The complex micro-interfacial interaction theories of heavy metal ions such as Pb(Ⅱ)and Cd(Ⅱ)adsorption on fine sediment in aqueous solution were not systematically investigated.The aim of this work was to reflect t...The complex micro-interfacial interaction theories of heavy metal ions such as Pb(Ⅱ)and Cd(Ⅱ)adsorption on fine sediment in aqueous solution were not systematically investigated.The aim of this work was to reflect the micro-interfacial adsorption characteristics.Sediment samples were collected from an estuary.The Isothermal and kinetics adsorption experiment were done to acquire the data.Isothermal,kinetics,film diffusion and intraparticle diffusion models were adopted to fit the adsorption experimental data.The results indicated that the Langmuir,Freundlich and Temkin models were suitable for analyzing the isothermal experimental data.The maximum adsorption capacities of Pb(Ⅱ)and Cd(Ⅱ)on the sediment were 1.1377 and 0.9821 mg·g-1,respectively.The qm and KL of the Langmuir model,Kf and nF of the Freundlich model,and b and A of the Temkin model all exhibited a power function relationship with the initial adsorbate concentration.The pseudo-second-order model provided a better fit for the experimental kinetics data compared with the fit of the pseudo-first-order and Elovich models.The pseudo-second-order parameters k2 and qe of Pb(Ⅱ)and qe of Cd(Ⅱ)both had a power function relationship with adsorption time,additionally,the k2 of Cd(Ⅱ)had an exponential function relationship with adsorption time.The liquid-film diffusion parameters kfd of Pb(Ⅱ)and Cd(Ⅱ)were 0.0569 and 0.1806 min1,respectively.The intraparticle diffusion parameter kid values of Pb(Ⅱ)and Cd(Ⅱ)were 0.0055 mg$g1$min1/2 and 0.0049 mg$g1$min1/2,respectively.The physical significance of the model parameters showed that Pb(Ⅱ)adsorption on sediment was stronger than Cd(Ⅱ).The results of this study provided a theoretical reference for the micro-interfacial mechanism of heavy metal ion adsorption on sediment.展开更多
Plant resistance against insects mainly depends on nutrient restriction and toxic metabolites, but the relative importance of nutrition and toxins remains elusive. We examined performance, nutrition ingestion, and tra...Plant resistance against insects mainly depends on nutrient restriction and toxic metabolites, but the relative importance of nutrition and toxins remains elusive. We examined performance, nutrition ingestion, and transcriptome response of the English grain aphid, Sitobion avenae, feeding on resistant Xiaoyan 22(XY22) and susceptible Xinong 979(XN979) wheat cultivars. Aphids had lower body weight and fecundity when feeding on XY22 than on XN979, although the phloem sap of XY22 had a higher nutritive quality(in terms of amino acid:sucrose ratio). Aphids feeding on XY22 also had a lower honeydew excretion rate than those on XN979, suggesting that aphids ingested less phloem sap from XY22. The transcriptome data showed 600 differentially expressed genes(DEGs), and 11 of the top 20 KEGG pathways significantly enriched in DEGs were involved in nutrient metabolism. We found 81 DEGs associated with the metabolism of sugars, lipids, and amino acids, 59 of which were significantly downregulated in aphids feeding on XY22. In contrast, there were 18 DEGs related to detoxifying metabolism, namely eight UDP-glucuronosyltransferases, six cytochromes P450 monooxygenases, one glutathione S-transferase, two ATP-binding cassette transporters, and one major facilitator superfamily transporter;12 of these were upregulated in the aphids feeding on XY22. Our results indicated that both the quantity and quality of phloem nutrition available to aphids are critical for the growth and development of aphids, and the higher resistance of XY22 is mainly due to the reduction in phloem sap ingested by aphids, rather than toxic metabolites.展开更多
Two-dimensional materials are a promising solution for next-generation electronic and optoelectronic devices due to their unique properties.Owing to the atomic thickness of 2D materials,the light-matter interaction le...Two-dimensional materials are a promising solution for next-generation electronic and optoelectronic devices due to their unique properties.Owing to the atomic thickness of 2D materials,the light-matter interaction length in 2D materials is much shorter than that in bulk materials,which limits the performance of optoelectronic devices composed of 2D materials.To improve the light-matter interactions,optical micro/nano architectures have been introduced into 2D material optoelectronic devices.In this review,we present a concise introduction and discussion of various strategies for the enhancement of lightmatter interaction in 2D materials,namely,the plasmonic effect,waveguide,optical cavity,and reflection architecture.We have outlined the current advances in high-performance 2D material optoelectronic devices(eg,photodetectors,electrooptic modulators,light-emitting diodes,and molecular sensors)assisted by these enhancement strategies.Finally,we have discussed the future challenges and opportunities of micro/nano photonic structure designs in 2D material devices.展开更多
