The 12 May 2008 Wenchuan earthquake （Ms=8.0） struck on the Longmen Shan foreland thrust zone. The event took place within the context of long-term uplift of the Longmen Shan range as a result of the extensive eastwa...The 12 May 2008 Wenchuan earthquake （Ms=8.0） struck on the Longmen Shan foreland thrust zone. The event took place within the context of long-term uplift of the Longmen Shan range as a result of the extensive eastward-extrusion of crustal materials from the Tibetan plateau against the rheologically strong crust of the Sichuan Basin. The Longmen Shan range is charac- terized by a Pre-Sinian crystalline complex constrained by the Maoxian-Wenchuan-Kangding ductile detach- ment at the western margin and the Yingxiu-Beichuan- Luding ductile thrust at the eastern margin. The Long- men Shan uplift was initiated by intracontinental sub- duction between the Songpan-Ganzi terrane and the Yangtze block during the Pre-Cenozoic. The uplift rate was increased considerably by the collision between the Indian and Eurasian plates since -50 Ma. The Wenchuan earthquake resulted in two major NE-strik- ing coseismic ruptures （i.e., the -275 km long Yingxiu- Beichuan-Qingchuan fault and the -100 km long Anx- ian-Guanxian fault）. Field investigations combined with focal solutions and seismic reflection profiles suggest that the coseismic ruptures are steeply dipping close-to- pure reverse or right reverse oblique slip faults in the -15 km thick upper crust. These faults are unfavorably oriented for frictional slip in the horizontally compres- sional regime, so that they need a long recurrence interval to accumulate the tectonic stress and fluid pres- sure to critically high levels for the formation of strong earthquakes at a given locality. It is also found that all the large earthquakes （Ms〉7.0） occurred in the fault zones across which the horizontal movement velocities measured by the GPS are markedly low （〈3 mm/yr）. The faults, which constitute the northeastern fronts of the enlarging Tibetan plateau against the strong Sichuan Basin, Ala Shan and Ordos blocks, are very destructive, although their average recurrence intervals are generally long.展开更多
Since the outbreak of 2019 novel coronavirus infection (2019-nCoV) in Wuhan City,China,by January 30,2020,a total of 9692 confirmed cases and 15,238 suspected cases have been reported around 31 provinces or cities in ...Since the outbreak of 2019 novel coronavirus infection (2019-nCoV) in Wuhan City,China,by January 30,2020,a total of 9692 confirmed cases and 15,238 suspected cases have been reported around 31 provinces or cities in China.Among the confirmed cases,1527 were severe cases,171 had recovered and been discharged at home,and 213 died.And among these cases,a total of 28 children aged from 1 month to 17 years have been reported in China.For standardizing prevention and management of 2019-nCoV infections in children,we called up an experts' committee to formulate this experts' consensus statement.This statement is based on the Novel Coronavirus Infection Pneumonia Diagnosis and Treatment Standards (the fourth edition) (National Health Committee) and other previous diagnosis and treatment strategies for pediatric virus infections.The present consensus statement summarizes current strategies on diagnosis,treatment,and prevention of 2019-nCoV infection in children.展开更多
B cells are generally considered to be positive regulators of the immune response because of their capability to produce antibodies, including autoantibodies. The production of antibodies facilitates optimal CD4＋ T-c...B cells are generally considered to be positive regulators of the immune response because of their capability to produce antibodies, including autoantibodies. The production of antibodies facilitates optimal CD4＋ T-cell activation because B cells serve as antigen-presenting cells and exert other modulatory functions in immune responses. However, certain B cells can also negatively regulate the immune response by producing regulatory cytokines and directly interacting with pathogenic T cells via cell-to-cell contact. These types of B Cells are defined as regulatory B （Breg） cells. The regulatory function of Breg cells has been demonstrated in mouse models of inflammation, cancer, transplantation, and particularly in autoimmunity. In this review, we focus on the recent advances that lead to the understanding of the development and function of Breg cells and the implications of B cells in human autoimmune diseases.展开更多
