2,752 research outputs found
High-performance thermal emitters based on laser engineered metal surfaces
Effective thermal management is of paramount importance for all high-temperature
systems operating under vacuum. Cooling of such systems relies mainly on radiative heat transfer
requiring high spectral emissivity of surfaces, which is strongly affected by the surface condition.
Pulsed laser structuring of stainless steel in air resulted in the spectral hemispherical emissivity
values exceeding 0.95 in the 2.5–15 µm spectral region. The effects of surface oxidation and
topography on spectral emissivity as well as high temperature stability of the surface structures
were examined. High performance stability of the laser textured surfaces was confirmed after
thermal aging studies at 320°C for 96 hour
Alternative end-joining originates stable chromosome aberrations induced by etoposide during targeted inhibition of DNA-PKcs in ATM-deficient tumor cells
ATM and DNA-PKcs coordinate the DNA damage response at multiple levels following the exposure to chemotherapy. The Topoisomerase II poison etoposide (ETO) is an effective chemotherapeutic agent that induces DNA double-strand breaks (DSB), but it is responsible from the chromosomal rearrangements frequently found in therapy-related secondary tumors. Targeted inhibition of DNA-PKcs in ATM-defective tumors combined with radio- or chemotherapy has been proposed as relevant therapies. Here, we explored the DNA repair mechanisms and the genetic consequences of targeting the non-oncogenic addiction to DNA-PKcs of ATM-defective tumor cells after exposure to ETO. We demonstrated that chemical inhibition of DNA-PKcs followed by treatment with ETO resulted in the accumulation of chromatid breaks and decreased mitotic index in both A-T cells and ATM-knocked-down (ATMkd) tumor cells. The HR repair process in DNA-PKcs-inhibited ATMkd cells amplified the RAD51 foci number, with no correlated increase in sister chromatid exchanges. The analysis of post-mitotic DNA lesions presented an augmented number of persistent unresolved DSB, without alterations in the cell cycle progression. Long-term examination of chromosome aberrations revealed a strikingly high number of chromatid and chromosome exchanges. By using genetic and pharmacological abrogation of PARP-1, we demonstrated that alternative end-joining (alt-EJ) repair pathway is responsible for those chromosome abnormalities generated by limiting c-NHEJ activities during directed inhibition of DNA-PKcs in ATM-deficient cells. Targeting the non-oncogenic addiction to DNA-PKcs of ATM-defective tumors stimulates the DSB repair by alt-EJ, which is liable for the origin of cells carrying stable chromosome aberrations that may eventually restrict the therapeutic strategy.Fil: de Campos Nebel, Ildefonso Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Palmitelli, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Perez Maturo, Josefina. Universidad Austral. Facultad de Ciencias Biomédicas. Instituto de Investigaciones en Medicina Traslacional. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Medicina Traslacional; ArgentinaFil: Gonzalez Cid, Marcela Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin
An Atlas of the circumnuclear regions of 75 Seyfert galaxies in the near-UV with HST Advanced Camera for Surveys
We present an atlas of the central regions of 75 Seyfert galaxies imaged in
the near-UV with the Advanced Camera for Surveys of the Hubble Space Telescope
at an average resolution of ~10pc. These data complement archival high
resolution data from the Space Telescope at optical and near-IR wavelengths,
creating an extremely valuable dataset for astronomers with a broad range of
scientific interests. Our goal is to investigate the nature of the near-UV
light in these objects, its relation to the circumnuclear starburst phenomenon,
and the connection of this to the evolution and growth of the galaxy bulge and
central black hole. In this paper, we describe the near-UV morphology of the
objects and characterize the near-UV emission. We estimate the size and the
