Heterogeneous catalysts of inexpensive and reusable transition-metal are attractive alternatives to homogeneous catalysts; the relatively low activity of transition-metal nanoparticles has become the ...main hurdle for their practical applications. Here, the de novo design of a Mott–Schottky-type heterogeneous catalyst is reported to boost the activity of a transition-metal nanocatalyst through electron transfer at the metal/nitrogen-doped carbon interface. The Mott–Schottky catalyst of nitrogen-rich carbon-coated cobalt nanoparticles (Co@NC) was prepared through direct polycondensation of simple organic molecules and inorganic metal salts in the presence of g-C3N4 powder. The Co@NC with controllable nitrogen content and thus tunable Fermi energy and catalytic activity exhibited a high turnover frequency (TOF) value (8.12 mol methyl benzoate mol–1 Co h–1) for the direct, base-free, aerobic oxidation of benzyl alcohols to methyl benzoate; this TOF is 30-fold higher than those of the state-of-the-art transition-metal-based nanocatalysts reported in the literature. The presented efficient Mott–Schottky catalyst can trigger the synthesis of a series of alkyl esters and even diesters in high yields.
This paper presented a systematic study of microstructure and mechanical properties of Cu/Fe explosive-bonded interfaces. The periodic wavy bonding structure with both vortex region and solid-solid ...bonding region was embedded in the interface. Typical annealing twin structures were observed in the texture and orientation analysis of Cu matrix. The ASBs filled with some much smaller size equiaxed grains and orientation variations in different areas were found in the Fe matrix. The transition layer consisted of nano-sized grains of 60 nm was formed between the copper and steel plate. The microindentation results showed that the hardness of the interface (330.9 MPa) and deformation area (Cu 100 HV and Fe 286.8 HV) was higher than the matrix regions. The higher hardness of the transition layer (15.707 GPa) determined by nanoindentation analysis was explained by the existence of nanocrystallines in this zone. The induced tensile tests showed that the cracks didn’t extent along the interface wave structure but inside the copper matrix, reflecting the high quality of the bonding.
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•Copper-steel composite plates were successfully fabricated by explosive welding.•Microstructure in the interface was investigated.•The texture and orientation analysis of the interface was carried out by EBSD.•Nanoindentation tests were performed to determine mechanical properties in transition layer.
Surface sediment samples collected from 19 sites in the Liaohe River protected area were analysed for heavy metals to evaluate their potential ecological risk. The results demonstrated that the ...degree of pollution from seven heavy metals decreases in the following sequence: cadmium(Cd)>arsenic(As)>copper(Cu)>nickel(Ni)>lead(Pb)>chromium(Cr)>zinc(Zn). The metal speciation analysis indicated that Cd, Pb and Zn were dominated by non-residual fractions and have high mobility and bioavailability, indicating significant anthropogenic sources. Based on the potential ecological risk index (PERI), geo-accumulation index (Igeo) and risk assessment code (RAC), Cd made the most dominant contribution, with a high to very high potential ecological risk being determined in this studied area. Moreover, in reference to the results of multivariate statistical analyses, we deduced that Cd and Zn originated from agriculture sources within the Liaohe River protected area, whereas Cu, Cr and Ni primarily originated from natural sources.
•Speciation analysis showed that Cd, Pb and Zn have high bioavailability.•PCA revealed that Cd and Zn were mainly from agriculture sources.•Cd posed higher potential ecological risk in this studied area.
ObjectiveTo profile gut microbiome-associated metabolites in serum and investigate whether these metabolites could distinguish individuals with colorectal cancer (CRC) or adenoma from normal healthy ...individuals.DesignIntegrated analysis of untargeted serum metabolomics by liquid chromatography-mass spectrometry and metagenome sequencing of paired faecal samples was applied to identify gut microbiome-associated metabolites with significantly altered abundance in patients with CRC and adenoma. The ability of these metabolites to discriminate between CRC and colorectal adenoma was tested by targeted metabolomic analysis. A model based on gut microbiome-associated metabolites was established and evaluated in an independent validation cohort.ResultsIn total, 885 serum metabolites were significantly altered in both CRC and adenoma, including eight gut microbiome-associated serum metabolites (GMSM panel) that were reproducibly detected by both targeted and untargeted metabolomics analysis and accurately discriminated CRC and adenoma from normal samples. A GMSM panel-based model to predict CRC and colorectal adenoma yielded an area under the curve (AUC) of 0.98 (95% CI 0.94 to 1.00) in the modelling cohort and an AUC of 0.92 (83.5% sensitivity, 84.9% specificity) in the validation cohort. The GMSM model was significantly superior to the clinical marker carcinoembryonic antigen among samples within the validation cohort (AUC 0.92 vs 0.72) and also showed promising diagnostic accuracy for adenomas (AUC=0.84) and early-stage CRC (AUC=0.93).ConclusionGut microbiome reprogramming in patients with CRC is associated with alterations of the serum metabolome, and GMSMs have potential applications for CRC and adenoma detection.