A coordinated interaction between osteogenesis and osteoimmune microenvironment is essential for successful bone healing.In particular,macrophages play a central regulatory role in all stages of bone repair.Depending ...A coordinated interaction between osteogenesis and osteoimmune microenvironment is essential for successful bone healing.In particular,macrophages play a central regulatory role in all stages of bone repair.Depending on the signals they sense,these highly plastic cells can mediate the host immune response against the exterior signals of molecular stimuli and implanted scaffolds,to exert regenerative potency to a varying extent.In this article,we first encapsulate the immunomodulatory functions of macrophages during bone regeneration into three aspects,as sweeper,mediator and instructor.We introduce the phagocytic role of macrophages in different bone healing periods(‘sweeper’)and overview a variety of paracrine cytokines released by macrophages either mediating cell mobilisation,vascularisation and matrix remodelling(‘mediator’),or directly driving the osteogenic differentiation of bone progenitors and bone repair(‘instructor’).Then,we systematically classify and discuss the emerging engineering strategies to recruit,activate and modulate the phenotype transition of macrophages,to exploit the power of endogenous macrophages to enhance the performance of engineered bone tissue.展开更多
Uric acid(UA)detection is essential in diagnosis of arthritis,preeclampsia,renal disorder,and cardiovascular diseases,but it is very challenging to realize the required wide detection range and low detection limit.We ...Uric acid(UA)detection is essential in diagnosis of arthritis,preeclampsia,renal disorder,and cardiovascular diseases,but it is very challenging to realize the required wide detection range and low detection limit.We present here a single-atom catalyst consisting of Co(Ⅱ)atoms coordinated by an average of 3.4 N atoms on an N-doped graphene matrix(A-Co-NG)to build an electrochemical biomimetic sensor for UA detection.The A-Co-NG sensor achieves a wide detection range over 0.4-41,950μM and an extremely low detection limit of 33.3±0.024 nM,which are much better than previously reported sensors based on various nanostructured materials.Besides,the A-Co-NG sensor also demonstrates its accurate serum diagnosis for UA for its practical application.Combination of experimental and theoretical calculation discovers that the catalytic process of the A-Co-NG toward UA starts from the oxidation of Co species to form a Co^3+-OH-UA*,followed by the generation of Co^3+-OH+^*UA_H,eventually leading to N-H bond dissociation for the formation of oxidized UA molecule and reduction of oxidized Co^3+to Co^2+for the regenerated A-Co-NG.This work provides a promising material to realize UA detection with wide detection range and low detection limit to meet the practical diagnosis requirements,and the proposed sensing mechanism sheds light on fundamental insights for guiding exploration of other biosensing processes.展开更多
Acute central nervous system injuries are among the most common causes of disability worldwide,with widespread social and economic implications.Motor tract injury accounts for the majority of this disability;therefore...Acute central nervous system injuries are among the most common causes of disability worldwide,with widespread social and economic implications.Motor tract injury accounts for the majority of this disability;therefore,there is impetus to understand mechanisms underlying the pathophysiology of injury and subsequent reorganization of the motor tract that may lead to recovery.After acute central nervous system injury,there are changes in the microenvironment and structure of the motor tract.For example,ischemic stroke involves decreased local blood flow and tissue death from lack of oxygen and nutrients.Traumatic injury,in contrast,causes stretching and shearing injury to microstructures,including myelinated axons and their surrounding vessels.Both involve blood-brain barrier dysfunction,which is an important initial event.After acute central nervous system injury,motor tract reorganization occurs in the form of cortical remapping in the gray matter and axonal regeneration and rewiring in the white matter.Cortical remapping involves one cortical region taking on the role of another.cAMP-response-element binding protein is a key transcription factor that can enhance plasticity in the peri-infarct cortex.Axonal regeneration and rewiring depend on complex cell-cell interactions between axons,oligodendrocytes,and other cells.The RhoA/Rho-associated coiled-coil containing kinase signaling pathway plays a central role in axon growth/regeneration through interactions with myelin-derived axonal growth inhibitors and regulation of actin cytoskeletal dynamics.Oligodendrocytes and their precursors play a role in myelination,and neurons are involved through their voltage-gated calcium channels.Understanding the pathophysiology of injury and the biology of motor tract reorganization may allow the development of therapies to enhance recovery after acute central nervous system injury.These include targeted rehabilitation,novel pharmacotherapies,such as growth factors and axonal growth inhibitor blockade,and the implementation of n展开更多
This paper presents an efficient numerical tool for the prediction of railway dynamic response.A behavior calibration of the infinite Euler-Bernoulli beam resting on continuous viscoelastic foundation is proposed.Cons...This paper presents an efficient numerical tool for the prediction of railway dynamic response.A behavior calibration of the infinite Euler-Bernoulli beam resting on continuous viscoelastic foundation is proposed.Constitutive laws of the discrete elements are determined for a rectilinear ballasted track.A three-dimensional model coupled with an adaptive meshing scheme is employed to calibrate the beam model impedances by finding the similarity between the output signals using the genetic algorithm.The model shows an important performance with significant reduction in computational effort.This study emphasizes the major impact of the excitation characteristics on the parameters of the discrete models.展开更多
