A glacier hazard chain can form a long-runout mass flow and generate a large flood,affecting downstream areas hundreds of kilometers away from the initiating hazard site.This study focuses on the Yarlung Zangbo Daxiag...A glacier hazard chain can form a long-runout mass flow and generate a large flood,affecting downstream areas hundreds of kilometers away from the initiating hazard site.This study focuses on the Yarlung Zangbo Daxiagu.The objective is to address two key unresolved issues:the evolution of detached glacier materials into debris flows or debris floods and the amplification of the impact range and threats.A comprehensive framework is developed that considers the impacts of near-field and far-field hazards.Numerical modeling,remote sensing,and field investigations were integrated to understand the interactions,transformations,and amplifications of hazards in the glacier hazard chain.The results indicate that extensive,nearly saturated sediments on the glacier valley floor,when entrained,amplify the magnitude of the mass flow.The topography plays a crucial role.When the valley outlet is perpendicular to the river course,topographic obstacles cause immediate halting,resulting in the formation of high barrier dams.Conversely,when the glacier valley aligns nearly parallel to the river course,the mass flow can travel a much longer distance upon entering the river,causing an enlarged affected area.The barrier dams can breach rapidly,causing breaching floods that amplify the downstream impact from several kilometers to hundreds of kilometers.Our analysis reveals that the overall impacts remain spatially limited.Specifically,downstream areas along the Yarlung Zangbo-Brahmaputra River are unlikely to face greater threats from the upstream floods than local monsoon floods.Our findings provide the foundation for the management of glacier hazard chains.展开更多
Water stress is expected to intensify due to escalating atmospheric and surface dryness under global warming.Despite extensive research indicate that intensified dryness exacerbates water constraints on ecosystems,the...Water stress is expected to intensify due to escalating atmospheric and surface dryness under global warming.Despite extensive research indicate that intensified dryness exacerbates water constraints on ecosystems,the dynamics and underlying mechanisms of surface water stress(SWS)under climate change remain poorly understood.In this study,we use annual evaporative stress as the surface water stress index(WSI)and provide a comprehensive analysis of historical and projected global terrestrial SWS,covering its characteristic changes,driving factors,and impacts on vegetation.Our results show a significant declining trend in WSI during 1982–2014(-0.0033/decade,p<0.01),indicating the enhancement of SWS concurrent with a rapid expansion of water stress intensified areas at a rate of 1.85%/decade(p<0.01).Using the Budyko-Penman budget framework,we found that the intensification of SWS was primarily driven by an increase in vapor pressure deficit(VPD)and a decrease in precipitation.Furthermore,the intensification of SWS contributed to a decline in vegetation growth,with the extent of areas experiencing increased vegetation water deficit expanding rapidly at a rate of 1.38%per decade(p<0.01).In the future,SWS is projected to escalate,with the proportion of areas experiencing intensified SWS increasing from 6.3%to 24.3%by the end of the century under the SSP5–8.5.Our study provides a comprehensive analysis of the drivers of SWS under climate change and its impacts on ecosystems,offering valuable scientific insights for the effective management of water resources.展开更多
Drought stress impairs plant growth and other physiological functions. MeHDZ14, a homeodomainleucine zipper I transcription factor, is strongly induced by drought stress in various cassava cultivars.However, the role ...Drought stress impairs plant growth and other physiological functions. MeHDZ14, a homeodomainleucine zipper I transcription factor, is strongly induced by drought stress in various cassava cultivars.However, the role of MeHDZ14 in cassava growth regulation has remained unclear. Here we report that MeHDZ14 affected plant height, such that a dwarf phenotype and altered internode elongation were observed in transgenic cassava lines. MeHDZ14 was found to negatively regulate the biosynthesis of lignin. Its overexpression resulted in abaxially rolled leaves. The morphogenesis of leaf epidermal cells was inhibited by overexpression of MeHDZ14, with decreased auxin and gibberellin and increased cytokinin contents. MeHDZ14 was found to regulate many drought-responsive genes, including genes involved in cell wall synthesis and expansion. MeHDZ14 bound to the promoter of caffeic acid 3-Omethyltransferase 1(MeCOMT1), acting as a transcriptional repressor of genes involved in cell wall development. MeHDZ14 appears to act as a negative regulator of internode elongation and epidermal cell morphogenesis during cassava leaf development.展开更多
Chilling-induced accumulation of reactive oxygen species(ROS) is harmful to plants,which usually produce anthocyanins to scavenge ROS as protection from chilling stress.As a tropical crop,cassava is hypersensitive to ...Chilling-induced accumulation of reactive oxygen species(ROS) is harmful to plants,which usually produce anthocyanins to scavenge ROS as protection from chilling stress.As a tropical crop,cassava is hypersensitive to chilling,but the biochemical basis of this hypersensitivity remains unclear.We previously generated Me MYB2-RNAi transgenic cassava with increased chilling tolerance.Here we report that Me MYB2-RNAi transgenic cassava accumulated less ROS but more cyanidin-3-O-glucoside than the wild type under early chilling stress.Under this stress,the anthocyanin biosynthesis pathway was more active in Me MYB2-RNAi lines than in the wild type,and several genes involved in the pathway,including Me TT8,were up-regulated by Me MYB2-RNAi in the transgenic cassava.Me MYB2 bound to the Me TT8 promoter and blocked its expression under both normal and chilling conditions,thereby inhibiting anthocyanin accumulation.Me TT8 was shown to bind to the promoter of Dihydroflavonol 4-reductase(Me DFR-2)and increased Me DFR-2 expression.Me MYB2 appears to act as an inhibitor of chilling-induced anthocyanin accumulation during the rapid response of cassava to chilling stress.展开更多
