There are two formation routes of dietary N-nitrosamines:exogenous and endogenous formation.The formation of N-nitrosamines from either source requires precursors with a dialkylamine functional group and a nitrosating...There are two formation routes of dietary N-nitrosamines:exogenous and endogenous formation.The formation of N-nitrosamines from either source requires precursors with a dialkylamine functional group and a nitrosating agent.Precursors are supplied primarily by amine-rich foods and nitrosating agents are nitrite or its reaction products(N_(2)O_(3) and NO^(+)).Unprocessed fresh foods initially contain zero or only trace amounts of N-nitrosamines while significant amounts of N-nitrosamines can be generated during certain types of food processing.Cooking methods,pH,additives,and storage conditions can affect the formation of N-nitrosamines in foods.We analysed the formation mechanisms/pathways of the three most frequently detected N-nitrosamines in processed meats.Formation of endogenous N-nitrosamines is likely to be greater than that of exogenous N-nitrosamines.Nitrosating agents involved in the formation of endogenous N-nitrosamines are formed from nitrate in vegetables via the nitrate-nitrite-NO cycle.N-nitrosamines are produced in the human stomach and intestine but their formation mechanisms differ.We analysed the mechanism/pathway for the formation of N-nitrosotryptophan from tryptophan in the stomach.The formation of N-nitrosamines in the intestine includes both chemical and microbiological mechanisms.In addition to N-nitrosation,S-nitrosation also occurs in the human body.There is a competitive relationship between the two reactions,and S-nitrosation is more likely to occur in the healthy human body.This paper reviews the mechanisms and factors influencing the formation of exogenous and endogenous dietary N-nitrosamines,which illustrate the importance of microbial-mediated N-nitrosamine formation and the production of endogenous N-nitrosamines.展开更多
Horticultural crops suffer massive production losses due to abiotic stress,which is a key limiting factor worldwide.The ability of these crops to withstand such stress has been linked to melatonin,a biomolecule with s...Horticultural crops suffer massive production losses due to abiotic stress,which is a key limiting factor worldwide.The ability of these crops to withstand such stress has been linked to melatonin,a biomolecule with significant roles in both physiological and molecular defense responses.Melatonin is pivotal in enhancing the resilience of horticultural crops to abiotic stress,making it a critical component in their survival strategies.The application of exogenous melatonin improves abiotic stress tolerance by preserving membrane integrity,maintaining redox equilibrium,scavenging reactive oxygen species effectively,activating antioxidant defense mechanisms,and elevating gene expression related to stress responses.Furthermore,the integrated management of melatonin with other phytohormones demonstrates its potential relevance in addressing various stresses across a wide range of horticultural crops.Therefore,it is crucial to elucidate the physiological and molecular processes involving melatonin in abiotic stress in these crops.Here,we discuss current studies on the use of melatonin in horticultural crops in response to abiotic stresses,and explores future research directions and potential applications to enhance the productivity and abiotic stress tolerance of horticultural crops.展开更多
Rice(Oryza sativa L.)root characteristics are closely associated with nitrogen(N)uptake,root growth and development are greatly influenced by ethylene.In this study,a hydroponic experiment was conducted using four ric...Rice(Oryza sativa L.)root characteristics are closely associated with nitrogen(N)uptake,root growth and development are greatly influenced by ethylene.In this study,a hydroponic experiment was conducted using four rice genotypes[Shanyou 63(SY63)and Zhonghua 11(ZH11)with well–developed aerenchyma;Yangdao 6(YD6)and mutant rcn1 from ZH11 with less–developed aerenchyma]to investigate the effects of exogenous ethephon(Eth)on root characteristics,N uptake,dry matter distribution,and clarify the underlying relationship.Compared with YD6 and rcn1,SY63 and ZH11 had higher N accumulation,higher root aerenchyma area to cortex area ratio(ACR),higher NH_(4)^(+)uptake via the apoplasmic pathway and root-to-shoot NH_(4)^(+)translocation under no ethephon application(NEth)and Eth treatment,and elevated expression of the three genes(OsAMT1;2,OsAMT2;2,and OsAMT4;1)for ammonium transporters under Eth treatment.Eth treatment increased shoot N and dry matter accumulation,decreased the total root length and root diameter,and increased ACR and the expression of OsAMT genes in four genotypes.In summary,Eth could increase N accumulation via modifying root characteristics in rice,particularly by enlarging root aerenchyma and thinning the roots.The findings provide implications for development of elite rice varieties and green rice production with higher N efficiency.展开更多
This article presents an adaptive optimal control method for a semi-active suspension system.The model of the suspension system is built,in which the components of uncertain parameters and exogenous disturbance are de...This article presents an adaptive optimal control method for a semi-active suspension system.The model of the suspension system is built,in which the components of uncertain parameters and exogenous disturbance are described.The adaptive optimal control law consists of the sum of the optimal control component and the adaptive control component.First,the optimal control law is designed for the model of the suspension system after ignoring the components of uncertain parameters and exogenous disturbance caused by the road surface.The optimal control law expresses the desired dynamic characteristics of the suspension system.Next,the adaptive component is designed with the purpose of compensating for the effects caused by uncertain parameters and exogenous disturbance caused by the road surface;the adaptive component has adaptive parameter rules to estimate uncertain parameters and exogenous disturbance.When exogenous disturbances are eliminated,the system responds with an optimal controller designed.By separating theoretically the dynamic of a semi-active suspension system,this solution allows the design of two separate controllers easily and has reduced the computational burden and the use of too many tools,thus allowing for more convenient hardware implementation.The simulation results also show the effectiveness of damping oscillations of the proposed solution in this article.展开更多