A new formula for the concentration profile of nonuniform sediment is derived using the diffusion differential equation with equilibrium bed concentration.The interaction coefficient for nonuniform sediment particles ...A new formula for the concentration profile of nonuniform sediment is derived using the diffusion differential equation with equilibrium bed concentration.The interaction coefficient for nonuniform sediment particles as a function of both relative diameter and geometric standard deviation of nonuniform sediment is taken into account in the settling velocity.The diffusion coefficient is obtained from the logarithmic velocity profile.This new formula possesses several advantages as follows:(1)avoids theoretical defect of the Rouse formula,which states that the sediment concentration is infinite at the bottom and zero at the water surface.(2)suitable for an arbitrary fraction of nonuniform sediment,and(3)easy to apply with a simple form.The formula yields less difference among concentration profiles for various particles than that for uniform sediment and reveals the lawfor fractional concentration distribution of nonuniform sediment.The calculated concentration agrees well with the measured data from the Yangtze River.展开更多
Proteomic approaches are currently used to explore and identify interacting partners of proteins involved in diverse biological processes or with therapeutic potential.The cannabinoid receptor 1,CB_1,is the main media...Proteomic approaches are currently used to explore and identify interacting partners of proteins involved in diverse biological processes or with therapeutic potential.The cannabinoid receptor 1,CB_1,is the main mediator of cannabinoids effects in the central nervous system.The role of the endocannabinoid system in development and physiology and as a target of pharmacological and cellular therapies is the subject of intense research.Therefore。展开更多
Ischemic stroke is a complicated disease, and its pathogenesis has been attributed to the occurrence of genetic polymorphisms.Evidence has suggested that the microRNA let-7a is involved in the pathogenesis of ischemic...Ischemic stroke is a complicated disease, and its pathogenesis has been attributed to the occurrence of genetic polymorphisms.Evidence has suggested that the microRNA let-7a is involved in the pathogenesis of ischemic stroke.Pri-miRNA is the primary transcript, which undergoes several processing steps to generate pre-miRNA and, later, mature miRNAs.In this case-control study, we analyzed the distribution of prilet-7a-2 variants in patients at a high risk for ischemic stroke and the interactions of pri-let-7a-2 variants and environmental factors.Blood samples and clinical information were collected from 1086 patients with ischemic stroke and 836 healthy controls between December 2013 and December 2015 at the First Affiliated Hospital of China Medical University.We found that the rs1143770 CC genotype and the C allele were associated with a decreased risk of ischemic stroke, whereas the rs629367 CC genotype was associated with an increased risk for ischemic stroke.Moreover, these two single-nucleotide polymorphisms were in linkage disequilibrium in this study sample.We analyzed gene-environment interactions and found that rs1143770 exerted a combined effect on the pathogenesis of ischemic stroke, together with alcohol use, smoking, and a history of hypertension.Therefore, the detection of pri-let-7a-2 polymorphisms may increase the awareness of ischemic stroke risk.This study was approved by the Institutional Ethics Committee of the First Affiliated Hospital of China Medical University, China(approval No.2012-38-1) on February 20, 2012, and was registered with the Chinese Clinical Trial Registry(registration number: ChiCTR-COC-17013559) on December 27, 2017.展开更多
Microglia are brain-resident immune cells that contribute to the maintenance of brain homeostasis.In the epileptic brain, microglia show various activation phenotypes depending on the stage of epileptogenesis.Therefor...Microglia are brain-resident immune cells that contribute to the maintenance of brain homeostasis.In the epileptic brain, microglia show various activation phenotypes depending on the stage of epileptogenesis.Therefore, it remains unclear whether microglial activation acts in a pro-epileptic or anti-epileptic manner.In mesial temporal lobe epilepsy, one of the most common form of epilepsies, microglia exhibit at least two distinct morphologies, amoeboid shape and ramified shape.Amoeboid microglia are often found in sclerotic area, whereas ramified microglia are mainly found in non-sclerotic area;however, it remains unclear whether these structurally distinct microglia share separate roles in the epileptic brain.Here, we review the roles of the two distinct microglial phenotypes, focusing on their pro-and anti-epileptic roles in terms of inflammatory response, regulation of neurogenesis and microglia-neuron interaction.展开更多
