CRISP Spectropolarimetric Imaging of Penumbral Fine Structure

We discuss penumbral fine structure in a small part of a pore, observed with the CRISP imaging spectropolarimeter at the Swedish 1-m Solar Telescope (SST), close to its diffraction limit of 0.16 arcsec. Milne-Eddington inversions applied to these Stokes data reveal large variations of field strength and inclination angle over dark-cored penumbral intrusions and a dark-cored light bridge. The mid-outer part of this penumbra structure shows 0.3 arcsec wide spines, separated by 1.6 arcsec (1200 km) and associated with 30 deg inclination variations. Between these spines, there are no small-scale magnetic structures that easily can be be identified with individual flux tubes. A structure with nearly 10 deg more vertical and weaker magnetic field is seen midways between two spines. This structure is co-spatial with the brightest penumbral filament, possibly indicating the location of a convective upflow from below.Comment: Accepted for publication in ApJL 17 Oct 2008. One Figure adde

Atmospheric sink of styrene, α-methylstyrene, trans-β-methylstyrene and indene: Rate constants and mechanisms of the Cl atoms initiated degradation

The kinetics and products of the oxidation of four aromatic compounds, i.e. styrene, α-methylstyrene, trans-β-methylstyrene and indene, with Cl atoms were determined at atmospheric pressure and room temperature. Kinetic experiments were carried out in a 400 L Teflon reaction chamber using GC-FID for the analysis of reactants and products were determined using a 56 L quartz-glass reactor coupled to FTIR spectrophotometer. The rate constants at 298 K, using different reference compounds, were (in units of cm3 molecule−1 s−1): kstyrene = (1.29 ± 0.52)×10−10, kα-methylstyrene = (1.55 ± 0.27)×10−10, ktrans-β-methylstyrene = (1.09 ± 0.23)×10−10 and kindene = (1.01 ± 0.30)×10−10. Observations with FTIR suggest that the main reaction is the addition of the Cl to the aliphatic chain of the aromatic molecules. We found benzaldehyde, benzoyl chloride, formaldehyde and formyl chloride from styrene; acetophenone, formaldehyde and formyl chloride from α-methylstyrene; and benzaldehyde, formaldehyde and acetyl chloride from trans-β-methylstyrene as the main oxidation products. DFT theoretical calculations were performed in order to shed light on the identification of the reaction products. To the best of our knowledge, this work represents the first determination of the rate coefficients and products for the reaction of the Cl atoms with these compounds, except for the rate constant of styrene which has been studied previously. The loss processes of the title compounds in the atmosphere are mostly controlled by reactions with OH radicals during the day and with NO3 at night, but in coastal areas and some polluted environments, Cl reactions became comparable with OH and NO3 radicals, with lifetimes of 2.2 h for styrene, 1.8 h for AMS, 2.5 h for TBMS and 2.8 h for indene

Formation of secondary aerosols from the ozonolysis of styrene: effect of SO2 and H2O.

In this work we report the study of the ozonolysis of styrene and the reaction conditions leading to the formation of secondary aerosols. The reactions have been carried out in a Teflon chamber filled with synthetic air mixtures at atmospheric pressure and room temperature. We have found that the ozonolysis of styrene in the presence of low concentrations of SO2 readily produces new particles under concentrations of reactants lower than those required in experiments in the absence of SO2. Thus, nucleation events occur at concentrations around (5.6 ± 1.7) × 108molecule cm−3 (errors are 2σ±20%) and SO2 is consumed during the experiments. The reaction of the Criegee intermediates with SO2 to produce SO3 and then H2SO4 may explain (together with OH reactions’ contribution) the high capacity of styrene to produce particulate matter in polluted atmospheres. The formation of secondary aerosols in the smog chamber is inhibited under high H2O concentrations. So, the potential formation of secondary aerosols under atmospheric conditions depends on the concentration of SO2 and relative humidity, with a water to SO2 rate constants ratio kH2O/kSO2 = (2.8 ± 0.7) × 10−5 (errors are 2σ±20%)

