Search

Simple Summary: Native chickens generally have the characteristics of low growth performance, which has also become a limiting factor for the breeding of yellow feather broilers. More and more studies have shown that gut microbiota plays an important role in the growth of livestock farming. The Guizhou yellow chicken is a breed of yellow-feathered broiler chicken with excellent meat quality and good flavor currently being cultivated in Guizhou Province, China. In order to explore the role of gut microbiota on the growth performance of native chickens, the Guizhou yellow chicken was taken as a representative, and high-market-weight and low-market-weight chicken groups were established according to their market weights. By integrating microbial 16S rRNA gene sequencing and non-targeted serum metabolome data, five key cecal microbes associated with high body weight in chickens and one key microbe associated with low body weight were identified. In addition, the results also showed that specific gut microbes might positively affect the growth rate of chickens by regulating vitamin and other metabolic pathways. These findings might improve understanding of the role of gut microbiota in chicken growth traits and their underlying metabolic mechanisms. The gut microbiota plays an important role in the physiological activities of the host and affects the formation of important economic traits in livestock farming. The effects of cecal microbiota on chicken weights were investigated using the Guizhou yellow chicken as a model. Experimental cohorts from chickens with high- (HC, n = 16) and low-market-weights (LC, n = 16) were collected. Microbial 16S rRNA gene sequencing and non-targeted serum metabolome data were integrated to explore the effect and metabolic mechanism of cecal microbiota on market weight. The genera Lachnoclostridium, Alistipes, Negativibacillus, Sellimonas, and Ruminococcus torques were enriched in the HC group, while Phascolarctobacterium was enriched in the LC group (p < 0.05). Metabolomic analysis determined that pantothenic acid (vitamin B5), luvangetin (2H-1-benzopyran-6-acrylic acid), and menadione (vitamin K3) were significantly higher in HC serum, while beclomethasone dipropionate (a glucocorticoid) and chlorophene (2-benzyl-4-chlorophenol) were present at higher levels in the LC group. The microbes enriched in HC were significantly positively correlated with metabolites, including pantothenic acid and menadione, and negatively correlated with beclomethasone dipropionate and chlorophene. These results indicated that specific cecal bacteria in Guizhou yellow chickens alter the host metabolism and growth performance. This study provides a reference for revealing the mechanism of cecal microbe actions that affect chicken body weight. [ABSTRACT FROM AUTHOR]

Co‐doped CeO2 (Ce1‐xCoxO2, x = 0, 0.03, and 0.06) thin films were prepared by radio‐frequency magnetron sputtering. The structural, optical, and magnetic properties of these films were characterized by X‐ray diffraction (XRD), Raman spectroscopy (Raman), atomic force microscopy (AFM), Fourier transform‐infrared spectroscopy (FT‐IR), spectroscopic ellipsometry (SE), and superconducting quantum interference magnetometer (SQUID). XRD and Raman studies revealed that all the films exhibited single phase of cubic fluorite structure, with highly (111) preferred orientation. No Co and Co‐related oxide was detected. Compared with undoped CeO2 films, the defect concentration of Co‐doped films increases. AFM images displayed that the film surface morphology is dependent on the Co‐doped content. The vibrational band assignment of undoped and Co‐doped CeO2 films was analyzed by FT‐IR. The energy dispersion optical constants (the refractive index n and the extinction coefficient k) of Ce1‐xCoxO2 thin films were obtained by analyzing the SE spectra in the ultraviolet and visible‐near infrared (UV–NIR) region (0.5–5.9 eV). The optical band gap energies Eg for these films were determined. The Eg values of the Ce1‐xCoxO2 thin films are 3.35, 3.27, and 3.25 eV, and the n values at wavelength of 632 nm are about 2.35, 2.38, and 2.42 for Co‐doped content x = 0, 0.03, and 0.06, respectively. SQUID measurements show that Co‐doped CeO2 films exhibit room temperature ferromagnetism, and the saturation magnetization (Ms) is 0.0051 and 0.0098 emμ/cm3 with the Co doping content x = 0.03 and 0.06, respectively. The ferromagnetism of Co‐doped CeO2 films belong to the intrinsic magnetism of the films. [ABSTRACT FROM AUTHOR]

Single‐phase Ce0.97Co0.03O2 films are successfully deposited on Si(100) by radio‐frequency magnetron sputtering. The effects of substrate temperature on the structural and optical properties of Ce0.97Co0.03O2 films are investigated. X‐ray diffractometer (XRD) and Raman spectra confirm the formation of the pure CeO2 phase with highly (111) preferred orientation for all films. The crystallite size increases with increasing substrate temperature. Atomic force microscope (AFM) images of Ce0.97Co0.03O2 films exhibit dense and uniform microstructures with grain sizes of ≈18, 28, and 35 nm for substrate temperatures of 30, 500, and 700 °C, respectively. The surface roughness is increased from 1.49 to 6.72 nm with increase in substrate temperature. Emission at centers of 335, 350, 375, and 392 nm is observed in photoluminescence (PL) spectra. Emission peaks of all films with different substrate temperatures have similar shapes and different intensities. Optical characteristics are studied by spectroscopic ellipsometry (SE) in the UV−NIR region. The optical constants (n and k) are determined by analyzing the SE spectra. The results show that with increase in substrate temperature, the values of n and k increase, while the value of Eg decreases. The obtained results can serve as a database for the optical properties of Ce0.97Co0.03O2 films. [ABSTRACT FROM AUTHOR]

Deep neural networks (DNNs) are getting deeper and larger, making memory become one of the most important bottlenecks during training. Researchers have found that the feature maps generated during DNN training occupy the major portion of memory footprint. To reduce memory demand, they proposed to encode the feature maps in the forward pass and decode them in the backward pass. However, we observe that the execution of encoding and decoding is time-consuming, leading to severe slowdown of the DNN training. To solve this problem, we present an efficient parallel memory compression framework—EPMC, which enables us to simultaneously reduce the memory footprint and the impact of encoding/decoding on DNN training. Our framework employs pipeline parallel optimization and specific-layer parallelism for encoding and decoding to reduce their impact on overall training. It also combines precision reduction with encoding for improving the data compressing ratio. We evaluate EPMC across four state-of-the-art DNNs. Experimental results show that EPMC can reduce the memory footprint during training to 2.3 times on average without accuracy loss. In addition, it can reduce the DNN training time by more than 2.1 times on average compared with the unoptimized encoding/decoding scheme. Moreover, compared with using the common compression scheme Compressed Sparse Row, EPMC can achieve data compression ratio by 2.2 times. [ABSTRACT FROM AUTHOR]

Simple Summary: Growth traits are important economic traits of broilers. We found the key metabolites that may be related to the body weight of Wumeng black-bone chicken by comparing their serum metabolomics between the high- and low-weight groups. Metabolites with high levels in serum such as riboflavin and 2-isopropylmalic acid may be beneficial to growth performance, and the enrichment of inflammation-related metabolites may be related to low body weight of chickens. Our results can provide a certain reference for the analysis of metabolic mechanism of body-weight formation of chickens. Growth performance is an important economic trait of broilers but the related serum metabolomics remains unclear. In this study, we utilized non-targeted metabolomics using ultra-high-performance liquid phase tandem mass spectrometry (UHPLC-MS/MS) to establish metabolite profiling in the serum of Chinese Wumeng black-bone chickens. The biomarker metabolites in serum associated with growth performance of chickens were identified by comparing the serum metabolome differences between chickens that significantly differed in their weights at 160 days of age when fed identical diets. A total of 766 metabolites were identified including 13 differential metabolite classes such as lipids and lipid-like molecules, organic acids and their derivatives, and organoheterocyclic compounds. The results of difference analysis using a partial least squares discriminant analysis (PLS-DA) model indicated that the low-body-weight group could be differentiated based on inflammatory markers including prostaglandin a2, kynurenic acid and fatty acid esters of hydroxy fatty acids (FAHFA), and inflammation-related metabolic pathways including tryptophan and arachidonic acid metabolism. In contrast, the sera of high-body-weight chickens were enriched for riboflavin and 2-isopropylmalic acid and for metabolic pathways including riboflavin metabolism, acetyl group transfer into mitochondria, and the tricarboxylic acid (TCA) cycle. These results provide new insights into the practical application of improving the growth performance of local chickens. [ABSTRACT FROM AUTHOR]

