Using molecular dynamics modeling,the change in the shape and density of the macromolecular corona consisting of two oppositely charged polyelectrolytes,including those combined into one block copolymer,on the surface...Using molecular dynamics modeling,the change in the shape and density of the macromolecular corona consisting of two oppositely charged polyelectrolytes,including those combined into one block copolymer,on the surface of a polarized spherical metal nanoparticle was studied.A mathematical model of the structure of the block copolymer chain adsorbed on a polarized spherical nanoparticle is presented for the cases of polyelectrolyte blocks of large and small length.Based on the modeling results,radial and angular distributions of the density of atoms of polyelectrolyte polypeptides adsorbed on the surface of a spherical nanoparticle were calculated depending on its dipole moment.As the dipole moment of the nanoparticle increased,the dense macromolecular shell was destroyed,forming caps of polyelectrolyte macro molecules or fragments of block copolymer of different types on the poles of the polarized nanoparticle.In this case,the macromolecular corona in the region of the poles of the polarized nanoparticle swelled the more strongly,the greater the distance between the charged links in the polymer.展开更多
To regulate the sodium chloride content in Jinhua ham,the impact of NaCl on the activity and conformation of cathepsin B was investigated using spectroscopy and computational methods.The results showed that the activi...To regulate the sodium chloride content in Jinhua ham,the impact of NaCl on the activity and conformation of cathepsin B was investigated using spectroscopy and computational methods.The results showed that the activity of cathepsin B decreased with an increase in Na^(+)cation content and temperature.Additionally,decreasedα-helix content and increasedβ-sheet content were observed.The increase in sulfhydryl group content was attributed to the breaking of original disulfide bonds in the molecular structure or the release of embedded groups.Furthermore,the surface hydrophobicity gradually declined,which was consistent with the analysis of endogenous fluorescence spectroscopy.At the molecular level,the number of hydrogen bonds formed in NaCl-treated samples decreased,and the interactions between the hydrogen bonding were less powerful,which caused instability in the binding of the protein and substrate.The conformation of cathepsin B accurately characterized its activity,and the structural changes had a macroscopic effect on the decrease in protease activity.展开更多
Tajikistan contains the majority of Central Asia’s glaciers,which cover about 6.00%of the national territory;their rapid shrinkage poses a significant threat to regional water resource security.However,glacier monito...Tajikistan contains the majority of Central Asia’s glaciers,which cover about 6.00%of the national territory;their rapid shrinkage poses a significant threat to regional water resource security.However,glacier monitoring in Tajikistan was interrupted after 1991,creating a substantial gap in understanding the current state and temporal evolution of these glaciers.Based on glacier inventory data,in situ measurements,and published literature,this study examined the present status and recent variations of glaciers in Tajikistan through data integration and validation,literature collation and comparative analysis,and the application of Geographic Information System(GIS)spatial analysis techniques.As of 2023,Tajikistan possesses a total of 11,528 glaciers,encompassing an area of 7624.48(±305.58)km2.Small glaciers dominate in number,whereas large glaciers account for the majority of the total area.Over the past two decades,the glacier count has decreased by 2014,and the total area has decreased by 628.98 km2,corresponding to an average annual reduction rate of 0.33%.Regional shrinkage rates range from 4.10%to 22.28%.Glaciers have undergone accelerated mass loss during the past 20 a;only those on the northeastern Pamir Plateau exhibit a weak positive mass balance.Observations of typical monitored glaciers also reveal intensified melting and retreat,consistent with regional trends.In light of the recent acceleration of glacier shrinkage in Tajikistan,focused measures should be implemented to strengthen glacier monitoring,enhance public awareness of glacier preservation,and promote the sustainable development and utilization of glacier tourism.These findings bridge the knowledge gap regarding the spatiotemporal dynamics of Tajikistan’s glaciers over recent decades and provide essential data support for regional water resource management.展开更多