The cell differentiation in multicellular eukaryotes is one of the most curious phenomena. The recent gene and genome sequencing reveals that most of differentiated cells in a multicellular eukaryote carry a common ge...The cell differentiation in multicellular eukaryotes is one of the most curious phenomena. The recent gene and genome sequencing reveals that most of differentiated cells in a multicellular eukaryote carry a common genome and that such a genome contains the expanded repertoire of genes of proteins associated with the cell-cell adhesion, intercellular and intracellular signal transduction and transcriptional regulation. The cell differentiation occurs in the assembly consisting of a large number of cells after the cell proliferation, and this process is regarded as a stochastic process. Its formulation starts with the master equation in the present paper. The cell differentiation is reproduced in the equation of the most probable path derived from the master equation, when the short-range and long-range interactions between the cells as well as the transition probability between the proliferation and differentiation modes are considered. Moreover, the equation of the most probable path explains the experimental results such as the “memory”, tissue culture and the preparation of induced pluripotent stem (iPS) cells in embryology, if the long-range interaction is considered to be the regulation of gene transcription under the influence of intracellular signal transduction from the receptor accepting the ligand secreted by other types of cells and the short-range interaction is considered to stabilize the intracellular signal transduction by the contact between the same type of cells. The “organizer” found in the initial development of embryo is also explained as the cells that preferentially express the specific gene of a ligand to rouse the long-range interaction. In conclusion, the present study proposes that the complicated intercellular and intracellular signal transduction causing the cell differentiation is ascribed to the long-range interaction between distinctive types of cells and the short-range interaction between the same type of cells.展开更多
Sorghum [<i><span style="font-family:Verdana;">Sorghum bicolor</span></i><span style="font-family:Verdana;"> (L.) Moench] is a high-yielding, nutrient-use efficient, a...Sorghum [<i><span style="font-family:Verdana;">Sorghum bicolor</span></i><span style="font-family:Verdana;"> (L.) Moench] is a high-yielding, nutrient-use efficient, and drought tolerant crop that can be cultivated on over 80 per cent of the world’s agricultural land. However, a number of biotic and abiotic factors are limiting grain yield increase. Diseases (leaf and grain) are considered as one of the major biotic factors hindering sorghum productivity in the highland and intermediate altitude sorghum growing areas of Ethiopia. In addition, the yield performance of crop varieties is highly influenced by genotype × environment (G × E) interaction which is the major focus of researchers while generating improved varieties. In Ethiopia, high yielding and stable varieties that withstand biotic stress in the highland areas are limited. In line with this, the yield performance of 21 sorghum genotypes and one standard check were evaluated across 14 environments with the objectives of estimating magnitude G </span><span style="font-family:Verdana;">× E interaction for grain yield and to identify high yielder and stable genotypes across environments. The experiment was laid out using Randomized Complete Block Design with three replications in all environments. The combined analysis of variance across environments revealed highly significant differences among environments, genotypes and G × E interactions of grain yield suggesting further analysis of the G × E interaction. The results of the combined AMMI analysis of variance indicated that the total variation in grain yield was attributed to environments effects 71.21%, genotypes effects 4.52% and G × E interactions effects 24.27% indicating the major sources of variation. Genotypes 2006AN7010 and 2006AN7011 were high yielder and they were stable across environments and one variety has been released for commercial production and can be used as parental lines for genetic improvement in the sorghum improvement program. In general, this research study revealed the 展开更多
Complex flow around floating structures is a highly nonlinear problem,and it is a typical feature in ship and ocean engineering.Traditional experimental methods and potential flow theory have limitations in predicting...Complex flow around floating structures is a highly nonlinear problem,and it is a typical feature in ship and ocean engineering.Traditional experimental methods and potential flow theory have limitations in predicting complex viscous flows.With the improvement of high-performance computing and the development of numerical techniques,computational fluid dynamics(CFD)has become increasingly powerful in predicting the complex viscous flow around floating structures.This paper reviews the recent progress in CFD techniques for numerical solutions of typical complex viscous flows in ship and ocean engineering.Applications to free-surface flows,breaking bow waves of high-speed ship,ship hull-propeller-rudder interaction,vortexinduced vibration of risers,vortex-induced motions of deep-draft platforms,and floating offshore wind turbines are discussed.Typical techniques,including volume of fluid for sharp interface,dynamic overset grid,detached eddy simulation,and fluid-structure coupling,are reviewed along with their applications.Some novel techniques,such as high-efficiency Cartesian grid method and GPU acceleration technique,are discussed in the last part as the future perspective for further enhancement of accuracy and efficiency for CFD simulations of complex flow in ship and ocean engineering.展开更多
