Cu-doped inorganic semiconductors with concomitant optical properties have garnered enormous research interest in the last two decades. However, uncertainties over the origin of Cu emission, its ...oxidation state, resemblance with trap state emission, position of Cu d-state, emission spectral width, and moreover understanding of the doping mechanism restricted the wide development of the synthetic methodology for high-quality Cu-doped nanocrystals. It has been shown recently that the emission from Cu-doped semiconductor nanocrystals can span over a wide spectral window and could be a potential color tunable dispersed nanocrystal emitter. Herein, we report the size and composition of variable Cu-doped ZnS/Zn1−x Cd x S zinc-blende (ZB) surface alloyed nanocrystals with intense, stable, and tunable emission covering the blue to red end of the visible spectrum. Further, the Cu dopant emission is distinguished from trap state emission, and the composition variable spectral broadening has been justified on the account of a different environment around the Cu ions in the host lattice. Whereas some findings are in agreement with past reports, several new physical insights presented here would help the community for an in-depth mechanistic study on Cu doping. Moreover, these doped nanocrystal emitters can be a promising candidate for application ranging from optoelectronics to bio-labeling.
We have analyzed identified particle transverse momentum spectra in high multiplicity events in pp collisions at LHC energies s=0.9–13 TeV published by the CMS Collaboration using the color string ...percolation model (CSPM). In CSPM color strings are formed after the collision, which decay into new strings through color neutral q−q¯ pairs production. With the increase in the pp collisions energy number of strings grow and randomly statistically overlap producing higher string tension of the composite strings. The net color in the overlap string area is a vector sum of the randomly oriented strings. The Schwinger color string breaking mechanism produces these color neutral q−q¯ pairs at time ∼1 fm/c, which subsequently hadronize. The initial temperature is extracted both in low and high multiplicity events.The shear viscosity to entropy density ratios η/s are obtained as a function of temperature. For the higher multiplicity events at s=7 and 13 TeV the initial temperature is above the universal hadronization temperature and is consistent with the creation of deconfined matter. The η/s is similar to that in Au+Au collisions at sNN=200 GeV. The small value of η/s above the universal hadronization temperature suggested that the matter is a strongly coupled quark gluon plasma. In these small systems it can be argued that the thermalization is a consequence of the quantum tunneling through the event horizon introduced by the quarks confined in the colliding nucleons and their deceleration due to string formation, in analogy to the Hawking-Unruh radiation which provides a stochastic approach to equilibrium. The disk areas cluster on the nucleon transverse collision area. At the 2D percolation threshold a macroscopic spanning cluster suddenly occurs at the temperature Ti=Th, representing a small connected droplet of q−q¯ pairs, the quark-gluon plasma (QGP). Th is the universal hadronization temperature ∼167.7 MeV. The collision energy dependent buildup of the 2D percolation clusters defines the temperature range 159±9 MeV of the crossover transition between hadrons to the QGP in reasonable agreement with the lattice quantum chromodynamics (LQCD) pseudocritical temperature value of 155±9 MeV. Color string percolation model is the new initial stage paradigm for the study of the high density matter produced in pp and A+A collisions. With CSPM we can directly explore the thermodynamics of the QGP above the universal hadronization temperature.
This article assesses the effects of formal meńtoring on workplace networks. It also provides conceptual clarity and empirical evidence on expected gender differences in the effects of such programs. ...Qualitative interviews with 40 past participants in a formal mentoring program at a software laboratory in Beijing, China, provide insight into the core mechanisms by which such programs produce network change: access to organizational elites, participation in semiformal foci, enhanced social skills, and legitimacy-enhancing signals. These mechanisms are theorized to lead to an expansion in protégés' networks, relative to those of non-participants in formal mentoring. Legitimacy-enhancing signals are theorized to enable female protégés to derive greater network benefit from formal mentoring than their male counterparts. Empirical support for these propositions comes from a longitudinal quasi-experiment involving 75 employees who experienced the treatment of formal mentoring and 64 employees in a matched control group. A second empirical strategy, which exploits exogenous variation in the timing of treatment and enables a comparison of the post-program networks of one treated group to the pre-program networks of another treated group, provides corroborating support. These findings contribute to research on the efficacy of formal mentoring, gender and workplace networks, and the cumulative advantage or disadvantage that can arise from network change.