A ratiometric fluorescence probe for robust and rapid Cu 2+ detection was established based on an electrostatic association complex of polyallylamine capped CdTe(S) quantum dots (CdTe(S)@PAI QDs) and a small molecule dye 5-oxo-3,5-dihydro-2H-thiazolo[3,2-a]pyridine-7-carboxylic acid (TPCA). Both of the components are easy to make. Strongly fluorescent CdTe(S)@PAI QDs could be simply prepared through a one-step UV irradiation while TPCA could be obtained directly through the hydrothermal method. The ratiometric probe was built through mixing of both components, neither organic solvent nor other harsh conditions is involved. The as-prepared probe shows dual-emission at 525 nm and 420 nm under excitation wavelength of 350 nm. The fluorescence ratio ( I 525nm /I 420nm ) remains constant with concentration changes of the complex up to ± 20% and a temperature variation from 20 to 50 °C, but shows significant change in the presence of Cu 2+ . The proposed probe exhibits excellent selectivity and sensitivity for Cu 2+ . The fluorescence ratio ( I 525nm /I 420nm ) show good linear relationship with the Cu 2+ concentration range from 0.05 to 1.6 μM and the limit of detection (S/N = 3) can reach 24 nM . Its applicability was demonstrated by detecting Cu 2+ ions in certified reference materials and real samples with recoveries in a range of 91.0–107.3%. [ABSTRACT FROM AUTHOR]

Fluorescent carbon nanoparticles (FCNPs) have been deeply researched and widely applied in recent years due to their good optics performance, chemical stability and biocompatibility. Herein, a green and rapid microwave-assisted solid-phase synthesis (solvent-free) approach was proposed for the fabrication of highly FCNPs in a very short period of time, 4 min. The as-prepared FCNPs can emit a blue emission with quantum yield of up to 63.2% in water solution and show yellow fluorescence in the solid state. The FCNPs also exhibit special solvent effect that the fluorescence emission can be adjusted by controlling the solvent ratio of ethanol and water. Most importantly, the FCNPs possess a narrow-range pH response. The probe responds linearly and rapidly to minor pH fluctuations within the range of 3.47–5.10 and the correlation coefficient is above 0.99. The proposed FCNPs also exhibit high photostability and reusability. As expected, the cell imaging and intracellular pH monitoring was achieved successfully in living SMMC 7721 hepatoma cells by this probe. The FCNPs is promising as a convenient and general fluorescent pH sensor for bioimaging applications. [ABSTRACT FROM AUTHOR]

N -Nitrosamines are strong carcinogens and widely existing in nature and human environment. Airborne N -nitrosamines are found in tobacco, rubber factories and heavily polluted areas with atmospheric particulate matter. In this paper, needle trap device, an extraction trap device with sorbent inside the needle, coupled with gas chromatography–mass spectrometry, was applied as an efficient and solvent-free method for the sampling and the determination of four volatile N -nitrosamines (i.e., N -nitrosodimethylamine, N -nitrosodiethylamine, N -nitrosodi- n -propylamine, and N -nitrosodi- n -butylamine) in the atmosphere. The extraction and desorption conditions were selected within the study. Good linearity and recovery values were obtained in the range of 50–3000 ng L −1 , and limits of detection of the method were within the range of 1.0–10.0 ng L −1 . Finally, the proposed method was successfully applied in sampling and analyzing volatile N -nitrosamines in a local smoking room, and the highest concentration of N -nitrosodimethylamine detected was 2954 ng L −1 . We suppose that the results may be meaningful for those suffering from second-hand smoke. [ABSTRACT FROM AUTHOR]

Carbon dots derived from citric acid and amines have been gaining considerable attention due to their high quantum efficiency, but there are researches proven the presence of small fluorescent molecules in those materials. In this work, with proper control of the synthetic conditions, highly fluorescent 5-oxo-3,5-dihydro-2H-thiazolo[3,2 -a ]pyridine-7-carboxylic acid (TPCA) as nice needle-like crystals were harvested by a simple one-step hydrothermal method directly based on the reaction of citric acid and cysteamine hydrochloride. The proposed synthesis route does not need extra complicated purification process. The yield of TPCA was 46.9% and the quantum yield was as high as 83.2%. Experimental results confirmed that TPCA possesses all advantages of carbon dots reported previously with similar starting materials. In addition, a novel and effective fluorescent probe, TPCA-Ag + , was designed for sensitive and selective sensing of dopamine (DA) based on in-situ formation of sliver nanoparticles. The calibration curve for DA was linear up to 0.4 μmol/L, and a detection limit of 0.75 nmol/L was attained. The method was successfully applied to the determination of DA in dopamine hydrochloride injection and urine samples and the standard addition recoveries were in a range of 87.2–102.8%. [ABSTRACT FROM AUTHOR]

The structural and magnetic properties of sol-gel-derived Mn-doped CeO2films were studied. The magnetic measurements show that the samples have room temperature ferromagnetism. The magnetization saturations were 0.75 μB/Mn, 0.93 μB/Mn and 1.12 μB/Mn for samples with 1%, 3% and 5% of Mn, respectively. The ferromagnetism of these samples is the intrinsic property. Since XRD results show the samples are single-phase of the pure CeO2structure, indicating that Mn doping does not form other structures and impurities. Raman scattering also confirm the absence of Mn-related oxide. As increasing the Mn content, the crystallite size decrease, but the ferromagnetism increases. [ABSTRACT FROM PUBLISHER]

The rapid development of fluorescent nanomaterials has broadened a new horizon for the design of easy-to-use and sensitive sensors. Herein, the stable, water-soluble and fluorescent L-Cystine modified copper nanoclusters (CuNCs) were prepared via size-focusing etching method. The maximum emission wavelength of the obtained CuNCs was 500 nm with an excitation wavelength of 396 nm. The as-prepared CuNCs can only emit faint light when dispersed in aqueous solution, but generate obvious fluorescence intensity enhancement after adding specific amount of 2,4,6-trinitrotoluene (TNT). Under the optimal conditions, the CuNCs were adopted as an effective fluorescence probe for the detection of trace TNT through fluorescence “turn-on” mode for the first time. The calibration curve of TNT was linear up to 4.8 μM, with a detection limit of 9.1 nM. [ABSTRACT FROM AUTHOR]

• Mn doped CeO 2 films were deposited on Si(100) substrates by magnetron sputtering. • Optical properties of Mn doped CeO 2 films are studied by spectroscopic ellipsometry. • Refractive index n and extinction coefficient k are functions of the Mn contents. • The optical band gap energies E g are functions of the Mn doped contents. • The values of n, k and E g increase linearly with increasing Mn doped content. Mn doped CeO 2 (Ce 1- x Mn x O 2 , x =0, 0.03, 0.06) thin films were deposited on Si (100) substrates by radio-frequency magnetron sputtering. X-ray diffraction and Raman analysis indicates that the films are cubic fluorite crystal structure with a preferred orientation along (111), which is the same as that of pure CeO 2. Atomic force microscopy reveals that the film surface morphology is dependent on the Mn doped content. The influence of Mn doped content on the optical properties was studied by spectroscopic ellipsometry (SE) in the UV-NIR region (210∼2500 nm). The energy dispersion optical constants (the refractive index n and the extinction coefficient k) of Ce 1- x Mn x O 2 thin films were obtained by analyzing the SE spectra. Under the assumption of a direct band-to-band transition, the optical band gap energies E g for these films were determined. The values of n, k and E g are functions of the Mn doped contents. The results showed that the E g values of the Ce 1- x Mn x O 2 thin films are 3.22, 3.32 and 3.35 eV, and the n values at wavelength of 632 nm are about 2.29, 2.38 and 2.49 for Mn doped content x =0, 0.03 and 0.06, respectively. The values of n and E g increases linearly with increasing Mn doped content. [ABSTRACT FROM AUTHOR]

