Abiotic stresses and soil nutrient limitations are major environmental conditions that reduce plant growth,productivity and quality.Plants have evolved mechanisms to perceive these environmental challenges,transmit th...Abiotic stresses and soil nutrient limitations are major environmental conditions that reduce plant growth,productivity and quality.Plants have evolved mechanisms to perceive these environmental challenges,transmit the stress signals within cells as well as between cells and tissues,and make appropriate adjustments in their growth and development in order to survive and reproduce.In recent years,significant progress has been made on many fronts of the stress signaling research,particularly in understanding the downstream signaling events that culminate at the activation of stress-and nutrient limitation-responsive genes,cellular ion homeostasis,and growth adjustment.However,the revelation of the early events of stress signaling,particularly the identification of primary stress sensors,still lags behind.In this review,we summarize recent work on the genetic and molecular mechanisms of plant abiotic stress and nutrient limitation sensing and signaling and discuss new directions for future studies.展开更多
In 1995,Yu et al.[1]first reported bulk-heterojunction(BHJ)solar cells with a conjugated polymer donor and a fullerene acceptor as the active materials.From then on,BHJ organic solar cells(OSCs)have attracted academic...In 1995,Yu et al.[1]first reported bulk-heterojunction(BHJ)solar cells with a conjugated polymer donor and a fullerene acceptor as the active materials.From then on,BHJ organic solar cells(OSCs)have attracted academic and industrial interests due to the advantages like lightweight,flexibility and roll-to-roll fabrication.Nowadays,17%power conversion efficiencies(PCEs)have been achieved in the state-of-the-art OSCs[2,3].The remarkable progress in OSCs relies on the continuously emerging new materials and device fabrication technologies,and the understanding on film morphology and device physics[4,5].展开更多
Organic solar cells （OSCs） have advantages like light-weight, flexibility, colorfulness and solution processability [1 ]. The active layer of OSCs generally contains two organic semiconductors： an electron donor an...Organic solar cells （OSCs） have advantages like light-weight, flexibility, colorfulness and solution processability [1 ]. The active layer of OSCs generally contains two organic semiconductors： an electron donor and an electron acceptor. The donor and acceptor make nanoscale phase separation to allow efficient exciton dissociation and also form a three-dimensional （3D） passage to rapidly transfer free charge carriers to respective electrodes.展开更多
Shale with high quartz, feldspar and carbonate, will have low Poisson＇s ratio, high Young＇s modulus and high brittleness. As a result, the shale is conducive to produce natural and induced fractures under external f...Shale with high quartz, feldspar and carbonate, will have low Poisson＇s ratio, high Young＇s modulus and high brittleness. As a result, the shale is conducive to produce natural and induced fractures under external forces. In general, there is a good correlation between fracture development in shale and the volume of brittle minerals present. Shale with high TOC or abnormally high pressure has well-developed fractures. Shale fracture development also shows a positive correlation with total gas accumulation and free gas volume, i.e., the better shale fractures are developed, the greater the gas accumulation and therefore the higher the gas production. Fractures provide migration conduits and accumulation spaces for natural gas and formation water, which are favorable for the volumetric increase of free natural gas. Wider fractures in shale result in gas loss. In North America, there is a high success ratio of shale gas exploration and high gas production from high-angle fracture zones in shale. Good natural gas shows or low yield producers in the Lower Paleozoic marine organic matter-rich rocks in the Sichuan Basin are closely related to the degree of fracture development in brittle shales.展开更多