Caspase-8 activation can be triggered by death receptor-mediated formation of the death-inducing signaling complex (DISC) and by the inflammasome adaptor ASC. Caspase-8 assembles with FADD at the ...DISC and with ASC at the inflammasome through its tandem death effector domain (tDED), which is regulated by the tDED-containing cellular inhibitor cFLIP and the viral inhibitor MC159. Here we present the caspase-8 tDED filament structure determined by cryoelectron microscopy. Extensive assembly interfaces not predicted by the previously proposed linear DED chain model were uncovered, and were further confirmed by structure-based mutagenesis in filament formation in vitro and Fas-induced apoptosis and ASC-mediated caspase-8 recruitment in cells. Structurally, the two DEDs in caspase-8 use quasi-equivalent contacts to enable assembly. Using the tDED filament structure as a template, structural analyses reveal the interaction surfaces between FADD and caspase-8 and the distinct mechanisms of regulation by cFLIP and MC159 through comingling and capping, respectively.
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•Caspase-8 tDED assembles into filaments through quasi-equivalent contacts•The assembly of caspase-8 filaments is nucleated by the upstream Fas/FADD complex•cFLIP tDED also forms filaments, which interact with caspase-8 by comingling•MC159 inhibits caspase-8 filament assembly by a unique capping mechanism
How caspase-8 is activated has been a long-standing question. Fu et al. show that its tDED forms filaments using quasi-equivalent interactions. Cryo-EM structure of the filament reveals mechanisms of caspase-8 activation and its regulation by cFLIP and MC159.
Ohmic heating (OH) is a novel method of heating various food materials efficiently, instantly and volumetrically. The quick and volumetric heating during OH results in efficient enzyme and microbial ...inactivation. Thus, OH can be used as an efficient alternative to the conventional thermal processing method.
OH has been applied to various food materials, which include fruits and vegetable products, milk, meat, seafood etc. Inactivation of quality degrading enzymes and spoilage causing microbes to a desired safe level is the prime objective of thermal processing of food, which can be easily achieved by OH process. In addition to the thermal effects, OH also has some non-thermal effects on microbial and enzyme activities due to the presence of electric current during heating. However, these non-thermal effects of OH are possible only in enzymes containing prosthetic metallic groups such as, Cu in PPO, Fe in lipoxygenase, Zn and Mg in alkaline phosphatase.
Various models such as First order, Bi-phasic and Lumry–Eyring mechanism have been reported in literature for the enzyme inactivation by OH. Enzyme inactivation has been found to increase with increasing electric field strength (V/cm) during the OH process. The spoilage causing microorganisms can also be inactivated efficiently by OH as compared to conventional heating. Higher voltage gradients enhance the non-thermal effects of OH on microbial reduction by resulting in the higher electroporation. The frequency of the electric current also plays an important role in microbial reduction. Various components present in food such as fat, sugar and acid content affect the electrochemical properties of food material, thus affect the performance of OH in reducing the microbial load.
•Enzyme and microbial inactivation during conventional and OH have been compared.•Non thermal effects of OH on the enzymes and microbial activity have been explained.•Effects of composition and ingredients on enzyme and microbial inactivation during OH.•Electroporation due to OH causes higher microbial cell damage than thermal treatment.
Historical archives refer to often recurring earthquakes along the Eastern Himalaya for which geological evidence is lacking, raising the question of whether these events ruptured the surface or ...remained blind, and how do they contribute to the seismic budget of the region, which is home to millions of inhabitants. We report a first mega trench excavation at Himebasti village, Arunachal Pradesh, India, and analyze it with modern geological techniques. The study includes twenty-one radiocarbon dates to limit the timing of displacement after 1445 CE, suggesting that the area was devastated in the 1697 CE event, known as Sadiya Earthquake, with a dip-slip displacement of 15.3 ± 4.6 m. Intensity prediction equations and scaling laws for earthquake rupture size allow us to constraints a magnitude of Mw 7.7-8.1 and a minimum rupture length of ~ 100 km for the 1697 CE earthquake.
•The kiwifruits are highly susceptible to spoilage microorganisms.•Ultrasonic intensity has strong influence on surface microbial reduction.•Ultrasound treatment increases the post-harvest shelf life ...of kiwifruits.
