Coal and shale are both unconventional gas reservoirs. Comparison of pore characteristics in shale and coal would help understand organic pore structure in shale and investigate co-exploration of shale gas and coalbed...Coal and shale are both unconventional gas reservoirs. Comparison of pore characteristics in shale and coal would help understand organic pore structure in shale and investigate co-exploration of shale gas and coalbed methane in coal bearing strata. In this study, five shale samples and three coal samples of Taiyuan Formation were collected from Qinshui Basin, China. High pressure mercury injection, scanning electronic microscopy, and fractal theory have been used to compare pore characteristics in shale and coal. The results show that pore volumes in coal are much larger than that in shale, especially pores 3-100 nm. In coal, there are many semi-closed pores in micro pores （〈10 nm） and transition pores （10-100 nm）. On the contrary, micro pores and transition pores are mainly with open pores in shale. The fractal curves show that pores larger than 65 nm in coal and shale reservoir both have obvious self-similarity and the fractal dimension values in shale and coal are similar. But the fractal characteristics of pores smaller than 65 nm in shale reservoir are quite different from that in coal.展开更多
Fractal geometry is an important method in soil science,and many studies have used fractal theory to examine soil properties and the relationships with other eco-environmental factors.However,there have been few studi...Fractal geometry is an important method in soil science,and many studies have used fractal theory to examine soil properties and the relationships with other eco-environmental factors.However,there have been few studies examining soil particle volume fractal dimension in alpine grasslands.To study the volume fractal dimension of soil particles （D） and its relationships with soil salt,soil nutrient and plant species diversity,we conducted an experiment on an alpine grassland under different disturbance degrees：non-disturbance （N0）,light disturbance （L）,moderate disturbance （M） and heavy disturbance （H）.The results showed that （1） Ds varied from 2.573 to 2.635 among the different disturbance degrees and increased with increasing degrees of disturbance.（2） Shannon-Wiener diversity index,Pielou＇s evenness index and Margalef richness index reached their highest values at the M degree,indicating that moderate disturbance is beneficial to the increase of plant species diversity.（3） In the L and M degrees,there was a significant positive correlation between D and clay content and a significant negative correlation between D and soil organic matter （SOM）.In the H degree,D was significantly and positively correlated with total salt （TS）.The results suggested that to a certain extent,D can be used to characterize the uniformity of soil texture in addition to soil fertility characteristics.（4） For the L degree,there was a significant negative correlation between D and the Shannon-Wiener diversity index; while for the M degree,there was a significant negative correlation between D and Pielou＇s evenness index.展开更多
The hydrogen evolution reaction(HER) is a half-cell reaction in water electrolysis for producing hydrogen gas. In industrial water electrolysis, the HER is often conducted in alkaline media to achieve higher stability...The hydrogen evolution reaction(HER) is a half-cell reaction in water electrolysis for producing hydrogen gas. In industrial water electrolysis, the HER is often conducted in alkaline media to achieve higher stability of the electrode materials. However, the kinetics of the HER in alkaline medium is slow relative to that in acid because of the low concentration of protons in the former.Under the latter conditions, the entire HER process will require additional effort to obtain protons by water dissociation near or on the catalyst surface. Heterostructured catalysts, with fascinating synergistic effects derived from their heterogeneous interfaces, can provide multiple functional sites for the overall reaction process. At present, the activity of the most active known heterostructured catalysts surpasses(platinum-based heterostructures) or approaches (noble-metal-free heterostructures) that of the commercial Pt/C catalyst under alkaline conditions, demonstrating an infusive potential to break through the bottlenecks. This review summarizes the most representative and recent heterostructured HER catalysts for alkaline medium. The basics and principles of the HER under alkaline conditions are first introduced, followed by a discussion of the latest advances in heterostructured catalysts with/without noblemetal-based heterostructures. Special focus is placed on approaches for enhancing the reaction rate by accelerating the Volmer step. This review aims to provide an overview of the current developments in alkaline HER catalysts, as well as the design principles for the future development of heterostructured nano-or micro-sized electrocatalysts.展开更多
Lung cancer is the leading cause of cancer-related deaths. Traditional chemotherapy causes serious toxicity due to the wide bodily distribution of these drugs. Curcumin is a potential anticancer agent but its low wate...Lung cancer is the leading cause of cancer-related deaths. Traditional chemotherapy causes serious toxicity due to the wide bodily distribution of these drugs. Curcumin is a potential anticancer agent but its low water solubility, poor bioavailability and rapid metabolism significantly limits clinical applications. Here we developed a liposomal curcumin dry powder inhaler(LCD) for inhalation treatment of primary lung cancer. LCDs were obtained from curcumin liposomes after freeze-drying. The LCDs had a mass mean aerodynamic diameter of 5.81 μm and a fine particle fraction of 46.71%, suitable for pulmonary delivery. The uptake of curcumin liposomes by human lung cancer A549 cells was markedly greater and faster than that of free curcumin. The high cytotoxicity on A549 cells and the low cytotoxicity of curcumin liposomes on normal human bronchial BEAS-2B epithelial cells yielded a high selection index partly due to increased cell apoptosis. Curcumin powders, LCDs and gemcitabine were directly sprayed into the lungs of rats with lung cancer through the trachea. LCDs showed higher anticancer effects than the other two medications with regard to pathology and the expression of many cancer-related markers including VEGF, malondialdehyde, TNF-α, caspase-3 and BCL-2. LCDs are a promising medication for inhalation treatment of lung cancer with high therapeutic efficiency.展开更多
