64 research outputs found
Rapid thermal annealing: An efficient method to improve the electrical properties of tellurium compensated Interfacial Misfit GaSb/GaAs heterostructures
The effect of thermal annealing on Te compensated Interfacial Misfit GaSb/GaAs heterostructures is investigated by using two different thermal annealing procedures, namely rapid thermal annealing and furnace annealing. The electrical properties of the devices are studied by using Current–Voltage, Capacitance–Voltage and Deep Level Transient Spectroscopy techniques. It is observed that rapid thermal annealing treatment is superior in terms of improvement of the electrical characteristics compared to furnace annealing treatment. The lowest leakage current and defect concentration are obtained when rapid thermal annealing is employed
Identification of differentially methylated CpG Sites in fibroblasts from Keloid Scars
As a part of an abnormal healing process of dermal injuries and irritation, keloid scars arise on the skin as benign fibroproliferative tumors. Although the etiology of keloid scarring remains unsettled, considerable recent evidence suggested that keloidogenesis may be driven by epigenetic changes, particularly, DNA methylation. Therefore, genome-wide scanning of methylated cytosine-phosphoguanine (CpG) sites in extracted DNA from 12 keloid scar fibroblasts (KF) and 12 control skin fibroblasts (CF) (six normal skin fibroblasts and six normotrophic fibroblasts) was conducted using the Illumina Human Methylation 450K BeadChip in two replicates for each sample. Comparing KF and CF used a Linear Models for Microarray Data (Limma) model revealed 100,000 differentially methylated (DM) CpG sites, 20,695 of which were found to be hypomethylated and 79,305 were hypermethylated. The top DM CpG sites were associated with TNKS2, FAM45B, LOC723972, GAS7, RHBDD2 and CAMKK1. Subsequently, the most functionally enriched genes with the top 100 DM CpG sites were significantly (p ≤ 0.05) associated with SH2 domain binding, regulation of transcription, DNA-templated, nucleus, positive regulation of protein targeting to mitochondrion, nucleoplasm, Swr1 complex, histone exchange, and cellular response to organic substance. In addition, NLK, CAMKK1, LPAR2, CASP1, and NHS showed to be the most common regulators in the signaling network analysis. Taken together, these findings shed light on the methylation status of keloids that could be implicated in the underlying mechanism of keloid scars formation and remission
Probiotic-Based bacteriocin: Immunity supplementation against viruses. An updated review
Viral infections are a major cause of severe, fatal diseases worldwide. Recently, these infections have increased due to demanding contextual circumstances, such as environmental changes, increased migration of people and product distribution, rapid demographic changes, and outbreaks of novel viruses, including the COVID-19 outbreak. Internal variables that influence viral immunity have received attention along with these external causes to avert such novel viral outbreaks. The gastrointestinal microbiome (GIM), particularly the present probiotics, plays a vital role in the host immune system by mediating host protective immunity and acting as an immune regulator. Bacteriocins possess numerous health benefits and exhibit antagonistic activity against enteric pathogens and immunobiotics, thereby inhibiting viral infections. Moreover, disrupting the homeostasis of the GIM/host immune system negatively affects viral immunity. The interactions between bacteriocins and infectious viruses, particularly in COVID-19, through improved host immunity and physiology are complex and have not yet been studied, although several studies have proven that bacteriocins influence the outcomes of viral infections. However, the complex transmission to the affected sites and siRNA defense against nuclease digestion lead to challenging clinical trials. Additionally, bacteriocins are well known for their biofunctional properties and underlying mechanisms in the treatment of bacterial and fungal infections. However, few studies have shown the role of probiotics-derived bacteriocin against viral infections. Thus, based on the results of the previous studies, this review lays out a road map for future studies on bacteriocins for treating viral infections
A promoter effect on hydrodeoxygenation reactions of oleic acid by zeolite beta catalysts
In this study, various metal-modified zeolite beta-based catalysts such as La(10)zeo(90), Co(10)zeo(90), Fe(10)zeo(90), Mg(10)zeo(90), Mn(10)zeo(90) and Zn(10)zeo(90) were investigated in the hydrodeoxygenation (HDO) of oleic acid (OA) to produce renewable diesel. The La(10)zeo(90) catalyst showed a conversion of OA up to 99 % with 83 % C15 and C17 selectivity after the reaction at 350 â—¦C for 2 h under 4 MPa H2 pressure. The superior activity of La(10)zeo(90) was attributed to the synergistic interaction between La-Si-Al, a sufficient amount of weak+ medium acid sites and excellent textural properties (large pore diameter). Larger pore diameter of La(10)zeo(90) is highly desirable as it will generate greater diffusion of bulky molecules, thereby improving the accessibility of the reactant and hence excellent catalytic activity. The vacuum distillation was used to purify the crude liquid product (CLP), producing high-quality diesel fractions mainly comprising C14, C15, and C17 fractions
Temporal variations of O3 and NOx in the urban background atmosphere of the coastal city Jeddah, Saudi Arabia
Whole-genome sequencing reveals host factors underlying critical COVID-19
Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease
Some problems in algebraic topology Polynomial algebras over the Steenrod algebras
SIGLEAvailable from British Library Document Supply Centre- DSC:DX93967 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Computer assisted tracking of university student writing in English as a foreign language
The study tracked development along university levels in writing in English as a foreign language of students of two disciplines: English Language and Literature, and Computer Science.Informed by the cognitive process theory of writing, other theoretical accounts of development in writing and findings of relevant literature, the study set out to test hypothesized development in fluency, revision behaviour, writers? awareness and concerns and text quality in the writing of university students. Moreover, the study aimed to find out if students from the two majors demonstrate different developmental patterns in terms of these variables; and if variation in text quality can be related to writing process and awareness.The study utilized a computer logging program (ScriptLog) as the main recording, observing and playback research tool; elicited responses to immediate recall questions; and obtained independent text assessment. It also employed stimulated recall procedure to get a closer look at a small proportion of individual writing sessions.Quantitative data analysis revealed that along the university levels English majors demonstrated systematic development in their writing process and product, with progressively increased fluency, higher-level and more global revision orientation, and better awareness of the demands of task and audience. They also exhibited considerable and consistent improvement in text quality. Computer Science students, on the other hand, displayed a different pattern. In their fourth level there was a notable increase in the rate of production and the proportion of conceptual revisions, but a significant decrease in text quality compared with their three-semester juniors. In their eighth semester, they demonstrated improvement but remained in a lesser position than their English-major peers in fluency measures and text quality. These findings assert the significance of formal L2 knowledge in assisting automatic access to the mental linguistic repertoire and reducing concerns over local and surface-level linguistic details; and they stress the importance of continued formal facilitation of L2.In addition, a number of participants attended individual writing sessions wherein their writing activity was followed by stimulated recall interviews. A close investigation of participants? reports of their writing strategies and concerns asserts the trends found in the quantitative analysis. However the qualitative inquiry offers more insight into the development of university students. It appears that the tertiary academic experience has in the long run benefited both groups of writers. Senior participants of both majors were able to take authority of their texts. They acted less at surface and local levels and more at conceptual and global levels, moving information around and changing larger chunks of text in order to minimize ambiguity and respond to the demands of audience. They showed consideration and utilization of content knowledge they had acquired in their subject area
New regularity criteria for the 3D hall-MHD equations
We prove some regularity criteria for smooth solutions of the three-dimensional incompressible Hall-magnetohydrodynamic equations involving only two components of the velocity and magnetic fields. © Instytut Matematyczny PAN, 2018
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