Rapid development of nanomaterials has extended a new horizon for sensitive and easy-to-use sensors. Robust determination of nitro-explosives with nano-sensors has attracted great attentions due to the increasing safety concern. In this work, strongly fluorescent polyacrylamide coated CdTe(S) quantum dots (CdTe(S)@PAM QDs) with good dispersity and stability have been prepared by a facile, effective and reliable photochemical method through simple one-step UV irradiation. The prepared QDs were systematically characterized and the results proved that the prepared material could be readily used for the sensitive and selective sensing of 2,4,6-trinitrotoluene (TNT). The influence of experimental conditions on the analytical performance was investigated. With a QD concentration of 3.13 μmol/L, the calibration curve of TNT was linear up to 0.48 μmol/L, and a LOD (S/N = 3) of 2.1 nmol/L was attained. In combination of simple analyte extraction, no interference was observed from common inorganic ions and organic substances. TNT in samples with complicated matrices was successfully determined. The standard addition recoveries obtained from water and soil samples were in a range of 93.2–106.3%. [ABSTRACT FROM AUTHOR]

Undoped and Cu-doped ZnO (Zn 1 − x Cu x O: x = 0.00, 0.03, 0.06, 0.10) films were prepared on Si(100) substrates by the sol-gel method, and the effects of Cu content on the structural, and optical properties of these films were investigated by X-ray diffraction (XRD) and UV–visible spectroscopic ellipsometry (SE). XRD patterns revealed that all the films were monophasic and had wurtzite structure with (002) preferential orientation along c-axis, indicating there were not any secondary phases. The measured UV–visible SE spectra were analyzed with an appropriate procedure to accurately determine the thickness and the optical constants. We found that the refractive index and the extinction coefficient increase with Cu content increasing. The optical band gap ( E g ) has been calculated by classical Tauc formula, and the E g values decrease as Cu content increasing. The variation in E g with different Cu content revealed that the E g value was affected by doping Cu. These mean that we can control the optical properties of the ZnO films by varying Cu content, which might be important in view of designing integrated optic devices. [ABSTRACT FROM AUTHOR]

Graphs are widespread in many real-life practical applications. One of a graph’s fundamental and popular researches is investigating the relations between two given vertices. The relationship between nodes in the graph can be measured by the shortest distance. Moreover, the number of paths is also a popular metric to assess the relationship of different nodes. In many location-based services, users make decisions on the basis of both the two metrics. To address this problem, we propose a new hybrid-metric based on the number of paths with a distance constraint for road networks, which are special graphs. Based on it, a most relevant node query on road networks is identified. To handle this problem, we first propose a Shortest-Distance Constrained DFS, which uses the shortest distance to prune unqualified nodes. To further improve query efficiency, we present Batch Query DFS algorithm, which only needs only one DFS search. Our experiments on four real-life road networks demonstrate the performance of the proposed algorithms. [ABSTRACT FROM AUTHOR]

We present the optical and the structural properties of porous SiO2 films fabricated by using a glancing angle deposition technique. The influence of the glancing angle on the pseudorefractive index of porous SiO2 films was studied by spectroscopic ellipsometry in the UV-visible region. The relationships among the pseudorefractive index, the porosity, and the glancing angle are determined. The results show that the pseudorefractive index decreases and the porosity increases with the increase of glancing angle. The minimum pseudorefractive index is found to be 1.11 at 532 nm for the porous SiO2 film deposited at a glancing angle of 87°. The structural and surface morphology of these samples was also investigated by using a scanning electron microscope. The results indicate that the as-deposited SiO2 thin films are porous with a tilted-columnar structure and low pseudorefractive index. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We present the optical and the structural properties of porous SiO2 films fabricated by using a glancing angle deposition technique. The influence of the glancing angle on the pseudorefractive index of porous SiO2 films was studied by spectroscopic ellipsometry in the UV-visible region. The relationships among the pseudorefractive index, the porosity, and the glancing angle are determined. The results show that the pseudorefractive index decreases and the porosity increases with the increase of glancing angle. The minimum pseudorefractive index is found to be 1.11 at 532 nm for the porous SiO2 film deposited at a glancing angle of 87°. The structural and surface morphology of these samples was also investigated by using a scanning electron microscope. The results indicate that the as-deposited SiO2 thin films are porous with a tilted-columnar structure and low pseudorefractive index. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Pure BiFeO3thin films with different substrate temperatures (600°C and 650°C) were prepared using sputtering method on Pt /Ti /SiO2/Si(111) substrates. X-ray diffraction analysis reveals that no second phases existed and the structure changed with different substrate temperatures. According to the SEM results, the surface configuration of the BFO film was improved when sputtered at a lower temperature. The P-E curves show a well-shaped hysteresis loop for both BFO films. The spontaneous polarization of two films deposited at 600°C and 650°C is 56 μc/cm2and 72 μc/cm2respectively when measured at room temperature. [ABSTRACT FROM AUTHOR]

The transparent ZnO thin films were prepared on Si(100) substrates by the sol-gel method. The structural and optical properties of ZnO thin films, submitted to an annealing treatment in the 400-700°C ranges are studied by X-ray diffraction (XRD) and UV-visible spectroscopic ellipsometry (SE). XRD measurements show that all the films are crystallized in the hexagonal wurtzite phase and present a random orientation. Three prominent peaks, corresponding to the (100) phase (2 θ ≈ 31.8°), (002) phase (2 θ ≈ 34.5°), and (110) phase (2 θ ≈ 36.3°) appear on the diffractograms. The crystallite size increases with increasing annealing temperature. These modifications influence the optical properties. The optical constants and thickness of the films have been determined by analysing the SE spectra. The optical bandgap has been determined from the extinction coefficient. We found that the refractive index and the extinction coefficient increase with increasing annealing temperature. The optical bandgap energy decreases with increasing annealing temperature. These mean that the optical quality of ZnO films is improved by annealing. [ABSTRACT FROM AUTHOR]

[Display omitted] • Chlorophyll-based fluorescent material was extracted from willow seeds. • The C-WS can retain perfect red fluorescence performance in aqueous solution. • An "on-off-on" sensing system was constructed for Cu2+ and biothiols detection. • The C-WS was applied for the visualization of intracellular Cu2+ and biothiols. The environmental risk of artificial synthetic dyes sparked interest in exploring high-security fluorescent materials for suitable analysis applications. Chlorophyll-based fluorescent material is a good candidate but subjects to inferior dispersibility and low fluorescence efficiency in water. In this work, we successfully prepared a water-dispersible chlorophyll-based fluorescent material through simple solvent extraction of willow seeds. Compared to other conventional sources of chlorophyll, such as willow leaves, metasequoia, and green algae, only the chlorophyll-based material from willow seeds (C-WS) can retain good near-infrared fluorescence performance with an emission wavelength of 677 nm in the water phase, which can promote the practical application of chlorophyll-based fluorescent materials. An "on-off-on" sensing system was constructed based on C-WS for the highly sensitive and selective detection of Cu2+ and biothiols in aqueous solution. The limit of detection for Cu2+ and GSH can reach 1.2 nM and 92 nM, respectively. Furthermore, the proposed system was successfully used in the detection of Cu2+ in real water samples and biothiols in food samples, and successfully applied for the visualization of intracellular Cu2+ and biothiols in Hela cells. [ABSTRACT FROM AUTHOR]

We previously reported that neutrophil elastase (NE) downregulates transforming growth factor- β (TGF-β)-maintained tropoelastin mRNA levels in lung fibroblasts through transactivation of the epidermal growth factor (EGF) receptor (EGFR)/Mek/Erk pathway, which is dependent on the NE-initiated release of soluble EGFR ligands. In the present study, we investigated the mechanism by which EGF downregulates tropoelastin expression. We found that EGF downregulates tropoelastin expression through inhibition of TGF-β signaling. We show that EGF does not prevent the TGF-β-induced nuclear accumulation of Smad2/3; rather, EGF stabilizes the short-lived Smad transcriptional corepressor TG-interacting factor (TGIF) via EGFR/Mek/Erk-mediated phosphorylation of TGIF. Elevation of TGIF levels, either by TGIF overexpression or prevention of TGIF degradation, is sufficient to inhibit TGF-β- induced tropoelastin expression. Moreover, TOIF is essential for EGF-mediated downregulation of tropoelastin expression, inasmuch as small interfering RNA knockdown of TGIF blocked EGF-induced downregulation of tropoelastin. Finally, we demonstrated that NE treatment, which releases EGF-Iike growth factors, causes stabiliza- tion of TOIF through the EGFR/Mek/Erk pathway. These results suggest that EGFR/Mek/Erk signaling specifically antagonizes the proelastogenic action of TGF-β in lung fibroblasts by stabilizing the Smad transcriptional corepressor TGIF. [ABSTRACT FROM AUTHOR]

