Isobutyl acetate: electronic state spectroscopy by high-resolution vacuum ultraviolet photoabsorption, He(I) photoelectron spectroscopy and ab initio calculations

The high-resolution vacuum ultraviolet photoabsorption spectrum of isobutyl acetate, C6H12O2, is presented here and was measured over the energy range 4.3–10.8 eV (290–115 nm). Valence and Rydberg transitions with their associated vibronic series have been observed in the photoabsorption spectrum and are assigned in accordance with new ab initio calculations of the vertical excitation energies and oscillator strengths. The measured photoabsorption cross sections have been used to calculate the photolysis lifetime of this ester in the Earth’s upper atmosphere (20–50 km). Calculations have also been carried out to determine the ionization energies and fine structure of the lowest ionic state of isobutyl acetate and are compared with a photoelectron spectrum (from 9.5 to 16.7 eV), recorded for the first time. Vibrational structure is observed in the first photoelectron band of this molecule

Olive oil consumption and all-cause, cardiovascular and cancer mortality in an adult mediterranean population in Spain

Objective: We assessed the association between usual olive oil consumption (OOC) and all-cause, cardiovascular (CVD) and cancer mortality in an adult population in Spain. Materials and methods: OOC was evaluated at baseline in 1,567 participants aged 20 years and older from the Valencia Nutrition Study in Spain using validated food frequency questionnaires. During an 18-year follow-up period, 317 died, 115 due to CVD and 82 due to cancer. Cox regression models were used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (95%CI). Results: After adjusting for demographic and lifestyle factors, the OOC was associated with a lower risk of all-cause, CVD and cancer mortality. Compared to the less than once per month consumption, the consumption of up to one tablespoon per day was associated with a 9% lower risk of all-cause mortality (HR: 0.91; 95%CI: 0.68-1.22) and the consumption of 2 or more tablespoons with a 31% lower risk of all-cause mortality (HR: 0.69; 95%CI: 0.50–0.93; p-trend = 0.011). The consumption of 2 or more tablespoons per day was also associated with lower risk of mortality for CVD (HR: 0.54; 95%CI: 0.32–0.91; p-trend = 0.018) and cancer (HR: 0.49, 95%CI: 0.26–0.94; p-trend = 0.019). Conclusion: Higher olive oil consumption was associated with lower long-term risk of all-cause, CVD and cancer mortality in an adult Mediterranean population. The maximum benefit was observed for the consumption of two or more tablespoons per day. Copyright © 2022 Torres-Collado, García-de la Hera, Lopes, Compañ-Gabucio, Oncina-Cánovas, Notario-Barandiaran, González-Palacios and Vioque.The VNS study was supported by a grant from the Dirección General de Salud Pública, Generalitat Valenciana 1994 and the Fondo Investigacion Sanitaria (FIS 00/0985). This study has also received support from the Instituto de Salud Carlos III FEDER funds (FIS PI13/00654), CIBER of Epidemiology and Public Health (CIBERESP), CB06/02/0013 and ISABIAL

Temperature Dependent Zero-Field Splittings in Graphene

Graphene is a quantum spin Hall insulator with a 45 $\mu$eV wide non-trivial topological gap induced by the intrinsic spin-orbit coupling. Even though this zero-field spin splitting is weak, it makes graphene an attractive candidate for applications in quantum technologies, given the resulting long spin relaxation time. On the other side, the staggered sub-lattice potential, resulting from the coupling of graphene with its boron nitride substrate, compensates intrinsic spin-orbit coupling and decreases the non-trivial topological gap, which may lead to the phase transition into trivial band insulator state. In this work, we present extensive experimental studies of the zero-field splittings in monolayer and bilayer graphene in a temperature range 2K-12K by means of sub-Terahertz photoconductivity-based electron spin resonance technique. Surprisingly, we observe a decrease of the spin splittings with increasing temperature. We discuss the origin of this phenomenon by considering possible physical mechanisms likely to induce a temperature dependence of the spin-orbit coupling. These include the difference in the expansion coefficients between the graphene and the boron nitride substrate or the metal contacts, the electron-phonon interactions, and the presence of a magnetic order at low temperature. Our experimental observation expands knowledge about the non-trivial topological gap in graphene.Comment: Main text with figures (20 pages) and Supplementary Information (14 pages) Accepted in Phys. Rev.

