Purpose:The aim of the current study was to investigate the association of accelerometer-measured sleep duration and different intensities of physical activity(PA)with the risk of incident type 2 diabetes in a populat...Purpose:The aim of the current study was to investigate the association of accelerometer-measured sleep duration and different intensities of physical activity(PA)with the risk of incident type 2 diabetes in a population-based prospective cohort study.Methods:Altogether,88,000 participants(mean age=62.2±7.9 years,mean±SD)were included from the UK Biobank.Sleep duration(short:<6 h/day;normal:6-8 h/day;long:>8 h/day)and PA of different intensities were measured using a wrist-won accelerometer over a 7-day period between 2013 and 2015.PA was classified according to the median or World Health Organization-recommendation:total volume of PA(high,low),moderate-to-vigorous PA(MVPA)(recommended,not recommended),and light-intensity PA(high,low).Incidence of type 2diabetes was ascertained using hospital records or death registries.Results:During a median follow-up of 7.0 years,1615 incident type 2 diabetes cases were documented.Compared with normal sleep duration,short(hazard ratio(HR)=1.21,95%confidence interval(95%CI):1.03-1.41)but not long sleep duration(HR=1.01,95%CI:0.89-1.15)was associated with excessive type 2 diabetes risk.This increased risk among short sleepers seems to be protected against by PA.Compared with normal sleepers with high or recommended PA,short sleepers with low volume of PA(HR=1.81,95%CI:1.46-2.25),not recommended(below the World Health Organization-recommended level of)MVPA(HR=1.92,95%CI:1.55-2.36),or low light-intensity PA(HR=1.49,95%CI:1.13-1.90)had a higher risk of type 2 diabetes,while short sleepers with a high volume of PA(HR=1.14,95%CI:0.88-1.49),recommended MVPA(HR=1.02,95%CI:0.71-1.48),or high light-intensity PA(HR=1.14,95%CI:0.92-1.41)did not.Conclusion:Accelerometer-measured short but not long sleep duration was associated with a higher risk of incident type 2 diabetes.A higher level of PA,regardless of intensity,potentially ameliorates this excessive risk.展开更多
Improved radio-frequency(RF)power performance of InAlN/GaN high electron mobility transistor(HEMT)is achieved by optimizing the rapid thermal annealing(RTA)process for high-performance low-voltage terminal application...Improved radio-frequency(RF)power performance of InAlN/GaN high electron mobility transistor(HEMT)is achieved by optimizing the rapid thermal annealing(RTA)process for high-performance low-voltage terminal applications.By optimizing the RTA temperature and time,the optimal annealing condition is found to enable low parasitic resistance and thus a high-performance device.Besides,compared with the non-optimized RTA HEMT,the optimized one demonstrates smoother ohmic metal surface morphology and better heterojunction quality including the less degraded heterojunction sheet resistance and clearer heterojunction interfaces as well as negligible material out-diffusion from the barrier to the channel and buffer.Benefiting from the lowered parasitic resistance,improved maximum output current density of 2279 mA·mm^(-1)and higher peak extrinsic transconductance of 526 mS·mm^(-1)are obtained for the optimized RTA HEMT.In addition,due to the superior heterojunction quality,the optimized HEMT shows reduced off-state leakage current of 7×10^(-3)mA·mm^(-1)and suppressed current collapse of only 4%,compared with those of 1×10^(-1)mA·mm^(-1)and 15%for the non-optimized one.At 8 GHz and V_(DS)of 6 V,a significantly improved power-added efficiency of 62%and output power density of 0.71 W·mm^(-1)are achieved for the optimized HEMT,as the result of the improvement in output current,knee voltage,off-state leakage current,and current collapse,which reveals the tremendous advantage of the optimized RTA HEMT in high-performance low-voltage terminal applications.展开更多
The biomolecular mechanisms that regulate tooth root development and odontoblast differentiation are poorly understood.We found that Atp6i deficient mice(Atp6i^(−/−))arrested tooth root formation,indicated by truncate...The biomolecular mechanisms that regulate tooth root development and odontoblast differentiation are poorly understood.We found that Atp6i deficient mice(Atp6i^(−/−))arrested tooth root formation,indicated by truncated Hertwig’s epithelial root sheath(HERS)progression.Furthermore,Atp6i deficiency significantly reduced the proliferation and differentiation of radicular odontogenic cells responsible for root formation.Atp6i^(−/−)mice had largely decreased expression of odontoblast differentiation marker gene expression profiles(Col1a1,Nfic,Dspp,and Osx)in the alveolar