Vegetation greening has long been acknowledged,but recent studies have pointed out that vegetation greening is possibly stalled or even reversed.However,detailed analyses about greening reversal or increased browning ...Vegetation greening has long been acknowledged,but recent studies have pointed out that vegetation greening is possibly stalled or even reversed.However,detailed analyses about greening reversal or increased browning of vegetation remain scarce.In this study,we utilized the normalized difference vegetation index(NDVI)as an indicator of vegetation to investigate the trends of vegetation greening and browning(monotonic,interruption,and reversal)through the breaks for the additive season and trend(BFAST)method across China’s drylands from 1982 to 2022.It also reveals the impacts of ecological restoration programs(ERPs)and climate change on these vegetation trends.We find that the vegetation displays an obvious pattern of east-greening and west-browning in China’s drylands.Greening trends mainly exhibits monotonic greening(29.8%)and greening with setback(36.8%),whereas browning shows a greening to browning reversal(19.2%).The increase rate of greening to browning reversal is 0.0342/yr,which is apparently greater than that of greening with setback,0.0078/yr.This research highlights that,under the background of widespread vegetation greening,vegetation browning is pro-gressively increasing due to the effects of climate change.Furthermore,the ERPs have significantly increased vegetation coverage,with the increase rate in 2000-2022 being twice as much as that of 1982-1999 in reveg-etation regions.Vegetation browning in southwestern Qingzang Plateau is primarily driven by adverse climatic factors and anthropogenic disturbances,which offset the efforts of ERPs.展开更多
Locoweed is a poisonous plant that severely harms the development of grass-land and animal husbandry throughout the world. Oxytropis and Astragalus are the Latin names for the poisonous plants commonly known as locowe...Locoweed is a poisonous plant that severely harms the development of grass-land and animal husbandry throughout the world. Oxytropis and Astragalus are the Latin names for the poisonous plants commonly known as locoweed. The main toxic substance in these plants is swainsonine. It is a strong inhibitor of lysosomal α-mannosidase I and Golgi body α-mannosidase II, resulting in the accumulation of oligosaccharides and glycoproteins in lysosomes, interfering with the molecular and cellular recognition of glycans, and causing tissue-cell vacuolar degeneration. Livestock shows a series of clinical and pathological symptoms, mainly for the decline of reproductive performance. The effects in dams are abortion, weak fetus, and fetal malformations. The key step in maintaining pregnancy in dams is early endometrial decidualization, because reproductive hormones, decidual cell apoptosis, endoplasmic reticulum (ER) stress, and other immune factors are negatively affected by swainsonine. This article addresses the modifications that occur through glycan processing and glycosylation resulting in the change of post-translational modification of the protein and the activity of the glycoprotein, and then direct and indirect mechanisms of ER stress, apoptosis, reproductive hormones, immune factors, and cell cycle and other pathways. Our aim is to find new methods of prevention and treatment of swainsonine poisoning in grassland animals.展开更多
As the development of smart electronics, self-powered sources have been attracting increasing attention.This review summarizes research progress of photovoltaic fibers and their integrated power sources with multi-sta...As the development of smart electronics, self-powered sources have been attracting increasing attention.This review summarizes research progress of photovoltaic fibers and their integrated power sources with multi-stage energy conversion. Recent development of three dimensional photovoltaic fibers is glanced with special attention to structure design and materials of typical photovoltaic types（inorganic, organic,dye/quantum dot sensitized and perovskite solar cells）. The application of carbon materials in fiber energy is focused as it is a hot topic recently. The hybrid energy systems based on fiber solar cells and fiber supercapacitors, fiber batteries and fiber nanogenerators are summarized together with hybrid energy textiles. This review provides a macroscopic view of novel energy fibers and will attract research interest in flexible/wearable fiber electronics and energy textiles.展开更多
The hybrid battery integrating a typical Zn redox battery and a Zn-air battery is a promising green technology for energy storage,and the cathode integrating the redox reaction and electrocatalytic oxygen reduction is...The hybrid battery integrating a typical Zn redox battery and a Zn-air battery is a promising green technology for energy storage,and the cathode integrating the redox reaction and electrocatalytic oxygen reduction is a key point for efficient electrochemical energy conversion.Herein,we report a scalable strategy to fabricate nanoporous Ag2 Al internetallic compound as a self-standing cathode for the hybrid Zn battery.The abundant surface oxygen species,the Ag-Al intermetallic interaction and the npAg_(2)Al@AgAlOx interface cooperatively contributed to the catalytic ORR activity.The electrode endows efficient catalytic oxygen reduction(a Tafel slope of 38.0 mV/dec and an onset potential of 0.998 V)and regulated redox activity as compared with Ag.The nanoporous channels allow efficient ion transport,interface charge exchange and gas molecular diffusion.Significantly,the assembled hybrid Zn-Ag_(2) Al/air battery delivers a high capacity of 3.23 mAh/cm^(2) as compared with recent reports.As far as we know,this is the first exploration for the electrochemical property of Ag2 Al,and it would inspire more exploration in developing multifunctional materials and robust hybrid batteries for practical applications.展开更多
