325 research outputs found
The urban heat island of the Metropolitan City of Turin. Strategies for a sustainable urban planning
Globally, the world population living in cities is increasing and then the sustainability and liveability of urban spaces are rising the attention of the scientific community mainly in term of warming increase and health risk. In this work, the microclimate of outdoor spaces is investigated considering the different outdoor air temperatures registered by various weather stations in the city of Turin (Italy) and its surroundings with 12 municipalities. The air temperature variations are correlated with the built urban morphology, the solar exposure of urban spaces, the albedo coefficients of outdoor surfaces and other variables as the percentage of vegetation and water, the distance from the town centre and the Land Surface Temperature. With a multiple linear regression analysis the air temperatures have been correlated with the urban variables to obtain a simple model for the prediction of the average monthly air temperature in the Metropolitan City of Turin. This model can be used to understand the different microclimates within Turin and between the urban and the rural areas, and to evaluate the most influential variables on the air temperature variations. The resulted models could help urban planners to predict the microclimate in new districts, but also in the existent ones, as a function of the urban form and of the outdoor materials chosen to mitigate the UHI phenomenon
Posibilidades lignitíferas de la cuenca Neógena de Ademuz (Fosa de Teruel)
La cuenca Terciaria de Ademuz es una cuenca intramontañosa-finialpídica colmatada por sedimentos del Mioceno-Plioceno. Se han distinguido cinco unidades litoestratigráficas en los sedimentos terciarios, de las cuales la Unidad Blanca Inferior presenta cierto interés en cuanto a posibilidades lignitíferas. Corresponde esta Unidad a un ambiente lacustre, en el que se depositan dos tipos de facies: Una travertínica, indicadora de un medio palustre muy somero, con abundante vegetación y condiciones oxidantes, y otra de ambiente tipo charca, que corresponde a un medio con lámina de agua escasa, pero mayor que en el caso anterior, con aguas tranquilas y condiciones reductoras, que son las idóneas para la acumulación de restos vegetales y formación de carbón. Las facies de último tipo predominan en dos zonas telmáticas, situadas al abrigo de islas interiores o en zonas marginales, en ambos casos protegidas de los aportes terrígenos, pero fuera de la zona de deposición de sedimentos exclusivamente lacustres, que se corresponden con las zonas de mayor cantidad de indicios de lignito
Efficient Anodically Grown WO3 for Photoelectrochemical Water Splitting
Abstract The potentiostatic anodization of metallic tungsten has been investigated in different solvent/electrolyte compositions with the aim of improving the photoelectrochemical performances of the tungsten oxide layer. Among the explored electrolytes, the anodization in the NMF/H2O/NH4F solvent mixture was found to produce the most efficient WO3 photoanodes, which, combining spectral sensitivity, high electrochemically active surface and improved charge transfer kinetics, outperform, under simulated solar illumination, most of the reported nanocrystalline substrates produced by anodization in aqueous electrolytes and by sol gel methods. While the preparation of the photoelectrodes is a slow process at room temperature (20 °C), it could be greatly accelerated (x 10) by carrying out the anodization at 40-50 °C, thus proving to be a fast and convenient approach to the production of high performing WO3 photoactive substrates directly connected to a metal electron collector
Thoracic surgery in the COVID-19 era: an Italian university hospital experience
BackgroundAims of this study were to assess the results of anti-COVID19 measures applied to maintain thoracic surgery activity at an Italian University institution through a 12-month period and to assess the results as compared with an equivalent non-pandemic time span.MethodsData and results of 646 patients operated on at the department of Thoracic Surgery of the Tor Vergata University Policlinic in Rome between February 2019 and March 2021 were retrospectively analyzed. Patients were divided in 2 groups: one operated on during the COVID-19 pandemic (pandemic group) and another during the previous non-pandemic 12 months (non-pandemic group). Primary outcome measure was COVID-19 infection-free rate.ResultsThree patients developed mild COVID-19 infection early after surgery resulting in an estimated COVID-19 infection-free rate of 98%. At intergroup comparisons (non-pandemic vs. pandemic group), a greater number of patients was operated before the pandemic (352 vs. 294, p = 0.0013). In addition, a significant greater thoracoscopy/thoracotomy procedures rate was found in the pandemic group (97/151 vs. 82/81, p = 0.02) and the total number of chest drainages (104 vs. 131, p = 0.0001) was higher in the same group. At surgery, tumor size was larger (19.5 13 vs. 28.2 +/- 21; p < 0.001) and T3-T4/T1-T2 ratio was higher (16/97 vs. 30/56; p < 0.001) during the pandemic with no difference in mortality and morbidity. In addition, the number of patients lost before treatment was higher in the pandemic group (8 vs. 15; p = 0.01). Finally, in 7 patients admitted for COVID-19 pneumonia, incidental lung (N = 5) or mediastinal (N = 2) tumors were discovered at the chest computed tomography.Conclusions Estimated COVID-19 infection free rate was 98% in the COVID-19 pandemic group; there were less surgical procedures, and operated lung tumors had larger size and more advanced stages than in the non-pandemic group. Nonetheless, hospital stay was reduced with comparable mortality and morbidity. Our study results may help implement efficacy of the everyday surgical care