bone.Atp6i^(−/−)mice sample RNA-seq analysis results showed decreased expression levels of odontoblast markers.Additionally,there was a significant reduction in Smad2/3 activation,inhibiting transforming growth factor-β(TGF-β)signaling in Atp6i^(−/−)odontoblasts.Through treating pulp precursor cells with Atp6i^(−/−)or wild-type OC bone resorption-conditioned medium,we found the latter medium to promote odontoblast differentiation,as shown by increased odontoblast differentiation marker genes expression(Nfic,Dspp,Osx,and Runx2).This increased expression was significantly blocked by anti-TGF-β1 antibody neutralization,whereas odontoblast differentiation and Smad2/3 activation were significantly attenuated by Atp6i^(−/−)OC conditioned medium.Importantly,ectopic TGF-β1 partially rescued root development and root dentin deposition of Atp6i^(−/−)mice tooth germs were transplanted under mouse kidney capsules.Collectively,our novel data shows that the prevention of TGF-β1 release from the alveolar bone matrix due to OC dysfunction may lead to osteopetrosis-associated root formation via impaired radicular odontoblast differentiation.As such,this study uncovers TGF-β1/Smad2/3 as a key signaling pathway regulating odontoblast differentiation and tooth root formation and may contribute to future therapeutic approaches to tooth root regeneration.展开更多
Background Individuals with type 2 diabetes mellitus(T2DM)are more vulnerable to social disconnection compared with the general population;however,there are few relevant studies investigating this issue.Aims To invest...Background Individuals with type 2 diabetes mellitus(T2DM)are more vulnerable to social disconnection compared with the general population;however,there are few relevant studies investigating this issue.Aims To investigate whether social isolation or loneliness may be associated with subsequent risk of developing major adverse cardiovascular events,whether these associations vary according to fatal and non-fatal outcomes and how behavioural,psychological and physiological factors mediate these associations.Methods This longitudinal analysis included data from 19360 individuals with T2DM at baseline(2006-2010)from the UK Biobank.Social isolation and loneliness were measured using self-report questionnaires.The study outcomes included the first events of myocardial infarction(MI)or stroke(n=2273)and all-cause(n=2820)or cardiovascular disease-related mortality through linked hospital data ordeath registries.Results Over a median follow-up of 12.4 years(interquartile range(IQR):11.6-13.3 years),participants who were more socially isolated(most social isolation vs least social isolation)experienced increased risks for all-cause(hazard ratio(HR):1.33,95%confidence interval(Cl):1.19 to 1.47)and cardiovascular disease(HR:1.36,95%Cl:1.17 to 1.59)mortality but not first Ml or stroke.Loneliness(yes vs no)was associated with a greater risk for a composite of incident MI or stroke(HR:1.37,95%Cl:1.19 to 1.57)but not mortality.Social isolation was associated with fatal Ml and stroke,whereas loneliness was associated with non-fatal Ml and stroke.The significant associations of social isolation and loneliness with outcomes were mainly mediated by behavioural factors(mediating proportion:17.8%-28.2%and 17.6%-17.8%,respectively).Conclusions Among individuals with T2DM,social isolation and loneliness are associated with a greater risk of developing major adverse cardiovascular events,with differences in both risks stratified according to fatal and non-fatal events and underlying mediating factors.展开更多
Gamma-aminobutyric acid(GABA)is a ubiquitous four-carbon non-protein amino acid that is involved in various physiological processes of plant growth and development,such as root architecture,stem elongation,leaf senesc...Gamma-aminobutyric acid(GABA)is a ubiquitous four-carbon non-protein amino acid that is involved in various physiological processes of plant growth and development,such as root architecture,stem elongation,leaf senescence,pollen tube growth,fruit ripening,and seed germination.GABA is also related to plant stress responses,such as drought,salt,cold,and heat stresses.Regulation of GABA in plant stress responses is complex and involves multiple signaling pathways,including calcium and hormone signaling.This paper systematically reviews the synthesis,metabolic pathways and regulatory role of GABA in plants,which will provide new insights into the understanding of plant growth and stress responses and offer novel strategies for improving crop productivity and stress.展开更多