Mycotoxins are secondary metabolites of different species of fungi.Aflatoxin B1(AFB1),deoxynivalenol(DON),zearalenone(ZEN)and fumonisin B1(FB1)are the main mycotoxins contaminating animal feedstuffs.These mycotoxins c...Mycotoxins are secondary metabolites of different species of fungi.Aflatoxin B1(AFB1),deoxynivalenol(DON),zearalenone(ZEN)and fumonisin B1(FB1)are the main mycotoxins contaminating animal feedstuffs.These mycotoxins can primarily induce hepatotoxicity,immunotoxicity,neurotoxicity and nephrotoxicity,consequently cause adverse effects on the health and performance of animals.Therefore,physical,chemical,biological and nutritional regulation approaches have been developed as primary strategies for the decontamination and detoxification of these mycotoxins in the feed industry.Meanwhile,each of these techniques has its drawbacks,including inefficient,costly,or impractically applied on large scale.This review summarized the advantages and disadvantages of the different remediation strategies,as well as updates of the research progress of these strategies for AFB1,DON,ZEN and FB1 control in the feed industry.展开更多
In this work we prepared several CeO2-TiO2 catalysts for the NH3-SCR reactionusing co-precipitation with assistance of microwave irradiation.The catalytic NH3-SCR activities over CeO2-TiO2 catalysts at low temperature...In this work we prepared several CeO2-TiO2 catalysts for the NH3-SCR reactionusing co-precipitation with assistance of microwave irradiation.The catalytic NH3-SCR activities over CeO2-TiO2 catalysts at low temperatures are largely enhanced by the treatment of microwave irradiation,the operation temperature window is also broadened.For better understanding the promotion mechanism,the catalyst prepared by conventional co-precipitation with and without microwave irradiation treatment was characterized with H2-TPR,NH3-TPD,XPS,XRD and BET.Microwave irradiation treatment accelerates the crystallite rate of CeO2-TiO2 catalysts,and greatly enlarges their surface area by adjusting their microstructures.The resistance to SO2 and H2O is also improved via regulating the hierarchical pore structure by the microwave irradiation.Microwave irradiation treatment can also improve the redox property and increase the acid sites over the catalyst surfaces.The result of in situ DRIFTS suggests that the microwave irradiation treatment generates more Br?nsted acid sites on CeO2-TiO2-2 h catalyst,helpful in SCR reactions.XPS results show that after microwave irradiation on the CeO2-TiO2 catalysts,the surface demonstrates an elevated concentration of chemisorbed oxygen,consequently leading to better oxidation of NO to NO2.Additionally,the molar ratio of Ce3+/Ce4+has been elevated after being treated by microwave irradiation,a vital factor in enhancing the NH3-SCR activities.展开更多
To inactivate the potentially pathogenic microorganisms and safely utilize vegetable waste compost, ultra-high temperatures(> 70°C) should be maintained during the composting without having an inhibitory effec...To inactivate the potentially pathogenic microorganisms and safely utilize vegetable waste compost, ultra-high temperatures(> 70°C) should be maintained during the composting without having an inhibitory effect on maturity. This study investigated the influence of bulk density(part 1) and easily-degraded organic matter content(EDOMC, part 2) on temperature evolution during vegetable waste composting: Part 1: corn straw with different particle sizes was used to achieve different bulk densities in the composting material(BD1–BD3); Part 2: partial or total substitution of the corn straw by corn starch was carried out to obtain different EDOMC(ED1–ED4). The composting experiments were conducted in a labscale reactor(1.75 kg material) and lasted for 30 d. Temperature and CO2 emission were recorded daily, and the organic matter, lignocellulose, microbial activity, germination index(GI) and C/N of the samples were measured at different stages. The highest temperature(65.7°C) in part 1 occurred in the treatment with the bulk density of 0.35 g/cm3, which also had the longest thermophilic phase. Bulk density was found to seriously influence the utilization efficiency of O2 and heat transfer through materials, rather than heat production from organic matter degradation. In experiment part 2, the highest temperature was obtained with EDOMC of 45%(71.4°C). Therefore, adjusting the bulk density to 0.35 g/cm3 and the easily-degraded organic matter content of the initial material to 45% was the best combination for reaching temperatures above 70°C during composting, with no inhibitory effect on the maturity of the compost product.展开更多
Antibody-drug conjugates(ADCs)are gradually revolutionizing clinical cancer therapy.The antibody-drug conjugate linker molecule determines both the efficacy and the adverse effects,and so has a major influence on the ...Antibody-drug conjugates(ADCs)are gradually revolutionizing clinical cancer therapy.The antibody-drug conjugate linker molecule determines both the efficacy and the adverse effects,and so has a major influence on the fate of ADCs.An ideal linker should be stable in the circulatory system and release the cytotoxic payload specifically in the tumor.However,existing linkers often release payloads nonspecifically and inevitably lead to off-target toxicity.This defect is becoming an increasingly important factor that restricts the development of ADCs.The pursuit of ADCs with optimal therapeutic windows has resulted in remarkable progress in the discovery and development of novel linkers.The present review summarizes the advance of the chemical trigger,linker-antibody attachment and linker-payload attachment over the last 5 years,and describes the ADMET properties of ADCs.This work also helps clarify future developmental directions for the linkers.展开更多
The problem of cooperative circular formation with limited target information for multiple Unmanned Aerial Vehicle(UAV)system is addressed in this paper.A pigeon-inspired circular formation control method is proposed ...The problem of cooperative circular formation with limited target information for multiple Unmanned Aerial Vehicle(UAV)system is addressed in this paper.A pigeon-inspired circular formation control method is proposed to form the desired circular distribution in a plane based on the intelligent pigeon behavior during hovering.To reach the goal of prescribed radius and angular distribution,the controller is designed consisting of a circular movement part and a formation distribution part.Therein,the circular movement part is designed to make each UAV rotate around the speci-ed circle at the same angular speed only using the relative position between the UAV and the target.The formation distribution part could adjust the angular distance between each UAV and its neighbors with the jointly connected network to reduce communication cost.To smooth the speed variation,nonlinear PID-type method is delivered throughout the evolution of the system.The convergence analysis of the proposed control protocol is presented using Lyapunov theory and graph tools.The e®ectiveness of the proposed control strategies is demonstrated through numerical simulations.展开更多