Orexin-A/Hypocretin-1 Controls the VTA-NAc Mesolimbic Pathway via Endocannabinoid-Mediated Disinhibition of Dopaminergic Neurons in Obese Mice
Disinhibition of orexin-A/hypocretin-1 (OX-A) release occurs to several output areas of the lateral hypothalamus (LH) in the brain of leptin knockout obese ob/ob mice. In this study, we have investigated whether a similar increase of OX-A release occurs to the ventral tegmental area (VTA), an orexinergic LH output area with functional effects on dopaminergic signaling at the mesolimbic circuit. By confocal and correlative light and electron microscopy (CLEM) morphological studies coupled to molecular, biochemical, and pharmacological approaches, we investigated OX-A-mediated dopaminergic signaling at the LH-VTA-nucleus accumbens (NAc) pathway in obese ob/ob mice compared to wild-type (wt) lean littermates. We found an elevation of OX-A trafficking and release to the VTA of ob/ob mice and consequent orexin receptor-1 (OX1R)-mediated over-activation of dopaminergic (DA) neurons via phospholipase C (PLC)/diacylglycerol lipase (DAGL-α)-induced biosynthesis of the endocannabinoid 2-arachidonoylglycerol (2-AG). In fact, by retrograde signaling to cannabinoid receptor type 1 (CB1R) at inhibitory inputs to DA neurons, 2-AG inhibited GABA release thus inducing an increase in DA concentration in the VTA and NAc of ob/ob mice. This effect was prevented by the OX1R antagonist SB-334867 (30 mg/Kg, i.p.), or the CB1R antagonist AM251 (10 mg/Kg, i.p.) and mimicked by OX-A injection (40 μg/Kg, i.p.) in wt lean mice. Enhanced DA signaling to the NAc in ob/ob mice, or in OX-A-injected wt mice, was accompanied by β-arrestin2-mediated desensitization of dopamine D2 receptor (D2R) in a manner prevented by SB-334867 or the D2R antagonist L741 (1.5 mg/Kg, i.p.). These results further support the role of OX-A signaling in the control of neuroadaptive responses, such as compulsive reward-seeking behavior or binge-like consumption of high palatable food, and suggest that aberrant OX-A trafficking to the DA neurons in the VTA of ob/ob mice influences the D2R response at NAc, a main target area of the mesolimbic pathway, via 2-AG/CB1-mediated retrograde signaling
Impactos sobre las zonas costeras
Los principales problemas del cambio climático en las zonas costeras se relacionan con
potenciales cambios en la frecuencia y/o intensidad de las tormentas asi coma con el posible
ascenso del nivel media del mar (NMM). En cuanto al nivel del mar, las previsiones del IPCC
para fin de siglo se han ido reduciendo según disponía de datas mas fiables desde 50-90 cm
(IPCC 1998) a 1 3-68 cm (IPCC 2001). Los valores de INQUA (International Union for the Study
of Quaternary Sea-Level Change and Coastal Evolution Commission) y del IGCP (International
Geosciences Programme Projects 369 and 437) son aun mas modestos: 1 0-20 cm.
Para las costas del E y S de Esparia los datos disponibles indican una tendencia generalizada
de estabilidad 0 ligero descenso del NMM, aunque localmente la subsidencia pueda
enmascarar este efecta (por ejemplo delta del Ebro). Esta tendencia se manifiesta en
progradación costera crecimiento de flechas litorales relleno de estuarios y desaparición de
humedales. Par el contrario en la costa N los datos indican una tendencia al ascenso con tasas
de 3-4 mm/año en la segunda mitad del siglo 20. Esto se une a observaciones concretas que
muestran una reducción marcada de muchas playas confinadas retroceso de frentes dunares y
acantilados "blandos" 0 adelgazamiento y/o rotura de flechas litorales dificilmente atribuibles a
reducción en el aporte de sedimentos dado que datos recientes indican al contrario aumentos
notables de la tasa de sedimentación en estuarios a 10 largo del siglo pasado.
Por otro lado diversos trabajos muestran que el NMM se situ6 casi 1 m por encima del actual
hace aproximadamente entre 5500 y 2000 arios en momentos en los que las condiciones
climaticas fueron similares a las que se esperan para finales del presente siglo.
A partir de esos datos se puede considerar que un ascenso de alrededof de 50 cm para finales
de slglo es un escenario razonab!e. Una hip6tesis pesimista bastante men os probable pero no
descartable seria un ascenso del orden de 1 m, correspondiente con el maximo de algunas
predicciones y con las niveles pasados antes indicados. Esta situaci6n parece bastame menos
probable en la costa S y E que en la N.
