Search

The development of an efficient and stable non-noble metal catalyst to replace noble metal catalyst for hydrogen evolution reaction (HER) is still a challenge. Herein, we report one-step hydrothermal method to synthesis binary hybrid material composed of MoS 2 /CoS 2 heterostructure (HS) supported on reduced graphene oxide (rGO). The coexistence of HS and rGO exhibit lower overpotential towards the HER activity with superior structural stability comparing to MoS 2 , CoS 2 and MoS 2 /CoS 2 under acidic condition. The MoS 2 /CoS 2 @rGO yielded a low overpotential of −152 mV at cathodic current density −10 mAcm−2 compared to MoS 2 , CoS 2 and MoS 2 /CoS 2 with values of −322 mV, −537 mV and −238 mV. Also, a low Tafel slope value of MoS 2 /CoS 2 @rGO (65 mVdec−1) reflects its superior performance compared to other as-synthesized catalysts. The superior activity of MoS 2 /CoS 2 @rGO attributed by conductive support of rGO and strong interaction between HS and water molecule. The avenues of active sites were triggered due to the formation of HS and electrical conductivity enhancement occurred due to the presence of carbon nanostructure, which proves that further engineering of the catalyst can reduce the overpotential drastically. [Display omitted] • MoS 2 /CoS 2 @rGO as hydrogen evolving electrocatalysts in acidic medium. • Heterostructure consist of CoS 2 nanoparticle bonded with MoS 2 nanosheet with even distribution over rGO. • MoS 2 /CoS 2 @rGO exhibited higher HER compared to standalone MoS 2 , CoS 2. • The strong interface between MoS 2 and CoS 2 along rGO made the material potential towards HER. [ABSTRACT FROM AUTHOR]

The oxygen evolution reaction (OER) is a bottleneck in overall water splitting due to the involvement of the four-electron process and requires a high overpotential. This hinders the stability and durability of electrocatalysts over a longer period. Herein, we report flower-like NiCo 2 O 4 decorated on carbon nanostructures synthesized using a one-pot wet chemical method as an OER electrocatalyst in an alkaline medium. The catalytic activities were characterized by various electrochemical measurements including linear sweep voltammetry (LSV), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and turnover frequency (TOF). 90 % NiCo 2 O 4 @rGO/ f -MWCNT demonstrated a higher OER activity compared to stand-alone NiCo 2 O 4 , 90 % NiCo 2 O 4 @rGO, 90 % NiCo 2 O 4 @ f -MWCNT and 80 % NiCo 2 O 4 @rGO/ f -MWCNT. [Display omitted] • NiCo 2 O 4 @NCHy (NCO@NCHy) as oxygen-evolving electrocatalysts in an alkaline medium. • Flower-like pattern distributed onto the surface of nanocarbon hybrid. • The overpotential of the NiCo 2 O 4 @NCHy was 287 mV at a current density of 10 mA/cm2. • NiCo 2 O 4 @NCHy exhibited higher OER compared to NCO and NCO@other carbon nanostructures. • The strong interface between NCO along NCHy made the material potential towards OER. [ABSTRACT FROM AUTHOR]

The unique structure of a natural nucleic acid, calf thymus DNA, which can provide an appropriate scaffold for an efficient cascaded energy transfer among organic chromophores, has been used for the generation of bright and pure white light on UV light excitation. Two most commonly used DNA stains, 4′,6-diamidino-2-phenylindole (DAPI) and ethidium bromide (EB) have been used as a part of the donor-acceptor pairs. We have judiciously selected 10-anthracene-10-yl-3-methylbenzothiazol-3-ium chloride (AnMBTZ), an ultrafast molecular rotor, to act as a bridge between DNA bound DAPI and EB for the cascaded flow of energy. The unique molecular rotor properties of AnMBTZ and its exceptional binding ability with natural DNA help to form a distinct tri-chromophoric system in DNA template which can produce bright and pure white light on UV excitation. Detailed flow of energy from photoexcited DAPI to EB via AnMBTZ has been explored using steady state and time-resolved emission spectroscopy. Further, unique binding nature of AnMBTZ with DNA molecules has been used to modulate the colour of the emission from the present tri-chromophoric system by external stimuli, like salt and temperature. Such unique stimuli responsive multi-chromophoric system in a bio-template has great potential for different lightening applications. [ABSTRACT FROM AUTHOR]