TGF-β 1–3 are unique multi-functional growth factors that are only expressed in mammals, and mainly secreted and stored as a latent complex in the extracellular matrix(ECM). The biological functions of TGF-β in adu...TGF-β 1–3 are unique multi-functional growth factors that are only expressed in mammals, and mainly secreted and stored as a latent complex in the extracellular matrix(ECM). The biological functions of TGF-β in adults can only be delivered after ligand activation, mostly in response to environmental perturbations. Although involved in multiple biological and pathological processes of the human body, the exact roles of TGF-β in maintaining stem cells and tissue homeostasis have not been well-documented until recent advances, which delineate their functions in a given context. Our recent findings, along with data reported by others, have clearly shown that temporal and spatial activation of TGF-β is involved in the recruitment of stem/progenitor cell participation in tissue regeneration/remodeling process, whereas sustained abnormalities in TGF-β ligand activation, regardless of genetic or environmental origin, will inevitably disrupt the normal physiology and lead to pathobiology of major diseases. Modulation of TGF-β signaling with different approaches has proven effective pre-clinically in the treatment of multiple pathologies such as sclerosis/fibrosis, tumor metastasis, osteoarthritis, and immune disorders. Thus, further elucidation of the mechanisms by which TGF-β is activated in different tissues/organs and how targeted cells respond in a context-dependent way can likely be translated with clinical benefits in the management of a broad range of diseases with the involvement of TGF-β.展开更多
Postmenopausal osteoporosis （PMO） is a prevalent metabolic bone disease characterized by bone loss and structural destruction, which increases the risk of fracture in postmenopausal women. Owing to the high morbidit...Postmenopausal osteoporosis （PMO） is a prevalent metabolic bone disease characterized by bone loss and structural destruction, which increases the risk of fracture in postmenopausal women. Owing to the high morbidity and serious complications of PMO, many efforts have been devoted to its prophylaxis and treatment. The intestinal microbiota is the complex community of microorganisms colonizing the gastrointestinal tract. Probiotics, which are dietary or medical supplements consisting of beneficial intestinal bacteria, work in concert with endogenous intestinal microorganisms to maintain host health. Recent studies have revealed that bone loss in PMO is closely related to host immunity, which is influenced by the intestinal microbiota. The curative effects of probiotics on metabolic bone diseases have also been demonstrated. The effects of the intestinal microbiota on bone metabolism suggest a promising target for PMO management. This review seeks to summarize the critical effects of the intestinal microbiota and probiotics on PMO, with a focus on the molecular mechanisms underlying the pathogenic relationship between bacteria and host, and to define the possible treatment options.展开更多
Bimetallic Fe-Co/GAC （granular activated carbon） was prepared and used as heterogeneous catalyst in the ultrasound enhanced heterogeneous activation of peroxydisulfate （PS, S2O8 2-） process. The effect of initial ...Bimetallic Fe-Co/GAC （granular activated carbon） was prepared and used as heterogeneous catalyst in the ultrasound enhanced heterogeneous activation of peroxydisulfate （PS, S2O8 2-） process. The effect of initial pH, PS concentration, catalyst addition and stirring rate on the decolorization of Acid Orange 7 （AO7） was investigated. The results showed that the decolorization efficiency increased with an increase in PS concentration from 0.3 to 0.5 g/L and an increase in catalyst amount from 0.5 to 0.8 g/L. But further increase in PS concentration and catalyst addition would result in an unpronounced increase in decolorization efficiency. In the range of 300 to 900 r/min, stirring rate had little effect on AO7 decolorization. The catalyst stability was evaluated by measuring decolorization efficiency for four successive cycles.展开更多
Spatial-explicitly mapping of the hotspots and coldspots is a vital link in the priority setting for ecosystem services （ES） conservation. However, little research has identified and tested the compactness and effic...Spatial-explicitly mapping of the hotspots and coldspots is a vital link in the priority setting for ecosystem services （ES） conservation. However, little research has identified and tested the compactness and efficiency of their ES hotspots and coldspots, which may weaken the effectiveness of ecological conservation. In this study, based on the RUSLE model and Getis-Ord Gi＊ statistics, we quantified the variation of annual soil conservation services （SC） and identified the statistically significant hotspots and coldspots in Shaanxi Province of China from 2000 to 2013. The results indicate that, 1） areas with high SC presented a significantly increasing trend as well, while areas with low SC only changed slightly; 2） SC hotspots and coldspots showed an obvious spatial differentiation--the hotspots were mainly spatially ag- gregated in southern Shaanxi, while the coldspots were mainly distributed in the Guanzhong Basin and Sand-windy Plateau; and 3） the identified hotspots had the highest capacity of providing SC, with 29.6% of the total area providing 59.7% of the total service. In contrast, the coldspots occupied 46.3% of the total area, but only provided 17.2% of the total SC. In addition to conserving single ES, the Getis-Ord Gi＊ statistics method can also help identify multi-functional priority areas for conserving multiple ES and biodiversity.展开更多
