Due to the heterogeneity of rock masses and the variability of in situ stress,the traditional linear inversion method is insufficiently accurate to achieve high accuracy of the in situ stress field.To address this cha...Due to the heterogeneity of rock masses and the variability of in situ stress,the traditional linear inversion method is insufficiently accurate to achieve high accuracy of the in situ stress field.To address this challenge,nonlinear stress boundaries for a numerical model are determined through regression analysis of a series of nonlinear coefficient matrices,which are derived from the bubbling method.Considering the randomness and flexibility of the bubbling method,a parametric study is conducted to determine recommended ranges for these parameters,including the standard deviation(σb)of bubble radii,the non-uniform coefficient matrix number(λ)for nonlinear stress boundaries,and the number(m)and positions of in situ stress measurement points.A model case study provides a reference for the selection of these parameters.Additionally,when the nonlinear in situ stress inversion method is employed,stress distortion inevitably occurs near model boundaries,aligning with the Saint Venant's principle.Two strategies are proposed accordingly:employing a systematic reduction of nonlinear coefficients to achieve high inversion accuracy while minimizing significant stress distortion,and excluding regions with severe stress distortion near the model edges while utilizing the central part of the model for subsequent simulations.These two strategies have been successfully implemented in the nonlinear in situ stress inversion of the Xincheng Gold Mine and have achieved higher inversion accuracy than the linear method.Specifically,the linear and nonlinear inversion methods yield root mean square errors(RMSE)of 4.15 and 3.2,and inversion relative errors(δAve)of 22.08%and 17.55%,respectively.Therefore,the nonlinear inversion method outperforms the traditional multiple linear regression method,even in the presence of a systematic reduction in the nonlinear stress boundaries.展开更多
In the aerospace field, residual stress directly affects the strength, fatigue life and dimensional stability of thin-walled structural components, and is a key factor to ensure flight safety and reliability. At prese...In the aerospace field, residual stress directly affects the strength, fatigue life and dimensional stability of thin-walled structural components, and is a key factor to ensure flight safety and reliability. At present, research on residual stress at home and abroad mainly focuses on the optimization of traditional detection technology, stress control of manufacturing process and service performance evaluation, among which research on residual stress detection methods mainly focuses on the improvement of the accuracy, sensitivity, reliability and other performance of existing detection methods, but it still faces many challenges such as extremely small detection range, low efficiency, large error and limited application range.展开更多
To investigate the residual stress distribution and its influence on machining deformation in 6061-T651 aluminum alloy plates,this paper uses the crack compliance method to study the residual stress characteristics of...To investigate the residual stress distribution and its influence on machining deformation in 6061-T651 aluminum alloy plates,this paper uses the crack compliance method to study the residual stress characteristics of 6061-T651 aluminum alloy plates with a thickness of 75 mm produced by two domestic manufacturers in China.The results indicate that both types of plates exhibit highly consistent and symmetrical M-shaped residual stress profile along the thickness direction,manifested as surface layer compression and core tension.The strain energy density across all specimens ranges from 1.27 kJ/m^(3)to 1.43 kJ/m^(3).Machining deformation simulations of an aerospace component incorporating these measured stresses showed minimal final deformation difference between the material sources,with a maximum deviation of only 0.009 mm across specimens.These findings provide critical data for material selection and deformation control in aerospace manufacturing.展开更多
This study proposes an alternative calculation mode for stresses on the slip surface(SS).The calculation of the normal stress(NS)on the SS involves examining its composition and expanding its unknown using the Taylor ...This study proposes an alternative calculation mode for stresses on the slip surface(SS).The calculation of the normal stress(NS)on the SS involves examining its composition and expanding its unknown using the Taylor series.This expansion enables the reasonable construction of a function describing the NS on the SS.Additionally,by directly incorporating the nonlinear Generalized Hoke-Brown(GHB)strength criterion and utilizing the slope factor of safety(FOS)definition,a function of the shear stress on the SS is derived.This function considers the mutual feedback mechanism between the NS and strength parameters of the SS.The stress constraints conditions are then introduced at both ends of the SS based on the spatial stress relation of one point.Determining the slope FOS and stress solution for the SS involves considering the mechanical equilibrium conditions and the stress constraint conditions satisfied by the sliding body.The proposed approach successfully simulates the tension-shear stress zone near the slope top and provides an intuitive description of the concentration effect of compression-shear stress of the SS near the slope toe.Furthermore,compared to other methods,the present method demonstrates superior processing capabilities for the embedded nonlinear GHB strength criterion.展开更多
The precision of dynamic reserve calculations in gas reservoirs is crucial for the rational and efficient development of oil and gas fields and the formulation of gas well production plans.The Shaximiao gas reservoir ...The precision of dynamic reserve calculations in gas reservoirs is crucial for the rational and efficient development of oil and gas fields and the formulation of gas well production plans.The Shaximiao gas reservoir in the ZT block of northwestern Sichuan is densely packed and highly heterogeneous,featuring complex gas-water distribution,substantial variations in test production among gas wells,and a rapid decline rate.To precisely determine the dynamic reserves of these tight water-bearing gas wells,this study focuses on the water-tight gas reservoirs in the ZT block of northwestern Sichuan,conducting core X-ray diffraction,constant-rate mercury injection,and reservoir rock stress sensitivity experiments.Utilizing the experimental findings,the porosity and permeability of the rock samples under effective stress conditions are adjusted via binary linear regression.These adjusted parameters are then incorporated into the water-sealed gas material balance method,thereby establishing a novel approach for calculating dynamic reserves in water-tight gas reservoirs under stress sensitivity conditions.The results show that:(1)the rock porosity ranges from 6.08%to 10.22%,permeability ranges from 0.035 mD to 0.547 mD,clay mineral content ranges from 6.58%to 19.14%,pore radius distribution ranges from 90μm to 180μm,throat radius distribution ranges from 0.61μm to 3.41μm,with significant differences in throat distribution,indicating poor reservoir fluid flow capacity and strong tightness;(2)after aging experiments,rock samples exhibit plastic deformation,with porosity and permeability unable to fully recover after pressure relief.The stress sensitivity curve of rock samples shows a two-stage characteristic,with moderate to strong stress sensitivity;(3)porosity stress sensitivity is mainly influenced by pore radius and mineral composition-larger pore radius and higher clay content lead to stronger stress sensitivity,with porosity loss rates ranging from 8.26%to 23.69%.Permeability stress sensitivity is mainly influenced by throat radius and mineral composition-smaller throat radius and higher clay content result in stronger stress sensitivity,with permeability loss rates ranging from 47.91%to 62.03%;(4)a comparative analysis between the traditional dynamic reserve calculation method for gas wells and the new method considering stress sensitivity shows a relative error between 0.90%and 2.41%,with the new method demonstrating better accuracy.This study combines physical experimental results with an effective stress model of reservoir rocks to develop a new method for calculating dynamic reserves of water-bearing tight gas reservoirs under effective stress conditions,providing experimental data and example calculation results to support subsequent dynamic evaluation of gas reservoirs and the establishment of rational well allocation plans.展开更多
