84 research outputs found
Probing the chemical environment of 3-hydroxyflavone doped ormosils by a spectroscopic study of excited state intramolecular proton transfer
Abstract The spectroscopic properties of 3-hydroxyflavone (3-HF) molecules entrapped in films and in monoliths of sol–gel derived organically modified silicates (Ormosils) xerogels are studied by excitation and fluorescence spectroscopy as a function of the sol–gel precursors used for the synthesis. Different molar ratios of tetraethoxysilane (TEOS), methyltriethoxysilane (MTES) and phenyltriethoxysilane (PTES) as precursors are used for the sol preparation. Emission and excitation spectra in the ultraviolet–visible range and photo-degradation curves as a function of time are collected with a spectrofluorimeter. The 3-hydroxyflavone optical properties change in the different networks, owing to the effects of the chemical environment on the excited state intramolecular proton transfer and to the solubility of the dye molecules in the different sol–gel systems. It turns out that the spectroscopic features can be used to probe the chemical state of the dye molecules microenvironment
Facing complications of direct anterior approach in total hip arthroplasty during the learning curve
This study aims to evaluate complications and early postoperative clinical outcomes of direct anterior approach (DAA) in total hip arthroplasty (THA)
Episyenites within the Tauern Window metagranitoids: unpredictable?
The core of the Tauern tectonic window (Eastern Alps) consists of dominant pre-Alpine granitoids (∼ 295 Ma) that were metamorphosed and deformed during the Alpine orogenesis (at ∼ 30 Ma). Ductile deformation at peak conditions (550-600 ̊C and 0.5-0.7 GPa) was followed by cataclastic faulting (Pennacchioni and Mancktelow, 2007). Both deformation phases occurred in a fluid-rich environment with formation of veins filled with quartz-calcite-biotite-feldspar and quartz-chlorite-epidote-adularia-calcite, respectively. Faults are typically low displacement strike-slip structures (offset < 1m) organized in en-echelon arrays at different scales with a stepping geometry consistent with the sense of fault slip (e.g. left-stepping for dextral slip). Fault stepovers include pervasive fracturing dominated by a set of antithetic faults (Pennacchioni and Mancktelow, 2013). These faults were locally exploited by episyenitic alteration which represented the "last" event of fluid-rock interaction in the Tauern meta-granitoids. Episyenites within metagranodiorites have a macroscopic porosity in the range between 25 and 35% volume (determined by microtomography), mostly derived from dissolution of multi-mm-sized quartz. Recent glacier-polished outcrops provide a unique opportunity to investigate the relationships between episyenites and overprinted faults. Detailed field mapping of a selected outcrop indicates that episyenites: (i) are spatially linked to precursor faults and statically overprinted all previous structures; (ii) occur discontinuously along faults; (iii) have a thickness (of as much as a few meters) that does not correlate with either the amount of fault slip or the density of the fracture network; (iv) developed independently of rock type (passing "undisturbed" lithologic boundaries with conspicuous variations of quartz grain size of the protolith lithology). Although the faults in the studied outcrop are extensively decorated by relatively large volumes of episyenite, occurrences of episyenite in the Tauern granitoids are generally rare. This study indicates that there is not a simple way to predict the location and the extent of episyenite alteration from the geometry and fracturing patterns of the network of precursor cataclastic faults. The dominant quartz dissolution during episyenitization was accompanied and/or followed by: (i) pervasive substitution of oligoclase and chlorite/biotite of the metagranodiorite by albite and clay-minerals, respectively, and (ii) limited precipitation of new adularia, anatase, calcite, hematite and zeolite within pores. Isotopic data from calcite filling the episyenite porosity suggest a meteoric source of the fluids (δ18 O (SMOW) ≈ -2 per mil). In contrast, fluids synkinematic with previous episodes of fluid-rock interaction during faulting and ductile shearing had a deeper origin (δ18O (SMOW) ≈ 8-9 per mil). References Pennacchioni, G., Mancktelow, N.S., 2007. J. Struct. Geol. 29, 1757-1780. Pennacchioni, G., Mancktelow, N.S., 2013. Geol. Soc. Am. Bull. 125, 1468-1483
Individual Differences, Economic Stability, and Fear of Contagion as Risk Factors for PTSD Symptoms in the COVID-19 Emergency
