The catalytic activity of graphene oxide supported copper oxide (CuO–GO) has been investigated in Click synthesis of 1,2,3‐triazole derivatives under green reaction conditions. In the context of ...green approach, water is used as solvent under ligand free and aerobic conditions at room temperature, with low catalyst loading (0.2 mol %) while ensuring the recovery and reusability of the catalyst. The catalyst affords excellent selectivity in formation of the desired products in good to excellent yields. Further, the work‐up procedure adopted here is clean and simple, while recycling the organic solvents that one used for work‐up procedure. It is proposed that the functional groups present on the GO surface are effective for preventing the aggregation of the catalytically active copper oxide species during the reaction. Moreover, the excellent performance of CuO–GO nanocomposite is ascribed to the excellent dispersity of the catalyst in water, hydrophilic nature of the GO for the accumulation of organic substrates in water and the “Breslow effect.”
The effect of polyvinylidene fluoride (PVDF) polymer interlayer on the rectifying junction parameters of Au/n-InP Schottky diode has been investigated using current–voltage (I–V) and ...capacitance–voltage (C–V) measurements at room temperature. The calculated barrier heights (BHs) are 0.57eV (I–V), 0.72eV (C–V) and 0.73eV (I–V), 0.88eV (C–V) for the Au/n-InP and Au/PVDF/n-InP Schottky diodes, respectively. Results showed that the BH of the Au/PVDF/n-InP Schottky diode is higher than that of the Au/n-InP Schottky diode, and that the PVDF film increases the effective BH by influencing the space charge region of the n-type InP. The values of the barrier height, ideality factors and series resistance estimated by I–V, Cheung's and Norde methods are compared. Experimental results showed that the interface state density of the Au/PVDF/n-InP Schottky diode is lower than that of the Au/n-InP Schottky diode. Further, the reverse leakage current conduction mechanism is investigated. Schottky emission mechanism is found to dominate the reverse leakage current in the Au/n-InP Schottky diode. However, for the Au/PVDF/n-InP Schottky diode, the Schottky conduction mechanism is found to be dominant in the higher bias region, whereas the Poole–Frenkel conduction is found to be dominant in the lower bias region. Apart from that, the discrepancy between BHs determined from I–V and C–V techniques is explained. Besides, the capacitance–frequency (C–f) and conductance–frequency (G–f) characteristics of the Au/PVDF/n-InP Schottky diode are discussed.
•Electrical properties of Au/polyvinylidene fluoride (PVDF)/n-InP diode are studied.•PVDF interlayer led to increase in the barrier height of Au/n-InP Schottky diodes.•Interface state density of Au/PVDF/n-InP diode is lower compared to Au/n-InP diode.•Current conduction mechanism of Au/n-InP and Au/PVDF/n-InP diodes is investigated.•Frequential capacitance and conductance characteristics of Au/PVDF/n-InP diode
Small heat shock proteins (sHsps) belong to the family of heat shock proteins (Hsps): some are induced in response to multiple stressful events to protect the cells while others are constitutively ...expressed. Until now, it was believed that Hsps, including sHsps, are present inside the cells and perform intracellular functions. Interestingly, several groups recently reported the extracellular presence of Hsps, and sHsps have also been detected in sera/cerebrospinal fluids in various pathological conditions. Secretion into the extracellular milieu during many pathological conditions suggests additional or novel functions of sHsps in addition to their intracellular properties. Extracellular sHsps are implicated in cell-cell communication, activation of immune cells, and promoting anti-inflammatory and anti-platelet responses. Interestingly, exogenous administration of sHsps showed therapeutic effects in multiple disease models implying that extracellular sHsps are beneficial in pathological conditions. sHsps do not possess signal sequence and, hence, are not exported through the classical Endoplasmic reticulum-Golgi complex (ER-Golgi) secretory pathway. Further, export of sHsps is not inhibited by ER-Golgi secretory pathway inhibitors implying the involvement of a nonclassical secretory pathway in sHsp export. In lieu, lysoendosomal and exosomal pathways have been proposed for the export of sHsps. Heat shock protein 27 (Hsp27), αB-crystallin (αBC), and Hsp20 are shown to be exported by exosomes. Exosomes packaged with sHsps have beneficial effects in in vivo disease models. However, secretion mechanisms and therapeutic use of sHsps have not been elucidated in detail. Therefore, this review aimed at highlighting the current understanding of sHsps (Hsp27, αBC, and Hsp20) in the extracellular medium.