Exogenous proline is an effective agent for increasing plant tolerance to abiotic stress in plants. In this study, we evaluated its effect on seedlings of Siete Caldos chili pepper (Capsicum frutescens), a semi-domest...Exogenous proline is an effective agent for increasing plant tolerance to abiotic stress in plants. In this study, we evaluated its effect on seedlings of Siete Caldos chili pepper (Capsicum frutescens), a semi-domesticated variety. The Capsicum genus is known for its sensitivity to water stress. We pretreated the seedlings’ roots by immersing them in proline solutions (0, 2.5, 5, 7.5, and 10 mM) for 48 h. Then, we exposed them to water stress using a Hoagland nutrient solution supplemented with 10% polyethylene glycol (PEG-8000) for nine days. We analyzed key physiological and biochemical parameters, including relative water content, cell membrane stability index, electrolyte leakage, chlorophyll, and proline content. The results indicated that proline concentrations of 2.5 and 5 mM significantly increased tolerance to water stress, with 100% survival. These seedlings maintained greater hydration and cell membrane stability compared to non-pretreated seedlings. In contrast, at the highest concentrations (7.5 and 10 mM Pro), survival was 63.63% and 54.54%, respectively. This study demonstrated that exogenous proline enhances water stress tolerance in Capsicum frutescens seedlings by mitigating the negative impact on physiological and biochemical processes vital for survival. This theoretical foundation can be applied to improve chili seedling performance in controlled production environments.展开更多
CRISPR-based tran-scription regulators(CRISPR-TRs)have revolutionized the field of synthetic biol-ogy by enabling tar-geted activation or repression of any de-sired gene.However,the majority of exist-ing inducible CRI...CRISPR-based tran-scription regulators(CRISPR-TRs)have revolutionized the field of synthetic biol-ogy by enabling tar-geted activation or repression of any de-sired gene.However,the majority of exist-ing inducible CRISPR-TRs are limited by their dependence on specific sequences,which restricts their flex-ibility and controllability in genetic engineering applications.In this study,we proposed a novel strategy to construct sequence-independent inducible CRISPR-TRs,which is achieved by the design of stem loop 2 in the single guide RNA(sgRNA).Under this strategy,by utiliz-ing toehold-mediated strand displacement(TMSD)reactions between small endogenous molecules(miR-20a and TK1 mRNA)and bridge RNA(bRNA)to link bRNA with sgRNA,we achieved synergistic transcriptional activation of VP64 and p65-HSF1 in response to en-dogenous molecules.To enable response to exogenous molecules,we added response se-quences and bRNA sequences to the 5'end of sgRNA to block sgRNA activity,and achieved activation of sgRNA by shearing the response sequence,called sequential unlimited interlock-ing(SUI).Compared with conventional sequence-restricted interlocking(spacer-blocking hairpin(SBH)),the transcriptional activation ratio between response and non-response to the Cas6A protein using our approach was increased by 2.28-fold.Our work presents a modular and versatile framework for endogenous and exogenous molecule-responsive CRISPR-TRs in mammalian cells,without limitations imposed by sequence dependence.展开更多
Alzheimer’s disease(AD)is a neurodegenerative disease causing the most frequent form of dementia in old age.AD etiology is still uncertain and deposition of abnormal proteins in the brain along with chronic neuroinfl...Alzheimer’s disease(AD)is a neurodegenerative disease causing the most frequent form of dementia in old age.AD etiology is still uncertain and deposition of abnormal proteins in the brain along with chronic neuroinflammation have been suggested as pathogenic mechanisms of neuronal death.Infections by exogenous neurotropic virus,endogenous retrovirus reactivation,infections by other microbes,and air pollutants may either induce neurodegeneration or activate brain inflammation.Up to 8%of the human genome has a retroviral origin.These ancient retroviruses,also called human endogenous retroviruses,are associated with a clinical history of several neurodegenerative diseases.Under persistent stress,such as chronic infections and inflammation,neurons,and microglia cells may enter a state of division inactivation called cell senescence.Senescent cells are resistant to apoptosis and can release pro-inflammatory molecules promoting the functional decline of tissues and organs and also activate silent viruses.Infections andmutations induced by pollutants can lead to the expression of different endogenous retroviruses,which may contribute to several different diseases,including AD-associated neurodegeneration.Here I discuss that infection by exogenous pathogen,activation of endogenous retrovirus or retrotransposons and pollutants might induce neuronal senescence and cause persistent brain neurodegeneration.Therefore,cell senescence appears to be an emerging mechanism that might contribute to AD neurodegeneration.Finally,treatment of AD patients with senolytic drugs,e.g.,compounds able to kill senescent cells,might show a positive effect on AD progression.展开更多
The vaginal microbiome plays a pivotal role in maintaining vaginal health and protecting the host from various diseases.There is a broad agreement within the scientific community that the vaginal microbiome exhibits s...The vaginal microbiome plays a pivotal role in maintaining vaginal health and protecting the host from various diseases.There is a broad agreement within the scientific community that the vaginal microbiome exhibits stable bacterial diversity,influenced by age and gonadal hormone levels,and is classified into distinct Community-State Types.A healthy vaginal microbiome is typically characterized by a predominance of Lactobacillus spp.,which acidifies the vaginal environment and is essential in defending against invading microbial pathogens.This review examines the evolution of the vaginal microbiome’s composition throughout a woman’s life.It also explores how exogenous factors influence the homeostasis of this microbiome,leading to either a state of eubiosis or dysbiosis.The main factors supporting eubiosis of the vaginal microbiome include diet,probiotic intake,certain personal hygiene practices,and hormonal contraceptives,while the major contributors to dysbiosis are psychosocial stress,tobacco smoking,and sexual activity.This state of dysbiosis is strongly associated with a range of adverse vaginal health outcomes,including preterm birth,bacterial vaginosis,pelvic inflammatory disease,and a higher risk of sexually transmitted infections.展开更多