Abstract: Apparent Re–Os ages of some magmatic sulfide ore deposits are older than the zircon and baddeleyite U–Pb ages which are interpreted as the formation age of the host intrusions. The Jinchuan Ni–Cu–PGE deposit of China, the world''s third largest, is such a case. We report apparent Re–Os isochron ages of 1117±67 Ma, 1074±120 Ma and 867±75 Ma with initial 187Os/188Os ratios of 0.120±0.012, 0.162±0.017 and 0.235±0.027 for disseminated ores, sulfides from the disseminated ores and massive ores from Jinchuan, respectively. Using these data and Re–Os ages from the literature, we find that the oldest apparent Re–Os age and lowest initial Os isotope ratio are from disseminated ores which contain small amounts of sulfide minerals, the highest initial Os isotope ratios and youngest apparent Re–Os ages, consistent with the zircon and baddeleyite U–Pb ages, are from massive ores containing 90–100 modal% sulfide, and net-textured ores with about 25 modal% sulfides yield apparent Re–Os ages and initial Os ratios intermediate between those of the disseminated and massive ores. Because Os diffusion between sulfides is inhibited by the intervening silicates even at high temperatures, re-equilibration did not occur in the disseminated ore and the samples retained the Os ratios of the contaminated magma, leading to geologically meaningless ages that are older than the formation age of the rocks. While Os-bearing sulfide minerals and magnetite show low closure temperatures of Os diffusion and the sulfide minerals in the massive ore are closely connected with each other, facilitating fast diffusion of Os, re-equilibration of Os was achieved during cooling of the ore from about 850 °C after the segregation to about 400 °C. Thus, an age corresponding to the formation time and an elevated initial Os ratio were yielded by the massive ore. Os isotopes in the net-textured ore behave in the way intermediate between the disseminated and massive ores. Pb isotope data support the Os results. Disseminated ores have heterogeneous Pb isotope ratios whereas Pb in the massive ores is more uniform, consistent with Pb isotopic equilibration in the massive ores, but not in the disseminated ores. [Copyright &y& Elsevier]

Abstract: The existence and the size of large methane van der Waals clusters (CH4) N , have been characterized for the first time. (CH4) N van der Waals clusters were generated by the supersonic expansion of a gaseous mixture consisting of 90% H2 and 10% CH4 at nozzle temperatures of −30 and 27°C. Based on the buffer gas induced beam-broadening technique, the average sizes of (CH4) N clusters were determined for all values of expansion at different stagnation pressures. For an identical stagnation pressure, the (CH4) N cluster size produced by expansion at a nozzle temperature of −30°C were larger than these produced by expansion at nozzle temperature of 27°C, and cluster sizes of 120 molecules and 60 molecules have been measured for 10bar stagnation pressure, respectively. In addition, we found (CH4) N cluster formation did not occur by supersonic expansion of pure CH4 gas at nozzle temperature of 27°C. These results reveal that the presence of H2 permits the evacuation of the heat of condensation and, thus promotes the (CH4) N cluster nucleation. [Copyright &y& Elsevier]

Abstract: Stoichiometric Pb(Zr x Ti(1−x)O3) (PZT) thin films deposited on Si(100) substrates have been prepared by the sol–gel technique. Two sets of films of amorphous and polycrystalline, containing 20%, 30%, 50%, and 60% Ti, were prepared and investigated. The microstructures and surface morphologies of the films have been studied by X-ray diffraction and atomic force microscopy. The optical properties were studied by spectroscopic ellipsometry (SE) in the UV–visible region. Using a four-phase fitting model, the refractive index n and extinction coefficient k was obtained by analyzing the SE spectra. The optical band gap energies E g for these films were determined under the assumption of a direct band-to-band transition. The results show that the refractive index, extinction coefficient, and band gap energy of the films show a systematic variation with compositions and microstructures. The optical band gap energy of the amorphous PZT films shift to high energy is mainly due to the quantum-size effect. [Copyright &y& Elsevier]

Size distributions through large van der Waals cluster beam cross-section are studied with the pick-up technique. Based on our experimental results, we observed that the larger cluster is always concentrated in the center of the beam. From the center to the periphery, the cluster size gradually decreases. The size distributions through the beam cross-section depend on incoming cluster size and incoming cluster velocity. The larger the incoming cluster size or the faster the incoming cluster velocity, the flatter the size distributions through the beam cross-section are found. These experimental results are interpreted by the Mack focusing effect. [Copyright &y& Elsevier]

• Enhancement of fluorescence of CDs was realized via organic acid participation. • Colorimetric and fluorescent sensor for Cu2+ detection was constructed. • Successful detection of Cu2+ in water and urine samples was performed. • The feasibility of biological application was evaluated by cell experiment. In-depth research on surface functionalization of carbon dots (CDs) has opened new horizons for their application in chemosensing and biosensing. However, the practicability of CDs is still limited due to their unmanageable fluorescence properties. In this study, organic acid was employed to regulate and control the fluorescence performance of CDs. A remarkable enhancement of fluorescence and redshift of the fluorescent band of CDs was observed via organic acids' participation in the water phase preparation process. Furthermore, a colorimetric and fluorescent dual-readout strategy was constructed for the analysis of copper ions (Cu2+) based on ethylenediaminetetraacetic acid (EDTA)-regulated carbon dots. The proposed sensing system can be used in the fast detection of Cu2+ via an obvious solution color change from yellow to brown under natural light, and the trace analysis of Cu2+ can be realized by quenching the green fluorescence band with detection limit of 21 nM. The designed sensor has been employed to the analysis of Cu2+ in water and urine samples successfully, and cell imaging experiment was performed to evaluate the feasibility of biomedical applications. [ABSTRACT FROM AUTHOR]

For decades, researches have been involving in improving and optimizing solid-phase microextraction (SPME) technique to fit the growing environmental analysis demand. But it is more significant now to introduce meaningful information into the analysis line instead of improving every step in SPME. Herein, we design a carbon dots (CDs) based SPME platform and report its unique application in selective early screening and sensitive detection of 2-nitroaniline. The fluorescence quenching state of the CDs fiber after extraction could be used to prejudge whether an environmental sample contains 2-nitroaniline exceeding the maximum permitted level (30 μg L−1) regulated by the Chinese Ministry of Environmental Protection or not. Photo-induced electron transfer (PET) is believed to be the primary quenching route that leads to electron transfer from the electron-rich CDs to the electron-deficient analyte. A preliminary in vivo study on Daphnia magna and a 2-nitroaniline assay in environmental water and biofluid samples suggested the safety and the excellent qualitative ability of the proposed platform. As a result, the innovative incorporation of fluorescence sensing and SPME not only achieves the information imbedding of environmental analysis system, but also combines the advantages of two techniques including early visual-screening, reusability (≥50 times), high specificity and excellent quantitative ability (detection limit: 0.011 μg L−1). We believe this study can open new avenues in the field of environmental toxicant monitoring. Image 1 • A carbon dots (CDs) based solid-phase microextraction (SPME) platform was designed. • Nitroaniline's concentration level could be prejudged by the device's fluorescence. • The quenching point of the CDs fiber could be tuned as needed. • 2-Nitroaniline in urine/environmental samples was visual-screened and quantified by GC-MS. [ABSTRACT FROM AUTHOR]