Calculation results of the Monte Carlo method of the average energy of the electrostatic interaction between the quarks are presented to the neutron and proton. The proposed model of the distribution of quarks in prot...Calculation results of the Monte Carlo method of the average energy of the electrostatic interaction between the quarks are presented to the neutron and proton. The proposed model of the distribution of quarks in protons and neutrons is possible to assess the area which included a strong (gluon) interaction. Given the fact that the probability of finding a quark in the field with strong interaction is less than one, there is a good agreement between the experimental and calculated values of the mass difference between the neutron and the proton.展开更多
基金supported by the National Natural Science Foundation of China(No.51879291)。
文摘The complex micro-interfacial interaction theories of heavy metal ions such as Pb(Ⅱ)and Cd(Ⅱ)adsorption on fine sediment in aqueous solution were not systematically investigated.The aim of this work was to reflect the micro-interfacial adsorption characteristics.Sediment samples were collected from an estuary.The Isothermal and kinetics adsorption experiment were done to acquire the data.Isothermal,kinetics,film diffusion and intraparticle diffusion models were adopted to fit the adsorption experimental data.The results indicated that the Langmuir,Freundlich and Temkin models were suitable for analyzing the isothermal experimental data.The maximum adsorption capacities of Pb(Ⅱ)and Cd(Ⅱ)on the sediment were 1.1377 and 0.9821 mg·g-1,respectively.The qm and KL of the Langmuir model,Kf and nF of the Freundlich model,and b and A of the Temkin model all exhibited a power function relationship with the initial adsorbate concentration.The pseudo-second-order model provided a better fit for the experimental kinetics data compared with the fit of the pseudo-first-order and Elovich models.The pseudo-second-order parameters k2 and qe of Pb(Ⅱ)and qe of Cd(Ⅱ)both had a power function relationship with adsorption time,additionally,the k2 of Cd(Ⅱ)had an exponential function relationship with adsorption time.The liquid-film diffusion parameters kfd of Pb(Ⅱ)and Cd(Ⅱ)were 0.0569 and 0.1806 min1,respectively.The intraparticle diffusion parameter kid values of Pb(Ⅱ)and Cd(Ⅱ)were 0.0055 mg$g1$min1/2 and 0.0049 mg$g1$min1/2,respectively.The physical significance of the model parameters showed that Pb(Ⅱ)adsorption on sediment was stronger than Cd(Ⅱ).The results of this study provided a theoretical reference for the micro-interfacial mechanism of heavy metal ion adsorption on sediment.
基金supported by the National Natural Science Foundation of China (31272089)。
文摘Plant resistance against insects mainly depends on nutrient restriction and toxic metabolites, but the relative importance of nutrition and toxins remains elusive. We examined performance, nutrition ingestion, and transcriptome response of the English grain aphid, Sitobion avenae, feeding on resistant Xiaoyan 22(XY22) and susceptible Xinong 979(XN979) wheat cultivars. Aphids had lower body weight and fecundity when feeding on XY22 than on XN979, although the phloem sap of XY22 had a higher nutritive quality(in terms of amino acid:sucrose ratio). Aphids feeding on XY22 also had a lower honeydew excretion rate than those on XN979, suggesting that aphids ingested less phloem sap from XY22. The transcriptome data showed 600 differentially expressed genes(DEGs), and 11 of the top 20 KEGG pathways significantly enriched in DEGs were involved in nutrient metabolism. We found 81 DEGs associated with the metabolism of sugars, lipids, and amino acids, 59 of which were significantly downregulated in aphids feeding on XY22. In contrast, there were 18 DEGs related to detoxifying metabolism, namely eight UDP-glucuronosyltransferases, six cytochromes P450 monooxygenases, one glutathione S-transferase, two ATP-binding cassette transporters, and one major facilitator superfamily transporter;12 of these were upregulated in the aphids feeding on XY22. Our results indicated that both the quantity and quality of phloem nutrition available to aphids are critical for the growth and development of aphids, and the higher resistance of XY22 is mainly due to the reduction in phloem sap ingested by aphids, rather than toxic metabolites.
基金Innovation and Technology Commission,Grant/Award Number:ITS/390/18Research Grants Council,University Grants Committee,Grant/Award Numbers:14203018,14204616,AoE/P-02/12,N_CUHK438/18。
文摘Two-dimensional materials are a promising solution for next-generation electronic and optoelectronic devices due to their unique properties.Owing to the atomic thickness of 2D materials,the light-matter interaction length in 2D materials is much shorter than that in bulk materials,which limits the performance of optoelectronic devices composed of 2D materials.To improve the light-matter interactions,optical micro/nano architectures have been introduced into 2D material optoelectronic devices.In this review,we present a concise introduction and discussion of various strategies for the enhancement of lightmatter interaction in 2D materials,namely,the plasmonic effect,waveguide,optical cavity,and reflection architecture.We have outlined the current advances in high-performance 2D material optoelectronic devices(eg,photodetectors,electrooptic modulators,light-emitting diodes,and molecular sensors)assisted by these enhancement strategies.Finally,we have discussed the future challenges and opportunities of micro/nano photonic structure designs in 2D material devices.
基金the funding grants from Fundo para o Desenvolvimento das Ciencias e da Tecnologia,Macau SAR(0018/2019/AFJ)the University of Macau(MYRG2019-00080-ICMS).