BACKGROUND Exogenous insulin may trigger immune-mediated complications,particularly among East Asian populations.Double diabetes,characterized by overlapping features of type 1 diabetes(T1D)and type 2 diabetes(T2D),ma...BACKGROUND Exogenous insulin may trigger immune-mediated complications,particularly among East Asian populations.Double diabetes,characterized by overlapping features of type 1 diabetes(T1D)and type 2 diabetes(T2D),may arise from insulin-induced autoimmunity.This study aimed to explore the association between high-risk human leukocyte antigen(HLA)class Ⅱ genotypes and susceptibility to double diabetes in patients initially diagnosed with T2D.AIM To investigate clinical and immunogenic features of patients who develop double diabetes following exogenous insulin therapy.METHODS We retrospectively analyzed five cases from Peking Union Medical College Hospital and 18 cases identified from published literature.Patients were categorized into two groups:The T2D→T1D group,characterized by autoimmune progression,and the stable T2D(T2D→T2D).Clinical characteristics and HLA class Ⅱ genotypes were compared descriptively between the two groups.RESULTS A total of 23 patients were included in the analysis.Of these,10 progressed from theT2D→T1D with autoimmune features,while 13 remained in the stable T2D→T2D group.There was no statistically significant difference in age at diagnosis between the two groups(57.10±16.11 years vs 60.31±17.41 years).In the T2D→T1D group,70%of patients carried the HLA-DRB104:05 allele and 40%carried DRB109:01,both of which are commonly associated with a high risk of T1D.In contrast,the T2D→T2D group showed greater genetic heterogeneity,with a broader distribution of HLA-DRB1 alleles,including DRB103:02(n=4),DRB109:01(n=4),and several lower frequency alleles such as DRB1*04:05,*08:03,*03:01,*04:06,*14:01,*04:01,*12:02,*15:02 and*02:01.CONCLUSION These findings suggest that patients in the T2D→T1D group exhibit a stronger autoimmune genetic predisposition,characterized by an enrichment of high-risk HLA class II alleles.In contrast,individuals with stable T2D demonstrate greater HLA diversity and lack definitive autoimmune-associated markers.展开更多
This study explores the broad-spectrum application of OsRALF26,a small secreted peptide belonging to the rapid alkalinization factor(RALF)family in rice.We found that the rice genome carries numerous lineage-specific ...This study explores the broad-spectrum application of OsRALF26,a small secreted peptide belonging to the rapid alkalinization factor(RALF)family in rice.We found that the rice genome carries numerous lineage-specific OsRALFs,suggesting that this evolutionary expansion could be the result of an arms race with pathogens.Among them,we focused on the Oryza-specific Os RALF26 and its closest homolog,OsRALF27,analyzing their effects across a range of plant species from monocots to dicots.The exogenous application of OsRALF26 significantly reduced bacterial populations in rice challenged with Xanthomonas oryzae pv.oryzae(Xoo)and in Arabidopsis and tomato challenged with Pseudomonas syringae pv.tomato DC3000(Pst DC3000),whereas Os RALF27 did not enhance resistance.展开更多
In the field of railway traction drive systems,voltage sensor intermittent faults can significantly impact the reliability and safety of the entire system.This paper proposes an online diagnosis method for detecting s...In the field of railway traction drive systems,voltage sensor intermittent faults can significantly impact the reliability and safety of the entire system.This paper proposes an online diagnosis method for detecting such faults using an Artificial Intelligence(AI)predictor based on a Nonlinear Autoregressive with eXogenous inputs(NARX)data structure.The model is trained efficiently using the Extreme Learning Machine(ELM)algorithm.The NARX model captures the dynamic characteristics of the voltage sensor data,enabling the AI predictor to learn complex nonlinear relationships.The ELM training method ensures rapid convergence and high accuracy.Through extensive experimental validation,the proposed method demonstrates high sensitivity to voltage sensor intermittent faults and robust performance under varying operating conditions.This approach offers a promising solution for enhancing the diagnostic capabilities of railway traction systems,ensuring timely fault detection and improving overall system reliability.展开更多
[Objective] The research aimed to map QTL for the sensitivity of the traits related outcrosssing of Japonica rice to exogenous GA3 and provide theoretical basis for breeding and improving the high-sensitivity sterile ...[Objective] The research aimed to map QTL for the sensitivity of the traits related outcrosssing of Japonica rice to exogenous GA3 and provide theoretical basis for breeding and improving the high-sensitivity sterile line.[Method] Taking Japonica rice Xiushui 79 and C bao and their recombinant inbred line population 260 lines as test materials,the sensitivity of 4 traits related outcrossing to Exogenous GA3 and their QTL mapping were studied by using composite interval mapping..[Result]Three QTLs,which cont...展开更多
Objective The purpose of this experiment was to investigate the effects of exogenous hormone factors on subculture multiplication and root induction of tis-suecultured seedlings in mulberry. [Method] The aseptic seedl...Objective The purpose of this experiment was to investigate the effects of exogenous hormone factors on subculture multiplication and root induction of tis-suecultured seedlings in mulberry. [Method] The aseptic seedlings of Guisangyou 12 were used as the materials and the comparative experiment on subculture multi-plication and root induction used different kinds,concentrations and combinations of exogenous hormones. [Result] The hormone combination of 0.1 mg/L IBA＋1.5 mg/L 6-BA＋0.03 mg/L TDZ showed the best effects to bud multiplication, and the multiple of bud multiplication was 5.28. The effects of NAA was better than IBA and IAA on root induction. The hormone combination of 2.0 mg/L NAA＋1.0 mg/L PP333 was most suitable to the root induction, in which the rooting rate arrived to 100%, the root number was 7.01 and the root length was 1.38 cm on average. [Conclusion] The results wil provide some technical reference for large-scale propagation of mul-berry seedlings in vitro.展开更多