Background & Aims Esophageal adenocarcinoma (EAC) is resistant to standard chemoradiation treatments, and few targeted therapies are available. We used large-scale tissue profiling and pharmacogenetic analyses to identify deregulated signaling pathways in EAC tissues that might be targeted to slow tumor growth or progression. Methods We collected 397 biopsy specimens from patients with EAC and nonmalignant Barrett's esophagus (BE), with or without dysplasia. We performed RNA-sequencing analyses and used systems biology approaches to identify pathways that are differentially activated in EAC vs nonmalignant dysplastic tissues; pathway activities were confirmed with immunohistochemistry and quantitative real-time polymerase chain reaction analyses of signaling components in patient tissue samples. Human EAC (FLO-1 and EsoAd1), dysplastic BE (CP-B, CP-C, CP-D), and nondysplastic BE (CP-A) cells were incubated with pharmacologic inhibitors or transfected with small interfering RNAs. We measured effects on proliferation, colony formation, migration, and/or growth of xenograft tumors in nude mice. Results Comparisons of EAC vs nondysplastic BE tissues showed hyperactivation of transforming growth factor-β (TGFB) and/or Jun N-terminal kinase (JNK) signaling pathways in more than 80% of EAC samples. Immunohistochemical analyses showed increased nuclear localization of phosphorylated JUN and SMAD proteins in EAC tumor tissues compared with nonmalignant tissues. Genes regulated by the TGFB and JNK pathway were overexpressed specifically in EAC and dysplastic BE. Pharmacologic inhibition or knockdown of TGFB or JNK signaling components in EAC cells (FLO-1 or EsoAd1) significantly reduced cell proliferation, colony formation, cell migration, and/or growth of xenograft tumors in mice in a SMAD4-independent manner. Inhibition of the TGFB pathway in BE cell lines reduced the proliferation of dysplastic, but not nondysplastic, cells. Conclusions In a transcriptome analysis of EAC and nondysplastic BE tissues, we found the TGFB and JNK signaling pathways to be hyperactivated in EACs and the genes regulated by these pathways to be overexpressed in EAC and dysplastic BE. Inhibiting these pathways in EAC cells reduces their proliferation, migration, and formation of xenograft tumors. Strategies to block the TGFB and JNK signaling pathways might be developed for treatment of EAC. Graphical abstract [ABSTRACT FROM AUTHOR]

We report a facile, one pot solvothermal route to prepare ultrathin molybdenum disulfide supported on nanocarbon hybrid (MoS 2 @NCHy) network with varied mass loading of MoS 2 (20 wt%, 40 wt% and 60 wt%) for catalyzing hydrogen evolution reaction (HER). A large current density of −451 mAcm −2 at an overpotential of −480 mV vs. RHE, proves 40 wt% MoS 2 @NCHy/GCE nanocomposite as a highly HER active catalytic material. This value was found to be 50 times, 6 times and 2.5 times higher compared to MoS 2 /GCE (−8 mAcm −2 ), 20 wt% MoS 2 @NCHy/GCE (−75 mAcm −2 ) and 60 wt% MoS 2 @NCHy/GCE (−180 mAcm −2 ) respectively. Meanwhile, η 10 (overpotential required to attain a current density of −10 mAcm −2 ) is −186 mV for 40 wt% MoS 2 @NCHy/GCE, which is much lower to MoS 2 /GCE (−498 mV), NCHy/GCE (−334 mV), 20 wt% MoS 2 @NCHy/GCE (−264 mV) and 60 wt% MoS 2 @NCHy/GCE (−204 mV). The overall activity of the catalyst was manifested by the least overpotential, η 10  = −186 mV vs. RHE, Tafel slope of 53 mVdec −1 and exchange current density ( j 0 ) of 6.3 × 10 −2  mAcm −2 . The superior performance of 40 wt% MoS 2 @NCHy should be attributed to the highly conductive and porous support of three dimensional NCHy architecture as well as the enlarged interlayer spacing of MoS 2 . This study paves a new paradigm to exploit the synergistic effect of MoS 2 and NCHy resulting in strong electronic coupling for enhancement in the HER activity. [ABSTRACT FROM AUTHOR]