In this paper,we propose a multiphysics finite element method for a nonlinear poroelasticity model with nonlinear stress-strain relation.Firstly,we reformulate the original problem into a new coupled fluid system-a ge...In this paper,we propose a multiphysics finite element method for a nonlinear poroelasticity model with nonlinear stress-strain relation.Firstly,we reformulate the original problem into a new coupled fluid system-a generalized nonlinear Stokes problem of displacement vector field related to pseudo pressure and a diffusion problem of other pseudo pressure fields.Secondly,a fully discrete multiphysics finite element method is performed to solve the reformulated system numerically.Thirdly,existence and uniqueness of the weak solution of the reformulated model and stability analysis and optimal convergence order for the multiphysics finite element method are proven theoretically.Lastly,numerical tests are given to verify the theoretical results.展开更多
Fatigue failure caused by vibration is the most common type of pipeline failure.The core of this research is to obtain the nonlinear dynamic stress of a pipeline system accurately and efficiently,a topic that needs to...Fatigue failure caused by vibration is the most common type of pipeline failure.The core of this research is to obtain the nonlinear dynamic stress of a pipeline system accurately and efficiently,a topic that needs to be explored in the existing literature.The shell theory can better simulate the circumferential stress distribution,and thus the Mindlin-Reissner shell theory is used to model the pipeline.In this paper,the continuous pipeline system is combined with clamps through modal expansion for the first time,which realizes the coupling problem between a shell and a clamp.While the Bouc-Wen model is used to simulate the nonlinear external force generated by a clamp,the nonlinear coupling characteristics of the system are effectively captured.Then,the dynamic equation of the clamp-pipeline system is established according to the Lagrange energy equation.Based on the resonance frequency and stress amplitude obtained from the experiment,the nonlinear parameters of the clamp are identified with the semi-analytical method(SAM)and particle swarm optimization(PSO)algorithm.This study provides a theoretical basis for the clamp-pipeline system and an efficient and universal solution for stress prediction and analysis of pipelines in engineering.展开更多
The surrounding rock is prone to large-scale loosening and failure after the excavation of shallow large-span caverns because of the thin overlying strata and large cross-section span.The rational design of bolt suppo...The surrounding rock is prone to large-scale loosening and failure after the excavation of shallow large-span caverns because of the thin overlying strata and large cross-section span.The rational design of bolt support is very important to the safety control of surrounding rock as a common support means.The control mechanism and design method of bolt support for shallow-buried large-span caverns is carried out.The calculation method of bolt prestress and length based on arched failure and collapsed failure mode is established.The influence mechanism of different influencing factors on the bolt prestress and length is clarified.At the same time,the constant resistance energy-absorbing bolt with high strength and high toughness is developed,and the comparative test of mechanical properties is carried out.On this basis,the design method of high prestressed bolt support for shallow-buried large-span caverns is put forward,and the field test is carried out in Qingdao metro station in China.The monitoring results show that the maximum roof settlement is 6.8 mm after the new design method is adopted,and the effective control of the shallow-buried large-span caverns is realized.The research results can provide theoretical and technical support for the safety control of shallow-buried large-span caverns.展开更多
Existing evidence has demonstrated the association between exposure to volatile organic compounds(VOCs)and osteoporosis(OP)risk,but the underlying mechanistic framework remains unclear.This study aimed to explore pote...Existing evidence has demonstrated the association between exposure to volatile organic compounds(VOCs)and osteoporosis(OP)risk,but the underlying mechanistic framework remains unclear.This study aimed to explore potential pathways using adverse outcome pathway(AOP)analysis,and evidence this association in middle-to-old-aged American adults using the updated National Health and Nutrition Examination Survey data.Multivariable-adjusted general linear and weighted quantile sum models were employed to analyze associations of VOC metabolites(VOCMs),representing internal VOCs exposure levels,with OP-related phenotypes.An AOP framework based on network analysis was developed by extracting target genes and phenotypes.Among 3555 American adults aged≥40 years(539 OP participants),we found that increasing urinary 3-and 4-methylhippuric acid,N-acetyl-S-(n-propyl)-l-cysteine(BPMA),and N-acetyl-S-(3-hydroxypropyl)-l-cysteine were associated with elevated OP odds with odds ratios(ORs)(95%confidence intervals,95%CIs)being 1.254(1.016 to 1.548),1.182(1.014 to 1.377),and 1.244(1.029 to 1.505),respectively,per standard deviation.Urinary BPMA and N-acetyl-S-(2-cyanoethyl)-l-cysteine were inversely associated with lumbar spine bone mineral density(BMD),while urinary N-acetyl-S-(2-hydroxypropyl)-l-cysteine was positively associated with hip BMD.Additionally,OP odds increased by 46.0%(95%CI:3.9%to 105.1%)per quartile increment in the VOC mixture.AOP analysis identified 53 target genes and 9 target phenotypes,and 5 of 9 target phenotypes were oxidative stress(OS)-related.Literature and the“AOP 482”framework implied the core role of OS in the VOC exposure and prevalent OP association,with the interleukin-6 as themolecular initiating event.Our findings provided a theoretical basis for further investigation.展开更多
Axial chain rockbursts(ACRs)repeatedly occur in deep tunnels during drilling and blasting methodology(D&B)within locked-in stress zones,severely hindering construction progress.In extremely cases,ACRs can persist ...Axial chain rockbursts(ACRs)repeatedly occur in deep tunnels during drilling and blasting methodology(D&B)within locked-in stress zones,severely hindering construction progress.In extremely cases,ACRs can persist for 7−10 d and affect areas exceeding 20 m along tunnel axis.Through integrated geological investigations and microseismic(MS)monitoring,the geological characteristics,MS activity patterns,and formation mechanisms of ACRs were analyzed.In tectonically active regions,locked-in stress zones arise from interactions between multiple structural planes.Blasting dynamic disturbances during tunnel excavation in these zones trigger early slippage along structural planes and fractures in the surrounding rock,with MS events developing ahead of the working face.High-energy MS events dominate during the development and occurrence stages of ACRs,extending 20−30 m(3−4 tunnel diameters)ahead of the working face.Following the ACRs,low-energy MS events primarily occur behind the working face.Tensile fracturing is the predominant failure mode during ACRs.Shear and mixed fractures primarily occur within the ACRs zone during the intra-ACR phase.Monitoring MS event locations ahead of the working face provides a reliable approach for prewarning potential ACR-prone zones.展开更多