The content of total sugar, sucrose, fructose and protein in the leaves of3-yr.-old Betula platyphylla was measured after the treatment by three exogenous sugar solutions(sucrose, fructose, glucose) and three high con...The content of total sugar, sucrose, fructose and protein in the leaves of3-yr.-old Betula platyphylla was measured after the treatment by three exogenous sugar solutions(sucrose, fructose, glucose) and three high concentrations of CO_2 (700, 1 400, 2 100 μL/L·L^(-1))for about a month in 1998. The results showed that spraying three exogenous sugar solutionsincreased markedly the content of sugar and protein of leaves under 700 μL·L^(-1) and 1 400μL·L^(-1) CO_2 The effect of spraying exogenous sucrose solution was the best among the threeexogenous sugars. The treatment of spraying exogenous sugar solution and 2 100 μL·L^(-1) CO_2constrained the accumulation of total sugar and protein of leaves. There was no difference inprotein content of leaves when spraying glucose and fructose solutions under 700 μL·L^(-1) and 1400 μL·L^(-1) CO_2. The treatment of 2 100 μL·L^(-1) CO_2 concentration significantly increasedthe contents of total sugar, sucrose, fructose, and protein of leaves compared with that of the 700μL·L^(-1) and 1 400 μL·L^(-1) CO_2 except the plants spraying fructose solution. There waspositive correlation between the content of sugar of leaves and CO_2 concentration when sprayingsame exogenous sugar solution.展开更多
[Objective] This study was conducted to reveal the effect of exogenous calcium （Ca） in mitigating the damage caused by NaCI stress to watermelon seedlings. [Method] To the liquid medium containing 100 mmol/L NaCI, C...[Objective] This study was conducted to reveal the effect of exogenous calcium （Ca） in mitigating the damage caused by NaCI stress to watermelon seedlings. [Method] To the liquid medium containing 100 mmol/L NaCI, CaSO4 was added to the final concentrations of 4, 6, 10 and 14 mmol/L. The morphological and physiological indices including plant height, stem diameter, number of leaves per plant, maximum leaf length, maximum leaf width, seedling fresh weight and dry weight, malondialdehyde （MDA） content, relative permeability of plasma membrane, ascorbic acid （AsA） content, free proline content, soluble sugar content and soluble protein content in leaves of the seedlings treated with above media for 10 d were measured. [Result] NaCI stress significantly inhibited the growth of watermelon seedlings. The membrane permeability and MDA content in leaves were significantly increased under NaCI stress, and the contents of proline, soluble sugar, soluble protein and AsA were increased to different extents. Exogenous CaSO4 influenced the morphological and physiological indices of seedlings under NaCI stress in a manner. Treated with 6 mmol/L CaSO4, the growth of seedlings under salinity was significantly improved; membrane permeability and MDA content were drastically reduced, the contents of proline, soluble sugar, soluble pro- tein and AsA in leaves were significantly increased. [Conclusion] Exogenous CaSO＋ alleviates lipid peroxidation and inhibition of seedling growth under NaCI stress by improving the abilities of antioxidation and osmotic adjustment, and 6 mmol/L CaSO4 showed the best effect.展开更多
[Objective] The paper was to study the effects of exogenous GA3 on seed germination and seedling growth of Salicornia europaea L.under salt stress.[Method] With the combination of different concentrations of NaCl（50,...[Objective] The paper was to study the effects of exogenous GA3 on seed germination and seedling growth of Salicornia europaea L.under salt stress.[Method] With the combination of different concentrations of NaCl（50,100,150,200,250,300,350,400 mmol/L）with 10 μmol /L GA3 treatments,the effects of exogenous GA3 on seed germination and seedling growth of S.europaea under salt stress were studied.[Result] Exogenous GA3 promoted the seed germination rate,germination capacity,germination index and seed vigor index of S.europaea under salt stress.Under the treatment of exogenous GA3,the root system vigor,the lengths of roots and stems and the salt-tolerance of S.europaea were higher than that of single salt stress treatment.[Conclusion] Within a certain concentration range,exogenous GA3 could alleviate the inhibition effects of salt stress on seed germination and seedling growth of S.europaea.展开更多
The dynamic effect is a very important issue widely debated by scholars when studying the genetic and disaster-causing mechanisms of earthquake-triggered landslides.First,the dynamic effect mechanism and phenomena of ...The dynamic effect is a very important issue widely debated by scholars when studying the genetic and disaster-causing mechanisms of earthquake-triggered landslides.First,the dynamic effect mechanism and phenomena of earthquake-triggered landslides were summarized in this paper.Then,the primary types of dynamic effects were further used to interpret the Mogangling landslide in Moxi Town of Luding County,China.A field investigation,remote sensing,numerical calculation and theoretical analysis were carried out to illustrate the failure mechanism of slope rock masses affected by earthquakes.The interaction between seismic waves and slope rock masses and the induced dynamic effect of slope rock masses were primarily accounted for in the analysis.The slope topography,rock mass weathering and unloading characteristics,river erosion,regional seismogenic structure,and rock mass structure characteristics were also discussed.The results showed that the formation of the Mogangling landslide was mainly related to the high amplification effect of seismic acceleration and back slope effects,interface dynamic stress effects,and double-sided slope effects of seismic waves caused by the catastrophic Ms 7.75 Moxi Earthquake in 1786.The principles for the site and route selection of large-scale infrastructure in the planning stage and the scientific prevention of seismic geological disasters were proposed on the basis of the dynamic effect of earthquake-induced landslides.展开更多
The mechanisms of sex determination and the influence of exogenous factors on sex differentiation in crustacean were reviewed in the paper.Most of crustecea have not obviously sex chromosome.Androgenic gland was repor...The mechanisms of sex determination and the influence of exogenous factors on sex differentiation in crustacean were reviewed in the paper.Most of crustecea have not obviously sex chromosome.Androgenic gland was reported as the most important sex differentiation factors,implanting or cuting AG can change the sexal characterization of larval in crustacean.Although sex differentiation of crustacean is determined by gene,it is affected by exogenous factors such as parasite,photoperiod,temperature or hormone.Most cultured species have different body weight and length between male and female,this can be used in aquaculture to produce all male or female crusteceans to improve the production.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22376114 and 22076091)the State Key Joint Laboratory of Environment Simulation and Pollution Control,China(No.21L01ESPC)the Youth Science and Technology Innovation Program of Xiamen Ocean and Fisheries Development Special Funds(No.23YYST062QCB29)。
