599 research outputs found
Sandwich organization of non-ionic surfactant liquid crystalline phases as induced by large inorganic K4Nb6O17 nanosheets
International audienceWhile keeping its lamellar liquid crystal phase, K4Nb6O17 nanosheets were used as a template to sandwich and stabilize an alkylpoly(ethylene oxide) nonionic surfactant-water system showing a monodomain (lamella) formation within the inorganic niobate sheets that appears to not be depend to the surfactant liquid crystalline state in solution but more its concentration
Phenobarbital Indirectly Activates the Constitutive Active Androstane Receptor (CAR) by Inhibition of Epidermal Growth Factor Receptor Signaling
Phenobarbital is a central nervous system depressant that also indirectly activates nuclear receptor constitutive active androstane receptor (CAR), which promotes drug and energy metabolism, as well as cell growth (and death), in the liver. We found that phenobarbital activated CAR by inhibiting epidermal growth factor receptor (EGFR) signaling. Phenobarbital bound to EGFR and potently inhibited the binding of EGF, which prevented the activation of EGFR. This abrogation of EGFR signaling induced the dephosphorylation of receptor for activated C kinase 1 (RACK1) at Tyr52, which then promoted the dephosphorylation of CAR at Thr38 by the catalytic core subunit of protein phosphatase 2A. The findings demonstrated that the phenobarbital-induced mechanism of CAR dephosphorylation and activation is mediated through its direct interaction with and inhibition of EGFR
Measuring Incineration Plants' Performance using Combined Data Envelopment Analysis, Goal Programming and Mixed Integer Linear Programming
Incineration plants produce heat and power from waste, reduce waste disposal to landfills, and discharge harmful emissions and bottom ash. The objective of the incineration plant is to maximize desirable outputs (heat and power) and minimize undesirable outputs (emissions and bottom ash). Therefore, studying the overall impact of incineration plants in a region so as to maximize the benefits and minimize the environmental impact is significant. Majority of prior works focus on plant specific decision making issues including performance analysis. This study proposes a hybrid Data Envelopment Analysis (DEA), Goal Programming (GP) and Mixed Integer Linear Programming (MILP) model to assess the performance of incineration plants, in a specific region, to enhance overall power production, consumption of waste and reduction of emissions. This model not only helps the plant operators to evaluate the effectiveness of incineration but also facilitates the policy makers to plan for overall waste management of the region through decision-making on adding and closing plants on the basis of their efficiency. Majority of prior studies on incineration plants emphasize on how to improve their performance on heat and power production and neglect the waste management aspects. Additionally, optimizing benefits and minimizing negative outputs through fixing targets in order to make decision on shutting down the suboptimal plants has not been modeled in prior research. This research combines both the aspects and addresses the overall performance enhancement of incineration plants within a region from both policy makers and plant operatorsâ perspectives. The proposed combined DEA, GP and MILP model enables to optimize incineration plants performance within a region by deriving efficiency of each plant and identifying plants to close down on the basis of their performance. The proposed model has been applied to a group of 22 incineration plants in the UK using secondary data in order to demonstrate the effectiveness of the model.