In this article, optical soliton solutions of the time fractional Biswas–Milovic equation obtained by employing Shehu Adomian Decomposition Method (SADM). We study the projected model in terms of fractional order employing Caputo (C), Caputo–Fabrizio (CF), and Atangana–Baleanu in Caputo sense (ABC) derivatives to validate and demonstrate the competency of proposed techniques. Convergence and uniqueness of the proposed techniques are analysed. The numerical simulations are carried out and compared with the existing methods. Moreover, We depicted the 2-D,3-D and contour graphs to illustrate the behaviour of obtained solutions. • Optical soliton solutions of nonlinear time fractional Biswas–Milovic equation studied. • The fractional derivative considered with singular and non-singular kernels. • Convergence and uniqueness presented. • Proposed technique compared with those existing methods. • Solution phenomena presented graphically. [ABSTRACT FROM AUTHOR]

The short wave direct Aerosol Radiative Forcing (ARF) at a semi urban coastal location near Chennai (12.81 °N, 80.03 °E, ∼45 m amsl), a mega city on the east coast of India has been estimated for all the four seasons in the year 2013 using the SBDART (Santa Barbara Discrete ordinate Atmospheric Radiative Transfer) model. As inputs to this model, measured aerosol parameters together with modeled aerosol and atmospheric parameters are used. The ARF in the atmosphere is found to be higher in the pre-monsoon and winter seasons compared to the other seasons whereas at the surface, it is found to be higher in the south-west (SW) monsoon and winter seasons. The estimated ARF values are compared with those reported over other locations in India. The effect of Relative Humidity on ARF has been investigated for the first time in the present study. It is found that the ARF increases with increasing RH in the SW monsoon and winter seasons. An unique feature of the present study is the comparison of the net surface short wave fluxes estimated from the model (SBDART) and measured fluxes using CNR 4 net radiometer. This comparison between the estimated and measured fluxes showed good agreement, providing a ‘closure’ for the estimates. [ABSTRACT FROM AUTHOR]

The emission properties of Thioflavin-T (ThT), a cationic molecular rotor, have been investigated in two fluoroalkylphosphate ([FAP]) anion based ionic liquids, namely, 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate and 1-(2-hydroxyethyl)-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate, over a wide temperature range. The micro-viscosities of ionic liquids around ThT, measured from the emission quantum yield, are found to be quite different from their bulk viscosities. The temperature dependence of the viscosity and the emission quantum yield reveals that, despite the very low shear viscosity of these ILs, the non-radiative torsional relaxation has a strong dependence on the free volume of these [FAP] anion based ILs. [ABSTRACT FROM AUTHOR]

The possibility of intermolecular photoinduced ET (PET) is investigated in a novel donor–acceptor (D–A) system consisting of zinc tetraphenylporphyrin (ZnTPP) as donor and 2-nitrofluorene (2NF) as acceptor upon photoexcitation of the former moieties in polar solvent acetonitrile (ACN). The observed values (7.23 × 10 9 L/(mol s) and 7.04 × 10 9 L/(mol s)) of the fluorescence quenching rate constant from steady state and time-resolved data, respectively, are in good agreement with that (5.65 × 10 9 L/(mol s)) obtained from Marcus theory. Excited state absorption (ESA) from the S 2 state of Soret excited ZnTPP to higher electronic states gives rise to broad transient absorption spectra in 560–700 nm region. Presence of 2NF leads to a faster decay (up to 100 ps time delay) of the ESA signal of ZnTPP at a probe wavelength of 620 nm. This indicates ultrafast ET from the S 2 state (zero vibrational level) as well as the higher vibrational levels of the S 1 state of ZnTPP to 2NF. Moreover, transient absorption kinetics at longer time delays (up to 7 ns) at a probe wavelength of 620 nm show the formation of a charge separated state due to ET from the S 1 state (zero vibrational level) of the Soret excited ZnTPP to 2NF. [ABSTRACT FROM AUTHOR]