On January 30th 2020, the World Health Organization (WHO) declared the COVID-19 pandemic a Public Health Emergency of International Concern (PHEIC). Italy has been one of the most affected countries in the world. To contain further spread of the virus, the Italian government has imposed an unprecedented long-period lockdown for the entire country. This dramatic scenario may have caused a strong psychological distress, with potential negative long-term mental health consequences. The aim of the present study is to report the prevalence of high psychological distress due to the COVID-19 pandemic on the general population, especially considering that this aspect is consistently associated with PTSD symptoms. Furthermore, the present study aims to identify the risk factors for high PTSD symptoms, including individual differences and subjective perception of both economic and psychological aspects. We administered an online survey to 1253 participants during the peak period of the contagion in Italy. A logistic regression on the Impact of Event Scale – Revised (IES-R) scores was used to test the risk factors that predict the possibility to develop PTSD symptoms due to the COVID-19 pandemic. Gender (female), lower perceived economic stability, higher neuroticism, and fear and consequences of contagion were predictors of high PTSD symptomatology. The results, highlighted in the present study, extend our understanding of the COVID-19 pandemic’s impact on the population’s mental health, by identifying individuals at high-risk of developing PTSD. This may help with the implementation of specific protocols to prevent the possibility of developing symptoms of PTSD in target populations
Psychological Factors and Consumer Behavior During the COVID-19 Pandemic
The COVID-19 pandemic is far more than a health crisis: it has unpredictably changed our whole way of life. As suggested by the analysis of economic data on sales, this dramatic scenario has also heavily impacted individuals’ spending levels. To better understand these changes, the present study focused on consumer behavior and its psychological antecedents. Previous studies found that crises differently affect people’s willingness to buy necessities products (i.e., utilitarian shopping) and non-necessities products (i.e., hedonic shopping). Therefore, in examining whether changes in spending levels were associated with changes in consumer behavior, we adopted a fine-grained approach disentangling between necessities and non-necessities. We administered an online survey to 3833 participants (age range 18–64) during the first peak period of the contagion in Italy. Consumer behavior toward necessities was predicted by anxiety and COVID-related fear, whereas consumer behavior toward non-necessities was predicted by depression. Furthermore, consumer behavior toward necessities and non-necessities was predicted by personality traits, perceived economic stability, and self-justifications for purchasing. The present study extended our understanding of consumer behavior changes during the COVID-19 pandemic. Results could be helpful to develop marketing strategies that consider psychological factors to meet actual consumers’ needs and feelings
Cardiac injury and mortality in patients with Coronavirus disease 2019 (COVID-19): insights from a mediation analysis
Patients at greatest risk of severe clinical conditions from coronavirus disease 2019 (COVID-19) and death are elderly and comorbid patients. Increased levels of cardiac troponins identify patients with poor outcome. The present study aimed to describe the clinical characteristics and outcomes of a cohort of Italian inpatients, admitted to a medical COVID-19 Unit, and to investigate the relative role of cardiac injury on in-hospital mortality
Ethylene negatively regulates transcript abundance of ROP-GAP rheostat-encoding genes and affects apoplastic reactive oxygen species homeostasis in epicarps of cold stored apple fruits
Apple (Malus
7domestica Borkh) fruits are stored for long periods of time at low temperatures (1 \ub0C) leading to the occurrence of physiological disorders. 'Superficial scald' of Granny Smith apples, an economically important ethylene-dependent disorder, was used as a model to study relationships among ethylene action, the regulation of the ROP-GAP rheostat, and maintenance of H2O2 homeostasis in fruits during prolonged cold exposure. The ROP-GAP rheostat is a key module for adaptation to low oxygen in Arabidopsis through Respiratory Burst NADPH Oxidase Homologs (RBOH)-mediated and ROP GTPase-dependent regulation of reactive oxygen species (ROS) homeostasis. Here, it was shown that the transcriptional expression of several components of the apple ROP-GAP machinery, including genes encoding RBOHs, ROPs, and their ancillary proteins ROP-GEFs and ROP-GAPs, is coordinately and negatively regulated by ethylene in conjunction with the progressive impairment of apoplastic H2O2 homeostatic levels. RNA sequencing analyses showed that several components of the known ROP- and ROS-associated transcriptional networks are regulated along with the ROP-GAP rheostat in response to ethylene perception. These findings may extend the role of the ROP-GAP rheostat beyond hypoxic responses and suggest that it may be a functional regulatory node involved in the integration of ethylene and ROS signalling pathways in abiotic stress