Sulfur isotope measurements in three sulfide (two pyrite and one pyrrhotite) samples on two epoxy mounts showed that the mount‐to‐mount variation of raw δ34S values was negligible when secondary ion mass spectrometry (SIMS) analytical settings remained stable. In consequence, an off‐mount calibration procedure for SIMS sulfur isotope analysis was applied in this study. YP136 is a pyrrhotite sample collected from northern Finland. Examination of thin sections with a polarising microscope, backscattered electron image analyses and wavelength dispersive spectrometry mapping showed that the sample grains display no internal growth or other zoning. A total of 318 sulfur isotope (spot) measurements conducted on more than 100 randomly selected grains yielded highly consistent sulfur isotope ratios. The repeatability of all the analytical results of 34S/32S was 0.3‰ (2s, n = 318), which is the same as that of the well‐characterised pyrite reference materials PPP‐1 and UWPy‐1. Its δ34S value determined by gas mass spectrometry was 1.5 ± 0.1‰ (2s, n = 11), which agrees with the SIMS data (1.5 ± 0.3‰, 2s) calibrated by pyrrhotite reference material Po‐10. Therefore, YP136 pyrrhotite is considered a candidate reference material for in situ sulfur isotope determination. Key Points: Off‐mount calibration is applicable to SIMS pyrite and pyrrhotite sulfur isotope analyses.YP136 is a new potential pyrrhotite reference material suitable for calibrating sulfur isotope determination by SIMS.SIMS δ34S value = 1.5 ± 0.3‰ (2s) [ABSTRACT FROM AUTHOR]

Manual methods to detect and identify potential ground collapse hazards have a high volume of workload and rely on manual skills and experience strongly, with substantial inconsistencies. This paper proposes an automatic recognition method of potential underground hazards and designs an object detection-based algorithm to predict the hidden danger of ground collapse, called GCNet. The GCNet is a ground collapse hazard detection network, which is developed to detect underground hazards, including cavities, poor soil quality, pipelines, and soil background. The GCNet uses the deep residual network ResNet101 and feature pyramid network (FPN) to extract features and a task coordination network (TCN) to identify the category and location of hidden underground hazards. Further, a feature enhancement method based on the regional binary pattern is proposed to improve the accuracy of the proposed model by expanding the ground-penetrating radar (GPR) data by adding multi-level features to GPR images. The experiments are conducted on a large amount of real GPR data and experiment results show that the proposed automatic recognition method can surpass the existing deep learning-based methods in hidden underground hazard recognition and identification. [ABSTRACT FROM AUTHOR]

Amorphous Cu(II)-cyanoimidazole frameworks were designed and served as peroxidase mimics for H 2 S detection. [Display omitted] Metal-organic frameworks with hierarchical porosities and exposed active sites are promising for ideal enzyme mimics. In this work, we developed a simple and feasible air oxidation strategy to prepare amorphous Cu(II)-cyanoimidazole frameworks (aCu(II)-CIFs) using CuI as the metal source in dimethylsulfoxide. Benefiting from coordination unsaturation and hierarchical porosities, aCu(II)-CIFs exhibit inherent peroxidase-mimic activity for rapid colorimetric reaction of 3,3′,5,5′-tetramethylbenzidine (TMB). aCu(II)-CIFs were utilized to develop a colorimetric platform for specific H 2 S assay in the range of 0.6–30 μM, achieving a limit of detection (LOD) of 0.071 μM. Structural collapse of aCu(II)-CIFs and subsequent generation of stable CuS particles, along with reducibility of H 2 S, are likely responsible for suppressing TMB ox conversion. The proposed method successfully detected H 2 S in real water samples, with a relative standard deviation (RSD) lower than 8.4%. This contribution is expected to offer unique insights into the amorphization mechanisms of MOFs and their potential applications. [ABSTRACT FROM AUTHOR]

[Display omitted] Carbon dots (CDs) provides unprecedented opportunities for optical applications due its unique properties, but the energy-extensive consumption, high-risk factor and time-consuming synthesis procedure greatly hinders its industrialization process. Herein, we proposed an ultra-low energy consumption solvent-free synthetic strategy for fast preparing green/red fluorescence carbon dots (G-/R-CDs) using m-/o-phenylenediamine and primary amine hydrochloride. The involvement of primary amine hydrochloride can improve the formation rate of G-CDs/R-CDs through effectively absorbing microwave energy and providing acid react environment. The developed CDs exhibit good fluorescence efficiency, optical stability and membrane permeability for dexterous bioimaging in vivo. Based on inherently high nitrogen content, the G-CDs/R-CDs possess excellent nuclear/nucleolus targeting ability, and were successfully applied for screening cancer and normal cells. Furthermore, the G-CDs/R-CDs were further applied for fabricating high-safety and high-color rendering index white light-emitting diodes, providing a perfect candidate for indoor lighting. This study opens up new horizons for advancing practical applications of CDs in related fields of biology and optics. [ABSTRACT FROM AUTHOR]

Pure BiFeO 3 (BFO), Nd doped BiFeO 3 (Bi 0.9 Nd 0.1 FeO 3 , hereafter BNFO) and Nd–Co codoped BiFeO 3 (Bi 0.9 Nd 0.1 Fe 0.9 Co 0.1 O 3 , hereafter BNFCO) films on Si(100) were prepared by a sol–gel method. X-ray diffraction shows that all the films were single perovskite structure and a phase transition appeared in BNFO and BNFCO films. Dense microstructure with evenly distributed grains about 100 nm was observed by SEM. The ellipsometric measurements were carried out in the UV–visible region and the corresponding experimental data were fitted by using a model consisting of air/roughness/film/Si(100). At a wavelength of 600 nm, the refractive indexes of 2.69, 2.84 and 2.78 were estimated for the BFO, BNFO and BNFCO films, respectively. The extinction coefficients of these films were almost zero at wavelengths larger than 550 nm. The band gaps of the BFO, BNFO and BNFCO films were estimated to be 2.95, 2.89 and 2.93 eV, respectively. [ABSTRACT FROM AUTHOR]

Green, economical and effective method was developed for synthesis of fluorescent carbon dots (CDs), using one-pot hydrothermal treatment of Lycii Fructus. Optical and structural properties of the CDs have been extensively studied by UV–visible and fluorescence spectroscopic, x-ray diffraction (XRD) techniques, transmission electron microscopy (TEM) and high resolution TEM (HRTEM). Surface functionality and composition of CDs has been illustrated by Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS) spectra and elemental analysis. The fabricated CDs possess stable fluorescent properties. The fluorescent quantum yield of the CDs can reach 17.2%. The prepared CDs emitted a broad fluorescence between 415 and 545 nm and their fluorescence was tuned by changing excitation wavelength. Meanwhile, the fluorescence intensity of the CDs could be significantly quenched by Fe 3 + (turn-off). The CDs exhibit captivating sensitivity and selectivity toward Fe 3 + with a linear range from 0 to 30 μM and a detection limit of 21 nM. The prepared CDs were successfully applied to the determination of Fe 3 + in the urine samples, the water samples from the from the Yellow River and living HeLa (Henrietta Lacks) cells. Moreover, the low-toxicity and excellent biocompatibility of the CDs were evaluated through MTT assay on HeLa cells. The CDs were also employed as fluorescent probes for multicolor imaging of HeLa cells successfully. [ABSTRACT FROM AUTHOR]

Self-assembling of rhodanine (R) on gold nanoparticles was used to construct a colorimetric sensor for detecting Hg 2+ in aqueous media. Gold nanoparticles capped with R (AuNPs@R) were well dispersed in phosphate buffer (NaH 2 PO 4 -Na 2 HPO 4 ) as clear wine red solutions. The presence of Hg 2+ induced aggregation of AuNPs@R and resulted in a color change from wine red to blue. The experimental results indicated that formation of rhodanine-Hg 2+ -rhodanine (R-Hg 2+ -R) structure was the initial driving force of the aggregation, without the use of expensive DNA and complicated functionalization of AuNPs. This aggregation phenomenon is similar to that used for the determination of Hg 2+ by thymine. The color change was successfully used for the determination of Hg 2+ . Under the optimum conditions, the linear relationship between the absorbance ratio A 650 /A 520 and Hg 2+ concentration was in a range of 0.02–0.5 μM, and the limit of the detection (LOD) was 6.0 nM. The color change was evident and it is possible to recognize the presence of Hg 2+ as low as 0.1 μM by the naked eye. The method avoids complicated surface modifications and tedious separation processes. Its applicability was verified by analysis of Hg 2+ in tap water and lake water with the quantitative spike recoveries ranging from 94.8 to 110%. [ABSTRACT FROM AUTHOR]