The presence of residual stresses in materials or engineering structures can significantly influence their mechanical per-formance.Accurate measurement of residual stresses is of great importance to ensure their in-se...The presence of residual stresses in materials or engineering structures can significantly influence their mechanical per-formance.Accurate measurement of residual stresses is of great importance to ensure their in-service reliability.Although numerous instrumented indentation methods have been proposed to evaluate residual stresses,the majority of them require a stress-free reference sample as a comparison benchmark,thereby limiting their applicability in scenarios where obtaining stress-free reference samples is challenging.In this work,through a number of finite element simulations,it was found that the loading exponent of the loading load-depth curve and the recovered depth during unloading are insensitive to residual stresses.The loading curve of the stress-free specimen was virtually reconstructed using such stress-insensitive parameters extracted from the load-depth curves of the stressed state,thus eliminating the requirement for stress-free reference samples.The residual stress was then correlated with the fractional change in loading work between stressed and stress-free loading curves through dimensional analysis and finite element simulations.Based on this correlation,an instrumented sharp indentation method for measuring equibiaxial residual stress without requiring a stress-free specimen was established.Both numerical and experimental verifications were carried out to demonstrate the accuracy and reliability of the newly proposed method.The maximum relative error and absolute error in measured residual stresses are typically within±20%and±20 MPa,respectively.展开更多
Hydraulic fracturing plays a critical role in enhancing shale gas production in deep shale reservoirs.Conventional hydraulic fracturing simulation methods rely on prefabricated grids,which can be hindered by the chall...Hydraulic fracturing plays a critical role in enhancing shale gas production in deep shale reservoirs.Conventional hydraulic fracturing simulation methods rely on prefabricated grids,which can be hindered by the challenge of being computationally overpowered.This study proposes an efficient fracturing simulator to analyze fracture morphology during hydraulic fracturing processes in deep shale gas reservoirs.The simulator integrates the boundary element displacement discontinuity method and the finite volume method to model the fluid-solid coupling process by employing a pseudo-3D fracture model to calculate the fracture height.In particular,the Broyden iteration method was introduced to improve the computational efficiency and model robustness;it achieved a 46.6%reduction in computation time compared to the Newton-Raphson method.The influences of horizontal stress differences,natural fracture density,and natural fracture angle on the modified zone of the reservoir were simulated,and the following results were observed.(1)High stress difference reservoirs have smaller stimulated reservoir area than low stress difference reservoirs.(2)A higher natural fracture angle resulted in larger modification zones at low stress differences,while the effect of a natural fracture angle at high stress differences was not significant.(3)High-density and long natural fracture zones played a significant role in enhancing the stimulated reservoir area.These findings are critical for comprehending the impact of geological parameters on deep shale reservoirs.展开更多
The surrounding rock of the soft rock roadway is seriously deformed and damaged under the superposition of mining stress and fault tectonic stress.In this paper,taking the No.232206 intake roadway in Meihuajing Coal M...The surrounding rock of the soft rock roadway is seriously deformed and damaged under the superposition of mining stress and fault tectonic stress.In this paper,taking the No.232206 intake roadway in Meihuajing Coal Mine as the engineering background,the deformation and failure law of the surrounding rock of the roadway in different fault protection pillar widths were obtained by numerical simulation method.On this basis,the mechanical model of the roadway under the action of hanging wall overburden migration and fault slip in normal faults was established,and the energy-driven mechanism of large deformation of the surrounding rock of the roadway was revealed.The ratio T of the energy applying on anchoring surrounding rock to the resistant energy of the anchored surrounding rock was defined as the criterion for the deformation of the roadway.Finally,it was calculated according to the actual working conditions on site,and the control method of“stress relief-support reinforcement”was used to support the roadway with the risk of large deformation.The on-site monitoring results show that the control effect of the surrounding rock of the roadway is obvious.展开更多
Accurate prediction of coal and gas outburst(CGO)hazards is paramount in gas disaster prevention and control.This paper endeavors to overcome the constraints posed by traditional prediction indexes when dealing with C...Accurate prediction of coal and gas outburst(CGO)hazards is paramount in gas disaster prevention and control.This paper endeavors to overcome the constraints posed by traditional prediction indexes when dealing with CGO incidents under low gas pressure conditions.In pursuit of this objective,we have studied and established a mechanical model of the working face under abnormal stress and the excitation energy conditions of CGO,and proposed a method for predicting the risk of CGO under abnormal stress.On site application verification shows that when a strong outburst hazard level prediction is issued,there is a high possibility of outburst disasters occurring.In one of the three locations where we predicted strong outburst hazards,a small outburst occurred,and the accuracy of the prediction was higher than the traditional drilling cuttings index S and drilling cuttings gas desorption index q.Finally,we discuss the mechanism of CGO under the action of stress anomalies.Based on the analysis of stress distribution changes and energy accumulation characteristics of coal under abnormal stress,this article believes that the increase in outburst risk caused by high stress abnormal gradient is mainly due to two reasons:(1)The high stress abnormal gradient leads to an increase in the plastic zone of the coal seam.After the working face advances,it indirectly leads to an increase in the gas expansion energy that can be released from the coal seam before reaching a new stress equilibrium.(2)Abnormal stress leads to increased peak stress of coal body in front of working face.When coal body in elastic area transforms to plastic area,its failure speed is accelerated,which induces accelerated gas desorption and aggravates the risk of outburst.展开更多
Protein aggregates,mitochondrial import stress and neurodegenerative disorders:A salient hallmark of several neurodegenerative diseases,including Parkinson’s disease,is the abundance of protein aggregates(Goiran et a...Protein aggregates,mitochondrial import stress and neurodegenerative disorders:A salient hallmark of several neurodegenerative diseases,including Parkinson’s disease,is the abundance of protein aggregates(Goiran et al.,2022).This molecular event is believed to lead to activation of stress pathways ultimately resulting in cellular dysfunction(Eldeeb et al.,2022).Accordingly,many lines of research investigations focused on dampening the formation of protein aggregates or augmenting the clearance of protein aggregates as a potential therapeutic strategy to counteract the progression of neurodegenerative diseases,albeit with little success(Costa-Mattioli and Walter,2020).Cell stress cues such as the accumulation of protein aggregates lead to the activation of stress response pathways that aid cells in responding to the damage.Despite the notion that the transient activation of these pathways helps cells cope with stressors,persistent activation can induce unwanted apoptosis of cells and reduce overall tissue strength as well as lead to an accumulation of aggregation-prone proteins(Hetz and Papa,2018).Mutations in proteins involved in stress signaling termination can cause conditions like ataxia and early-onset dementia(Conroy et al.,2014).Therefore,it is crucial for stress response signaling to be turned off once conditions have improved.Nevertheless,the mechanisms by which cells silence these signals are still elusive.展开更多