For efficient solar energy conversion,the morphology engineering of hollow graphitic carbon nitride(gC3 N4)is one of the promising approachs benefiting from abundant exposed active sites and short photocarrier transpo...For efficient solar energy conversion,the morphology engineering of hollow graphitic carbon nitride(gC3 N4)is one of the promising approachs benefiting from abundant exposed active sites and short photocarrier transport distances,but is difficult to control on account of easy structural collapse.Herein,a facile supramolecular electrostatic self-assembly strategy has been developed for the first time to fabricate mesoporous thin-walled g-C3N4 microtubes(mtw-CNT)with shell thickness of ca.13 nm.The morphological control of g-C3N4 enhances specific surface area by 12 times,induces stronger optical absorption,widens bandgap by 0.18 e V,improves photocurrent density by 2.5 times,and prolongs lifetimes of charge carriers from bulk to surface,compared with those of bulk g-C3N4.As a consequence,the transformed g-C3N4 exhibits the optimum photocatalytic H2-production rate of 3.99 mmol·h^-1·g^-1(λ>420 nm)with remarkable apparent quantum efficiency of 8.7%(λ=420±15 nm)and long-term stability.Moreover,mtw-CNT also achieves high photocatalytic CO2-to-CO selectivity of 96%(λ>420 nm),much better than those on the most previously reported porous g-C3N4 photocatalysts prepared by the conventional hard-templating and soft-templating methods.展开更多
Semiconductor photocatalysis is a potential pathway to solve the problems of global energy shortage and environmental pollution.Black phosphorus(BP)has been widely used in the field of photocatalysis owing to its feat...Semiconductor photocatalysis is a potential pathway to solve the problems of global energy shortage and environmental pollution.Black phosphorus(BP)has been widely used in the field of photocatalysis owing to its features of high hole mobility,adjustable bandgap,and wide optical absorption range.Nevertheless,pristine BP still exhibits unsatisfactory photocatalytic activity due to the low separation efficiency of photoinduced charge carriers.In recent years,the construction of heterostructured photocatalysts based on BP has become a research hotspot in photocatalysis with the remarkable improvement of photoexcited charge-separation efficiency.Herein,progress on the design,synthesis,properties,and applications of BP and its corresponding heterostructured photocatalysts is summarized.Furthermore,the photocatalytic applications of BP-based heterostructured photocatalysts in water splitting,pollutant degradation,carbon dioxide reduction,nitrogen fixation,bacterial disinfection,and organic synthesis are reviewed.Opportunities and challenges for the exploration of advanced BP-based heterostructured photocatalysts are presented.This review will promote the development and applications of BP-based heterostructured photocatalysts in energy conversion and environmental remediation.展开更多
Putrescine(Put)as the compound of plant polyamines is catalyzed by arginine decarboxylase(ADC),which is encoded by two members,ADC1 and ADC2 in Arabidopsis,and ADC2 is mainly responsible for Put biosynthesis.Accumulat...Putrescine(Put)as the compound of plant polyamines is catalyzed by arginine decarboxylase(ADC),which is encoded by two members,ADC1 and ADC2 in Arabidopsis,and ADC2 is mainly responsible for Put biosynthesis.Accumulated evidence demonstrates the important function of Put in plant growth and development,but its role in regulating seed germination under high temperature(HT)has not been reported yet.SOMNUS(SOM)is the negative regulator for seed germination thermoinhibition by altering downstream gibberellin(GA)and abscisic acid(ABA)metabolism.In this study,we found exogenous application of Put obviously alleviated the inhibition effect of HT on seed germination.Whereas pharmacological inhibition of endogenous Put level reduced seed germination under HT.Consistently,HT induced the rapid accumulation of Put level,and the adc2 mutant defi-ciency in Put biosynthesis also showed more sensitivity to HT stress.Furthermore,we found that the Put signal suppressed the expression of SOM and changed the transcriptional patterns of genes associated with GA/ABA metabolism.Genetic analysis also revealed SOM was epistatic to ADC2 to alter GA/ABA metabolism.Collectively,our finding reveals the novel function of Put in controlling seed germination under HT through SOM,and provides the possibility to develop Put as the innovational regulator for uniform seed germination under HT stress.展开更多