文摘A coordinated interaction between osteogenesis and osteoimmune microenvironment is essential for successful bone healing.In particular,macrophages play a central regulatory role in all stages of bone repair.Depending on the signals they sense,these highly plastic cells can mediate the host immune response against the exterior signals of molecular stimuli and implanted scaffolds,to exert regenerative potency to a varying extent.In this article,we first encapsulate the immunomodulatory functions of macrophages during bone regeneration into three aspects,as sweeper,mediator and instructor.We introduce the phagocytic role of macrophages in different bone healing periods(‘sweeper’)and overview a variety of paracrine cytokines released by macrophages either mediating cell mobilisation,vascularisation and matrix remodelling(‘mediator’),or directly driving the osteogenic differentiation of bone progenitors and bone repair(‘instructor’).Then,we systematically classify and discuss the emerging engineering strategies to recruit,activate and modulate the phenotype transition of macrophages,to exploit the power of endogenous macrophages to enhance the performance of engineered bone tissue.
基金the National Natural Science Foundation of China(Nos.22075195,21705115,21972102,and 21775122)the Natural Science Foundation of Jiangsu Province of China(BK20170378)+1 种基金Jiangsu Specially Appointed Professor program,the Natural Science research Foundation of Jiangsu Higher Education Institutions(17KJB150036)the Jiangsu Laboratory for Biochemical Sensing and Biochip.Natural Science Foundation of Chongqing(cstc2018jcyjAX0693),China.
文摘Uric acid(UA)detection is essential in diagnosis of arthritis,preeclampsia,renal disorder,and cardiovascular diseases,but it is very challenging to realize the required wide detection range and low detection limit.We present here a single-atom catalyst consisting of Co(Ⅱ)atoms coordinated by an average of 3.4 N atoms on an N-doped graphene matrix(A-Co-NG)to build an electrochemical biomimetic sensor for UA detection.The A-Co-NG sensor achieves a wide detection range over 0.4-41,950μM and an extremely low detection limit of 33.3±0.024 nM,which are much better than previously reported sensors based on various nanostructured materials.Besides,the A-Co-NG sensor also demonstrates its accurate serum diagnosis for UA for its practical application.Combination of experimental and theoretical calculation discovers that the catalytic process of the A-Co-NG toward UA starts from the oxidation of Co species to form a Co^3+-OH-UA*,followed by the generation of Co^3+-OH+^*UA_H,eventually leading to N-H bond dissociation for the formation of oxidized UA molecule and reduction of oxidized Co^3+to Co^2+for the regenerated A-Co-NG.This work provides a promising material to realize UA detection with wide detection range and low detection limit to meet the practical diagnosis requirements,and the proposed sensing mechanism sheds light on fundamental insights for guiding exploration of other biosensing processes.
基金supported in part by JSPS“KAKENHI”Grant-in-Aid for Early-Career Scientists,Grant No.18K16566(to HT)Research Abroad from the Japan Brain Foundation(to HT)+2 种基金Mochida Memorial Foundation for Medical and Pharmaceutical Research of Japan(to HT)the Rotary Foundation Global Scholarship Grants,Grant Nos.GG1759314,GG1876795)(to HT)the National Institute of Neurological Disorders and Stroke of USA,No.R25 NS065743(to RWR).
文摘Acute central nervous system injuries are among the most common causes of disability worldwide,with widespread social and economic implications.Motor tract injury accounts for the majority of this disability;therefore,there is impetus to understand mechanisms underlying the pathophysiology of injury and subsequent reorganization of the motor tract that may lead to recovery.After acute central nervous system injury,there are changes in the microenvironment and structure of the motor tract.For example,ischemic stroke involves decreased local blood flow and tissue death from lack of oxygen and nutrients.Traumatic injury,in contrast,causes stretching and shearing injury to microstructures,including myelinated axons and their surrounding vessels.Both involve blood-brain barrier dysfunction,which is an important initial event.After acute central nervous system injury,motor tract reorganization occurs in the form of cortical remapping in the gray matter and axonal regeneration and rewiring in the white matter.Cortical remapping involves one cortical region taking on the role of another.cAMP-response-element binding protein is a key transcription factor that can enhance plasticity in the peri-infarct cortex.Axonal regeneration and rewiring depend on complex cell-cell interactions between axons,oligodendrocytes,and other cells.The RhoA/Rho-associated coiled-coil containing kinase signaling pathway plays a central role in axon growth/regeneration through interactions with myelin-derived axonal growth inhibitors and regulation of actin cytoskeletal dynamics.Oligodendrocytes and their precursors play a role in myelination,and neurons are involved through their voltage-gated calcium channels.Understanding the pathophysiology of injury and the biology of motor tract reorganization may allow the development of therapies to enhance recovery after acute central nervous system injury.These include targeted rehabilitation,novel pharmacotherapies,such as growth factors and axonal growth inhibitor blockade,and the implementation of n
文摘This paper presents an efficient numerical tool for the prediction of railway dynamic response.A behavior calibration of the infinite Euler-Bernoulli beam resting on continuous viscoelastic foundation is proposed.Constitutive laws of the discrete elements are determined for a rectilinear ballasted track.A three-dimensional model coupled with an adaptive meshing scheme is employed to calibrate the beam model impedances by finding the similarity between the output signals using the genetic algorithm.The model shows an important performance with significant reduction in computational effort.This study emphasizes the major impact of the excitation characteristics on the parameters of the discrete models.