This study reports the optimization of ultrasonic treatment combined with sodium hypochlorite (NaOCl) solution on kiwifruit (Actinidia deliciosa) to evaluate its effect on microbial population, respiration rate and its textural quality. Response surface methodology (RSM) based on four factors three level central composite design was applied to investigate the effects of process variables on ultrasonic treatment. Four independent variables include ultrasonic intensity (184–368W/cm2), temperature (25–40°C), treatment time (8–15min) and concentration of the solvent (30–60ppm) were considered for this study. According to RSM analysis, the optimal treatment parameters obtained were ultrasonic intensity (368W/cm2), temperature (25°C), treatment time (8min) and concentration of the solvent (30ppm). Microbial population, respiration rate and some quality parameters were compared with NaOCl treated kiwifruits. An ultrasound combined with NaOCl was found to be the most effective treatment in inhibiting the microbial growth (bacteria, yeast and mold) and preserving the quality of kiwifruits, and these results suggest that the ultrasound treatment may provide an alternative for extending the shelf life of whole kiwifruit, maintains the quality of fresh cut kiwifruits and further increases the shelf life of chitosan coated fresh cut kiwifruit.
Insulin‐like growth factor 1 (IGF‐1) mediates the generation of reactive oxygen species (ROS) and the activation of growth promoting signaling pathways. Histone deacetylases (HDACs) regulate gene ...transcription by deacetylating lysine residues in histone and nonhistone proteins and a heightened HDAC activation, notably of HDAC5, is associated with vascular disorders, such as atherosclerosis. Although the contribution of IGF‐1 in these pathologies is well documented, its role in HDAC phosphorylation and activation remains unexplored. Here, we examined the effect of IGF‐1 on HDAC5 phosphorylation in vascular smooth muscle cells (VSMCs) and identified the signaling pathways involved in controlling HDAC5 phosphorylation and nuclear export. Treatment of A10 VSMCs with IGF‐1 enhanced HDAC5 phosphorylation. Blockade of the IGF‐1 receptor tyrosine kinase (TK) activity with the specific pharmacological inhibitor, AG1024, significantly inhibited IGF‐1‐induced HDAC5 phosphorylation, whereas the epidermal growth factor receptor (EGFR) TK antagonist, AG1478, had no effect. Inhibition of the mitogen‐activated protein kinase pathway with U0126, SP600125, or SB203580, did not affect HDAC5 phosphorylation, whereas two inhibitors of the phosphoinositide 3‐kinase (PI3K)/AKT pathways, wortmannin and SC66, almost completely attenuated IGF‐1‐induced responses as confirmed by immunoblotting of phospho‐HDAC5 and by small interfering RNA (siRNA)‐induced AKT silencing. Moreover, the NAD(P)H oxidase (Nox) inhibitor, diphenyleneiodonium (DPI), and Nox4 siRNA, attenuated IGF‐1‐induced phosphorylation of HDAC5 and AKT. The HDAC5 phosphorylation resulted in its nuclear export, which was reversed by SC66 and DPI. Our results indicate that IGF‐1‐induced phosphorylation and nuclear export of HDAC5 involve Nox4‐dependent ROS generation and PI3K/AKT signaling pathways.
Our data have revealed a previously unidentified role of the phosphoinositide 3‐kinase (PI3K)/AKT pathway in inducing histone deacetylase 5 (HDAC5) phosphorylation and nuclear export in response to insulin‐like growth factor 1 (IGF‐1). Because nuclear exclusion of HDAC has been implicated in enhanced migration and proliferation of vascular smooth muscle cells (VSMCs) by altered expression of genes associated with cell cycle regulation, it may be suggested that NADPH oxidase 4 (Nox4)‐generated reactive oxygen species (ROS) via AKT‐induced phosphorylation of HDAC5 may constitute a potential mechanism to trigger a transcriptional program leading to exaggerated migration and proliferation of VSMCs resulting in vascular remodelling.
Nonmonotonic variation with collision energy (sqrts_{NN}) of the moments of the net-baryon number distribution in heavy-ion collisions, related to the correlation length and the susceptibilities of ...the system, is suggested as a signature for the quantum chromodynamics critical point. We report the first evidence of a nonmonotonic variation in the kurtosis times variance of the net-proton number (proxy for net-baryon number) distribution as a function of sqrts_{NN} with 3.1 σ significance for head-on (central) gold-on-gold (Au+Au) collisions measured solenoidal tracker at Relativistic Heavy Ion Collider. Data in noncentral Au+Au collisions and models of heavy-ion collisions without a critical point show a monotonic variation as a function of sqrts_{NN}.
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