Impacts of sea-land and mountain-valley circulations on the air pollution in Beijing-Tianjin-Hebei (BTH): A case study

In the study, observational data analyses and the WRF-CHEM model simulations are used to investigate the role of sea-land and mountain-valley breeze circulations in a severe air pollution event occurred in Beijing-Tianjin-Hebei (BTH) during August 9-10, 2013. Both the wind observations and the model simulations have clearly indicated the evolution of the sea-land and mountain-valley breeze circulations during the event. The WRF-CHEM model generally reproduces the local meteorological circulations and also performs well in simulating temporal variations and spatial distributions of fine particulate matters (PM2.5) and ozone (O-3) concentrations compared to observations in BTH. The model results have shown that the offshore land breeze transports the pollutants formed in Shandong province to the Bohai Gulf in the morning, causing the formation of high O-3 and PM2.5 concentrations over the gulf. The onshore sea breeze not only causes the formation of a convergence zone to induce upward movement, mitigating the surface pollution to some degree, also recirculates the pollutants over the gulf to deteriorate the air quality in the coastal area. The upward valley breeze brings the pollutants in the urban area of Beijing to the mountain area in the afternoon, and the downward mountain breeze transports the pollutants back during nighttime. The intensity of the mountain-valley breeze circulation is weak compared to the land-sea breeze circulation in BTH. It is worth noting that the local circulations play an important role when the large-scale meteorological conditions are relatively weak. (C) 2017 Elsevier Ltd. All rights reserved

Cultivation of Artificial Algal Crust and Its Effect on Soil Improvement in Sandy Area

Algae are the pioneer species of biological soil crusts. Cyanobacteria, microschwannophyta and pseudocladophyta can form fixed quicksand algae crusts on the surface of sand surface. Through artificial culture, soil crusts can be formed in a short time. The development and succession of algeal-sand crust promoted the enrichment of nutrients in the sand surface layer, and created conditions for the reproduction of micro-soil organisms and the colonization of herbaceous plants, thus promoting the desert ecosystem to enter a virtuous cycle. This chapter will focus on the cultivation process of artificial soil crust and its effect on soil improvement (soil organic matter and nitrogen) in sandy areas. In conclusion, the application of algal solution can rapidly form algal crusts, and according to the research results, the formation of algal crusts can significantly improve the chemical and biological properties of soil

Synthesis, biological evaluation, and physicochemical property assessment of 4-substituted 2-phenylaminoquinazolines as Mer tyrosine kinase inhibitors

Current results identified 4-substituted 2-phenylaminoquinazoline compounds as novel Mer tyrosine kinase (Mer TK) inhibitors with a new scaffold. Twenty-one 2,4-disubstituted quinazolines (series 4-7) were designed, synthesized, and evaluated against Mer TK and a panel of human tumor cell lines aimed at exploring new Mer TK inhibitors as novel potential antitumor agents. A new lead, 4b, was discovered with a good balance between high potency (IC50 0.68μM) in the Mer TK assay and antiproliferative activity against MV4-11 (GI50 8.54μM), as well as other human tumor cell lines (GI50<20μM), and a desirable druglike property profile with low logP value (2.54) and high aqueous solubility (95.6μg/mL). Molecular modeling elucidated an expected binding mode of 4b with Mer TK and necessary interactions between them, thus supporting the hypothesis that Mer TK might be a biologic target of this kind of new active compound

Optimization of a Fuel Assembly for Supercritical Water-Cooled Reactor CSR1000

As one of the Generation IV nuclear reactors, the SCWR (supercritical water-cooled reactor) has high economy and safety margin, good mechanical properties for its high thermal efficiency, and simplified structure design. As the key component of nuclear reactor, the fuel assembly has always been the main issue for the design of the SCWR. The design of the fuel assembly for CSR1000 proposed by the Nuclear Power Institute of China (NPIC) has been optimized and presented in this study, which is composed of four subassemblies welded by four filler strips and guide thimbles arranged close together in the cross-shaped passage. Aiming at improving the hydraulic buffer performance of the cruciform control rod, the scram time and terminal velocity of control rod assembly were calculated to assess the scram performance based on the computational fluid dynamics and dynamic mesh method, and the mechanical property and neutronic performance of assemblies were also investigated. It has been demonstrated that the optimized fuel assembly had good feasibility and performance, which was a promising design for CSR1000

Optimization of 4-( N -Cycloamino)phenylquinazolines as a Novel Class of Tubulin-Polymerization Inhibitors Targeting the Colchicine Site