The aggregation of proteins into the amyloid fibrils is mainly responsible for several neurological diseases. Knowledge of dynamics in amyloid fibril is very essential to understand its biological activity. Although, the effects of environment like pH, ionic strength, temperature, etc. on the fibril have been studied extensively, studies on the dynamics of amyloid fibril and the role of water in fibril are scarce. In this article, we have reported the results on the excited state dynamics of amyloid fibrils formed by a well-known blood plasma protein, human serum albumin (HSA), at neutral pH. The sole tryptophan residue, W214, has been used as the intrinsic fluorescent probe to monitor its excited state dynamics. Steady-state and time-resolved fluorescence data suggests that the W214 becomes more closer to the quencher amino acid residues in the fibrillar phase than in the native protein. From detailed time-resolved emission measurements, it is shown that despite having a more ordered structure, the water molecules around W214 in amyloid fibril is more labile than that in the native protein. Fluorescence depolarization studies also indicate that the W214 residue is located in a relatively more flexible region of the ordered amyloid fibril than that in the native protein. [ABSTRACT FROM AUTHOR]

Benzothiazole based ultrafast molecular rotor, Thioflavin T (ThT), is a well known fluorescence sensor for nucleic acids. Thus, the knowledge of mode of interaction between ThT and DNA is very important for efficient utilization of such fluorescence sensors. In the present article, we have reported detail studies on the mode of interaction between ThT and a natural DNA using steady-state and femtosecond time-resolved transient emission techniques. Detail steady-state studies show that ThT binds strongly with natural DNA and causes a large change in its spectroscopic properties. Femtosecond transient emission studies show a substantial decrease in the torsional motion in the excited state of ThT bound to DNA molecules, indicating a strong interaction between them. It is observed that ThT binds to DNA through two modes of interaction. Studies with salt indicate that large fraction of ThT binds to DNA by electrostatic interaction, whereas, viscosity and resonance energy transfer studies indicate the intercalation of ThT with DNA molecules. [ABSTRACT FROM AUTHOR]

The scattering and absorption components of Aerosol Optical Depth (AOD) over a semi-urban coastal location (12.81°N, 80.03°E) near the mega city Chennai in peninsular India are separated using the collocated measurements of Black Carbon concentration and Atmospheric Boundary Layer Height (ABLH) from ERA Interim Reanalysis data assuming that most of the BC is contained and homogeneously mixed in the ABL. It is found that the absorption component to scattering component ratio has a strong seasonal variation with a pronounced maximum in the South West (SW) monsoon season. This is indicative of more effective wet removal of scattering aerosols than absorbing (BC) aerosols. There could also be an effect due to preferential removal of large particles which would have a lower content of BC. The Angstrom wavelength exponent shows a minimum in the SW monsoon season, the minimum being more pronounced for the scattering aerosols implying relative dominance of coarse mode particles. Investigation of the effect of Relative Humidity on scattering and absorption components of AOD revealed that the BC (absorbing) aerosols are non-hydrophilic/not coated with hydrophilic substance. [ABSTRACT FROM AUTHOR]

The possible role of photoinduced electron transfer is investigated in the fluorescence quenching of the donors metallo-octaethylporphyrins (zinc octaethylporphyrin and magnesium octaethylporphyrin) in presence of the acceptor 2-nitrofluorene in polar acetonitrile liquid medium by using steady state and time-resolved techniques at the ambient temperature (300 K). The donors are selectively excited at the Q band (S1 state), where 2-nitrofluorene has negligible absorbance. The observed bimolecular fluorescence quenching rate constants for the present donor--acceptor systems from steady state as well as time-resolved fluorescence quenching data are of the order of 1010 L/(mol s) (less than the diffusion-controlled limit of 1.9 x 1010 L/(mol s)). The moderately negative values of Gibbs free energy change (ΔG°) indicate that photoinduced electron transfer from the metallo-porphyrins to 2-nitrofluorene in acetonitrile solvent is possible upon photoexcitation of the former molecules. Moreover, the fluorescence quenching rates for both the donor--acceptor systems obtained from Marcus theory agree quite well with the observed values from fluorescence quenching measurements (especially time-resolved measurements). [ABSTRACT FROM AUTHOR]

