Search Results - (Author, Cooperation:P. S. Pillai)

2016-04-23

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Adaptor Proteins, Signal Transducing/genetics/metabolism ; Adult ; Aged ; Aged, 80 and over ; Animals ; Bacterial Infections/etiology/*immunology ; Caspase 1/metabolism ; Caspases/metabolism ; Female ; Humans ; Immunity, Innate/genetics/*immunology ; Influenza A virus/*immunology ; Influenza, Human/complications/*immunology ; Interferon-beta/immunology ; Male ; Membrane Glycoproteins/genetics/metabolism ; Mice ; Monocytes/immunology ; Myxovirus Resistance Proteins/genetics/*physiology ; Neutrophils/immunology ; Orthomyxoviridae Infections/*immunology ; Respiratory Tract Infections/*immunology/microbiology ; Toll-Like Receptor 7/genetics/metabolism ; Viral Load ; Young Adult

1749-6632

Blackwell Publishing Journal Backfiles 1879-2005

Natural Sciences in General

Electronic Resource

1749-6632

Blackwell Publishing Journal Backfiles 1879-2005

Natural Sciences in General

Electronic Resource

1435-1536

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Zusammenfassung Die Kristallisation vonγ-bestrahlten Polyäthylen-Terephthalaten die in einem großen Temperaturbereich kristallisiert wurden, ist mit Hilfe der Differential-Kalorimetrie untersucht worden. Es wurde festgestellt, daß der Unterschied zwischen demAvrami-Exponenten der Tieftemperatur-Kristallisation und der von vorgeschmolzenen Proben ausgehenden Kristallisation nicht so ausgeprägt war wie bei dem unbestrahlten Polymer. Die Deckungsgleichheit der Tieftemperatur-Kristallisations-Isothermen entlang der log-Zeit-Achse und das Unvermögen der Vorschmelz-Isothermen, dasselbe zu tun, weisen jedoch darauf hin, daß die Kristallisations-Mechanismen verschieden sind. Die Kristallisations-Geschwindigkeit und die Kristallinität werden mit der Bestrahlung verändert, und zwar wird das ersterwähnte mit zunehmender Strahlungsdosis anfangs verzögert und dann beschleunigt, während das letztere ein Minimum bei 2 mrad hat. Die unterschiedlichen Geschwindigkeiten und Kristallinitäten werden diskutiert mit Rücksicht auf Kettenspaltung und Vernetzung. Das Verhältnis zwischen dem Kristall-Schmelzpunkt und der Kristallisations-Temperatur für den Vorschmelz-Prozeß ist wie in der Theorie vorhergesagt. Die Schmelzpunkte beim Tieftemperatur-Kristallisations-Prozeß sind höher als theoretisch, vermutlich durch Tempern oder weitere Rekristallisation.

Summary The crystallization ofγ-irradiated polyethylene terephthalate, crystallized over a wide range of temperatures, has been studied by differential scanning calorimetry. It was found that the difference between theAvrami exponents for the low temperature and pre-melt crystallization processes was not as pronounced as it was for the unirradiated polymer. The superposability of the low temperature crystallization isotherms along the log time axis and the inability of the pre-melt isotherms to do this suggest that the crystallization mechanisms are different. The rates of crystallization and the crystallinity are affected by irradiation, the former being first retarded and then speeded-up with dosage increase, whilst the latter is a minimum at 2 mrad. The differing rates and crystallinities are discussed with respect to chain scission and crosslinking. The relationship between the crystalline melting points and the crystallization temperatures for the premelt process is as predicted by theory. The melting points of the low temperature crystallization process are higher than those predicted by theory, annealing or further recrystallization being thought to have occurred.

Electronic Resource

0003-3146

Chemistry ; Polymer and Materials Science

Wiley InterScience Backfile Collection 1832-2000

Chemistry and Pharmacology

Physics

The phase structure of a styrene-butadiene-styrene block copolymer (mol. wt. 21 000-98 0000- 21 000) film cast from tetrahydrofuran/methyl ethyl ketone is studied by light scattering. The scattered intensity I corresponding to Vv, Hv, Vh, and Hh polarization directions is measured as a function of scattering angle. From the In I vs sin2 (θ/2) plots the domain sizes are found to be about 0.4 and 1.0 μ. The a values are independent of polarization directions. This proves that the domains are geometrically isotropic. The two sizes correspond to two correlation distances; the smaller value represents the extent of heterogeneity within a spherical domain and the larger valued the inter-domain separation distance.

1 Ill.

Electronic Resource

0730-2312

helper T cell-B cell interactions ; surface immunoglobulin ; Ia molecules ; membrane receptors ; signal transducers ; Life and Medical Sciences ; Cell & Developmental Biology

Wiley InterScience Backfile Collection 1832-2000

Biology

Chemistry and Pharmacology

Medicine

The question of whether surface immunoglobulin and Ia molecules have a signalling function in helper T cell-dependent activation of B cells has been evaluated. Two sources of B cells have been used, one a purified population of haptenbinding B cells, the other a B-cell lymphoma, CH12, with known antigen specificity. Evidence is presented that both immunoglobulin and Ia molecules are receptors actively involved in the initial activation of resting B cells. Nevertheless, the requirements for ligand binding to either receptor can be bypassed under appropriate conditions, and the implications of this result for the function of these molecules is discussed. With respect to B-cell Ia, the authors present data that demonstrate two distinct functions of this molecule, one as a restricting element for T-cell activation, the second as a signalling receptor for B-cell excitation. On the CH12 surface, the I-A molecule fulfills the former function, but T-cell interactions with I-A fail to result in B-cell stimulation, suggesting that B-cell la may limit helper T cell-B cell interactions. We suggest that the binding of antigen surface immunoglobulin and binding of helper T-cell receptors to the appropriate Ia molecule(s) results in the activation of genes that encode for a third class of membrane B-cell receptors, those that bind B-cell stimulating factors.

5 Ill.

Electronic Resource