1,108 research outputs found

    Coronene: a model for ultrafast dynamics in graphene nanoflakes and PAHs

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    Datos de investigación en: http://hdl.handle.net/10366/153091[EN] Assuming a delta pulse excitation, quantum wavepackets are propagated on the excited state manifold in the energy range from 3.4-5.0 eV for coronene and 2.4-3.5 eV for circumcoronene to study the time evolution of the states as well as their lifetimes. The full-dimensional (102 and 210 degrees of freedom for coronene and circumcoronene respectively) non-adiabatic dynamics simulated with the ML-MCTDH method on twelve coupled singlet electronic states show that the different absorption spectra are only due to electronic delocalisation effects that change the excited state energies, but the structural dynamics in both compounds are identical. Breathing and tilting motions drive the decay dynamics of the electronic states away from the Frank-Condon region independently of the size of the aromatic system. This promising result allows the use of coronene as a model system for the dynamics of larger polycyclic aromatic hydrocarbons (PAHs) and graphene one dimensional sheets or nanoflakes

    Sistem Pendukung Keputusan Penentuan Penerimaan Bantuan Sembako Covid-19 Pada Desa Ujung Serdang Menggunakan Metode SMART

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    Pemberian Sembako Covid_19 pada desa ujung Serdang membutuhkan ketepatan dalam pendistribusian untuk menjaga keadilan serta kesejahtraan masyarakat. Namun dalam pemilihan penerimaan bantuan covid-19 haruslah melihat dari beberapa penilaian yang akurat. Selama ini pemberian bantuan masih menggunakan metode manual yaitu pemerintah desa beserta timnya memilih langsung masyarakat yang layak mererima bantuan sehingga sering sekali terjadi ketidaktepatan serta masih adanya budaya mengutamakan keluarga. Sistem pendukung keputusan dalam pemilihan pemberian bantuan pada masyarakat Desa Ujung Serdang sangat dibutuhkan sehingga pemerintah Desa Ujung Serdang untuk selanjutnya dapat memberikan bantuan kepada masyarakat dengan tepat sasaran dan cepat. Sistem Pendukung keputusan dengan penerapan Metode Simple Multi Attribute Rating Technique (SMART). Metode SMART digunakan untuk menganalisa dalam menentukan masyarakat yang layak mendapatkan bantuan yang dibuat berdasarkan kriteria, sistem pendukung keputusan ini dibangun dengan bahasa pemrograman Visual Basic 2010 dan database menggunakan MySQL. Penelitian ini ditargetkan dapat membantu pemerintah Desa Ujung Serdang dalam menentukan penerima bantuan Covid-19. Dari hasil penelitian yang telah dilakukan bahwa hasil kelayakan penerimaan bantuan sembako Covid-19 pada Desa Ujung Serdang yaitu Hendra Tarigan dengan nilai 92 (Layak), Richard Ginting dengan nilai 85 (Layak), Herman Sembiring dengan nilai 77 (layak), David Ginting dengan nilai 75 (Layak), Efendy Sitepu dengan nilai 68 (Layak), Pilih Ginting dengan nilai 65 (Layak), Imanuel Bukit dengan nilai 43,5 (Tidak Layak), Rejeki Ginting dengan nilai 32 (Tidak Layak), Tamrin Tarigan dengan nilai 30 (Tidak Layak), Mberngap Sembiring dengan nilai 27 Tidak Layak)

    Automatic identification of informative regions with epigenomic changes associated to hematopoiesis

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    Hematopoiesis is one of the best characterized biological systems but the connection between chromatin changes and lineage differentiation is not yet well understood. We have developed a bioinformatic workflow to generate a chromatin space that allows to classify 42 human healthy blood epigenomes from the BLUEPRINT, NIH ROADMAP and ENCODE consortia by their cell type. This approach let us to distinguish different cells types based on their epigenomic profiles, thus recapitulating important aspects of human hematopoiesis. The analysis of the orthogonal dimension of the chromatin space identify 32,662 chromatin determinant regions (CDRs), genomic regions with different epigenetic characteristics between the cell types. Functional analysis revealed that these regions are linked with cell identities. The inclusion of leukemia epigenomes in the healthy hematological chromatin sample space gives us insights on the healthy cell types that are more epigenetically similar to the disease samples. Further analysis of tumoral epigenetic alterations in hematopoietic CDRs points to sets of genes that are tightly regulated in leukemic transformations and commonly mutated in other tumors. Our method provides an analytical approach to study the relationship between epigenomic changes and cell lineage differentiation. Method availability: https://github.com/david-juan/ChromDet.European Union’s Seventh Framework Programme [FP7/2007–2013, 282510 (BLUEPRINT)]; Spanish Ministry of Economy, Industry and Competitiveness and European Regional Development Fund [Project Retos BFU2015–71241-R]. Funding for open access charge: Project Retos BFU2015–71241-R (to A.V.).Peer ReviewedPostprint (published version

    Tempol-nebivolol therapy potentiates hypotensive effect increasing NO bioavailability and signaling pathway