Four batch experiments of hydrolysis and acidification were carried out to investigate the distributions of proteins （PN） and polysaccharides （PS） in the sludge, the PN/PS ratio, the particle sizes, and their rela...Four batch experiments of hydrolysis and acidification were carried out to investigate the distributions of proteins （PN） and polysaccharides （PS） in the sludge, the PN/PS ratio, the particle sizes, and their relationship with sludge dewaterability （as determined by capillary suction time, CST）. The sludge flocs were stratified through centrifugation- and ultrasound-based method into four fractions： （1） slime, （2） loosely bound extracellular polymeric substances （LB-EPS）, （3） tightly bound EPS （TB-EPS）, and （4） pellet. The results showed that PN was mainly partitioned in the pellet （80.7%） and TB-EPS （9.6%） fractions, while PS distributed evenly in the four fractions. During hydrolysis and acidification, PN was transferred from the pellet and TB-EPS fractions to the slime fraction, but PS had no significant transfer trends. The mean particle sizes of the sludge flocs decreased with hydrolysis and acidification. The pH had a more significant influence on the dewaterability of sludge flocs than temperature. Sludge dewaterability during hydrolysis and acidification processes greatly deteriorated from 9.7 s at raw sludge to 340-450 s under alkaline conditions. However, it was just slightly increased under acidic conditions. Further investigation suggested that CST was affected by soluble PN, soluble PN/PS, and particle sizes of sludge flocs, but was affected slightly by total PN, PS, or PN/PS in the whole sludge flocs and other fractions （except slime）.展开更多
Gastrodin, the major component isolated from the rhizome of the Chinese traditional medicinal herb Gastrodia elata（‘‘Tianma＇＇）, has a long history in the treatment of epilepsy and other neurological disorders.Ho...Gastrodin, the major component isolated from the rhizome of the Chinese traditional medicinal herb Gastrodia elata（‘‘Tianma＇＇）, has a long history in the treatment of epilepsy and other neurological disorders.However, the molecular mechanisms are not clear. Here,we found that gastrodin ameliorated pentylenetetrazole（PTZ）-induced epileptic seizures with improvement of the electroencephalographic pattern in mice. Further studies demonstrated that gastrodin decreased the levels of the pro-inflammatory cytokines interleukin-1b and tumor necrosis factor-a while increasing interleukin-10, an antiinflammatory cytokine in the brain. Furthermore, gastrodin attenuated the PTZ-induced microglial activation along with inhibition of mitogen-activated protein kinases,c AMP response element binding protein, and NF-j B. Our data suggest that gastrodin attenuates seizures by modulating the mitogen-activated protein kinase-associated inflammatory responses.展开更多
Most orogenic belts have experienced a complex accretionary process with multiple episodes of sea?oor subduction and trench retreat.This accretionary process is important in continenta development and growth[1,2].Thre...Most orogenic belts have experienced a complex accretionary process with multiple episodes of sea?oor subduction and trench retreat.This accretionary process is important in continenta development and growth[1,2].Three giant orogens extend in China,e.g.,the Central Asian Orogen in the north,the Central China Orogen in the middle and the Himalayan Orogen in the southwest.They are keys for the formation of the Eurasian continent(Fig.1a).The Central China Orogen展开更多
Nonfullerene-based organic solar cells(NFOSCs)have received great interest recently due to their higher performance and greater potential compared with fullerene-based solar cells[1].Power conversion efficiencies(PCEs...Nonfullerene-based organic solar cells(NFOSCs)have received great interest recently due to their higher performance and greater potential compared with fullerene-based solar cells[1].Power conversion efficiencies(PCEs)over 13% have been realized in single-junction NFOSCs[2].Compared with traditional fullerene acceptors,the greatest advantage of nonfullerene acceptors is their stronger light-harvesting capability in the visible and展开更多
Effect of ultrasonic pretreatment on sludge dewaterability was determined and the fate of extracellular polymeric substances （EPS） matrix in mesophilic anaerobic digestion after ultrasonic pretreatment was studied. ...Effect of ultrasonic pretreatment on sludge dewaterability was determined and the fate of extracellular polymeric substances （EPS） matrix in mesophilic anaerobic digestion after ultrasonic pretreatment was studied. Characteristics of proteins （PN）, polysaccharides （PS）, excitation-emission matrix （EEM） fluorescence spectroscopy and molecular weight （MW） distribution of dissolved organic matters （DOM） in different EPS fractions were evaluated. The results showed that after ultrasonic pretreatment, the normalized capillary suction time （CST） decreased from 44.4 to 11.1 （sec·L）/g total suspended solids （TSS） during anaerobic digestion, indicating that sludge dewaterability was greatly improved. The normalized CST was significantly correlated with PN concentration （R2 = 0.92, p 〈 0.01） and the PN/PS ratio （R2 = 0.84, p 〈 0.01） in the loosely bound EPS （LB-EPS） fraction. Meanwhile, the average MW of DOM in the LB- EPS and tightly bound EPS （TB-EPS） fractions also had a good correlation with the normalized CST （R2 〉 0.66, p 〈 0.01）. According to EEM fluorescence spectroscopy, tryptophan-like substances intensities in the slime, LB-EPS and TB-EPS fractions were correlated with the normalized CST. The organic matters in the EPS matrix played an important role in influencing sludge dewaterability.展开更多
In higher plants, the splicing of organelle-encoded mRNA involves a complex collaboration with nuclear- encoded proteins. Pentatricopeptide repeat （PPR） proteins have been implicated in these RNA-protein interaction...In higher plants, the splicing of organelle-encoded mRNA involves a complex collaboration with nuclear- encoded proteins. Pentatricopeptide repeat （PPR） proteins have been implicated in these RNA-protein interactions. In this study, we performed the cloning and functional characterization of maize Defective kernel 35 （Dek35）. The dek35-ref mutant is a lethal-seed mutant with developmental deficiency. Dek35 was cloned through Mutator tag isolation and further confirmed by four additional independent mutant alleles. Dek35 encodes an P-type PPR protein that targets the mitochondria. The dek35 mutation causes significant reduction in the accumulation of DEK35 proteins and reduced splicing efficiency of mitochon- drial nad4 intron 1. Analysis of mitochondrial complex in dek35 immature seeds indicated severe deficiency in the complex I assembly and NADH dehydrogenase activity. Transcriptome analysis of dek35 endosperm revealed enhanced expression of genes involved in the alternative respiratory pathway and extensive differentially expressed genes related to mitochondrial function and activity. Collectively, these results indicate that Dek35 encodes an PPR protein that affects the cis-splicing of mitochondrial nad4 intron 1 and is required for mitochondrial function and seed development.展开更多
The martensitic/ferritic steels have been used as boiler and turbine materials in power plants, and also been selected as potential materials for structural materials in nuclear reactors. In this paper, the kinetic an...The martensitic/ferritic steels have been used as boiler and turbine materials in power plants, and also been selected as potential materials for structural materials in nuclear reactors. In this paper, the kinetic analysis of the martensite formation and microstructural control of high-Cr martensitic/ferritic steels are reviewed. A modular approach, incorporating Fisher partitioning nucleation and anisotropic growth for impingement, was proposed to describe the martensite formation kinetics under different cooling rates.The kinetic analysis suggested a thermal-activated growth feature occurring during the martensitic transformation of martensitic steels. The microstructure can be tuned by composition optimization and various combinations of heat treatment parameters(temperature, time, severe and minor deformation).For the application in power plant, the potential of boundary-design, refinement of original austenite grain size and the final martensitic lath, pinning effect of stable carbides, in improving the performances of martensitic/ferritic steels at elevated temperatures should be investigated more thoroughly.Furthermore, efforts should be made to explore the effects of retained austenite on the improvement of high-temperature creep strength. For the application of nuclear plants, attempts should also be made to produce Fe powders with uniformly distributed oxide particles by chemical reactions.展开更多
