Effect of initial stresses on the wave propagation in arteries

A theoretical analysis for the problem of wave propagation in arteries is presented. Blood is treated as a Newtonian, viscous incompressible fluid. On the basis of information derived from experimental investigations on the mechanical properties of wall tissues, the arterial wall is considered to be nonlinearly viscoelastic and orthotropic. The analysis is carried out for a cylindrical artery, under the purview of membrane theory, by taking account the effect of initial stresses. The motion of the wall and that of the fluid are assumed to be axisymmetric. Particular emphasis has been paid to the propagation of small amplitude harmonic waves whose wavelength is large compared to the radius of the vessel. By employing the equations of motion of the fluid and those for the wall, together with the equations of continuity, a frequency equation is derived by exploiting the conditions of continuity of the velocity of the arterial wall and that of blood on the endosteal surface of the wall. In order to illustrate the validity of the derived analytical expressions a quantitative analysis is made for the variations of the phase velocities as well as the transmission coefficient with frequency corresponding to different transmural pressures which relate to different initial stresses. Computational results indicate that phase velocities increase with the increase of transmural pressures.     

Solid-phase synthesis of ragweed allergen Ra5

A two-stage strategy was used to synthesize the 45-residue, four-disulfide-bonded ragweed protein allergen Ra5: (i) the protected linear chain was prepared by solid-phase, stepwise synthesis according to the sequence of the fully reduced protein; (ii) after removal from the resin and deprotection by hydrogen fluoride, the reduced chain was purified by gel filtration on Sephadex G-50 and allowed to fold “spontaneously” in the presence of oxidized dithiothreitol to form the disulfide links. The product (synthetic Ra5) was purified to disc-electrophoretic homogeneity by cycling through Sephadex G-50 and CM-Sephadex (overall yield: 6% theoretical). Synthetic Ra5 was closely similar in structure to the natural protein by amino acid analysis. polyacrylamide gel electrophoresis, tryptic peptide mapping, and circular dichroism spectra, as well asin vitro andin vivo immunoassays of antigenic/allergenic activities.     

Effect of amylose content on the lipids of mature rice grain

Most of the nonstarch lipids in brown rice (Oryza sativa) of three rices differing in amylose content were contributed by bran, germ, polish and subaleurone layer. Nonstarch lipids consisted of 82–91% neutral lipids (of which 73–82% were triglycerides), 7–10% phospholipids and 2–8% glycolipids. Linoleic, oleic and palmitic acids were the major fatty acids. Nonwaxy (24 and 29% amylose) milled rice had proportionally more starch lipids and less nonstarch lipids than waxy (2% amylose) milled rice. Starch lipids were mainly lysophosphatidyl choline, lysophosphatidyl ethanolamine and free fatty acids. The major fatty acids were palmitic and linoleic acids, followed by oleic acid.     

Lipids in developing and mature rice grain

The neutral fraction of nonstarch lipids in developing brown rice (Oryza sativa L., cv IR42) was accumulated up to 16 days after flowering (DAF), but phospholipids and glycolipids increased only up to 8 DAF. Fatty acids accumulated in nonstarch lipids until 12 DAF. However, the proportion of linolenic acid in the lipid fraction decreased and that of oleic acid increased during this period. Accumulation of fat-by-hydrolysis in the brown rice occurred until 20 DAF and followed closely that of starch. The proportion of linolenic acid decreased and that of linoleic acid increased until 16 DAF. The fatty acid composition of fat-by-hydrolysis and starch lipids were identical and fat-by-hydrolysis accounted for 48% by weight of starch lipids. Nonstarch lipids were mainly composed of triglycerides and were located in the bran and embryo of mature brown rice. Starch lipids were mainly composed of lysophosphatidyl choline, free fatty acids and lysophosphatidyl ethanolamine, and were located in the endosperm.     

Use of a combined Cellulomonas and Trichoderma cellulase preparation for cellulose saccharification

Summary An enzyme preparation from a mutant strain of Cellulomonas CS1-17 acts synergistically with low levels of Trichoderma reesei cellulase in saccharification of alkali-pretreated sugar cane bagasse and in assays of Filter Paper activity. Supplementation of the Cellulomonas preparation with 0.1 or 0.25 FPU.ml^- of T. reesei cellulase provides a preparation approximately equivalent to one using T. reesei alone at 1 FPU.ml^-1.     

Potential of Lentibacillus sp. NS12IITR for production of lipids with enriched branched-chain fatty acids for improving biodiesel properties along with hydrocarbon co-production

Extremophiles - Hypersaline environment is inhabited by array of microbes which have the potential to produce industrially important products. This study explored biomass and lipid production...     

Assignment of tyrosine-specific T-cell phosphatase to conserved syntenic groups on human chromosome 18 and mouse chromosome 18.

Phosphorylation of proteins on tyrosine is crucially involved in signal transduction and mitogenesis and is regulated by both kinases and phosphatases. Recently, a number of soluble and transmembrane receptor-linked protein tyrosine phosphatases (PTPase) have been characterized. Among these is a 48.4-kDa PTPase encoded by a cDNA isolated from a T-lymphocyte library by low-stringency screening with probes derived from placental PTPase 1B. A human T-cell PTPase (PTPT) cDNA and somatic cell hybrids were used to assign a PTPT gene to conserved syntentic groups on human chromosome 18 and on mouse chromosome 18. Two unlinked sequences, one on human chromosome 1, were also detected.     

Physiologic specialization of Colletotrichum corchori,Ikata and Yoshida,the causal organism of anthracnose of jute (Corchorus capsularis L.)

Summary Four varieties of jute,Corchorus capsularis, among fifteen screened were found to differentiate six races ofColletotrichum corchori. As regard virulence only two races, CS-1 and CS-2 among the six were of real importance.Besides recognising six races on four differential jute varieties, these were also differentiated from their cultural and morphological studies on laboratory medium as six cultural races.     

Applications of CRISPR/Cas9 technology for modification of the plant genome

Genetica - The CRISPR/Cas (Clustered regularly interspaced short palindromic repeats/ CRISPR associated protein 9) system was discovered in bacteria and archea as an acquired immune response to...     

Evolution of Escherichia coli in different carbon environments for 2,000 generations

Cellular energetics is thought to have played a key role in dictating all major evolutionary transitions in the history of life on Earth. However, how exactly cellular energetics and metabolism come together to shape evolutionary paths is not well understood. In particular, when an organism is evolved in different energy environments, what are the phenomenological differences in the chosen evolutionary trajectories, is a question that is not well understood. In this context, starting from an Escherichia coli K‐12 strain, we evolve the bacterium in five different carbon environments—glucose, arabinose, xylose, rhamnose and a mixture of these four sugars (in a predefined ratio) for approximately 2,000 generations. At the end of the adaptation period, we quantify and compare the growth dynamics of the strains in a variety of environments. The evolved strains show no specialized adaptation towards growth in the carbon medium in which they were evolved. Rather, in all environments, the evolved strains exhibited a reduced lag phase and an increased growth rate. Sequencing results reveal that these dynamical properties are not introduced via mutations in the precise loci associated with utilization of the sugar in which the bacterium evolved. These phenotypic changes are rather likely introduced via mutations elsewhere on the genome. Data from our experiments indicate that evolution in a defined environment does not alter hierarchy in mixed‐sugar utilization in bacteria.