Objective:To investigate the effects of sevoflurane inhalation general anesthesia on serum IL-6,brain injury protein S100βand coagulation function in elderly patients undergoing total hip arthroplasty.Method:From May...Objective:To investigate the effects of sevoflurane inhalation general anesthesia on serum IL-6,brain injury protein S100βand coagulation function in elderly patients undergoing total hip arthroplasty.Method:From May 2017 to May 2019,84 patients,age 60-75 underwent total hip arthroplasty in our hospital.were randomly divided into two groups:group A(n=42)and group B(n=42).Group A was maintained with sevoflurane inhalation by general anesthesia and group B with propofol by intravenous anesthesia.The surgical related indexes and postoperative complications in the two groups were compared.The level of serum IL-6,S100β,Coagulation function index[platelet count(PLT),Fibrinogen(FIB),plasma D-dimer(D-D),activated partial enzyme activity time(APTT),prothrombin time(PT)],MMSE score and MoCA score were compared between two groups before and after operation.Results:There was no significant difference in anesthesia time,operation time,intraoperative bleeding and postoperative drainage(P>0.05).1h,1d and 7d after operation,the level of PLT,D-D and FIB in group A were significantly lower than that in group B(P<0.05),PT and APTT were significantly higher than that in group B(P<0.05).1h,1d and 7d after operation,the level of IL-6,S100βin group A were significantly lower than that in group B(P<0.05).1d after operation,the MMSE and MoCA scores in group B were significantly lower than those in group A(P<0.05).The incidence of lower extremity deep venous thrombosis(2.38%)and cognitive impairment(2.38%)in group A was lower than that in group B(14.29%,16.67%)(t1=3.896,P1=0.048;t2=4.974,P2=0.026).Conclusion:sevoflurane anesthesia can reduce the incidence of deep venous thrombosis and cognitive impairment of the lower extremity after operation in elderly patients with thr,stabilize the coagulation index of patients,and downregulate the expression of il-6 and S100β.展开更多
With the rise of artificial intelligence and the rapid development of industrial applications based on deep learning,the demand for innovative and practical talents is rapidly increased.The cultivation of talents in c...With the rise of artificial intelligence and the rapid development of industrial applications based on deep learning,the demand for innovative and practical talents is rapidly increased.The cultivation of talents in computer discipline has attracted a lot of attention from universities,research institutions,and Internet giants.Subject contests play a crucial role in cultivating top undergraduate talents.This paper proposes a cultivation model that takes the industry application of deep learning as the background,and guides students to learn,practice,and innovate incrementally from machine learning application to deep learning application by participating in subject contests.It aims to help undergraduates to master the cutting-edge technologies and applications,and ultimately cultivate top,innovative,and practical undergraduate talents in the computer field in the era of artificial intelligence.展开更多
[ Objective ] This study aimed to identify a cellulase-producing strain selected from tropical rain forestry soils. [ Method ] Morphologic observation and sequence analysis of 18S rDNA were conducted. [Result] A cellu...[ Objective ] This study aimed to identify a cellulase-producing strain selected from tropical rain forestry soils. [ Method ] Morphologic observation and sequence analysis of 18S rDNA were conducted. [Result] A cellulase-preducing strain with high activity was obtained, and morphology of the strain was highly similar to that of Trichoderma reesei. Results of sequence analysis show that the 18S rDNA sequence shares 99% homology with Hypocreajecorina. [ Conclusion] The isolated cellulase-producing strain belongs to Trichoderma reesei.展开更多
Cassava(Manihot esculenta Crantz)is a root crop significant in food security and various bio-industrial applications such as animal feed,modified starch,and biofuels.Drought and cold stress are two major factors limit...Cassava(Manihot esculenta Crantz)is a root crop significant in food security and various bio-industrial applications such as animal feed,modified starch,and biofuels.Drought and cold stress are two major factors limiting cassava production qualitatively and quantitatively,for which plants have evolved mechanisms to overcome the impact of these two stressors.In recent years,significant progress has been achieved in understanding the response mechanism of cassava plants to stress signals to tolerate the above stresses.In this review,core stress-signaling pathways,including transcription factor(TF)-related regulatory networks,plant hormone signaling,reactive oxygen species(ROS)scavenging,and non-coding RNA(ncRNA)and alternative splicing(AS)that modify gene expression levels in response to drought and/or cold stress in cassava,are summarized.Understanding these stress signaling and responses will increase our ability to improve the crops tolerance to multiple stresses for agricultural sustainability and food security for the growing world population.展开更多
Cassava is a highly resilient tropical crop that produces large,starchy storage roots and high biomass.However,how did cassava’s remarkable environmental adaptability and key economic traits evolve from its wild spec...Cassava is a highly resilient tropical crop that produces large,starchy storage roots and high biomass.However,how did cassava’s remarkable environmental adaptability and key economic traits evolve from its wild species remain unclear.In this study,we obtained near complete telomere-to-telomere genome assemblies and their haplotype forms for the cultivar AM560,the wild ancestors FLA4047 and W14,constructed a graphic pan-genome of 30 representatives with a size of 1.15 Gb,and built a clarified evolutionary tree of 486 accessions.A comparison of structural variations and single-nucleotide variations between the ancestors and cultivated cassavas reveals predominant expansions and contractions of numbers of genes and gene families,which are mainly driven by transposons.Significant selective sweeping occurred in 122 footprints of genomes and affects 1,519 domesticated genes.We identify selective mutations in MeCSK and MeFNR2 that could promote photoreactions associated with MeNADP-ME in C4 photosynthesis in modern cassava.Coevolution of retard floral primordia and initiation of storage roots may arise from MeCOL5 variants with altered bindings to MeFT1,MeFT2,and MeTFL2.Mutations in MeMATE1 and MeGTR occur in sweet cassava,and MeAHL19 has evolved to regulate the biosynthesis,transport,and endogenous remobilization of cyanogenic glucosides in cassava.These extensive genomic and gene resources provided here,along with the findings on the evolutionary mechanisms responsible for beneficial traits in modern cultivars,lay a strong foundation for future breeding improvements of cassava.展开更多