Background:Few studies have assessed the relationship between multimorbidity patterns and mortality risk in the Chinese population.We aimed to identify multimorbidity patterns and examined the associations of multimor...Background:Few studies have assessed the relationship between multimorbidity patterns and mortality risk in the Chinese population.We aimed to identify multimorbidity patterns and examined the associations of multimorbidity patterns and the number of chronic diseases with the risk of mortality among Chinese middle-aged and older adults.Methods:We used data from the China Kadoorie Biobank and included 512,723 participants aged 30 to 79 years.Multimorbidity was defined as the presence of two or more of the 15 chronic diseases collected by self-report or physical examination at baseline.Multimorbidity patterns were identified using hierarchical cluster analysis.Cox regression was used to estimate the associations of multimorbidity patterns and the number of chronic diseases with all-cause and cause-specific mortality.Results:Overall,15.8%of participants had multimorbidity.The prevalence of multimorbidity increased with age and was higher in urban than rural participants.Four multimorbidity patterns were identified,including cardiometabolic multimorbidity(diabetes,coronary heart disease,stroke,and hypertension),respiratory multimorbidity(tuberculosis,asthma,and chronic obstructive pulmonary disease),gastrointestinal and hepatorenal multimorbidity(gallstone disease,chronic kidney disease,cirrhosis,peptic ulcer,and cancer),and mental and arthritis multimorbidity(neurasthenia,psychiatric disorder,and rheumatoid arthritis).During a median of 10.8 years of follow-up,49,371 deaths occurred.Compared with participants without multimorbidity,cardiometabolic multimorbidity(hazard ratios[HR]=2.20,95%confidence intervals[CI]:2.14-2.26)and respiratory multimorbidity(HR=2.13,95%CI:1.97-2.31)demonstrated relatively higher risks of mortality,followed by gastrointestinal and hepatorenal multimorbidity(HR=1.33,95%CI:1.22-1.46).The mortality risk increased by 36%(HR=1.36,95%CI:1.35-1.37)with every additional disease.Conclusion:Cardiometabolic multimorbidity and respiratory multimorbidity posed the highest threat on mortality risk and d展开更多
Irisin is a polypeptide hormone derived from the proteolytic cleavage of fibronectin-type III domain- containing 5 （FNDC5） protein. Once released to circulation upon exercise or cold exposure, irisin stimulates brow...Irisin is a polypeptide hormone derived from the proteolytic cleavage of fibronectin-type III domain- containing 5 （FNDC5） protein. Once released to circulation upon exercise or cold exposure, irisin stimulates browning of white adipose tissue （WAT） and uncoupling protein I （UCP1） expression, leading to an increase in total body energy expenditure by augmented UCPl-mediated thermogenesis. It is currently unknown whether irisin is secreted by bone upon exercise or whether it regulates bone metabolism in vivo. In this study, we found that 2 weeks of voluntary wheel-running exercise induced high levels of FNDC5 messenger RNA as well as FNDC5/irisin protein expression in murine bone tissues. Increased immunoreactivity due to exercise-induced FNDC5/irisin expression was detected in different regions of exercised femoral bones, including growth plate, trabecular bone, cortical bone, articular cartilage, and bone-tendon interface. Exercise also increased expression of osteogenic markers in bone and that of UCP1 in WAT, and led to bodyweight loss. Irisin intraperitoneal （IP） administration resulted in increased trabecular and cortical bone thickness and osteoblasts numbers, and concurrently induced UCP1 expression in subcutaneous WAT. Lentiviral FNDC5 IP administration increased cortical bone thickness. In vitro studies in bone cells revealed irisin increases osteoblastogenesis and mineralization, and inhibits receptor activator of nuclear factor-kB ligand （RANKL）- induced osteoclastogenesis. Taken together, our findings show that voluntary exercise increases irisin production in bone, and that an increase in circulating irisin levels enhances osteogenesis in mice.展开更多
文摘Abiotic stresses and soil nutrient limitations are major environmental conditions that reduce plant growth,productivity and quality.Plants have evolved mechanisms to perceive these environmental challenges,transmit the stress signals within cells as well as between cells and tissues,and make appropriate adjustments in their growth and development in order to survive and reproduce.In recent years,significant progress has been made on many fronts of the stress signaling research,particularly in understanding the downstream signaling events that culminate at the activation of stress-and nutrient limitation-responsive genes,cellular ion homeostasis,and growth adjustment.However,the revelation of the early events of stress signaling,particularly the identification of primary stress sensors,still lags behind.In this review,we summarize recent work on the genetic and molecular mechanisms of plant abiotic stress and nutrient limitation sensing and signaling and discuss new directions for future studies.