What do we evaluate in sport mindfulness interventions? A systematic review of commonly used questionnaires

Interest of the study: mindfulness is a concept describing the focus on the present moment, intentionally and without judgement. This approach has only recently been applied to sport psychology. Objectives: the aim of the current review is to investigate which indicators and questionnaires are used in mindfulness research in sport, being specifically interested in mindfulness assessment. Methods: PRISMA guidelines for systematic reviews and the recommendations of the Cochrane Collaboration were used. Literature searches were conducted in Psychinfo, PubMed, EMBASE and the Cochrane Library. Results: From 2, 203 records initially retrieved, 17 articles were included. The results show that mindfulness, anxiety and acceptance are the most commonly studied psychological indicators. The Five Facet Mindfulness Questionnaire is the most frequently used mindfulness scale. We also discuss the possibility of using physiological indicators as complementary assessment. Conclusions: It is recommended to specifically adapt some questionnaires, such is already done with the Sport Anxiety Scale or the Mindfulness Inventory for Sport, for their use in sport psychology

Pd-(L)1 inhibitors as monotherapy for the first-line treatment of non-small-cell lung cancer patients with high pd-l1 expression : A network meta-analysis

Altres ajuts: RocheProgrammed cell death-ligand 1 (PD-L1) has emerged as a potential biomarker for selec-tion of patients more likely to respond to immunotherapy and as a prognostic factor in non-small cell lung cancer (NSCLC). In this network meta-analysis, we aimed to evaluate the efficacy of first-line anti-PD-(L)1 monotherapy in advanced NSCLC patients with high PD-L1 expression (≥50%) compared to platinum-based chemotherapy. We also evaluated efficacy outcomes according to tumor mutational burden (TMB). To that end, we conducted a systematic review. Six clinical trials with 2111 patients were included. In head-to-head comparisons, immunotherapy showed a significant improvement in progression-free survival (PFS: HRpooled = 0.69, 95% CI: 0.52-0.90, p = 0.007), overall survival (OS: HRpooled = 0.69, 95% CI: 0.61-0.78; p < 0.001) and overall response rate (ORR) (Risk ratio (RR)pooled = 1.354, 95% CI: 1.04-1.762, p = 0.024). In the assessment of relative efficacy for PFS through indirect comparisons, pembrolizumab (results from KEYNOTE-024) ranked highest followed by cemiplimab and atezolizumab, with statistical significance determined for some of the drugs. In terms of OS, cemiplimab ranked highest followed by atezolizumab and pembrolizumab, although non-significant OS was determined for these drugs. In conclusion, PD-(L)1 inhibitor mon-otherapy improves efficacy outcomes in the first line setting of advanced NSCLC patients with high PD-L1 expression. Evaluations with longer follow up are still needed to determine the superiority of any specific drug

Design and characterization of a magneto-dielectric composite in high frequency with aligned magnetite powders

A magneto-dielectric material composed of a polyester resin-based microstrip (P115A), copper sheets and magnetite powders was designed in concentrations of 10, 20 and 30% Wt and with filters of 200, 325 and 500. The particles were aligned vertically and horizontally during the curing process using 300 mT magnetic fields. From a complete factorial design of 33, 27 microstrip-type circuits of 4 mm width, 70 mm length and 0.93 mm thickness were manufactured, characterized by scanning electron microscopy and vector network analysis. The cross-matrix analysis determined an optimal circuit response from the magneto-dielectric material with a concentration of 20% magnetite and an average particle size of 21.48 μm in horizontal alignment to the applied magnetic field and to the transmission line, obtaining a relative dielectric constant of Er 3.88 with a low dielectric loss of 0.054, within an operating range of 150 KHz to 4 GHz

