In the past two decades, on account of the energy and environmental crisis brought by the decline in fossil resources, price volatility, and climate change, the high-value utilization of biomass ...feedstocks has gradually attracted widespread attention. Catalytic conversion of biomass usually involves tandem activation and cleavage of C–C and C–O bonds. Some steps occur in the aqueous phase and demand catalysts of high water resistance. Water-resistant ceria with redox and acid–base synergistic catalytic sites has attracted great interests particularly for biomass upgradation. The reversible Ce3+/Ce4+ redox pairs and the existence of oxygen vacancies improve its redox ability and thus catalytic activity. Besides, the acid–base properties enable its use in acid–base catalytic reactions. The strength or concentration of acid–base sites is tailorable. The water-tolerance character is unique and thus can be employed in the conversion of dilute aqueous biomass solutions. In this Perspective, we summarize the latest research progress in the high-value utilization of biomass feedstocks, including biomass raw materials, platform molecules originated from biomass as well as its derivatives and downstream chemicals over pure CeO2, doped CeO2, and CeO2-supported metal catalysts.
The recent novel coronavirus disease (COVID-19) outbreak, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is seeing a rapid increase in infected patients worldwide. The host ...immune response to SARS-CoV-2 appears to play a critical role in disease pathogenesis and clinical manifestations. SARS-CoV-2 not only activates antiviral immune responses, but can also cause uncontrolled inflammatory responses characterized by marked pro-inflammatory cytokine release in patients with severe COVID-19, leading to lymphopenia, lymphocyte dysfunction, and granulocyte and monocyte abnormalities. These SARS-CoV-2-induced immune abnormalities may lead to infections by microorganisms, septic shock, and severe multiple organ dysfunction. Therefore, mechanisms underlying immune abnormalities in patients with COVID-19 must be elucidated to guide clinical management of the disease. Moreover, rational management of the immune responses to SARS-CoV-2, which includes enhancing anti-viral immunity while inhibiting systemic inflammation, may be key to successful treatment. In this review, we discuss the immunopathology of COVID-19, its potential mechanisms, and clinical implications to aid the development of new therapeutic strategies against COVID-19.
The interface of metal-oxide plays pivotal roles in catalytic reactions, but its catalytic function is still not clear. In this study, we report the high activity of nanostructured Ru/ceria ...(Ru-clusters/ceria) in the ethylene methoxycarbonylation (EMC) reaction in the absence of acid promoter. The catalyst offers 92% yield of MP with TOF of 8666 h–1, which is about 2.5 times of homogeneous Pd catalyst (∼3500 h–1). The interfacial Lewis acid–base pair Ru-O-Ce-Vö, which consists of acidic Ce-Vö (oxygen vacancy) site and basic interfacial oxygen of Ru-O-Ce linkage, acts as active site for the dissociation of methanol and the subsequent transfer of hydrogen to the activated ethylene, which is the key step in acid-promoter-free EMC reaction. The combination of 1H MAS NMR, pyridine-IR and DFT calculations reveals the hydrogen species derived from methanol contains Brönsted acidity. The EMC reaction mechanism under acid-promoter-free condition over Ru-clusters/ceria catalyst is discussed.
To obtain realistic forecasts of the impacts of climate change on species habitat suitability, novel approaches based on species distribution models (SDMs) are being developed and scrutinized. We ...argue here that, when dealing with data from long-term monitoring programmes, incorporating a temporal weight on the occurrence points may result in a more realistic prediction of a species' potential distribution. Using larval fish presence records collected from 1999 to 2013 in the Yangtze Estuary, China, we compared the performance of ensembles of standard SDMs versus SDMs constructed with weighted time-series presence records in predicting the present and future distributions of the larval stages of two dominant fish. The results of the ensemble SDMs showed that weighted presence records can significantly improve SDM performance, as measured through standard validation metrics. The SDM projections suggest that suitable habitat for both species will decrease under future climate scenarios, with one species (Stolephorus commersonnii) predicted to be more susceptible to climate change than the other (Engraulis japonicus). In addition to range contraction, model projections suggest that the future habitats of both species will shift northward—an implication of climate change that should be considered in future management and conservation strategies for the Yangtze Estuary.
