Nonempirical calculations of molecular characteristics

A. I. Dement'ev

doi:10.1007/bf00746548

Electron microscopy of crystalline structure in thermotropic random copolymers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100089585 ◽

1991 ◽

Vol 49 ◽

pp. 1054-1055

Author(s):

Afzana Anwer ◽

S. Eilidh Bedford ◽

Richard J. Spontak ◽

Alan H. Windle

Keyword(s):

Electron Microscopy ◽

Crystalline Structure ◽

Liquid Crystalline ◽

Elevated Temperatures ◽

Random Copolymers ◽

Molecular Characteristics ◽

Scanning Calorimetry ◽

X Ray ◽

Identical Monomer ◽

Periodic Layer

Random copolyesters composed of wholly aromatic monomers such as p-oxybenzoate (B) and 2,6-oxynaphthoate (N) are known to exhibit liquid crystalline characteristics at elevated temperatures and over a broad composition range. Previous studies employing techniques such as X-ray diffractometry (XRD) and differential scanning calorimetry (DSC) have conclusively proven that these thermotropic copolymers can possess a significant crystalline fraction, depending on molecular characteristics and processing history, despite the fact that the copolymer chains possess random intramolecular sequencing. Consequently, the nature of the crystalline structure that develops when these materials are processed in their mesophases and subsequently annealed has recently received considerable attention. A model that has been consistent with all experimental observations involves the Non-Periodic Layer (NPL) crystallite, which occurs when identical monomer sequences enter into register between adjacent chains. The objective of this work is to employ electron microscopy to identify and characterize these crystallites.

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Effects of gamma ray on some molecular characteristics of in vitro regenerated Gerbera jamesonii Bolus

Bangladesh Journal of Botany ◽

10.3329/bjb.v39i2.7490 ◽

1970 ◽

Vol 39 (2) ◽

pp. 207-214

Author(s):

Nazma Akter ◽

RH Sarker ◽

MI Hoque

Keyword(s):

Gamma Ray ◽

Molecular Characteristics ◽

Gerbera Jamesonii

DOI: 10.3329/bjb.v39i2.7490Bangladesh J. Bot. 39(2): 207-214, 2010 (December)

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MICROCHEMICAL ANALYSIS OF HUMAN TIBIAL GROWTH CARTILAGE IN VARIOUS FORMS OF DWARFISM

Acta Endocrinologica ◽

10.1530/acta.0.0690659 ◽

1972 ◽

Vol 69 (4) ◽

pp. 659-688 ◽

Cited By ~ 16

Author(s):

V. Stanescu ◽

R. Stanescu ◽

J. A. Szirmai

Keyword(s):

Growth Plate ◽

Chondroitin Sulphate ◽

Epiphyseal Plate ◽

Molecular Characteristics ◽

Growth Disorders ◽

Normal Children ◽

Collagen Concentration ◽

Vitamin D Resistant Rickets ◽

Pooled Samples ◽

Tibial Epiphyseal

ABSTRACT Microchemical determinations of glycosaminoglycans and collagen were preformed in isolated histological zones from sections of tibial epiphyseal plate biopsies obtained from children with growth disorders (pituitary dwarfism, congenital myxoedema, Turner's syndrome, Noonan's syndrome, mucopolysaccharidosis type VI, vitamin D resistant rickets and achondroplasia). Alternate sections were used for histochemical localization of glycosaminoglycans and proteins. The values were compared with those found in comparable zones of the growth plate from normal children of the same age. The chondroitin sulphate concentration (% of defatted dry wt.) in the normal epiphyseal plate increased from the resting zone towards the proliferating/hypertrophic zone; collagen exhibited a reverse trend. In some of the pathological biopsies the concentration of chondroitin sulphate was slightly decreased whereas that of collagen was slightly increased. A marked increase in the collagen concentration was found in achondroplasia. The solubility profiles of the cetylpyridinium complexes of the chondroitin sulphate fraction showed three main peaks with slight but characteristic differences in the various zones of the normal cartilage plate. Significant shifts in the proportion of these peaks were observed in several pathological biopsies, indicating possible deviations from the normal molecular characteristics of the chondroitin sulphate. Analysis of the main chondroitin sulphate fraction, obtained from pooled samples of normal tibial growth plate after fractionation on the macroscale, indicated that all three peaks contained both chondroitin-4 sulphate and chondroitin-6 sulphate and that they probably differed in their molecular weight.

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Comparative Study of Highly Pathogenic Avian Infl uenza Strains Isolated in Ukraine in 2005 and 2008

Agricultural science and practice ◽

10.15407/agrisp1.01.068 ◽

2014 ◽

Vol 1 (1) ◽

pp. 68-71

Author(s):

A. Gerilovych ◽

B. Stegniy ◽

A. Stegniy ◽

M. Stegniy ◽

K. Smietanka ◽

...

Keyword(s):

Western Europe ◽

Rna Extraction ◽

Experimental Studies ◽

Molecular Characteristics ◽

Eastern European ◽

Highly Pathogenic ◽

Genetic Lineages ◽

Phylogenetic Studies ◽

Polymerase Chain ◽

Pathogenic H5n1

Objective. To research the molecular characteristics of two HPAI strains – A/Ch/Syvash/02/05/H5N1 and A/Ch/Krasnogvardeysk/58/08/H5N1, which were identifi ed as representatives of the highly pathogenic H5N1 viruses. Methods. RNA extraction, real-time polymerase chain reaction (PCR). Results. The phylogenetic studies revealed that the above mentioned strains belong to two various genetic lineages originated from the Eastern European strains isolated in 2005, but differ from the viruses introduced to the Central and Western Europe in 2005/2006, and also the lineages consisting of H5N1 viruses isolated in the Europe and Middle East in late 2007. Conclusions. Relying on experimental studies, it can be concluded that the strains of A/Ch/Syvash/02/05/H5N1 and A/Ch/Krasnogvardeysk/58/08/H5N1 are highly pathogenic.

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