The Hippo signaling pathway has a conserved role in growth control and is of fundamental importance during both normal development and oncogenesis. Despite rapid progress in recent years, key steps ...in the pathway remain poorly understood, in part due to the incomplete identification of components. Through a genetic screen, we identified the Drosophila Zyxin family gene, Zyx102 (Zyx), as a component of the Hippo pathway. Zyx positively regulates the Hippo pathway transcriptional co-activator Yorkie, as its loss reduces Yorkie activity and organ growth. Through epistasis tests, we position the requirement for Zyx within the Fat branch of Hippo signaling, downstream of Fat and Dco, and upstream of the Yorkie kinase Warts, and we find that Zyx is required for the influence of Fat on Warts protein levels. Zyx localizes to the sub-apical membrane, with distinctive peaks of accumulation at intercellular vertices. This partially overlaps the membrane localization of the myosin Dachs, which has similar effects on Fat-Hippo signaling. Co-immunoprecipitation experiments show that Zyx can bind to Dachs and that Dachs stimulates binding of Zyx to Warts. We also extend characterization of the Ajuba LIM protein Jub and determine that although Jub and Zyx share C-terminal LIM domains, they regulate Hippo signaling in distinct ways. Our results identify a role for Zyx in the Hippo pathway and suggest a mechanism for the role of Dachs: because Fat regulates the localization of Dachs to the membrane, where it can overlap with Zyx, we propose that the regulated localization of Dachs influences downstream signaling by modulating Zyx-Warts binding. Mammalian Zyxin proteins have been implicated in linking effects of mechanical strain to cell behavior. Our identification of Zyx as a regulator of Hippo signaling thus also raises the possibility that mechanical strain could be linked to the regulation of gene expression and growth through Hippo signaling.
Hypervalent iodine chemistry is a rapidly growing area of research with tremendous impact on synthetic chemistry in the past years. A rich and diverse chemistry is now available for reactions using ...hypervalent iodine reagents, as metal‐free, ecofriendly reagents and the advent of new reactions will be of large benefit to researchers working in the area of selective synthesis. In this review article, we emphasize the usage of hypervalent iodine(III) reagents for metal‐free intramolecular oxidative C–N bond formation/annulation to synthesize wide range of N‐heterocycles in organic synthesis. The functionalization of C–H bonds through the involvement of sp‐, sp2‐, and sp3‐hybridized carbon atoms for cyclizations is discussed in detail.
Hypervalent iodine(III) reagents are valuable oxidants with soft, non‐toxic, and environmentally friendly features. These reagents are successfully applied for the cyclization/annulation through a C–H bond functionalization of sp‐, sp2‐, and sp3‐hybridized carbon atoms. In this review article, the use of hypervalent iodine(III) reagents for metal‐free intramolecular oxidative C–N bond formation reactions to produce the immense array of N‐heterocyclic compounds in synthetic organic chemistry is highlighted.
Lithium batteries are electrochemical devices that are widely used as power sources. This history of their development focuses on the original development of lithium-ion batteries. In particular, we ...highlight the contributions of Professor Michel Armand related to the electrodes and electrolytes for lithium-ion batteries.
The solar thermal power plant is one of the promising renewable energy options to substitute the increasing demand of conventional energy. The cost per kW of solar power is higher and the overall ...efficiency of the system is lower. In the present communication, a comprehensive literature review on the scenario of solar thermal power plants and its up-to-date technologies all over the world is presented. Results of the technical and economical feasibility studies by researchers are reported in brief for further reference. It is observed that the solar thermal power plants have come out of the experimental stage to commercial applications. Case studies of typical 50MW solar thermal power plants in the Indian climatic conditions at locations such as Jodhpur and Delhi is highlighted with the help of techno-economic model. Different solar concentrator technologies (parabolic trough, parabolic dish and central power tower) for solar thermal power plants are compared economically. It has been found that the parabolic dish concentrating solar Stirling engine power plant generate electricity at a lower unit cost than the other two solar technologies considering 30 years lifespan and 10% interest rate on investment.
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