En el caso de una hipotetica subida generalizada del nivel medio del mar (NMM) mar, las zonas
mas vulnerables seran los deltas y playas confinadas o rigidizadas. La parte del litoral español formada por acantilados de rocas resistentes no presentan problemas especiales. Sin embargo hay un peligro potencial de estabilidad de las costas formadas por acantilados
constituidos por materiales incoherentes (no muy significativo). Especulando con el escenario
de 0.5 m de maxima ascenso posible en el Cantabrico oriental podria suponer la desaparición
del 40 % de las playas siempre y cuando no tenga lugar un aumento de la alimentación de
arena (natural o artificial) a esas playas. Un ascenso relativo del NMM de 0.50m sin respuesta
sedimentaria asociada supondría la desaparición de alrededor del 50% del delta del Ebro.
No obstante estimaciones mas precisas sobre la previsible evolución de este tipo de sistemas
litorales deberian tener en cuenta las variaciones en la altura e intensidad ,del oleaje y de la
marea meteorológica.
En las costas bajas (deltas humedales costeros y zonas de uso agrario o construidas en el
entorno de estuarios o en llanuras aluviales costeras), ese hipotetico ascenso del NMM podria
implicar una inundación de las mismas. En el Cantabrico oriental podría suponer la inundación
de parte de las zonas bajas estimada en 23.5 km2. En el Mediterraneo y Baleares y suponiendo
un maximo de 0.5 m, las zonas mas amenazadas aparte de los deltas ya mencionados (Ebro y
Llobregat) son la Manga del Mar Menor (unos 20 km), Las lagunas de Cabo de Gata (5 km) y en
el Golfo de Cadiz alrededor de 10 km de la costa de Doñana y unos 100 km2 de marismas.
Parte de esas zonas estan ocupadas por edificios o infraestructuras pero muchas de ellas tienen uso agricola o parque natural y podrían permitir la formación de nuevos humedales que
compensarian por desplazamiento la previsible perdida de los que sean anegados.
Es de senalar que adicionalmente a las impactos potenciales derivados del cambio climatico
otros facto res de origen antropico tales cama el aparte de sedimentos por los rlos y las obras
costeras son tambien cuantitativamente muy influyentes en la estabilidad del litoral a corto
plazo.
Coma estrategias preventivas 0 de adaptacion principales se recomienda actuar de inmediato
sabre los facto res humanos relacionados con la estabilidad del litoral. Entre estos merecen ser
destacados el mantenimiento de descarga y aportes solidos de los rios como saluci6n al
"origen" del problema (la falta de material sedimentario). Como solucion a las "sintomas" del
problema (retroceso o movilidad excesiva de la costa) pueden mencionarse la estabilización de
playas y dunas la construccion de obras para limitar la capacidad de transporte del oleaje
incidente y las aportaciones artificiales de sedimento. En otra categoría estan las actuaciones
para la protección de valores naturales (ordenacion rigurosa del territorio para asegurar el
mantenimiento y recuperación de zonas valiosas). Tambien se considera necesario delimitar e
inventariar las areas y elementos afectables por el ascenso del nivel del mar, el oleaje y la
marea a fin de definir donde aplicar estrategias de abandono y retroceso de proteccion.
Actuar sobre dichos factores contribuira en cualquier caso a paliar los futuros impactos del
cambio climatico independientemente de las incertidumbres asociadas a magnitud de los mismos
Artificial photosynthesis: photoanodes based on polyquinoid dyes onto mesoporous tin oxide surface
Dye-sensitized photoelectrochemical cells represent an appealing solution for artificial photosynthesis, aimed at the conversion of solar light into fuels or commodity chemicals. Extensive efforts have been directed towards the development of photoelectrodes combining semiconductor materials and organic dyes; the use of molecular components allows to tune the absorption and redox properties of the material. Recently, we have reported the use of a class of pentacyclic quinoid organic dyes (KuQuinone) chemisorbed onto semiconducting tin oxide as photoanodes for water oxidation. In this work, we investigate the effect of the SnO2 semiconductor thickness and morphology and of the dye-anchoring group on the photoelectrochemical performance of the electrodes. The optimized materials are mesoporous SnO2 layers with 2.5 mu m film thickness combined with a KuQuinone dye with a 3-carboxylpropyl-anchoring chain: these electrodes achieve light-harvesting efficiency of 93% at the maximum absorption wavelength of 533 nm, and photocurrent density J up to 350 mu A/cm(2) in the photoelectrochemical oxidation of ascorbate, although with a limited incident photon-to-current efficiency of 0.075%. Calculations based on the density functional theory (DFT) support the role of the reduced species of the KuQuinone dye via a proton-coupled electron transfer as the competent species involved in the electron transfer to the tin oxide semiconductor. Finally, a preliminary investigation of the photoelectrodes towards benzyl alcohol oxidation is presented, achieving photocurrent density up to 90 mu A/cm(2) in acetonitrile in the presence of N-hydroxysuccinimide and pyridine as redox mediator and base, respectively. These results support the possibility of using molecular-based materials in synthetic photoelectrochemistry.[GRAPHICS]
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