In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to ...In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.展开更多
Drought stress is a serious natural challenge for tea plants that significantly affects tea yield and quality.miR171s play critical roles in plant stress responses,however,their role in drought stress tolerance in tea...Drought stress is a serious natural challenge for tea plants that significantly affects tea yield and quality.miR171s play critical roles in plant stress responses,however,their role in drought stress tolerance in tea plants(Camellia sinensis)is poorly understood.This study experimentally verified the expression patterns of csn-miR171b-3p_2 and its target,scarecrow-like(SCL).We found that csn-miR171b-3p_2 could target and regulate CsSCL6-4 to play an important role in the defense against drought stress in tea plants.CsSCL6-4 is located in the nucleus and is selfactivated in vivo.In addition,we obtained 819 putative binding regions of CsSCL6-4 using DNA affinity purification sequencing analysis,which were assigned to 786 different genes,four of which were drought-resistant genes(CsPrx,CsSDR,CsFAD7,and CsCER1).Yeast one-hybrid and dual-luciferase reporter assays revealed that CsSCL6-4 directly promoted the expression of these four drought resistance genes by binding motifs 1/2/3 in their promoter regions.Both overexpression and suppression of CsSCL6-4 proved that CsSCL6-4 participated in the defense against drought stress in tea plants by regulating the expression of CsPrx,CsSDR,CsFAD7,and CsCER1.In addition,suppression of csn-miR171b-3p_2 expression significantly increased the expression of CsSCL6-4 and activated CsSCL6-4-bound gene transcription under drought stress.Therefore,the csn-miR171b-3p_2-CsSCL6-4 module participates in tea plant resistance to drought stress by promoting the expression of drought resistance genes.Our results revealed the function of csn-miR171b-3p_2 in tea plants and provided new insights into the mechanism of tea plant resistance to drought stress.展开更多
The unfolded protein response is a cellular pathway activated to maintain proteostasis and prevent cell death when the endoplasmic reticulum is overwhelmed by unfolded proteins.However,if the unfolded protein response...The unfolded protein response is a cellular pathway activated to maintain proteostasis and prevent cell death when the endoplasmic reticulum is overwhelmed by unfolded proteins.However,if the unfolded protein response fails to restore endoplasmic reticulum homeostasis,it can trigger proinflammatory and pro-death signals,which are implicated in various malignancies and are currently being investigated for their role in retinal degenerative diseases.This paper reviews the role of the unfolded protein responsein addressing endoplasmic reticulumstress in retinal degenerative diseases.The accumulation of ubiquitylated misfolded proteins can lead to rapid destabilization of the proteome and cellular demise.Targeting endoplasmic reticulum stress to alleviate retinal pathologies involves multiple strategies,including the use of chemical chaperones such as 4-phenylbutyric acid and tauroursodeoxycholic acid,which enhance protein folding and reduce endoplasmic reticulum stress.Small molecule modulators that influence endoplasmic reticulum stress sensors,including those that increase the expression of the endoplasmic reticulum stress regulator X-box binding protein 1,are also potential therapeutic agents.Additionally,inhibitors of the RNAse activity of inositol-requiring transmembrane kinase/endoribonuclease 1,a key endoplasmic reticulum stress sensor,represent another class of drugs that could prevent the formation of toxic aggregates.The activation of nuclear receptors,such as PPAR and FXR,may also help mitigate ER stress.Furthermore,enhancing proteolysis through the induction of autophagy or the inhibition of deubiquitinating enzymes can assist in clearing misfolded proteins.Combination treatments that involve endoplasmicreticulum-stress-targeting drugs and gene therapies are also being explored.Despite these potential therapeutic strategies,significant challenges remain in targeting endoplasmic reticulum stress for the treatment of retinal degeneration,and further research is essential to elucidate the mechanisms underlying human retinal diseases and to develop effective,well-tolerated drugs.The use of existing drugs that target inositol-requiring transmembrane kinase/endoribonuclease 1 and X-box binding protein 1 has been associated with adverse side effects,which have hindered their clinical translation.Moreover,signaling pathways downstream of endoplasmic reticulum stress sensors can contribute to therapy resistance.Addressing these limitations is crucial for developing drugs that can be effectively used in treating retinal dystrophies.In conclusion,while the unfolded protein response is a promising therapeutic target in retinal degenerative diseases,additional research and development efforts are imperative to overcome the current limitations and improve patient outcomes.展开更多
N6-methyladenosine(m^(6)A)modification,the most abundant internal modification in messenger RNA(mRNA)and long non-coding RNA(lncRNA),has emerged as a critical epitranscriptomic regulatory mechanism in eukaryotes.While...N6-methyladenosine(m^(6)A)modification,the most abundant internal modification in messenger RNA(mRNA)and long non-coding RNA(lncRNA),has emerged as a critical epitranscriptomic regulatory mechanism in eukaryotes.While the importance of m^(6)A modification in various biological processes has been recognized,a comprehensive understanding of its diverse roles in plant biology and agricultural applications remains fragmented.This review analyzes recent advances inm^(6)A modification's biological functions in plants.m^(6)A modification plays crucial roles in multiple aspects of plant life,including seed germination,organ development,and reproductive structure formation.Furthermore,m^(6)A has been found to significantly influence plant responses to environmental stresses,including salt,drought,temperature,and heavy metal exposure.We also uncover m^(6)A involvement in important agricultural traits.This review provides insights into the mechanistic understanding of m^(6)A modification in plants and highlights its applications in agricultural improvement,offering a foundation for future research in crop enhancement and stress resistance.展开更多
Heavy metal(HM)contamination severely impacts global agricultural production.HMs toxicity effectively damaged the physiological functions such as imbalanced redox homeostasis,altered antioxidant enzyme activity,damage...Heavy metal(HM)contamination severely impacts global agricultural production.HMs toxicity effectively damaged the physiological functions such as imbalanced redox homeostasis,altered antioxidant enzyme activity,damage root system architecture,hindered photosynthetic apparatus,cellular toxicity,restricted mineral accumulation,and changed the metabolite production.Using phytohormones may be a successful strategy for enhancing and stimulating plant tolerance to HMs toxicity without affecting the environment.Melatonin(MT),a novel plant growth regulator,and powerful antioxidant molecule,enhances plant resilience to HMs stress by enhancing seedling growth,protecting the photosynthetic system,increasing nutritional status,balanced redox homeostasis,and restricting HMs accumulation from root to shoot.In addition,MT enhances the activity of antioxidant enzymes and triggers the ascorbate-glutathione(AsA-GSH)cycle,which helps remove excessive ROS.MT improves RuBisCO activity to improve photosynthesis and reduce the breakdown of chlorophyll.To identify future research needs,it is crucial to understand the comprehensive and intricate regulatory mechanisms of exogenous and endogenous MT-mediated reduction of heavy metal toxicity in plants.Melatonin has several functions,and this review sheds light on those functions and the molecular processes by which it alleviates HMs toxicity.More research is needed to fully understand how melatonin affects plant tolerance to heavy metals stress.展开更多
基金funded by the National Key R&D Program of China(Grant No.2022YFC2903904)the National Natural Science Foundation of China(Grant Nos.51904057 and U1906208).