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•Ensemble SDMs were developed for two dominant fish larvae in the Yangtze Estuary.•Weighting time-series presence records can greatly improve SDM predictive abilities.•Suitable larval habitat of both species will likely decrease and shift northward.•Time-series presence data should be better incorporated into future SDM studies.•Climate adaptation strategies should be considered to protect larvae in this region.
At present, with the applying of distributed energy resource (DER) in the demand side, the difficulty of demand-side management (DSM) is increasing. Improving the consumption rate of DER is currently ...one of the important research contents of the home energy management system (HEMS). How to better coordinate household appliances to participate in the HEMS, so as to improve the situation is the focus of this paper. Due to the development of artificial intelligence and communication technology, we establish a household appliance optimization scheduling system. According to the household electricity-using habits, most household appliances are divided into three categories. Based on this, we propose a HEMS model, which aims to minimize the peak load and electricity cost of a smart home, and achieve single-objective and multi-objective optimization. In order to better implement the research of DER, the solar radiation data of one day in summer in Shanghai is used to compare with different capacities of photovoltaic energy storage system (PESS). Because the variables in the model are mostly binary or decimal integers, it is essentially a mixed integer programming (MIP). Therefore, a simulator has been implemented in the MATLAB software environment to facilitate the solution of proposed HEMS. The results show that the configuration of PESS is beneficial to the optimal scheduling of household appliances. In the single objective optimization, the peak load and electricity cost of scheme 4 is decreased by 61.51% and 71.39% compared with scheme 1, respectively. Besides, Pareto front is the most ideal in multi-objective optimization under scheme 4, and Pareto solutions distribution are more uniform, which can provide more scheduling choices for residential users. In addition, by comparing the different photovoltaic (PV) subsidy policies in 2013 and 2018, it is reasonable for China to gradually realize PV subsidy-free.
Aqueous activities on Mars have gradually declined since the Noachian (>3.7 Ga). Although water can be stored in the subsurface during the latest epochs, geomorphological evidence is still limited. ...In this study, we used in situ imaging and spectral data acquired by China's Zhurong rover, as well as high‐resolution remote‐sensing data, to investigate the transverse aeolian ridges (TARs) in the Zhurong landing region of Utopia Planitia. A two‐stage evolutionary scenario of the TARs is proposed and polygonal features with hydrated minerals are identified for the first time on the surface of Martian TARs. We discussed the possible formation mechanisms of the polygonal features, and proposed that they could be related to recent aqueous activity and atmosphere‐surface water exchange on Mars, which sheds light on the hydrological cycle of Mars in current cold and dry climate.
Plain Language Summary
The history of water on the surface of Mars has been studied for a long time. Since about 3.7 billion years ago, the role of water has gradually declined. Although the existence of subsurface ice on present‐day Mars has been confirmed, evidence for surface water is still limited. Transverse aeolian ridges (TARs), a kind of ripple‐like aeolian landform, are widely distributed on Mars and usually thought to be active within the last ∼3 million years. They are also identified in southern Utopia Planitia, the landing region of China's Mars exploration rover Zhurong. We analyzed the morphology and evolution of the TARs in the Zhurong landing region, and found some polygonal features with hydrated minerals such as gypsum on the surface of the latest‐formed TARs. We discussed the possible origins of these polygons, and proposed that they represent very recent aqueous activity on the Martian surface, which will help us better understand the hydrological cycle on current Mars.
Key Points
Morphology and evolution of the transverse aeolian ridges (TARs) in the Zhurong landing region are studied
Polygonal features with hydrated minerals are identified on some of the TARs investigated by the Zhurong rover
The polygons could be related to very recent aqueous activity and atmosphere‐surface water exchange on Mars
Rooftop photovoltaics (RPVs) are crucial in achieving energy transition and climate goals, especially in cities with high building density and substantial energy consumption. Estimating RPV carbon ...mitigation potential at the city level of an entire large country is challenging given difficulties in assessing rooftop area. Here, using multi-source heterogeneous geospatial data and machine learning regression, we identify a total of 65,962 km
rooftop area in 2020 for 354 Chinese cities, which represents 4 billion tons of carbon mitigation under ideal assumptions. Considering urban land expansion and power mix transformation, the potential remains at 3-4 billion tons in 2030, when China plans to reach its carbon peak. However, most cities have exploited less than 1% of their potential. We provide analysis of geographical endowment to better support future practice. Our study provides critical insights for targeted RPV development in China and can serve as a foundation for similar work in other countries.