The chemical equilibrium and reaction kinetic behavior in the synthesis of polyoxymethylene dimethyl ethers （DMMn） were investigated over sulfated titania in order to reveal the decisive factor controlling the react...The chemical equilibrium and reaction kinetic behavior in the synthesis of polyoxymethylene dimethyl ethers （DMMn） were investigated over sulfated titania in order to reveal the decisive factor controlling the reaction. The results showed that the molar ratio of adjacent DMMn products in equilibrium solution had the same value, which depended absolutely on the reaction temperature. Meanwhile, the reactions had the same DMMn products distributions under varied reaction conditions. The equilibrium constants of the related step-wise reactions for DMMn formation were equal, which were calculated based on the bulk compositions of the reaction solution. And thus, the selectivity to DMMn was mainly controlled by the chemical equilibrium, i.e., thermodynamic control. In brief, the present results provide some guidance for future synthesis of DMMn.展开更多
Investigation of metal–organic frameworks(MOFs)for biomedical applications has attracted much attention in recent years.MOFs are regarded as a promising class of nanocarriers for drug delivery owing to well-defined s...Investigation of metal–organic frameworks(MOFs)for biomedical applications has attracted much attention in recent years.MOFs are regarded as a promising class of nanocarriers for drug delivery owing to well-defined structure,ultrahigh surface area and porosity,tunable pore size,and easy chemical functionalization.In this review,the unique properties of MOFs and their advantages as nanocarriers for drug delivery in biomedical applications were discussed in the first section.Then,state-ofthe-art strategies to functionalize MOFs with therapeutic agents were summarized,including surface adsorption,pore encapsulation,covalent binding,and functional molecules as building blocks.In the third section,the most recent biological applications of MOFs for intracellular delivery of drugs,proteins,and nucleic acids,especially aptamers,were presented.Finally,challenges and prospects were comprehensively discussed to provide context for future development of MOFs as efficient drug delivery systems.展开更多
A subsurface flow wetland(SSFW)was simulated using a commercial computational fluid dynamic(CFD)code.The constructed media was simulated using porous media and the liquid resident time distribution(RTD)in the SSFW was...A subsurface flow wetland(SSFW)was simulated using a commercial computational fluid dynamic(CFD)code.The constructed media was simulated using porous media and the liquid resident time distribution(RTD)in the SSFW was obtained using the particle trajectory model.The effect of wetland configuration and operating conditions on the hydraulic performance of the SSFW were investigated.The results indicated that the hydraulic performance of the SSFW was predominantly affected by the wetland configuration.The hydr...展开更多
The optimal performance of heat-driven binary separation processes with linear phenomenological heat transfer law(q∝△(T-1)) is analyzed by taking the processes as heat engines which work between high-and low-tempera...The optimal performance of heat-driven binary separation processes with linear phenomenological heat transfer law(q∝△(T-1)) is analyzed by taking the processes as heat engines which work between high-and low-temperature reservoirs and produce enthalpy and energy flows out of the system,and the temperatures of the heat reservoirs are assumed to be time-and space-variables.A numerical method is employed to solve convex optimization problem and Lagrangian function is employed to solve the average optimal control problem.The dimensionless entropy production rate coefficient and dimensionless enthalpy flow rate coefficient are adopted to indicate the major influence factors on the performance of the separation process,such as the properties of different materials and various separation requirements for the separation process.The dimensionless minimum average entropy production rate and dimensionless minimum average heat consumption of the heat-driven binary separation processes are obtained.The obtained results are compared with those obtained with the Newtonian heat transfer law(q∝△(T)).展开更多