基金the National Key Research and Development Program of China (2017YFA0206600)the National Natural Science Foundation of China (51773045, 21572041, 21772030 and 51922032)the Youth Association for Promoting Innovation (CAS) for financial support.
文摘In 1995,Yu et al.[1]first reported bulk-heterojunction(BHJ)solar cells with a conjugated polymer donor and a fullerene acceptor as the active materials.From then on,BHJ organic solar cells(OSCs)have attracted academic and industrial interests due to the advantages like lightweight,flexibility and roll-to-roll fabrication.Nowadays,17%power conversion efficiencies(PCEs)have been achieved in the state-of-the-art OSCs[2,3].The remarkable progress in OSCs relies on the continuously emerging new materials and device fabrication technologies,and the understanding on film morphology and device physics[4,5].
基金supported by the National Natural Science Foundation of China (U1401244, 21374025, 21372053, 21572041, and 51503050)the National Key Research and Development Program of China (2017YFA0206600)+1 种基金State Key Laboratory of Luminescent Materials and Devices (2016-skllmd-05)Youth Association for Promoting Innovation (CAS)
文摘Organic solar cells （OSCs） have advantages like light-weight, flexibility, colorfulness and solution processability [1 ]. The active layer of OSCs generally contains two organic semiconductors： an electron donor and an electron acceptor. The donor and acceptor make nanoscale phase separation to allow efficient exciton dissociation and also form a three-dimensional （3D） passage to rapidly transfer free charge carriers to respective electrodes.
基金sponsored jointly by the National Natural Science Foundation Project(41072098,41002072)National Special Proiect of Investigation and Evaluation on Strategic Screening for National Oil & Gas Resources-"Potentials of Shale Gas Resources in Kev Chinese Areas and Optimization of Favorable Areas"(No.2009GYXQ-15)+2 种基金Major Special Project for National Science and Technology(2008ZX05031-001-005HZ)"973"Project of Development Plan for National Key Fundamental Studies(2006CB202302)CNPC Science & Technology Innovation Foundation Project(2008D-5006-01-06)
文摘Shale with high quartz, feldspar and carbonate, will have low Poisson＇s ratio, high Young＇s modulus and high brittleness. As a result, the shale is conducive to produce natural and induced fractures under external forces. In general, there is a good correlation between fracture development in shale and the volume of brittle minerals present. Shale with high TOC or abnormally high pressure has well-developed fractures. Shale fracture development also shows a positive correlation with total gas accumulation and free gas volume, i.e., the better shale fractures are developed, the greater the gas accumulation and therefore the higher the gas production. Fractures provide migration conduits and accumulation spaces for natural gas and formation water, which are favorable for the volumetric increase of free natural gas. Wider fractures in shale result in gas loss. In North America, there is a high success ratio of shale gas exploration and high gas production from high-angle fracture zones in shale. Good natural gas shows or low yield producers in the Lower Paleozoic marine organic matter-rich rocks in the Sichuan Basin are closely related to the degree of fracture development in brittle shales.
基金supported by the National Hi-Tech Research and Development Program (863) of China (No. 2006AA06Z384).
