Impregnation of S-layer protein isolated from extremophilic Bacillus Licheniformis NARW 02 onto titanium phosphate ceramic enhances uranium removal from aqueous solution

In the present study, bioceramic was prepared by impregnating surface layer protein (S-layer) isolated from extremophilic bacteria Bacillus licheniformis NARW 02 onto sol–gel-derived titanium phosphate (TiP) ceramic. The prepared bioceramic was used for adsorption of uranium ions from aqueous solution and compared with control lacking S-layer protein. The distribution coefficient value of TiP and bioceramic for uranium adsorption was 100.65 and 432.48 ml/g respectively. This study indicates that the bacterial S-layer can be potentially used to enhance the adsorption efficiency of the ceramics used in separation of uranium from waste water

Enhanced anticorrosion properties of nitrogen ions modified polyvinyl alcohol/Mg-Ag ions co-incorporated calcium phosphate coatings

Nitrogen ions (70 keV) were implanted on composite coatings containing polymer/Mg (magnesium)–Ag (silver) ions co-incorporated hydroxyapatite which is developed by microwave irradiation. Average crystallite size of modified coatings is reduced to 80% compared to pristine. The variation of bond strength of modified coatings is realized. The electrical resistance (77%), microhardness (4.3%), roughness (4.5 times) and pore size are enhanced on the modified coatings. Superhydrophilic surface is tuned to hydrophobic on implantation. At higher fluence (1×1017 ions/cm2) depicted an enhanced corrosion potential compared to the other coatings. Thus, the new insight of modified coatings is realized by correlating phase-structure, surface and anticorrosion

Peptide YY ablation in mice leads to the development of hyperinsulinaemia and obesity

Aims/hypothesis. Obese people exhibit reduced circulating peptide YY (PYY) levels, but it is unclear whether this is a consequence or cause of obesity. We therefore investigated the effect of Pyy ablation on energy homeostasis. Methods. Body composition, i.p. glucose tolerance, food intake and hypothalamic neuropeptide expression were determined in Pyy knock-out and wild-type mice on a normal or high-fat diet. Results. Pyy knock-out significantly increased bodyweight and increased fat mass by 50% in aged females on a normal diet. Male chow-fed Pyy −/− mice were resistant to obesity but became significantly fatter and glucose-intolerant compared with wild-types when fed a high-fat diet. Pyy knock-out animals exhibited significantly elevated fasting or glucose-stimulated serum insulin concentrations vs wild-types, with no increase in basal or fasting-induced food intake. Pyy knock-out decreased or had no effect on neuropeptide Y expression in the arcuate nucleus of the hypothalamus, and significantly increased proopiomelanocortin expression in this region. Male but not female knock-outs exhibited significantly increased growth hormone-releasing hormone expression in the ventromedial hypothalamus and significantly elevated serum IGF-I and testosterone levels. This sex difference in activation of the hypothalamo–pituitary somatotrophic axis by Pyy ablation may contribute to the resistance of chow-fed male knock-outs to late-onset obesity. Conclusions/interpretation. PYY signalling is important in the regulation of energy balance and glucose homeostasis, possibly via regulation of insulin release. Therefore reduced PYY levels may predispose to the development of obesity, particularly with ageing or under conditions of high-fat feeding

The effects of endogenous and exogenous androgens on cardiovascular disease risk factors and progression

Cardiovascular disease incidence rates have long been known to significantly differ between the two sexes. Estrogens alone fail to explain this phenomenon, bringing an increasing amount of attention to the role of androgens. Contrary to what was initially hypothesized, androgens seem to have an overall cardioprotective effect, especially in men. Recent studies and published data continue to support this notion displaying a consistent inverse correlation with atherosclerosis progression and cardiovascular disease both in regressive and prospective study models. Clinical studies have also revealed what seems to be a differential androgenic effect on various cardiovascular risk factors between men and women. Further insight indicates that in order to avoid confusion it may be also preferable to separately examine the effects of endogenous androgen levels from exogenous testosterone administration, as well as discern the differential results of low to normal and supraphysiological administration doses. This review summarizes old and recent data according to the above distinctions, in an attempt to further our understanding of the role of androgens in cardiovascular disease

Stochastic variation of transcript abundance in C57BL/6J mice

<p>Abstract</p> <p>Background</p> <p>Transcripts can exhibit significant variation in tissue samples from inbred laboratory mice. We have designed and carried out a microarray experiment to examine transcript variation across samples from adipose, heart, kidney, and liver tissues of C57BL/6J mice and to partition variation into within-mouse and between-mouse components. Within-mouse variance captures variation due to heterogeneity of gene expression within tissues, RNA-extraction, and array processing. Between-mouse variance reflects differences in transcript abundance between genetically identical mice.</p> <p>Results</p> <p>The nature and extent of transcript variation differs across tissues. Adipose has the largest total variance and the largest within-mouse variance. Liver has the smallest total variance, but it has the most between-mouse variance. Genes with high variability can be classified into groups with correlated patterns of expression that are enriched for specific biological functions. Variation between mice is associated with circadian rhythm, growth hormone signaling, immune response, androgen regulation, lipid metabolism, and the extracellular matrix. Genes showing correlated patterns of within-mouse variation are also associated with biological functions that largely reflect heterogeneity of cell types within tissues.</p> <p>Conclusions</p> <p>Genetically identical mice can experience different individual outcomes for medically important traits. Variation in gene expression observed between genetically identical mice can identify functional classes of genes that are likely to vary in the absence of experimental perturbations, can inform experimental design decisions, and provides a baseline for the interpretation of gene expression data in interventional studies. The extent of transcript variation among genetically identical mice underscores the importance of stochastic and micro-environmental factors and their phenotypic consequences.</p

Microstructure and interfacial reactions during active metal brazing of stainless steel to titanium

Microstructural evolution and interfacial reactions during active metal vacuum brazing of Ti (grade-2) and stainless steel (SS 304L) using a Ag-based alloy containing Cu, Ti, and Al was investigated. A Ni-depleted solid solution layer and a discontinuous layer of (Ni,Fe)2TiAl intermetallic compound formed on the SS surface and adjacent to the SS-braze alloy interface, respectively. Three parallel contiguous layers of intermetallic compounds, CuTi, AgTi, and (Ag,Cu)Ti2, formed at the Ti-braze alloy interface. The diffusion path for the reaction at this interface was established. Transmission electron microscopy revealed formation of nanocrystals of Ag-Cu alloy of size ranging between 20 and 30 nm in the unreacted braze alloy layer. The interdiffusion zone of β-Ti(Ag,Cu) solid solution, formed on the Ti side of the joint, showed eutectoid decomposition to lamellar colonies of α-Ti and internally twinned (Cu,Ag)Ti2 inter- metallic phase, with an orientation relationship between the two. Bend tests indicated that the failure in the joints occurred by formation and propagation of the crack mostly along the Ti- braze alloy interface, through the (Ag,Cu)Ti2 phase layer