luminosity of the emitting regions and extract the luminosity profile. We also
determine the presence of unresolved compact nuclei. In addition, the
circumnuclear stellar cluster population is identified, and the contribution of
the stellar clusters to the total light, at this wavelength, is estimated. The
size of the sample allows us to draw robust statistical conclusions. We find
that {Seyfert 1} galaxies are completely dominated by its bright and compact
nucleus, that remains point-like at this resolution, while we find almost no
unresolved nucleus in Seyfert 2. The Seyfert types 1 and 2 are quite segregated
in an asymmetry vs compactness plot. Stellar clusters are found somewhat more
frequently in Sy2 (in ~70% of the galaxies) than in Sy1 (~57%), and contribute
more to the total light in Sy2, but this two differences seem to be mostly due
to the large contribution of the compact nucleus in Sy1, as the luminosity
distribution of the clusters is similar in both Sy types.Comment: Accepted for publication in AJ, 58 pages, 20 figures. High-resolution
figures for all the objects are available at
http://www.iaa.es/~manuel/publications/paper01.htm
2-Hydroxychalcone−β-cyclodextrin conjugate with pH-modulated photoresponsive binding properties
Stimuli-responsive supramolecular receptors are important building blocks for the construction of self-assembled functional materials. We report the design and synthesis of a pH- and light-responsive 2-hydroxychalcone−β-cyclodextrin conjugate (1-Ct) and its characterization by spectroscopic and computational methods. 1-Ct follows the typical reaction network of trans-chalcone-flavylium photoswitches. Upon light irradiation, 1-Ct can be photochemically converted into the cis-chalcone/hemiketal forms (1-Cc/1-B) under neutral pH conditions or to the flavylium cation (1-AH+) at acidic pH values. This stimuli-responsive β-cyclodextrin host, 1-Ct, was found to form stronger intramolecular self-inclusion complexes (Kintra = 14) than 1-AH+ (Kintra = 3) and weaker than 1-Cc/1-B (overall Kintra = 179), allowing control over their stability and binding properties by combinations of pH and light stimuli.Fundação para a Ciência e a Tecnologia | Ref. UIDB/50006/2020Fundação para a Ciência e a Tecnologia| Ref. UIDP/50006/2020Fundação para a Ciência e a Tecnologia | Ref. UIDB/04326/202
Resolving galaxies in time and space: II: Uncertainties in the spectral synthesis of datacubes
In a companion paper we have presented many products derived from the
application of the spectral synthesis code STARLIGHT to datacubes from the
CALIFA survey, including 2D maps of stellar population properties and 1D
averages in the temporal and spatial dimensions. Here we evaluate the
uncertainties in these products. Uncertainties due to noise and spectral shape
calibration errors and to the synthesis method are investigated by means of a
suite of simulations based on 1638 CALIFA spectra for NGC 2916, with
perturbations amplitudes gauged in terms of the expected errors. A separate
study was conducted to assess uncertainties related to the choice of
evolutionary synthesis models. We compare results obtained with the Bruzual &
Charlot models, a preliminary update of them, and a combination of spectra
derived from the Granada and MILES models. About 100k CALIFA spectra are used
in this comparison.
Noise and shape-related errors at the level expected for CALIFA propagate to
0.10-0.15 dex uncertainties in stellar masses, mean ages and metallicities.
Uncertainties in A_V increase from 0.06 mag in the case of random noise to 0.16
mag for shape errors. Higher order products such as SFHs are more uncertain,
but still relatively stable. Due to the large number statistics of datacubes,
spatial averaging reduces uncertainties while preserving information on the
history and structure of stellar populations. Radial profiles of global
properties, as well as SFHs averaged over different regions are much more
stable than for individual spaxels. Uncertainties related to the choice of base
models are larger than those associated with data and method. Differences in
mean age, mass and metallicity are ~ 0.15 to 0.25 dex, and 0.1 mag in A_V.