文摘There are two formation routes of dietary N-nitrosamines:exogenous and endogenous formation.The formation of N-nitrosamines from either source requires precursors with a dialkylamine functional group and a nitrosating agent.Precursors are supplied primarily by amine-rich foods and nitrosating agents are nitrite or its reaction products(N_(2)O_(3) and NO^(+)).Unprocessed fresh foods initially contain zero or only trace amounts of N-nitrosamines while significant amounts of N-nitrosamines can be generated during certain types of food processing.Cooking methods,pH,additives,and storage conditions can affect the formation of N-nitrosamines in foods.We analysed the formation mechanisms/pathways of the three most frequently detected N-nitrosamines in processed meats.Formation of endogenous N-nitrosamines is likely to be greater than that of exogenous N-nitrosamines.Nitrosating agents involved in the formation of endogenous N-nitrosamines are formed from nitrate in vegetables via the nitrate-nitrite-NO cycle.N-nitrosamines are produced in the human stomach and intestine but their formation mechanisms differ.We analysed the mechanism/pathway for the formation of N-nitrosotryptophan from tryptophan in the stomach.The formation of N-nitrosamines in the intestine includes both chemical and microbiological mechanisms.In addition to N-nitrosation,S-nitrosation also occurs in the human body.There is a competitive relationship between the two reactions,and S-nitrosation is more likely to occur in the healthy human body.This paper reviews the mechanisms and factors influencing the formation of exogenous and endogenous dietary N-nitrosamines,which illustrate the importance of microbial-mediated N-nitrosamine formation and the production of endogenous N-nitrosamines.
基金supported by the National Natural Science Foundation of China(Grant No.32060672)Natural Science Foundation of Ningxia Province(Grant No.2023AAC03070)Central guidance for local scientific and technological development funds(Grant No.2022ZY0106)。
文摘Horticultural crops suffer massive production losses due to abiotic stress,which is a key limiting factor worldwide.The ability of these crops to withstand such stress has been linked to melatonin,a biomolecule with significant roles in both physiological and molecular defense responses.Melatonin is pivotal in enhancing the resilience of horticultural crops to abiotic stress,making it a critical component in their survival strategies.The application of exogenous melatonin improves abiotic stress tolerance by preserving membrane integrity,maintaining redox equilibrium,scavenging reactive oxygen species effectively,activating antioxidant defense mechanisms,and elevating gene expression related to stress responses.Furthermore,the integrated management of melatonin with other phytohormones demonstrates its potential relevance in addressing various stresses across a wide range of horticultural crops.Therefore,it is crucial to elucidate the physiological and molecular processes involving melatonin in abiotic stress in these crops.Here,we discuss current studies on the use of melatonin in horticultural crops in response to abiotic stresses,and explores future research directions and potential applications to enhance the productivity and abiotic stress tolerance of horticultural crops.
基金supported by the National Natural Science Foundation of China(31671598).
文摘Rice(Oryza sativa L.)root characteristics are closely associated with nitrogen(N)uptake,root growth and development are greatly influenced by ethylene.In this study,a hydroponic experiment was conducted using four rice genotypes[Shanyou 63(SY63)and Zhonghua 11(ZH11)with well–developed aerenchyma;Yangdao 6(YD6)and mutant rcn1 from ZH11 with less–developed aerenchyma]to investigate the effects of exogenous ethephon(Eth)on root characteristics,N uptake,dry matter distribution,and clarify the underlying relationship.Compared with YD6 and rcn1,SY63 and ZH11 had higher N accumulation,higher root aerenchyma area to cortex area ratio(ACR),higher NH_(4)^(+)uptake via the apoplasmic pathway and root-to-shoot NH_(4)^(+)translocation under no ethephon application(NEth)and Eth treatment,and elevated expression of the three genes(OsAMT1;2,OsAMT2;2,and OsAMT4;1)for ammonium transporters under Eth treatment.Eth treatment increased shoot N and dry matter accumulation,decreased the total root length and root diameter,and increased ACR and the expression of OsAMT genes in four genotypes.In summary,Eth could increase N accumulation via modifying root characteristics in rice,particularly by enlarging root aerenchyma and thinning the roots.The findings provide implications for development of elite rice varieties and green rice production with higher N efficiency.
基金supported in part by the Thai Nguyen University of Technology,Vietnam.
文摘This article presents an adaptive optimal control method for a semi-active suspension system.The model of the suspension system is built,in which the components of uncertain parameters and exogenous disturbance are described.The adaptive optimal control law consists of the sum of the optimal control component and the adaptive control component.First,the optimal control law is designed for the model of the suspension system after ignoring the components of uncertain parameters and exogenous disturbance caused by the road surface.The optimal control law expresses the desired dynamic characteristics of the suspension system.Next,the adaptive component is designed with the purpose of compensating for the effects caused by uncertain parameters and exogenous disturbance caused by the road surface;the adaptive component has adaptive parameter rules to estimate uncertain parameters and exogenous disturbance.When exogenous disturbances are eliminated,the system responds with an optimal controller designed.By separating theoretically the dynamic of a semi-active suspension system,this solution allows the design of two separate controllers easily and has reduced the computational burden and the use of too many tools,thus allowing for more convenient hardware implementation.The simulation results also show the effectiveness of damping oscillations of the proposed solution in this article.