The video moment retrieval task aims to fetch a target moment in an untrimmed video, which best matches the semantics of a sentence query. Existing methods mainly focus on utilizing two separate modules: one learns intra-modal relations to understand video and query contents, and the other explores inter-modal interactions to build a semantic bridge between video and language. However, intra-modal relations information can be easily overlooked when capturing inter-modal interactions. In fact, intra-modal relations and inter-modal interactions can be learned simultaneously within a unified module to make video and sentence guide each other. Towards this end, we propose a Cross-Modal Interaction Network (CMIN) for video moment retrieval by jointly exploring the intra-modal relations and inter-modal interactions between video frames and query words. In CMIN, a query-guided channel attention module is designed to suppress query-irrelevant visual features and enhance crucial contents; then a cross-attention module simultaneously considers intra-modal relations within each modality and fine-grained inter-modal interactions between frames and words, to enhance the semantic relevance between video and sentence query. Compared to the state-of-the-art methods, the experiments on two public datasets (Charades-STA and TACoS) demonstrate the superiority of our method. [ABSTRACT FROM AUTHOR]

Semiconductive photocatalytic materials have received increasing attention recently due to their ability to transform solar energy into chemical fuels and photodegrade a wide range of pollutants. Among them, cadmium sulfide (CdS) nanoparticles have been extensively studied as semiconductive photocatalysts in previous studies on hydrogen generation and environmental purification due to their suitable bandgap and sensitive light response. However, the practical applications of CdS are limited by its low charge separation, which is caused by its weak ability to separate photo-generated electron-hole pairs. In order to enhance the photoelectrochemical activity of CdS, a polymer based on viologen (PHV) was utilized to create a series of PHV/CdS hybrid films so that the viologen unit could work as the electron acceptor to increase the charge separation. In this work, various electrochemical, spectroscopic, and microscopic methods were utilized to analyze the hybrid films, and the results indicated that introducing PHV can significantly improve the performance of CdS. The photoelectrochemical activities of the hybrid films were also evaluated at various ratios, and it was discovered that a PHV-to-CdS ratio of 2:1 was the ideal ratio for the hybrid films. In comparison with CdS nanoparticles, the PHV/CdS hybrid film has a relatively lower band gap, and it can inhibit the recombination of electrons and holes, enhancing its photoelectrochemical activities. All of these merits make the PHV/CdS hybrid film as a strong candidate for photocatalysis applications in the future. [ABSTRACT FROM AUTHOR]

Nickel contents of olivine have been widely used as petrogenetic indicators and as fertility indicators for magmatic sulfide potential of mafic-ultramafic intrusions, on the assumption that olivines crystallized from magmas that had equilibrated with sulfide liquid should be relatively depleted in Ni compared with a sulfide-free baseline. This has given rise to a large accumulation of data that is brought together here, along with data on volcanic olivines, to critically evaluate the effectiveness of the approach. We identify multiple sources of variance in Ni content of olivine at a given Fo content, including variability in mantle melt composition due to depth, water content (and possibly source), subsequent fractional crystallization with and without sulfide, recharge and magma mixing, batch equilibration between olivine and sulfide at variable silicate-sulfide ratio (R), and olivine/liquid ratio; and subsequent equilibration during trapped liquid crystallization in orthocumulates. Baselines for Ni in olivine in relation to Fo content are somewhat lower in orogenic belt settings relative to intrusions in continental large igneous provinces (LIPs). This is probably related to differences in initial parent magma compositions, with plume magmas generally forming deeper and at higher temperatures. No clear, universal discrimination is evident in Ni in olivine between ore-bearing, weakly mineralized, and barren intrusions, even when tectonic setting is taken into account. However, sulfide-related signals can be identified at the intrusion scale in many cases. Low-R factor and low-tenor sulfides are associated with low-Ni olivines in several examples, and these cases stand out clearly. Anomalously high-Ni olivines are a feature of some mineralized intrusions, in part due to trapped liquid reaction effects. However, in some cases, this mechanism cannot account for the magnitude of enrichment. In these cases, enrichment may be due to re-entrainment of "primitive" Ni-rich sulfide by a more evolved Fe-rich magma, driving the olivine to become Ni-enriched due to Fe-Ni exchange reaction between sulfide and olivine during transport. An extreme case of this process may account for ultra-Ni enriched olivine at Kevitsa (Finland), but more subtle signals elsewhere could be positive indicators. A lack of clear mineralized/barren distinction in specific groups of related intrusions, e.g., the deposits of NW China or the Kotalahti Belt in Finland, may well be due to "false negatives" where undiscovered mineralization exists in specific intrusions or in their feeder systems, or may also be due to a multiplicity of confounding factors. Wide variability of both Fo and Ni between related intrusions at regional scale may be a useful regional prospectivity indicator, more than an intrusion-scale discriminant, and is certainly informative as a petrogenetic indicator. In general, the use of Ni-olivine as a fertility tool is more likely to generate false negatives than false positives, but both are possible, and the technique should be used as part of a broader weight-of-evidence approach. [ABSTRACT FROM AUTHOR]

BiFe1-xCoxO3(x = 0, 0.05, 0.10, 0.15, 0.20, and 0.25) nanoparticles were prepared by a sol–gel method. A single-phase perovskite structure was formed in the pure BiFeO3particles. The secondary phase of Bi25FeO40was observed in Co doped samples and the phases of CoFe2O4were observed in BiFe0.8Co0.2O3and BiFe0.75Co0.25O3. The average crystal size of pure BiFeO3is about 84 nm and that was reduced from 84 nm to 49.7 nm with increasing Co content. Optical band gaps of BFCO nanoparticles decrease with the increase of Co concentration. The enhancement of room-temperature ferromagnetism was obtained in the Co doped BiFeO3particles. [ABSTRACT FROM PUBLISHER]

Plastic microchips can significantly reduce the fabrication cost but the adsorption of some analytes limits their application. In this work, background electrolyte containing ionic polymer and high content of organic solvent was adopted to eliminate the analyte adsorption and achieve highly efficient separation in microchip electrophoresis. Two dyes, rhodamine 6G (Rh6G) and rhodamine B (RhB) were used as the model analytes. By using methanol as the organic solvent and polyacrylic acid (PAA) as a multifunctional additive, successful separation of the two dyes within 75 μm id. microchannels was realized. The role of PAA is multiple, including viscosity regulator, selectivity modifier and active additive for counteracting analyte adsorption on the microchannel surface. The number of theoretical plate of 7.0 × 10 5 /m was attained within an effective separation distance of 2 cm using background electrolyte consisting 80% methanol, 0.36% PAA and 30 mmol/L phosphate at pH 5.0. Under optimized conditions, relative standard deviations of Rh6G and RhB detection (n = 5) were no more than 1.5% for migration time and 2.0% for peak area, respectively. The limit of detection (S/N = 3) was 0.1 nmol/L for Rh6G. The proposed technique was applied in the determination of both Rh6G and RhB in chilli powder and lipstick samples with satisfactory recoveries of 81.3–103.7%. [ABSTRACT FROM AUTHOR]