Hardware/software partitioning is an essential step in hardware/software co-design.For large size problems,it is difficult to consider both solution quality and time.This paper presents an efficient GPU-based parallel...Hardware/software partitioning is an essential step in hardware/software co-design.For large size problems,it is difficult to consider both solution quality and time.This paper presents an efficient GPU-based parallel tabu search algorithm(GPTS)for HW/SW partitioning.A single GPU kernel of compacting neighborhood is proposed to reduce the amount of GPU global memory accesses theoretically.A kernel fusion strategy is further proposed to reduce the amount of GPU global memory accesses of GPTS.To further minimize the transfer overhead of GPTS between CPU and GPU,an optimized transfer strategy for GPU-based tabu evaluation is proposed,which considers that all the candidates do not satisfy the given constraint.Experiments show that GPTS outperforms state-of-the-art work of tabu search and is competitive with other methods for HW/SW partitioning.The proposed parallelization is significant when considering the ordinary GPU platform.展开更多
The synthesis of carbon onions in the laboratory by various methods is common;however, naturally occurring carbon onions have only been found in a few geological samples on Earth. This study used high-resolution trans...The synthesis of carbon onions in the laboratory by various methods is common;however, naturally occurring carbon onions have only been found in a few geological samples on Earth. This study used high-resolution transmission electron microscopy to identify natural carbon onions in seven intrusion-affected coal samples collected from Permian coal-bearing strata in the Yongan Coalfield, Fujian Province, South China. This study identified the largest natural carbon onions ever recorded on Earth;their outer diameter was ~55 nm. Granite porphyry intrusions and quartz hydrothermal veins are abundant in the Permian coal-bearing strata in this coalfield. All samples collected were tectonically deformed coals with highly developed structural fractures, friction mirror planes, and maximum vitrinite reflectance values of 4.0–9.5%. Natural carbon onions observed in the coal samples had single or multiple cores, with 24–46 graphitic shells characterized by outer diameters of 24–55 nm. The maximum vitrinite reflectance, outer diameter, and graphitic shell number of carbon onions in the intrusion-affected coal were positively correlated, indicating that the carbon onions were secondary products formed during coal metamorphism owing to magmatic intrusion. Our results suggest that carbon onions in intrusion-affected coal are synthesized by chemical vapor deposition. We speculate that natural carbon onions exist mainly in fractures or cavities, similar to vapor-deposited pyrolytic carbon, which is the leading cause of the uneven distribution of carbon onions in intrusion-affected coals in the study area.展开更多
A photocatalytic, intramolecular hydroalkoxylation of alkenes has been achieved by utilizing simple and readily available biphosphonium salts as an effective organic photocatalyst. The unique photocatalytic properties...A photocatalytic, intramolecular hydroalkoxylation of alkenes has been achieved by utilizing simple and readily available biphosphonium salts as an effective organic photocatalyst. The unique photocatalytic properties of biphosphonium salt enables facile oxidations of substituted alkenes to facilitate the streamline and regioselective synthesis of a series of saturated cyclic ethers from simple alkenes under mild conditions.展开更多
Chinese cooking features several unique processes,e.g.,stir-frying and pan-frying,which represent important sources of household air pollution.However,factors affecting household air pollution and the vertical variati...Chinese cooking features several unique processes,e.g.,stir-frying and pan-frying,which represent important sources of household air pollution.However,factors affecting household air pollution and the vertical variations of indoor pollutants during Chinese cooking are less clear.Here,using low-cost sensors with high time resolutions,we measured concentrations of five gas species and particulate matter(PM)in three different sizes at multiple heights in a kitchen during eighteen different Chinese cooking events.We found indoor gas species were elevated by 21%-106%during cooking,compared to the background,and PMs were elevated by 44%-159%.Vertically,the pollutants concentrations were highly variable during cooking periods.Gas species generally showed a monotonic increase with height,while PMs changed more diversely depending on the cooking activity's intensity.Intense cooking,e.g.,stir-frying,pan-frying,or cooking on high heat,tended to shoot PMs to the upper layers,while moderate ones left PMs within the breathing zone.Individuals with different heights would be subject to different levels of household air pollution exposure during cooking.The high vertical variability challenges the current indoor standard that presumes a uniform pollution level within the breathing zone and thus has important implications for public health and policy making.展开更多