Voltage controlled sub-THz detection with gated planar asymmetric nanochannels

[EN]This letter reports on room temperature sub-THz detection using self-switching diodes based on an AlGaN/GaN heterostructure on a Si substrate. By means of free-space measurements at 300 GHz, we demonstrate that the responsivity and noise equivalent power (NEP) of sub-THz detectors based on planar asymmetric nanochannels can be improved and voltage controlled by means of a top gate electrode. A simple quasi-static model based on the DC measurements of the current-voltage curves is able to predict the role of the gate bias in its performance. The best values of voltage responsivity and NEP are achieved when the gate bias approaches the threshold voltage, around 600 V/W and 50 pW/Hz1/2, respectively. A good agreement is found between modeled results and those obtained from RF measurements under probes at low frequency (900MHz) and in free-space at 300 GHz

ERODIBILITY OF FOREST ANDOSOLS AND SOIL PROPERTIES

Abstract The sensitivity of Andosols to water erosion in a forest environment (Garajonay National Park, Gomera, Canary Islands) has been studied by evaluating USLE's erodibility factor (K), the actual susceptibility of soil to separation by means of two tests for measuring the stability of aggregates, and its relationship with relevant physicochemical properties. The results show the limited validity of the conventional estimation of erodibility in andic soils, where the sensitivity towards erosion is mostly related to their content in organometallic compounds

Differentiation stage of myeloma plasma cells: biological and clinical significance

[EN] The notion that plasma cells (PCs) are terminally differentiated has prevented intensive research in multiple myeloma (MM) about their phenotypic plasticity and differentiation. Here, we demonstrated in healthy individuals (n = 20) that the CD19 − CD81 expression axis identifies three bone marrow (BM)PC subsets with distinct age-prevalence, proliferation, replication-history, immunoglobulin-production, and phenotype, consistent with progressively increased differentiation from CD19+CD81+ into CD19 − CD81+ and CD19 − CD81 − BMPCs. Afterwards, we demonstrated in 225 newly diagnosed MM patients that, comparing to normal BMPC counterparts, 59% had fully differentiated (CD19 − CD81 −) clones, 38% intermediate-differentiated (CD19 − CD81+) and 3% less-differentiated (CD19+CD81+) clones. The latter patients had dismal outcome, and PC differentiation emerged as an independent prognostic marker for progression-free (HR: 1.7; P = 0.005) and overall survival (HR: 2.1; P = 0.006). Longitudinal comparison of diagnostic vs minimal-residual-disease samples (n = 40) unraveled that in 20% of patients, less-differentiated PCs subclones become enriched after therapy-induced pressure. We also revealed that CD81 expression is epigenetically regulated, that less-differentiated clonal PCs retain high expression of genes related to preceding B-cell stages (for example: PAX5), and show distinct mutation profile vs fully differentiated PC clones within individual patients. Together, we shed new light into PC plasticity and demonstrated that MM patients harbouring less-differentiated PCs have dismal survival, which might be related to higher chemoresistant potential plus different molecular and genomic profiles

Estimating PM 2.5 concentrations in Xi'an City using a generalized additive model with multi-source monitoring data

© 2015 Song et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Particulate matter with an aerodynamic diameter <2.5 μm (PM2.5) represents a severe environmental problem and is of negative impact on human health. Xi'an City, with a population of 6.5 million, is among the highest concentrations of PM2.5 in China. In 2013, in total, there were 191 days in Xi'an City on which PM2.5 concentrations were greater than 100 μg/m3. Recently, a few studies have explored the potential causes of high PM2.5 concentration using remote sensing data such as the MODIS aerosol optical thickness (AOT) product. Linear regression is a commonly used method to find statistical relationships among PM2.5 concentrations and other pollutants, including CO, NO2, SO2, and O3, which can be indicative of emission sources. The relationships of these variables, however, are usually complicated and non-linear. Therefore, a generalized additive model (GAM) is used to estimate the statistical relationships between potential variables and PM2.5 concentrations. This model contains linear functions of SO2 and CO, univariate smoothing non-linear functions of NO2, O3, AOT and temperature, and bivariate smoothing non-linear functions of location and wind variables. The model can explain 69.50% of PM2.5 concentrations, with R2 = 0.691, which improves the result of a stepwise linear regression (R2 = 0.582) by 18.73%. The two most significant variables, CO concentration and AOT, represent 20.65% and 19.54% of the deviance, respectively, while the three other gas-phase concentrations, SO2, NO2, and O3 account for 10.88% of the total deviance. These results show that in Xi'an City, the traffic and other industrial emissions are the primary source of PM2.5. Temperature, location, and wind variables also non-linearly related with PM2.5