To solve the problem of field waterlogging during wheat sowing in rice-wheat rotation areas,which causes sticky and wet soil,thus affecting the growth of wheat,this paper proposed a sloped ditching method based on las...To solve the problem of field waterlogging during wheat sowing in rice-wheat rotation areas,which causes sticky and wet soil,thus affecting the growth of wheat,this paper proposed a sloped ditching method based on laser alignment technology,and designed a combined ditching device with a front ditching shovel(FDS)and a rear ditching plow(RDP)to create sloped drainage furrows when sowing wheat.The key factors affecting the performance of RDP and value ranges were determined through theoretical analysis.Through discrete element method(DEM)simulation,the influence of different structural parameter combinations on slope stability was studied,and the optimal parameter combination was determined as the soil lifting angle of 50°,the minimum element angle of 35°,and the maximum element angle of 40°.The field test showed that the ditching device can effectively create sloped trapezoidal drainage furrows.The slope stability coefficient and slope accuracy coefficient were both greater than 85%,which meets the requirements of drainage.This paper provides a new ditching method and theoretical basis for the development of a sowing and ditching combined machine in rice stubble fields.展开更多
Free trans-4-hydroxy-L-proline(T4LHyp),a non-proteinogenic amino acid,is mainly released from the degradation of collagen,hydroxyproline-rich glycoproteins,and some peptide antibiotics in nature.Although it has been k...Free trans-4-hydroxy-L-proline(T4LHyp),a non-proteinogenic amino acid,is mainly released from the degradation of collagen,hydroxyproline-rich glycoproteins,and some peptide antibiotics in nature.Although it has been known that some terrestrial bacteria utilize T4LHyp as carbon and nitrogen source via a T4LHyp gene cluster,which and how marine micro-organisms catabolize T4LHyp still remains unclear.Here,five T4LHyp-utilizing marine bacterial strains,Halomonas sp.5021,Salinicola sp.4072,Alteromonas sp.6022,Alteromonas sp.5112 and Alteromonas sp.30521,were isolated from hydrothermal vent sediment samples collected from the southwest Indian Ocean.While Halomonas sp.5021 can utilize T4LHyp as both a nitrogen and carbon source,the other four strains can utilize T4LHyp as only a nitrogen source.Then,the T4LHyp catabolic mechanisms of Halomonas sp.5021 and Salinicola sp.4072,as a representative of the four strains,were further investigated by genomic,transcriptional,and biochemical analyses.Halomonas sp.5021 adopts an intact T4LHyp gene cluster containing four enzymes to catabolize T4LHyp into NH3 andα-ketoglutarate to provide nitrogen and carbon sources for its growth.Compared to Halomonas sp.5021,Salinicola sp.4072 lacks anα-KGSA dehydrogenase gene in the T4LHyp gene cluster and can only catabolize T4LHyp into NH3 andα-ketoglutarate semialdehyde to provide a nitrogen source for its growth.Bioinformatic investigation showed that the 5021-like and 4072-like T4LHyp gene clusters are predominantly found in bacteria from Pseudomonadota,which are widely distributed in multiple marine habitats.Thus,Pseudomonadota bacteria are likely the dominant group to drive the recycling and mineralization of T4LHyp in the ocean.展开更多
基金support from the National Natural Science Foundation of China(U20A20112,42061160480,42377196,and 52479095)the NSFC/RGC Joint Research Scheme(42061160480 and N_HKUST620/20)+1 种基金the Research Grants Council of the Hong Kong SAR Government(16203720,T22-606/23-R,and JRFS25266S09)the Project of Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone(HZQB-KCZYB-2020083)。
文摘A glacier hazard chain can form a long-runout mass flow and generate a large flood,affecting downstream areas hundreds of kilometers away from the initiating hazard site.This study focuses on the Yarlung Zangbo Daxiagu.The objective is to address two key unresolved issues:the evolution of detached glacier materials into debris flows or debris floods and the amplification of the impact range and threats.A comprehensive framework is developed that considers the impacts of near-field and far-field hazards.Numerical modeling,remote sensing,and field investigations were integrated to understand the interactions,transformations,and amplifications of hazards in the glacier hazard chain.The results indicate that extensive,nearly saturated sediments on the glacier valley floor,when entrained,amplify the magnitude of the mass flow.The topography plays a crucial role.When the valley outlet is perpendicular to the river course,topographic obstacles cause immediate halting,resulting in the formation of high barrier dams.Conversely,when the glacier valley aligns nearly parallel to the river course,the mass flow can travel a much longer distance upon entering the river,causing an enlarged affected area.The barrier dams can breach rapidly,causing breaching floods that amplify the downstream impact from several kilometers to hundreds of kilometers.Our analysis reveals that the overall impacts remain spatially limited.Specifically,downstream areas along the Yarlung Zangbo-Brahmaputra River are unlikely to face greater threats from the upstream floods than local monsoon floods.Our findings provide the foundation for the management of glacier hazard chains.