基金The current research was supported by the National Key Research and Development Program(Grant No.2016YFC0402305-02)the National Natural Science Foundation of China(Grant No.91647209).
文摘A new formula for the concentration profile of nonuniform sediment is derived using the diffusion differential equation with equilibrium bed concentration.The interaction coefficient for nonuniform sediment particles as a function of both relative diameter and geometric standard deviation of nonuniform sediment is taken into account in the settling velocity.The diffusion coefficient is obtained from the logarithmic velocity profile.This new formula possesses several advantages as follows:(1)avoids theoretical defect of the Rouse formula,which states that the sediment concentration is infinite at the bottom and zero at the water surface.(2)suitable for an arbitrary fraction of nonuniform sediment,and(3)easy to apply with a simple form.The formula yields less difference among concentration profiles for various particles than that for uniform sediment and reveals the lawfor fractional concentration distribution of nonuniform sediment.The calculated concentration agrees well with the measured data from the Yangtze River.
基金funded by the Ministry of Science,Innovation and Universities of Spain,Grant ID SAF2015-69927 (cofunded by FEDER-European Union)(to EMH)。
文摘Proteomic approaches are currently used to explore and identify interacting partners of proteins involved in diverse biological processes or with therapeutic potential.The cannabinoid receptor 1,CB_1,is the main mediator of cannabinoids effects in the central nervous system.The role of the endocannabinoid system in development and physiology and as a target of pharmacological and cellular therapies is the subject of intense research.Therefore。
基金supported by the National Natural Science Foundation of China, No.81901189the Natural Science Foundation of Liaoning Province of China, No.2019-BS-147(both to YZW)。
文摘Ischemic stroke is a complicated disease, and its pathogenesis has been attributed to the occurrence of genetic polymorphisms.Evidence has suggested that the microRNA let-7a is involved in the pathogenesis of ischemic stroke.Pri-miRNA is the primary transcript, which undergoes several processing steps to generate pre-miRNA and, later, mature miRNAs.In this case-control study, we analyzed the distribution of prilet-7a-2 variants in patients at a high risk for ischemic stroke and the interactions of pri-let-7a-2 variants and environmental factors.Blood samples and clinical information were collected from 1086 patients with ischemic stroke and 836 healthy controls between December 2013 and December 2015 at the First Affiliated Hospital of China Medical University.We found that the rs1143770 CC genotype and the C allele were associated with a decreased risk of ischemic stroke, whereas the rs629367 CC genotype was associated with an increased risk for ischemic stroke.Moreover, these two single-nucleotide polymorphisms were in linkage disequilibrium in this study sample.We analyzed gene-environment interactions and found that rs1143770 exerted a combined effect on the pathogenesis of ischemic stroke, together with alcohol use, smoking, and a history of hypertension.Therefore, the detection of pri-let-7a-2 polymorphisms may increase the awareness of ischemic stroke risk.This study was approved by the Institutional Ethics Committee of the First Affiliated Hospital of China Medical University, China(approval No.2012-38-1) on February 20, 2012, and was registered with the Chinese Clinical Trial Registry(registration number: ChiCTR-COC-17013559) on December 27, 2017.
基金supported in part by a Grant-in-Aid for Scientific Research (B)(17H03988 to RK) from JSPS and JST PRESTO (JPMJPR18H4 to RK)。
文摘Microglia are brain-resident immune cells that contribute to the maintenance of brain homeostasis.In the epileptic brain, microglia show various activation phenotypes depending on the stage of epileptogenesis.Therefore, it remains unclear whether microglial activation acts in a pro-epileptic or anti-epileptic manner.In mesial temporal lobe epilepsy, one of the most common form of epilepsies, microglia exhibit at least two distinct morphologies, amoeboid shape and ramified shape.Amoeboid microglia are often found in sclerotic area, whereas ramified microglia are mainly found in non-sclerotic area;however, it remains unclear whether these structurally distinct microglia share separate roles in the epileptic brain.Here, we review the roles of the two distinct microglial phenotypes, focusing on their pro-and anti-epileptic roles in terms of inflammatory response, regulation of neurogenesis and microglia-neuron interaction.
