667 research outputs found
A Cluster of Compact Radio Sources in NGC 2024 (Orion B)
We present deep 3.6 cm radio continuum observations of the H II region NGC
2024 in Orion B obtained using the Very Large Array in its A-configuration,
with angular resolution. We detect a total of 25 compact radio
sources in a region of . We discuss the nature of these sources
and its relation with the infrared and X-ray objects in the region. At least
two of the radio sources are obscured proplyds whose morphology can be used to
restrict the location of the main ionizing source of the region. This cluster
of radio sources is compared with others that have been found in regions of
recent star formation.Comment: 21 pages, 7 figure
Selective and regulated trapping of nicotinic receptor weak base ligands and relevance to smoking cessation
© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in eLife 6 (2017): e25651, doi:10.7554/eLife.25651.To better understand smoking cessation, we examined the actions of varenicline (Chantix) during long-term nicotine exposure. Varenicline reduced nicotine upregulation of α4β2-type nicotinic receptors (α4β2Rs) in live cells and neurons, but not for membrane preparations. Effects on upregulation depended on intracellular pH homeostasis and were not observed if acidic pH in intracellular compartments was neutralized. Varenicline was trapped as a weak base in acidic compartments and slowly released, blocking 125I-epibatidine binding and desensitizing α4β2Rs. Epibatidine itself was trapped; 125I-epibatidine slow release from acidic vesicles was directly measured and required the presence of α4β2Rs. Nicotine exposure increased epibatidine trapping by increasing the numbers of acidic vesicles containing α4β2Rs. We conclude that varenicline as a smoking cessation agent differs from nicotine through trapping in α4β2R-containing acidic vesicles that is selective and nicotine-regulated. Our results provide a new paradigm for how smoking cessation occurs and suggest how more effective smoking cessation reagents can be designed.This work was supported by National Institutes of Health RO1DA 035430 and a Pilot Project from the University of Chicago Can-
cer Center
A view of the implanted SiC damage by Rutherford backscattering spectroscopy, spectroscopic ellipsometry, and transmission electron microscopy
4H-SiC single crystalline substrates were implanted at room temperature with 150 keV Al+ ions
using fluences of 4 1014, 1 1015, and 2 1015 cm−2 with current density of 2.5 A cm−2. The
samples were subsequently annealed at 1100 °C in N2 for 1 h in order to analyze their structural
recovery. The disorder induced in both sublattices by the Al+ ions was studied by backscattering
spectrometry in channeling geometry with a 3.5 MeV He2+ beam. The results were compared with
the optical properties of the samples measured by spectroscopic ellipsometry. In a previous work,
we concluded that during the postimplantation annealing of a highly damaged SiC crystalline
material the short distance order can be recovered, while the long distance disorder remains. We also
presented the possibility to have grains of different polytypes oriented faraway from the original
direction. Now, this alternative is confirmed by the cross-sectional transmission and high resolution
electron microscopy studies, carried out to obtain information about the crystal structure.Ministerio de Cienncias y Tecnología español-MAT2002-02843 (70% de fondos FEDER)Acuerdo de Colaboración Científica Húngaro-Españo-lE27 / 2001Fondo de Investigaciones Científicas de Hungría (OTKA)-T032029, T047011, T043704 y K6172
Progression of White Matter Lesion Volume and Health-Related Quality of Life in Patients with Symptomatic Atherosclerotic Disease: The SMART-MR Study
Objectives. Mechanisms influencing the course of physical and mental functioning after an atherosclerotic event are unclear. We examined effects of white matter lesion (WML) activity on changes in functioning in patients with symptomatic atherosclerotic disease.
Methods. In 486 patients (58 ± 9 years) of the Second Manifestations of ARTerial disease-Magnetic Resonance (SMART-MR) study, volumetric WML measurements on 1.5T MRI were performed at baseline and 3.9 ± 0.4 years followup. Functioning was assessed with the modified Short-Form 12 (SF-12) questionnaire. Associations of WML progression with changes in functioning were adjusted for age, sex, and vascular risk factors.