基金supported by the National Key R&D Program of China(2021YFC2501500)National Natural Science Foundation of China(82171476)。
文摘Purpose:The aim of the current study was to investigate the association of accelerometer-measured sleep duration and different intensities of physical activity(PA)with the risk of incident type 2 diabetes in a population-based prospective cohort study.Methods:Altogether,88,000 participants(mean age=62.2±7.9 years,mean±SD)were included from the UK Biobank.Sleep duration(short:<6 h/day;normal:6-8 h/day;long:>8 h/day)and PA of different intensities were measured using a wrist-won accelerometer over a 7-day period between 2013 and 2015.PA was classified according to the median or World Health Organization-recommendation:total volume of PA(high,low),moderate-to-vigorous PA(MVPA)(recommended,not recommended),and light-intensity PA(high,low).Incidence of type 2diabetes was ascertained using hospital records or death registries.Results:During a median follow-up of 7.0 years,1615 incident type 2 diabetes cases were documented.Compared with normal sleep duration,short(hazard ratio(HR)=1.21,95%confidence interval(95%CI):1.03-1.41)but not long sleep duration(HR=1.01,95%CI:0.89-1.15)was associated with excessive type 2 diabetes risk.This increased risk among short sleepers seems to be protected against by PA.Compared with normal sleepers with high or recommended PA,short sleepers with low volume of PA(HR=1.81,95%CI:1.46-2.25),not recommended(below the World Health Organization-recommended level of)MVPA(HR=1.92,95%CI:1.55-2.36),or low light-intensity PA(HR=1.49,95%CI:1.13-1.90)had a higher risk of type 2 diabetes,while short sleepers with a high volume of PA(HR=1.14,95%CI:0.88-1.49),recommended MVPA(HR=1.02,95%CI:0.71-1.48),or high light-intensity PA(HR=1.14,95%CI:0.92-1.41)did not.Conclusion:Accelerometer-measured short but not long sleep duration was associated with a higher risk of incident type 2 diabetes.A higher level of PA,regardless of intensity,potentially ameliorates this excessive risk.
基金Project supported by the National Key Research and Development Project of China (Grant No.2021YFB3602404)part by the National Natural Science Foundation of China (Grant Nos.61904135 and 62234009)+4 种基金the Key R&D Program of Guangzhou (Grant No.202103020002)Wuhu and Xidian University special fund for industry-university-research cooperation (Grant No.XWYCXY-012021014-HT)the Fundamental Research Funds for the Central Universities (Grant No.XJS221110)the Natural Science Foundation of Shaanxi,China (Grant No.2022JM-377)the Innovation Fund of Xidian University (Grant No.YJSJ23019)。
文摘Improved radio-frequency(RF)power performance of InAlN/GaN high electron mobility transistor(HEMT)is achieved by optimizing the rapid thermal annealing(RTA)process for high-performance low-voltage terminal applications.By optimizing the RTA temperature and time,the optimal annealing condition is found to enable low parasitic resistance and thus a high-performance device.Besides,compared with the non-optimized RTA HEMT,the optimized one demonstrates smoother ohmic metal surface morphology and better heterojunction quality including the less degraded heterojunction sheet resistance and clearer heterojunction interfaces as well as negligible material out-diffusion from the barrier to the channel and buffer.Benefiting from the lowered parasitic resistance,improved maximum output current density of 2279 mA·mm^(-1)and higher peak extrinsic transconductance of 526 mS·mm^(-1)are obtained for the optimized RTA HEMT.In addition,due to the superior heterojunction quality,the optimized HEMT shows reduced off-state leakage current of 7×10^(-3)mA·mm^(-1)and suppressed current collapse of only 4%,compared with those of 1×10^(-1)mA·mm^(-1)and 15%for the non-optimized one.At 8 GHz and V_(DS)of 6 V,a significantly improved power-added efficiency of 62%and output power density of 0.71 W·mm^(-1)are achieved for the optimized HEMT,as the result of the improvement in output current,knee voltage,off-state leakage current,and current collapse,which reveals the tremendous advantage of the optimized RTA HEMT in high-performance low-voltage terminal applications.
基金supported by the National Institutes of Health[DE023813 and DE028264 to Y.P.L.,and AG056438 and AR070135 to W.C.]the UAB National Institutes of Health National Institute of Dental and Craniofacial Research[Dental Academic Research Training Grant(DART)5T90DE022736 to J.W.].
