21 research outputs found
Global urban environmental change drives adaptation in white clover
Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 nonâcritically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (nâ=â257), ARB (nâ=â248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; nâ=â10), or no RAS inhibitor (control; nâ=â264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ supportâfree days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ supportâfree days among critically ill patients was 10 (â1 to 16) in the ACE inhibitor group (nâ=â231), 8 (â1 to 17) in the ARB group (nâ=â217), and 12 (0 to 17) in the control group (nâ=â231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ supportâfree days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
Differential capacitance of the double layer at the electrode/ionic liquids interface
The differential capacitance of the electrical double layer at glassy carbon, platinum and gold electrodes immersed in various ionic liquids was measured using impedance spectroscopy. We discuss the influence of temperature, the composition of the ionic liquids and the electrode material on the differential capacitance/potential curves. For different systems these curves have various overall shapes, but all include several extremes and a common minimum near the open circuit potential. We attribute this minimum to the potential of zero charge (PZC). Significantly, the differential capacitance generally decreases if the applied potential is large and moving away from the PZC. This is attributed to lattice saturation [A. A. Kornyshev, J. Phys. Chem. B, 2007, 111, 5545] effects which result in a thicker double layer. The differential capacitance of the double layer grows and specific adsorption diminishes with increasing temperature. Specific adsorption of both cations and anions influences the shapes of curves close to the PZC. The general shape of differential capacitance/potential does not depend strongly on the identity of the electrode material.
Orientation and mutual location of ions at the surface of ionic liquids
The structure of the liquidâvacuum interface in room temperature ionic liquids (ILs) is investigated using angle-resolved X-ray photoelectron spectroscopy (ARXPS) and synchrotron X-ray photoelectron spectroscopy (SXPS). By varying the polar angle and comparing the results for the chosen ionic liquids, we identify the presence of a surface layer that is chemically different to the bulk. In particular, this layer: (i) is enriched by aliphatic carbon atoms from the saturated carbon chains of the anions and cations, and (ii) contains an unequal distribution of cations and anions in a direction normal to the surface. This unequal distribution creates a potential gradient which extends from the surface into the liquid. We show unequivocally that this layer is not due to the presence of impurities.
Recent Advances in Printed Thin-Film Batteries
The rapidly increasing demand for wearable electronic devices has motivated research in low-cost and flexible printed batteries with diverse form factors and architectures. In the past, technological achievements in the field have been emphasized, overlooking the industrial and market requirements. However, different applications require different battery chemistries and formats, that greatly impacts the manufacturing process and competition landscape. These chemistries and formats should therefore be selected carefully to maximize the chances for commercial success. As some of these technologies are starting to be marketed for portable electronics, there is a pressing need to evaluate different printing technologies and compare them in terms of the processing constraints and product requirements of specific electronic devices. By evaluating the intrinsic strengths and current limitations of printed battery technologies, development pathways can be prioritized, and potential bottlenecks can be overcome to accelerate the path to market
Structure of [C<sub>4</sub>mpyr][NTf<sub>2</sub>] Room-Temperature Ionic Liquid at Charged Gold Interfaces
The structure of 1-butyl-1-methylpyrrolidinium bisÂ(trifluoromethylsulfonyl)Âimide
([C<sub>4</sub>mpyr]Â[NTf<sub>2</sub>]) room-temperature ionic liquid
at an electrified gold interface was studied using neutron reflectometry,
cyclic voltammetry, and differential capacitance measurements. Subtle
differences were observed between the reflectivity data collected
on a gold electrode at three different applied potentials. Detailed
analysis of the fitted reflectivity data reveals an excess of [C<sub>4</sub>mpyr]<sup>+</sup> at the interface, with the amount decreasing
at increasingly positive potentials. A cation rich interface was found
even at a positively charged electrode, which indicates a nonelectrostatic
(specific) adsorption of [C<sub>4</sub>mpyr]<sup>+</sup> onto the
gold electrode
Structure of [C<sub>4</sub>mpyr][NTf<sub>2</sub>] Room-Temperature Ionic Liquid at Charged Gold Interfaces
The structure of 1-butyl-1-methylpyrrolidinium bisÂ(trifluoromethylsulfonyl)Âimide
([C<sub>4</sub>mpyr]Â[NTf<sub>2</sub>]) room-temperature ionic liquid
at an electrified gold interface was studied using neutron reflectometry,
cyclic voltammetry, and differential capacitance measurements. Subtle
differences were observed between the reflectivity data collected
on a gold electrode at three different applied potentials. Detailed
analysis of the fitted reflectivity data reveals an excess of [C<sub>4</sub>mpyr]<sup>+</sup> at the interface, with the amount decreasing
at increasingly positive potentials. A cation rich interface was found
even at a positively charged electrode, which indicates a nonelectrostatic
(specific) adsorption of [C<sub>4</sub>mpyr]<sup>+</sup> onto the
gold electrode
Structure of [C<sub>4</sub>mpyr][NTf<sub>2</sub>] Room-Temperature Ionic Liquid at Charged Gold Interfaces
The structure of 1-butyl-1-methylpyrrolidinium bisÂ(trifluoromethylsulfonyl)Âimide
([C<sub>4</sub>mpyr]Â[NTf<sub>2</sub>]) room-temperature ionic liquid
at an electrified gold interface was studied using neutron reflectometry,
cyclic voltammetry, and differential capacitance measurements. Subtle
differences were observed between the reflectivity data collected
on a gold electrode at three different applied potentials. Detailed
analysis of the fitted reflectivity data reveals an excess of [C<sub>4</sub>mpyr]<sup>+</sup> at the interface, with the amount decreasing
at increasingly positive potentials. A cation rich interface was found
even at a positively charged electrode, which indicates a nonelectrostatic
(specific) adsorption of [C<sub>4</sub>mpyr]<sup>+</sup> onto the
gold electrode
Structure of [C<sub>4</sub>mpyr][NTf<sub>2</sub>] Room-Temperature Ionic Liquid at Charged Gold Interfaces
The structure of 1-butyl-1-methylpyrrolidinium bisÂ(trifluoromethylsulfonyl)Âimide
([C<sub>4</sub>mpyr]Â[NTf<sub>2</sub>]) room-temperature ionic liquid
at an electrified gold interface was studied using neutron reflectometry,
cyclic voltammetry, and differential capacitance measurements. Subtle
differences were observed between the reflectivity data collected
on a gold electrode at three different applied potentials. Detailed
analysis of the fitted reflectivity data reveals an excess of [C<sub>4</sub>mpyr]<sup>+</sup> at the interface, with the amount decreasing
at increasingly positive potentials. A cation rich interface was found
even at a positively charged electrode, which indicates a nonelectrostatic
(specific) adsorption of [C<sub>4</sub>mpyr]<sup>+</sup> onto the
gold electrode