Low‐temperature conductivity of epitaxial ZnSe in the impurity band regime

Low‐temperature conductivity of several samples of ZnSe grown by molecular‐beam epitaxy has been measured. The data indicate that for samples with carrier concentration below or near Nc, metal insulator transition, the conductivity obeys σ=σ0 exp[−(T0/T)s] at low temperatures with s=1/2. This behavior is a characteristic of variable‐range hopping conduction in the presence of a Coulomb gap. © 1994 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70255/2/APPLAB-65-20-2568-1.pd

Metabolic Dependencies in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDA) is a highly lethal cancer with a long-term survival rate under 10%. Available cytotoxic chemotherapies have significant side effects, and only marginal therapeutic efficacy. FDA approved drugs currently used against PDA target DNA metabolism and DNA integrity. However, alternative metabolic targets beyond DNA may prove to be much more effective. PDA cells are forced to live within a particularly severe microenvironment characterized by relative hypovascularity, hypoxia, and nutrient deprivation. Thus, PDA cells must possess biochemical flexibility in order to adapt to austere conditions. A better understanding of the metabolic dependencies required by PDA to survive and thrive within a harsh metabolic milieu could reveal specific metabolic vulnerabilities. These molecular requirements can then be targeted therapeutically, and would likely be associated with a clinically significant therapeutic window since the normal tissue is so well-perfused with an abundant nutrient supply. Recent work has uncovered a number of promising therapeutic targets in the metabolic domain, and clinicians are already translating some of these discoveries to the clinic. In this review, we highlight mitochondria metabolism, non-canonical nutrient acquisition pathways (macropinocytosis and use of pancreatic stellate cell-derived alanine), and redox homeostasis as compelling therapeutic opportunities in the metabolic domain

The Effect of Energy Transportation of High-Energy Electrons on the Electromagnetic Instability

The energy transportation of High-energy electrons to the compressed fuel and study of affected factors on it are the most important issues in fast ignition method. In this research, regarding the role of Weibel instability in process modulation and possible impacts of electron and plasma beam velocity to reach higher energy yields, the effect of temporal variation of particle distribution in the presence of laser electric fields on growth andcondition of Weibel instability in beam-plasma medium were investigated in the form of a classic system without any Coulombic collision between the particles and magnetic fields. The results show that the time-dependent drift velocity leads to a decrease the growth rate of the Weibel when energy transportation of energetic particles to the fusion plasma systems increases

Acute Haemodynamic Changes During Haemodialysis Do Not Exacerbate Gut Hyperpermeability

© 2019 The Author(s)Introduction: The gastrointestinal tract is a potential source of inflammation in dialysis patients. In-vitro studies suggest breakdown of the gut barrier in uraemia leading to increased intestinal permeability and it is hypothesised that haemodialysis exacerbates this problem due to mesenteric ischemia induced by blood volume changes during treatment. Method: The effect of haemodialysis on intestinal permeability was studied in ten haemodialysis patients and compared with five controls. Intestinal permeability was assessed by measuring the differential absorption of four orally administered sugar probes which provides an index of small and whole bowel permeability. A multi-sugar solution (containing lactulose, rhamnose, sucralose and erythritol) was orally administered after an overnight fast. Plasma levels of all sugar probes were measured hourly for 10hrs post-administration. In haemodialysis patients, the procedure was carried out twice – once on a non-dialysis day and once immediately after haemodialysis. Results: Area under curve (AUC) for lactulose: rhamnose (L:R) ratio and sucralose: erythritol (S:E) ratio was similar post-dialysis and on non-dialysis days. AUC for L:R was higher in haemodialysis patients compared to controls (0.071 vs. 0.034,p=0.001), AUC for S:E ratio was not significantly different. Levels of lactulose, sucralose and erythritol were elevated and retained for longer in haemodialysis patients compared to controls due to dependence of sugars on kidney function for clearance. Conclusion: We found no significant acute changes in intestinal permeability in relation to the haemodialysis procedure. Valid comparison of intestinal permeability between controls and haemodialysis patients was not possible due to the strong influence of kidney function on sugar levels.Peer reviewedFinal Published versio

Exact thermoelastic analysis of a thick cylindrical functionally graded material shell under unsteady heating using first order shear deformation theory

In this article, a new analytical formulation is presented for axisymmetric thick-walled FGM cylinder with power-law variation in mechanical and thermal properties under transient heating using first order shear deformation theory. Equilibrium equations are derived by virtual work principles and energy method. The unsteady heat conduction equation is solved using the method of separation of variables, generalized Bessel functions and an Eigen-function method. Validation of the analytical solutions is conducted with a finite element method (FEM). The effects of time on stress and displacement distribution are studied in detail. The numerical values used in this study are selected based on earlier studies. The influence of effect of transient heat transfer on heterogeneous thick-walled cylinder elasticity is clearly demonstrated. In particular the significant influence of time and heterogenous constant on radial displacement, hoop stress and temperature distributions is computed. The study is relevant to rocket chamber thermo-mechanics, propulsion duct thermophysical design, industrial thermal storage systems etc

A Cretaceous foraminiferal assemblage from West of Kerman area (Iran)

Abstrac

Triggered qutrits for Quantum Communication protocols

A general protocol in Quantum Information and Communication relies in the ability of producing, transmitting and reconstructing, in general, qunits. In this letter we show for the first time the experimental implementation of these three basic steps on a pure state in a three dimensional space, by means of the orbital angular momentum of the photons. The reconstruction of the qutrit is performed with tomographic techniques and a Maximum-Likelihood estimation method. In this way we also demonstrate that we can perform any transformation in the three dimensional space

Facies analysis and paleoenvironmental reconstruction of Upper Cretaceous sequences in the eastern Para-Tethys Basin, NW Iran

Upper Cretaceous mixed carbonate-siliciclastic sequences are among the most important targets for hydrocarbon exploration in the Moghan area, located in the eastern Para-Tethys Basin. Despite of their significance, little is known about their facies characteristics and depositional environments. Detailed facies analysis and paleoenvironmental reconstruction of these sequences have been carried out in eight surface sections. Accordingly, four siliciclastic facies, eight carbonate facies and one volcanic facies have been recognized. Detailed facies descriptions and interpretations, together with the results of facies frequency analysis, standard facies models and Upper Cretaceous depositional models of Para-Tethys Basin, have been integrated and a non-rimmed carbonate platform is presented. This platform was affected by siliciclastic influx, in the form of coastal fan delta and submarine fans in the shallow- to deep-marine parts, respectively. This model is interpreted to be shallower in the central and northeastern parts of the Moghan area. Toward the southeast and southwest, this shallow platform turns into deep marine settings along steep slopes without remarkable marginal barriers

Electromechanical Piezoresistive Sensing in Suspended Graphene Membranes

Monolayer graphene exhibits exceptional electronic and mechanical properties, making it a very promising material for nanoelectromechanical (NEMS) devices. Here, we conclusively demonstrate the piezoresistive effect in graphene in a nano-electromechanical membrane configuration that provides direct electrical readout of pressure to strain transduction. This makes it highly relevant for an important class of nano-electromechanical system (NEMS) transducers. This demonstration is consistent with our simulations and previously reported gauge factors and simulation values. The membrane in our experiment acts as a strain gauge independent of crystallographic orientation and allows for aggressive size scalability. When compared with conventional pressure sensors, the sensors have orders of magnitude higher sensitivity per unit area.Comment: 20 pages, 3 figure