OBJECTIVE:To characterize naringenin(NAR) population pharmacokinetics(PPK) in Chinese women with primary osteoporosis.METHODS:Ninety-eight female patients with primary osteoporosis from the Jingshan,Beixinqiao,Jiaodao...OBJECTIVE:To characterize naringenin(NAR) population pharmacokinetics(PPK) in Chinese women with primary osteoporosis.METHODS:Ninety-eight female patients with primary osteoporosis from the Jingshan,Beixinqiao,Jiaodaokou,Chaoyangmen,and Donghuamen communities in Beijing,China,aged 40 to 80 years,received oral Qianggu capsules(250 mg).Blood samples were collected before and at 0.5,1,2,3,4,6,8,10,12,and 24 h after administration.The concentration of NAR in the blood samples was measured using high performance liquid chromatography-tandem mass spectrometry.PPK analyses were performed with nonlinear mixed-effect modeling software(version 7.1.2,PsN3.2.12).The clearance(C1),central distribution volume(V),absorption rate constant(Ka1),peripheral distribution volume(VII),and inter-compartmental clearance(CLII) were set as parameters and estimated by the base model,covariate model,and final model.Kidney-Yang deficiency[Shenyangxu(SYAX)]and liver-kidney-Yin deficiency(Ganshenyinxu) are patterns of symptoms in Traditional Chinese Medicine that were set as covariates,along with age,height,blood urea nitrogen,serum creatinine,alanine transaminase,aspartate transaminase,and hyperlipidemia.Both stepwise forward and backward procedures were accomplished to build models.The final model was evaluated by internal and external validation,visual predictive check,bootstrap,and leverage analysis.RESULTS:A one compartment open model with first order degradation was the best fitted to the concentration-time profiles following oral administration of NAR.The mean of population parameters of the final model,C1,SYAX on C1,V,Ka1,CLII,and VII,were measured to be 37.6 L/h,0.427 L,123 L/h,0.12/h,0.3056,and 1.446,respectively.Inter-individual variability was estimated and SYAX was identified as a significant covariate.CONCLUSION:The population pharmacokinetic model described in this study could effectively characterize the pharmacokinetic profile of NAR following administration of a single dose of oral Qianggu capsules in Chinese women with prima展开更多
It is very difficult to clearly detect the location of a burning area in a coal mine since it is hidden underground.So we conducted research on the distribution of the burning area before controlling it.Firstly,the or...It is very difficult to clearly detect the location of a burning area in a coal mine since it is hidden underground.So we conducted research on the distribution of the burning area before controlling it.Firstly,the original drilling technique was used to analyze and determine the loose and scope of caving of burning area through field test,and then obtained the gases and the temperature data in this area were according to the borehole data.By analyzing these data,we found out that the location of burning area concentrated in the loose and caving area;and finally,the location and development of the burning area within the tested area were accurately determined.Based on this theory,we used the ground penetrating radar(GPR) to find out the loose and caving scale in the burning area during the control process of the burning area,and then located the fire-extinguishing boreholes within target which we used to control burning fire in the section.A mobile comprehensive fire prevention and extinguishing system based on the three-phase foam fire prevention and control technique was then adopted and conducted in the burning area which took only 9 months to extinguish the 227,000 m 2 of burning area of 9# coal.This control technology and experience will provide a very important reference to the control of other coalfield fire and hillock fire in the future.展开更多
Visible-light color flters using patterned nanostructures have attracted much interest due to their various advantages such as compactness,enhanced stability,and environmental friendliness compared with traditional pi...Visible-light color flters using patterned nanostructures have attracted much interest due to their various advantages such as compactness,enhanced stability,and environmental friendliness compared with traditional pigment or dye-based optical flters.While most existing studies are based on planar nanostructures with lateral variation in size,shape,and arrangement,the vertical dimension of structures is a long-ignored degree of freedom for the structural colors.Herein,we demonstrate a synthetic platform for transmissive color flter array by coordinated manipulations between height-varying nanocavities and their lateral flling fractions.Te thickness variation of those nanocavities has been fully deployed as an alternative degree of freedom,yielding vivid colors with wide gamut and excellent saturation.Experimental results show that the color-rendering capability of the pixelated nanocavities can be still retained as pixels are miniaturized to 500 nm.Crosstalk between closely spaced pixels of a Bayer color flter arrangement was calculated,showing minimal crosstalk for 1μm2 square subpixels.Our work provides an approach to designing and fabricating ultracompact color flter arrays for various potential applications including stained-glass microprints,microspectrometers,and high-resolution image sensing systems.展开更多
Background:High stocking density(HSD)stress has detrimental effects on growth performance,intestinal barrier function,and intestinal microbiota in intensive animal production.Organic acids(OA)are widely used as feed a...Background:High stocking density(HSD)stress has detrimental effects on growth performance,intestinal barrier function,and intestinal microbiota in intensive animal production.Organic acids(OA)are widely used as feed addi-tives for their ability to improve growth performance and intestinal health in poultry.However,whether dietary OA can ameliorate HSD stress-induced impaired intestinal barrier in broilers remains elusive.In this study,a total of 528 one-day-old male Arbor Acres broilers were randomly allocated into 3 treatments with 12 replicates per treatment including 10 birds for normal stocking density and 17 birds for HSD.The dietary treatments were as follows:1)Normal stocking density+basal diet;2)HSD+basal diets;3)HSD+OA.Results:HSD stress can induce increased levels of serum corticosterone,lipopolysaccharides,interleukin-1β,tumor necrosis factor-α,and down-regulated mRNA expression of ZO-1,resulting in compromised growth performance of broilers(P<0.05).Dietary OA could significantly reduce levels of serum corticosterone,lipopolysaccharides,interleukin-1β,and tumor necrosis factor-α,which were accompanied by up-regulated interleukin-10,mRNA expres-sion of ZO-1,and growth performance(P<0.05).Moreover,OA could down-regulate the mRNA expression of TLR4 and MyD88 to inhibit the NF-κB signaling pathway(P<0.05).Additionally,HSD stress significantly decreased the abundance of Bacteroidetes and disturbed the balance of microbial ecosystems,whereas OA significantly increased the abundance of Bacteroidetes and restored the disordered gut microbiota by reducing competitive and exploita-tive interactions in microbial communities(P<0.05).Meanwhile,OA significantly increased the content of acetic and butyric acids,which showed significant correlations with intestinal inflammation indicators(P<0.05).Conclusions:Dietary OA ameliorated intestinal inflammation and growth performance of broilers through restor-ing the disordered gut microbial compositions and interactions induced by HSD and elevating short-chain fatty a展开更多