Mammalian carboxylesterases(CEs) are key enzymes from the serine hydrolase superfamily.In the human body, two predominant carboxylesterases(CES1 and CES2) have been identified and extensively studied over the past dec...Mammalian carboxylesterases(CEs) are key enzymes from the serine hydrolase superfamily.In the human body, two predominant carboxylesterases(CES1 and CES2) have been identified and extensively studied over the past decade. These two enzymes play crucial roles in the metabolism of a wide variety of endogenous esters, ester-containing drugs and environmental toxicants. The key roles of CES in both human health and xenobiotic metabolism arouse great interest in the discovery of potent CES modulators to regulate endobiotic metabolism or to improve the efficacy of ester drugs. This review covers the structural and catalytic features of CES, tissue distributions, biological functions, genetic polymorphisms, substrate specificities and inhibitor properties of CES1 and CES2, as well as the significance and recent progress on the discovery of CES modulators. The information presented here will help pharmacologists explore the relevance of CES to human diseases or to assign the contribution of certain CES in xenobiotic metabolism. It will also facilitate medicinal chemistry efforts to design prodrugs activated by a given CES isoform, or to develop potent and selective modulators of CES for potential biomedical applications.展开更多
Increased numbers of T follicular helper(Tfh)cells have been implicated in the development of autoimmune diseases including primary Sjögren’s syndrome(pSS),but how the Tfh cell response is regulated during autoi...Increased numbers of T follicular helper(Tfh)cells have been implicated in the development of autoimmune diseases including primary Sjögren’s syndrome(pSS),but how the Tfh cell response is regulated during autoimmune pathogenesis remains largely unclear.Here,we first found negative correlations between IL-10^(+)regulatory B(Breg)cell numbers and Tfh cell responses and disease activity in patients with pSS and mice with experimental Sjögren’s syndrome(ESS).Moreover,we detected high expression of IL-10 receptor on Tfh cells and their precursors in both humans and mice.In culture,IL-10 suppressed human and murine Tfh cell differentiation by promoting STAT5 phosphorylation.By using an adoptive transfer approach and two-photon live imaging,we found significantly increased numbers of Tfh cells with enhanced T cell homing into B cell follicles in the draining cervical lymph nodes of RAG-2−/−mice transferred with IL-10-deficient B cells during ESS development compared with those of RAG-2−/−mice transferred with wild-type B cells.In ESS mice,CD19^(+)CD1d^(hi)CD5^(+)Breg cells with decreased IL-10 production exhibited severely impaired suppressive effects on T cell proliferation.Consistently,CD19^(+)CD24^(+)CD38^(hi) Breg cells from pSS patients showed significantly reduced IL-10 production with defective inhibitory function in the suppression of autologous Tfh cell expansion.Furthermore,the adoptive transfer of IL-10-producing Breg cells markedly suppressed the Tfh cell response and ameliorated ESS progression in ESS mice.Together,these findings demonstrate a critical role for IL-10-producing Breg cells in restraining the effector Tfh cell response during pSS development.展开更多
The Earth–Climate System Model(ECSM)is an important platform for multi-disciplinary and multi-sphere integration research,and its development is at the frontier of international geosciences,especially in the field of...The Earth–Climate System Model(ECSM)is an important platform for multi-disciplinary and multi-sphere integration research,and its development is at the frontier of international geosciences,especially in the field of global change.The research and development(R&D)of ECSM in China began in the 1980 s and have achieved great progress.In China,ECSMs are now mainly developed at the Chinese Academy of Sciences,ministries,and universities.Following a brief review of the development history of Chinese ECSMs,this paper summarized the technical characteristics of nine Chinese ECSMs participating in the Coupled Model Intercomparison Project Phase 6 and preliminarily assessed the basic performances of four Chinese models in simulating the global climate and the climate in East Asia.The projected changes of global precipitation and surface air temperature and the associated relationship with the equilibrium climate sensitivity under four shared socioeconomic path scenarios were also discussed.Finally,combined with the international situation,from the perspective of further improvement,eight directions were proposed for the future development of Chinese ECSMs.展开更多
文摘The 12 May 2008 Wenchuan earthquake （Ms=8.0） struck on the Longmen Shan foreland thrust zone. The event took place within the context of long-term uplift of the Longmen Shan range as a result of the extensive eastward-extrusion of crustal materials from the Tibetan plateau against the rheologically strong crust of the Sichuan Basin. The Longmen Shan range is charac- terized by a Pre-Sinian crystalline complex constrained by the Maoxian-Wenchuan-Kangding ductile detach- ment at the western margin and the Yingxiu-Beichuan- Luding ductile thrust at the eastern margin. The Long- men Shan uplift was initiated by intracontinental sub- duction between the Songpan-Ganzi terrane and the Yangtze block during the Pre-Cenozoic. The uplift rate was increased considerably by the collision between the