文摘Four batch experiments of hydrolysis and acidification were carried out to investigate the distributions of proteins （PN） and polysaccharides （PS） in the sludge, the PN/PS ratio, the particle sizes, and their relationship with sludge dewaterability （as determined by capillary suction time, CST）. The sludge flocs were stratified through centrifugation- and ultrasound-based method into four fractions： （1） slime, （2） loosely bound extracellular polymeric substances （LB-EPS）, （3） tightly bound EPS （TB-EPS）, and （4） pellet. The results showed that PN was mainly partitioned in the pellet （80.7%） and TB-EPS （9.6%） fractions, while PS distributed evenly in the four fractions. During hydrolysis and acidification, PN was transferred from the pellet and TB-EPS fractions to the slime fraction, but PS had no significant transfer trends. The mean particle sizes of the sludge flocs decreased with hydrolysis and acidification. The pH had a more significant influence on the dewaterability of sludge flocs than temperature. Sludge dewaterability during hydrolysis and acidification processes greatly deteriorated from 9.7 s at raw sludge to 340-450 s under alkaline conditions. However, it was just slightly increased under acidic conditions. Further investigation suggested that CST was affected by soluble PN, soluble PN/PS, and particle sizes of sludge flocs, but was affected slightly by total PN, PS, or PN/PS in the whole sludge flocs and other fractions （except slime）.
文摘Gastrodin, the major component isolated from the rhizome of the Chinese traditional medicinal herb Gastrodia elata（‘‘Tianma＇＇）, has a long history in the treatment of epilepsy and other neurological disorders.However, the molecular mechanisms are not clear. Here,we found that gastrodin ameliorated pentylenetetrazole（PTZ）-induced epileptic seizures with improvement of the electroencephalographic pattern in mice. Further studies demonstrated that gastrodin decreased the levels of the pro-inflammatory cytokines interleukin-1b and tumor necrosis factor-a while increasing interleukin-10, an antiinflammatory cytokine in the brain. Furthermore, gastrodin attenuated the PTZ-induced microglial activation along with inhibition of mitogen-activated protein kinases,c AMP response element binding protein, and NF-j B. Our data suggest that gastrodin attenuates seizures by modulating the mitogen-activated protein kinase-associated inflammatory responses.
基金supported by the Major State Basic Research Development Program (2015CB856105)National Natural Science Foundation of China (41572040 and 41372060)
文摘Most orogenic belts have experienced a complex accretionary process with multiple episodes of sea?oor subduction and trench retreat.This accretionary process is important in continenta development and growth[1,2].Three giant orogens extend in China,e.g.,the Central Asian Orogen in the north,the Central China Orogen in the middle and the Himalayan Orogen in the southwest.They are keys for the formation of the Eurasian continent(Fig.1a).The Central China Orogen
基金supported by the National Natural Science Foundation of China (U1401244, 21374025,21372053,21572041,and 51503050)the National Key Research and Development Program of China (2017YFA0206600)+2 种基金the State Key Laboratory of Luminescent Materials and Devices(2016-skllmd-05)the Youth Association for Promoting Innovation(CAS)the U.S.Office of Naval Research(N00014-15-1-2244)for financial support
文摘Nonfullerene-based organic solar cells(NFOSCs)have received great interest recently due to their higher performance and greater potential compared with fullerene-based solar cells[1].Power conversion efficiencies(PCEs)over 13% have been realized in single-junction NFOSCs[2].Compared with traditional fullerene acceptors,the greatest advantage of nonfullerene acceptors is their stronger light-harvesting capability in the visible and
基金supported by the National Natural Science Foundation of China (No. 20977066)the National Key Project for Water Pollution Control (No.2008ZX07316-002, 2008ZX07317-003)the Specialized Research Found for Doctoral Program of Higher Education of China (No. 200802470029)
文摘Effect of ultrasonic pretreatment on sludge dewaterability was determined and the fate of extracellular polymeric substances （EPS） matrix in mesophilic anaerobic digestion after ultrasonic pretreatment was studied. Characteristics of proteins （PN）, polysaccharides （PS）, excitation-emission matrix （EEM） fluorescence spectroscopy and molecular weight （MW） distribution of dissolved organic matters （DOM） in different EPS fractions were evaluated. The results showed that after ultrasonic pretreatment, the normalized capillary suction time （CST） decreased from 44.4 to 11.1 （sec·L）/g total suspended solids （TSS） during anaerobic digestion, indicating that sludge dewaterability was greatly improved. The normalized CST was significantly correlated with PN concentration （R2 = 0.92, p 〈 0.01） and the PN/PS ratio （R2 = 0.84, p 〈 0.01） in the loosely bound EPS （LB-EPS） fraction. Meanwhile, the average MW of DOM in the LB- EPS and tightly bound EPS （TB-EPS） fractions also had a good correlation with the normalized CST （R2 〉 0.66, p 〈 0.01）. According to EEM fluorescence spectroscopy, tryptophan-like substances intensities in the slime, LB-EPS and TB-EPS fractions were correlated with the normalized CST. The organic matters in the EPS matrix played an important role in influencing sludge dewaterability.
