Showing papers by "University of Madras published in 1970"
TL;DR: It appears from this study that the monomer unit has only a limited range of conformations centered around the values ϑ 1 = 180°, ϑ 2 = ±60°, 180°; ϑ 3 = 210–270° and χ = 30°, 220°.
82 citations
TL;DR: The study has been extended, in a limited way, to the conformation of the ring in the amino acid proline, and it is found that any one of the five atoms can be out of plane (either way), with the other four lying nearly in a plane.
77 citations
TL;DR: The significance of green metachromasia to Toluidine blue O, exhibited by vitelline cells of monogeneans and epicuticle of millipedes is elucidated, as due to phenolacid mucopolysaccharide complex, as synthetic phenols or synthetic phenol in combination with heparin or hyaluronic acid gave likewise a green colour to TolUIDine blue.
Abstract: The significance of green metachromasia to Toluidine blue O, exhibited by vitelline cells of monogeneans and epicuticle of millipedes is elucidated, as due to phenolacid mucopolysaccharide complex, as synthetic phenols or synthetic phenol in combination with heparin or hyaluronic acid gave likewise a green colour to Toluidine blue. The green colour is indicative of a metachromatic reaction is suggested, by its being eliminated or suppressed on treatment with metallic cations or detergent like Sodium oleate, as in other metachromatic reactions. A probable involvement of -OH groups in phenol-acid mucopolysaccharide complex is suggested.
52 citations
TL;DR: X-ray data compiled by Ramachandran and Ramakrishnan and available neutron diffraction data analysed in this paper are used for this purpose and different values of the parameters, A, b, B in the LS potential function can be obtained.
37 citations
TL;DR: An interpolation method is described, using cubic expressions in R and in θ, by which a smooth transition is obtained from the hydrogen bond function Vhb, in the range in which it is valid, to the nonbonded function Vnb, valid for large R.
37 citations
TL;DR: In this paper, the nonbonded interaction energy of disaccharides, mannobiose, galactobiose and polysaccharides mannan and galactan have been computed as a function of dihedral angles (φ,Ψ).
Abstract: The nonbonded interaction energy of disaccharides, mannobiose and galactobiose and polysaccharides mannan and galactan have been computed as a function of dihedral angles (φ,Ψ). The conformation (40°, -20°) has been preferred for the mannan chain from nonbonded interaction energy considerations. The O 5 ...O 3 ' type of intramolecular hydrogen bond has been found to be possible in the above conformation. Comparison of the allowed region of mannan with those of cellulose and xylan indicates that the monomer unit, in mannan chain has slightly higher freedom of rotation than that of cellulose and less than that of xylan. As in cellulose and mannan, the freedom of rotation of the monomer units in β-1,4' galactan is highly restricted. Unlike mannan (which prefers an extended conformation) the β-1,4' galactan prefers a helical conformation similar to amylose. Just as in amylose the O 2 ...O 3 ' type hydrogen bond between contiguous residues is also possible in β-1,4' galactan.
35 citations
TL;DR: The non-bonded interaction energies of cyclohexaamylose, hepta-and octa-amyloses, and cycloocta amylose have been investigated in this article.
34 citations
TL;DR: The enones 5a, 5b, 5c, 4d, 4a and 4b rearrange when treated with aqueous alkali to the diones 6a, 6b, 8 and 13 and acids 9 and 12 respectively as mentioned in this paper.
16 citations
TL;DR: It is suggested that protein-bound sugars may be transported, as such, to the epidermis, which may be the site of the final steps in chitin synthesis, which is supported by the observation that they are not involved in the nutritive metabolism of the crustacean.
Abstract: Blood sugars of the crustacean Emerita asiatica were studied during the moult cycle to examine their possible role in the synthesis of chitin, which takes place at the time of moulting. Blood sugars occur both in free state as well as bound with proteins, and show quantitative fluctuations in different phases of the moult cycle. The values of sugars were estimated in relation to total blood volume, to obviate the effects o absorption of water and consequent dilution of blood taking place during moulting. The data obtained suggest that the presence of glucosamine only during premoult stage may be due to resorption of chitin preparatory to the shedding of the cuticle. The fluctuations in the protein-bound blood sugars appear significant in the context of the synthesis of chitin, in view of the correlation seen between these and the chitin content. The above suggestion is supported by the observation that they are not involved in the nutritive metabolism of the crustacean. The protein-bound sugars do not appear to undergo further changes in the blood, as may be inferred by the absence of uridine diphosphate, and uridine diphosphate acetylglucosamine compounds, which have been suggested to be the more immediate precursors of chitin during the moult cycle of insects. It is suggested that protein-bound sugars may be transported, as such, to the epidermis, which may be the site of the final steps in chitin synthesis.