Indian and Eurasian plates since -50 Ma. The Wenchuan earthquake resulted in two major NE-strik- ing coseismic ruptures （i.e., the -275 km long Yingxiu- Beichuan-Qingchuan fault and the -100 km long Anx- ian-Guanxian fault）. Field investigations combined with focal solutions and seismic reflection profiles suggest that the coseismic ruptures are steeply dipping close-to- pure reverse or right reverse oblique slip faults in the -15 km thick upper crust. These faults are unfavorably oriented for frictional slip in the horizontally compres- sional regime, so that they need a long recurrence interval to accumulate the tectonic stress and fluid pres- sure to critically high levels for the formation of strong earthquakes at a given locality. It is also found that all the large earthquakes （Ms〉7.0） occurred in the fault zones across which the horizontal movement velocities measured by the GPS are markedly low （〈3 mm/yr）. The faults, which constitute the northeastern fronts of the enlarging Tibetan plateau against the strong Sichuan Basin, Ala Shan and Ordos blocks, are very destructive, although their average recurrence intervals are generally long.
文摘Since the outbreak of 2019 novel coronavirus infection (2019-nCoV) in Wuhan City,China,by January 30,2020,a total of 9692 confirmed cases and 15,238 suspected cases have been reported around 31 provinces or cities in China.Among the confirmed cases,1527 were severe cases,171 had recovered and been discharged at home,and 213 died.And among these cases,a total of 28 children aged from 1 month to 17 years have been reported in China.For standardizing prevention and management of 2019-nCoV infections in children,we called up an experts' committee to formulate this experts' consensus statement.This statement is based on the Novel Coronavirus Infection Pneumonia Diagnosis and Treatment Standards (the fourth edition) (National Health Committee) and other previous diagnosis and treatment strategies for pediatric virus infections.The present consensus statement summarizes current strategies on diagnosis,treatment,and prevention of 2019-nCoV infection in children.
文摘B cells are generally considered to be positive regulators of the immune response because of their capability to produce antibodies, including autoantibodies. The production of antibodies facilitates optimal CD4＋ T-cell activation because B cells serve as antigen-presenting cells and exert other modulatory functions in immune responses. However, certain B cells can also negatively regulate the immune response by producing regulatory cytokines and directly interacting with pathogenic T cells via cell-to-cell contact. These types of B Cells are defined as regulatory B （Breg） cells. The regulatory function of Breg cells has been demonstrated in mouse models of inflammation, cancer, transplantation, and particularly in autoimmunity. In this review, we focus on the recent advances that lead to the understanding of the development and function of Breg cells and the implications of B cells in human autoimmune diseases.
基金supported by U.S. National Institutes of Health grants (AR063943 and DK057501 to X.C. AR064833 to J.L.C.)+3 种基金the National Natural Science Foundation of China (81771099 to X.X.)the Key Project for Frontier Research of Science and Technology Department of Sichuan Province (2016JY0006 to X.Z.)Sichuan Province Science and Technology Innovation Team Program (2017TD0016 to Q.Y.).X.X.supported by the visiting scholar fellowship from West China Hospital of Stomatology, Sichuan University
文摘TGF-β 1–3 are unique multi-functional growth factors that are only expressed in mammals, and mainly secreted and stored as a latent complex in the extracellular matrix(ECM). The biological functions of TGF-β in adults can only be delivered after ligand activation, mostly in response to environmental perturbations. Although involved in multiple biological and pathological processes of the human body, the exact roles of TGF-β in maintaining stem cells and tissue homeostasis have not been well-documented until recent advances, which delineate their functions in a given context. Our recent findings, along with data reported by others, have clearly shown that temporal and spatial activation of TGF-β is involved in the recruitment of stem/progenitor cell participation in tissue regeneration/remodeling process, whereas sustained abnormalities in TGF-β ligand activation, regardless of genetic or environmental origin, will inevitably disrupt the normal physiology and lead to pathobiology of major diseases. Modulation of TGF-β signaling with different approaches has proven effective pre-clinically in the treatment of multiple pathologies such as sclerosis/fibrosis, tumor metastasis, osteoarthritis, and immune disorders. Thus, further elucidation of the mechanisms by which TGF-β is activated in different tissues/organs and how targeted cells respond in a context-dependent way can likely be translated with clinical benefits in the management of a broad range of diseases with the involvement of TGF-β.