Spectral residuals are ~ 1% on average, but with systematic features of up to
4%. The origin of these features is discussed. (Abridged)Comment: A&A, accepte
Standard comparison of local mental health care systems in eight European countries
Sistema de Salut Mental; Comparació d'atenció a la salut mentalMental Health System; Mental health care comparisonSistema de Salud Mental; Comparación de atención a la salud mentalAims: There is a need of more quantitative standardised data to compare local Mental Health Systems (MHSs) across international jurisdictions. Problems related to terminological variability and commensurability in the evaluation of services hamper like-with-like comparisons and hinder the development of work in this area. This study was aimed to provide standard assessment and comparison of MHS in selected local areas in Europe, contributing to a better understanding of MHS and related allocation of resources at local level and to lessen the scarcity in standard service comparison in Europe. This study is part of the Seventh Framework programme REFINEMENT (Research on Financing Systems' Effect on the Quality of Mental Health Care in Europe) project.
Methods: A total of eight study areas from European countries with different systems of care (Austria, England, Finland, France, Italy, Norway, Romania, Spain) were analysed using a standard open-access classification system (Description and Evaluation of Services for Long Term Care in Europe, DESDE-LTC). All publicly funded services universally accessible to adults (≥18 years) with a psychiatric disorder were coded. Care availability, diversity and capacity were compared across these eight local MHS.
Results: The comparison of MHS revealed more community-oriented delivery systems in the areas of England (Hampshire) and Southern European countries (Verona - Italy and Girona - Spain). Community-oriented systems with a higher proportion of hospital care were identified in Austria (Industrieviertel) and Scandinavian countries (Sør-Trøndelag in Norway and Helsinki-Uusimaa in Finland), while Loiret (France) was considered as a predominantly hospital-based system. The MHS in Suceava (Romania) was still in transition to community care.
Conclusions: There is a significant variation in care availability and capacity across MHS of local areas in Europe. This information is relevant for understanding the process of implementation of community-oriented mental health care in local areas. Standard comparison of care provision in local areas is important for context analysis and policy planning.The REFINEMENT project has received funding from the European Commission under the Seventh Framework Programme (7FP) and lies within the Specific Programme ‘Cooperation’ – Theme ‘Health’: HEALTH.2010.3.2–1: Financing systems’ effect on quality of health care. Duration: 1 January 2011 to 31 December 2013. 7FP. Project number: 261459
Workplace interventions for cardiovascular diseases: protocol of a systematic review and meta-analysis
INTRODUCTION: Cardiovascular diseases (CVDs) are the number one cause of death globally, impacting on public and private sectors. Current traditional interventions to prevent CVDs are mainly provided in healthcare centres and even when they are effective, they are not enough to reduce the rising prevalence; therefore, additional strategies are needed. Evidence suggests that health interventions in the workplace supply numerous benefits improving cardiovascular risk factor profiles in individuals. Hence, the aim of this systematic review and meta-analysis is to collate the evidence from randomised controlled trials, cluster randomised trials and quasi-experimental studies of workplace interventions to determine their effectiveness in terms of improving cardiovascular risk factors and preventing CVDs. METHODS AND ANALYSIS: EMBASE, PsycINFO, PubMed, the Cochrane Central Register of Controlled Trials, LILACS, Scopus, Web of Science, WHO International Clinical Trials Registry Platform, ClinicalTrials.gov and ProQuest Dissertations & Theses Global will be searched to include articles on workplace interventions in adults for CVDs events, cardiometabolic risk factors or behavioural risk factors. The study selection, data extraction, risk of bias and the assessment of the quality of the body of evidence will be conducted by two reviewers working in parallel and disagreements will be resolved by consensus or consultations with a third reviewer. Data synthesis will be done by meta-analysis using random-effects models when possible, otherwise the vote counting method will be applied. Statistical heterogeneity will be assessed by a χ(2) test and I(2) statistics. The quality of the body of evidence for each outcome will be assessed by applying the Grading of Recommendations, Assessment, Development and Evaluation approach. ETHICS AND DISSEMINATION: Ethical approval is not required for this systematic review protocol. The results of the systematic review will be published in a peer-reviewed journal and will be publicly available. PROSPERO REGISTRATION NUMBER: CRD42021276161
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