Heterogeneity of melanoma cell responses to sleep apnea-derived plasma exosomes and to intermittent hypoxia

Obstructive sleep apnea (OSA) is associated with increased cutaneous melanoma incidence and adverse outcomes. Exosomes are secreted by most cells, and play a role in OSA-associated tumor progression and metastasis. We aimed to study the effects of plasma exosomes from OSA patients before and after adherent treatment with continuous positive airway pressure (CPAP) on melanoma cells lines, and also to identify exosomal miRNAs from melanoma cells exposed to intermittent hypoxia (IH) or normoxia. Plasma-derived exosomes were isolated from moderate-to-severe OSA patients before (V1) and after (V2) adherent CPAP treatment for one year. Exosomes were co-incubated with three3 different melanoma cell lines (CRL 1424; CRL 1619; CRL 1675) that are characterized by genotypes involving different mutations in BRAF, STK11, CDKN2A, and PTEN genes to assess the effect of exosomes on cell proliferation and migration, as well as on pAMK activity in the presence or absence of a chemical activator. Subsequently, CRL-1424 and CRL-1675 cells were exposed to intermittent hypoxia (IH) and normoxia, and exosomal miRNAs were identified followed by GO and KEG pathways and gene networks. The exosomes from these IH-exposed melanoma cells were also administered to THP1 macrophages to examine changes in M1 and M2 polarity markers. Plasma exosomes from V1 increased CRL-1424 melanoma cell proliferation and migration compared to V2, but not the other two cell lines. Exposure to CRL-1424 exosomes reduced pAMPK/tAMPK in V1 compared to V2, and treatment with AMPK activator reversed the effects. Unique exosomal miRNAs profiles were identified for CRL-1424 and CRL-1675 in IH compared to normoxia, with six miRNAs being regulated and several KEGG pathways were identified. Two M1 markers (CXCL10 and IL6) were significantly increased in monocytes when treated with exosomes from IH-exposed CRL-1424 and CRL-1625 cells. Our findings suggest that exosomes from untreated OSA patients increase CRL-1424 melanoma malignant properties, an effect that is not observed in two other melanoma cell lines. Exosomal cargo from CRL-1424 cells showed a unique miRNA signature compared to CRL-1675 cells after IH exposures, suggesting that melanoma cells are differentially susceptible to IH, even if they retain similar effects on immune cell polarity. It is postulated that mutations in STK-11 gene encoding for the serine/threonine kinase family that acts as a tumor suppressor may underlie susceptibility to IH-induced metabolic dysfunction, as illustrated by CRL-1424 cells. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Beyond Eliashberg superconductivity in MgB2: anharmonicity, two-phonon scattering, and multiple gaps

Density-functional calculations of the phonon spectrum and electron-phonon coupling in MgB$_2$ are presented. The $E_{2g}$ phonons, which involve in-plane B displacements, couple strongly to the $p_{x,y}$ electronic bands. The isotropic electron-phonon coupling constant is calculated to be about 0.8. Allowing for different order parameters in different bands, the superconducting $\lambda$ in the clean limit is calculated to be significantly larger. The $E_{2g}$ phonons are strongly anharmonic, and the non-linear contribution to the coupling between the $E_{2g}$ modes and the p$_{x,y}$ bands is significant.Comment: 4 pages, 3 figure

The role of extracellular matrix on liver stem cell fate: A dynamic relationship in health and disease

The liver stem cell niche is a specialized and dynamic microenvironment with biomechanical and biochemical characteristics that regulate stem cell behavior. This is feasible due to the coordination of a complex network of secreted factors, small molecules, neural, blood inputs and extracellular matrix (ECM) components involved in the regulation of stem cell fate (self-renewal, survival, and differentiation into more mature phenotypes like hepatocytes and cholangiocytes). In this review, we describe and summarize all the major components that play essential roles in the liver stem cell niche, in particular, growth factor signaling and the biomechanical properties of the ECM