1,695 research outputs found
Molecular identification of the transient species mediating the deactivation dynamics of solvated guanosine and deazaguanosine
Small structural alterations of the purine/pyrimidine core have been related to important photophysical changes, such as the loss of photostability. Similarly to canonical nucleobases, solute-solvent interactions can lead to a change in the excited state lifetimes and/or to the interplay of different states in the photophysics of these modified nucleobases. To shed light on both effects, we here report a complete picture of the absorption spectra and excited state deactivation of deoxyguanosine and its closely related derivative, deoxydeazaguanosine, in water and methanol through the mapping of the excited state potential energy surfaces and molecular dynamics simulations at the TD-DFT level of theory. We show that the N by CH exchange in the imidazole ring of deoxyguanosine translates into a small red-shift of the bright states and slightly faster dynamics. In contrast, changing solvent from water to methanol implies the opposite, i.e., that the deactivation of both systems to the ground state is significantly hindered
High-resolution seismic stratigraphy and morphology of the Scan Basin contourite fan, southern Scotia Sea, Antarctica
Photophysical Characterization of Isoguanine in a Prebiotic-Like Environment
It is intriguing how a mixture of organic molecules
survived the prebiotic UV fluxes and evolved into the actual
genetic building blocks. Scientists are trying to shed light on
this issue by synthesizing nucleic acid monomers and their
analogues under prebiotic Era-like conditions and by exploring their excited state dynamics. To further add to this
important body of knowledge, this study discloses new
insights into the photophysical properties of protonated
isoguanine, an isomorph of guanine, using steady-state and
femtosecond broadband transient absorption spectroscopies, and quantum mechanical calculations. Protonated isoguanine
decays in ultrafast time scales following 292 nm excitation,
consistently with the barrierless paths connecting the bright
S1 (ππ*) state with different internal conversion funnels.
Complementary calculations for neutral isoguanine predict
similar photophysical properties. These results demonstrate
that protonated isoguanine can be considered photostable in
contrast to protonated guanine, which exhibits 40-fold longer
excited state lifetimesThe authors acknowledge funding from the National Science
Foundation (Grant No. CHE-1800052), the Ramón y Cajal
Program (Grant: RYC-2016-20489) and the Ministerio de Ciencia,
Innovación y Universidades (PGC2018-094644-B-C21, PID2021-
125207NB-C31 and PRE2019-090448 projects). L. M. F. thanks
the Madrid Government (Comunidad de Madrid-Spain) under
the Multiannual Agreement with Universidad Autónoma de
Madrid in the line Support to Young Researchers, in the context
of the V PRICIT (Regional Programme of Research and
Technological Innovation) (SI3/PJI/2021-00331
Explosive Strength Capacity in the Lower Limbs of Primary Education School Children According to Environment
The objective of this study was to compare the corporal composition and the explosive strength capacity of lower limbs in primary school students from two different schools in the locality of Martos (Jaén). One of these schools was located in a marginalized neighbourhood where families of low socioeconomic status lived and the other was near the town centre with families of medium to high socioeconomic status. The aim was to evaluate these variables at two different moments in time, i.e., at the beginning and at the end of the school year, to see if the obtained results remained the same. A total of 147 primary school students (6–12 years old) participated in the study, divided into 4 subgroups, according to sex and school. Body composition and explosive strength capacity of the lower limbs were evaluated using the vertical jump test. For independent samples, T tests were performed to obtain the existing differences through the SPSS v 19.0 programme. It was found that according to the first measurement at the beginning of the year, participants from a medium-high socioeconomic background obtained better results, while the second measurement showed that results equalized and even reversed. This could have been due to the level of performed physical activity
Ejercicio profesional del diseño industrial 2 : un acercamiento al análisis de algunas de las especialidades más dinámicas en México
1 archivo PDF (153 páginas)Con este segundo tomo de este título, renace el espíritu de un proyecto académico del Grupo de Investigación DeiGmas que busca promover el diálogo entre la comunidad del diseño, en torno a la construcción de conceptos disciplinarios propios. El valor esencial de la presente publicación radica en que ofrece a los lectores una conjunción de ideas de profesionales experimentados en diversas especialidades del diseño industrial, sustentadas en su experiencia concreta del quehacer cotidiano en organizaciones nacionales de distinta índole
Wind kinetic energy climatology and effective resolution for the ERA5 reanalysis
Producción CientíficaERA5 represents the state of the art for atmospheric reanalyses and is widely used in meteorological and climatological research. In this work, this dataset is evaluated using the wind kinetic energy spectrum. Seasonal climatologies are generated for 30° latitudinal bands in the Northern Hemisphere (periodic domain) and over the North Atlantic area (limited-area domain). The spectra are also assessed to determine the effective resolution of the reanalysis. The results present notable differences between the latitudinal domains, indicating that ERA5 is properly capturing the synoptic conditions. The seasonal variability is adequate too, being winter the most energetic, and summer the least energetic season. The limited area domain results introduce a larger energy density and range. Despite the good results for the synoptic scales, the reanalysis’ spectra are not able to properly reproduce the dissipation rates at mesoscale. This is a source of uncertainties which needs to be taken into account when using the dataset. Finally, a cyclone tropical transition is presented as a case study. The spectrum generated shows a clear difference in energy density at every wavelength, as expected for a highly-energetic status of the atmosphere.Ministerio de Asuntos Económicos y Transformación Digital y Universidad Complutense de Madrid (projects: (PID2019-105306RB-I00 (IBER - CANES), CGL2016-78702 (SAFEFLIGHT), PCIN-2016-080 and FEI-EU-17-16)Publicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL
Sedimentary thickness distribution in the Protector and Pirie basins (Scotia Sea, Antarctica): control factors
Se ha realizado un análisis de estratigrafía sísmica mediante perfiles sísmicos
de reflexión multicanal en las cuencas de Protector y Pirie, las cuales
están ubicadas en el en el Mar de Scotia meridional, en las proximidades
del límite de placas Scotia-Antártica. Mediante este análisis se ha determinado
la distribución de los deposcentros sedimentarios más importantes, lo
que ha permitido comprobar que la distribución sedimentaria en dichas
cuencas está controlada por la morfoestructura del basamento e influenciada
por la distribución de las masas de agua profundas. Los resultados obtenidos
permiten establecer que ambas cuencas constituyen un buen ejemplo
de cuencas oceánicas profundas aisladas y desnutridas, sin aportes continentales
y bajo la influencia de corrientes de fondo activas relacionadas
con el Agua Profunda Circumpolar Antártica (CDW) y con el Agua Profunda
procedente del Mar de Weddell (WSDW)The analysis of multichannel seismic profiles reveals that the distribution
of sedimentary depocenters within the Protector and Pirie basins of the
southern Scotia Sea, close to the Scotia-Antarctica plate boundary, is largely
due to the morpho-structural control of the basement and influenced by the
distribution of bottom currents. Both basins constituted a good example of
small isolated and undernourished deep basins, lacking major continental
inputs and under the influence of active bottom currents related to both the
Antarctic Circumpolar deep Water and the Weddell Sea Deep Wate
Aircraft icing: in‐cloud measurements and sensitivity to physical parameterizations
The prediction of supercooled cloud drops in the atmosphere is a basic tool for aviation safety, owing to their contact with and instant freezing on sensitive locations of the aircraft. One of the main disadvantages for predicting atmospheric icing conditions is the acquisition of observational data. In this study, we used in‐cloud microphysics measurements taken during 10 flights of a C‐212 research aircraft under winter conditions, during which we encountered 37 regions containing supercooled liquid water. To investigate the capability of the Weather Research and Forecasting model to detect regions containing supercooled cloud drops, we propose a multiphysics ensemble approach. We used four microphysics and two planetary boundary layer schemes. The Morrison parameterization yielded superior results, whereas the planetary boundary layer schemes were essential in evaluating the presence of liquid water content. The Goddard microphysics scheme best detected the presence of ice water content but tended to underestimate liquid water content.This research was carried out in the framework of the SAFEFLIGHT project, financed by MINECO (CGL2016‐78702) and LE240P18 project (Junta de Castilla y León)
Cuidados en el puerperio durante la Crisis sanitaria por CoVid-19
Introducción: la infección por el nuevo coronavirus COVID-19, es actualmente una emergencia de salud pública internacional y ha sido declarada pandemia por la OMS. Aún se desconocen ciertos datos sobre su etiopatogenia, surgiendo la necesidad de analizar la influencia de la enfermedad por coronavirus durante la etapa puerperal y sus conse-cuencias. Objetivo: sintetizar el conocimiento y las últimas recomendaciones disponibles acerca de los cuidados específicos durante el periodo del puerperio, en relación con la crisis sanitaria por COVID-19. Metodología: se llevó a cabo una búsqueda sistemática en la literatura científica para localizar los documentos de evidencia científica disponibles en las principales bases de datos referenciales: Pubmed, Biblioteca Cochrane y Science Direct. Resultados: la lactancia materna aporta numerosos beneficios al recién nacido, entre ellos, la protección frente a infecciones respiratorias como el coronavirus. Si el estado materno y neonatal lo permite, se recomienda promover la lactancia materna durante el periodo de riesgo infeccioso. La SEGO y la SETH recomiendan la administra-ción de heparina de bajo peso molecular a dosis profilácticas para evitar la enfermedad tromboembólica. La evidencia actual indica que el riesgo de transmisión a través de la lactancia materna al recién nacido es muy poco probable. Discusión/conclusiones: la limitación principal fue la escasez de literatura científica sobre el COVID-19 en relación con el periodo puerperal. Es fundamental que cualquier puérpera con una infección por COVID-19 y su recién nacido sean valorados de manera individualizada, precozmente y evaluada por un equipo multidisciplinar para prevenir resultados adversosIntroduction: the new coronavirus COVID-19 infection is currently an international pu-blic health emergency and it has been declared a pandemic by the WHO. Certain data about its etiopathogenesis is still unknown, arising the need to analyse the influence of coronavirus disease during the puerperal stage and its consequences. Objective:to synthesize the knowledge and the latest available recommendations about specific care during puerperium period, related to the health crisis due to COVID-19. Methodo-logy: a systematic search was carried out in the scientific literature in order to locate the scientific evidence documents available in the main reference databases: PubMed, Cochrane Library and Science Direct. Results: breastfeeding brings many benefits to newborns, including protection against respiratory infections, such as coronavirus. If maternal and neonatal status allows it, it is recommended promoting breastfeeding during the infectious risk period. Both SEGO and SETH recommend the administration of low molecular weight heparin at prophylactic doses in order to avoid thromboembolic disease. Discussion/conclusions: the main limitation was the paucity of scientific lite-rature about COVID-19 in relation to puerperal period. It is essential that any puerperal woman with COVID-19 infection and her newborn are assessed individually, early and evaluated by a multidisciplinary team to prevent adverse outcome
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