Molecular excitation in the Interstellar Medium: recent advances in collisional, radiative and chemical processes

We review the different excitation processes in the interstellar mediumComment: Accepted in Chem. Re

Probing the Gravitational Dependence of the Fine-Structure Constant from Observations of White Dwarf Stars

Hot white dwarf stars are the ideal probe for a relationship between the fine-structure constant and strong gravitational fields, providing us with an opportunity for a direct observational test. We study a sample of hot white dwarf stars, combining far-UV spectroscopic observations, atomic physics, atmospheric modelling, and fundamental physics in the search for variation in the fine structure constant. This variation manifests as shifts in the observed wavelengths of absorption lines, such as quadruply ionized iron (FeV) and quadruply ionized nickel (NiV), when compared to laboratory wavelengths. Berengut et al. (Phys. Rev. Lett. 2013, 111, 010801) demonstrated the validity of such an analysis using high-resolution Space Telescope Imaging Spectrograph (STIS) spectra of G191-B2B. We have made three important improvements by: (a) using three new independent sets of laboratory wavelengths; (b) analysing a sample of objects; and (c) improving the methodology by incorporating robust techniques from previous studies towards quasars (the Many Multiplet method). A successful detection would be the first direct measurement of a gravitational field effect on a bare constant of nature. Here we describe our approach and present preliminary results from nine objects using both FeV and NiV.This project is funded by a Leverhulme Trust Research Grant. WULTB wishes to acknowledge support from the LABEX Plas@par managed by the French ANR (ANR-11-IDEX-0004-02). J.D. Barrow is supported by the STFC of the UK

Effect of semaglutide 2.4 mg on use of antihypertensive and lipid-lowering treatment in five randomized controlled STEP trials.

OBJECTIVE: The objective of this study was to assess antihypertensive and lipid-lowering treatment changes in participants receiving semaglutide 2.4 mg versus placebo across pooled populations from five Semaglutide Treatment Effect in People with Obesity (STEP) trials. METHODS: Efficacy and safety of semaglutide 2.4 mg were evaluated in the STEP clinical trials. In this post hoc analysis, STEP 1, 3, 6, and 8 (which included people with overweight or obesity) and, separately, STEP 2 and 6 (which included people with overweight or obesity and type 2 diabetes) were pooled for analysis. Changes in antihypertensive or lipid-lowering treatment intensity from randomization to end of treatment were evaluated. RESULTS: In both pooled samples, a higher proportion of participants in the semaglutide 2.4 mg group versus placebo underwent antihypertensive or lipid-lowering treatment intensity reduction by end of treatment. A smaller proportion underwent antihypertensive or lipid-lowering treatment intensification by end of treatment in the semaglutide 2.4 mg group of both samples versus placebo. In participants receiving antihypertensive or lipid-lowering medications in both samples, greater numeric reductions in body weight were observed in the semaglutide 2.4 mg group versus placebo. CONCLUSIONS: These results support a relationship between semaglutide 2.4 mg treatment of overweight and obesity and reduced need for antihypertensive and lipid-lowering treatment, facilitating treatment intensity reduction/discontinuation and abating treatment intensification.2026-01-0

Muscle blood volume assessment during exercise with Power Doppler Ultrasound

Assessment of perfusion adaptation in muscle during exercise can provide diagnostic information on cardiac and endothelial diseases. Power Doppler Ultrasound (PDUS) is known for its feasibility in the non-invasive measurement of moving blood volume (MBV), a perfusion related parameter. In this study, we show how PDUS can be used to assess the MBV kinetics in muscle, before, during, and after exercise. In a volunteer study, PDUS signal was obtained continuously on the gastrocnemius muscle and rectus femoris muscle, during calf raise (N=11) and leg extension exercises (N=11), respectively. To test reproducibility, the measurements were repeated on two different days. A clear increase of PDUS signal was obtained in both exercises. MBV kinetics during leg extension and after calf raise are assessed by linear and mono-exponential fitting of the data. The reproducibility of the obtained slope and time constants of the signal increase and decay were moderate to good between measurement days, with intra-class correlations (ICC) values of 0.6 - 0.8. Future studies will focus on protocol standardization and the monitoring of muscle perfusion during whole body exercise

Perfusion dynamics assessment with Power Doppler ultrasound in skeletal muscle during maximal and submaximal cycling exercise

Purpose: Assessment of limitations in the perfusion dynamics of skeletal muscle may provide insight in the pathophysiology of exercise intolerance in, e.g., heart failure patients. Power doppler ultrasound (PDUS) has been recognized as a sensitive tool for the detection of muscle blood flow. In this volunteer study (N = 30), a method is demonstrated for perfusion measurements in the vastus lateralis muscle, with PDUS, during standardized cycling exercise protocols, and the test–retest reliability has been investigated. Methods: Fixation of the ultrasound probe on the upper leg allowed for continuous PDUS measurements. Cycling exercise protocols included a submaximal and an incremental exercise to maximal power. The relative perfused area (RPA) was determined as a measure of perfusion. Absolute and relative reliability of RPA amplitude and kinetic parameters during exercise (onset, slope, maximum value) and recovery (overshoot, decay time constants) were investigated. Results: A RPA increase during exercise followed by a signal recovery was measured in all volunteers. Amplitudes and kinetic parameters during exercise and recovery showed poor to good relative reliability (ICC ranging from 0.2–0.8), and poor to moderate absolute reliability (coefficient of variation (CV) range 18–60%). Conclusions: A method has been demonstrated which allows for continuous (Power Doppler) ultrasonography and assessment of perfusion dynamics in skeletal muscle during exercise. The reliability of the RPA amplitudes and kinetics ranges from poor to good, while the reliability of the RPA increase in submaximal cycling (ICC = 0.8, CV = 18%) is promising for non-invasive clinical assessment of the muscle perfusion response to daily exercise

Far UV transitions involving high electronic states of the H2 molecule

International audienc