文摘Exogenous proline is an effective agent for increasing plant tolerance to abiotic stress in plants. In this study, we evaluated its effect on seedlings of Siete Caldos chili pepper (Capsicum frutescens), a semi-domesticated variety. The Capsicum genus is known for its sensitivity to water stress. We pretreated the seedlings’ roots by immersing them in proline solutions (0, 2.5, 5, 7.5, and 10 mM) for 48 h. Then, we exposed them to water stress using a Hoagland nutrient solution supplemented with 10% polyethylene glycol (PEG-8000) for nine days. We analyzed key physiological and biochemical parameters, including relative water content, cell membrane stability index, electrolyte leakage, chlorophyll, and proline content. The results indicated that proline concentrations of 2.5 and 5 mM significantly increased tolerance to water stress, with 100% survival. These seedlings maintained greater hydration and cell membrane stability compared to non-pretreated seedlings. In contrast, at the highest concentrations (7.5 and 10 mM Pro), survival was 63.63% and 54.54%, respectively. This study demonstrated that exogenous proline enhances water stress tolerance in Capsicum frutescens seedlings by mitigating the negative impact on physiological and biochemical processes vital for survival. This theoretical foundation can be applied to improve chili seedling performance in controlled production environments.
基金supported by the National Natural Science Foundation of China(No.22073090,No.21991132,No.52021002)the National Key R&D Program of China(No.2020YFA0710700)the Funds of Youth Innovation Promotion Association,and the Fundamental Research Funds for the Central Universities(WK3450000009).
文摘CRISPR-based tran-scription regulators(CRISPR-TRs)have revolutionized the field of synthetic biol-ogy by enabling tar-geted activation or repression of any de-sired gene.However,the majority of exist-ing inducible CRISPR-TRs are limited by their dependence on specific sequences,which restricts their flex-ibility and controllability in genetic engineering applications.In this study,we proposed a novel strategy to construct sequence-independent inducible CRISPR-TRs,which is achieved by the design of stem loop 2 in the single guide RNA(sgRNA).Under this strategy,by utiliz-ing toehold-mediated strand displacement(TMSD)reactions between small endogenous molecules(miR-20a and TK1 mRNA)and bridge RNA(bRNA)to link bRNA with sgRNA,we achieved synergistic transcriptional activation of VP64 and p65-HSF1 in response to en-dogenous molecules.To enable response to exogenous molecules,we added response se-quences and bRNA sequences to the 5'end of sgRNA to block sgRNA activity,and achieved activation of sgRNA by shearing the response sequence,called sequential unlimited interlock-ing(SUI).Compared with conventional sequence-restricted interlocking(spacer-blocking hairpin(SBH)),the transcriptional activation ratio between response and non-response to the Cas6A protein using our approach was increased by 2.28-fold.Our work presents a modular and versatile framework for endogenous and exogenous molecule-responsive CRISPR-TRs in mammalian cells,without limitations imposed by sequence dependence.
文摘Alzheimer’s disease(AD)is a neurodegenerative disease causing the most frequent form of dementia in old age.AD etiology is still uncertain and deposition of abnormal proteins in the brain along with chronic neuroinflammation have been suggested as pathogenic mechanisms of neuronal death.Infections by exogenous neurotropic virus,endogenous retrovirus reactivation,infections by other microbes,and air pollutants may either induce neurodegeneration or activate brain inflammation.Up to 8%of the human genome has a retroviral origin.These ancient retroviruses,also called human endogenous retroviruses,are associated with a clinical history of several neurodegenerative diseases.Under persistent stress,such as chronic infections and inflammation,neurons,and microglia cells may enter a state of division inactivation called cell senescence.Senescent cells are resistant to apoptosis and can release pro-inflammatory molecules promoting the functional decline of tissues and organs and also activate silent viruses.Infections andmutations induced by pollutants can lead to the expression of different endogenous retroviruses,which may contribute to several different diseases,including AD-associated neurodegeneration.Here I discuss that infection by exogenous pathogen,activation of endogenous retrovirus or retrotransposons and pollutants might induce neuronal senescence and cause persistent brain neurodegeneration.Therefore,cell senescence appears to be an emerging mechanism that might contribute to AD neurodegeneration.Finally,treatment of AD patients with senolytic drugs,e.g.,compounds able to kill senescent cells,might show a positive effect on AD progression.
文摘The vaginal microbiome plays a pivotal role in maintaining vaginal health and protecting the host from various diseases.There is a broad agreement within the scientific community that the vaginal microbiome exhibits stable bacterial diversity,influenced by age and gonadal hormone levels,and is classified into distinct Community-State Types.A healthy vaginal microbiome is typically characterized by a predominance of Lactobacillus spp.,which acidifies the vaginal environment and is essential in defending against invading microbial pathogens.This review examines the evolution of the vaginal microbiome’s composition throughout a woman’s life.It also explores how exogenous factors influence the homeostasis of this microbiome,leading to either a state of eubiosis or dysbiosis.The main factors supporting eubiosis of the vaginal microbiome include diet,probiotic intake,certain personal hygiene practices,and hormonal contraceptives,while the major contributors to dysbiosis are psychosocial stress,tobacco smoking,and sexual activity.This state of dysbiosis is strongly associated with a range of adverse vaginal health outcomes,including preterm birth,bacterial vaginosis,pelvic inflammatory disease,and a higher risk of sexually transmitted infections.
基金Supported by CAMS Innovation Fund for Medical Sciences,No.2021-I2M-1-002Healthcare Quality and Safety Incubation Programme of the Peking Union Medical Foundation,No.XHFY 2406the National High-Level Hospital Clinical Research Funding,No.2022-PUMCH-B-015.