文摘Due to the heterogeneity of rock masses and the variability of in situ stress,the traditional linear inversion method is insufficiently accurate to achieve high accuracy of the in situ stress field.To address this challenge,nonlinear stress boundaries for a numerical model are determined through regression analysis of a series of nonlinear coefficient matrices,which are derived from the bubbling method.Considering the randomness and flexibility of the bubbling method,a parametric study is conducted to determine recommended ranges for these parameters,including the standard deviation(σb)of bubble radii,the non-uniform coefficient matrix number(λ)for nonlinear stress boundaries,and the number(m)and positions of in situ stress measurement points.A model case study provides a reference for the selection of these parameters.Additionally,when the nonlinear in situ stress inversion method is employed,stress distortion inevitably occurs near model boundaries,aligning with the Saint Venant's principle.Two strategies are proposed accordingly:employing a systematic reduction of nonlinear coefficients to achieve high inversion accuracy while minimizing significant stress distortion,and excluding regions with severe stress distortion near the model edges while utilizing the central part of the model for subsequent simulations.These two strategies have been successfully implemented in the nonlinear in situ stress inversion of the Xincheng Gold Mine and have achieved higher inversion accuracy than the linear method.Specifically,the linear and nonlinear inversion methods yield root mean square errors(RMSE)of 4.15 and 3.2,and inversion relative errors(δAve)of 22.08%and 17.55%,respectively.Therefore,the nonlinear inversion method outperforms the traditional multiple linear regression method,even in the presence of a systematic reduction in the nonlinear stress boundaries.
文摘In the aerospace field, residual stress directly affects the strength, fatigue life and dimensional stability of thin-walled structural components, and is a key factor to ensure flight safety and reliability. At present, research on residual stress at home and abroad mainly focuses on the optimization of traditional detection technology, stress control of manufacturing process and service performance evaluation, among which research on residual stress detection methods mainly focuses on the improvement of the accuracy, sensitivity, reliability and other performance of existing detection methods, but it still faces many challenges such as extremely small detection range, low efficiency, large error and limited application range.
基金supported in part by the National Natural Science Foundation of China(Nos.61201048,61107063)the National Science and Technology Major Project(No.2017-VI-001-0094).
文摘To investigate the residual stress distribution and its influence on machining deformation in 6061-T651 aluminum alloy plates,this paper uses the crack compliance method to study the residual stress characteristics of 6061-T651 aluminum alloy plates with a thickness of 75 mm produced by two domestic manufacturers in China.The results indicate that both types of plates exhibit highly consistent and symmetrical M-shaped residual stress profile along the thickness direction,manifested as surface layer compression and core tension.The strain energy density across all specimens ranges from 1.27 kJ/m^(3)to 1.43 kJ/m^(3).Machining deformation simulations of an aerospace component incorporating these measured stresses showed minimal final deformation difference between the material sources,with a maximum deviation of only 0.009 mm across specimens.These findings provide critical data for material selection and deformation control in aerospace manufacturing.
基金Project(52278380)supported by the National Natural Science Foundation of ChinaProject(2023JJ30670)supported by the National Science Foundation of and Technology Major Project of Hunan Province,China。
文摘This study proposes an alternative calculation mode for stresses on the slip surface(SS).The calculation of the normal stress(NS)on the SS involves examining its composition and expanding its unknown using the Taylor series.This expansion enables the reasonable construction of a function describing the NS on the SS.Additionally,by directly incorporating the nonlinear Generalized Hoke-Brown(GHB)strength criterion and utilizing the slope factor of safety(FOS)definition,a function of the shear stress on the SS is derived.This function considers the mutual feedback mechanism between the NS and strength parameters of the SS.The stress constraints conditions are then introduced at both ends of the SS based on the spatial stress relation of one point.Determining the slope FOS and stress solution for the SS involves considering the mechanical equilibrium conditions and the stress constraint conditions satisfied by the sliding body.The proposed approach successfully simulates the tension-shear stress zone near the slope top and provides an intuitive description of the concentration effect of compression-shear stress of the SS near the slope toe.Furthermore,compared to other methods,the present method demonstrates superior processing capabilities for the embedded nonlinear GHB strength criterion.
基金supported by CNPC Southwest Oil and Gas Field Branch's 2023 Scientific Research Program Project(20230303-14).
文摘The precision of dynamic reserve calculations in gas reservoirs is crucial for the rational and efficient development of oil and gas fields and the formulation of gas well production plans.The Shaximiao gas reservoir in the ZT block of northwestern Sichuan is densely packed and highly heterogeneous,featuring complex gas-water distribution,substantial variations in test production among gas wells,and a rapid decline rate.To precisely determine the dynamic reserves of these tight water-bearing gas wells,this study focuses on the water-tight gas reservoirs in the ZT block of northwestern Sichuan,conducting core X-ray diffraction,constant-rate mercury injection,and reservoir rock stress sensitivity experiments.Utilizing the experimental findings,the porosity and permeability of the rock samples under effective stress conditions are adjusted via binary linear regression.These adjusted parameters are then incorporated into the water-sealed gas material balance method,thereby establishing a novel approach for calculating dynamic reserves in water-tight gas reservoirs under stress sensitivity conditions.The results show that:(1)the rock porosity ranges from 6.08%to 10.22%,permeability ranges from 0.035 mD to 0.547 mD,clay mineral content ranges from 6.58%to 19.14%,pore radius distribution ranges from 90μm to 180μm,throat radius distribution ranges from 0.61μm to 3.41μm,with significant differences in throat distribution,indicating poor reservoir fluid flow capacity and strong tightness;(2)after aging experiments,rock samples exhibit plastic deformation,with porosity and permeability unable to fully recover after pressure relief.The stress sensitivity curve of rock samples shows a two-stage characteristic,with moderate to strong stress sensitivity;(3)porosity stress sensitivity is mainly influenced by pore radius and mineral composition-larger pore radius and higher clay content lead to stronger stress sensitivity,with porosity loss rates ranging from 8.26%to 23.69%.Permeability stress sensitivity is mainly influenced by throat radius and mineral composition-smaller throat radius and higher clay content result in stronger stress sensitivity,with permeability loss rates ranging from 47.91%to 62.03%;(4)a comparative analysis between the traditional dynamic reserve calculation method for gas wells and the new method considering stress sensitivity shows a relative error between 0.90%and 2.41%,with the new method demonstrating better accuracy.This study combines physical experimental results with an effective stress model of reservoir rocks to develop a new method for calculating dynamic reserves of water-bearing tight gas reservoirs under effective stress conditions,providing experimental data and example calculation results to support subsequent dynamic evaluation of gas reservoirs and the establishment of rational well allocation plans.
基金Supported by the National Natural Science Foundation of China(Grant Nos.12371393,11971150 and 11801143)Natural Science Foundation of Henan Province(Grant No.242300421047).