•Anthocyanin derivatives’ evolution pattern during wine aging was elucidated.•Color contribution of anthocyanin derivatives in various aging stage was clarified.•Pinotin, A-v-F and vitisin A ...contribute to wine prolonged aging color greatly.•Machine learning methods showed good predictive performance on wine aging stage.
Anthocyanin derivatives and chromatic characteristics of 234 different-vintage red wine were investigated based on a targeted HPLC-MS/MS and CIELAB approach. The K-means cluster analysis showed that the evolution pattern varies amongst anthocyanin derivative classes. Their stabilities are: pinotins > flavanyl-pyranoanthocyanins, vitisin A > monomeric anthocyanin, direct anthocyanin-flavan-3-ols condensation products > vitisin B, anthocyanin ethyl-linked flavan-3-ols products. The proportion of most pyranoanthocyanins becomes more significant among all detected anthocyanin derivatives during wine aging, whereas flavanols-related anthocyanin derivatives (except for flavanyl-pyranoanthocyanins) decreased drastically. PLSR showed that aging tawny characteristics is related to pyranoanthocyanins except for vitisin B, especially pinotins, whereas monomeric anthocyanins and flavanol-related derivates (except for flavanyl-pyranoanthocyanins) contribute to red violet color. But aging color density is more associated with the content of vitisin A and flavanyl-pyranoanthocyanins. Two predictive models based on random forest and support vector machine modeling showed good performance in predicting the extent of wine aging.
Although organic photovoltaic (OPV) cells have many advantages, their performance still lags far behind that of other photovoltaic platforms. A fundamental reason for their low performance is the low ...charge mobility of organic materials, leading to a limit on the active-layer thickness and efficient light absorption. In this work, guided by a semi-empirical model analysis and using the tandem cell strategy to overcome such issues, and taking advantage of the high diversity and easily tunable band structure of organic materials, a record and certified 17.29% power conversion efficiency for a two-terminal monolithic solution-processed tandem OPV is achieved.
The “macrotrabecular-massive” (MTM) pattern of hepatocellular carcinoma (HCC) has been suggested to represent a distinct HCC subtype and is associated with specific molecular features. Since the ...immune microenvironment is heterogenous in HCC, it is important to evaluate the immune microenvironment of this novel variant. CMTM6, a key regulator of PD-L1, is an important immunocheckpoint inhibitor. This study aimed to evaluate the prognostic effect of CMTM6/PD-L1 coexpression and its relationship with inflammatory cells in HCC. We analyzed 619 HCC patients and tumors were classified into MTM and non-MTM HCC subtypes. The expression levels of CMTM6 and PD-L1 in tumor and inflammatory cells were evaluated by immunohistochemistry. The density of inflammatory cells in the cancer cell nest was calculated. Tumoral PD-L1 expression and inflammatory cell density were higher in the MTM type than in the non-MTM type. CMTM6-high expression was significantly associated with shorter OS and DFS than CMTM6-low expression in the whole HCC patient population and the MTM HCC patient population. Moreover, MTM HCC patients with CMTM6/PD-L1 coexpression experienced a higher risk of HCC progression and death. In addition, CMTM6/PD-L1 coexpression was shown to be related to a high density of inflammatory cells. Notably, a new immune classification, based on CMTM6/PD-L1 coexpression and inflammatory cells, successfully stratified OS and DFS in MTM HCC. CMTM6/PD-L1 coexpression has an adverse effect on the prognosis of HCC patients, especially MTM HCC patients. Our study provides evidence for the combination of immune status assessment with anti-CMTM6 and anti-PD-L1 therapy in MTM HCC patients.
