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Multiparticle correlations and higher order harmonics in pPb collisions at root s(NN)=8.16 TeV
No full textThe elliptic and higher-order azimuthal anisotropy Fourier harmonics (v(n)) are obtained for pPb collisions at root s(NN) = 8.16 TeV over a wide range of event multiplicities based on multiparticle correlations. The data were collected by the CMS experiment during the 2016 LHC run. A sample of peripheral PbPb collisions at root s(NN) = 5.02 TeV covering a similar range of event multiplicities to the pPb results is also analyzed for comparison. The ratios of different harmonic moments are obtained for both v(2) and v(3) with high precision, which allows a direct comparison to theoretical predictions assuming a hydrodynamic evolution of the created medium with initial-state density fluctuations, particularly probing the non-Gaussian nature of initial-state fluctuations in small collision systems. The presented results provide crucial insights into the origin of collective long-range correlations observed in small collision systems
Insights into physiological roles of unique metabolites released from Plasmodium-infected RBCs and their potential as clinical biomarkers for malaria
No full textPlasmodium sp. are obligate intracellular parasites that derive most of their nutrients from their host meaning the metabolic circuitry of both are intricately linked. We employed untargeted, global mass spectrometry to identify metabolites present in the culture supernatants of P. falciparum-infected red blood cells synchronized at ring, trophozoite and schizont developmental stages. This revealed a temporal regulation in release of a distinct set of metabolites compared with supernatants of non-infected red blood cells. Of the distinct metabolites we identified pipecolic acid to be abundantly present in parasite lysate, infected red blood cells and infected culture supernatant. Further, we performed targeted metabolomics to quantify pipecolic acid concentrations in both the supernatants of red blood cells infected with P. falciparum, as well as in the plasma and infected RBCs of P. berghei-infected mice. Measurable and significant hyperpipecolatemia suggest that pipecolic acid has the potential to be a diagnostic marker for malaria. © 2019, The Author(s)
Tuning the fluorescence behavior of liquid crystal molecules containing Schiff-base: Effect of solvent polarity
No full textWe report the influence of intermolecular and intramolecular hydrogen bonding on the excited state proton transfer (ESPT) emission behavior of two bent core liquid crystal (BLC) molecules, C 54 H 63 NO 9 (BLC3) and C 60 H 75 NO 9 (BLC4), having a Schiff-base and two long alkyl chains at its two ends. Fluorescence spectra of these BLC molecules dispersed in different solvents show dual emission (at � 365 nm and �425 nm) from the keto and enol tautomers. We observed that the population of these keto and enol tautomers and the corresponding intensities of fluorescence emission are strongly influenced by the solvent polarity. In protic solvents, formation of intermolecular hydrogen bond with the Schiff-base of the BLC molecules is highly favoured than the intramolecular hydrogen bonding. This intermolecular hydrogen bonding drastically reduces the population of the keto tautomers in the excited state, resulting in enhanced enol fluoroscence band along with a weak keto emission band. The observed intensity of the enol fluorescence band is the highest for the most studied polar solvent (methanol). On the other hand, in aprotic solvents, the intramolecular hydrogen bonding is highly favoured, which leads to the formation of keto tautomers in the excited state. Hence, an intense keto emission band is observed for the aprotic solvents along with a weak enol emission band. From the time resolved fluorescence studies we observed a longer life time for the keto band than that for the enol band. This is also related to the delayed emission associated with the vibrational bands resulting from the bulky alkyl chains attached to the ends of the BLC molecules. © 2019 Elsevier B.V
A manganese oxide nanozyme prevents the oxidative damage of biomolecules without affecting the endogenous antioxidant system