The 6-methoxy-1,2,3,4-tetrahydroquinoline moiety in prior leads 2-chloro- and 2-methyl-4-(6-methoxy-3,4-dihydroquinolin-1(2H)-yl)quinazoline (1a and 1b) was modified to produce 4-(N-cycloamino)quinazolines (4a–c and 5a–m). The new compounds were evaluated in cytotoxicity and tubulin inhibition assays, resulting in the discovery of new tubulin-polymerization inhibitors. 7-Methoxy-4-(2-methylquinazolin-4-yl)-3,4-dihydroquinoxalin- 2(1H)-one (5f), the most potent compound, exhibited high in vitro cytotoxic activity (GI50 1.9–3.2 nM), significant potency against tubulin assembly (IC50 0.77 μM), and substantial inhibition of colchicine binding (99% at 5 μM). In mechanism studies, 5f caused cell arrest in G2/M phase, disrupted microtubule formation, and competed mostly at the colchicine site on tubulin. Compound 5f and N-methylated analogue 5g were evaluated in nude mouse MCF7 xenograft models to validate their antitumor activity. Compound 5g displayed significant in vivo activity (tumor inhibitory rate 51%) at a dose of 4 mg/kg without obvious toxicity, whereas 5f unexpectedly resulted in toxicity and death at the same dose

Hypergolic coordination compounds as modifiers for ionic liquid propulsion

Ionic liquids (ILs) have been regarded as green hypergolic materials since 2008, and hundreds of hypergolic ionic liquids have been reported thus far. However, only few have been proved to meet practical applications, due to their complex preparation technology and long hypergolic ignition delay (ID). Herein, to improve the properties of hypergolic ignition of ILs, we demonstrate a new design strategy of hypergolic coordination compounds (HCCs). Eight HCCs were synthesized based on two commonly used hypergolic ILs components (imidazolium = IM, dicyanamide = DCA) and four transition metal ions (Mn, Co, Ni, Cu) and were characterized through infrared spectroscopy, X-ray powder diffraction, and single-crystal X-ray diffraction. The experimental results showed that these HCCs exhibited excellent hypergolic ignition properties, and the ignition and combustion properties could be modulated by changing the metal, ligand, and anion. Additionally, the effects of HCCs on the ignition and combustion of organic hypergolic IL were investigated. The Cu-based HCCs showed the best performance among these new hypergolic materials. Compared with the HCCs-free IL, the IL system with 5% of [Cu(AIM)4] (DCA)2 exhibited a sharp reduction in the ID time of 1-allyl-3-methylimidazolium dicyanamide (AMIMDCA) (6 ms vs. 45 ms)

Retention of early-spring nitrogen in temperate grasslands: The dynamics of ammonium and nitrate nitrogen differ

In nitrogen (N)-limited temperate regions, winter is an important period of N accumulation. The accumulated N is released during snowmelt and thawing, and the availability peaks in early spring. However, the early-spring dynamics of specific N forms (i.e., ammonium NH4+ and nitrate NO3-) in temperate grasslands are still not fully understood. Here, we added (NH4+)-N-15 and (NO3-)-N-15 (equivalent to 150 mg (15)Nm(-2)) to the soils of a meadow steppe and a typical steppe in northern China immediately after snowmelt, then quantified the retention dynamics of (NH4+)-N-15 and (NO3-)-N-15 in soils, microbes, and plants over the subsequent growing season. Approximately 70% of the added N-15 tracers were initially retained within the soil-microbe-plant systems in both temperate grasslands. In early spring, much N-15 was immobilized in soils and microbes, while little had been taken up by plants. During the subsequent growing season, approximately 45% of the N-15 was rapidly lost by the soils and microbes, but plant N-15 acquisition gradually increased. Although soils and plants retained similar levels of (NH4+)-N-15 and (NO3-)-N-15 during the growing season, soil microbes retained more (NH4+)-N-15 than (NO3-)-N-15. Different plant taxa had distinct N-15 acquisition capacities: perennial grasses and forbs accumulated the N-15 tracers rapidly, while annuals did not. Perennial grasses were effective immobilizers of the (NH4+)-N-15, whereas forbs were effective immobilizers of the (NO3-)-N-15. These findings provided evidence of the substantial retention of early-spring N over the following growing season in temperate grasslands, regardless of the vegetation type and N form. However, it was clear that the dynamics of early-spring (NH4+)-N-15 and (NO3-)-N-15 differed within the soil-microbe-plant systems. (C) 2020 The Authors. Published by Elsevier B.V

The Effects of Breastfeeding for Four Months on Thinness, Overweight, and Obesity in Children Aged 3 to 6 Years: A Retrospective Cohort Study from National Physical Fitness Surveillance of Jiangsu Province, China