Obesity is characterized by excessive body fat accumulation and is a high-risk factor for metabolic comorbidities, including type 2 diabetes, nonalcoholic fatty liver disease, and cardiovascular ...disease. In lean individuals, adipose tissue (AT) is not only an important regulatory organ for energy storage and metabolism, but also an indispensable immune and endocrine organ. The sustained energy imbalance induces adipocyte hypotrophy and hyperplasia as well as AT remodeling, accompanied by chronic low-grade inflammation and adipocytes dysfunction in AT, ultimately leading to systemic insulin resistance and ectopic lipid deposition. Luteolin is a natural flavonoid widely distributed in fruits and vegetables and possesses multifold biological activities, such as antioxidant, anticancer, and anti-inflammatory activities. Diet supplementation of this flavonoid has been reported to inhibit AT lipogenesis and inflammation as well as the ectopic lipid deposition, increase AT thermogenesis and systemic energy expenditure, and finally improve obesity and associated metabolic diseases. The purpose of this review is to reveal the nutritional activities of luteolin in obesity and its complications with emphasis on its action on AT energy metabolism, immunoregulation, and endocrine intervention.
Defect chemistries of metal-doped CeO2 catalysts have attracted extensive scientific interests in heterogeneous catalysis. Here, we report the structure–activity relationship of CeO2 catalysts doped ...by Pr. The Pr-doped CeO2 solid solution catalysts were prepared by a coprecipitation method and evaluated in Prins condensation–hydrolysis of isobutene with formalin to 3-methyl-1,3-butanediol. Raman and infrared (IR) spectroscopies were used to characterize the defect sites of the catalysts. Pr creates two kinds of defects in Pr-doped CeO2: oxygen vacancy and lattice distortion (Pr3+O8-type complex, which was confirmed by the Raman and XPS spectra), whose concentrations depend on the Pr doping amount. The relationship between defect properties (type and concentration) and their catalytic consequence is established. The catalytic performance significantly depends on the oxygen vacancy concentration in Pr-doped CeO2 catalysts. This study also shows that a Pr3+O8-type complex has little effect on the catalytic performance, indicating that the Pr3+O8-type complex is a spectator during the reaction. DFT calculations have indicated that the oxygen vacancy induced by the Pr dopant on a CeO2 surface promotes the adsorption of HCHO and inhibits the adsorption of isobutene, suggesting the condensation of HCHO and isobutene occurs via an Eley–Rideal (ER) mechanism.
Summary
Background
Overweight or obesity is increasingly recognized as a possible risk factor for childhood asthma.
Objectives
We aimed to meta‐analyse the association between overweight or obesity ...and the risk for childhood asthma and wheeze and meanwhile explore potential causes of between‐study heterogeneity.
Methods
Literature search, study selection, and data extraction were performed independently and in duplicate. Data were analysed by STATA software.
Results
Eighteen articles and 73 252 children were analysed. In overall analyses, there was a significant association between overweight or obesity and the risk for childhood asthma (odds ratio OR = 1.30; 95% confidence interval CI, 1.23‐1.39; P < 0.001) and wheeze (OR = 1.90; 95% CI, 1.38‐2.63; P < 0.001), with none/marginal publication bias as revealed by the Egger test (P = 0.938/0.038), respectively. Subgroup analyses showed that children with obesity (OR = 1.40; 95% CI, 1.29‐1.52) were more likely to have asthma than children with overweight (OR = 1.22; 95% CI, 1.14‐1.31), and in children with overweight or obesity, girls (OR = 1.34; 95% CI, 1.16‐1.56) were more likely to have asthma than boys (OR = 1.27; 95% CI, 1.15‐1.40).
Conclusions
Our findings indicate that overweight or obesity is a significant risk factor for childhood asthma and wheeze and in children with overweight or obesity, the risk is more evident in girls than in boys.
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