No full textBiocompatible nanoparticles with an intrinsic ability to mimic the cellular antioxidant enzymes are potential candidates for the development of new therapeutics for various oxidative stress related disorders. However, the understanding of the interaction and the mechanistic crosstalk between the nanoparticles and the cellular biomolecules is limited. Here we show that the multienzyme mimic manganese(ii,iii) oxide, Mn 3 O 4 , in nanoform (Mp) rescues the cells from oxidative damage induced by reactive oxygen species (ROS). The nanoparticles provide remarkable protection to biomolecules against the ROS-mediated protein oxidation, lipid peroxidation and DNA damage. Interestingly, the endogenous antioxidant machinery remains unaltered in the presence of these nanozymes, indicating the small molecule targeting of these nanoparticles in the cellular redox modulation. This study delineates the possible mechanism by which the nanoparticles provide protection to the cells against the adverse effects of oxidative stress. Based on our observation, we suggest that the multienzyme mimic Mn 3 O 4 nanoparticles possess great potential in suppressing the oxidative stress-mediated pathophysiological conditions under which the antioxidant system is overwhelmed. This journal is © The Royal Society of Chemistry
2D-MoS 2 photocatalyzed cross dehydrogenative coupling reaction synchronized with hydrogen evolution reaction
No full textThe chemically exfoliated 2D-MoS 2 has a mixture of 1T (metallic) and 2H (semiconducting) phases. It has shown a considerably good catalytic activity for hydrogen evolution reaction (HER), proceeding via electrochemical as well as photochemical pathways. Experimentalists have utilized triethanolamine or other sacrificial donors along with Eosin Y as a photosensitizer. But the potential of this reaction has not yet been fully explored as the sacrificial donor is wasted in the oxidation process. The oxidation cycle of this process can be used in many organic transformation(s). Herein, we report the use of the oxidative cycle for efficient cross dehydrogenative coupling (CDC) reaction with tetrahydroisoquinoline and indole substrates as well as their derivatives, parallel to HER. The reaction results in good to excellent yield of the corresponding product under visible light irradiation at room temperature. The mechanistic investigation has also been carried out. This study is a potential example of how to fully harness the oxidation and reduction cycles of many semiconductor based photocatalysts. © 2019 The Royal Society of Chemistry
Hydrodynamic moraine-breach modeling and outburst flood routing - A hazard assessment of the South Lhonak lake, Sikkim
No full textThe presence of glacial lakes in the Himalaya makes it a potential mountain hazard, as catastrophic failure of such waterbodies may lead to high-magnitude glacial lake outburst flood (GLOF) events that can cause significant damage to the low-lying areas. The present study evaluates the hazard potential of the South Lhonak lake located in the state of Sikkim, using both one and two-dimensional hydrodynamic modeling approaches. Different breach parameters were calculated based on the lake bathymetry and moraine dimensions. The worst-case GLOF scenario is revealed during an overtopping failure of the moraine, producing a peak flood of 6064.6 m 3 s �1 and releasing a total water volume of 25.7 � 10 6 m 3 . The GLOF hydrograph is routed to calculate peak flood (m 3 s �1 ), inundation depth (m) and flow velocity (ms �1 ) along the main flow channel. The interaction of the flood wave with a major topographic obstruction located 15.6 km downstream of the lake, shows a significant reduction of the flow energy leading to a minimization of the South Lhonak GLOF impact. The flood wave reaches the nearest town Lachen, located at a distance of 46 km downstream from the lake, at 3 h 38 min after the initiation of the breach, with a peak flood of 3928.16 m 3 s �1 and a maximum flow velocity of 13.6 ms �1 . At Chungthang town, located at a distance of 62.35 km from South Lhonak lake, the flood wave potentially inundates settlements along the bank of the flow channel, where a peak flood of 3828.08 m 3 s �1 is reached after 4 h of the initial dam breach event. The study also incorporates modeling of a framework to propose a potential flood remediation measure of the South Lhonak lake GLOF by demonstrating the effect of a lateral inline structure along the flow channel, to check the flow of the potential flood wave. © 2019 Elsevier B.V
Self-Powered, Broad Band, and Ultrafast InGaN-Based Photodetector
