•Efforts are taken to deposit WO3 directly on to glass substrate without assistance of seed layer hydrothermal technique.•2D nanoplates like structure of WO3 were synthesized via simple route.•The 2D ...nanoplates of WO3 exhibited excellent and highly selective gas response ∼10 for 5ppm.•The new synthesis route and sensing behavior of as synthesized WO3 nanoplates revealed a promising candidate for fabricating low-consumption gas sensors.
Gas sensors based on a chemiresistive metal oxide semiconductor are widely used including nitrogen dioxide (NO2) at a moderate temperature. In this work efforts are taken to fabricate NO2 gas sensor using thin films of tungsten oxide (WO3) grown directly on to a soda-lime glass substrate without assistance of any seed layer by a simple and a facile hydrothermal technique. As per our knowledge, the deposition of nanostructured WO3 thin films without assistance of any seed layer on the glass substrate was rarely reported. The WO3 thin film samples were synthesized at various deposition times ranging from 3h to 7h and were characterized by X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, UV–vis spectroscopy and Brunauer-Emmett-Teller techniques. The surface morphological and structural characterization showed the two dimensional (2D) nanoplate-like structure of as synthesized WO3 thin films with plate thickness ranging from 90 to 150nm and had an orthorhombic structure, respectively. Moreover, the 2D nanoplates of WO3 exhibited a gas response ∼10 for 5ppm for toxic NO2 gas at relatively low operating temperature. The new synthesis route and sensing behavior of as synthesized WO3 nanoplates revealed a promising candidate for the fabrication of the cost effective gas sensors.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The generation of hydrogen and oxygen from the photocatalytic water splitting reaction under visible light is a promisingly renewable and clean source for H2 fuel. The transition metal oxide ...semiconductors (e.g. TiO2, WO3, ZnO, and ZrO2) are have been widely used as photocatalysts for the hydrogen generation. Because of safety, low cost, chemical inertness, photostability and other characteristics (bandgap, corrosion resistance, thermal and environmental stability), TiO2 is considered as a most potential catalyst of the semiconductors being investigated and developed. However, the extensive applications of TiO2 are hampered by its inability to exploit the solar energy of visible region. Other demerits are lesser absorbance under visible light, and recombination of photogenerated electron-hole pairs. In this review, we focus on the all the possible reactions taking place at the catalyst during photo-induced H2 from water splitting reaction, which is green and promising technology. Various parameter affecting the photocatalytic water splitting reactions are also studied. Predominantly, this review is focussed on bandgap engineering of TiO2 such as the upward shift of valence band and downward shift of conduction bands by doping process to extend its light absorption property into the visible region. Furthermore, the recent advances in this direction including various new strategies of synthesis, multiple doping, hetero-junction, functionalization, perspective and future opportunities of non-metals-doped TiO2-based nanostructured photocatalysts for various photocatalytic applications such as efficient hydrogen production, air purification and CO2 reduction to valuable chemicals have been discussed.
•Non-metals-doped TiO2 nanostructures for enhanced photocatalysis were reviewed.•Various parameters were discussed to improve visible-light catalytic activity.•Non-metals doped catalysts have potential for efficient hydrogen production.•Other applications such as air purification and CO2 reduction were discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Transition metal phosphides are a new class of materials that have attracted enormous attention as a potential electrode for supercapacitors (SCs) compared to metal oxides/hydroxides and metal ...sulfides due to their strong redox-active behaviour, good electrical conductivity, layered structure, low cost, and high chemical and thermal stability. Recently, several efforts have been made to develop nickel phosphides (Ni
x
P
y
) (NPs) for high-performance SCs. The electrochemical properties of NPs can be easily tuned by several innovative approaches, such as heteroatom doping, defect engineering, and developing a hollow architecture. The prospects of NPs as a positive electrode in hybrid SCs are summarized to understand the material's practical relevance. Finally, the challenges and perspectives are provided for the development of high-performance NPs for SCs. The thorough elucidation of the structure-property-performance relationship offers a guide for developing NP-based next-generation energy-storage devices.
Transition metal phosphides are a new class of materials that have attracted enormous attention as a potential electrode for supercapacitors (SCs).