16 citations
TL;DR: Das Sekret der Mehlis-Drüse beeinflusst die Fermentaktivierung und bedingt, dass die von Dotterstockzellen synthetisierten Vorläufer von Sklerotin in situ nicht tanniert werden.
Abstract: Die Phenoloxydase der Vittellinzellen von Trematoden wirkt als inaktive Prophenoloxydase und bedingt, dass die von Dotterstockzellen synthetisierten Vorlaufer von Sklerotin in situ nicht tanniert werden. Das Sekret der Mehlis-Druse beeinflusst die Fermentaktivierung.
12 citations
TL;DR: Free amino acids of the haemolymph of a millipede Spirostreptus asthenes and a centipede Ethmostigmus spinosus and their concentrations were comparable to those of the primitive hemimetabolus insects.
TL;DR: In this article, the authors computed the nonbonded interaction energy for a pair of d -xylose residues joined through a β-(1→3) linkages, and also for the helical xylan chain, as a function of (ϕ, Ψ) the dihedral angles of rotation of the pyranose residues about the inter-residue glycosidic bonds C-1-O and O-C-3′.
TL;DR: In this article, the correlation between the endpoint energy and the shape factor coefficients including the modified B ij shape parameter D is thoroughly discussed and an ordered sequence of analysis which is physically very significant is developed.
TL;DR: In this paper, the molecular weight distribution of polyacrylamide, prepared by uranyl ion-photosensitized polymerization of acrylamides in visible light of wavelength 436 mµ, was studied in detail.
Abstract: The molecular weight distribution of polyacrylamide, prepared by uranyl ion-photosensitized polymerization of acrylamide in visible light of wavelength 436 mµ, was studied in detail. The polymer was fractionated and the experimental integral and differential distribution curves were drawn. The theoretical distribution function was derived from the kinetics of photopolymerization, assuming the rate constants calculated from previous studies. The theoretical and experimental molecular weight distributions were compared. The results support the mechanism proposed for the photopolymerization reaction.
TL;DR: In this paper, the formation of 1:1:1 complexes was inferred from the titration curves and their stability constants were reported, based on which they were used to predict the stability of uranyl ion-succinic-adipic complexes.
01 Nov 1970
TL;DR: It has been suggested that the mucus plays an important role in regulating the volume of water filtered besides the ciliary activity which is said to be under nervous control.
Abstract: The U-shaped endostyle of Amphioxus is known to secrete mucus. When the endostyle is separated from the two sides of the pharyngeal wall, the secreted mucus travels backwards along the groove without being lifted up. However, in an intact specimen the mucus is lifted up along the sides of the gill bar and spreads over the pharyngeal epithelium. As the mucus travels vertically upwards it acts as a moving “fly paper” to gather particles brought in by the water current.
TL;DR: In this paper, the second order rate constants (k2), acid-independent and acid-dependent rates (a and b), the corresponding rate constant ratio, kbka and the kinetic parameters, ΔE, ΔS, and A have been evaluated and discussed.
TL;DR: In this paper, the variation of the intrinsic viscosity and HUGGINS' constant with temperature, molecular weight and solvent was studied, and the thermodynamic interaction parameters χ, ψ, k etc., and the solubility parameter of the polymers were evaluated and discussed.
Abstract: Poly(methyl methacrylate) and poly(ethyl methacrylate) prepared by a benzoylperoxide catalysed polymerization process were fractionated. The variation of the intrinsic viscosity and HUGGINS' constant with temperature, molecular weight and solvent was studied. From the viscosity data the thermodynamic interaction parameters χ, ψ, k etc., and the solubility parameter of the polymers were evaluated and discussed.
Poly-(methylmethacrylat) und Poly-(athylmethacrylat), die mit Dibenzoylperoxid als Katalysator hergestellt worden waren, wurden fraktioniert. Die Anderung der Grenzviskositatszahl und der HUGGINS-Konstanten in Abhangigkeit von Temperatur, Molekular-gewicht und Losungsmittel wurde untersucht. Aus den Daten der Viskositat wurden die thermodynamischen Wechselwirkungsparameter χ, ψ, k usw. und die Loslichkeitsparameter bestimmt und diskutiert.
TL;DR: In this article, the authors make a systematic study of the properties of generalized phase operators and show that the coefficients of transformation from the number eigenstates to these are orthogonal polynomials in the eigenvalue parameter.