基金jointly supported by the National Natural Science Foundation of China(Grant No.U2442207)the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2021427)+1 种基金the West Light Foundation(Grant No.xbzg-zdsys-202409)of the Chinese Academy of SciencesKey Talent Project in Gansu and Central Guidance Fund for Local Science and Technology Development Projects in Gansu(Grant No.24ZYQA031)。
文摘Water stress is expected to intensify due to escalating atmospheric and surface dryness under global warming.Despite extensive research indicate that intensified dryness exacerbates water constraints on ecosystems,the dynamics and underlying mechanisms of surface water stress(SWS)under climate change remain poorly understood.In this study,we use annual evaporative stress as the surface water stress index(WSI)and provide a comprehensive analysis of historical and projected global terrestrial SWS,covering its characteristic changes,driving factors,and impacts on vegetation.Our results show a significant declining trend in WSI during 1982–2014(-0.0033/decade,p<0.01),indicating the enhancement of SWS concurrent with a rapid expansion of water stress intensified areas at a rate of 1.85%/decade(p<0.01).Using the Budyko-Penman budget framework,we found that the intensification of SWS was primarily driven by an increase in vapor pressure deficit(VPD)and a decrease in precipitation.Furthermore,the intensification of SWS contributed to a decline in vegetation growth,with the extent of areas experiencing increased vegetation water deficit expanding rapidly at a rate of 1.38%per decade(p<0.01).In the future,SWS is projected to escalate,with the proportion of areas experiencing intensified SWS increasing from 6.3%to 24.3%by the end of the century under the SSP5–8.5.Our study provides a comprehensive analysis of the drivers of SWS under climate change and its impacts on ecosystems,offering valuable scientific insights for the effective management of water resources.
基金supported by the China Agriculture Research System (CARS11-HNCX)the Major Science and Technology Plan of Hainan Province (ZDKJ2021012)+3 种基金the Central Public-interest Scientific Institution Basal Research Fund for Chinese Academy of Tropical Agricultural Sciences (1630052022008)the National Key Research and Development Program of China (2018YFD1000501)the National Natural Science Foundation of China (31501378)the Hainan Yazhou Bay Seed Lab (B21HJ0303)。
文摘Drought stress impairs plant growth and other physiological functions. MeHDZ14, a homeodomainleucine zipper I transcription factor, is strongly induced by drought stress in various cassava cultivars.However, the role of MeHDZ14 in cassava growth regulation has remained unclear. Here we report that MeHDZ14 affected plant height, such that a dwarf phenotype and altered internode elongation were observed in transgenic cassava lines. MeHDZ14 was found to negatively regulate the biosynthesis of lignin. Its overexpression resulted in abaxially rolled leaves. The morphogenesis of leaf epidermal cells was inhibited by overexpression of MeHDZ14, with decreased auxin and gibberellin and increased cytokinin contents. MeHDZ14 was found to regulate many drought-responsive genes, including genes involved in cell wall synthesis and expansion. MeHDZ14 bound to the promoter of caffeic acid 3-Omethyltransferase 1(MeCOMT1), acting as a transcriptional repressor of genes involved in cell wall development. MeHDZ14 appears to act as a negative regulator of internode elongation and epidermal cell morphogenesis during cassava leaf development.
基金supported by the Hainan Provincial Natural Science Foundation of China (322RC798)the National Key Research and Development Program of China (2018YFD1000501)+1 种基金the Major Science and Technology Plan of Hainan Province (ZDKJ2021012)the China Agriculture Research System (CARS11-HNCX)。
文摘Chilling-induced accumulation of reactive oxygen species(ROS) is harmful to plants,which usually produce anthocyanins to scavenge ROS as protection from chilling stress.As a tropical crop,cassava is hypersensitive to chilling,but the biochemical basis of this hypersensitivity remains unclear.We previously generated Me MYB2-RNAi transgenic cassava with increased chilling tolerance.Here we report that Me MYB2-RNAi transgenic cassava accumulated less ROS but more cyanidin-3-O-glucoside than the wild type under early chilling stress.Under this stress,the anthocyanin biosynthesis pathway was more active in Me MYB2-RNAi lines than in the wild type,and several genes involved in the pathway,including Me TT8,were up-regulated by Me MYB2-RNAi in the transgenic cassava.Me MYB2 bound to the Me TT8 promoter and blocked its expression under both normal and chilling conditions,thereby inhibiting anthocyanin accumulation.Me TT8 was shown to bind to the promoter of Dihydroflavonol 4-reductase(Me DFR-2)and increased Me DFR-2 expression.Me MYB2 appears to act as an inhibitor of chilling-induced anthocyanin accumulation during the rapid response of cassava to chilling stress.