Single-nucleotide polymorphisms contribute to phenotypic diversity in maize. Creation and functional annotation of point mutations has been limited by the low efficiency of conventional methods based on random mutatio...Single-nucleotide polymorphisms contribute to phenotypic diversity in maize. Creation and functional annotation of point mutations has been limited by the low efficiency of conventional methods based on random mutation. An efficient tool for generating targeted single-base mutations is desirable for both functional genomics and precise genetic improvement. The objective of this study was to test the efficiency of targeted C-to-T base editing of two non-allelic acetolactate synthase(ALS) in generating sulfonylurea herbicide-resistant mutants. A CRISPR/Cas9 nickase-cytidine deaminase fused with uracil DNA glycosylase inhibitor(UGI) was employed to achieve targeted conversion of cytosine to thymine in ZmALS1 and ZmALS2. Both protoplasts and recovered mutant plants showed the activity of the cytosine base editor, with an in vivo efficiency of up to 13.8%. Transgene-free edited plants harboring a homozygous ZmALS1 mutation or a ZmALS1 and ZmALS2 double mutation were tested for their resistance at a dose of up to 15-fold the recommended limit of chlorsulfuron, a sulfonylurea herbicide widely used in agriculture. Targeted base editing of C-to-T per se and a phenotype verified in the generated mutants demonstrates the power of base editing in precise maize breeding.展开更多
The atomistic structures of solid–solid interfaces are of fundamental interests for understanding physical properties of interfacial materials. However, determination of interface structures faces a substantial chall...The atomistic structures of solid–solid interfaces are of fundamental interests for understanding physical properties of interfacial materials. However, determination of interface structures faces a substantial challenge, both experimentally and theoretically. Here, we propose an efficient method for predicting interface structures via the generalization of our in-house developed CALYPSO method for structure prediction. We devised a lattice match toolkit that allows us to automatically search for the optimal latticematched superlattice for construction of the interface structures. In addition, bonding constraints(e.g.,constraints on interatomic distances and coordination numbers of atoms) are imposed to generate better starting interface structures by taking advantages of the known bonding environment derived from the stable bulk phases. The interface structures evolve by following interfacially confined swarm intelligence algorithm, which is known to be efficient for exploration of potential energy surface. The method was validated by correctly predicting a number of known interface structures with only given information of two parent solids. The application of the developed method leads to prediction of two unknown grain boundary(GB) structures(r-GB and p-GB) of rutile TiO_2 ∑5(2 1 0) under an O reducing atmosphere that contained Ti^(3+)as the result of O defects. Further calculations revealed that the intrinsic band gap of p-GB is reduced to 0.7 eV owing to substantial broadening of the Ti-3 d interfacial levels from Ti^(3+)centers.Our results demonstrated that introduction of grain boundaries is an effective strategy to engineer the electronic properties and thus enhance the visible-light photoactivity of TiO_2.展开更多
Increasing yield is one of the most important goals in crop breeding. Soybean （Glycine max L. Merr.）, one of the most economically important leguminous seed crops, provides the majority of plant proteins, and more t...Increasing yield is one of the most important goals in crop breeding. Soybean （Glycine max L. Merr.）, one of the most economically important leguminous seed crops, provides the majority of plant proteins, and more than a quarter of the world＇s food and animal feed （Graham and Vance, 2003）. The yield of soybean is finally determined by the number of seeds per unit area, which affected by many characters, such as height, branching number, photosynthesis, seed size, seed number. The number of seeds per pod is taken for one of the critical components that related to yield （You et al., 1995）.展开更多
OBJECTIVE: To systematically examine the postmarketing safety of depside salt injection made from Danshen(Radix Salviae Miltiorrhizae),identifythe potential risk factors, and ensure its clinical safety.METHODS: We exa...OBJECTIVE: To systematically examine the postmarketing safety of depside salt injection made from Danshen(Radix Salviae Miltiorrhizae),identifythe potential risk factors, and ensure its clinical safety.METHODS: We examined a comprehensive series of studies on the production process, quality standards, pharmacology, population pharmacokinetics, and safety evaluation of depside salt injection made from Danshen(Radix Salviae Miltiorrhizae). Data from Ⅰ-Ⅳ clinical drug trials, hospital information systems(HIS), and spontaneous reporting systems(SRS) were also analyzed.RESULTS: The effective components of salvianolic acid salt content reached almost 100%, and the magnesium lithospermate B content reached morethan 80%. The median lethal dose(LD50) calculated by the Bliss method was 1.49 g/kg, with 95%confidence intervals of 1.29-1.72 g/kg. Long-term tests on Beagle dogs indicated that doses of less than 80 mg/kg were safe and doses of 320 mg/kg were toxic. Adverse drug reactions(ADRs) included digestive disorders; drug-induced erythrocyte deformation in lung, liver, spleen, kidney, bone marrow, intestinal mucosa, lymph nodes, and other tissues; megakaryocytes in lung, liver, and spleen resulting from mild hemolysis; and mild hyperplasia in bone marrow hematopoietic tissue. Other studies indicated no irritative effect of the injection on local tissues and blood vessels, and no allergic reactions, erythrocyte coagulation, or hemolysis. SRS data showed that the most common ADRs were headache, head distention, dizziness, facial flushing, skin itching, thrombocytopenia, and the reversibility of elevated Aspartate transaminase. HIS data indicated no damage to renal function from using depside salt injection made from Danshen(Radix Salviae Miltiorrhizae) at a dosage higher than the recommended dose.CONCLUSION: This study analyzes the clinical characteristics of ADRs from depside salt injection made from Danshen(Radix Salviae Miltiorrhizae),and discusses the factors influencing such reactions. It provides scientific refere展开更多
基金The authors thank the National Science Foundation of China （41472135）, the Research and Innovation Project for College Graduates of Jiangsu Province （KYLX15-1396）, the Scientific Research Foundation of the Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process, Ministry of Education （China University of Mining and Technology） （No. 2015-04） for the support of the research.
