30 research outputs found

    Persistent sulfate formation from London Fog to Chinese haze

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    Sulfate aerosols exert profound impacts on human and ecosystem health, weather, and climate, but their formation mechanism remains uncertain. Atmospheric models consistently underpredict sulfate levels under diverse environmental conditions. From atmospheric measurements in two Chinese megacities and complementary laboratory experiments, we show that the aqueous oxidation of SO2 by NO2 is key to efficient sulfate formation but is only feasible under two atmospheric conditions: on fine aerosols with high relative humidity and NH3 neutralization or under cloud conditions. Under polluted environments, this SO2 oxidation process leads to large sulfate production rates and promotes formation of nitrate and organic matter on aqueous particles, exacerbating severe haze development. Effective haze mitigation is achievable by intervening in the sulfate formation process with enforced NH3 and NO2 control measures. In addition to explaining the polluted episodes currently occurring in China and during the 1952 London Fog, this sulfate production mechanism is widespread, and our results suggest a way to tackle this growing problem in China and much of the developing world

    Two-Neuron Based Memristive Hopfield Neural Network with Synaptic Crosstalk

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    Synaptic crosstalk is an important biological phenomenon that widely exists in neural networks. The crosstalk can influence the ability of neurons to control the synaptic weights, thereby causing rich dynamics of neural networks. Based on the crosstalk between synapses, this paper presents a novel two-neuron based memristive Hopfield neural network with a hyperbolic memristor emulating synaptic crosstalk. The dynamics of the neural networks with varying memristive parameters and crosstalk weights are analyzed via the phase portraits, time-domain waveforms, bifurcation diagrams, and basin of attraction. Complex phenomena, especially coexisting dynamics, chaos and transient chaos emerge in the neural network. Finally, the circuit simulation results verify the effectiveness of theoretical analyses and mathematical simulation and further illustrate the feasibility of the two-neuron based memristive Hopfield neural network hardware

    Preparation and Characterization of Erythrocyte Membrane-Camouflaged Berberine Hydrochloride-Loaded Gelatin Nanoparticles

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    The discovery of a new pharmacological application of berberine hydrochloride (BH) made it more clinically valuable. However, the further development of BH was hampered by its short half-life and side effects after intravenous injection. To overcome these problems, a novel BH delivery system was developed using natural red blood cell membrane-camouflaged BH-loaded gelatin nanoparticles (RBGPs) to reduce the toxicity associated with injections and achieve sustained release. The size of the RBGPs was 260.3 ± 4.1 nm, with an obvious core–shell structure, and the membrane proteins of the RBGPs were mostly retained. The RBGP system showed significant immune-evading capabilities and little cytotoxicity to human embryonic kidney (HEK) 293T cells and LO2 cells. Finally, RBGPs improved the sustained releasing effect of BH significantly. When the cumulative release time reached 120 h, the cumulative release rate of RBGPs was 78.42%. In brief, RBGPs hold the potential to achieve long circulation and sustained-release of BH, avoid side effects caused by high plasma concentration in common injection formulations, and broaden the clinical applications of BH

    Emission Characteristics of Particulate Matter from Boiling Food

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    Cooking food in water or soup, such as hot pot, is a widely used cooking method in China. This type of cooking requires no oil and cooks at a lower temperature, but that does not mean it produces fewer pollutants or is less harmful. There are few research studies on the emission characteristics and mechanisms of particulate matter emissions when eating hot pot (the boiling process), which leads to the unreasonable design of ventilation systems for this kind of catering. In this paper, the effects of boiling different ingredients (including noodles, potatoes, fish, tofu, meatballs, and pork) on particle number concentration emissions were studied. The particle number concentration and particle size distribution of PM with diameters of 0.3 μm and less, 0.3–0.5 μm and 0.5–1.0 μm (PM0.3, PM0.3–0.5 and PM0.5–1.0, respectively) were measured in an experimental chamber. The food type and shape showed very little change in the PM emission characteristics of boiling. When the boiling state was reached, the number concentration, particle size distribution, and arithmetic mean diameter of particles all fluctuated within 60 s. The emission characteristics of particles produced by boiling water and heating oil were compared. Heating oil produced more small particles, and boiling water released more large particles. Transient and steady methods were used to calculate the emission rate of particles, and the steady-state calculation has a high estimation of the emission rate

    Genome-Wide Characterization, Evolution, and Expression Profiling of <i>VQ</i> Gene Family in Response to Phytohormone Treatments and Abiotic Stress in <i>Eucalyptus grandis</i>