基金supported by the National Natural Science Foundation of China(Grants No.41991231,42041004,and 41888101)the China University Research Talents Recruitment Program(111 project,Grant No.B13045).
文摘Vegetation greening has long been acknowledged,but recent studies have pointed out that vegetation greening is possibly stalled or even reversed.However,detailed analyses about greening reversal or increased browning of vegetation remain scarce.In this study,we utilized the normalized difference vegetation index(NDVI)as an indicator of vegetation to investigate the trends of vegetation greening and browning(monotonic,interruption,and reversal)through the breaks for the additive season and trend(BFAST)method across China’s drylands from 1982 to 2022.It also reveals the impacts of ecological restoration programs(ERPs)and climate change on these vegetation trends.We find that the vegetation displays an obvious pattern of east-greening and west-browning in China’s drylands.Greening trends mainly exhibits monotonic greening(29.8%)and greening with setback(36.8%),whereas browning shows a greening to browning reversal(19.2%).The increase rate of greening to browning reversal is 0.0342/yr,which is apparently greater than that of greening with setback,0.0078/yr.This research highlights that,under the background of widespread vegetation greening,vegetation browning is pro-gressively increasing due to the effects of climate change.Furthermore,the ERPs have significantly increased vegetation coverage,with the increase rate in 2000-2022 being twice as much as that of 1982-1999 in reveg-etation regions.Vegetation browning in southwestern Qingzang Plateau is primarily driven by adverse climatic factors and anthropogenic disturbances,which offset the efforts of ERPs.
文摘Locoweed is a poisonous plant that severely harms the development of grass-land and animal husbandry throughout the world. Oxytropis and Astragalus are the Latin names for the poisonous plants commonly known as locoweed. The main toxic substance in these plants is swainsonine. It is a strong inhibitor of lysosomal α-mannosidase I and Golgi body α-mannosidase II, resulting in the accumulation of oligosaccharides and glycoproteins in lysosomes, interfering with the molecular and cellular recognition of glycans, and causing tissue-cell vacuolar degeneration. Livestock shows a series of clinical and pathological symptoms, mainly for the decline of reproductive performance. The effects in dams are abortion, weak fetus, and fetal malformations. The key step in maintaining pregnancy in dams is early endometrial decidualization, because reproductive hormones, decidual cell apoptosis, endoplasmic reticulum (ER) stress, and other immune factors are negatively affected by swainsonine. This article addresses the modifications that occur through glycan processing and glycosylation resulting in the change of post-translational modification of the protein and the activity of the glycoprotein, and then direct and indirect mechanisms of ER stress, apoptosis, reproductive hormones, immune factors, and cell cycle and other pathways. Our aim is to find new methods of prevention and treatment of swainsonine poisoning in grassland animals.
基金supported by the Natural Science Foundation of China (No. 51573004, No. 51773003, No. 51711540302)the Natural Science Foundation of Beijing City (No. Z16002)the Fundamental Research Funds for the Central Universities (No. 531107051056)
文摘As the development of smart electronics, self-powered sources have been attracting increasing attention.This review summarizes research progress of photovoltaic fibers and their integrated power sources with multi-stage energy conversion. Recent development of three dimensional photovoltaic fibers is glanced with special attention to structure design and materials of typical photovoltaic types（inorganic, organic,dye/quantum dot sensitized and perovskite solar cells）. The application of carbon materials in fiber energy is focused as it is a hot topic recently. The hybrid energy systems based on fiber solar cells and fiber supercapacitors, fiber batteries and fiber nanogenerators are summarized together with hybrid energy textiles. This review provides a macroscopic view of novel energy fibers and will attract research interest in flexible/wearable fiber electronics and energy textiles.
基金supported by the National Natural Science Foundation of China(No.51771072 and No.51901076)the Youth 1000 Talent Program of China,the Natural Science Foundation of Hunan Province(No.2019JJ50051)+1 种基金the Fundamental Research Funds for the Central Universitiesthe project support from State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body in Hunan University(No.71865007)。
文摘The hybrid battery integrating a typical Zn redox battery and a Zn-air battery is a promising green technology for energy storage,and the cathode integrating the redox reaction and electrocatalytic oxygen reduction is a key point for efficient electrochemical energy conversion.Herein,we report a scalable strategy to fabricate nanoporous Ag2 Al internetallic compound as a self-standing cathode for the hybrid Zn battery.The abundant surface oxygen species,the Ag-Al intermetallic interaction and the npAg_(2)Al@AgAlOx interface cooperatively contributed to the catalytic ORR activity.The electrode endows efficient catalytic oxygen reduction(a Tafel slope of 38.0 mV/dec and an onset potential of 0.998 V)and regulated redox activity as compared with Ag.The nanoporous channels allow efficient ion transport,interface charge exchange and gas molecular diffusion.Significantly,the assembled hybrid Zn-Ag_(2) Al/air battery delivers a high capacity of 3.23 mAh/cm^(2) as compared with recent reports.As far as we know,this is the first exploration for the electrochemical property of Ag2 Al,and it would inspire more exploration in developing multifunctional materials and robust hybrid batteries for practical applications.
