Increasing nitrogen (N) deposition or fertilization has been found to significantly affect carbon (C) cycling. However, a comprehensive understanding of how different C chemical components of plant, ...litter, and soil would respond to external N addition is still lacking. We compiled data of 1,160 observations from 52 individual studies and conducted a metaâanalysis of N addition effects on 18 variables related to C chemical compositions in terrestrial ecosystems. Results showed that plant lignin (+7.13%), plant protein (+25.94%), and soil lignin (+7.30%) were significantly increased by N addition, and plant hemicellulose (â4.39%) was significantly decreased, whereas plant fiber, plant cellulose, plant nonâstructural carbohydrate (NSC), litter lignin, and litter cellulose were not significantly changed. The effects of N addition on C chemical composition varied among different ecosystems/plant types and different forms of N addition. Increasing treatment duration did not significantly change the effects of N addition on the chemical composition of plant, litter, and soil C. With increasing N addition rate, the effect of N addition on plant lignin, plant fiber, plant cellulose, and plant protein increased, while the effect of N addition on plant hemicellulose, plant NSC, and litter cellulose became more negative. Our metaâanalysis provided a systematic evaluation of the responses of different C chemical components to N addition in the plantâlitterâsoil continuum. Results suggest that the change of plant and soil C chemical composition under N addition may be beneficial for ecosystem C sequestration and could affect ecosystem structure and function in the future.
Compared to the severe winter haze episodes in the North China Plain (NCP),
haze pollution during summertime has drawn little public attention. In this
study, we present the highly time-resolved ...chemical composition of submicron
particles (PM1) measured in Beijing and Xinxiang in the NCP region
during summertime to evaluate the driving factors of aerosol pollution.
During the campaign periods (30 June to 27 July 2015, for Beijing and 8 to
25 June 2017, for Xinxiang), the average PM1 concentrations were 35.0
and 64.2 µg m−3 in Beijing and Xinxiang. Pollution episodes
characterized with largely enhanced nitrate concentrations were observed at
both sites. In contrast to the slightly decreased mass fractions of sulfate,
semivolatile oxygenated organic aerosol (SV-OOA), and low-volatility
oxygenated organic aerosol (LV-OOA) in PM1, nitrate displayed a
significantly enhanced contribution with the aggravation of aerosol
pollution, highlighting the importance of nitrate formation as the driving
force of haze evolution in summer. Rapid nitrate production mainly occurred
after midnight, with a higher formation rate than that of sulfate, SV-OOA, or
LV-OOA. Based on observation measurements and thermodynamic modeling, high
ammonia emissions in the NCP region favored the high nitrate production in
summer. Nighttime nitrate formation through heterogeneous hydrolysis of
dinitrogen pentoxide (N2O5) enhanced with the development of haze
pollution. In addition, air masses from surrounding polluted areas during
haze episodes led to more nitrate production. Finally, atmospheric
particulate nitrate data acquired by mass spectrometric techniques from
various field campaigns in Asia, Europe, and North America uncovered a higher
concentration and higher fraction of nitrate present in China. Although
measurements in Beijing during different years demonstrate a decline in the
nitrate concentration in recent years, the nitrate contribution in PM1
still remains high. To effectively alleviate particulate matter pollution in
summer, our results suggest an urgent need to initiate ammonia emission
control measures and further reduce nitrogen oxide emissions over the NCP
region.
Synthesising evidence on the long-term vaccine effectiveness of COVID-19 vaccines (BNT162b2 Pfizer-BioNTech, mRNA-1273 Moderna, ChAdOx1 nCoV-19 AZD1222; Oxford-AstraZeneca, and Ad26.COV2.S Janssen) ...against infections, hospitalisations, and mortality is crucial to making evidence-based pandemic policy decisions.
In this rapid living systematic evidence synthesis and meta-analysis, we searched EMBASE and the US National Institutes of Health's iSearch COVID-19 Portfolio, supplemented by manual searches of COVID-19-specific sources, until Dec 1, 2022, for studies that reported vaccine effectiveness immediately and at least 112 days after a primary vaccine series or at least 84 days after a booster dose. Single reviewers assessed titles, abstracts, and full-text articles, and extracted data, with a second reviewer verifying included studies. The primary outcomes were vaccine effectiveness against SARS-CoV-2 infections, hospitalisations, and mortality, which were assessed using three-level meta-analytic models. This study is registered with the National Collaborating Centre for Methods and Tools, review 473.