Summary Macrophages can fuse to form osteoclasts in bone or multinucleate giant cells (MGCs) as part of the immune response. We use a systems genetics approach in rat macrophages to unravel their genetic determinants of multinucleation and investigate their role in both bone homeostasis and inflammatory disease. We identify a trans -regulated gene network associated with macrophage multinucleation and Kcnn4 as being the most significantly trans -regulated gene in the network and induced at the onset of fusion. Kcnn4 is required for osteoclast and MGC formation in rodents and humans. Genetic deletion of Kcnn4 reduces macrophage multinucleation through modulation of Ca 2+ signaling, increases bone mass, and improves clinical outcome in arthritis. Pharmacological blockade of Kcnn4 reduces experimental glomerulonephritis. Our data implicate Kcnn4 in macrophage multinucleation, identifying it as a potential therapeutic target for inhibition of bone resorption and chronic inflammation. [ABSTRACT FROM AUTHOR]

Regular measurements of Black Carbon (BC) aerosol mass concentration have been carried out since March 2011 at a tropical location (12.81°N, 80.03°E) adjoining the mega city, Chennai, on the east coast of India for the first time. As this region is influenced by both the South West and North East monsoons, the BC observations at this site assume importance in understanding the overall BC distribution over India. The data collected until August 2012 has been examined for the general and regionally distinctive features. Spectral absorption characteristics reveal that the BC is mainly from fossil fuel based emissions. The BC concentration shows significant diurnal variation only in the North East monsoon and winter seasons with night time concentration considerably higher than the day time concentration. In the other seasons the day–night contrast in BC is not significant. Seasonal variation is rather subdued with a broad maximum during the Northeast monsoon and winter months and a minimum during the southwest monsoon months. The observed diurnal and seasonal variations are examined in the light of local Atmospheric Boundary Layer dynamics and long range transport. For the first time, an inverse relationship has been established between BC and ABL height on a quantitative basis. A distinctive feature of the region is that in all the seasons transport pathways have long continental overpasses which could lead to the suppressed seasonal variation. It is found that the BC over this region shows distinct diurnal and seasonal features compared to those reported for other coastal and inland regions in India. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to prepare and characterize nanometer-sized prodrug (nanoprodrug) of camptothecin. The camptothecin prodrug was synthesized using tetraethylene glycol spacer linked via carbonate bond to camptothecin and via ester bond to α-lipoic acid. The nanoprodrug was prepared through the spontaneous emulsification mechanism using the mixture of camptothecin prodrug and α-tocopherol which served as a structural matrix. The nanoprodrug was activated readily by porcine liver esterase and, with a much slower rate, by hydrolytic degradation. Upon longterm storage, the α-lipoic acid moiety of the camptothecin prodrug gradually oxidized without loss of structural integrity and therapeutic efficacy. Interestingly, the hydrolytic activation was negligible before the oxidation, but was significantly accelerated after the oxidation of the α-lipoic acid moiety, suggesting an oxidative stimuli-responsive activation of the prodrug. The camptothecin nanoprodrug was found to possess significant inhibitory effect on the proliferation of U87-MG glioma cells with an IC50 of 20nM. [ABSTRACT FROM AUTHOR]

Abstract: This paper applies He’s variational iteration method for solving nonlinear singular boundary value problems. The solution process is illustrated and various physically relevant results are obtained. Comparison of the obtained results with exact solutions shows that the method used is an effective and highly promising method for treating various classes of both linear and nonlinear singular boundary value problems. [Copyright &y& Elsevier]

We report a case of QuantiFERON TB-Gold conversion associated to Mycobacterium gordonae in an elderly male from an assisted living facility without known risk factors for tuberculosis. This knowledge of environmental mycobacteria causing positive quantiferon assays is important to avoid unnecessary treatment of false-positive latent tuberculosis, especially in the absence of well-established positive predictive value of quantiferon conversion. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, He’s variational iteration method is applied to solve twelfth-order boundary-value problems. The numerical results obtained with minimum amount of computation are compared with the exact solutions to show the efficiency of the method. The results show that the variational iteration method is of high accuracy, more convenient and efficient for solving high-order boundary-value problems. [Copyright &y& Elsevier]