文摘In higher plants, the splicing of organelle-encoded mRNA involves a complex collaboration with nuclear- encoded proteins. Pentatricopeptide repeat （PPR） proteins have been implicated in these RNA-protein interactions. In this study, we performed the cloning and functional characterization of maize Defective kernel 35 （Dek35）. The dek35-ref mutant is a lethal-seed mutant with developmental deficiency. Dek35 was cloned through Mutator tag isolation and further confirmed by four additional independent mutant alleles. Dek35 encodes an P-type PPR protein that targets the mitochondria. The dek35 mutation causes significant reduction in the accumulation of DEK35 proteins and reduced splicing efficiency of mitochon- drial nad4 intron 1. Analysis of mitochondrial complex in dek35 immature seeds indicated severe deficiency in the complex I assembly and NADH dehydrogenase activity. Transcriptome analysis of dek35 endosperm revealed enhanced expression of genes involved in the alternative respiratory pathway and extensive differentially expressed genes related to mitochondrial function and activity. Collectively, these results indicate that Dek35 encodes an PPR protein that affects the cis-splicing of mitochondrial nad4 intron 1 and is required for mitochondrial function and seed development.
基金the China National Funds for Distinguished Young Scientists (Grant No. 51325401)the International Thermonuclear Experimental Reactor (ITER) Program Special Project (Grant Nos. 2014GB125006 and 2015GB119001)+1 种基金the National High Technology Research and Development Program ("863" Program) of China (Granted No. SS2015AA042005)the National Natural Science Foundation of China (Grant No. 51474156)
文摘The martensitic/ferritic steels have been used as boiler and turbine materials in power plants, and also been selected as potential materials for structural materials in nuclear reactors. In this paper, the kinetic analysis of the martensite formation and microstructural control of high-Cr martensitic/ferritic steels are reviewed. A modular approach, incorporating Fisher partitioning nucleation and anisotropic growth for impingement, was proposed to describe the martensite formation kinetics under different cooling rates.The kinetic analysis suggested a thermal-activated growth feature occurring during the martensitic transformation of martensitic steels. The microstructure can be tuned by composition optimization and various combinations of heat treatment parameters(temperature, time, severe and minor deformation).For the application in power plant, the potential of boundary-design, refinement of original austenite grain size and the final martensitic lath, pinning effect of stable carbides, in improving the performances of martensitic/ferritic steels at elevated temperatures should be investigated more thoroughly.Furthermore, efforts should be made to explore the effects of retained austenite on the improvement of high-temperature creep strength. For the application of nuclear plants, attempts should also be made to produce Fe powders with uniformly distributed oxide particles by chemical reactions.