Starting from the foundational static traits underlying the growth and development of flue-cured tobacco, this research conducts a systematic examination of the phenomena and theoretical principles associated with env...Starting from the foundational static traits underlying the growth and development of flue-cured tobacco, this research conducts a systematic examination of the phenomena and theoretical principles associated with environment-driven adaptive changes during its cultivation. It was found that environmental variables-including temperature, light, and moisture-elicit directional shifts in static traits ( e.g. , chemical composition, morphological architecture, and leaf tissue structure) toward enhanced environmental adaptation, characterized by graduality, juvenility, similarity, and correlativity. Upon alterations in ambient conditions, flue-cured tobacco modulates its static traits through integrated physical, chemical, and biological-genetic mechanisms, aiming to optimize resource utilization, mitigate environmental constraints, and preserve internal homeostasis alongside metabolic balance. The investigation further reveals that the adaptive scope of flue-cured tobacco to field environments is malleable and can be extended and elevated via adaptive conditioning commencing at the juvenile stage. In addition, the adaptive alignment between static traits and environmental parameters exerts a substantial impact on the plant s growth dynamics, yield performance, and quality attributes. Beyond its relevance to flue-cured tobacco, the proposed theory offers a meaningful framework for elucidating the pervasive adaptive strategies employed by plants and broader biological systems in response to environmental contingencies.展开更多
Knee osteoarthritis(KOA)is a chronic degenerative disease.Monosodium iodoac-etate(MIA)induction is the most commonly used therapeutic effect evaluation and mechanism of action research model;we observed a lack of stan...Knee osteoarthritis(KOA)is a chronic degenerative disease.Monosodium iodoac-etate(MIA)induction is the most commonly used therapeutic effect evaluation and mechanism of action research model;we observed a lack of standardization and uni-formity in current model building methods,which led us to conduct this study.Background:The aim was to investigate the time-and dose-related changes in the behavioral and pathological characteristics in the MIA-induced KOA model rat.Methods:MIA(40,50,and 60 mg/mL)was injected into the left joint of male Sprague-Dawley rats.After 2 weeks,the changes in the KOA rat model were observed by be-havioral evaluation,imaging-level evaluation,and histological-level evaluation.The changes were also compared after 40-mg/mL MIA injection for 2 and 6 weeks.Results:MIA-induced bone surface defects,osteophyte hyperplasia around the artic-ular rim,increased subchondral bone density,thinning of the sparse trabecular bone,structural disorder,and local clustering were observed.The degree of injury gradually increased with the increase in MIA concentration.After 6 weeks,subchondral bone density and sparse trabecular bone increased in the KOA model.Conclusions:The severity of the model also increased significantly with the changes in dose and time.In dose-dependent experiments,this study revealed that 40 mg/mL was the optimal dose to induce significant pathological changes without causing undue discomfort or death in animals.This dose may induce pathological changes stably and is suitable for long-term observation.展开更多
Lin Wei is a hiking enthusiast.At six o'clock on the last Saturday morning,the temperature at the foot of the mountain was only 2℃,so she put on her thickest fleece jacket.However,after only half an hour of climb...Lin Wei is a hiking enthusiast.At six o'clock on the last Saturday morning,the temperature at the foot of the mountain was only 2℃,so she put on her thickest fleece jacket.However,after only half an hour of climbing,the heat left her drenched in sweat,making her feel very cold.By midday,the temperature was approaching 20℃,and her heavy jacket had to be tied around her waist,becoming a burden during her hike.This outdoor adventure allowed her to appreciate the beautiful scenery,but also subjected her to repeated changes in temperature.展开更多
In recent years,against the backdrop of profound geopolitical changes,the European Union(EU)has been deeply mired in an industrial predicament,showing signs of shrinking production,capital outflows,relocation of produ...In recent years,against the backdrop of profound geopolitical changes,the European Union(EU)has been deeply mired in an industrial predicament,showing signs of shrinking production,capital outflows,relocation of production capacity,and lagging development in future industries.The primary causes of this situation include the energy supply crisis stemming from the decoupling from Russian energy,the impact of America's unilateral trade policy,structural flaws within the EU itself,and the intensification of global industrial competition.To overcome these challenges,the EU has introduced a series of new industrial policies,aiming at revitalizing its industries by strengthening support for local manufacturing,enhancing protective mechanisms for its domestic production,building diversified supply chains,and prioritizing the development of military industry.However,due to multiple obstacles such as heavy external dependence,significant funding gaps,internal divisions,and strategic short-sightedness,the EU still faces a long and arduous journey in its industrial revival.展开更多