基金Yingtan City Science and Technology Project(No.YKz20180033)
文摘Objective:To investigate the effects of sevoflurane inhalation general anesthesia on serum IL-6,brain injury protein S100βand coagulation function in elderly patients undergoing total hip arthroplasty.Method:From May 2017 to May 2019,84 patients,age 60-75 underwent total hip arthroplasty in our hospital.were randomly divided into two groups:group A(n=42)and group B(n=42).Group A was maintained with sevoflurane inhalation by general anesthesia and group B with propofol by intravenous anesthesia.The surgical related indexes and postoperative complications in the two groups were compared.The level of serum IL-6,S100β,Coagulation function index[platelet count(PLT),Fibrinogen(FIB),plasma D-dimer(D-D),activated partial enzyme activity time(APTT),prothrombin time(PT)],MMSE score and MoCA score were compared between two groups before and after operation.Results:There was no significant difference in anesthesia time,operation time,intraoperative bleeding and postoperative drainage(P>0.05).1h,1d and 7d after operation,the level of PLT,D-D and FIB in group A were significantly lower than that in group B(P<0.05),PT and APTT were significantly higher than that in group B(P<0.05).1h,1d and 7d after operation,the level of IL-6,S100βin group A were significantly lower than that in group B(P<0.05).1d after operation,the MMSE and MoCA scores in group B were significantly lower than those in group A(P<0.05).The incidence of lower extremity deep venous thrombosis(2.38%)and cognitive impairment(2.38%)in group A was lower than that in group B(14.29%,16.67%)(t1=3.896,P1=0.048;t2=4.974,P2=0.026).Conclusion:sevoflurane anesthesia can reduce the incidence of deep venous thrombosis and cognitive impairment of the lower extremity after operation in elderly patients with thr,stabilize the coagulation index of patients,and downregulate the expression of il-6 and S100β.
基金supported by the National Natural Science Foundation of China(No.62171325)the Experimental Technology Project of Wuhan University(No.WHU-2022-SYJS-11)the New Generation Computer Innovation and Entrepreneurship Center Project of Wuhan University。
文摘With the rise of artificial intelligence and the rapid development of industrial applications based on deep learning,the demand for innovative and practical talents is rapidly increased.The cultivation of talents in computer discipline has attracted a lot of attention from universities,research institutions,and Internet giants.Subject contests play a crucial role in cultivating top undergraduate talents.This paper proposes a cultivation model that takes the industry application of deep learning as the background,and guides students to learn,practice,and innovate incrementally from machine learning application to deep learning application by participating in subject contests.It aims to help undergraduates to master the cutting-edge technologies and applications,and ultimately cultivate top,innovative,and practical undergraduate talents in the computer field in the era of artificial intelligence.
基金Supported by 973 Program ( 2010CB126600 )863 Key Project ( 2007AA021307)+3 种基金National Natural Science Foundation ( 31000029 )Special Fund for Basic Research Operating Expenses of Central Nonprofit Research Institutions of Chinese Academy of Tropical Agriculture (ITBBKF1010,ITBBZD0951,ITTBB110103)Hainan Provincial Introduction Integrated Special Fund ( YJJC2011004 )Hainan Provincial Graduate Innovation Fund( Hyb2011-4)
文摘[ Objective ] This study aimed to identify a cellulase-producing strain selected from tropical rain forestry soils. [ Method ] Morphologic observation and sequence analysis of 18S rDNA were conducted. [Result] A cellulase-preducing strain with high activity was obtained, and morphology of the strain was highly similar to that of Trichoderma reesei. Results of sequence analysis show that the 18S rDNA sequence shares 99% homology with Hypocreajecorina. [ Conclusion] The isolated cellulase-producing strain belongs to Trichoderma reesei.
基金the Central Publicinterest Scientific Institution Basal Research Fund for Chinese Academy of Tropical Agricultural Sciences(1630052021026,1630052022008)the Major Science and Technology plan of Hainan Province(ZDKJ2021012)+1 种基金the National Key Research and Development Program of China(2018YFD1000500,2019YFD 1000500 and 2019YFD1001105)the Hainan Provincial Natural Science Foundation of China(320MS097).
文摘Cassava(Manihot esculenta Crantz)is a root crop significant in food security and various bio-industrial applications such as animal feed,modified starch,and biofuels.Drought and cold stress are two major factors limiting cassava production qualitatively and quantitatively,for which plants have evolved mechanisms to overcome the impact of these two stressors.In recent years,significant progress has been achieved in understanding the response mechanism of cassava plants to stress signals to tolerate the above stresses.In this review,core stress-signaling pathways,including transcription factor(TF)-related regulatory networks,plant hormone signaling,reactive oxygen species(ROS)scavenging,and non-coding RNA(ncRNA)and alternative splicing(AS)that modify gene expression levels in response to drought and/or cold stress in cassava,are summarized.Understanding these stress signaling and responses will increase our ability to improve the crops tolerance to multiple stresses for agricultural sustainability and food security for the growing world population.