Activador Ruminal de elaboración Casera. Implementación de un suplemento nutricional casero para ovinos en campos de la Meseta Central Santacruceña
La planificación del pastoreo permite ajustar la carga animal para asà poder satisfacer los requerimientos de los ovinos a lo largo del año y no sobrepastorear el recurso forrajero (Fariña y col, 2019). Sin embargo, hay momentos crÃticos del ciclo productivo donde la calidad del pastizal natural no llega a cubrir las necesidades de los animales (Anchorena y col., 2001) o cuando se presentan contingencias naturales como las sequias, nevadas y cenizas donde el recurso forrajero no está disponible (Giraudo, 2011). En estos momentos, es donde la suplementación se presenta como una herramienta estratégica para estabilizar o mejorar los resultados productivos (Clifton, 2004). Si bien la suplementación estratégica en campos de meseta, en diversas categorÃas, ha sido validada, demostrando un efecto positivo en la mejora de los Ãndices productivos (Ceballos y col., 2013; Aguilar y col., 2008; Aguilar y Alvarez, 2016), presenta algunas limitantes al momento de su implementación tales como el costo de los insumos, la infraestructura necesaria (comederos, entre otros) y la logÃstica para distribuir el suplemento a campo bajo condiciones extensivas. Trabajos recientes (Aguilar y col., 2017), a pequeña y mediana escala, han demostrado la factibilidad de utilizar un nuevo tipo de suplemento nutricional, activador ruminal de elaboración casera (ARC), presentado en forma de bloques en momentos crÃticos del año donde la calidad del pastizal natural no llega a cubrir los requerimientos nutricionales de los animales. Este tipo de suplemento, de composición energético/proteica, favorece el desarrollo de la flora ruminal mejorando la degradación de la fibra de forrajes de baja calidad nutricional (Schacht y col., 1992; Galindo y col., 2017). El objetivo del presente trabajo fue evaluar la factibilidad de la implementación del ARC como un suplemento estratégico, en campos de la Meseta Central Santacruceña (MCS) a escala real de producción y su impacto en los Ãndices productivos y económicos.EEA Santa CruzFil: Aguilar, Marcelo Javier. Instituto Nacional de TecnologÃa Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz. Agencia de Extensión Rural San Julián; Argentina.Fil: Alvarez, Roberto Horacio. Instituto Nacional de TecnologÃa Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz. Agencia de Extensión Rural San Julián; Argentina.Fil: Andrade, Larry. Universidad Nacional de la Patagonia Austral. Unidad Académica San Julián; Argentina.Fil: Schorr, Alan Geoffrey. Instituto Nacional de TecnologÃa Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; ArgentinaFil: Ceccato, Diana Valeria. Instituto Nacional de TecnologÃa Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz. Agencia de Extensión Rural San Julián; Argentina.Fil: Bonil, Ricardo Nicolas. Instituto Nacional de TecnologÃa Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; ArgentinaFil: Andrade, Miguel Alberto. Instituto Nacional de TecnologÃa Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Andrade, Miguel Alberto. Universidad Nacional de la Patagonia Austral. Unidad Académica RÃo Gallegos; Argentina.Fil: Ceballos, Demian. Instituto Nacional de TecnologÃa Agropecuaria (INTA). Estación Experimental Agropecuaria Esquel; Argentina
Low-valence Znδ+ (0<2) single-atom material as highly efficient electrocatalyst for CO2 reduction
A nitrogen-stabilized single-atom catalyst containing low-valence zinc atoms (Znδ+-NC) is reported. It contains saturated four-coordinate (Zn-N4) and unsaturated three-coordinate (Zn-N3) sites. The latter makes Zn a low-valence state, as deduced from X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, electron paramagnetic resonance, and density functional theory. Znδ+-NC catalyzes electrochemical reduction of CO2 to CO with near-unity selectivity in water at an overpotential as low as 310 mV. A current density up to 1 A cm−2 can be achieved together with high CO selectivity of >95 % using Znδ+-NC in a flow cell. Calculations suggest that the unsaturated Zn-N3 could dramatically reduce the energy barrier by stabilizing the COOH* intermediate owing to the electron-rich environment of Zn. This work sheds light on the relationship among coordination number, valence state, and catalytic performance and achieves high current densities relevant for industrial applications
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