Endovascular repair of aortic dissection and intramural hematoma: indications and serial changes
Thoracic aortic dissection (AD) is one of the most common aortic emergencies. It can be fatal if not promptly diagnosed and treated. Intramural hematoma (IMH) of the aorta is recognized as distinct from classic (double-barreled) AD. IMH also frequently leads to aortic emergency, which can be fatal unless rapidly diagnosed and treated.Recently, thoracic endovascular aortic repair (TEVAR) has been used for the treatment of complications caused by AD. TEVAR is also a viable option for the treatment of complicated IHM. In this article, we review the details of TEVAR as treatment options for AD and IMH, including the indications for TEVAR, imaging, and follow-up
Enhancement of Jc in MgB2 thin films on Si substrate with pinning centers introduced by deposition in O2 atmosphere
Relative Activation of Human Pregnane X Receptor versus Constitutive Androstane Receptor Defines Distinct Classes of CYP2B6 and CYP3A4 Inducers
Both the human pregnane X receptor (hPXR) and constitutive androstane receptor (hCAR) are capable of regulating CYP3A4 and CYP2B6 gene expression. However, the majority of currently identified CYP3A4 and CYP2B6 inducers are confirmed activators of hPXR but not hCAR. To compare these receptors with respect to their chemical selectivities, 16 drugs known to induce CYP3A4 and/or CYP2B expression were evaluated for relative activation of hPXR versus hCAR. Because of the high basal but low chemical-induced activation of hCAR in immortalized cells, alternative methods were used to evaluate hCAR activation potential. Thirteen of the 16 compounds were classified as moderate to strong hPXR activators. In contrast, carbamazepine (CMZ), efavirenz (EFV), and nevirapine (NVP) were classified as negligible or weak hPXR activators at concentrations associated with efficacious CYP2B6 reporter or endogenous gene induction in primary human hepatocytes, suggesting potential activation of hCAR. Subsequent experiments demonstrated that these three drugs efficiently induced nuclear accumulation of in vivo-transfected enhanced yellow fluorescent protein-hCAR and significantly increased expression of a CYP2B6 reporter gene when hCAR was expressed in CARâ/â mice. In addition, using a recently identified, chemically responsive splice variant of hCAR (hCAR3), the hCAR activation profiles of the 16 compounds were evaluated. By combining results from the hPXR- and hCAR3-based reporter gene assays, these inducers were classified as hPXR, hCAR, or hPXR/hCAR dual activators. Our results demonstrate that CMZ, EFV, and NVP induce CYP2B6 and CYP3A4 preferentially through hCAR and that hCAR3 represents a sensitive tool for in vitro prediction of chemical-mediated human CAR activation
Garlic Extract Diallyl Sulfide (DAS) Activates Nuclear Receptor CAR to Induce the Sult1e1 Gene in Mouse Liver
Constituent chemicals in garlic extract are known to induce phase I and phase II enzymes in rodent livers. Here we have utilized Car+/+ and Carâ/â mice to demonstrate that the nuclear xenobiotic receptor CAR regulated the induction of the estrogen sulfotransferase Sult1e1 gene by diallyl sulfide (DAS) treatment in mouse liver. DAS treatment caused CAR accumulation in the nucleus, resulting in a remarkable increase of SULT1E1 mRNA (3,200 fold) and protein in the livers of Car+/+ females but not of Carâ/â female mice. DAS also induced other CAR-regulated genes such as Cyp2b10, Cyp3a11 and Gadd45ÎČ. Compared with the rapid increase of these mRNA levels, which began as early as 6 hourrs after DAS treatment, the levels of SULT1E1 mRNA began increasing after 24 hours. This slow response to DAS suggested that CAR required an additional factor to activate the Sult1e1 gene or that this activation was indirect. Despite the remarkable induction of SULT1E1, there was no decrease in the serum levels of endogenous E2 or increase of estrone sulfate while the clearance of exogenously administrated E2 was accelerated in DAS treated mice
Global Well-posedness of an Inviscid Three-dimensional Pseudo-Hasegawa-Mima Model
The three-dimensional inviscid Hasegawa-Mima model is one of the fundamental
models that describe plasma turbulence. The model also appears as a simplified
reduced Rayleigh-B\'enard convection model. The mathematical analysis the
Hasegawa-Mima equation is challenging due to the absence of any smoothing
viscous terms, as well as to the presence of an analogue of the vortex
stretching terms. In this paper, we introduce and study a model which is
inspired by the inviscid Hasegawa-Mima model, which we call a
pseudo-Hasegawa-Mima model. The introduced model is easier to investigate
analytically than the original inviscid Hasegawa-Mima model, as it has a nicer
mathematical structure. The resemblance between this model and the Euler
equations of inviscid incompressible fluids inspired us to adapt the techniques
and ideas introduced for the two-dimensional and the three-dimensional Euler
equations to prove the global existence and uniqueness of solutions for our
model. Moreover, we prove the continuous dependence on initial data of
solutions for the pseudo-Hasegawa-Mima model. These are the first results on
existence and uniqueness of solutions for a model that is related to the
three-dimensional inviscid Hasegawa-Mima equations
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