We screened 16 696 records at the title and abstract level, appraised 832 (5·0%) full texts, and initially included 73 (0·4%) studies. Of these, we excluded five (7%) studies because of critical risk of bias, leaving 68 (93%) studies that were extracted for analysis. For infections caused by any SARS-CoV-2 strain, vaccine effectiveness for the primary series reduced from 83% (95% CI 80-86) at baseline (14-42 days) to 62% (53-69) by 112-139 days. Vaccine effectiveness at baseline was 92% (88-94) for hospitalisations and 91% (85-95) for mortality, and reduced to 79% (65-87) at 224-251 days for hospitalisations and 86% (73-93) at 168-195 days for mortality. Estimated vaccine effectiveness was lower for the omicron variant for infections, hospitalisations, and mortality at baseline compared with that of other variants, but subsequent reductions occurred at a similar rate across variants. For booster doses, which covered mostly omicron studies, vaccine effectiveness at baseline was 70% (56-80) against infections and 89% (82-93) against hospitalisations, and reduced to 43% (14-62) against infections and 71% (51-83) against hospitalisations at 112 days or later. Not enough studies were available to report on booster vaccine effectiveness against mortality.
Our analyses indicate that vaccine effectiveness generally decreases over time against SARS-CoV-2 infections, hospitalisations, and mortality. The baseline vaccine effectiveness levels for the omicron variant were notably lower than for other variants. Therefore, other preventive measures (eg, face-mask wearing and physical distancing) might be necessary to manage the pandemic in the long term.
Canadian Institutes of Health Research and the Public Health Agency of Canada.
This study aimed to determine the cause of the outbreak of nosocomial adenoviral conjunctivitis in the Neonatal Intensive Care Unit (NICU) and the impact of infection control measures. The objectives ...of the present study included investigating the association between hospital-borne infection and adenoviral conjunctivitis, analyzing the possible risk factors, and setting bundled infection control measures, which were adjusted according to the control effect. This study also aimed to observe the effects of different intervention measures on controlling adenoviral conjunctivitis. During the first and second intervention periods, 635 and 597 patients in the NICU were enrolled, respectively. Ophthalmoscopy was performed in 188 ( first intervention) and 184 (second intervention) patients (P > 0.05) 417 and 457 times, respectively (P < 0.001). During the first intervention and second interventions, 13 patients and no patient had adenoviral conjunctivitis, respectively (P < 0.001). All adenoviral conjunctivitis cases were reported 6–27 days (mean, 12 days) after ophthalmoscopy. Hydrogen peroxide disinfection bundled measures can effectively restrict the prevalence of adenoviral conjunctivitis associated with ophthalmoscopy in premature infants.
Five OXA-232 carbapenemase-producing
isolates, belonging to the pandemic clone sequence type 15 (ST15), were isolated from neonates and coproduced
and
genes. All isolates were resistant to ertapenem ...(MICs of >32 μg/ml) and meropenem (MICs of 4 to 8 μg/ml) and susceptible or intermediate to imipenem (MICs of 1 to 2 μg/ml). The
gene was located on a ColE-type transformable plasmid of 6,141 bp. To the best of our knowledge, this is the first report of OXA-232 carbapenemase among clinical isolates in China.
To control the spread of COVID-19, China implemented a series of lockdowns, limiting various offline interactions. This provided an opportunity to study the response of air quality to emissions ...control. By comparing the characteristics of pollution in the summers of 2019 and 2020, we found a significant decrease in gaseous pollutants in 2020. However, particle pollution in the summer of 2020 was more severe; PM2.5 levels increased from 35.8 to 44.7 μg m−3, and PM10 increased from 51.4 to 69.0 μg m−3 from 2019 to 2020. The higher PM10 was caused by two sandstorm events on May 11 and June 3, 2020, while the higher PM2.5 was the result of enhanced secondary formation processes indicated by the higher sulfate oxidation rate (SOR) and nitrate oxidation rate (NOR) in 2020. Higher SOR and NOR were attributed mainly to higher relative humidity and stronger oxidizing capacity. Analysis of PMx distribution showed that severe haze occurred when particles within Bin2 (size ranging 1–2.5 μm) dominated. SO42−(1/2.5) and SO42−(2.5/10) remained stable under different periods at 0.5 and 0.8, respectively, indicating that SO42− existed mainly in smaller particles. Decreases in NO3−(1/2.5) and increases in NO3−(2.5/10) from clean to polluted conditions, similar to the variations in PMx distribution, suggest that NO3− played a role in the worsening of pollution. O3 concentrations were higher in 2020 (108.6 μg m−3) than in 2019 (96.8 μg m−3). Marked decreases in fresh NO alleviated the titration of O3. Furthermore, the oxidation reaction of NO2 that produces NO3− was dominant over the photochemical reaction of NO2 that produces O3, making NO2 less important for O3 pollution. In comparison, a lower VOC/NOx ratio (less than 10) meant that Beijing is a VOC-limited area; this indicates that in order to alleviate O3 pollution in Beijing, emissions of VOCs should be controlled.
Display omitted
•Precursors were significantly reduced by COVID-19 lockdown in summer 2020.•Stronger secondary processes caused higher particle pollution in summer 2020.•Beijing is VOC-limited in O3 pollution.
Haze pollution in summer 2020 was more severe because of the stronger secondary processes despite the rapid decrease of precursors caused by the COVID-19 lockdown.