文摘Coal and shale are both unconventional gas reservoirs. Comparison of pore characteristics in shale and coal would help understand organic pore structure in shale and investigate co-exploration of shale gas and coalbed methane in coal bearing strata. In this study, five shale samples and three coal samples of Taiyuan Formation were collected from Qinshui Basin, China. High pressure mercury injection, scanning electronic microscopy, and fractal theory have been used to compare pore characteristics in shale and coal. The results show that pore volumes in coal are much larger than that in shale, especially pores 3-100 nm. In coal, there are many semi-closed pores in micro pores （〈10 nm） and transition pores （10-100 nm）. On the contrary, micro pores and transition pores are mainly with open pores in shale. The fractal curves show that pores larger than 65 nm in coal and shale reservoir both have obvious self-similarity and the fractal dimension values in shale and coal are similar. But the fractal characteristics of pores smaller than 65 nm in shale reservoir are quite different from that in coal.
基金financially supported by the National Basic Research Program of China(2009CB825103)
文摘Fractal geometry is an important method in soil science,and many studies have used fractal theory to examine soil properties and the relationships with other eco-environmental factors.However,there have been few studies examining soil particle volume fractal dimension in alpine grasslands.To study the volume fractal dimension of soil particles （D） and its relationships with soil salt,soil nutrient and plant species diversity,we conducted an experiment on an alpine grassland under different disturbance degrees：non-disturbance （N0）,light disturbance （L）,moderate disturbance （M） and heavy disturbance （H）.The results showed that （1） Ds varied from 2.573 to 2.635 among the different disturbance degrees and increased with increasing degrees of disturbance.（2） Shannon-Wiener diversity index,Pielou＇s evenness index and Margalef richness index reached their highest values at the M degree,indicating that moderate disturbance is beneficial to the increase of plant species diversity.（3） In the L and M degrees,there was a significant positive correlation between D and clay content and a significant negative correlation between D and soil organic matter （SOM）.In the H degree,D was significantly and positively correlated with total salt （TS）.The results suggested that to a certain extent,D can be used to characterize the uniformity of soil texture in addition to soil fertility characteristics.（4） For the L degree,there was a significant negative correlation between D and the Shannon-Wiener diversity index; while for the M degree,there was a significant negative correlation between D and Pielou＇s evenness index.
基金financial support provided by National Natural Science Foundation of China (Nos.61301026 and 51802073)the supports from the Talent Introduction Foundation (No.ZRC2014448)+1 种基金the Key Discipline Foundation (No.AKZDXK2015A01) of Anhui Science and Technology Universitythe financial support by the Singapore National Research Foundation under its Campus for Research Excellence And Technological Enterprise (CREATE) program through the Cambridge Center for Carbon Reduction in Chemical Technology (C4T) and eCO2EP programs
文摘The hydrogen evolution reaction(HER) is a half-cell reaction in water electrolysis for producing hydrogen gas. In industrial water electrolysis, the HER is often conducted in alkaline media to achieve higher stability of the electrode materials. However, the kinetics of the HER in alkaline medium is slow relative to that in acid because of the low concentration of protons in the former.Under the latter conditions, the entire HER process will require additional effort to obtain protons by water dissociation near or on the catalyst surface. Heterostructured catalysts, with fascinating synergistic effects derived from their heterogeneous interfaces, can provide multiple functional sites for the overall reaction process. At present, the activity of the most active known heterostructured catalysts surpasses(platinum-based heterostructures) or approaches (noble-metal-free heterostructures) that of the commercial Pt/C catalyst under alkaline conditions, demonstrating an infusive potential to break through the bottlenecks. This review summarizes the most representative and recent heterostructured HER catalysts for alkaline medium. The basics and principles of the HER under alkaline conditions are first introduced, followed by a discussion of the latest advances in heterostructured catalysts with/without noblemetal-based heterostructures. Special focus is placed on approaches for enhancing the reaction rate by accelerating the Volmer step. This review aims to provide an overview of the current developments in alkaline HER catalysts, as well as the design principles for the future development of heterostructured nano-or micro-sized electrocatalysts.
文摘Lung cancer is the leading cause of cancer-related deaths. Traditional chemotherapy causes serious toxicity due to the wide bodily distribution of these drugs. Curcumin is a potential anticancer agent but its low water solubility, poor bioavailability and rapid metabolism significantly limits clinical applications. Here we developed a liposomal curcumin dry powder inhaler(LCD) for inhalation treatment of primary lung cancer. LCDs were obtained from curcumin liposomes after freeze-drying. The LCDs had a mass mean aerodynamic diameter of 5.81 μm and a fine particle fraction of 46.71%, suitable for pulmonary delivery. The uptake of curcumin liposomes by human lung cancer A549 cells was markedly greater and faster than that of free curcumin. The high cytotoxicity on A549 cells and the low cytotoxicity of curcumin liposomes on normal human bronchial BEAS-2B epithelial cells yielded a high selection index partly due to increased cell apoptosis. Curcumin powders, LCDs and gemcitabine were directly sprayed into the lungs of rats with lung cancer through the trachea. LCDs showed higher anticancer effects than the other two medications with regard to pathology and the expression of many cancer-related markers including VEGF, malondialdehyde, TNF-α, caspase-3 and BCL-2. LCDs are a promising medication for inhalation treatment of lung cancer with high therapeutic efficiency.
基金supported by the Chinese Natural Sciences (32072775 and 31772636)Nutreco N.V.(Netherlands)
文摘Mycotoxins are secondary metabolites of different species of fungi.Aflatoxin B1(AFB1),deoxynivalenol(DON),zearalenone(ZEN)and fumonisin B1(FB1)are the main mycotoxins contaminating animal feedstuffs.These mycotoxins can primarily induce hepatotoxicity,immunotoxicity,neurotoxicity and nephrotoxicity,consequently cause adverse effects on the health and performance of animals.Therefore,physical,chemical,biological and nutritional regulation approaches have been developed as primary strategies for the decontamination and detoxification of these mycotoxins in the feed industry.Meanwhile,each of these techniques has its drawbacks,including inefficient,costly,or impractically applied on large scale.This review summarized the advantages and disadvantages of the different remediation strategies,as well as updates of the research progress of these strategies for AFB1,DON,ZEN and FB1 control in the feed industry.