Amyloid fibrils, an aggregated form of proteins, are responsible for different types of neurological diseases. A constant effort is there for the search of a sensitive and selective probe for amyloid fibrils. Recently, it has been shown that a zwitterionic merocyanine dye, SYPRO Orange, can detect the amyloid fibrils with much higher sensitivity and with much preferred spectroscopic properties than present gold standard amyloid probe, Thioflavin T. In the present work, we have investigated the detailed photophysical properties of SYPRO Orange in different molecular solvents and solvent mixtures with wide range of properties to disentangle the fundamental processes that are responsible for its amyloid sensing activity. It has been shown that SYPRO Orange forms aggregates in water and results in extremely low emission quantum yield. The amyloid induced de-aggregation of SYPRO Orange is primarily responsible for enormous increase in its emission intensity upon binding with amyloid fibrils. Photophysical studies using steady state and time-resolved emission spectroscopy further enlighten us on the role of solvent polarity, solute-solvent H-bonding and solvent viscosity on its sensitivity towards amyloid fibrils. Thus, present results will be quite useful for the use of SYPRO Orange in different other spectroscopic applications. • Detailed photophysics of SYPRO Orange has been investigated to understand its amyloid sensing mechanism. • Steady state and time-resolved emission studies show that SYPRO Orange mainly exist in the aggregated form in water. • The role of amyloid induced de-aggregation is the first step in its amyloid sensing process. • H-bonding, low polarity and high viscosity at amyloid groove is responsible for its high emission yield in fibrils. [ABSTRACT FROM AUTHOR]

Abstract: A complex of three phosphoproteins (P0, P1 and P2) constitutes the stalk region at the GTPase center of the eukaryotic large ribosomal subunit, amongst which the protein P0 plays the most crucial role. Earlier studies have shown the functional complementation of the conditional P0-null mutant of Saccharomyces cerevisiae (W303dGP0) with orthologous P0 genes from fungal and mammalian organisms, but not the protozoan parasite Leishmania infantum. In this paper we show that the PfP0 gene from the protozoan malaria parasite Plasmodium falciparum can functionally complement the conditional P0-null W303dGP0 mutant of S. cerevisiae. Unlike the above orthologous genes, PfP0 gene could also rescue the D67dGP0 strain, which in addition to being a conditional null for ScP0 gene, is a null-mutant for both ScP1α and β genes. However, under stress conditions such as high temperature, salt and osmolarity, PfP0 gene could not rescue D67dGP0 strain. Ribosomes purified from W303dGP0 carrying PfP0 gene did not contain ScP1 protein, indicating a lack of binding of ScP1 to PfP0 protein. Yeast 2-hybrid analysis further confirmed the lack of binding of ScP1 to PfP0 protein. The polymerizing activities of ribosomes with ScP0 or PfP0 protein, in the absence of ScP1 protein, were found to be about 40–45% that of ribosomes with all the yeast P-proteins. In its sensitivity to the inhibitor sordarin, PfP0 was similar to the P0 protein from the fungus Aspergillus fumigatus. These results indicate a closer functional relationship of P. falciparum P0 gene to fungal P0 genes. [Copyright &y& Elsevier]

Patients can be immunocompromised from a diverse range of disease and treatment factors, including malignancies, autoimmune disorders and their treatments, and organ and stem-cell transplantation. Infections are a leading cause of morbidity and mortality in immunocompromised patients, and the disease treatment landscape is continually evolving. Despite being a critical but preventable and curable adverse event, the reporting of infection events in randomised trials lacks sufficient detail while inconsistency of categorisation and definition of infections in observational and registry studies limits comparability and future pooling of data. A core reporting dataset consisting of category, site, severity, organism, and endpoints was developed as a minimum standard for reporting of infection events in immunocompromised patients across study types. Further additional information is recommended depending on study type. The standardised reporting of infectious events and attributable complications in immunocompromised patients will improve diagnostic, treatment, and prevention approaches and facilitate future research in this patient group. [ABSTRACT FROM AUTHOR]