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    VQ genes play important roles in plant development, growth, and stress responses. However, little information regarding the functions of VQ genes is available for Eucalyptus grandis. In our study, genome-wide characterization and identification of VQ genes were performed in E. grandis. Results showed that 27 VQ genes, which divided into seven sub-families (I&#8211;VII), were found, and all but two VQ genes showed no intron by gene structure and conserved motif analysis. To further identify the function of EgrVQ proteins, gene expression analyses were also developed under hormone treatments (brassinosteroids, methyl jasmonate, salicylic acid, and abscisic acid) and abiotic conditions (salt stress, cold 4 &#176;C, and heat 42 &#176;C). The results of a quantitative real-time PCR analysis indicated that the EgrVQs were variously expressed under different hormone treatments and abiotic stressors. Our study provides a comprehensive overview of VQ genes in E. grandis, which will be beneficial in the molecular breeding of E. grandis to promote its resistance to abiotic stressors; the results also provide a basis from which to conduct further investigation into the functions of VQ genes in E. grandis

    Maize Straw Return and Nitrogen Rate Effects on Potato (Solanum tuberosum L.) Performance and Soil Physicochemical Characteristics in Northwest China

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    The average yield of fresh potato tubers per hectare is relatively low in China, partly due to poor nutrient management. Chronic inorganic N enrichment leads to soil acidification, which deteriorates soil fertility. Straw residues are removed from the field or burnt during land preparation, resulting in nutrient depletion and air pollution. However, these residues can be returned to the soil to improve its fertility. Therefore, a two–year experiment was conducted in an existing field with five years of different inorganic nitrogen (N) rate to determine the effects of straw return and N rate on potato growth, tuber yield, and quality, profit margin, and soil physicochemical properties. The experiment consisted of four N rates: 0 (control, CK), 75 (low N rate, LN), 150 (medium N rate, MN), and 300 (high N rate, HN) kg N ha−1 with and without straw (9 t ha−1) return. The results showed that straw with N enrichment improved soil fertility, which increased tuber yield and quality. Compared to the control, MN + straw treatment stimulated economic tuber yield (34.73% and 38.34%), profit margin (55.51% and 63.03%), and protein content (20.04% and 25.46%) in 2018 and 2019, respectively. Nitrogen enrichment after straw return is a sustainable practice for stimulating potato tuber yield, profit margin, and improving soil fertility to promote sustainable agriculture development

    Trends in gynaecologic cancer mortality and the impact of the COVID-19 pandemic in the United States

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    Abstract Objectives Our aim was to assess the trend in gynaecologic cancer (GC) mortality in the period from 2010 to 2022 in the United States, with focus on the impact of the pandemic on increased deaths. Methods GC mortality data were extracted from the Center for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research (CDC WONDER) platform. We analysed mortality trends and evaluated observed vs. predicted mortality for the period from 2020 to 2022 with joinpoint regression and prediction modelling analyses. Results A total of 334,382 deaths among adults aged 25 years and older with gynaecologic cancer were documented from 2010 to 2022. The overall age-standardised mortality rate (ASMR, per 100,000 persons) for ovarian cancer-related death decreased gradually from 7.189 in 2010 to 5.517 in 2019, yielding an APC (annual percentage change) of -2.8%. However, the decrease in ovarian cancer-related mortality slowed down by more than 4-fold during the pandemic. Cervical cancer -related mortality decreased slightly prior to the pandemic and increased during the pandemic with an APC of 0.6%, resulting in excess mortality of 4.92%, 9.73% and 2.03% in 2020, 2021 and 2022, respectively. For uterine corpus cancer, the ASMR increased from 1.905 in 2010 to 2.787 in 2019, and increased sharply to 3.079 in 2021 and 3.211 in 2022. The ASMR rose steadily between 2013 and 2022, yielding an APC of 6.9%. Conclusions Overall, we found that GC-related mortality increased during the COVID-19 pandemic, and this increase was not specific to age, race, or ethnicity

    Uniform PdH0.33 nanodendrites with a high oxygen reduction activity tuned by lattice H

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    We report the synthesis of β-palladium hydride nanodendrites (PdH0.33 NDs). The uniform PdH0.33 NDs are 36.3 ± 5.0 nm in diameter and selectively expose (111) planes decorated with (221) and (331) high-indexed steps. The PdH0.33 NDs show a high mass activity of 0.719 A/mgPd at 0.9 V (vs. reversible hydrogen electrode-RHE) toward alkaline oxygen reduction reaction (ORR), which is 3.7 and 6.3 times that of commercial Pt/C and house-made Pd/C, respectively. This study exemplifies the possibility of using special morphology and lattice H to modify the strain and electronic effect of metal for the optimization of functionalities. Keywords: Palladium hydride, Nanodendrites, Oxygen reduction reaction, Oxygen adsorption energ
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