Pure BiFeO 3 and Gd, Mn doped BiFeO 3 particles were synthesized with a hydrothermal method in a reaction solution containing a mineralizer of KOH. The products were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, Raman spectroscopy, physical property measurement system and ferroelectric test system. Rietveld refinement and Raman spectra results reflect that the Gd, Mn doped samples undergo compositional-driven phase transition from rhombohedral to orthorhombic. Selected area electron diffraction and high-resolution transmission electron microscopy confirm the single-crystalline nature of our as-prepared samples. Compared with the linear magnetization-magnetic field relation in pure BiFeO 3 particles, a clear hysteresis M–H loop can be observed in the Bi 0.9 Gd 0.1 FeO 3 sample, which is ascribed to distorted spin cycloid and the magnetically active characteristic of Gd 3+ . Enhanced ferroelectric properties and reduced leakage current density were obtained in BiFe 0.9 Mn 0.1 O 3 and Bi 0.9 Gd 0.1 Fe 0.9 Mn 0.1 O 3 . The leakage current density of the BiFe 0.9 Mn 0.1 O 3 and Bi 0.9 Gd 0.1 Fe 0.9 Mn 0.1 O 3 was reduced by two orders of magnitude as compared to that of pure BiFeO 3 . [ABSTRACT FROM AUTHOR]

Bi1-xYxFe1-yMnyO3(BYFMO, x = 0, 0.1; y = 0, 0.05, 0.1, 0.15, 0.2, 0.25) particles were prepared via a sol-gel technique. The structural, morphological, optical, and ferromagnetic properties of the as-prepared BYFMO samples were analyzed. The crystal structures of all samples except Bi0.9Y0.1FeO3(contain a small amount of Bi25FeO40) were single-phase and crystallize in a rhombohedral structure (space group, R-3c). All 13 active modes were observed in the Raman spectra of pure BFO, which further confirmed its rhombohedral structure. Ferromagnetic properties and enhanced magnetic were observed inBi0.9Y0.1Fe0.9Mn0.1O3particlesand other Y-Mn co-doped particles, respectively. [ABSTRACT FROM AUTHOR]

Bi 0.9 Gd 0.1 Fe 0.9 Co 0.1 O 3 (BGFCO) films with thickness increasing from 318 to 877 nm were successfully deposited on Pt(111)/Ti/SiO 2 /Si(100) substrates by radio frequency magnetron sputtering. X-ray diffraction patterns demonstrated that all BGFCO films had a single perovskite-type structure with highly (012) and (024) preferred orientations regardless of the film thickness. The crystalline quality of the film was also improved with increase in film thickness. The grain sizes of BGFCO films using scanning electron microscopy analysis were monotonously increase with thickness. The ferroelectric and magnetic tests indicated that the film thickness of about 310–450 nm was an optimum thickness in our case where both the ferroelectric and ferromagnetic properties exhibit significant values consistent with the requirements for multiferroic material applications. The ferromagnetic behavior was enhanced for BGFCO film at 10 K compared to that of 300 K. The bifurcation of the field cooling and zero-field cooling magnetizations of BGFCO film in the whole temperature range from 5 to 300 K indicated the typical characteristic of a spin-glass-like behavior originating from domain wall pinning effects. The mechanisms for the effect of thickness variation on ferroelectric and ferromagnetic characteristics of BGFCO films were discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Solid-phase synthesis strategy was proposed for fabricating versatile Cu-CDNEs. • The Cu-CDNEs possess excellent fluorescent property and peroxidase-like activity. • A multi-mode specific detection platform for H 2 S was established based on Cu-CDNEs. • The developed Cu-CDNEs demonstrated broad-spectrum antibacterial capacity. The emergence of carbon dots-based nanozymes (CDNEs) has opened a broad horizon for multi-mode analysis and safety antibacterial application. However, the practical applications of CDNEs are currently hindered by unsatisfactory performance and complicated synthetic methodology. In this study, we developed a novel copper-doped CDNEs (Cu-CDNEs) with both excellent fluorescence property and peroxidase-like activity. The Cu-CDNEs can be synthesized easily by pyrolyzing a solid mixture of copper glutamate and ethylenediamine hydrochloride for 5 min. By investigating the inhibition of H 2 S on the peroxidase-like activity of Cu-CDNEs and the competitive interaction between H 2 S and 3,3′,5,5′-tetramethylbenzidine with reactive oxygen species, we established a dual-mode analysis system for colorimetric and fluorescent detection of H 2 S with the limit of detection of 20 nM and 25 nM, respectively. Furthermore, a convenient scanometric analysis mode also was developed and successfully applied for the accurate determination of H 2 S in actual water samples with recoveries of 96.8 %–107.7 %. Moreover, the designed Cu-CDNEs show good cytocompatibility from MTT results, and demonstrated broad-spectrum antibacterial capacity against Gram-positive/negative bacteria due to the surface positive charge and peroxidase-like activity. This study may provide valuable insights for rational design and broad applications in environmental and biomedical fields using functional nanozymes. [ABSTRACT FROM AUTHOR]

FeSe microparticles coated by ultrathin nitrogen-doped carbon (FeSe@NC) have been synthesized through the dopamine coating of FeOOH precursor and the post-calcination treatment. The strong interfacial interaction between FeSe and NC guarantees FeSe@NC with fast electron/Na+ transport kinetics and outstanding structural stability. [Display omitted] • FeSe@NC exhibits preeminent performance as an anode for sodium-ion batteries. • Analyses of ex-situ XRD, ex-situ TEM and DFT calculations reveal that the electrochemical mechanism in FeSe. • Excellent performance is related to a reversible phase transformation from hexagonal to tetragonal. • NVPF@rGO//FeSe@NC full battery maintains a capacity of 241 mAh/g after 2000 cycles at 1 A/g. Transition metal selenides have gained enormous interest as anodes for sodium ion batteries (SIBs). Nonetheless, their large volume expansion causing poor rate and inferior cycle stability during Na+ insertion/extraction process hinders their further applications in SIBs. Herein, a confined-regulated interfacial engineering strategy towards the synthesis of FeSe microparticles coated by ultrathin nitrogen-doped carbon (NC) is demonstrated (FeSe@NC). The strong interfacial interaction between FeSe and NC endows FeSe@NC with fast electron/Na+ transport kinetics and outstanding structural stability, delivering unexceptionable rate capability (364 mAh/g at 10 A/g) and preeminent cycling durability (capacity retention of 100 % at 1 A/g over 1000 cycles). Furthermore, various ex situ characterization techniques and density functional theory (DFT) calculations have been applied to demonstrate the Na+ storage mechanism of FeSe@NC. The assembled Na 3 V 2 (PO 4) 2 F 3 @rGO//FeSe@NC full cell also displays a high capacity of 241 mAh/g at 1 A/g with the capacity retention of nearly 100 % over 2000 cycles, and delivers a supreme energy density of 135 Wh kg−1 and a topmost power density of 495 W kg−1, manifesting the latent applications of FeSe@NC in the fast charging SIBs. [ABSTRACT FROM AUTHOR]

[Display omitted] • The selective assembly of BiOI dielectric layers effectively enhances the remanent depolarization field of the Bi 4 NbO 8 Cl. • The advantage of side-by-side composite structure for charge transfer is demonstrated by theoretical analysis. • The construction of the surface selective dielectric layer increases the residual depolarization field from 1.45 to 2.34 V. • The enhanced residual depolarization field effectively promotes the charge separation, resulting in a 7.35-fold increase in the photodegradation efficiency of Bisphenol A. Spontaneous polarization induced by the unique crystal structure of ferroelectric semiconductor photocatalyst facilitates charge separation and injects new vitality into the improvement of the photocatalytic activity. However, due to the complexity of multi-electric field coupling, the actual efficiency of charge separation driven by the depolarization field is restricted by the shielding field, which is lower than theoretical expectations. Here, we take Bi 4 NbO 8 Cl as a model system and selectively construct a BiOI dielectric layer on its positive polarized surface through the adsorption-self-assembly method, aiming to reduce the attenuation of the shielding field to the depolarization field. The enhanced residual depolarization field (RDF) is quantitatively characterized by ferroelectric performance test. Moreover, the charge transfer path and final position are elaborated by photo-deposition experiments, while high-quality interface and calculated difference of the potential between Bi 4 NbO 8 Cl and BiOI is responsible for the formation of charge transfer channel. The enhanced RDF promotes the separation of charges, which causes that Bi 4 NbO 8 Cl/BiOI photo-degradation of bisphenol A (BPA) gives 7.35-fold greater efficiency than Bi 4 NbO 8 Cl. This scheme of weakening the shielding field by surface reconstruction engineering is promising to be extended to more ferroelectric photocatalyst systems. [ABSTRACT FROM AUTHOR]