Objective: To explore the effects of breastfeeding during the first four months of life on thinness, overweight, and obesity and to analyze the influential factors in children aged three to six years in eastern China. Methods: This study was designed as a retrospective cohort study, and the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines were followed. A total of 8053 subjects were included in this secondary analysis of data from the 2015 “Physical Fitness Surveillance data of Jiangsu, China”. The subjects were classified into three groups on the basis of feeding patterns: breastfeeding, mixed feeding, and formula feeding. The International Obesity Task Force (IOTF) definitions of BMI were used to define thinness, overweight, and obesity. Multivariate logistic regression models and subgroup analysis were used to assess the association between feeding patterns and childhood thinness, overweight, obesity, and overweight/obesity, adjusted for potential confounders (sex, age grade, area, region/economy, gestational age, birthweight, childbearing age, mother’s education, and caretaker). Results: The prevalence of breastfeeding was 63.8%, and the prevalence of thinness, overweight, obesity, and overweight/obesity reached 2.7%, 11.2%, 4.7%, and 15.9%, respectively. Breastfeeding participants had a lower risk of overweight and overweight/obesity with adjusted ORs of 0.652 (95% CI: 0.533, 0.797; p p p > 0.05) compared with formula feeding. There was no statistical difference between mixed and formula feeding, in terms of thinness, overweight, obesity, or overweight/obesity (all p > 0.05). Subgroup analysis showed that breastfeeding for three years, preterm, and a childbearing age of 25–29 years had higher adjusted ORs for thinness, and in 5–6 years, urban areas, southern/developed economy regions, post-mature, childbearing age ≥ 25 years, and other caretakers had higher and invalid breastfeeding-adjusted ORs (all p > 0.05 except overweight in the urban grade) for both overweight and overweight/obesity. Conclusions: Breastfeeding during the first four months was not associated with the thinness of children aged 3–6 years in eastern China, and the protective effect of breastfeeding against overweight or overweight/obesity could be confirmed. However, the effects of breastfeeding on thinness, overweight, and obesity may change or become invalid in some subgroups, suggesting that there may be potential interactions between feeding patterns and influential factors

Factors and pathways of non-suicidal self-injury in children: insights from computational causal analysis

BackgroundNon-suicidal self-injury (NSSI) has become a significant public health issue, especially prevalent among adolescents. The complexity and multifactorial nature of NSSI necessitate a comprehensive understanding of its underlying causal factors. This research leverages the causal discovery methodology to explore these causal associations in children.MethodsAn observational dataset was scrutinized using the causal discovery method, particularly employing the constraint-based approach. By integrating machine learning and causal inference techniques, the study aimed to determine direct causal relationships associated with NSSI. The robustness of the causal relationships was evaluated using three methods to construct and validate it: the PC (Peter and Clark) method, Fast Causal Inference (FCI) method, and the GAE (Graphical Autoencoder) method.ResultsAnalysis identified nine nodes with direct causal relationships to NSSI, including life satisfaction, depression, family dysfunction, sugary beverage consumption, PYD (positive youth development), internet addiction, COVID-19 related PTSD, academic anxiety, and sleep duration. Four principal causal pathways were identified, highlighting the roles of lockdown-induced lifestyle changes, screen time, positive adolescent development, and family dynamics in influencing NSSI risk.ConclusionsAn in-depth analysis of the factors leading to Non-Suicidal Self-Injury (NSSI), highlighting the intricate connections among individual, family, and pandemic-related influences. The results, derived from computational causal analysis, underscore the critical need for targeted interventions that tackle these diverse causative factors

Strong non-growing season N uptake by deciduous trees in a temperate forest: A N-15 isotopic experiment

Nitrogen (N) is a critical element for vegetation growth and subsequent carbon (C) and nutrient cycling in terrestrial ecosystems. Plant N uptake, the only pathway for plants to directly obtain N from soils, is a bottleneck process for ecosystem C and N cycling. Ecological theories predict that deciduous trees remain dormant and do not take up N during winters as no growth occurs during this season. In this study, we adopted a N-15 isotopic experiment to trace N processes throughout the non-growing season in a temperate forest in northern China. The N-15-labelled inorganic N (NH4+ and NO3-) and (CN)-C-13-N-15-labelled organic N (glycine and tyrosine; equivalent to 150 mg N-15/m(2)) were applied to soils at mid-fall, and the N-15 recovery in various components of dominant evergreen and deciduous species was analysed. We found that soil N transformation remained active in the winter and microbial N immobilization reached its peak in late winter. Surprisingly, deciduous species maintained a high N uptake that was comparable with the evergreen species throughout the non-growing season. Perennial herbs did not take up N until the next spring. All plant species acquired inorganic N and simple amino acids, while only the tree species utilized complex amino acids. Throughout the non-growing season, evergreen and deciduous trees showed higher uptake rates for NH4+ and glycine than NO3- and tyrosine, while deciduous shrubs and herbs showed a stronger preference for NO3- over other N forms. Synthesis. The finding that deciduous trees have strong N uptake in the non-growing season challenges the conventional viewpoint that deciduous trees remain dormant during non-growing seasons. This mechanism might supplement the algorithm in the model representation of N-limited temperate forest ecosystems