A Nationwide Nitrogen Deposition Monitoring Network (NNDMN) containing 43 monitoring sites was established in China to measure gaseous NH3, NO2, and HNO3 and particulate NH4+ and NO3− in air and/or ...precipitation from 2010 to 2014. Wet/bulk deposition fluxes of Nr species were collected by precipitation gauge method and measured by continuous-flow analyzer; dry deposition fluxes were estimated using airborne concentration measurements and inferential models. Our observations reveal large spatial variations of atmospheric Nr concentrations and dry and wet/bulk Nr deposition. On a national basis, the annual average concentrations (1.3–47.0 μg N m−3) and dry plus wet/bulk deposition fluxes (2.9–83.3 kg N ha−1 yr−1) of inorganic Nr species are ranked by land use as urban > rural > background sites and by regions as north China > southeast China > southwest China > northeast China > northwest China > Tibetan Plateau, reflecting the impact of anthropogenic Nr emission. Average dry and wet/bulk N deposition fluxes were 20.6 ± 11.2 (mean ± standard deviation) and 19.3 ± 9.2 kg N ha−1 yr−1 across China, with reduced N deposition dominating both dry and wet/bulk deposition. Our results suggest atmospheric dry N deposition is equally important to wet/bulk N deposition at the national scale. Therefore, both deposition forms should be included when considering the impacts of N deposition on environment and ecosystem health.
As the amount of reactive nitrogen (N) generated and emitted increases the amount of N deposition and its contribution to eutrophication or harmful algal blooms in the coastal zones are becoming ...issues of environmental concern. To quantify N deposition in coastal seas of China we selected six typical coastal sites from North to South in 2011. Concentrations of NH3, HNO3, NO2, particulate NH4+ (pNH4+) and pNO3− ranged from 1.97- 4.88, 0.46 -1.22, 3.03 -7.09, 2.24 - 4.90 and 1.13-2.63 g N m−3 at Dalian (DL), Changdao (CD), Linshandao (LS), Fenghua (FH), Fuzhou (FZ), and Zhanjiang (ZJ) sites, respectively. Volume-weighted NO3−-N and NH4+-N concentrations in precipitation varied from 0.46 to 1.67 and 0.47 to 1.31 mg N L−1 at the six sites. Dry, wet and total deposition rates of N were 7.8-23.1, 14.2-25.2 and 22.0 - 44.6 kg N ha−1 yr−1 across the six coastal sites. Average N dry deposition accounted for 45.4% of the total deposition and NH3 and pNH4+ contributed to 76.6% of the dry deposition. If we extrapolate our total N deposition of 33.9 kg N ha−1 yr−1 to the whole Chinese coastal sea area (0.40 million km2), total N deposition amounts to 1.36 Tg N yr−1, a large external N input to surrounding marine ecosystems.
Ampelopsis grossedentata, an indigenous plant in southern China, has been used for treating pharyngitis in traditional Chinese medicine for hundreds of years. In this study, we explored the ...anti-inflammatory activity of dihydromyricetin (1), its major bioactive component, and the underlying mechanism of this action. We demonstrated that 1 suppressed the levels of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) as well as increased the level of the anti-inflammatory cytokine interleukin-10 (IL-10) in lipopolysaccharide (LPS)-treated mice. Moreover, 1 was found to markedly inhibit the production of nitric oxide (NO) and the levels of TNF-α, IL-1β, and IL-6, whereas it increased the level of IL-10 in LPS-induced RAW 264.7 macrophage cells. Compound 1 also reduced the protein expression of inducible nitric oxide synthase (iNOS), TNF-α, and cyclooxygenase-2 (COX-2) in macrophage cells. Furthermore, 1 suppressed the phosphorylation of NF-kappa B (NF-κB) and IκBα as well as the phosphorylation of p38 and JNK but not ERK1/2 in LPS-stimulated macrophages. Taken together, the present results suggest that 1 exerts its topical anti-inflammatory action through suppressing the activation of NF-κB and the phosphorylation of p38 and JNK. Thus, 1 may be a potentially useful therapeutic agent for inflammatory-related diseases.