Abstract The inverse relationship between the linear increase in skewness parameter s and the domain’s width of the order of skewness n plays a vital role in both critical beam radius and propagation ...dynamics of skew-cosh-Gaussian (skew-chG) laser beams. The interplay between the skewness parameter s and the order of skewness n is explored analytically and graphically in the current study to unveil the complexity of the propagation dynamics of the skew-chG laser beam. Naturally, the intensity’s complexity considerably affects the dielectric constant of the medium. Basically, the nonlinearity in the dielectric function of collisional plasma is attributed to the non-uniform heating of energy carriers along the wavefront of the laser beam, which becomes important and is used in the current study. By following Akhmanov’s parabolic wave equation approach under Wentzel–Kramers–Brillouin and paraxial approximations, the nonlinear differential equations are set up for the beam width parameters f 1 and f 2 and solved numerically. The present work analytically investigates the domains of the order n of skew-chG laser beams for a given set of skewness parameter s to investigate their effects on the self-focusing and defocusing of skew-chG laser beams. The critical curve also gets affected significantly due to the choice of domains for n . Finally, the numerical results are presented in the form of graphs and discussed in this study.
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•Ultrasound was applied to intensify the DES based extraction of curcuminoids.•Effect of different processing parameters on UA-DES based extraction was optimized.•Curcuminoids ...recovered from UA-DES extract using anti-solvent precipitation.•Comparison study based on yield, time, solvent requirement and temperature was done.•Energy consumption and cost for different extraction approaches were calculated.
The use of deep eutectic solvents (DESs) as a new extraction medium is a step towards the development of green and sustainable technology. In the present study, nine DESs based on choline chloride acids, alcohols, and sugar were screened to study the extraction of curcuminoids from Curcuma longa L. Choline chloride and lactic acid DES at 1:1 M ratio gave the maximum extent of extraction. Further, DES based extraction was intensified using ultrasound. The impact of various process parameters such as % (v/v) water in DES, % (w/v) solid loading, particle size, ultrasound power intensity, and pulse mode operation of ultrasound was studied. The maximum curcuminoids yield of 77.13 mg/g was achieved using ultrasound assisted DES (UA-DES) based extraction in 20% water content DES at 5% solid loading and 0.355 mm particle size with 70.8 W/cm2 power intensity and 60% (6 sec ON and 4 sec OFF) duty cycle at 30 ± 2 °C in 20 min of irradiation time. Kinetics of UA-DES extraction was explained using Peleg’s model and concluded that it is compatible with the experimental data. Additionally, anti-solvent (water) precipitation technique was applied, which resulted in 41.97% recovery of curcuminoids with 82.22% purity from UA-DES extract in 8 h of incubation at 0 °C. The comparison was made between conventional Soxhlet, batch, DES and UA-DES based processes on the basis of yield, time, solvent requirement, temperature, energy consumption, and process cost. The developed UA-DES based extraction can be an efficient, cost effective, and green alternative to conventional solvent extraction for curcuminoids.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Indoles represent an important structural class in medicinal chemistry with broad spectrum of biological activities. The synthesis of indoles, therefore, has attracted enormous attention from ...synthetic chemists. Microwave methods for the preparation of indole analogs have been developed to speed up the synthesis, therefore, microwave assisted organic synthesis (MAOS) in controlled conditions is an invaluable technique for medicinal chemistry. In this review, indole forming classical reactions such as Fischer, Madelung, Bischler-Mohlau, Batcho-Leimgruber, Hemetsberger-Knittel, Graebe-Ullmann, Diels-Alder and Wittig type reactions using microwave radiation has been summarized. In addition, metal mediated cyclizations along with solid phase synthesis of indoles have been discussed.
Recently, the nanostructured metal oxides are widely attracted for resistive switching memory devices. In this work, nanostructured ZnO thin films were deposited via simple and cost-effective spray ...pyrolysis technique (SPT) onto a glass/FTO substrates at 450 °C by varying the solution quantity such as 40, 80, and 120 ml. The structural, morphological, and compositional properties of the deposited ZnO thin films were investigated using XRD, FESEM, AFM and EDAX characterizations. All the deposited ZnO samples showed crystalline nature with nanoflakes-like morphology. The bipolar resistive switching properties of the Al/ZnO/FTO fabricated memristive devices and its mechanism were investigated. The fabricated memristive device showed two-valued charge–flux relation which confirms non-ideal memristor devices. The data retention property of memristive devices was examined by measuring the low-resistance state (LRS) and high-resistance state (HRS) for every 10 s and it can retain data up to 10
4
s. The ZnO-based memristive device possesses good non-volatile memory properties with reliable device performance that can be advantageous for light-responsive memory, synaptic, sensor devices, etc.