文摘The biomolecular mechanisms that regulate tooth root development and odontoblast differentiation are poorly understood.We found that Atp6i deficient mice(Atp6i^(−/−))arrested tooth root formation,indicated by truncated Hertwig’s epithelial root sheath(HERS)progression.Furthermore,Atp6i deficiency significantly reduced the proliferation and differentiation of radicular odontogenic cells responsible for root formation.Atp6i^(−/−)mice had largely decreased expression of odontoblast differentiation marker gene expression profiles(Col1a1,Nfic,Dspp,and Osx)in the alveolar bone.Atp6i^(−/−)mice sample RNA-seq analysis results showed decreased expression levels of odontoblast markers.Additionally,there was a significant reduction in Smad2/3 activation,inhibiting transforming growth factor-β(TGF-β)signaling in Atp6i^(−/−)odontoblasts.Through treating pulp precursor cells with Atp6i^(−/−)or wild-type OC bone resorption-conditioned medium,we found the latter medium to promote odontoblast differentiation,as shown by increased odontoblast differentiation marker genes expression(Nfic,Dspp,Osx,and Runx2).This increased expression was significantly blocked by anti-TGF-β1 antibody neutralization,whereas odontoblast differentiation and Smad2/3 activation were significantly attenuated by Atp6i^(−/−)OC conditioned medium.Importantly,ectopic TGF-β1 partially rescued root development and root dentin deposition of Atp6i^(−/−)mice tooth germs were transplanted under mouse kidney capsules.Collectively,our novel data shows that the prevention of TGF-β1 release from the alveolar bone matrix due to OC dysfunction may lead to osteopetrosis-associated root formation via impaired radicular odontoblast differentiation.As such,this study uncovers TGF-β1/Smad2/3 as a key signaling pathway regulating odontoblast differentiation and tooth root formation and may contribute to future therapeutic approaches to tooth root regeneration.
基金funded by the National Natural Science Foundation of China(32100880)Guangzhou Municipal Key Discipline in Medicine(2021-2023)Guangzhou High-level Clinical Key Specialty and Guangzhou Research-oriented Hospital.
文摘Background Individuals with type 2 diabetes mellitus(T2DM)are more vulnerable to social disconnection compared with the general population;however,there are few relevant studies investigating this issue.Aims To investigate whether social isolation or loneliness may be associated with subsequent risk of developing major adverse cardiovascular events,whether these associations vary according to fatal and non-fatal outcomes and how behavioural,psychological and physiological factors mediate these associations.Methods This longitudinal analysis included data from 19360 individuals with T2DM at baseline(2006-2010)from the UK Biobank.Social isolation and loneliness were measured using self-report questionnaires.The study outcomes included the first events of myocardial infarction(MI)or stroke(n=2273)and all-cause(n=2820)or cardiovascular disease-related mortality through linked hospital data ordeath registries.Results Over a median follow-up of 12.4 years(interquartile range(IQR):11.6-13.3 years),participants who were more socially isolated(most social isolation vs least social isolation)experienced increased risks for all-cause(hazard ratio(HR):1.33,95%confidence interval(Cl):1.19 to 1.47)and cardiovascular disease(HR:1.36,95%Cl:1.17 to 1.59)mortality but not first Ml or stroke.Loneliness(yes vs no)was associated with a greater risk for a composite of incident MI or stroke(HR:1.37,95%Cl:1.19 to 1.57)but not mortality.Social isolation was associated with fatal Ml and stroke,whereas loneliness was associated with non-fatal Ml and stroke.The significant associations of social isolation and loneliness with outcomes were mainly mediated by behavioural factors(mediating proportion:17.8%-28.2%and 17.6%-17.8%,respectively).Conclusions Among individuals with T2DM,social isolation and loneliness are associated with a greater risk of developing major adverse cardiovascular events,with differences in both risks stratified according to fatal and non-fatal events and underlying mediating factors.
基金supported by Start-Up Funding from Shanghai University and the National Natural Science Foundation of China(Grant No.31970289).
文摘Gamma-aminobutyric acid(GABA)is a ubiquitous four-carbon non-protein amino acid that is involved in various physiological processes of plant growth and development,such as root architecture,stem elongation,leaf senescence,pollen tube growth,fruit ripening,and seed germination.GABA is also related to plant stress responses,such as drought,salt,cold,and heat stresses.Regulation of GABA in plant stress responses is complex and involves multiple signaling pathways,including calcium and hormone signaling.This paper systematically reviews the synthesis,metabolic pathways and regulatory role of GABA in plants,which will provide new insights into the understanding of plant growth and stress responses and offer novel strategies for improving crop productivity and stress.