基金supported by grants from the National Natural Science Foundation of China(No.81941018)The CKB baseline survey and the first re-survey were supported by a grant from the Kadoorie Charitable Foundation in Hong Kong,China.The long-term follow-up is supported by grants from the UK Wellcome Trust(Nos.212946/Z/18/Z,202922/Z/16/Z,104085/Z/14/Z,and 088158/Z/09/Z)+2 种基金grants from the National Key R&D Program of China(Nos.2016YFC0900500 and 2016YFC1303904)National Natural Science Foundation of China(No.81390540)Chinese Ministry of Science and Technology(No.2011BAI09B01)。
文摘Background:Few studies have assessed the relationship between multimorbidity patterns and mortality risk in the Chinese population.We aimed to identify multimorbidity patterns and examined the associations of multimorbidity patterns and the number of chronic diseases with the risk of mortality among Chinese middle-aged and older adults.Methods:We used data from the China Kadoorie Biobank and included 512,723 participants aged 30 to 79 years.Multimorbidity was defined as the presence of two or more of the 15 chronic diseases collected by self-report or physical examination at baseline.Multimorbidity patterns were identified using hierarchical cluster analysis.Cox regression was used to estimate the associations of multimorbidity patterns and the number of chronic diseases with all-cause and cause-specific mortality.Results:Overall,15.8%of participants had multimorbidity.The prevalence of multimorbidity increased with age and was higher in urban than rural participants.Four multimorbidity patterns were identified,including cardiometabolic multimorbidity(diabetes,coronary heart disease,stroke,and hypertension),respiratory multimorbidity(tuberculosis,asthma,and chronic obstructive pulmonary disease),gastrointestinal and hepatorenal multimorbidity(gallstone disease,chronic kidney disease,cirrhosis,peptic ulcer,and cancer),and mental and arthritis multimorbidity(neurasthenia,psychiatric disorder,and rheumatoid arthritis).During a median of 10.8 years of follow-up,49,371 deaths occurred.Compared with participants without multimorbidity,cardiometabolic multimorbidity(hazard ratios[HR]=2.20,95%confidence intervals[CI]:2.14-2.26)and respiratory multimorbidity(HR=2.13,95%CI:1.97-2.31)demonstrated relatively higher risks of mortality,followed by gastrointestinal and hepatorenal multimorbidity(HR=1.33,95%CI:1.22-1.46).The mortality risk increased by 36%(HR=1.36,95%CI:1.35-1.37)with every additional disease.Conclusion:Cardiometabolic multimorbidity and respiratory multimorbidity posed the highest threat on mortality risk and d
基金supported by a R01DE21464 through the National Institutes of Healthan Innovation in Oral Care Award through International Association for Dental Research and Glaxo Smith Kline Consumer Healthcare+2 种基金an Award through International Team of Implantology to JCby GZUCM Science Fund for Creative Research Groups(2016KYTD10)GZUCM Torch Program(A1-AFD015142Z08)to JZ
文摘Irisin is a polypeptide hormone derived from the proteolytic cleavage of fibronectin-type III domain- containing 5 （FNDC5） protein. Once released to circulation upon exercise or cold exposure, irisin stimulates browning of white adipose tissue （WAT） and uncoupling protein I （UCP1） expression, leading to an increase in total body energy expenditure by augmented UCPl-mediated thermogenesis. It is currently unknown whether irisin is secreted by bone upon exercise or whether it regulates bone metabolism in vivo. In this study, we found that 2 weeks of voluntary wheel-running exercise induced high levels of FNDC5 messenger RNA as well as FNDC5/irisin protein expression in murine bone tissues. Increased immunoreactivity due to exercise-induced FNDC5/irisin expression was detected in different regions of exercised femoral bones, including growth plate, trabecular bone, cortical bone, articular cartilage, and bone-tendon interface. Exercise also increased expression of osteogenic markers in bone and that of UCP1 in WAT, and led to bodyweight loss. Irisin intraperitoneal （IP） administration resulted in increased trabecular and cortical bone thickness and osteoblasts numbers, and concurrently induced UCP1 expression in subcutaneous WAT. Lentiviral FNDC5 IP administration increased cortical bone thickness. In vitro studies in bone cells revealed irisin increases osteoblastogenesis and mineralization, and inhibits receptor activator of nuclear factor-kB ligand （RANKL）- induced osteoclastogenesis. Taken together, our findings show that voluntary exercise increases irisin production in bone, and that an increase in circulating irisin levels enhances osteogenesis in mice.