基金Project supported by the National Natural Science Foundation of China(21577005)the National Key Research and Development Program of China(2016YFB0600400)
文摘In this work we prepared several CeO2-TiO2 catalysts for the NH3-SCR reactionusing co-precipitation with assistance of microwave irradiation.The catalytic NH3-SCR activities over CeO2-TiO2 catalysts at low temperatures are largely enhanced by the treatment of microwave irradiation,the operation temperature window is also broadened.For better understanding the promotion mechanism,the catalyst prepared by conventional co-precipitation with and without microwave irradiation treatment was characterized with H2-TPR,NH3-TPD,XPS,XRD and BET.Microwave irradiation treatment accelerates the crystallite rate of CeO2-TiO2 catalysts,and greatly enlarges their surface area by adjusting their microstructures.The resistance to SO2 and H2O is also improved via regulating the hierarchical pore structure by the microwave irradiation.Microwave irradiation treatment can also improve the redox property and increase the acid sites over the catalyst surfaces.The result of in situ DRIFTS suggests that the microwave irradiation treatment generates more Br?nsted acid sites on CeO2-TiO2-2 h catalyst,helpful in SCR reactions.XPS results show that after microwave irradiation on the CeO2-TiO2 catalysts,the surface demonstrates an elevated concentration of chemisorbed oxygen,consequently leading to better oxidation of NO to NO2.Additionally,the molar ratio of Ce3+/Ce4+has been elevated after being treated by microwave irradiation,a vital factor in enhancing the NH3-SCR activities.
基金supported by the National Science and Technology Pillar Program in Rural Areas (No. 2013BAD20B01)China Special Fund for Agricultural Research in the Public Interest (No. 201303079)
文摘To inactivate the potentially pathogenic microorganisms and safely utilize vegetable waste compost, ultra-high temperatures(> 70°C) should be maintained during the composting without having an inhibitory effect on maturity. This study investigated the influence of bulk density(part 1) and easily-degraded organic matter content(EDOMC, part 2) on temperature evolution during vegetable waste composting: Part 1: corn straw with different particle sizes was used to achieve different bulk densities in the composting material(BD1–BD3); Part 2: partial or total substitution of the corn straw by corn starch was carried out to obtain different EDOMC(ED1–ED4). The composting experiments were conducted in a labscale reactor(1.75 kg material) and lasted for 30 d. Temperature and CO2 emission were recorded daily, and the organic matter, lignocellulose, microbial activity, germination index(GI) and C/N of the samples were measured at different stages. The highest temperature(65.7°C) in part 1 occurred in the treatment with the bulk density of 0.35 g/cm3, which also had the longest thermophilic phase. Bulk density was found to seriously influence the utilization efficiency of O2 and heat transfer through materials, rather than heat production from organic matter degradation. In experiment part 2, the highest temperature was obtained with EDOMC of 45%(71.4°C). Therefore, adjusting the bulk density to 0.35 g/cm3 and the easily-degraded organic matter content of the initial material to 45% was the best combination for reaching temperatures above 70°C during composting, with no inhibitory effect on the maturity of the compost product.
基金funded by the Chinese National Natural Science Foundation(Grant Nos.81872736 and 81903451)the China Postdoctoral Science Foundation(Grant No.2019M664015)。
文摘Antibody-drug conjugates(ADCs)are gradually revolutionizing clinical cancer therapy.The antibody-drug conjugate linker molecule determines both the efficacy and the adverse effects,and so has a major influence on the fate of ADCs.An ideal linker should be stable in the circulatory system and release the cytotoxic payload specifically in the tumor.However,existing linkers often release payloads nonspecifically and inevitably lead to off-target toxicity.This defect is becoming an increasingly important factor that restricts the development of ADCs.The pursuit of ADCs with optimal therapeutic windows has resulted in remarkable progress in the discovery and development of novel linkers.The present review summarizes the advance of the chemical trigger,linker-antibody attachment and linker-payload attachment over the last 5 years,and describes the ADMET properties of ADCs.This work also helps clarify future developmental directions for the linkers.
基金This work was partially supported by Science and Technology Innovation 2030-Key Project of\New Generation Arti-cial Intelligence"under the Grant No.2018AAA0102405National Natural Science Foundation of China under the Grant Nos.91948204,U20B2071,U1913602,and U19B2033.
文摘The problem of cooperative circular formation with limited target information for multiple Unmanned Aerial Vehicle(UAV)system is addressed in this paper.A pigeon-inspired circular formation control method is proposed to form the desired circular distribution in a plane based on the intelligent pigeon behavior during hovering.To reach the goal of prescribed radius and angular distribution,the controller is designed consisting of a circular movement part and a formation distribution part.Therein,the circular movement part is designed to make each UAV rotate around the speci-ed circle at the same angular speed only using the relative position between the UAV and the target.The formation distribution part could adjust the angular distance between each UAV and its neighbors with the jointly connected network to reduce communication cost.To smooth the speed variation,nonlinear PID-type method is delivered throughout the evolution of the system.The convergence analysis of the proposed control protocol is presented using Lyapunov theory and graph tools.The e®ectiveness of the proposed control strategies is demonstrated through numerical simulations.
