5,955 research outputs found

    Architecture of coatomer: Molecular characterization of delta-COP and protein interactions within the complex

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    Copyright © 2011 by The Rockefeller University Press.Coatomer is a cytosolic protein complex that forms the coat of COP I-coated transport vesicles. In our attempt to analyze the physical and functional interactions between its seven subunits (coat proteins, [COPs] alpha-zeta), we engaged in a program to clone and characterize the individual coatomer subunits. We have now cloned, sequenced, and overexpressed bovine alpha-COP, the 135-kD subunit of coatomer as well as delta-COP, the 57-kD subunit and have identified a yeast homolog of delta-COP by cDNA sequence comparison and by NH2-terminal peptide sequencing. delta-COP shows homologies to subunits of the clathrin adaptor complexes AP1 and AP2. We show that in Golgi-enriched membrane fractions, the protein is predominantly found in COP I-coated transport vesicles and in the budding regions of the Golgi membranes. A knock-out of the delta-COP gene in yeast is lethal. Immunoprecipitation, as well as analysis exploiting the two-hybrid system in a complete COP screen, showed physical interactions between alpha- and epsilon-COPs and between beta- and delta-COPs. Moreover, the two-hybrid system indicates interactions between gamma- and zeta-COPs as well as between alpha- and beta' COPs. We propose that these interactions reflect in vivo associations of those subunits and thus play a functional role in the assembly of coatomer and/or serve to maintain the molecular architecture of the complex.This work was supported by The Deutsche Forschungsgemeinschaft (SFB 352), the Human Frontier Science Program, and the Swiss National Science Foundation No. 31-43366.95

    Survival and quality of life benefit after endoscopic management of malignant central airway obstruction

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    Although interventional management of malignant central airway obstruction (mCAO) is well established, its impact on survival and quality of life (QoL) has not been extensively studied.We prospectively assessed survival, QoL and dyspnea (using validated EORTC questionnaire) in patients with mCAO 1 day before interventional bronchoscopy, 1 week after and every following month, in comparison to patients who declined this approach. Material/Patients/Methods: 36 patients underwent extensive interventional bronchoscopic management as indicated, whereas 12 declined. All patients received full chemotherapy and radiotherapy as indicated. Patients of the 2 groups were matched for age, comorbidities, type of malignancy and level of obstruction. Follow up time was 8.0±8.7 (range 1-38) months.Mean survival for intervention and control group was 10±9 and 4±3 months respectively (p=0.04). QoL improved significantly in intervention group patients up to the 6(th) month (p<0.05) not deteriorating for those surviving up to 12 months. Dyspnea decreased in patients of the intervention group 1 month post procedure remaining reduced for survivors over the 12th month. Patients of the control group had worse QoL and dyspnea in all time points.Interventional management of patients with mCAO, may achieve prolonged survival with sustained significant improvement of QoL and dyspnea

    Nonequilibrium Dynamics in Noncommutative Spacetime

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    We study the effects of spacetime noncommutativity on the nonequilibrium dynamics of particles in a thermal bath. We show that the noncommutative thermal bath does not suffer from any further IR/UV mixing problem in the sense that all the finite-temperature non-planar quantities are free from infrared singularities. We also point out that the combined effect of finite temperature and noncommutative geometry has a distinct effect on the nonequilibrium dynamics of particles propagating in a thermal bath: depending on the momentum of the mode of concern, noncommutative geometry may switch on or switch off their decay and thermalization. This momentum dependent alternation of the decay and thermalization rates could have significant impacts on the nonequilibrium phenomena in the early universe at which spacetime noncommutativity may be present. Our results suggest a re-examination of some of the important processes in the early universe such as reheating after inflation, baryogenesis and the freeze-out of superheavy dark matter candidates.Comment: 24 pages, 2 figure

    Morphologic and Genetic Analysis of Synhimantus (Synhimantus) laticeps from a Long-Eared Owl (Asio otus)