文摘In this paper,we propose a multiphysics finite element method for a nonlinear poroelasticity model with nonlinear stress-strain relation.Firstly,we reformulate the original problem into a new coupled fluid system-a generalized nonlinear Stokes problem of displacement vector field related to pseudo pressure and a diffusion problem of other pseudo pressure fields.Secondly,a fully discrete multiphysics finite element method is performed to solve the reformulated system numerically.Thirdly,existence and uniqueness of the weak solution of the reformulated model and stability analysis and optimal convergence order for the multiphysics finite element method are proven theoretically.Lastly,numerical tests are given to verify the theoretical results.
基金Project supported by the National Science and Technology Major Project(No.J2019-I-0008-0008)the National Natural Science Foundation of China(No.52305096)the Chinese Postdoctoral Science Foundation(No.GZB20230117)。
文摘Fatigue failure caused by vibration is the most common type of pipeline failure.The core of this research is to obtain the nonlinear dynamic stress of a pipeline system accurately and efficiently,a topic that needs to be explored in the existing literature.The shell theory can better simulate the circumferential stress distribution,and thus the Mindlin-Reissner shell theory is used to model the pipeline.In this paper,the continuous pipeline system is combined with clamps through modal expansion for the first time,which realizes the coupling problem between a shell and a clamp.While the Bouc-Wen model is used to simulate the nonlinear external force generated by a clamp,the nonlinear coupling characteristics of the system are effectively captured.Then,the dynamic equation of the clamp-pipeline system is established according to the Lagrange energy equation.Based on the resonance frequency and stress amplitude obtained from the experiment,the nonlinear parameters of the clamp are identified with the semi-analytical method(SAM)and particle swarm optimization(PSO)algorithm.This study provides a theoretical basis for the clamp-pipeline system and an efficient and universal solution for stress prediction and analysis of pipelines in engineering.
基金Project(2023YFC3805700) supported by the National Key Research and Development Program of ChinaProjects(42477166,42277174) supported by the National Natural Science Foundation of China+2 种基金Project(2024JCCXSB01) supported by the Fundamental Research Funds for the Central Universities,ChinaProject(KFJJ24-01M) supported by the State Key Laboratory of Explosion Science and Safety Protection,Beijing Institute of Technology,ChinaProject(HLCX-2024-04) supported by the Open Foundation of Collaborative Innovation Center of Green Development and Ecological Restoration of Mineral Resources,China。
文摘The surrounding rock is prone to large-scale loosening and failure after the excavation of shallow large-span caverns because of the thin overlying strata and large cross-section span.The rational design of bolt support is very important to the safety control of surrounding rock as a common support means.The control mechanism and design method of bolt support for shallow-buried large-span caverns is carried out.The calculation method of bolt prestress and length based on arched failure and collapsed failure mode is established.The influence mechanism of different influencing factors on the bolt prestress and length is clarified.At the same time,the constant resistance energy-absorbing bolt with high strength and high toughness is developed,and the comparative test of mechanical properties is carried out.On this basis,the design method of high prestressed bolt support for shallow-buried large-span caverns is put forward,and the field test is carried out in Qingdao metro station in China.The monitoring results show that the maximum roof settlement is 6.8 mm after the new design method is adopted,and the effective control of the shallow-buried large-span caverns is realized.The research results can provide theoretical and technical support for the safety control of shallow-buried large-span caverns.
基金supported by the National Natural Science Foundation of China(No.82273711).
文摘Existing evidence has demonstrated the association between exposure to volatile organic compounds(VOCs)and osteoporosis(OP)risk,but the underlying mechanistic framework remains unclear.This study aimed to explore potential pathways using adverse outcome pathway(AOP)analysis,and evidence this association in middle-to-old-aged American adults using the updated National Health and Nutrition Examination Survey data.Multivariable-adjusted general linear and weighted quantile sum models were employed to analyze associations of VOC metabolites(VOCMs),representing internal VOCs exposure levels,with OP-related phenotypes.An AOP framework based on network analysis was developed by extracting target genes and phenotypes.Among 3555 American adults aged≥40 years(539 OP participants),we found that increasing urinary 3-and 4-methylhippuric acid,N-acetyl-S-(n-propyl)-l-cysteine(BPMA),and N-acetyl-S-(3-hydroxypropyl)-l-cysteine were associated with elevated OP odds with odds ratios(ORs)(95%confidence intervals,95%CIs)being 1.254(1.016 to 1.548),1.182(1.014 to 1.377),and 1.244(1.029 to 1.505),respectively,per standard deviation.Urinary BPMA and N-acetyl-S-(2-cyanoethyl)-l-cysteine were inversely associated with lumbar spine bone mineral density(BMD),while urinary N-acetyl-S-(2-hydroxypropyl)-l-cysteine was positively associated with hip BMD.Additionally,OP odds increased by 46.0%(95%CI:3.9%to 105.1%)per quartile increment in the VOC mixture.AOP analysis identified 53 target genes and 9 target phenotypes,and 5 of 9 target phenotypes were oxidative stress(OS)-related.Literature and the“AOP 482”framework implied the core role of OS in the VOC exposure and prevalent OP association,with the interleukin-6 as themolecular initiating event.Our findings provided a theoretical basis for further investigation.
基金Projects(52222810,52178383)supported by the National Natural Science Foundation of China。
文摘Axial chain rockbursts(ACRs)repeatedly occur in deep tunnels during drilling and blasting methodology(D&B)within locked-in stress zones,severely hindering construction progress.In extremely cases,ACRs can persist for 7−10 d and affect areas exceeding 20 m along tunnel axis.Through integrated geological investigations and microseismic(MS)monitoring,the geological characteristics,MS activity patterns,and formation mechanisms of ACRs were analyzed.In tectonically active regions,locked-in stress zones arise from interactions between multiple structural planes.Blasting dynamic disturbances during tunnel excavation in these zones trigger early slippage along structural planes and fractures in the surrounding rock,with MS events developing ahead of the working face.High-energy MS events dominate during the development and occurrence stages of ACRs,extending 20−30 m(3−4 tunnel diameters)ahead of the working face.Following the ACRs,low-energy MS events primarily occur behind the working face.Tensile fracturing is the predominant failure mode during ACRs.Shear and mixed fractures primarily occur within the ACRs zone during the intra-ACR phase.Monitoring MS event locations ahead of the working face provides a reliable approach for prewarning potential ACR-prone zones.
基金support from the National Natural Science Foundation of China(Grant Nos.12172332,11727803 and 12072009)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LZ23A020007)the Fundamental Research Funds for the Provincial Universities of Zhejiang(Grant No.RF-C2022003).