Results. Physical functioning (baseline: 44, 10th–90th percentile 29–55) improved, whereas mental functioning (baseline: 51, 10th–90th percentile 32–60) declined during followup. WML progression (highest quartile versus rest) contributed to a stronger decline in mental functioning (B = −1.76, 95% CI −3.11 to −0.42), but did not influence changes in physical functioning. Conclusions. Progression of WML volume contributes to a decline in mental functioning in patients with symptomatic atherosclerotic disease
Congenital hypothyroidism and concurrent renal insufficiency in a kitten
A 3-month-old male domestic short-hair kitten was presented with chronic constipation
and disproportionate dwarfism. Radiographs of the long bones and spine revealed delayed
epiphyseal ossification and epiphyseal dysgenesis. Diagnosis of congenital primary
hypothyroidism was confirmed by low serum total thyroxine and high thyroid stimulating
hormone concentrations. Appropriate supplementation of levothyroxine was instituted. The
kitten subsequently developed mild renal azotaemia and renal proteinuria, possibly as a
consequence of treatment or an unmasked congenital renal developmental abnormality. Early
recognition, diagnosis and treatment are vital as alleviation of clinical signs may depend on
the cat’s age at the time of diagnosis.http://www.jsava.co.zaam201
Использование растровых графических редакторов для обработки археологических материалов
В данной работе предлагается к рассмотрению компьютерная графика в качестве инструмента для создания стратиграфических чертежей и приводится краткое описание технологии, которая сегодня широко используется при составлении отчетов многих археологических экспедиций в Крыму
Prediction of Cardiovascular Events by Using Non-Vascular Findings on Routine Chest CT
Background: Routine computed tomography (CT) examinations contain an abundance of findings unrelated to the diagnostic question. Those with prognostic significance may contribute to early detection and treatment of disease, irrelevant findings can be ignored. We aimed to assess the association between unrequested chest CT findings in lungs, mediastinum and pleura and future cardiovascular events. Methods: Multi-center case-cohort study in 5 tertiary and 3 secondary care hospitals involving 10410 subjects who underwent routine chest CT for non-cardiovascular reasons. 493 cardiovascular hospitalizations or deaths were recorded during an average follow-up time of 17.8 months. 1191 patients were randomly sampled to serve as a control subcohort. Hazard ratios and annualized event rates were calculated. Results: Abnormalities in the lung (26–44%), pleura (14–15%) and mediastinum (20%) were common. Hazard ratios after adjustment for age and sex were for airway wall thickening 2.26 (1.59–3.22), ground glass opacities 2.50 (1.72–3.62), consolidations 1.97 (1.12–3.47), pleural effusions 2.77 (1.81–4.25) and lymph-nodes 2.04 (1.40–2.96). Corresponding annual event rates were 5.5%, 6.0%, 3.8%, 10.2 % and 4.4%. Conclusions: We have identified several common chest CT findings that are predictive for future risk of cardiovascular events and found that other findings have little utility for this. The added value of the non-vascular predictors to establishe
Enteritis hemorrágica por adenovirus en pavos
Hemorrhagic enteritis (HE) in 4 to 11 weeks old turkeys is described by the first time in Colombia, based on gross, morphologic and electron microscopic studies. Sick animales presented enteritis and splenomegaly as the main findings. Mononuclear cells of the lamina propria of the small intestine presented intranuclear inclusion bodies. In the spleen these bodies were seen in most of the cells of white and red pulp. The inclusion bodies were slightly eosinophilic and the chromatin was displaced to the nuclear membrane. A basophilic round flattened body, displaced to a nuclear pole, suggested a nucleolus. Ultrastructural studies of the inclusion development from the initial appearance of a cristaloid material to the final formation of large amounts of capsids and virions are described. Negative staing of spleen macerates presented typical adenovirus particles but these particles were not detected in the intestinal content by the same technique.Se describe por primera vez en Colombia la enteritis hemorrágica (EH), en pavos de 4 a 11 semanas de edad, mediante estudios macroscópicos, hislológicos y de microscopía electrónica. Se demostró una enteritis hemorrágica severa, y esplenomegalia con inclusiones intranucleares en la mayoría de las células de la pulpa blanca esplénica y en algunos mononucleares en el intestino delgado. Las inclusiones son características; consisten de un centro eosinófilico, rodeado de cromatina densa y condensada sobre la membrana nuclear y de una estructura muy basófila y densa sobre un polo nuclear que parece corresponder a un nucleolo. Al microscopio electrónico se aprecian fases del desarrollo viral, desde un material filamentoso y amorfo hasta la formación de grandes acúmulos de viriones y cápsides de 70-80 nm de diámetro con morfología típica de adenovirus. Los viriones se demostraron fácilmente en macerados de bazo fijado en formol, teñidos negativamente con fosfotungstato de potasio; no se visualizaron en el contenido intestinal hemorrágico estudiado con el mismo método. El estudio de microscopía de luz de bazo e intestino es suficiente para establecer el diagnóstico de esta entidad
Charged particle-like branes in ABJM
We study the effect of adding lower dimensional brane charges to the 't Hooft
monopole, di-baryon and baryon vertex configurations in . We show that these configurations capture the background fluxes
in a way that depends on the induced charges, and therefore, require additional
fundamental strings in order to cancel the worldvolume tadpoles. The study of
the dynamics reveals that the charges must lie inside some interval in order to
find well defined configurations, a situation familiar from the baryon vertex
in with charges. For the baryon vertex and the di-baryon the
number of fundamental strings must also lie inside an allowed interval. Our
configurations are sensitive to the flat -field recently suggested in the
literature. We make some comments on its possible role. We also discuss how
these configurations are modified in the presence of a non-zero Romans mass.Comment: 31 pages, 14 figures, discussion of charges improved, published
versio
Surface Localization of Buried III–V Semiconductor Nanostructures
In this work, we study the top surface localization of InAs quantum dots once capped by a GaAs layer grown by molecular beam epitaxy. At the used growth conditions, the underneath nanostructures are revealed at the top surface as mounding features that match their density with independence of the cap layer thickness explored (from 25 to 100 nm). The correspondence between these mounds and the buried nanostructures is confirmed by posterior selective strain-driven formation of new nanostructures on top of them, when the distance between the buried and the superficial nanostructures is short enough (d = 25 nm)
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