基金financially supported by the National Natural Science Foundation of China(21902051)the Natural Science Foundation of Fujian Province(2017J01014 and 2019J05090)the Graphene Power and Composite Research Center of Fujian Province(2017H2001)。
文摘For efficient solar energy conversion,the morphology engineering of hollow graphitic carbon nitride(gC3 N4)is one of the promising approachs benefiting from abundant exposed active sites and short photocarrier transport distances,but is difficult to control on account of easy structural collapse.Herein,a facile supramolecular electrostatic self-assembly strategy has been developed for the first time to fabricate mesoporous thin-walled g-C3N4 microtubes(mtw-CNT)with shell thickness of ca.13 nm.The morphological control of g-C3N4 enhances specific surface area by 12 times,induces stronger optical absorption,widens bandgap by 0.18 e V,improves photocurrent density by 2.5 times,and prolongs lifetimes of charge carriers from bulk to surface,compared with those of bulk g-C3N4.As a consequence,the transformed g-C3N4 exhibits the optimum photocatalytic H2-production rate of 3.99 mmol·h^-1·g^-1(λ>420 nm)with remarkable apparent quantum efficiency of 8.7%(λ=420±15 nm)and long-term stability.Moreover,mtw-CNT also achieves high photocatalytic CO2-to-CO selectivity of 96%(λ>420 nm),much better than those on the most previously reported porous g-C3N4 photocatalysts prepared by the conventional hard-templating and soft-templating methods.
基金financially supported by the National Natural Science Foundation of China(21902051,21861130353,U1905214,21961142019,22032002,21761132002,and 21425309)the Fundamental Research Funds for the Central Universities(ZQN-807)+7 种基金the Natural Science Foundation of Fujian Province(2019J05090 and 2017J01014)the Graphene Powder and Composite Research Center of Fujian Province(2017H2001)the Scientific Research Funds of Huaqiao University(20171XD033)the Open Project Program of the State Key Laboratory of Photocatalysis on Energy and Environment of Fuzhou University(SKLPEE-KF201803)the National Key Technologies R&D Program of China(2018YFA0209301)the National Basic Research Program of China(2013CB632405)the Chang Jiang Scholars Program of China(T2016147)the 111 Project(D16008).
文摘Semiconductor photocatalysis is a potential pathway to solve the problems of global energy shortage and environmental pollution.Black phosphorus(BP)has been widely used in the field of photocatalysis owing to its features of high hole mobility,adjustable bandgap,and wide optical absorption range.Nevertheless,pristine BP still exhibits unsatisfactory photocatalytic activity due to the low separation efficiency of photoinduced charge carriers.In recent years,the construction of heterostructured photocatalysts based on BP has become a research hotspot in photocatalysis with the remarkable improvement of photoexcited charge-separation efficiency.Herein,progress on the design,synthesis,properties,and applications of BP and its corresponding heterostructured photocatalysts is summarized.Furthermore,the photocatalytic applications of BP-based heterostructured photocatalysts in water splitting,pollutant degradation,carbon dioxide reduction,nitrogen fixation,bacterial disinfection,and organic synthesis are reviewed.Opportunities and challenges for the exploration of advanced BP-based heterostructured photocatalysts are presented.This review will promote the development and applications of BP-based heterostructured photocatalysts in energy conversion and environmental remediation.
基金the National Natural Science Foundation of China(Grant No.32170562).
文摘Putrescine(Put)as the compound of plant polyamines is catalyzed by arginine decarboxylase(ADC),which is encoded by two members,ADC1 and ADC2 in Arabidopsis,and ADC2 is mainly responsible for Put biosynthesis.Accumulated evidence demonstrates the important function of Put in plant growth and development,but its role in regulating seed germination under high temperature(HT)has not been reported yet.SOMNUS(SOM)is the negative regulator for seed germination thermoinhibition by altering downstream gibberellin(GA)and abscisic acid(ABA)metabolism.In this study,we found exogenous application of Put obviously alleviated the inhibition effect of HT on seed germination.Whereas pharmacological inhibition of endogenous Put level reduced seed germination under HT.Consistently,HT induced the rapid accumulation of Put level,and the adc2 mutant defi-ciency in Put biosynthesis also showed more sensitivity to HT stress.Furthermore,we found that the Put signal suppressed the expression of SOM and changed the transcriptional patterns of genes associated with GA/ABA metabolism.Genetic analysis also revealed SOM was epistatic to ADC2 to alter GA/ABA metabolism.Collectively,our finding reveals the novel function of Put in controlling seed germination under HT through SOM,and provides the possibility to develop Put as the innovational regulator for uniform seed germination under HT stress.