文摘The presence of residual stresses in materials or engineering structures can significantly influence their mechanical per-formance.Accurate measurement of residual stresses is of great importance to ensure their in-service reliability.Although numerous instrumented indentation methods have been proposed to evaluate residual stresses,the majority of them require a stress-free reference sample as a comparison benchmark,thereby limiting their applicability in scenarios where obtaining stress-free reference samples is challenging.In this work,through a number of finite element simulations,it was found that the loading exponent of the loading load-depth curve and the recovered depth during unloading are insensitive to residual stresses.The loading curve of the stress-free specimen was virtually reconstructed using such stress-insensitive parameters extracted from the load-depth curves of the stressed state,thus eliminating the requirement for stress-free reference samples.The residual stress was then correlated with the fractional change in loading work between stressed and stress-free loading curves through dimensional analysis and finite element simulations.Based on this correlation,an instrumented sharp indentation method for measuring equibiaxial residual stress without requiring a stress-free specimen was established.Both numerical and experimental verifications were carried out to demonstrate the accuracy and reliability of the newly proposed method.The maximum relative error and absolute error in measured residual stresses are typically within±20%and±20 MPa,respectively.
文摘Hydraulic fracturing plays a critical role in enhancing shale gas production in deep shale reservoirs.Conventional hydraulic fracturing simulation methods rely on prefabricated grids,which can be hindered by the challenge of being computationally overpowered.This study proposes an efficient fracturing simulator to analyze fracture morphology during hydraulic fracturing processes in deep shale gas reservoirs.The simulator integrates the boundary element displacement discontinuity method and the finite volume method to model the fluid-solid coupling process by employing a pseudo-3D fracture model to calculate the fracture height.In particular,the Broyden iteration method was introduced to improve the computational efficiency and model robustness;it achieved a 46.6%reduction in computation time compared to the Newton-Raphson method.The influences of horizontal stress differences,natural fracture density,and natural fracture angle on the modified zone of the reservoir were simulated,and the following results were observed.(1)High stress difference reservoirs have smaller stimulated reservoir area than low stress difference reservoirs.(2)A higher natural fracture angle resulted in larger modification zones at low stress differences,while the effect of a natural fracture angle at high stress differences was not significant.(3)High-density and long natural fracture zones played a significant role in enhancing the stimulated reservoir area.These findings are critical for comprehending the impact of geological parameters on deep shale reservoirs.
基金Projects(52374094,52374218,52174122)supported by the National Natural Science Foundation of ChinaProject(ZR2022YQ49)supported by the Excellent Youth Fund of Shandong Natural Science Foundation,ChinaProjects(tspd20210313,tsqn202211150)supported by the Taishan Scholar Project in Shandong Province,China。
文摘The surrounding rock of the soft rock roadway is seriously deformed and damaged under the superposition of mining stress and fault tectonic stress.In this paper,taking the No.232206 intake roadway in Meihuajing Coal Mine as the engineering background,the deformation and failure law of the surrounding rock of the roadway in different fault protection pillar widths were obtained by numerical simulation method.On this basis,the mechanical model of the roadway under the action of hanging wall overburden migration and fault slip in normal faults was established,and the energy-driven mechanism of large deformation of the surrounding rock of the roadway was revealed.The ratio T of the energy applying on anchoring surrounding rock to the resistant energy of the anchored surrounding rock was defined as the criterion for the deformation of the roadway.Finally,it was calculated according to the actual working conditions on site,and the control method of“stress relief-support reinforcement”was used to support the roadway with the risk of large deformation.The on-site monitoring results show that the control effect of the surrounding rock of the roadway is obvious.
基金supported by the National Natural Science Foundation of China(52174162)the Fundamental Research Funds for the Central Universities(FRF-TP-20-002A3).
文摘Accurate prediction of coal and gas outburst(CGO)hazards is paramount in gas disaster prevention and control.This paper endeavors to overcome the constraints posed by traditional prediction indexes when dealing with CGO incidents under low gas pressure conditions.In pursuit of this objective,we have studied and established a mechanical model of the working face under abnormal stress and the excitation energy conditions of CGO,and proposed a method for predicting the risk of CGO under abnormal stress.On site application verification shows that when a strong outburst hazard level prediction is issued,there is a high possibility of outburst disasters occurring.In one of the three locations where we predicted strong outburst hazards,a small outburst occurred,and the accuracy of the prediction was higher than the traditional drilling cuttings index S and drilling cuttings gas desorption index q.Finally,we discuss the mechanism of CGO under the action of stress anomalies.Based on the analysis of stress distribution changes and energy accumulation characteristics of coal under abnormal stress,this article believes that the increase in outburst risk caused by high stress abnormal gradient is mainly due to two reasons:(1)The high stress abnormal gradient leads to an increase in the plastic zone of the coal seam.After the working face advances,it indirectly leads to an increase in the gas expansion energy that can be released from the coal seam before reaching a new stress equilibrium.(2)Abnormal stress leads to increased peak stress of coal body in front of working face.When coal body in elastic area transforms to plastic area,its failure speed is accelerated,which induces accelerated gas desorption and aggravates the risk of outburst.
文摘Protein aggregates,mitochondrial import stress and neurodegenerative disorders:A salient hallmark of several neurodegenerative diseases,including Parkinson’s disease,is the abundance of protein aggregates(Goiran et al.,2022).This molecular event is believed to lead to activation of stress pathways ultimately resulting in cellular dysfunction(Eldeeb et al.,2022).Accordingly,many lines of research investigations focused on dampening the formation of protein aggregates or augmenting the clearance of protein aggregates as a potential therapeutic strategy to counteract the progression of neurodegenerative diseases,albeit with little success(Costa-Mattioli and Walter,2020).Cell stress cues such as the accumulation of protein aggregates lead to the activation of stress response pathways that aid cells in responding to the damage.Despite the notion that the transient activation of these pathways helps cells cope with stressors,persistent activation can induce unwanted apoptosis of cells and reduce overall tissue strength as well as lead to an accumulation of aggregation-prone proteins(Hetz and Papa,2018).Mutations in proteins involved in stress signaling termination can cause conditions like ataxia and early-onset dementia(Conroy et al.,2014).Therefore,it is crucial for stress response signaling to be turned off once conditions have improved.Nevertheless,the mechanisms by which cells silence these signals are still elusive.
基金Supported in part by Natural Science Foundation of Guangxi(2023GXNSFAA026246)in part by the Central Government's Guide to Local Science and Technology Development Fund(GuikeZY23055044)in part by the National Natural Science Foundation of China(62363003)。
文摘In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.
基金supported by the Rural Revitalization Tea Industry Technical Service Project of Fujian Agriculture and Forestry University(Grant No.11899170145)the“Double firstclass”scientific and technological innovation capacity and enhancement cultivation plan of Fujian Agriculture and Forestry University(Grant No.KSYLP004)+4 种基金6.18 Tea Industry Technology Branch of Collaborative Innovation Institute(Grant No.K1520001A)Fujian Agriculture and Forestry University Construction Project for Technological Innovation and Service System of Tea Industry Chain(Grant No.K1520005A01)Tea Industry Branch of Collaborative Innovation Institute of Fujian Agriculture and Forestry University(Grant No.K1521015A)Science and Technology Innovation Special Fund Project of Fujian Agriculture and Forestry University(Grant No.KFb22020XA)the Special Fund for Science and Technology Innovation of Fujian Zhang Tianfu Tea Development Foundation(Grant No.FJZTF01).
