Search

Volatile organic compounds (VOCs) are an important class of environmental pollutants, and there is much interest in China to eliminate such pollutants. Noble metal catalysts have long been a family of catalysts with high efficiency and good low-temperature catalytic activity. As a representative of the noble metals, Pt has been widely used. This paper reviews the research trend of Pt-based catalysts for the catalytic oxidation of VOCs, and it compares several important components of Pt-based catalysts. The size of Pt particles, supported carriers, and reaction mechanism are reviewed. Toluene in VOCs is the main research subject. The activity, stability, water resistance, and selectivity of a series of Pt-based catalysts are summarized. [ABSTRACT FROM AUTHOR]

The conventional fire assay method to determine high grade gold has a long chemical procedure with many factors influencing the analysis result. Moreover, the ash blowing process for the Pb button volatilizes a large amount of Pb, causing serious pollution to the environment. In this paper, a method is described whereby the 20.0-100.0 g sample was split into small amounts and calcinated. The products of calcination were dissolved by 50% aqua regia and the residues were filtered. All the clean filtrates were loaded into a volumetric flask. An appropriate volume of solution was selected to extract Au with foam enrichment. After ashing the Au bearing foams, the Au was dissolved again by concentrated aqua regia. Then, the Au was measured by Flame Atomic Absorption Spectrometry (FAAS). The detection limit was 0.101 μg/g. Through verifications for a few national first grade standard materials and the analysis samples, the accuracy and precision met the relevant requirements. The sampling weight was from 20.0 g to 100.0 g which effectively improved the sample representativeness and extended the analysis content range for Au by FAAS. This method is also suitable for samples with Au contents from 50.0 μg/g to 550.0 μg/g.

The impact of diet on the metabolic syndrome (MetS) and CVD has been investigated widely, but few studies have investigated the association between dietary patterns (DP) and the predicted CVD, derived from reduced rank regression (RRR). The objectives of this study were to derive DP using RRR and principal component analysis (PCA) and investigate their associations with the MetS and estimated 10-year atherosclerotic CVD (ASCVD). We used the baseline dataset from the Xinjiang multi-ethnic cohort study in China, collected from June 2018 to May 2019. A total of 14 982 subjects aged 35–74 years from Urumqi, Huo Cheng and Mo Yu were included in the analysis. The 10-year ASCVD risk was estimated using the Chinese ASCVD risk equations. The associations of DP with the MetS and 10-year ASCVD were determined using multivariable logistic regression models. In Urumqi and Mo Yu, the increased RRR DP score was associated with a higher OR of having the MetS and with a higher OR of elevated 10-year ASCVD risk. However, only the first DP determined by PCA in Urumqi was inversely associated with the MetS and elevated 10-year ASCVD risk. The prevalence of the MetS and elevated ASCVD risk in urban population is higher than that in rural areas. Our results may help nutritionists develop more targeted dietary strategies to prevent the MetS and ASCVD in different regions in China. [ABSTRACT FROM AUTHOR]

Background: Older adults are at high risk of femoral neck fractures (FNFs). Elderly patients face and adapt to significant psychological burdens, resulting in different degrees of psychological stress response. Total hip replacement is the preferred treatment for FNF in elderly patients; however, some patients have poor postoperative prognoses, and the underlying mechanism is unknown. We speculated that the postoperative prognosis of elderly patients with FNF may be related to preoperative psychological stress., Aim: To explore the relationship between preoperative psychological stress and the short-term prognosis of elderly patients with FNF., Methods: In this retrospective analysis, the baseline data, preoperative 90-item Symptom Checklist score, and Harris score within 6 months of surgery of 120 elderly patients with FNF who underwent total hip arthroplasty were collected. We analyzed the indicators of poor short-term postoperative prognosis and the ability of the indicators to predict poor prognosis and compared the correlation between the indicators and the Harris score., Results: Anxiety, depression, garden classification of FNF, cause of fracture, FNF reduction quality, and length of hospital stay were independent influencing factors for poor short-term postoperative prognoses in elderly patients with FNF ( P < 0.05). The areas under the curve for anxiety, depression, and length of hospital stay were 0.742, 0.854, and 0.749, respectively. The sensitivities of anxiety, depression, garden classification of FNF, and prediction of the cause of fracture were 0.857, 0.786, 0.821, and 0.821, respectively. The specificities of depression, FNF quality reduction, and length of hospital stay were the highest at 0.880, 0.783, and 0.761, respectively. Anxiety, depression, and somatization scores correlated moderately with Harris scores ( r = -0.523, -0.625, and -0.554; all P < 0.001)., Conclusion: Preoperative anxiety, depression, and somatization are correlated with poor short-term prognosis in elderly patients with FNF and warrant consideration., Competing Interests: Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

The incubation period for Hepatitis B virus (HBV) within the human is epidemiologically significant because it is typically of long duration (1.5∼6 months) and the disease transmission possibility may be increased due to more contact from the patients in this period. In this paper, we investigate an SEICRV epidemic model with time delay to research the transmission dynamics of Hepatitis B disease. The basic reproductive number ${\mathcal R}&#95;0$ is derived and can determine the dynamics of the model. The disease-free equilibrium is globally asymptotically stable if ${\mathcal R}&#95;0<1 and="" unstable="" if="" mathcal="" r="" &#95;0="">1$. As ${\mathcal R}&#95;0>1$, the model admits a unique endemic equilibrium which is locally asymptotically stable. The endemic equilibrium is globally asymptotically stable when the vertical transmission is ignored. Numerically, we study the Hepatitis B transmission case in Xinjiang, China. Using the Hepatitis B data from Xinjiang, the basic reproductive number is estimated as 1.47 (95% CI: 1.34-1.50). By the end of 2028, the cumulative number of Hepatitis B cases in Xinjiang will be estimated about 700,000 if there is no more effective preventive measures. The sensitivity analysis of ${\mathcal R}&#95;0$ in terms of parameters indicates prevention and treatment for chronic patients are key measures in controlling the spread of Hepatitis B in Xinjiang.