43 research outputs found
Effect of Plastic Deformation on the Magnetic Properties 304 Stainless Steel During Tensile Loading
The present investigation addresses effect of tensile deformation on the magnetic properties of virgin 304SS as well as cold rolled samples containing a low
volume fraction of 12% and 17% martensite. In-situ Non-destructive evaluation (NDE) techniques by magnetic Barkhausen emission (MBE) and magnetic
hysteresis loop (MHL) measurement were used for evaluation of plastic deformation during tensile loading. Both the techniques indicated different stages of variation in
magnetic properties with progressive plastic deformation. The trend of coercivity and Barkhausen measurements also throw light on the ductile and brittle fracture occurring in virgin and cold worked samples with validation using SEM
fractography
Enhancer of Zeste Homolog 2 Induces Pulmonary Artery Smooth Muscle Cell Proliferation
Pulmonary Arterial Hypertension (PAH) is a progressively devastating disease characterized by excessive proliferation of the Pulmonary Arterial Smooth Muscle Cells (PASMCs). Studies suggest that PAH and cancers share an apoptosis-resistant state featuring excessive cell proliferation. The proliferation of cancer cells is mediated by increased expression of Enhancer of Zeste Homolog 2 (EZH2), a mammalian histone methyltransferase that contributes to the epigenetic silencing of target genes. However, the role of EZH2 in PAH has not been studied. In this study, it is hypothesized that EZH2 could play a role in the proliferation of PASMCs.In the present study, the expression patterns of EZH2 were investigated in normal and hypertensive mouse PASMCs. The effects of EZH2 overexpression on the proliferation of human PASMCs were tested. PASMCs were transfected with EZH2 or GFP using nucleofector system. After transfection, the cells were incubated for 48 hours at 37°C. Proliferation and cell cycle analysis were performed using flow cytometry. Apoptosis of PASMCs was determined using annexin V staining and cell migration was tested by wound healing assay.EZH2 protein expression in mouse PASMCs were correlated with an increase in right ventricular systolic pressure and Right Ventricular Hypertrophy (RVH). The overexpression of EZH2 in human PASMCs enhances proliferation, migration, and decrease in the rate of apoptosis when compared to GFP-transfected cells. In the G2/M phase of the EZH2 transfected cells, there was a 3.5 fold increase in proliferation, while there was a significant decrease in the rate of apoptosis of PASMCs, when compared to control.These findings suggest that EZH2 plays a role in the migration and proliferation of PASMCs, which is a major hallmark in PAH. It also suggests that EZH2 could play a role in the development of PAH and can serve as a potential target for new therapies for PAH
Transcriptome profiling of the rice blast fungus during invasive plant infection and in vitro stresses
<p>Abstract</p> <p>Background</p> <p>Rice blast is the most threatening disease to cultivated rice. <it>Magnaporthe oryzae</it>, its causal agent, is likely to encounter environmental challenges during invasive growth in its host plants that require shifts in gene expression to establish a compatible interaction. Here, we tested the hypothesis that gene expression patterns during <it>in planta </it>invasive growth are similar to <it>in vitro </it>stress conditions, such as nutrient limitation, temperature up shift and oxidative stress, and determined which condition most closely mimicked that of <it>in planta </it>invasive growth. Gene expression data were collected from these <it>in vitro </it>experiments and compared to fungal gene expression during the invasive growth phase at 72 hours post-inoculation in compatible interactions on two grass hosts, rice and barley.</p> <p>Results</p> <p>We identified 4,973 genes that were differentially expressed in at least one of the <it>in planta </it>and <it>in vitro </it>stress conditions when compared to fungal mycelia grown in complete medium, which was used as reference. From those genes, 1,909 showed similar expression patterns between at least one of the <it>in vitro </it>stresses and rice and/or barley. Hierarchical clustering of these 1,909 genes showed three major clusters in which <it>in planta </it>conditions closely grouped with the nutrient starvation conditions. Out of these 1,909 genes, 55 genes and 129 genes were induced and repressed in all treatments, respectively. Functional categorization of the 55 induced genes revealed that most were either related to carbon metabolism, membrane proteins, or were involved in oxidoreduction reactions. The 129 repressed genes showed putative roles in vesicle trafficking, signal transduction, nitrogen metabolism, or molecular transport.</p> <p>Conclusions</p> <p>These findings suggest that <it>M. oryzae </it>is likely primarily coping with nutrient-limited environments at the invasive growth stage 72 hours post-inoculation, and not with oxidative or temperature stresses.</p
Effect of bimodaldistribution in ferritegrainsizes on the tensileproperties of low-carbonsteels
In order to understand the effect of grainsize bimodality on the tensileproperties, low-carbonsteel samples having bimodalferritegrainsizedistributions, with different coarse-grainsizes (15–54 μm), fine-grainsizes (2.4–13.0 μm) and coarse-grain fractions (0.10–0.45) have been tensile tested. Samples having bimodalgrain structures showed lower strength (UTS: 395–744 MPa), better tensile ductility (eu: 8.5–19.4%) and lower YS to UTS ratio (0.63–0.84) than the ultra-fined grained steel (UTS = 900 MPa, eu = 5%, and YS:UTS = 0.93). In case of mixed grain structures, effective grainsize (Deff), numerical average grainsize (Davg) and the average grainsize in the fine-grain regions (Df) showed better correlation with strength (i.e. strength ∝ D−1/2) than the weighted average grainsize (Dwt). Coarse-grainsizes in the range of 15–35 μm and fraction of the coarse-grain regions in the range of 15–35% can be recommended for achieving the best tensile ductility. Measurement of micro-hardness and the change in grain aspect ratios from the coarse- and fine-grain regions indicated that the bimodalgrain structure can be considered as a composite structure, where stress and strain vary between the coarse- and fine-grain regions. Lower nucleation and higher growth of the voids in the carbide-depleted, coarse-grain regions (than carbide-rich, fine-grain regions) allow higher plastic deformation till fracture and improve the total-elongation of the steel
Bi(OTf)3 as mild, efficient and cost-effective catalyst for the alkylation of N-heterocycles with epoxides
Epoxides undergo smooth ring opening with N-heterocyclic compounds such as indoles and pyrroles in the presence of a catalytic amount of bismuth triflate under mild conditions to produce C-alkylated indole and pyrrole derivatives in high yields with a high regioselectivity. Imidazole and benzotriazole affords N-alkylated products under identical conditions