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    Nebivolol is a third generation beta blocker with endothelial nitric oxide synthase (eNOS) agonist properties. Considering the role of reactive oxygen species (ROS) in the uncoupling of eNOS, we hypothesized that the preadministration of an antioxidant as tempol, could improve the hypotensive response of nebivolol in normotensive animals increasing the nitric oxide (NO) bioavailability by a reduction of superoxide (O2•−) basal level production in the vascular tissue. Male Sprague Dawley rats were given tap water to drink (control group) or tempol (an antioxidant scavenger of superoxide) for 1 week. After 1 week, Nebivolol, at a dose of 3 mg/kg, was injected intravenously to the control group or to the tempol-treated group. Mean arterial pressure, heart rate, and blood pressure variability were evaluated in the control, tempol, nebivolol, and tempol nebivolol groups, as well as, the effect of different inhibitor as Nβ-nitro-l-arginine methyl ester (L-NAME, a Nitric oxide synthase blocker) or glybenclamide, a KATP channel inhibitor. Also, the expression of α,β soluble guanylate cyclase (sGC), phospho-eNOS, and phospho-vasodilator-stimulated phosphoprotein (P-VASP) were evaluated by Western Blot and cyclic guanosine monophosphate (cGMP) levels by an enzyme-linked immunosorbent assay (ELISA) commercial kit assay. We showed that pretreatment with tempol in normotensive rats produces a hypotensive response after nebivolol administration through an increase in the NO bioavailability and sGC, improving the NO/cGMP/protein kinase G (PKG) pathway compared to that of the nebivolol group. We demonstrated that tempol preadministration beneficiates the response of a third-generation beta blocker with eNOS stimulation properties, decreasing the basal uncoupling of eNOS, and improving NO bioavailability. Our results clearly open a possible new strategy therapeutic for treating hypertension.Fil: Bertera, Facundo Martin. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; ArgentinaFil: Santa Cruz, Diego Mario. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Balestrasse, Karina Beatriz. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gorzalczany, Susana Beatriz. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Höcht, Christian. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Farmacología; ArgentinaFil: Taira, Carlos Alberto. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Polizio, Ariel Héctor. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Children's exposure assessment of radiofrequency fields: comparison between spot and personal measurements

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    Radiofrequency (RF) fields are widely used and, while it is still unknown whether children are more vulnerable to this type of exposure, it is essential to explore their level of exposure in order to conduct adequate epidemiological studies. Personal measurements provide individualized information, but they are costly in terms of time and resources, especially in large epidemiological studies. Other approaches, such as estimation of time-weighted averages (TWAs) based on spot measurements could simplify the work.; The aims of this study were to assess RF exposure in the Spanish INMA birth cohort by spot measurements and by personal measurements in the settings where children tend to spend most of their time, i.e., homes, schools and parks; to identify the settings and sources that contribute most to that exposure; and to explore if exposure assessment based on spot measurements is a valid proxy for personal exposure.; When children were 8 years old, spot measurements were conducted in the principal settings of 104 participants: homes (104), schools and their playgrounds (26) and parks (79). At the same time, personal measurements were taken for a subsample of 50 children during 3 days. Exposure assessment based on personal and on spot measurements were compared both in terms of mean exposures and in exposure-dependent categories by means of Bland-Altman plots, Cohen's kappa and McNemar test.; Median exposure levels ranged from 29.73 (in children's bedrooms) to 200.10 μW/m; 2; (in school playgrounds) for spot measurements and were higher outdoors than indoors. Median personal exposure was 52.13 μW/m; 2; and median levels of assessments based on spot measurements ranged from 25.46 to 123.21 μW/m; 2; . Based on spot measurements, the sources that contributed most to the exposure were FM radio, mobile phone downlink and Digital Video Broadcasting-Terrestrial, while indoor and personal sources contributed very little (altogether <20%). Similar distribution was observed with personal measurements. There was a bias proportional to power density between personal measurements and estimates based on spot measurements, with the latter providing higher exposure estimates. Nevertheless, there were no systematic differences between those methodologies when classifying subjects into exposure categories. Personal measurements of total RF exposure showed low to moderate agreement with home and bedroom spot measurements and agreed better, though moderately, with TWA based on spot measurements in the main settings where children spend time (homes, schools and parks; Kappa = 0.46).; Exposure assessment based on spot measurements could be a feasible proxy to rank personal RF exposure in children population, providing that all relevant locations are being measured

    Neuromorphic weighted sum with magnetic skyrmions

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    Integrating magnetic skyrmion properties into neuromorphic computing promises advancements in hardware efficiency and computational power. However, a scalable implementation of the weighted sum of neuron signals, a core operation in neural networks, has yet to be demonstrated. In this study, we exploit the non-volatile and particle-like characteristics of magnetic skyrmions, akin to synaptic vesicles and neurotransmitters, to perform this weighted sum operation in a compact, biologically-inspired manner. To this aim, skyrmions are electrically generated in numbers proportional to the input with an efficiency given by a non-volatile weight. These chiral particles are then directed using localized current injections to a location where their presence is quantified through non-perturbative electrical measurements. Our experimental demonstration, currently with two inputs, can be scaled to accommodate multiple inputs and outputs using a crossbar array design, potentially nearing the energy efficiency observed in biological systems.Comment: 12 pages, 5 figure
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