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IJS, KILJ, NUK, PNG, UL, UM
Most cancers are due to modifiable lifestyle and environmental risk factors, and are potentially preventable. No studies have provided a systematic quantitative assessment of the burden of cancer ...mortality and incidence attributable to known risk factors in China.
We calculated the proportions of cancer deaths and new cases attributable to known risk factors in China, based on the prevalence of exposure around 1990 and national data on cancer mortality and incidence for the year 2005.
Chronic infection is the main risk factor for cancer in China, accounting for 29.4% of cancer deaths (31.7% in men and 25.3% in women), followed by tobacco smoking (22.6% with 32.7% in men and 5.0% in women), low fruit intake (13.0%), alcohol drinking (4.4%), low vegetable intake (3.6%) and occupational exposures (2.7%). The remaining factors, including environmental agents, physical inactivity, the use of exogenous hormones and reproductive factors are each responsible for <1.0%.
Modifiable risk factors explain nearly 60% of cancer deaths in China, with a predominant role of chronic infection and tobacco smoking. Our findings could provide a basis for cancer prevention and control programs aimed at reducing cancer risk in other developing countries.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Early detection of cancer offers the opportunity to identify candidates when curative treatments are achievable. The THUNDER study (THe UNintrusive Detection of EaRly-stage cancers, NCT04820868) ...aimed to evaluate the performance of enhanced linear-splinter amplification sequencing, a previously described cell-free DNA (cfDNA) methylation-based technology, in the early detection and localization of six types of cancers in the colorectum, esophagus, liver, lung, ovary, and pancreas.
A customized panel of 161 984 CpG sites was constructed and validated by public and in-house (cancer: n = 249; non-cancer: n = 288) methylome data, respectively. The cfDNA samples from 1693 participants (cancer: n = 735; non-cancer: n = 958) were retrospectively collected to train and validate two multi-cancer detection blood test (MCDBT-1/2) models for different clinical scenarios. The models were validated on a prospective and independent cohort of age-matched 1010 participants (cancer: n = 505; non-cancer: n = 505). Simulation using the cancer incidence in China was applied to infer stage shift and survival benefits to demonstrate the potential utility of the models in the real world.
MCDBT-1 yielded a sensitivity of 69.1% (64.8%-73.3%), a specificity of 98.9% (97.6%-99.7%), and tissue origin accuracy of 83.2% (78.7%-87.1%) in the independent validation set. For early-stage (I-III) patients, the sensitivity of MCDBT-1 was 59.8% (54.4%-65.0%). In the real-world simulation, MCDBT-1 achieved a sensitivity of 70.6% in detecting the six cancers, thus decreasing late-stage incidence by 38.7%-46.4%, and increasing 5-year survival rate by 33.1%-40.4%, respectively. In parallel, MCDBT-2 was generated at a slightly low specificity of 95.1% (92.8%-96.9%) but a higher sensitivity of 75.1% (71.9%-79.8%) than MCDBT-1 for populations at relatively high risk of cancers, and also had ideal performance.
In this large-scale clinical validation study, MCDBT-1/2 models showed high sensitivity, specificity, and accuracy of predicted origin in detecting six types of cancers.
•MCDBT-1 had a sensitivity of 69.1% and a specificity of 98.9% in detecting six cancers.•In the real world, MCDBT-1 decreased late-stage incidence by 38.7%-46.4% and increased 5-year survival rate by 33.1%-40.4%.•In parallel, MCDBT-2 was set at a lower specificity but a higher sensitivity than MCDBT-1 and had an ideal performance.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
► Medium manganese steel. ► Intercritical annealing treatment. ► Large fractioned austenite. ► Excellent mechanical properties. ► Enhanced TRIP effects.