基金Supported by Grant from Significant Drug Research and Development in Important State Science and Technology Specific And Key Technique Research(Key Issues Research on Re-evaluation of Listed Herbal Hedicine,No.2009ZX09502-030)Visiting Fellow Joint Innovation Research Project of The China Academy of Chinese Medical Sciences(Exploratory Research in Population Pharmacokinetics of Bioactive Compounds of Osteopractic Total Flavone Based on Total Quantum Statistical Moment.No.ZZ070834)
文摘OBJECTIVE:To characterize naringenin(NAR) population pharmacokinetics(PPK) in Chinese women with primary osteoporosis.METHODS:Ninety-eight female patients with primary osteoporosis from the Jingshan,Beixinqiao,Jiaodaokou,Chaoyangmen,and Donghuamen communities in Beijing,China,aged 40 to 80 years,received oral Qianggu capsules(250 mg).Blood samples were collected before and at 0.5,1,2,3,4,6,8,10,12,and 24 h after administration.The concentration of NAR in the blood samples was measured using high performance liquid chromatography-tandem mass spectrometry.PPK analyses were performed with nonlinear mixed-effect modeling software(version 7.1.2,PsN3.2.12).The clearance(C1),central distribution volume(V),absorption rate constant(Ka1),peripheral distribution volume(VII),and inter-compartmental clearance(CLII) were set as parameters and estimated by the base model,covariate model,and final model.Kidney-Yang deficiency[Shenyangxu(SYAX)]and liver-kidney-Yin deficiency(Ganshenyinxu) are patterns of symptoms in Traditional Chinese Medicine that were set as covariates,along with age,height,blood urea nitrogen,serum creatinine,alanine transaminase,aspartate transaminase,and hyperlipidemia.Both stepwise forward and backward procedures were accomplished to build models.The final model was evaluated by internal and external validation,visual predictive check,bootstrap,and leverage analysis.RESULTS:A one compartment open model with first order degradation was the best fitted to the concentration-time profiles following oral administration of NAR.The mean of population parameters of the final model,C1,SYAX on C1,V,Ka1,CLII,and VII,were measured to be 37.6 L/h,0.427 L,123 L/h,0.12/h,0.3056,and 1.446,respectively.Inter-individual variability was estimated and SYAX was identified as a significant covariate.CONCLUSION:The population pharmacokinetic model described in this study could effectively characterize the pharmacokinetic profile of NAR following administration of a single dose of oral Qianggu capsules in Chinese women with prima
基金funded by the National Natural Science Foundation of China (No. 51134020)the State Key Laboratory of Coal Resources and Mine Safety Foundation (No.SKLCRSM08x06)the Natural Science Foundation of Jiangsu Province (No. BK2009004)
文摘It is very difficult to clearly detect the location of a burning area in a coal mine since it is hidden underground.So we conducted research on the distribution of the burning area before controlling it.Firstly,the original drilling technique was used to analyze and determine the loose and scope of caving of burning area through field test,and then obtained the gases and the temperature data in this area were according to the borehole data.By analyzing these data,we found out that the location of burning area concentrated in the loose and caving area;and finally,the location and development of the burning area within the tested area were accurately determined.Based on this theory,we used the ground penetrating radar(GPR) to find out the loose and caving scale in the burning area during the control process of the burning area,and then located the fire-extinguishing boreholes within target which we used to control burning fire in the section.A mobile comprehensive fire prevention and extinguishing system based on the three-phase foam fire prevention and control technique was then adopted and conducted in the burning area which took only 9 months to extinguish the 227,000 m 2 of burning area of 9# coal.This control technology and experience will provide a very important reference to the control of other coalfield fire and hillock fire in the future.
基金Te authors gratefully acknowledge the fnancial support from the National Natural Science Foundation of China(Grant nos.51722503 and 11574078).
文摘Visible-light color flters using patterned nanostructures have attracted much interest due to their various advantages such as compactness,enhanced stability,and environmental friendliness compared with traditional pigment or dye-based optical flters.While most existing studies are based on planar nanostructures with lateral variation in size,shape,and arrangement,the vertical dimension of structures is a long-ignored degree of freedom for the structural colors.Herein,we demonstrate a synthetic platform for transmissive color flter array by coordinated manipulations between height-varying nanocavities and their lateral flling fractions.Te thickness variation of those nanocavities has been fully deployed as an alternative degree of freedom,yielding vivid colors with wide gamut and excellent saturation.Experimental results show that the color-rendering capability of the pixelated nanocavities can be still retained as pixels are miniaturized to 500 nm.Crosstalk between closely spaced pixels of a Bayer color flter arrangement was calculated,showing minimal crosstalk for 1μm2 square subpixels.Our work provides an approach to designing and fabricating ultracompact color flter arrays for various potential applications including stained-glass microprints,microspectrometers,and high-resolution image sensing systems.
基金supported by the Agricultural Science and Technology Innovation Program(ASTIP)of the Chinese Academy of Agricultural Sciences,and Trouw Nutrition Research&Development Centers.
文摘Background:High stocking density(HSD)stress has detrimental effects on growth performance,intestinal barrier function,and intestinal microbiota in intensive animal production.Organic acids(OA)are widely used as feed addi-tives for their ability to improve growth performance and intestinal health in poultry.However,whether dietary OA can ameliorate HSD stress-induced impaired intestinal barrier in broilers remains elusive.In this study,a total of 528 one-day-old male Arbor Acres broilers were randomly allocated into 3 treatments with 12 replicates per treatment including 10 birds for normal stocking density and 17 birds for HSD.The dietary treatments were as follows:1)Normal stocking density+basal diet;2)HSD+basal diets;3)HSD+OA.Results:HSD stress can induce increased levels of serum corticosterone,lipopolysaccharides,interleukin-1β,tumor necrosis factor-α,and down-regulated mRNA expression of ZO-1,resulting in compromised growth performance of broilers(P<0.05).Dietary OA could significantly reduce levels of serum corticosterone,lipopolysaccharides,interleukin-1β,and tumor necrosis factor-α,which were accompanied by up-regulated interleukin-10,mRNA expres-sion of ZO-1,and growth performance(P<0.05).Moreover,OA could down-regulate the mRNA expression of TLR4 and MyD88 to inhibit the NF-κB signaling pathway(P<0.05).Additionally,HSD stress significantly decreased the abundance of Bacteroidetes and disturbed the balance of microbial ecosystems,whereas OA significantly increased the abundance of Bacteroidetes and restored the disordered gut microbiota by reducing competitive and exploita-tive interactions in microbial communities(P<0.05).Meanwhile,OA significantly increased the content of acetic and butyric acids,which showed significant correlations with intestinal inflammation indicators(P<0.05).Conclusions:Dietary OA ameliorated intestinal inflammation and growth performance of broilers through restor-ing the disordered gut microbial compositions and interactions induced by HSD and elevating short-chain fatty a
基金supported by the Key Area Research and Development Program of Guangdong Province(2018B020202008)the National Natural Science Foundation of China(31771808)+2 种基金Beijing Municipal Science and Technology Project(D171100007717001)the National Key Research and Development Program of China(2016YFD0101803)National Engineering Laboratory for Crop Molecular Breeding。
文摘Single-nucleotide polymorphisms contribute to phenotypic diversity in maize. Creation and functional annotation of point mutations has been limited by the low efficiency of conventional methods based on random mutation. An efficient tool for generating targeted single-base mutations is desirable for both functional genomics and precise genetic improvement. The objective of this study was to test the efficiency of targeted C-to-T base editing of two non-allelic acetolactate synthase(ALS) in generating sulfonylurea herbicide-resistant mutants. A CRISPR/Cas9 nickase-cytidine deaminase fused with uracil DNA glycosylase inhibitor(UGI) was employed to achieve targeted conversion of cytosine to thymine in ZmALS1 and ZmALS2. Both protoplasts and recovered mutant plants showed the activity of the cytosine base editor, with an in vivo efficiency of up to 13.8%. Transgene-free edited plants harboring a homozygous ZmALS1 mutation or a ZmALS1 and ZmALS2 double mutation were tested for their resistance at a dose of up to 15-fold the recommended limit of chlorsulfuron, a sulfonylurea herbicide widely used in agriculture. Targeted base editing of C-to-T per se and a phenotype verified in the generated mutants demonstrates the power of base editing in precise maize breeding.