Abstract: Following the demonstration by Lerner that the phase (cosine and sine) operators for a harmonic oscillator can be much more general than the specific set considered earlier in the literature, we make a systematic study of the properties of such generalized phase operators We determine their eigenstates and show that the coefficients of transformation from the number eigenstates to these are, quite generally, orthogonal polynomials in the eigenvalue parameter Using these generalizedC andS operators the number-phase minimum uncertainty state is given Finally we point out that though the commutator [C, S] cannot be made to vanish, nevertheless one can constructC andS in such a way that their commutator has a vanishing expectation value with respect to all coherent states having a given mean occupation number exceeding unity
TL;DR: In this article, the photoproduction of π + from 12 C(0 +, g.s.) leading to the ground state of 12 N( J π = 1 + ) are studied by means of a transition amplitude obtained in the impulse approximation.
TL;DR: In this article, a general mechanism for the photopolymerization of vinyl monomers sensitized by uranyl ions is proposed and discussed, and the rate parameters kp/kp½ and kd′/ki were calculated from the polymerization kinetics at high monomer concentrations.
Abstract: Monomer acrylamide was used as quencher of uranyl ion fluorescence and Stern-Volmer plots were constructed at three monochromatic wavelengths of exciting radiation. The results indicated that the reaction between excited uranyl ion and monomer is one of energy transfer. The rate parameters kp/kp½ and kd′/ki were calculated from the polymerization kinetics at high monomer concentrations. A general mechanism for the photopolymerization of vinyl monomers sensitized by uranyl ions is proposed and discussed.
TL;DR: In this article, the presence of two-particle two-hole correlations in the ground state wave function of 16O brings theory into better agreement with the experimental results for the photoproduction of π+ from 16O leading to the four bound states J ƒ π = 0 −, 1 −, 2 −, 3 − in 16 N.
TL;DR: In this article, a reduced form of the Kemmer equation for spin one particles is derived, wherein the wave function, which has no redundant components, transforms locally (unlike in earlier reductions), and the reduced Hamiltonian is identical to the spin one specialisation of the general integer-spin Hamiltonian obtained from recent investigations on second quantizable relativistic wave equations having the Hamiltonian form.
TL;DR: In this paper, the authors studied the properties of automorphisms and *-isomorphisms of semi-simple L*-algebras and gave conditions under which an automorphism is automatically unitary.
Abstract: In this paper we are concerned with some properties of (algebraic)*automorphisms and *-isomorphisms of semi-simple L*-algebras. As a consequence of the inner product uniqueness theorem for L*-algebras established earlier ([4], see Theorem 1 below), it follows that every ^-isomorphism φ of a semi-simple L*-algebra L is necessarily topological and moreover φ is a semi-L*-isomorphism if L is simple (Corollary to Theorem 1). From these res alts we deduce that a *-isomorphism of a semi-simple Z/*-algebra can be expressed in terms of partial semi-L*-isomorphisms (Theorem 2). We give some conditions under which a \"^-automorphism is automatically unitary. While a ^-automorphism of any finite-dimensional simple L^-algebra is unitary (Corollary to Proposition 2), this result holds for an infinite-dimensional simple L*-algebra provided it is of classical type (Theorem 3). Under additional conditions on the auto norphism, the same result holds also for the general simple L*-algebra (see §2). Actually, it is our conjecture that the result is valid even without the additional conditions. We introduce a notion of regularity for automorphisms of semi-simple L*-algebras and show by means of a category argument that such automorphisms exist whenever the Z/*-algebras are separable (Theorem 4). For automorphisms which are inner, a criterion for regularity is obtained (Proposition 7) which coincides with the one given by Gantmacher for the regularity of automorphisms of semisimple Lie algebras.
TL;DR: Thiol group inhibitors and EDTA inhibited the cellulase activity completely whereas reducing agents and metal ions Fe++, Ca++ and Cu++ activated and the results are discussed in elation to pathogenicity towards the cotton plant.
Abstract: Cellulase of the cotton wilt pathogenFusarium vasinfectum was partially purified 19fold. The enzyme preparation had three pH optima at 5.4, 6.0 and between 8.0 and 8.4 and optimum temperature between 35 and 40°C. Irreversible denaturation of the enzyme resulted in 5 min below pH 1.5 and above 70°C. Thiol group inhibitors and EDTA inhibited the cellulase activity completely whereas reducing agents and metal ions Fe++, Ca++ and Cu++ activated. The results are discussed in elation to pathogenicity towards the cotton plant.
TL;DR: The results suggest that the preferred backbone conformations are independent of the presence and nature of side-group atoms beyond the γ-atom and vice versa.