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    The long-eared owl (Asio otus) is a medium-sized owl species that is well-distributed in almost all of the territories in Portugal. Nematodes were found in the oral cavity of a long-eared owl (A. otus) admitted to CRASSA (Wildlife Rehabilitation Centre of Santo Andre). During a physical exam and stabilization of the bird, five nematodes were collected. The worms were examined and measured under light microscopy, and photos were taken. After a morphological analysis was conducted, all the nematodes (five females) were identified as Synhimantus (Synhimantus) laticeps. Two specimens were subjected to molecular analysis, which confirmed the result. This study provides a combined morphological and genetic approach to S. laticeps. To the authors' best knowledge, this is the first report including genetic sequencing of S. laticeps in a long-eared owl (A. otus) from Portugal.This work was supported by the projects UIDB/CVT/00772/2020 and LA/P/0059/2020 funded by the Portuguese Foundation for Science and Technology (FCT). S.S.-S. thanks FCT for the financial support of his PhD work under the 2021 scholarship 2021.09461.BD contract through the Maria de Sousa-2021 program

    NADPH oxidase and reactive oxygen species contribute to alcohol-induced microglial activation and neurodegeneration

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    <p>Abstract</p> <p>Background</p> <p>Activation of microglia causes the production of proinflammatory factors and upregulation of NADPH oxidase (NOX) that form reactive oxygen species (ROS) that lead to neurodegeneration. Previously, we reported that 10 daily doses of ethanol treatment induced innate immune genes in brain. In the present study, we investigate the effects of chronic ethanol on activation of NOX and release of ROS, and their contribution to ethanol neurotoxicity.</p> <p>Methods</p> <p>Male C57BL/6 and NF-κB enhanced GFP mice were treated intragastrically with water or ethanol (5 g/kg, i.g., 25% ethanol w/v) daily for 10 days. The effects of chronic ethanol on cell death markers (activated caspase-3 and Fluoro-Jade B), microglial morphology, NOX, ROS and NF-κB were examined using real-time PCR, immunohistochemistry and hydroethidine histochemistry. Also, Fluoro-Jade B staining and NOX gp91<sup>phox </sup>immunohistochemistry were performed in the orbitofrontal cortex (OFC) of human postmortem alcoholic brain and human moderate drinking control brain.</p> <p>Results</p> <p>Ethanol treatment of C57BL/6 mice showed increased markers of neuronal death: activated caspase-3 and Fluoro-Jade B positive staining with Neu-N (a neuronal marker) labeling in cortex and dentate gyrus. The OFC of human post-mortem alcoholic brain also showed significantly more Fluoro-Jade B positive cells colocalized with Neu-N, a neuronal marker, compared to the OFC of human moderate drinking control brain, suggesting increased neuronal death in the OFC of human alcoholic brain. Iba1 and GFAP immunohistochemistry showed activated morphology of microglia and astrocytes in ethanol-treated mouse brain. Ethanol treatment increased NF-κB transcription and increased NOX gp91<sup>phox </sup>at 24 hr after the last ethanol treatment that remained elevated at 1 week. The OFC of human postmortem alcoholic brain also had significant increases in the number of gp91<sup>phox </sup>+ immunoreactive (IR) cells that are colocalized with neuronal, microglial and astrocyte markers. In mouse brain ethanol increased gp91<sup>phox </sup>expression coincided with increased production of O<sub>2</sub><sup>- </sup>and O<sub>2</sub><sup>- </sup>- derived oxidants. Diphenyleneiodonium (DPI), a NOX inhibitor, reduced markers of neurodegeneration, ROS and microglial activation.</p> <p>Conclusions</p> <p>Ethanol activation of microglia and astrocytes, induction of NOX and production of ROS contribute to chronic ethanol-induced neurotoxicity. NOX-ROS and NF-κB signaling pathways play important roles in chronic ethanol-induced neuroinflammation and neurodegeneration.</p