Microstructure and mechanical properties of ...medium manganese steel (Fe–0.2C–5Mn) processed by annealing at 650
°C with annealing time up to 12
h after accelerated cooling were studied. It was found that the martensite structure was gradually transformed into a superfine ferrite and austenite duplex structure by austenite reverted transformation during annealing process. The annealing heat treatment results in a large volume fraction of austenite (34%) and an excellent combination of ultimate tensile strength (∼1000
MPa) and total elongation (>40%) at room temperature. The ultrahigh tensile strength and improved ductility of present steel were mainly attributed to the enhanced phase transformation induced plasticity due to the large fractioned austenite.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Carbon nanotube (CNTs) reinforced Mg matrix composites were successfully fabricated by a novel approach. After hot extrusion, the influence of CNTs on microstructure and mechanical properties of ...Mg–6Zn matrix was investigated. The results showed that most CNTs distributed uniformly and individually in the composites, and good interfacial bonding was achieved. CNTs significantly refined the grains of Mg–6Zn matrix, and the CNTs evidently improved the ultimate tensile strength (UTS), yield strength (YS) and Young's modulus. Grain refinement, load transfer mechanism and Orowan strengthening mechanism play important roles on the increase of the yield strength.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Recently, the +2 formal oxidation state in soluble molecular complexes for lanthanides (La-Nd, Sm-Lu) and actinides (Th and U) has been discovered W. J. Evans, et al., J. Am. Chem. Soc., 2011, 133, ...15914; J. Am. Chem. Soc., 2012, 134, 8420; J. Am. Chem. Soc., 2013, 135, 13310; Chem. Sci., 2015, 6, 517. To explore the nature of the bonding and stabilities of the low-valent actinide complexes, a series of divalent actinide species, AnCp'3(-) (Andouble bond, length as m-dashTh-Am, Cp' = η(5)-C5H4(SiMe3)(-)) have been investigated in THF solution using scalar relativistic density functional theory. The electronic structures and electron affinity properties were systematically studied to identify the interactions between the +2 actinide ions and Cp' ligands. The ground state electron configurations for the AnCp'3(-) species are ThCp'3(-) 6d(2), PaCp'3(-) 5f(2)6d(1), UCp'3(-) 5f(3)6d(1), NpCp'3(-) 5f(5), PuCp'3(-) 5f(6), and AmCp'3(-) 5f(7), respectively, according to the MO analysis. The total bonding energy decreases from the Th- to the Am-complex and the electrostatic interactions mainly dominate the bonding between the actinide atom and ligands. The electron affinity analysis suggests that the reduction reaction of AnCp'3→ AnCp'3(-) should become increasingly facile across the actinide series from Th to Am, in accord with the known An(iii/ii) reduction potentials. This work expands the knowledge on the low oxidation state chemistry of actinides, and further motivates and guides the synthesis of related low oxidation state compounds of 5f elements.
All the Li metal anode-based batteries suffer from a high propensity to form Li dendrites. To prevent the formation of dendritic lithium on the electrodes, amorphous carbon coatings are deposited ...onto the surface of metallic lithium foil by magnetron sputtering technique. The electrochemical performances of the amorphous carbon-coated lithium (Li/C) electrodes are investigated by galvanostatic charge/discharge tests, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The compact carbon coatings on the surface of lithium foil can suppress the growth of dendritic lithium during charge–discharge process. The thickness of amorphous carbon coating affects the electrode from two aspects; the thick coating can prevent the formation of dendritic lithium much efficiently, but lead to a large impedance of Li+ transfer.
•Amorphous carbon coatings were deposited onto the surface of metallic lithium.•The formation of dendritic can be prevented according to the SEM photograph.•The electrochemical performance is promoted due to the existence of a-C coating.•The thickness of a-C coating affects the electrode performance from two aspects.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We report a first-principles study on the electronic structures of deformed graphene nanoribbons (GNRs). Our theoretical results show that the electronic properties of zigzag GNRs are not sensitive ...to uniaxial strain, while the energy gap modification of armchair GNRs (AGNRs) as a function of uniaxial strain displays a nonmonotonic relationship with a zigzag pattern. The subband spacings and spatial distributions of the AGNRs can be tuned by applying an external strain. Scanning tunneling microscopy dI/dV maps can be used to characterize the nature of the strain states, compressive or tensile, of AGNRs. In addition, we find that the nearest neighbor hopping integrals between pi-orbitals of carbon atoms are responsible for energy gap modification under uniaxial strain based on our tight binding approximation simulations.
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