4 research outputs found
Presentation1_Causal effects of homocysteine levels on the components of sarcopenia: A two-sample mendelian randomization study.pdf
Background: Currently, it is unclear whether there is a causal association between genetically predicted plasma homocysteine (Hcy) levels and the risk of sarcopenia. We performed a Mendelian randomization (MR) study to assess the association between circulating Hcy levels and the components [grip strength, walking pace, and appendicular lean mass (ALM)] of sarcopenia.Methods: Independent single nucleotide polymorphisms (SNPs) significantly associated with plasma Hcy levels served as instrumental variables. Summary-level data regarding the components of sarcopenia. Were obtained from the UK Biobank. Inverse variance weighted (IVW) as the primary method was used for Mendelian randomization (MR) analysis. We also use four models, weighted median, MR-Egger regression, Maximum likelihood, and Penalised weighted median, as supplementary methods to IVW. The MR-Egger intercept test, Cochran’s Q test, and “leave-one-out” sensitivity analysis were performed to evaluate the horizontal pleiotropy, heterogeneities, and stability of the causal association between Hcy levels and the components of sarcopenia.Results: The IVW-MR analysis suggested significant negative associations of increased plasma Hcy levels with grip strength (right: effect = −0.036, SE = 0.032, p = 5.53E-4; left: effect = −0.045, SE = 0.010, p = 1.45E-5), walking pace (effect = −0.038, SE = 0.011, p = 3.18E-4), and ALM (effect = −0.058, 0.013, p = 1.03E-5). However, there were no significant associations of decreased plasma Hcy levels with grip strength (right: effect = 0.005, SE = 0.021, p = 0.82; left: effect = −0.006, SE = 0.014, p = 0.64), walking pace (effect = 0.01, 0.020, p = 0.61), or ALM (effect = -0.034, SE = 0.018, p = 0.06).The accuracy and robustness of these findings were confirmed by sensitivity tests.Conclusion: Increased circulating Hcy levels were associated with lower grip strength, slower walking pace, and decreased ALM.</p
On Nucleation Pathways and Particle Size Distribution Evolutions in Stratospheric Aircraft Exhaust Plumes with H<sub>2</sub>SO<sub>4</sub> Enhancement
Stratospheric aerosol injection (SAI) is proposed as
a means of
reducing global warming and climate change impacts. Similar to aerosol
enhancements produced by volcanic eruptions, introducing particles
into the stratosphere would reflect sunlight and reduce the level
of warming. However, uncertainties remain about the roles of nucleation
mechanisms, ionized molecules, impurities (unevaporated residuals
of injected precursors), and ambient conditions in the generation
of SAI particles optimally sized to reflect sunlight. Here, we use
a kinetic ion-mediated and homogeneous nucleation model to study the
formation of H2SO4 particles in aircraft exhaust
plumes with direct injection of H2SO4 vapor.
We find that under the conditions that produce particles of desired
sizes (diameter ∼200–300 nm), nucleation occurs in the
nascent (t T =
360–445 K), and dry (RH = 0.01–0.1%) plume and is predominantly
unary. Nucleation on chemiions occurs first, followed by neutral new
particle formation, which converts most of the injected H2SO4 vapor to particles. Coagulation in the aging and diluting
plumes governs the subsequent evolution to a narrow (σg = 1.3) particle size distribution. Scavenging by exhaust soot is
negligible, but scavenging by acid impurities or incomplete H2SO4 evaporation in the hot exhaust plume and enhanced
background aerosols can matter. This research highlights the need
to obtain laboratory and/or real-world experiment data to verify the
model prediction
LiTFSI-Free Hole Transport Materials for Robust Perovskite Solar Cells and Modules with High Efficiencies
Lithium
bis(trifluoromethane) sulfonamide (LiTFSI) and oxygen-doped
organic semiconductors have been frequently used to achieve record
power conversion efficiencies of perovskite solar cells (PSCs). However,
this conventional doping process is time-consuming and leads to poor
device stability due to the incorporation of Li ions. Herein, aiming
to accelerate the doping process and remove the Li ions, we report
an alternative p-doping process by mixing a new small-molecule organic
semiconductor, N2,N2,N7,N7-tetrakis (4-methoxyphenyl)-9-(4-(octyloxy) phenyl)-9H carbazole-2,7-diamine (labeled OH44) and its preoxidized form OH44+(TFSI–). With this method, a champion efficiency
of 21.8% has been achieved for small-area PSCs, which is superior
to the state-of-the-art EH44 and comparable with LiTFSI and oxygen-doped spiro-OMeTAD. Moreover, the stability of OH44-based PSCs
is improved compared with those of EH44, maintaining more than 85%
of its initial efficiency after aging in an ambient condition without
encapsulation for 1000 h. In addition, we achieved efficiencies of
14.7 and 12.6% for the solar modules measured with a metal mask of
12.0 and 48.0 cm2, respectively, which demonstrated the
scalability of this method
Compositional Constraints are Vital for Atmospheric PM<sub>2.5</sub> Source Attribution over India
India experiences some of the highest levels of ambient
PM2.5 aerosol pollution in the world. However, due to the
historical
dearth of in situ measurements, chemical transport models that are
often used to estimate PM2.5 exposure over the region are
rarely evaluated. Here, we conduct a novel model comparison with speciated
airborne measurements of fine aerosol, revealing large biases in the
ammonium and nitrate simulations. To address this, we incorporate
process-level changes to the model and use satellite observations
from the Cross-track Infrared Sounder (CrIS) and the TROPOspheric
Monitoring Instrument (TROPOMI) to constrain ammonia and nitrogen
oxide emissions. The resulting simulation demonstrates significantly
lower bias (NMBModified: 0.19; NMBBase: 0.61)
when validated against the airborne aerosol measurements, particularly
for the nitrate (NMBModified: 0.08; NMBBase:
1.64) and ammonium simulation (NMBModified: 0.49; NMBBase: 0.90). We use this validated simulation to estimate a
population-weighted annual PM2.5 exposure of 61.4 μg
m–3, with the RCO (residential, commercial, and
other) and energy sectors contributing 21% and 19%, respectively,
resulting in an estimated 961,000 annual PM2.5-attributable
deaths. Regional exposure and sectoral source contributions differ
meaningfully in the improved simulation (compared to the baseline
simulation). Our work highlights the critical role of speciated observational
constraints in developing accurate model-based PM2.5 aerosol
source attribution for health assessments and air quality management
in India