文摘BACKGROUND Exogenous insulin may trigger immune-mediated complications,particularly among East Asian populations.Double diabetes,characterized by overlapping features of type 1 diabetes(T1D)and type 2 diabetes(T2D),may arise from insulin-induced autoimmunity.This study aimed to explore the association between high-risk human leukocyte antigen(HLA)class Ⅱ genotypes and susceptibility to double diabetes in patients initially diagnosed with T2D.AIM To investigate clinical and immunogenic features of patients who develop double diabetes following exogenous insulin therapy.METHODS We retrospectively analyzed five cases from Peking Union Medical College Hospital and 18 cases identified from published literature.Patients were categorized into two groups:The T2D→T1D group,characterized by autoimmune progression,and the stable T2D(T2D→T2D).Clinical characteristics and HLA class Ⅱ genotypes were compared descriptively between the two groups.RESULTS A total of 23 patients were included in the analysis.Of these,10 progressed from theT2D→T1D with autoimmune features,while 13 remained in the stable T2D→T2D group.There was no statistically significant difference in age at diagnosis between the two groups(57.10±16.11 years vs 60.31±17.41 years).In the T2D→T1D group,70%of patients carried the HLA-DRB104:05 allele and 40%carried DRB109:01,both of which are commonly associated with a high risk of T1D.In contrast,the T2D→T2D group showed greater genetic heterogeneity,with a broader distribution of HLA-DRB1 alleles,including DRB103:02(n=4),DRB109:01(n=4),and several lower frequency alleles such as DRB1*04:05,*08:03,*03:01,*04:06,*14:01,*04:01,*12:02,*15:02 and*02:01.CONCLUSION These findings suggest that patients in the T2D→T1D group exhibit a stronger autoimmune genetic predisposition,characterized by an enrichment of high-risk HLA class II alleles.In contrast,individuals with stable T2D demonstrate greater HLA diversity and lack definitive autoimmune-associated markers.
基金supported by the National Research Foundation of Korea grant funded by the Korea government(Grant Nos.NRF-2020R1A2C1007778 and RS-2024-00454908)。
文摘This study explores the broad-spectrum application of OsRALF26,a small secreted peptide belonging to the rapid alkalinization factor(RALF)family in rice.We found that the rice genome carries numerous lineage-specific OsRALFs,suggesting that this evolutionary expansion could be the result of an arms race with pathogens.Among them,we focused on the Oryza-specific Os RALF26 and its closest homolog,OsRALF27,analyzing their effects across a range of plant species from monocots to dicots.The exogenous application of OsRALF26 significantly reduced bacterial populations in rice challenged with Xanthomonas oryzae pv.oryzae(Xoo)and in Arabidopsis and tomato challenged with Pseudomonas syringae pv.tomato DC3000(Pst DC3000),whereas Os RALF27 did not enhance resistance.
文摘In the field of railway traction drive systems,voltage sensor intermittent faults can significantly impact the reliability and safety of the entire system.This paper proposes an online diagnosis method for detecting such faults using an Artificial Intelligence(AI)predictor based on a Nonlinear Autoregressive with eXogenous inputs(NARX)data structure.The model is trained efficiently using the Extreme Learning Machine(ELM)algorithm.The NARX model captures the dynamic characteristics of the voltage sensor data,enabling the AI predictor to learn complex nonlinear relationships.The ELM training method ensures rapid convergence and high accuracy.Through extensive experimental validation,the proposed method demonstrates high sensitivity to voltage sensor intermittent faults and robust performance under varying operating conditions.This approach offers a promising solution for enhancing the diagnostic capabilities of railway traction systems,ensuring timely fault detection and improving overall system reliability.
基金Supported by Universities Discipline Innovation and Intellectual Introduction Program Funded Projects(B08025)Key Projects of Basic Scienceand Technology Platform of Ministry of Education(505005)Ministry ofAgriculture Project"948"(2006-G8(4)-31-1)~~
文摘[Objective] The research aimed to map QTL for the sensitivity of the traits related outcrosssing of Japonica rice to exogenous GA3 and provide theoretical basis for breeding and improving the high-sensitivity sterile line.[Method] Taking Japonica rice Xiushui 79 and C bao and their recombinant inbred line population 260 lines as test materials,the sensitivity of 4 traits related outcrossing to Exogenous GA3 and their QTL mapping were studied by using composite interval mapping..[Result]Three QTLs,which cont...
基金Supported by Post-graduate Innovation Program of Guangxi(YCSZ2013007)~~
文摘Objective The purpose of this experiment was to investigate the effects of exogenous hormone factors on subculture multiplication and root induction of tis-suecultured seedlings in mulberry. [Method] The aseptic seedlings of Guisangyou 12 were used as the materials and the comparative experiment on subculture multi-plication and root induction used different kinds,concentrations and combinations of exogenous hormones. [Result] The hormone combination of 0.1 mg/L IBA＋1.5 mg/L 6-BA＋0.03 mg/L TDZ showed the best effects to bud multiplication, and the multiple of bud multiplication was 5.28. The effects of NAA was better than IBA and IAA on root induction. The hormone combination of 2.0 mg/L NAA＋1.0 mg/L PP333 was most suitable to the root induction, in which the rooting rate arrived to 100%, the root number was 7.01 and the root length was 1.38 cm on average. [Conclusion] The results wil provide some technical reference for large-scale propagation of mul-berry seedlings in vitro.
基金This paper was supported by the National Natural Science Foundation of China (No. 39970627) and the Key Project of State Department of Science Technology (2002BA515B05).