Two skeleton isomers, CaL(H2O)(DMF)2•DMF (1) (H2L=5‐(1,3‐dioxo‐1H‐benzodeisoquinolin‐2(3H)‐yl)isophthalic acid) with a 1 dimensional chain structure and CaL(DMF)1.72• (DMF)0.28 (2) with a 2 ...dimensional layer structure were synthesized. Mechanochromic luminescence studies reveal that 1 and 2 exhibit luminescent red‐shift and blue‐shift respectively under grinding stimuli. The different influence of grinding stimuli on the π⋅⋅⋅π interaction in the two structures are proposed to be the main reason for such different responses. In addition, 1 has a rare broad sensing ability for halogenated hydrocarbons and can distinguish seven halogenated hydrocarbons out of 17 solvents. 1 can also be used for rapid detection of trace water in DMF with a calculated detection limit of 0.0078 v/v %. The relevant recognition mechanism is the decomposition of the structure during the recognition process due to the water instability of the ionic bond. The above results reveal that both compounds have the potential to be used as multi‐stimulus‐responsive materials.
Present here are two framework isomers that exhibit grinding and volatile organic solvent stimulus response properties. In addition, one can also be used to detect H2O in DMF with detection limit of 0.0078 v/v%.
Oxygen vacancies can help to capture oxygen‐containing species and act as active centers for oxygen evolution reaction (OER). Unfortunately, effective methods for generating a high amount of oxygen ...vacancies on the surface of various nanocatalysts are rather limited. Here, we described an effective way to generate oxygen‐vacancy‐rich surface of transition metal oxides, exemplified with Co3O4, simply by constructing highly coupled interface of ultrafine Co3O4 nanocrystals and metallic Ti. Impressively, the amounts of oxygen vacancy on the surface of Co3O4/Ti surpassed the reported values of the Co3O4 modified even under highly critical conditions. The Co3O4/Ti electrode could provide a current density of 23 mA cm−2 at an OER overpotential of 570 mV, low Tafel slope, and excellent durability in neutral medium. Because of the formation of a large amount of oxygen vacancies as the active centers for OER on the surface, the TOF value of the Co3O4@Ti electrode was optimized to be 3238 h−1 at an OER overpotential of 570 mV, which is 380 times that of the state‐of‐the‐art non‐noble nanocatalysts in the literature.
Interface activation: An easy but effective approach to generating a rich amount of oxygen vacancies (VO) in Co3O4 nanocrystal‐based oxygen evolution reaction (OER) electrodes by constructing a highly coupled interface with metallic Ti is demonstrated. Oxygen vacancies help to capture water molecules for OER in neutral electrolyte, resulting in impressively high current density and TOF value at an OER overpotential of 570 mV.
Cohort evidence that links long-term exposures to air pollution and mortality comes largely from the United States and European countries. We investigated the relationship between long-term exposures ...to particulate matter <10μm in diameter (PM10), nitrogen dioxide (NO2), and sulfur dioxide (SO2) and mortality of lung cancer in Northern China. A cohort of 39,054 participants were followed during 1998–2009. Annual average concentrations for PM10, NO2, and SO2 were determined based on data collected from central monitoring stations. Lung cancer deaths (n=140) were obtained from death certificates, and hazard ratios (HRs) were estimated using Cox proportional hazards models, adjusting for age, gender, BMI, education, marital status, smoking status, passive smoking, occupation, alcohol consumption, etc. Each 10mg/m3 increase in PM10 concentrations was associated with a 3.4%–6.0% increase in lung cancer mortality in the time-varying exposure model and a 4.0%–13.6% increase in the baseline exposure model. In multi-pollutant models, the magnitude of associations was attenuated, most strongly for PM10. The association was different in men and women, also varying across age categories and different smoking status. Substantial differences exist in the risk estimates for participants based on assignment method for air pollution exposure.
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•The relationship between exposure to air pollution and lung cancer is proposed.•Levels of PM10 and SO2 were associated with lung cancer mortality independently.•The association was different in men and women, and varied across smoking status.
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