Graphical abstract
Synthesis of nanostructured ZnO thin films by spray pyrolysis technique for resistive switching applications.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Emerging evidence from the current outbreak of Zika virus (ZIKV) indicates a strong causal link between Zika and microcephaly. To investigate how ZIKV infection leads to microcephaly, we used human ...embryonic stem cell-derived cerebral organoids to recapitulate early stage, first trimester fetal brain development. Here we show that a prototype strain of ZIKV, MR766, efficiently infects organoids and causes a decrease in overall organoid size that correlates with the kinetics of viral copy number. The innate immune receptor Toll-like-Receptor 3 (TLR3) was upregulated after ZIKV infection of human organoids and mouse neurospheres and TLR3 inhibition reduced the phenotypic effects of ZIKV infection. Pathway analysis of gene expression changes during TLR3 activation highlighted 41 genes also related to neuronal development, suggesting a mechanistic connection to disrupted neurogenesis. Together, therefore, our findings identify a link between ZIKV-mediated TLR3 activation, perturbed cell fate, and a reduction in organoid volume reminiscent of microcephaly.
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•hESC-derived cerebral organoids model fetal brain development•Zika virus infects neural progenitor cells in organoid and neurosphere models•Zika virus activates Toll-like receptor 3 in cerebral organoids•TLR3 triggers apoptosis and attenuates neurogenesis
Dang et al. show that Zika virus (ZIKV) attenuates growth in cerebral organoids from human embryonic stem cells by targeting neural progenitors. ZIKV activates the TLR3-mediated innate immune response, leading to dysregulation of a network of genes involved in neurogenesis, axon guidance, apoptosis, and differentiation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The process of measurement can modify the state of a quantum system and its subsequent evolution. Here, we demonstrate the control of quantum tunneling in an ultracold lattice gas by the measurement ...backaction imposed by the act of imaging the atoms, i.e., light scattering. By varying the rate of light scattering from the atomic ensemble, we show the crossover from the weak measurement regime, where position measurements have little influence on tunneling dynamics, to the strong measurement regime, where measurement-induced localization causes a large suppression of tunneling--a manifestation of the quantum Zeno effect. Our study realizes an experimental demonstration of the paradigmatic Heisenberg microscope and sheds light on the implications of measurement on the coherent evolution of a quantum system.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Present study aimed to assess effect of pre-treatment with
seed extract and its bioactive molecule(s) on NMDAR and Tau protein gene expression in cerebral ischemic rodent model. Methanol extract of
...seeds was characterized by HPLC, and β-sitosterol was isolated by flash chromatography.
studies to observe the effect of pre-treatment (28 days) with methanol extract of
seed and β-sitosterol on the unilateral cerebral ischemic rat model. Cerebral ischemia induced by left common carotid artery occlusion (LCCAO) for 75 min (on day 29) followed by reperfusion for 12 h. Rats (
= 48) divided into four groups. GroupI (control,Untreated + LCCAO)-No pre-treatment + cerebral ischemia; GroupII(β-sitosterol + Sham)-pre-treatment with β-sitosterol, 10 mg/kg/day + sham-operated; GroupIII(β-sitosterol + LCCAO)-pre-treatment with β-sitosterol, 10 mg/kg/day + cerebral ischemia; GroupIV(methanol extract + LCCAO)-pre-treatment with methanol extract of
seeds, 50 mg/kg/day + cerebral ischemia. Neurological deficit score was assessed just before sacrifice. Experimental animals were sacrificed after 12 h reperfusion. Brain histopathology was performed. Gene expression of NMDAR and Tau protein of left cerebral hemisphere (occluded side) was performed by RT-PCR. Results revealed that the neurological deficit score was lower in groups III and IV compared to group I. NMDAR and tau protein mRNA expression in left cerebral hemisphere were upregulated in Group I, downregulated in groups III and IV. Histopathology of left cerebral hemisphere (occluded side) in Group I showed features of ischemic brain damage. Groups III and IV, left cerebral hemisphere showed less ischemic damage compared GroupI. Right cerebral hemisphere showed no areas of ischemia-induced brain changes. Pre-treatment with β-sitosterol and methanol extract of
seeds may reduce ischemic brain injury following unilateral common carotid artery occlusion in rats.
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