1,523 research outputs found
Spectral variability in NGC 1042 ULX1
We report X-ray spectral variability in an ultraluminous X-ray source NGC
1042 ULX1, using archival XMM-Newton and recent NuSTAR observations. In
long-term evolution, the source has shown a trend of variation in spectral
hardness. The variability in different XMM-Newton observations is prominent
above keV. Cool thermal disk component with a characteristic
temperature of keV manifests that the spectral state of NGC 1042
ULX1 in all epochs is similar to that of the ultraluminous state sources. An
apparent anti-correlation between luminosity and powerlaw index demonstrates
that the source becomes spectrally harder when it is in a brighter state. That
is conceivably related to variation in accretion rate, strength of
comptonization, wind/outflow in the system or a manifestation of varying disk
occultation. Typical hard ultraluminous type spectra indicate that NGC 1042
ULX1 is a low inclination system in general. Spectral properties suggest that,
like many other ULXs which show spectral curvature around keV, NGC
1042 ULX1 could be another stellar-mass super-Eddington accretor.Comment: 9 pages, 5 figures, accepted for publication in MNRA
Genetics of asthma: current research paving the way for development of personalized drugs
Asthma is a complex genetic disorder involving the interplay between various environmental and genetic factors. In this review, efforts have been made to provide information on the recent advances in these areas and to discuss the future perspective of research in the area of developing personalized drugs using pharmacogenomic approach. Atopic asthma is found to be strongly familial, however the mode of inheritance is controversial. A large number of studies have been carried out and a number of candidate genes have been identified. In addition, a number of chromosomal regions have been identified using genome-wide scans, which might contain important unknown genes. It has been shown in studies carried out in different populations that the genetic predisposition varies with ethnicity. In other words, genes that are associated with asthma in one population may not be associated with asthma in another population. In addition to the involvement of multiple genes, gene-gene interactions play a significant role in asthma. The importance of environmental factors in asthma is beyond doubt. However, it remains controversial whether a cleaner environment or increased pollution is a trigger for asthma. Despite the increasing prevalence of the disorder, only a limited number of therapeutic modalities are available for the treatment. A number of novel therapeutic targets have been identified and drugs are being developed for better efficacy with less side-effects. With the rapid progress in the identification of genes involved in various ethnic populations combined with the availability in future of well-targeted drugs, it will be possible to have appropriate medicine as per the genetic make-up of an individual
Is Diabetes Pre-coded in the Brain? Role of Hypothalamus, Addiction Network and Social Cognition
The hypothalamus, the master regulator of circadian rhythm, in association with peripheral clocks, play crucial roles in glucose metabolism. Impairment in cerebral sensing, uptake and processing of glucose has been suggested in various animal and human diabetic models. Diabetes Mellitus has been largely superseded by the discovery of insulin and insulin resistance. Expanding horizons of knowledge of the roles of the hypothalamus in glucose metabolism and the overlapping neural pathways of sugar addictionwith other classically described substance and behavioral addictions networks have again thrown some light on the cerebral theory of DM pathogenesis
Investigation of ZnO nanoparticles for their applications in wastewater treatment and antimicrobial activity
The photocatalytic as well as the antimicrobial activity of the synthesized ZnO nanoparticles (ZnO-NPs) through solution based approach have been presented in this study. ZnO-NPs have been characterised by thermogravimetry/differential thermal analysis (TG/DTA), ultraviolet-visible (UV–Vis), Fourier transform infrared (FTIR) and Raman spectroscopy. Raman studies confirm that it has stable wurtzite structure. FTIR spectrum confirms the Zn–O band at ~460 cm-1. Optical studies reveal that the optical band gap value increases with increasing annealing temperature. The photocatalytic activity of the ZnO-NPs has been evaluated for removal of pollutants from wastewater by measuring COD and BOD. Results show that ZnO-NPs are capable of working efficiently for waste water treatment. ZnO-NPs also demonstrate antimicrobial activity against gram-positive and gram-negative bacterial strains
Fatty Acid Concentration and Phase Transitions Modulate Aβ Aggregation Pathways
Aggregation of amyloid β (Aβ) peptides is a significant event that underpins Alzheimer disease (AD) pathology. Aβ aggregates, especially the low-molecular weight oligomers, are the primary toxic agents in AD and hence, there is increasing interest in understanding their formation and behavior. Aggregation is a nucleation-dependent process in which the pre-nucleation events are dominated by Aβ homotypic interactions. Dynamic flux and stochasticity during pre-nucleation renders the reactions susceptible to perturbations by other molecules. In this context, we investigate the heterotypic interactions between Aβ and fatty acids (FAs) by two independent tool-sets such as reduced order modelling (ROM) and ensemble kinetic simulation (EKS). We observe that FAs influence Aβ dynamics distinctively in three broadly-defined FAconcentration regimes containing non-micellar, pseudo-micellar or micellar phases. While the non-micellar phase promotes on-pathway fibrils, pseudo-micellar and micellar phases promote predominantly off-pathway oligomers, albeit via subtly different mechanisms. Importantly off-pathway oligomers saturate within a limited molecular size, and likely with a different overall conformation than those formed along the on-pathway, suggesting the generation of distinct conformeric strains of Aβ, which may have profound phenotypic outcomes. Our results validate previous experimental observations and provide insights into potential influence of biological interfaces in modulating Aβ aggregation pathways
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