基金supported by the National Natural Science Foundation of China(grant numbers 81430011,81470711,and 81670978)the Brilliant Young Investigator Award,Sichuan University(grant number 2015SCU04A16)
文摘Postmenopausal osteoporosis （PMO） is a prevalent metabolic bone disease characterized by bone loss and structural destruction, which increases the risk of fracture in postmenopausal women. Owing to the high morbidity and serious complications of PMO, many efforts have been devoted to its prophylaxis and treatment. The intestinal microbiota is the complex community of microorganisms colonizing the gastrointestinal tract. Probiotics, which are dietary or medical supplements consisting of beneficial intestinal bacteria, work in concert with endogenous intestinal microorganisms to maintain host health. Recent studies have revealed that bone loss in PMO is closely related to host immunity, which is influenced by the intestinal microbiota. The curative effects of probiotics on metabolic bone diseases have also been demonstrated. The effects of the intestinal microbiota on bone metabolism suggest a promising target for PMO management. This review seeks to summarize the critical effects of the intestinal microbiota and probiotics on PMO, with a focus on the molecular mechanisms underlying the pathogenic relationship between bacteria and host, and to define the possible treatment options.
基金supported by the National Natural Science Foundation of China (No. 20977069, 21211130108)the Natural Science Foundation of Hubei Province, China through "The Outstanding Youth Scholars Program" (No. 2007ABB028)
文摘Bimetallic Fe-Co/GAC （granular activated carbon） was prepared and used as heterogeneous catalyst in the ultrasound enhanced heterogeneous activation of peroxydisulfate （PS, S2O8 2-） process. The effect of initial pH, PS concentration, catalyst addition and stirring rate on the decolorization of Acid Orange 7 （AO7） was investigated. The results showed that the decolorization efficiency increased with an increase in PS concentration from 0.3 to 0.5 g/L and an increase in catalyst amount from 0.5 to 0.8 g/L. But further increase in PS concentration and catalyst addition would result in an unpronounced increase in decolorization efficiency. In the range of 300 to 900 r/min, stirring rate had little effect on AO7 decolorization. The catalyst stability was evaluated by measuring decolorization efficiency for four successive cycles.
基金National Natural Science Foundation of China, No.41601182 National Social Science Foundation of China, No.14AZD094+3 种基金 National Key Research and Development Plan of China, No.2016YFC0501601 China Postdoctoral Science Foundation, No.2016M592743 Fundamental Research Funds for the Central Universities, No.GK201603078 Key Project of the Ministry of Education of China, No. 15JJD790022Acknowledgments We are grateful to the anonymous reviewers for their constructive advice about the paper, and we also thank Chen Guoyong from the Hunan University, who provided important aid in calculating the annual soil conservation of Shaanxi by MATLAB programming.
文摘Spatial-explicitly mapping of the hotspots and coldspots is a vital link in the priority setting for ecosystem services （ES） conservation. However, little research has identified and tested the compactness and efficiency of their ES hotspots and coldspots, which may weaken the effectiveness of ecological conservation. In this study, based on the RUSLE model and Getis-Ord Gi＊ statistics, we quantified the variation of annual soil conservation services （SC） and identified the statistically significant hotspots and coldspots in Shaanxi Province of China from 2000 to 2013. The results indicate that, 1） areas with high SC presented a significantly increasing trend as well, while areas with low SC only changed slightly; 2） SC hotspots and coldspots showed an obvious spatial differentiation--the hotspots were mainly spatially ag- gregated in southern Shaanxi, while the coldspots were mainly distributed in the Guanzhong Basin and Sand-windy Plateau; and 3） the identified hotspots had the highest capacity of providing SC, with 29.6% of the total area providing 59.7% of the total service. In contrast, the coldspots occupied 46.3% of the total area, but only provided 17.2% of the total SC. In addition to conserving single ES, the Getis-Ord Gi＊ statistics method can also help identify multi-functional priority areas for conserving multiple ES and biodiversity.