基金This paper was supported by the National Natural Science Foundation of China(Grant No.61472289)National Key Research and Development Project(2016YFC0106305).We also would like to thank the anonymous reviewers for their valuable and constructive comments.
文摘Hardware/software partitioning is an essential step in hardware/software co-design.For large size problems,it is difficult to consider both solution quality and time.This paper presents an efficient GPU-based parallel tabu search algorithm(GPTS)for HW/SW partitioning.A single GPU kernel of compacting neighborhood is proposed to reduce the amount of GPU global memory accesses theoretically.A kernel fusion strategy is further proposed to reduce the amount of GPU global memory accesses of GPTS.To further minimize the transfer overhead of GPTS between CPU and GPU,an optimized transfer strategy for GPU-based tabu evaluation is proposed,which considers that all the candidates do not satisfy the given constraint.Experiments show that GPTS outperforms state-of-the-art work of tabu search and is competitive with other methods for HW/SW partitioning.The proposed parallelization is significant when considering the ordinary GPU platform.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 42130802 and 41972176)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘The synthesis of carbon onions in the laboratory by various methods is common;however, naturally occurring carbon onions have only been found in a few geological samples on Earth. This study used high-resolution transmission electron microscopy to identify natural carbon onions in seven intrusion-affected coal samples collected from Permian coal-bearing strata in the Yongan Coalfield, Fujian Province, South China. This study identified the largest natural carbon onions ever recorded on Earth;their outer diameter was ~55 nm. Granite porphyry intrusions and quartz hydrothermal veins are abundant in the Permian coal-bearing strata in this coalfield. All samples collected were tectonically deformed coals with highly developed structural fractures, friction mirror planes, and maximum vitrinite reflectance values of 4.0–9.5%. Natural carbon onions observed in the coal samples had single or multiple cores, with 24–46 graphitic shells characterized by outer diameters of 24–55 nm. The maximum vitrinite reflectance, outer diameter, and graphitic shell number of carbon onions in the intrusion-affected coal were positively correlated, indicating that the carbon onions were secondary products formed during coal metamorphism owing to magmatic intrusion. Our results suggest that carbon onions in intrusion-affected coal are synthesized by chemical vapor deposition. We speculate that natural carbon onions exist mainly in fractures or cavities, similar to vapor-deposited pyrolytic carbon, which is the leading cause of the uneven distribution of carbon onions in intrusion-affected coals in the study area.
基金supported by the National Natural Science Foundation of China (21702029,21772121)
文摘A photocatalytic, intramolecular hydroalkoxylation of alkenes has been achieved by utilizing simple and readily available biphosphonium salts as an effective organic photocatalyst. The unique photocatalytic properties of biphosphonium salt enables facile oxidations of substituted alkenes to facilitate the streamline and regioselective synthesis of a series of saturated cyclic ethers from simple alkenes under mild conditions.
基金supported by the National Natural Science Foundation of China(Grants 41991312,41821005,41922057,41830641,and 42192510)Shenzhen Environmental Monitoring Center(Grant 0722-216FE4812SZF-2)+1 种基金Department of Education of Guangdong Province(2021KCXTD004)Center for Computational Science and Engineering at Southern University of Science and Technology.
文摘Chinese cooking features several unique processes,e.g.,stir-frying and pan-frying,which represent important sources of household air pollution.However,factors affecting household air pollution and the vertical variations of indoor pollutants during Chinese cooking are less clear.Here,using low-cost sensors with high time resolutions,we measured concentrations of five gas species and particulate matter(PM)in three different sizes at multiple heights in a kitchen during eighteen different Chinese cooking events.We found indoor gas species were elevated by 21%-106%during cooking,compared to the background,and PMs were elevated by 44%-159%.Vertically,the pollutants concentrations were highly variable during cooking periods.Gas species generally showed a monotonic increase with height,while PMs changed more diversely depending on the cooking activity's intensity.Intense cooking,e.g.,stir-frying,pan-frying,or cooking on high heat,tended to shoot PMs to the upper layers,while moderate ones left PMs within the breathing zone.Individuals with different heights would be subject to different levels of household air pollution exposure during cooking.The high vertical variability challenges the current indoor standard that presumes a uniform pollution level within the breathing zone and thus has important implications for public health and policy making.
