiwari; G.S. Verma
Density of states effective mass has been calculated from the thermal conductivity date for Sb-doped Ge in the temperature range 2 to 80°K. © 1969.
Amperometric determination of copper, cadmium and nickel and their binary mixtures with methyldithiobiuret
(Springer-Verlag, 1969) G.S. Deshmukh; R.K. Nandi
Copper, cadmium and nickel have been estimated amperometrically in ammoniacal ammonium tartrate and potassium nitrate (pH ∼ 8.0-9.5) using methyldithiobiuret as the titrant. The advantage of the oxidation potential of the reagent have been put to a practical use in these determinations. Furthermore, by the combined use of the cathodic current of a reducible ion (Cu2+) and the anodic current of the reagent simultaneous determination of the two components of binary mixtures (e.g., copper-cadmium and copper-nickel) in a single operation has also been achieved. The process is rapid and yields reproducible results within the limits of experimental errors. © 1969 Springer-Verlag.
Injective hulls of semi-simple modules over regular rings
(1969) A.K. Tlwary
The object of this paper is to provide an explicit construction of the injective hull of asemi-simple module over a commutative regular ring. © 1969 by Pacific Journal of Mathematics.
Synthesis of Some New N-o-Tolyl-N′-2-(Substituted) Benzothiazolylguanidines
(1969) P.N. Bhargava; Harihar Singh
[No abstract available]
Resonant scattering of phonons. I. CN-doped alkali halides
(1969) A. Kumar; A.K. Srivastava; G.S. Verma
The resonant scattering of phonons in KCl:CN and KBr:CN has been investigated. It is found that the ω4 dependence for the resonant scattering of phonons as obtained by Griffin and Carruthers for a similar resonance process in n-Ge does not explain published phonon-conductivity results in CN-doped alkali halides in the temperature range where the resonant-scattering dips occur. The results can, however, be described very well by the formula τr-1 ω2(ω2-ω02)2, which has been obtained by Kwok for n-Ge using a Green's-function approach. This approach is well known to be more suitable for frequencies close to the resonant frequencies where the usual perturbation techniques fail because of divergence difficulties. © 1969 The American Physical Society.
Dioxan complexes of cadmium(II) halides
(1969) I.S. Ahuja; P. Rastogi
[No abstract available]
On the grain growth kinetics in erbium oxide film
(1969) H.P Singh; O.N Srivastava
[No abstract available]
Binding Energy and Compressibility of Body‐Centered Cubic and Close‐Packed Hexagonal Sodium
(1969) V.K. Saxena; Q.S. Kapoor; D.L. Bhattacharya
The binding energies of the b.c.c. and c.p.h. phases of sodium have been computed using Hellmann‐type and modified Coulomb pseudopotentials. The binding energy of the c.p.h. structure is found to be about 2% more at 5°K than that of the b.c.c. structure as calculated from these pseudopotentials. The compressibility of the b.c.c. phase has also been calculated. The computed values give a fair agreement with the experimental results wherever available. Copyright © 1969 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
Otosclerosis and osteogenesis imperfecta
(1969) T.P. Srivastava; O.P. Gupta
[No abstract available]
Congenital macrodactyly
(1969) S.M. Tuli; N.N. Khanna; G.P. Sinha
Four cases of congenital macrodactyly are reported. Clinical, radiological, plethysmographic, operative and histological observations are presented. Findings of other workers and the pathogenesis of this rare condition are discussed. Principles of surgical treatment are briefly described. Plethysmographic observations and histological changes in the skin seem to have been mentioned for the first time. © 1969.
Effect of phase transformation on the spin susceptibility of sodium
(1969) Q.S. Kapoor; V.K. Saxena
Spin susceptibilities of the two phases of sodium have been computed using a Hellmann-type pseudopotential and a modified Coulomb potential. It is found that the spin susceptibility of the low temperature close-packed hexagonal structure at 5°K is about 3 per cent lower than that of the body-centred cubic structure. Experimental results of Schumacher and Vehse for the spin susceptibility and those of Knight for the Knight shift of sodium at cryogenic temperatures have partly been explained. © 1969.
Elastic scattering of 2.0 GeV/c negative pions off protons
(1969) S.K. Tuli
An experimental study of the elastic scattering of negative pions off protons at 2.0 GeV/c is presented. The differential cross section is fitted to a polynomial in cos θc.m. and the forward angular region as a diffraction peak. The results are compared with those from other bubble chamber experiments at neighbouring energies and discussed in terms of optical model and possible exchange trajectories. © 1969.
Effect of rhizosphere fungi on seed germination
(Martinus Nijhoff, The Hague/Kluwer Academic Publishers, 1969) K.M. Leelavathy
The effect of culture filtrates of some common rhizosphere fungi on the seed germination of Dichanthium annulatum, Bothriochloa pertusa and Setaria glauca was studied. Surface sterilized seeds were soaked in the fungal culture filtrates for 24 hours and after several washings in distilled water transferred to moist filter paper in Petri dishes and the percentage germination recorded. No significant inhibition or stimulation of germination was noticed in any of the treatments. The only exception was Trichoderma viride which inhibited the germination of D. annulatum seeds to some extent. © 1969 Martinus Nijhoff.
Morphology and genetics of pathogenicity of Puccinia sorghi Schw
(Kluwer Academic Publishers, 1969) M.S. Pavgi
[No abstract available]