基金supported by the National Natural Science Foundation of China(NSFC,No.21203220 and 21133011)China Postdoctoral Science Foundation(No.2014M551674)+1 种基金Jiangsu Planned Projects for Postdoctoral Research Funds(No.1302070C)the National Basic Research Program of China(973 Program,No.2011CB201404)
文摘The chemical equilibrium and reaction kinetic behavior in the synthesis of polyoxymethylene dimethyl ethers （DMMn） were investigated over sulfated titania in order to reveal the decisive factor controlling the reaction. The results showed that the molar ratio of adjacent DMMn products in equilibrium solution had the same value, which depended absolutely on the reaction temperature. Meanwhile, the reactions had the same DMMn products distributions under varied reaction conditions. The equilibrium constants of the related step-wise reactions for DMMn formation were equal, which were calculated based on the bulk compositions of the reaction solution. And thus, the selectivity to DMMn was mainly controlled by the chemical equilibrium, i.e., thermodynamic control. In brief, the present results provide some guidance for future synthesis of DMMn.
基金supported by the National Natural Science Foundation of China(Grant No.21827811)Research and development plan of key areas in Hunan Province(Grant No.2019SK2201)Innovation science and technology plan of Hunan Province(Grant No.2017XK2103).
文摘Investigation of metal–organic frameworks(MOFs)for biomedical applications has attracted much attention in recent years.MOFs are regarded as a promising class of nanocarriers for drug delivery owing to well-defined structure,ultrahigh surface area and porosity,tunable pore size,and easy chemical functionalization.In this review,the unique properties of MOFs and their advantages as nanocarriers for drug delivery in biomedical applications were discussed in the first section.Then,state-ofthe-art strategies to functionalize MOFs with therapeutic agents were summarized,including surface adsorption,pore encapsulation,covalent binding,and functional molecules as building blocks.In the third section,the most recent biological applications of MOFs for intracellular delivery of drugs,proteins,and nucleic acids,especially aptamers,were presented.Finally,challenges and prospects were comprehensively discussed to provide context for future development of MOFs as efficient drug delivery systems.
基金The authors are grateful to"Chemical Grid Project"of Beijing University of Chemical Technology for providingthe computer facilities.
文摘A subsurface flow wetland(SSFW)was simulated using a commercial computational fluid dynamic(CFD)code.The constructed media was simulated using porous media and the liquid resident time distribution(RTD)in the SSFW was obtained using the particle trajectory model.The effect of wetland configuration and operating conditions on the hydraulic performance of the SSFW were investigated.The results indicated that the hydraulic performance of the SSFW was predominantly affected by the wetland configuration.The hydr...
基金Supported by the Program for New Century Excellent Talents of China (Grant No. NCET-04-1006)the Foundation for the Author of National Excellent Doctoral Dissertation of China (Grant No. 200136)
文摘The optimal performance of heat-driven binary separation processes with linear phenomenological heat transfer law(q∝△(T-1)) is analyzed by taking the processes as heat engines which work between high-and low-temperature reservoirs and produce enthalpy and energy flows out of the system,and the temperatures of the heat reservoirs are assumed to be time-and space-variables.A numerical method is employed to solve convex optimization problem and Lagrangian function is employed to solve the average optimal control problem.The dimensionless entropy production rate coefficient and dimensionless enthalpy flow rate coefficient are adopted to indicate the major influence factors on the performance of the separation process,such as the properties of different materials and various separation requirements for the separation process.The dimensionless minimum average entropy production rate and dimensionless minimum average heat consumption of the heat-driven binary separation processes are obtained.The obtained results are compared with those obtained with the Newtonian heat transfer law(q∝△(T)).