基金supported by the National Natural Science Foundation of China(11774127,11822404 and 11534003)the National Key Research and Development Program of China(2016YFB0201200,2016YFB0201201,and 2016YFB0201204)+1 种基金the Program for JLU Science and Technology Innovative Research Team(JLUSTIRT)the Science Challenge Project(TZ2016001)
文摘The atomistic structures of solid–solid interfaces are of fundamental interests for understanding physical properties of interfacial materials. However, determination of interface structures faces a substantial challenge, both experimentally and theoretically. Here, we propose an efficient method for predicting interface structures via the generalization of our in-house developed CALYPSO method for structure prediction. We devised a lattice match toolkit that allows us to automatically search for the optimal latticematched superlattice for construction of the interface structures. In addition, bonding constraints(e.g.,constraints on interatomic distances and coordination numbers of atoms) are imposed to generate better starting interface structures by taking advantages of the known bonding environment derived from the stable bulk phases. The interface structures evolve by following interfacially confined swarm intelligence algorithm, which is known to be efficient for exploration of potential energy surface. The method was validated by correctly predicting a number of known interface structures with only given information of two parent solids. The application of the developed method leads to prediction of two unknown grain boundary(GB) structures(r-GB and p-GB) of rutile TiO_2 ∑5(2 1 0) under an O reducing atmosphere that contained Ti^(3+)as the result of O defects. Further calculations revealed that the intrinsic band gap of p-GB is reduced to 0.7 eV owing to substantial broadening of the Ti-3 d interfacial levels from Ti^(3+)centers.Our results demonstrated that introduction of grain boundaries is an effective strategy to engineer the electronic properties and thus enhance the visible-light photoactivity of TiO_2.
基金supported by the National Natural Science Foundation of China(Grant Nos.31271297 and 31222042) "One-hundred talents" Startup Funds from Chinese Academy of SciencesNational Key Basic Research Program(No. 2009CB 118402)
文摘Increasing yield is one of the most important goals in crop breeding. Soybean （Glycine max L. Merr.）, one of the most economically important leguminous seed crops, provides the majority of plant proteins, and more than a quarter of the world＇s food and animal feed （Graham and Vance, 2003）. The yield of soybean is finally determined by the number of seeds per unit area, which affected by many characters, such as height, branching number, photosynthesis, seed size, seed number. The number of seeds per pod is taken for one of the critical components that related to yield （You et al., 1995）.
基金National Science and Technology Major Projects for"Major New Drugs Innovation and Development":Study on Key Technologies of Postmarketing Evaluation forChinese Medicine(No.2009ZX09502-030)
文摘OBJECTIVE: To systematically examine the postmarketing safety of depside salt injection made from Danshen(Radix Salviae Miltiorrhizae),identifythe potential risk factors, and ensure its clinical safety.METHODS: We examined a comprehensive series of studies on the production process, quality standards, pharmacology, population pharmacokinetics, and safety evaluation of depside salt injection made from Danshen(Radix Salviae Miltiorrhizae). Data from Ⅰ-Ⅳ clinical drug trials, hospital information systems(HIS), and spontaneous reporting systems(SRS) were also analyzed.RESULTS: The effective components of salvianolic acid salt content reached almost 100%, and the magnesium lithospermate B content reached morethan 80%. The median lethal dose(LD50) calculated by the Bliss method was 1.49 g/kg, with 95%confidence intervals of 1.29-1.72 g/kg. Long-term tests on Beagle dogs indicated that doses of less than 80 mg/kg were safe and doses of 320 mg/kg were toxic. Adverse drug reactions(ADRs) included digestive disorders; drug-induced erythrocyte deformation in lung, liver, spleen, kidney, bone marrow, intestinal mucosa, lymph nodes, and other tissues; megakaryocytes in lung, liver, and spleen resulting from mild hemolysis; and mild hyperplasia in bone marrow hematopoietic tissue. Other studies indicated no irritative effect of the injection on local tissues and blood vessels, and no allergic reactions, erythrocyte coagulation, or hemolysis. SRS data showed that the most common ADRs were headache, head distention, dizziness, facial flushing, skin itching, thrombocytopenia, and the reversibility of elevated Aspartate transaminase. HIS data indicated no damage to renal function from using depside salt injection made from Danshen(Radix Salviae Miltiorrhizae) at a dosage higher than the recommended dose.CONCLUSION: This study analyzes the clinical characteristics of ADRs from depside salt injection made from Danshen(Radix Salviae Miltiorrhizae),and discusses the factors influencing such reactions. It provides scientific refere