文摘The cell differentiation in multicellular eukaryotes is one of the most curious phenomena. The recent gene and genome sequencing reveals that most of differentiated cells in a multicellular eukaryote carry a common genome and that such a genome contains the expanded repertoire of genes of proteins associated with the cell-cell adhesion, intercellular and intracellular signal transduction and transcriptional regulation. The cell differentiation occurs in the assembly consisting of a large number of cells after the cell proliferation, and this process is regarded as a stochastic process. Its formulation starts with the master equation in the present paper. The cell differentiation is reproduced in the equation of the most probable path derived from the master equation, when the short-range and long-range interactions between the cells as well as the transition probability between the proliferation and differentiation modes are considered. Moreover, the equation of the most probable path explains the experimental results such as the “memory”, tissue culture and the preparation of induced pluripotent stem (iPS) cells in embryology, if the long-range interaction is considered to be the regulation of gene transcription under the influence of intracellular signal transduction from the receptor accepting the ligand secreted by other types of cells and the short-range interaction is considered to stabilize the intracellular signal transduction by the contact between the same type of cells. The “organizer” found in the initial development of embryo is also explained as the cells that preferentially express the specific gene of a ligand to rouse the long-range interaction. In conclusion, the present study proposes that the complicated intercellular and intracellular signal transduction causing the cell differentiation is ascribed to the long-range interaction between distinctive types of cells and the short-range interaction between the same type of cells.
文摘Sorghum [<i><span style="font-family:Verdana;">Sorghum bicolor</span></i><span style="font-family:Verdana;"> (L.) Moench] is a high-yielding, nutrient-use efficient, and drought tolerant crop that can be cultivated on over 80 per cent of the world’s agricultural land. However, a number of biotic and abiotic factors are limiting grain yield increase. Diseases (leaf and grain) are considered as one of the major biotic factors hindering sorghum productivity in the highland and intermediate altitude sorghum growing areas of Ethiopia. In addition, the yield performance of crop varieties is highly influenced by genotype × environment (G × E) interaction which is the major focus of researchers while generating improved varieties. In Ethiopia, high yielding and stable varieties that withstand biotic stress in the highland areas are limited. In line with this, the yield performance of 21 sorghum genotypes and one standard check were evaluated across 14 environments with the objectives of estimating magnitude G </span><span style="font-family:Verdana;">× E interaction for grain yield and to identify high yielder and stable genotypes across environments. The experiment was laid out using Randomized Complete Block Design with three replications in all environments. The combined analysis of variance across environments revealed highly significant differences among environments, genotypes and G × E interactions of grain yield suggesting further analysis of the G × E interaction. The results of the combined AMMI analysis of variance indicated that the total variation in grain yield was attributed to environments effects 71.21%, genotypes effects 4.52% and G × E interactions effects 24.27% indicating the major sources of variation. Genotypes 2006AN7010 and 2006AN7011 were high yielder and they were stable across environments and one variety has been released for commercial production and can be used as parental lines for genetic improvement in the sorghum improvement program. In general, this research study revealed the
基金supported by the National Natural Science Foundation of China(51809169,51879159)Chang Jiang Scholars Program(T2014099)+2 种基金Shanghai Excellent Academic Leaders Program(17XD1402300)Innovative Special Project of Numerical Tank of Ministry of Industry and Information Technology of China(2016-23/09)National Key Research and Development Program of China(2019YFB1704203,2019YFC0312400).
文摘Complex flow around floating structures is a highly nonlinear problem,and it is a typical feature in ship and ocean engineering.Traditional experimental methods and potential flow theory have limitations in predicting complex viscous flows.With the improvement of high-performance computing and the development of numerical techniques,computational fluid dynamics(CFD)has become increasingly powerful in predicting the complex viscous flow around floating structures.This paper reviews the recent progress in CFD techniques for numerical solutions of typical complex viscous flows in ship and ocean engineering.Applications to free-surface flows,breaking bow waves of high-speed ship,ship hull-propeller-rudder interaction,vortexinduced vibration of risers,vortex-induced motions of deep-draft platforms,and floating offshore wind turbines are discussed.Typical techniques,including volume of fluid for sharp interface,dynamic overset grid,detached eddy simulation,and fluid-structure coupling,are reviewed along with their applications.Some novel techniques,such as high-efficiency Cartesian grid method and GPU acceleration technique,are discussed in the last part as the future perspective for further enhancement of accuracy and efficiency for CFD simulations of complex flow in ship and ocean engineering.
文摘Calculation results of the Monte Carlo method of the average energy of the electrostatic interaction between the quarks are presented to the neutron and proton. The proposed model of the distribution of quarks in protons and neutrons is possible to assess the area which included a strong (gluon) interaction. Given the fact that the probability of finding a quark in the field with strong interaction is less than one, there is a good agreement between the experimental and calculated values of the mass difference between the neutron and the proton.