BiFeO3(BFO) and Bi0.9Pr0.1Fe1-xNixO3(0.01 ≤ x ≤ 0.1) thin films have been fabricated on Pt(111)/Ti/SiO2/Si substrates by a sol-gel method. The Pr and Ni co-substitution effects on the structural and ferroelectric properties of BFO films were investigated by X-ray diffraction (XRD), Raman spectroscopy and ferroelectric measurements. XRD and Raman analysis demonstrated that all films have a pure phase related to perovskite-type structure. The ferroelectric test indicated that the ferroelectric properties of BFO films were improved with Pr and Ni co-doping. The remnant polarization of Bi0.9Pr0.1Fe0.95Ni0.05O3film was 70 μC/cm2. The leakage current density-applied electric field behavior measurement showed that Pr and Ni co-substitution was effective to reduce the leakage current density of BFO thin films. [ABSTRACT FROM AUTHOR]

A cascade colorimetric detection of salivary D-amino acids (DAAs) holds promise for the preliminary screening diagnosis of gastric cancer. Pursuing metal-organic complexes with high peroxidase-mimic (POD-mimic) activity is crucial to enhance diagnosis efficiency. In this work, we developed a straightforward strategy in a "one-pot" process to modulate the POD-mimic activity of CuX-trithiocyanuric acid (CuX-TTCA) complexes. By adjusting the molar ratios of CuX (Cl, Br, and I) and TTCA during synthesis to modify the coordination configuration of Cu(I) in CuX-TTCA, we easily tuned their POD-mimic activities. Among them, CuCl-TTCA-2 with a feeding molar ratio of 2:1 for CuCl:TTCA exhibited remarkable POD-mimic activity attributed to its exposed catalytic active sites and efficient mass transfer ability during catalysis. Long-lived 1O 2 was identified as the primary reactive oxygen intermediate. A highly sensitive and selective cascade colorimetric detection platform was developed for two typical DAAs associated with gastric cancer, namely D-proline and D-alanine, achieving limit of detection values of 1.1 and 0.8 μM, respectively. As a proof-of-concept application, our cascade detection platform demonstrated excellent specificity in distinguishing saliva samples between gastric cancer patients and healthy individuals. The outstanding selectivity and reliable outcomes from DAAs assay make our detection platform highly promising for preliminary screening diagnosis of gastric cancer and patient self-detection applications. Our straightforward strategy for tuning POD-mimic activity provides an in-depth understanding on structure-activity relationship in nanozymes, offering valuable opportunities to advance enzyme-mimic optimization for other potential applications. [Display omitted] • A "one-pot" process to modulate peroxidase-mimic activity of CuX-trithiocyanuric acid complexes. • The peroxidase-mimic activity were tuned by modifying the coordination configuration of Cu(I) sites. • Long-lived 1O 2 was identified as the primary reactive oxygen intermediate. • A cascade colorimetric detection platform for salivary D-amino acids was developed. • The detection platform exhibited promising for preliminary screening diagnosis of gastric cancer. [ABSTRACT FROM AUTHOR]

Abstract: The ~260Ma Abulangdang ultramafic intrusion in the Panxi region, SW China, is part of the Emeishan large igneous province (ELIP). The intrusion is composed of dunite and lherzolite with minor olivine gabbro. Olivine crystals in the dunite have Fo values from 89.0 to 86.5mol%. Chromite grains in both the dunite and lherzolite contain more than 0.5wt.% TiO2 and show a trend of increasing Fe3+ with increasing Fe2+/(Mg+Fe2+). Rocks of the intrusion have γOs(t) values from +0.1 to +1.2 and εNd(t) values from −1.9 to +2.9, similar to the high-Ti picrites, high-Ti flood basalts and Fe–Ti oxide-bearing, gabbroic intrusions of the ELIP. Modeling indicates that the Abulangdang intrusion formed by accumulation of olivine and chromite from a high-Ti picritic magma, whereas the high-Ti flood basalts and Fe–Ti oxide-bearing, gabbroic intrusions formed from derivative, evolved magmas after the early fractionation of minerals from the high-Ti picritic magma. Both the dunite and lherzolite have relatively high PGE concentrations and primitive mantle-normalized chalcophile element patterns with positive Os and Ru anomalies, in contrast to PGE-poor high-Ti flood basalts with negative Os and Ru anomalies. This is consistent with the retention of Ru–Os–Ir trace phases with olivine and chromite in the formation of the Abulangdang intrusion. Using a clinopyroxene geobarometer, the crystallization pressure of the Abulangdang intrusion is calculated to be 7.1 to 8.3kbar, equivalent to a depth of ~21 to 24km, which is deeper than that estimated for the Fe–Ti oxide-bearing, gabbroic layered intrusions of the ELIP (~5kbar). We propose that large volumes of mantle plume-derived high-Ti picritic magma underplating along the Moho boundary underwent early fractionation before eruption, and some high-Ti picritic magma ascended through a fossil conduit where the Abulangdang intrusion formed. Residual, evolved magmas either from the conduits or underplating magma chamber formed Fe–Ti oxide-bearing, gabbroic layered intrusions or high-Ti flood basalts. In this fashion, the Abulangdang intrusion resembles ultramafic portions that are missing in the Fe–Ti oxide-bearing, gabbroic intrusions of the ELIP. [Copyright &y& Elsevier]

Lead-free (1−x)(Ba0.85Ca0.15)(Zr0.1Ti0.9)O3-xNa0.5Bi0.5TiO3ceramics atx= 0.6–1.0 were synthesized by the solid-state reaction method. Phase structure, microstructure, and dielectric properties of the ceramics were investigated. X-ray diffraction patterns show pure perovskite structure for samples sintered at 1150°C atx= 0.7–1.0. Scanning electron microscope micrographs reveal obvious changes in shape and size of grains. Curie temperature and depolarization temperature of the system go upwards asxincreases, from 274°C and 87°C (x= 0.6) to 333°C and 157°C (x= 1.0). Obvious relaxation behaviors are observed. The highestϵrat Curie temperature is 3243 atx= 0.8, whenϵRT= 1353 and tanδ= 0.048. [ABSTRACT FROM AUTHOR]

About 140 million people worldwide live at an altitude above 2500 m. Studies have showed an increase of the incidence of hyperuricemia among plateau populations, but little is known about the possible mechanisms. This study aims to assess the effects of high altitude on hyperuricemia and explore the corresponding mechanisms at the histological, inflammatory and molecular levels. This study finds that intermittent hypobaric hypoxia (IHH) exposure results in an increase of serum uric acid level and a decrease of uric acid clearance rate. Compared with the control group, the IHH group shows significant increases in hemoglobin concentration (HGB) and red blood cell counts (RBC), indicating that high altitude hyperuricemia is associated with polycythemia. This study also shows that IHH exposure induces oxidative stress, which causes the injury of liver and renal structures and functions. Additionally, altered expressions of organic anion transporter 1 (OAT1) and organic cation transporter 1 (OCT1) of kidney have been detected in the IHH exposed rats. The adenosine deaminase (ADA) expression levels and the xanthione oxidase (XOD) and ADA activity of liver of the IHH exposure group have significantly increased compared with those of the control group. Furthermore, the spleen coefficients, IL-2, IL-1β and IL-8, have seen significant increases among the IHH exposure group. TLR/MyD88/NF-κB pathway is activated in the process of IHH induced inflammatory response in joints. Importantly, these results jointly show that IHH exposure causes hyperuricemia. IHH induced oxidative stress along with liver and kidney injury, unusual expression of the uric acid synthesis/excretion regulator and inflammatory response, thus suggesting a potential mechanism underlying IHH-induced hyperuricemia. [Display omitted] • High altitude hypoxia exposure induced hyperuricemia, which was associated with polycythemia. • Liver and kidney injury induced by oxidative stress is one of the possible mechanisms of high altitude hyperuricemia. • TLR/MyD88/NF-κB pathway participated in the high altitude hyperuricemia induced inflammatory response in the joint. [ABSTRACT FROM AUTHOR]