基金supported by grants from the National Key R&D Program of China(2018YFD1000501)the National Natural Science Foundation of China-CG joint foundation(3181101517)the startup funds for the double first-class disciplines of crop science in Hainan University(RZ2100003362).
文摘Cassava is a highly resilient tropical crop that produces large,starchy storage roots and high biomass.However,how did cassava’s remarkable environmental adaptability and key economic traits evolve from its wild species remain unclear.In this study,we obtained near complete telomere-to-telomere genome assemblies and their haplotype forms for the cultivar AM560,the wild ancestors FLA4047 and W14,constructed a graphic pan-genome of 30 representatives with a size of 1.15 Gb,and built a clarified evolutionary tree of 486 accessions.A comparison of structural variations and single-nucleotide variations between the ancestors and cultivated cassavas reveals predominant expansions and contractions of numbers of genes and gene families,which are mainly driven by transposons.Significant selective sweeping occurred in 122 footprints of genomes and affects 1,519 domesticated genes.We identify selective mutations in MeCSK and MeFNR2 that could promote photoreactions associated with MeNADP-ME in C4 photosynthesis in modern cassava.Coevolution of retard floral primordia and initiation of storage roots may arise from MeCOL5 variants with altered bindings to MeFT1,MeFT2,and MeTFL2.Mutations in MeMATE1 and MeGTR occur in sweet cassava,and MeAHL19 has evolved to regulate the biosynthesis,transport,and endogenous remobilization of cyanogenic glucosides in cassava.These extensive genomic and gene resources provided here,along with the findings on the evolutionary mechanisms responsible for beneficial traits in modern cultivars,lay a strong foundation for future breeding improvements of cassava.
基金funded by the China Agriculture Research System of MOF and MARA(Grant No.CARS-03)supported by the 2115 Talent Development Program of China Agricultural University.
文摘To solve the problem of field waterlogging during wheat sowing in rice-wheat rotation areas,which causes sticky and wet soil,thus affecting the growth of wheat,this paper proposed a sloped ditching method based on laser alignment technology,and designed a combined ditching device with a front ditching shovel(FDS)and a rear ditching plow(RDP)to create sloped drainage furrows when sowing wheat.The key factors affecting the performance of RDP and value ranges were determined through theoretical analysis.Through discrete element method(DEM)simulation,the influence of different structural parameter combinations on slope stability was studied,and the optimal parameter combination was determined as the soil lifting angle of 50°,the minimum element angle of 35°,and the maximum element angle of 40°.The field test showed that the ditching device can effectively create sloped trapezoidal drainage furrows.The slope stability coefficient and slope accuracy coefficient were both greater than 85%,which meets the requirements of drainage.This paper provides a new ditching method and theoretical basis for the development of a sowing and ditching combined machine in rice stubble fields.
基金supported the National Natural Science Foundation of China(U2006205,32200021,32170127,32370136,42106142 and 42306166)the Natural Science Foundation of Shan-dong Province(ZR2021QD071)+2 种基金the State Key Laboratory of Micro-bial Technology Open Projects Fund(M2023-19)the SKLMT Fron-tiers and Challenges Project(SKLMTFCP-2023-06)the China Postdoctoral Science Foundation(BX20220193 and 2022M711921).
文摘Free trans-4-hydroxy-L-proline(T4LHyp),a non-proteinogenic amino acid,is mainly released from the degradation of collagen,hydroxyproline-rich glycoproteins,and some peptide antibiotics in nature.Although it has been known that some terrestrial bacteria utilize T4LHyp as carbon and nitrogen source via a T4LHyp gene cluster,which and how marine micro-organisms catabolize T4LHyp still remains unclear.Here,five T4LHyp-utilizing marine bacterial strains,Halomonas sp.5021,Salinicola sp.4072,Alteromonas sp.6022,Alteromonas sp.5112 and Alteromonas sp.30521,were isolated from hydrothermal vent sediment samples collected from the southwest Indian Ocean.While Halomonas sp.5021 can utilize T4LHyp as both a nitrogen and carbon source,the other four strains can utilize T4LHyp as only a nitrogen source.Then,the T4LHyp catabolic mechanisms of Halomonas sp.5021 and Salinicola sp.4072,as a representative of the four strains,were further investigated by genomic,transcriptional,and biochemical analyses.Halomonas sp.5021 adopts an intact T4LHyp gene cluster containing four enzymes to catabolize T4LHyp into NH3 andα-ketoglutarate to provide nitrogen and carbon sources for its growth.Compared to Halomonas sp.5021,Salinicola sp.4072 lacks anα-KGSA dehydrogenase gene in the T4LHyp gene cluster and can only catabolize T4LHyp into NH3 andα-ketoglutarate semialdehyde to provide a nitrogen source for its growth.Bioinformatic investigation showed that the 5021-like and 4072-like T4LHyp gene clusters are predominantly found in bacteria from Pseudomonadota,which are widely distributed in multiple marine habitats.Thus,Pseudomonadota bacteria are likely the dominant group to drive the recycling and mineralization of T4LHyp in the ocean.