文摘Drought stress is a serious natural challenge for tea plants that significantly affects tea yield and quality.miR171s play critical roles in plant stress responses,however,their role in drought stress tolerance in tea plants(Camellia sinensis)is poorly understood.This study experimentally verified the expression patterns of csn-miR171b-3p_2 and its target,scarecrow-like(SCL).We found that csn-miR171b-3p_2 could target and regulate CsSCL6-4 to play an important role in the defense against drought stress in tea plants.CsSCL6-4 is located in the nucleus and is selfactivated in vivo.In addition,we obtained 819 putative binding regions of CsSCL6-4 using DNA affinity purification sequencing analysis,which were assigned to 786 different genes,four of which were drought-resistant genes(CsPrx,CsSDR,CsFAD7,and CsCER1).Yeast one-hybrid and dual-luciferase reporter assays revealed that CsSCL6-4 directly promoted the expression of these four drought resistance genes by binding motifs 1/2/3 in their promoter regions.Both overexpression and suppression of CsSCL6-4 proved that CsSCL6-4 participated in the defense against drought stress in tea plants by regulating the expression of CsPrx,CsSDR,CsFAD7,and CsCER1.In addition,suppression of csn-miR171b-3p_2 expression significantly increased the expression of CsSCL6-4 and activated CsSCL6-4-bound gene transcription under drought stress.Therefore,the csn-miR171b-3p_2-CsSCL6-4 module participates in tea plant resistance to drought stress by promoting the expression of drought resistance genes.Our results revealed the function of csn-miR171b-3p_2 in tea plants and provided new insights into the mechanism of tea plant resistance to drought stress.
基金supported by the Natural Science Foundation of Shaanxi Province(Key Program),No.2021JZ-60(to HZ)。
文摘The unfolded protein response is a cellular pathway activated to maintain proteostasis and prevent cell death when the endoplasmic reticulum is overwhelmed by unfolded proteins.However,if the unfolded protein response fails to restore endoplasmic reticulum homeostasis,it can trigger proinflammatory and pro-death signals,which are implicated in various malignancies and are currently being investigated for their role in retinal degenerative diseases.This paper reviews the role of the unfolded protein responsein addressing endoplasmic reticulumstress in retinal degenerative diseases.The accumulation of ubiquitylated misfolded proteins can lead to rapid destabilization of the proteome and cellular demise.Targeting endoplasmic reticulum stress to alleviate retinal pathologies involves multiple strategies,including the use of chemical chaperones such as 4-phenylbutyric acid and tauroursodeoxycholic acid,which enhance protein folding and reduce endoplasmic reticulum stress.Small molecule modulators that influence endoplasmic reticulum stress sensors,including those that increase the expression of the endoplasmic reticulum stress regulator X-box binding protein 1,are also potential therapeutic agents.Additionally,inhibitors of the RNAse activity of inositol-requiring transmembrane kinase/endoribonuclease 1,a key endoplasmic reticulum stress sensor,represent another class of drugs that could prevent the formation of toxic aggregates.The activation of nuclear receptors,such as PPAR and FXR,may also help mitigate ER stress.Furthermore,enhancing proteolysis through the induction of autophagy or the inhibition of deubiquitinating enzymes can assist in clearing misfolded proteins.Combination treatments that involve endoplasmicreticulum-stress-targeting drugs and gene therapies are also being explored.Despite these potential therapeutic strategies,significant challenges remain in targeting endoplasmic reticulum stress for the treatment of retinal degeneration,and further research is essential to elucidate the mechanisms underlying human retinal diseases and to develop effective,well-tolerated drugs.The use of existing drugs that target inositol-requiring transmembrane kinase/endoribonuclease 1 and X-box binding protein 1 has been associated with adverse side effects,which have hindered their clinical translation.Moreover,signaling pathways downstream of endoplasmic reticulum stress sensors can contribute to therapy resistance.Addressing these limitations is crucial for developing drugs that can be effectively used in treating retinal dystrophies.In conclusion,while the unfolded protein response is a promising therapeutic target in retinal degenerative diseases,additional research and development efforts are imperative to overcome the current limitations and improve patient outcomes.
基金supported by the National Nature Science Foundation of China(Grant No.31660568)Guangxi Science and Technology major project(Grant No.GuikeAA22068088)+2 种基金start-up funding for introduced talents in Guangxi University,the Guangxi Colleges and Universities Young and Middle-aged Teachers'Basic Scientific Research Ability Improvement Project(Grant No.2024KY0010)Guangxi Graduate Education Innovation Program(Grant No.YCSW2024093)the Guangxi University Student Innovation and Entrepreneurship Training Program Funding Project(Grant Nos.202310593704,202310593714,202410953044S).
文摘N6-methyladenosine(m^(6)A)modification,the most abundant internal modification in messenger RNA(mRNA)and long non-coding RNA(lncRNA),has emerged as a critical epitranscriptomic regulatory mechanism in eukaryotes.While the importance of m^(6)A modification in various biological processes has been recognized,a comprehensive understanding of its diverse roles in plant biology and agricultural applications remains fragmented.This review analyzes recent advances inm^(6)A modification's biological functions in plants.m^(6)A modification plays crucial roles in multiple aspects of plant life,including seed germination,organ development,and reproductive structure formation.Furthermore,m^(6)A has been found to significantly influence plant responses to environmental stresses,including salt,drought,temperature,and heavy metal exposure.We also uncover m^(6)A involvement in important agricultural traits.This review provides insights into the mechanistic understanding of m^(6)A modification in plants and highlights its applications in agricultural improvement,offering a foundation for future research in crop enhancement and stress resistance.
文摘Heavy metal(HM)contamination severely impacts global agricultural production.HMs toxicity effectively damaged the physiological functions such as imbalanced redox homeostasis,altered antioxidant enzyme activity,damage root system architecture,hindered photosynthetic apparatus,cellular toxicity,restricted mineral accumulation,and changed the metabolite production.Using phytohormones may be a successful strategy for enhancing and stimulating plant tolerance to HMs toxicity without affecting the environment.Melatonin(MT),a novel plant growth regulator,and powerful antioxidant molecule,enhances plant resilience to HMs stress by enhancing seedling growth,protecting the photosynthetic system,increasing nutritional status,balanced redox homeostasis,and restricting HMs accumulation from root to shoot.In addition,MT enhances the activity of antioxidant enzymes and triggers the ascorbate-glutathione(AsA-GSH)cycle,which helps remove excessive ROS.MT improves RuBisCO activity to improve photosynthesis and reduce the breakdown of chlorophyll.To identify future research needs,it is crucial to understand the comprehensive and intricate regulatory mechanisms of exogenous and endogenous MT-mediated reduction of heavy metal toxicity in plants.Melatonin has several functions,and this review sheds light on those functions and the molecular processes by which it alleviates HMs toxicity.More research is needed to fully understand how melatonin affects plant tolerance to heavy metals stress.