基金supported by the National Key Research and Development Program of China (2016YFC1303900,2017YFC1700200,2017YFC1702000)the National Scientific and Technological Major Projects of China (2017ZX09101004)+2 种基金the National Natural Science Foundation of China (81703604,81773687,21602219,81573501 and 81473181)Program of Shanghai Academic/Technology Research Leader (18XD1403600)the Innovative Entrepreneurship Program of High-level Talents in Dalian (2016RQ025)
文摘Mammalian carboxylesterases(CEs) are key enzymes from the serine hydrolase superfamily.In the human body, two predominant carboxylesterases(CES1 and CES2) have been identified and extensively studied over the past decade. These two enzymes play crucial roles in the metabolism of a wide variety of endogenous esters, ester-containing drugs and environmental toxicants. The key roles of CES in both human health and xenobiotic metabolism arouse great interest in the discovery of potent CES modulators to regulate endobiotic metabolism or to improve the efficacy of ester drugs. This review covers the structural and catalytic features of CES, tissue distributions, biological functions, genetic polymorphisms, substrate specificities and inhibitor properties of CES1 and CES2, as well as the significance and recent progress on the discovery of CES modulators. The information presented here will help pharmacologists explore the relevance of CES to human diseases or to assign the contribution of certain CES in xenobiotic metabolism. It will also facilitate medicinal chemistry efforts to design prodrugs activated by a given CES isoform, or to develop potent and selective modulators of CES for potential biomedical applications.
基金supported by grants from the National Natural Science Foundation of China(81771761 and 91842304)Chinese National Key Technology R&D Program,Ministry of Science and Technology(2017YFC0907601 and 2017YFC0907605)+2 种基金General Research Fund,Hong Kong Research Grants Council(17114515 and 17149716)Hong Kong Croucher Foundation(260960116)Sanming Project of Medicine in Shenzhen(SZSM201512019).
文摘Increased numbers of T follicular helper(Tfh)cells have been implicated in the development of autoimmune diseases including primary Sjögren’s syndrome(pSS),but how the Tfh cell response is regulated during autoimmune pathogenesis remains largely unclear.Here,we first found negative correlations between IL-10^(+)regulatory B(Breg)cell numbers and Tfh cell responses and disease activity in patients with pSS and mice with experimental Sjögren’s syndrome(ESS).Moreover,we detected high expression of IL-10 receptor on Tfh cells and their precursors in both humans and mice.In culture,IL-10 suppressed human and murine Tfh cell differentiation by promoting STAT5 phosphorylation.By using an adoptive transfer approach and two-photon live imaging,we found significantly increased numbers of Tfh cells with enhanced T cell homing into B cell follicles in the draining cervical lymph nodes of RAG-2−/−mice transferred with IL-10-deficient B cells during ESS development compared with those of RAG-2−/−mice transferred with wild-type B cells.In ESS mice,CD19^(+)CD1d^(hi)CD5^(+)Breg cells with decreased IL-10 production exhibited severely impaired suppressive effects on T cell proliferation.Consistently,CD19^(+)CD24^(+)CD38^(hi) Breg cells from pSS patients showed significantly reduced IL-10 production with defective inhibitory function in the suppression of autologous Tfh cell expansion.Furthermore,the adoptive transfer of IL-10-producing Breg cells markedly suppressed the Tfh cell response and ameliorated ESS progression in ESS mice.Together,these findings demonstrate a critical role for IL-10-producing Breg cells in restraining the effector Tfh cell response during pSS development.
基金Supported by the International Partnership Program of Chinese Academy of Sciences(134111KYSB20160031)National Natural Science Foundation of China(41875132).
文摘The Earth–Climate System Model(ECSM)is an important platform for multi-disciplinary and multi-sphere integration research,and its development is at the frontier of international geosciences,especially in the field of global change.The research and development(R&D)of ECSM in China began in the 1980 s and have achieved great progress.In China,ECSMs are now mainly developed at the Chinese Academy of Sciences,ministries,and universities.Following a brief review of the development history of Chinese ECSMs,this paper summarized the technical characteristics of nine Chinese ECSMs participating in the Coupled Model Intercomparison Project Phase 6 and preliminarily assessed the basic performances of four Chinese models in simulating the global climate and the climate in East Asia.The projected changes of global precipitation and surface air temperature and the associated relationship with the equilibrium climate sensitivity under four shared socioeconomic path scenarios were also discussed.Finally,combined with the international situation,from the perspective of further improvement,eight directions were proposed for the future development of Chinese ECSMs.