    Coherent Electron-Phonon Coupling in Tailored Quantum Systems

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    The coupling between a two-level system and its environment leads to decoherence. Within the context of coherent manipulation of electronic or quasiparticle states in nanostructures, it is crucial to understand the sources of decoherence. Here, we study the effect of electron-phonon coupling in a graphene and an InAs nanowire double quantum dot. Our measurements reveal oscillations of the double quantum dot current periodic in energy detuning between the two levels. These periodic peaks are more pronounced in the nanowire than in graphene, and disappear when the temperature is increased. We attribute the oscillations to an interference effect between two alternative inelastic decay paths involving acoustic phonons present in these materials. This interpretation predicts the oscillations to wash out when temperature is increased, as observed experimentally.Comment: 11 pages, 4 figure

    Stabilization of Tollmien-Schlichting Waves by Mode Interaction

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    Decreasing skin friction in boundary layers attached to aircraft wings can have an impact in both fuel consumption and pollutant production, which are becoming crucial to reduce operation costs and meet environmental regulations, respectively. Skin friction in turbulent boundary layers is about ten times that of laminar boundary layers. Thus, an obvious method to reduce friction drag is to delay transition to turbulence, which is a fairly involved process in real aircraft wings [J98]. Transition sis promoted either by Tollmien—Schlichting (TS) and Klebanov (K) modes [K94], with the former playing an essential role. Various methods (e.g., suction [SG00,ZLB04], wave cancellation [WAA01,LG06]) have been proposed to reduce TS modes in laminar boundary layers. Mode interaction methods have been successfully used in fluid systems to control related instabilities, such as the Rayleigh—Taylor instability [LMV01]. Here, we present some recent results on using these methods to control TS modes in a compressible, 2D boundary layer over a flat plate at zero incidence. A given unstable TS mode can be stabilized by coupling its spatial evolution with that of a second selected stable TS mode, in such a way that the stable mode takes energy from the unstable one and gives a stable coupled evolution of both modes. The coupling device is a wavetrain in the boundary layer, with appropriate wavenumber and frequency, which can be created by an array of oscillators on the wall, and promotes both (i) parametric coupling between the stable and unstable TS modes and (ii) a mean flow that is also stabilizing. Three differences with wave cancelation methods are relevant. Namely, (a) nonlinear terms play an essential role in the process; (b) the unstable TS mode is stabilized (its growth rate is decreased), not just canceled; and (c) stabilization does not depend on the phase of the incoming wave, which implies that active control is not necessary

    Medical causes of admissions to hospital among adults in Africa: a systematic review.

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    BACKGROUND: Despite the publication of several studies on the subject, there is significant uncertainty regarding the burden of disease among adults in sub-Saharan Africa (sSA). OBJECTIVES: To describe the breadth of available data regarding causes of admission to hospital, to systematically analyze the methodological quality of these studies, and to provide recommendations for future research. DESIGN: We performed a systematic online and hand-based search for articles describing patterns of medical illnesses in patients admitted to hospitals in sSA between 1950 and 2010. Diseases were grouped into bodily systems using International Classification of Disease (ICD) guidelines. We compared the proportions of admissions and deaths by diagnostic category using χ2. RESULTS: Thirty articles, describing 86,307 admissions and 9,695 deaths, met the inclusion criteria. The leading causes of admission were infectious and parasitic diseases (19.8%, 95% confidence interval [CI] 19.6-20.1), respiratory (16.2%, 95% CI 16.0-16.5) and circulatory (11.3%, 95% CI 11.1-11.5) illnesses. The leading causes of death were infectious and parasitic (17.1%, 95% CI 16.4-17.9), circulatory (16%, 95% CI 15.3-16.8) and digestive (16.2%, 95% CI 15.4-16.9). Circulatory diseases increased from 3.9% of all admissions in 1950-59 to 19.9% in 2000-2010 (RR 5.1, 95% CI 4.5-5.8, test for trend p<0.00005). The most prevalent methodological deficiencies, present in two-thirds of studies, were failures to use standardized case definitions and ICD guidelines for classifying illnesses. CONCLUSIONS: Cardiovascular and infectious diseases are currently the leading causes of admissions and in-hospital deaths in sSA. Methodological deficiencies have limited the usefulness of previous studies in defining national patterns of disease in adults. As African countries pass through demographic and health transition, they need to significantly invest in clinical research capacity to provide an accurate description of the disease burden among adults for public health policy
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