The Ten Eleven Translocation 1 (TET1) protein is a DNA demethylase that regulates gene expression through altering statue of DNA methylation. However, recent studies have demonstrated that TET1 could ...modulate transcriptional expression independent of its DNA demethylation activity; yet, the detailed mechanisms underlying TET1's role in such transcriptional regulation remain not well understood. Here, we uncovered that Tet1 formed a chromatin complex with histone acetyltransferase Mof and scaffold protein Sin3a in mouse embryonic stem cells by integrative genomic analysis using publicly available ChIP-seq data sets and a series of in vitro biochemical studies in human cell lines. Mechanistically, the TET1 facilitated chromatin affinity and enzymatic activity of hMOF against acetylation of histone H4 at lysine 16 via preventing auto-acetylation of hMOF, to regulate expression of the downstream genes, including DNA repair genes. We found that Tet1 knockout MEF cells exhibited an accumulation of DNA damage and genomic instability and Tet1 deficient mice were more sensitive to x-ray exposure. Taken together, our findings reveal that TET1 forms a complex with hMOF to modulate its function and the level of H4K16Ac ultimately affect gene expression and DNA repair.
Free conductive particles in a gas‐insulated metal‐enclosed system produce partial discharges during movement, resulting in insulator flashover and insulation failures. This study focuses on the ...partial discharge property of free conductive particles under DC and AC voltages. The relationship between the micro‐discharge property and the intrinsic properties of the particles was obtained based on experimental tests. The results show that under DC conditions, the local discharge property varies linearly with particle size and density. The discharge probability of particles in SF6 is significantly reduced compared with that in air, while the discharge magnitude rapidly increases if the lift voltage exceeds a certain value. Under AC conditions, the partial discharge generated by the particle becomes less random, and the amplitude and phase angle of the discharge are not significantly related. As the size of the electrode decreases, the partial discharge current generated by the particles on the surface of the electrode with an uneven electric field increases significantly. This research provides a basis for the optimization of withstand voltage test method and its applications.
Root traits and arbuscular mycorrhizal (AM) fungi are important in determining the access of plants to soil resources. However, whether plants with different root systems (i.e., taproot vs. ...fibrous-root) exhibit different root trait plasticity and mycorrhizal responsiveness under drought remains largely unexplored. Tap-rooted
and fibrous-rooted
were grown in monocultures in sterilized and live soils, followed by a drought treatment. Biomass, root traits, root colonization by AM fungi, and nutrient availability were evaluated. Drought decreased biomass and root diameter but increased the root:shoot ratio (RSR), specific root length (SRL), soil NO
-N, and available P for the two species. Under control and drought conditions, soil sterilization significantly increased the RSR, SRL, and soil NO
-N for
, but this only occurs under drought condition for
. Soil sterilization significantly reduced AM fungal root colonization of both species, but drought significantly increased it in live soil. In water-abundant conditions, tap-rooted
may depend more on AM fungi than fibrous-rooted
; however, under drought conditions, AM fungi are of equal importance in favoring both plant species to forage soil resources. These findings provide new insights for understanding the resource utilization strategies under climate change.
Abstract
Emissions in many sources are estimated in municipal district totals and spatially disaggregated onto grid cells using empirically selected spatial proxies such as population density, which ...might introduce biases, especially in fine spatial scale. Efforts have been made to improve the spatial representation of emission inventory, by incorporating comprehensive point source database (e.g. power plants, industrial facilities) in emission estimates. Satellite-based observations from the TROPOspheric Monitoring Instrument (TROPOMI) with unprecedented pixel sizes (3.5 × 7 km
2
) and signal-to-noise ratios offer the opportunity to evaluate the spatial accuracy of such highly resolved emissions from space. Here, we compare the city-level NO
x
emissions from a proxy-based emission inventory named the Multi-resolution Emission Inventory for China (MEIC) with a highly resolved emission inventory named the Multi-resolution Emission Inventory for China - High Resolution (MEIC-HR) that has nearly 100 000 industrial facilities, and evaluate them through NO
x
emissions derived from the TROPOMI NO
2
tropospheric vertical column densities (TVCDs). We find that the discrepancies in city-level NO
x
emissions between MEIC and MEIC-HR are influenced by the proportions of emissions from point sources and NO
x
emissions per industrial gross domestic product (IGDP). The use of IGDP as a spatial proxy to disaggregate industrial emissions tends to overestimate NO
x
emissions in cities with lower industrial emission intensities or less industrial facilities in the MEIC. The NO
x
emissions of 70 cities are derived from one year TROPOMI NO
2
TVCDs using the exponentially modified Gaussian function. Compared to the satellite-derived emissions, the cities with higher industrial point source emission proportions in MEIC-HR agree better with space-constrained results, indicating that integrating more point sources in the inventory would improve the spatial accuracy of emissions on city scale. In the future, we should devote more efforts to incorporating accurate locations of emitting facilities to reduce uncertainties in fine-scale emission estimates and guide future policies.
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