2,027 research outputs found

    HLA-DR and -DQ antibodies in the sera of South India Parous women

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    HLA-A, -B positive sera of south Indian parous women were screened for the presence of HLA-DR and -DQ antibodies. The sera were absorbed with pooled platelets in a micro-method and screened against HLA-DR and -DQ typed B-lymphocytes panel. Out of fifty two sera, twenty were found to contain HLA-DR and -DQ antibodies. Seven sera were demonstrated to be specific for well defined DR and DQ antigen

    Agro-materials : a bibliographic review

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    Facing the problems of plastic recycling and fossil resources exhaustion, the use of biomass to conceive new materials appears like a reasonable solution. Two axes of research are nowadays developed : on the one hand the synthesis of biodegradable plastics, whichever the methods may be, on the other hand the utilization of raw biopolymers, which is the object of this paper. From this perspective, the “plastic” properties of natural polymers, the caracteristics of the different classes of polymers, the use of charge in vegetable matrix and the possible means of improving the durability of these agro-materials are reviewed

    Direct Measurement of Pyroelectric and Electrocaloric Effects in Thin Films

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    An understanding of polarization-heat interactions in pyroelectric and electrocaloric thin-film materials requires that the electrothermal response is reliably characterized. While most work, particularly in electrocalorics, has relied on indirect measurement protocols, here we report a direct technique for measuring both pyroelectric and electrocaloric effects in epitaxial ferroelectric thin films. We demonstrate an electrothermal test platform where localized high-frequency (approximately 1 kHz) periodic heating and highly sensitive thin-film resistance thermometry allow the direct measurement of pyrocurrents (<10 pA) and electrocaloric temperature changes (<2 mK) using the “2-omega” and an adapted “3-omega” technique, respectively. Frequency-domain, phase-sensitive detection permits the extraction of the pyrocurrent from the total current, which is often convoluted by thermally-stimulated currents. The wide-frequency-range measurements employed in this study further show the effect of secondary contributions to pyroelectricity due to the mechanical constraints of the substrate. Similarly, measurement of the electrocaloric effect on the same device in the frequency domain (at approximately 100 kHz) allows for the decoupling of Joule heating from the electrocaloric effect. Using one-dimensional, analytical heat-transport models, the transient temperature profile of the heterostructure is characterized to extract pyroelectric and electrocaloric coefficients

    Calculation of the Phase Behavior of Lipids

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    The self-assembly of monoacyl lipids in solution is studied employing a model in which the lipid's hydrocarbon tail is described within the Rotational Isomeric State framework and is attached to a simple hydrophilic head. Mean-field theory is employed, and the necessary partition function of a single lipid is obtained via a partial enumeration over a large sample of molecular conformations. The influence of the lipid architecture on the transition between the lamellar and inverted-hexagonal phases is calculated, and qualitative agreement with experiment is found.Comment: to appear in Phys.Rev.

    Mycorrhizal Dependency in Certain Indian Cotton Cultivars

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    Mycorrhizal dependencies of ten cotton cultivars were evaluated in the green houseusing completely randomized block design model. Acid-delinted seeds were sown inpolybags containing natural black soil. Plant growth, nutrient content and mycorrhizalcolonization levels were studied. Cotton cultivars exhibited mycorrhizal colonizationranging from 36.52 to 73.5 %. Plant dry weight and tissue Nitrogen content were positivelycorrelated whereas tissue Potassium was not correlated with the mycorrhization. Rootdiameter, number of root hairs and root length were varied among the cultivars. Rootdiameter was highest in the cultivar NHH 44, whereas root hair number was more in Suvin.Root hair length was maximum in the cultivar Suvin. Mycorrhizal dependency wasnegatively correlated with root hair number and root hair length. Maximum mycorrhizaldependency was exhibited by the cultivar Surya. The results showed the existence of strongmycorrhizal dependency in the cotton cultivars

    2, 4-Dimethyl-6-hydroxyacetophenone oxime and 3, 5-dibromo-2, 4-dimethyl-6- hydroxyacetophenone oxime as reagents and diethylamine as a synergist in the extraction and separation of metals

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    1022-10242,4-Dimethyl-6-hydroxyacetophenone oxime and 3,5- dibromo-2,4-dimethyl-6-hydroxyacetophenone oxime act as very good reagents for the extraction and separation of Cu(II), Ni(II), Co(II), Fe(III) and Mn(II). Addition of diethylamine as a synergist in the extraction system, not only increases the per cent extraction of the metals but also the molar absorbances of the complexes. The separation of the metals from one another, viz., Cu(II) from Ni(II), Cu(II) from Co(II) and Cu(II) and Ni(II) from Cr(III) becomes far more easier in the presence of diethylamine
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