文摘The content of total sugar, sucrose, fructose and protein in the leaves of3-yr.-old Betula platyphylla was measured after the treatment by three exogenous sugar solutions(sucrose, fructose, glucose) and three high concentrations of CO_2 (700, 1 400, 2 100 μL/L·L^(-1))for about a month in 1998. The results showed that spraying three exogenous sugar solutionsincreased markedly the content of sugar and protein of leaves under 700 μL·L^(-1) and 1 400μL·L^(-1) CO_2 The effect of spraying exogenous sucrose solution was the best among the threeexogenous sugars. The treatment of spraying exogenous sugar solution and 2 100 μL·L^(-1) CO_2constrained the accumulation of total sugar and protein of leaves. There was no difference inprotein content of leaves when spraying glucose and fructose solutions under 700 μL·L^(-1) and 1400 μL·L^(-1) CO_2. The treatment of 2 100 μL·L^(-1) CO_2 concentration significantly increasedthe contents of total sugar, sucrose, fructose, and protein of leaves compared with that of the 700μL·L^(-1) and 1 400 μL·L^(-1) CO_2 except the plants spraying fructose solution. There waspositive correlation between the content of sugar of leaves and CO_2 concentration when sprayingsame exogenous sugar solution.
基金Supported by Agricultral Science and Technology Development Program of Shanxi Pvince(20150311010-1)Agricultral Science and Technology Development Program of Datong City(201468-2,2015099)~~
文摘[Objective] This study was conducted to reveal the effect of exogenous calcium （Ca） in mitigating the damage caused by NaCI stress to watermelon seedlings. [Method] To the liquid medium containing 100 mmol/L NaCI, CaSO4 was added to the final concentrations of 4, 6, 10 and 14 mmol/L. The morphological and physiological indices including plant height, stem diameter, number of leaves per plant, maximum leaf length, maximum leaf width, seedling fresh weight and dry weight, malondialdehyde （MDA） content, relative permeability of plasma membrane, ascorbic acid （AsA） content, free proline content, soluble sugar content and soluble protein content in leaves of the seedlings treated with above media for 10 d were measured. [Result] NaCI stress significantly inhibited the growth of watermelon seedlings. The membrane permeability and MDA content in leaves were significantly increased under NaCI stress, and the contents of proline, soluble sugar, soluble protein and AsA were increased to different extents. Exogenous CaSO4 influenced the morphological and physiological indices of seedlings under NaCI stress in a manner. Treated with 6 mmol/L CaSO4, the growth of seedlings under salinity was significantly improved; membrane permeability and MDA content were drastically reduced, the contents of proline, soluble sugar, soluble pro- tein and AsA in leaves were significantly increased. [Conclusion] Exogenous CaSO＋ alleviates lipid peroxidation and inhibition of seedling growth under NaCI stress by improving the abilities of antioxidation and osmotic adjustment, and 6 mmol/L CaSO4 showed the best effect.
基金Supported by General Projects of Basic Research of Natural Sciencein Jiangsu Universities(KJD180118)Excellent Course Construction Project of Plant Physiology in Jiangsu Province(2010)+1 种基金Innovative Team Building and Personnel Training Programs in Zhejiang Science and Technology Department(2010F20007)Outstanding Teaching Team Project in Nanjing Xiaozhuang College(4085024)~~
文摘[Objective] The paper was to study the effects of exogenous GA3 on seed germination and seedling growth of Salicornia europaea L.under salt stress.[Method] With the combination of different concentrations of NaCl（50,100,150,200,250,300,350,400 mmol/L）with 10 μmol /L GA3 treatments,the effects of exogenous GA3 on seed germination and seedling growth of S.europaea under salt stress were studied.[Result] Exogenous GA3 promoted the seed germination rate,germination capacity,germination index and seed vigor index of S.europaea under salt stress.Under the treatment of exogenous GA3,the root system vigor,the lengths of roots and stems and the salt-tolerance of S.europaea were higher than that of single salt stress treatment.[Conclusion] Within a certain concentration range,exogenous GA3 could alleviate the inhibition effects of salt stress on seed germination and seedling growth of S.europaea.
基金supported by the China Geological Survey Projects(Nos.20160272,20211379)the Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK0904)。
文摘The dynamic effect is a very important issue widely debated by scholars when studying the genetic and disaster-causing mechanisms of earthquake-triggered landslides.First,the dynamic effect mechanism and phenomena of earthquake-triggered landslides were summarized in this paper.Then,the primary types of dynamic effects were further used to interpret the Mogangling landslide in Moxi Town of Luding County,China.A field investigation,remote sensing,numerical calculation and theoretical analysis were carried out to illustrate the failure mechanism of slope rock masses affected by earthquakes.The interaction between seismic waves and slope rock masses and the induced dynamic effect of slope rock masses were primarily accounted for in the analysis.The slope topography,rock mass weathering and unloading characteristics,river erosion,regional seismogenic structure,and rock mass structure characteristics were also discussed.The results showed that the formation of the Mogangling landslide was mainly related to the high amplification effect of seismic acceleration and back slope effects,interface dynamic stress effects,and double-sided slope effects of seismic waves caused by the catastrophic Ms 7.75 Moxi Earthquake in 1786.The principles for the site and route selection of large-scale infrastructure in the planning stage and the scientific prevention of seismic geological disasters were proposed on the basis of the dynamic effect of earthquake-induced landslides.
文摘The mechanisms of sex determination and the influence of exogenous factors on sex differentiation in crustacean were reviewed in the paper.Most of crustecea have not obviously sex chromosome.Androgenic gland was reported as the most important sex differentiation factors,implanting or cuting AG can change the sexal characterization of larval in crustacean.Although sex differentiation of crustacean is determined by gene,it is affected by exogenous factors such as parasite,photoperiod,temperature or hormone.Most cultured species have different body weight and length between male and female,this can be used in aquaculture to produce all male or female crusteceans to improve the production.