No full textA self-powered, broad band and ultrafast photodetector based on n + -InGaN/AlN/n-Si(111) heterostructure is demonstrated. Si-doped (n + type) InGaN epilayer was grown by plasma-assisted molecular beam epitaxy on a 100 nm thick AlN template on an n-type Si(111) substrate. The n + -InGaN/AlN/n-Si(111) devices exhibit excellent self-powered photoresponse under UV-visible (300-800 nm) light illumination. The maximum response of this self-powered photodetector is observed at 580 nm for low-intensity irradiance (0.1 mW/cm 2 ), owing to the deep donor states present near the InGaN/AlN interface. It shows a responsivity of 9.64 A/W with rise and fall times of 19.9 and 21.4 μs, respectively. A relation between the open circuit voltage and the responsivity has been realized
A feedback loop between microRNA 155 (miR-155), programmed cell death 4, and activation protein 1 modulates the expression of miR-155 and tumorigenesis in tongue cancer
No full textMicroRNA 155 (miR-155) is an oncomir, generated as a noncoding RNA from the BIC gene whose promoter activity is mainly controlled via activation protein 1 (AP-1) and NF-B transcription factors. We found that the expression levels of miR-155 and programmed cell death 4 (Pdcd4) exhibit inverse relationships in tongue cancer cells (SAS and AWL) and tumor tissues compared to their relationships in normal FBM cells and normal tongue tissues, respectively. In silico and in vitro studies with the 3= untranslated region (UTR) of Pdcd4 via luciferase reporter assays, quantitative PCR (qPCR), and Western blotting showed that miR-155 directly targets Pdcd4 mRNA and blocks its expression. Ectopic expression of Pdcd4 or knockdown of miR-155 in tongue cancer cells predominantly reduces AP-1-dependent transcriptional activity of the BIC promoter and decreases miR-155 expression. In this study, we demonstrate that miR-155 expression is modulated by a feedback loop between Pdcd4, AP-1, and miR-155 which results in enhanced expression of miR-155 with a consequent progression of tongue tumorigenesis. Further, miR-155 knockdown increases apoptosis, arrests the cell cycle, regresses tumor size in xenograft nude mice, and reduces cell viability and colony formation in soft-agar and clonogenic assays. Thus, the restoration of Pdcd4 levels by the use of molecular manipulation such as using a miR-155 sponge has an essential role in the therapeutic intervention of cancers, including tongue cancer
DNN Based Speech Enhancement for Unseen Noises Using Monte Carlo Dropout
No full textIn this work, we propose the use of dropout as a Bayesian estimator for increasing the generalizability of a deep neural network (DNN) for speech enhancement. By using Monte Carlo (MC) dropout, we explore whether the DNN can accomplish better enhancement in unseen noisy conditions. Two DNNs are trained on speech corrupted with five different noises at three SNRs, one using conventional dropout and other with MC dropout and tested on speech with unseen noises. Speech samples are obtained from the TIMIT database and noises from NOISEX-92. In another experiment, we train five DNN models separately on speech corrupted with five different noises, at three SNRs. The model precision estimated using MC dropout is used as a proxy for squared error to dynamically select the best of the DNN models based on their performance on each frame of test data. The first set of experiments aims at improving the performance of an existing DNN with conventional dropout for unseen noises, by replacing the conventional dropout with MC dropout. The second set of experiments aims at finding an optimal way of choosing the best DNN model for de-noising when multiple noise-specific DNN models are available, for unseen noisy conditions. © 2018 IEEE
A Novel Exoplanetary Habitability Score via Particle Swarm Optimization of CES Production Functions
No full textThe search for life has two goals essentially: looking for planets with Earth-like conditions (Earth similarity) and looking for the possibility of life in some form (habitability). Determining habitability from exoplanet data requires that determining parameters are collectively considered before coming up with a conclusion as no single factor alone contributes to it. Our proposed models, would serve as an indicator while looking for new habitable worlds, if computed with precision and efficiency. The models are of the type constrained optimization, multivariate, convex but may suffer from curvature violation and premature convergence impacting desired habitability scores. We mitigate the problem by proposing modified Particle Swarm optimization (PSO) to tackle constraints and ensuring global optima. In the process, a python library to tackle such problems has been created. © 2018 IEEE