BACKGROUND Lumbar interbody fusion(LIF)is the primary treatment for lumbar degenerative diseases.Elderly patients are prone to anxiety and depression after undergoing surgery,which affects their postoperative recovery...BACKGROUND Lumbar interbody fusion(LIF)is the primary treatment for lumbar degenerative diseases.Elderly patients are prone to anxiety and depression after undergoing surgery,which affects their postoperative recovery speed and quality of life.Effective prevention of anxiety and depression in elderly patients has become an urgent problem.AIM To investigate the trajectory of anxiety and depression levels in elderly patients after LIF,and the influencing factors.METHODS Random sampling was used to select 239 elderly patients who underwent LIF from January 2020 to December 2024 in Shenzhen Pingle Orthopedic Hospital.General information and surgery-related indices were recorded,and participants completed measures of psychological status,lumbar spine dysfunction,and quality of life.A latent class growth model was used to analyze the post-LIF trajectory of anxiety and depression levels,and unordered multi-categorical logistic regression was used to analyze the influencing factors.RESULTS Three trajectories of change in anxiety level were identified:Increasing anxiety(n=26,10.88%),decreasing anxiety(n=27,11.30%),and stable anxiety(n=186,77.82%).Likewise,three trajectories of change in depression level were identified:Increasing depression(n=30,12.55%),decreasing depression(n=26,10.88%),and stable depression(n=183,76.57%).Regression analysis showed that having no partner,female sex,elevated Oswestry dysfunction index(ODI)scores,and reduced 36-Item Short Form Health Survey scores all contributed to increased anxiety levels,whereas female sex,postoperative opioid use,and elevated ODI scores all contributed to increased depression levels.CONCLUSION During clinical observation,combining factors to predict anxiety and depression in post-LIF elderly patients enables timely intervention,quickens recovery,and enhances quality of life.展开更多
This study investigates climate-and human-induced hydrological changes in the Zavkhan River-Khyargas Lake Basin,a highly sensitive arid and semi-arid region of Central Asia.Using Mann-Kendall,innovative trend analysis...This study investigates climate-and human-induced hydrological changes in the Zavkhan River-Khyargas Lake Basin,a highly sensitive arid and semi-arid region of Central Asia.Using Mann-Kendall,innovative trend analysis,and Sen's slope estimation methods,historical climate trends(1980-2100)were analyzed,while land cover changes represented human impacts.Future projections were simulated using the MIROC model with Shared Socioeconomic Pathways(SSPs)and the Tank model.Results show that during the past 40 years,air temperature significantly increased(Z=3.93^(***)),while precipitation(Z=-1.54^(*))and river flow(Z=-1.73^(*))both declined.The Khyargas Lake water level dropped markedly(Z=-5.57***).Land cover analysis reveals expanded cropland and impervious areas due to human activity.Under the SSP1.26 scenario,which assumes minimal climate change,air temperature is projected to rise by 2.0℃,precipitation by 21.8 mm,and river discharge by 1.61 m^(3)/s between 2000 and 2100.These findings indicate that both global warming and intensified land use have substantially altered hydrological and climatic processes in the basin,highlighting the vulnerability of western Mongolia's water resources to combined climatic and anthropogenic influence.展开更多
Glacier landslide cascading hazards pose threats to communities and infrastructure,affected by complex processes including the amplification of mass flow volume through erosion and entrainment,transformation of hazard...Glacier landslide cascading hazards pose threats to communities and infrastructure,affected by complex processes including the amplification of mass flow volume through erosion and entrainment,transformation of hazard types,ice-water phase change,and enhanced mobility of the mass flow.Scientifically simulating these physical phenomena proves challenging.This study introduces GMFA(glacier mass flow analysis),an integrated numerical model that advances the field by:(1)proposing depth-averaged fluctuation energy and internal energy equations,(2)incorporating the ice-water phase change and the entrainment-deposition process,and(3)capturing their effects on mass flow runout characteristics.The model employs the finite volume method to solve the multi-physics coupled governing equations,enabling efficient large-scale simulations.The model is verified through three numerical tests covering flow dynamics,temperature evolution,and thermo-hydro-mechanical runout processes.The model is applied to analyze a hazard chain that occurred on 10 September 2020 on the Tibetan Plateau.The multi-scenario simulation results indicate an entrained mass volume of(4.95±0.11)×10^(5)m^(3),and a ratio of entrained mass volume to source material volume of 0.44.The solid concentration decreases from 0.6-0.7 to 0.1-0.15 with increasing runout distance,indicating a transition from avalanche to debris flood.The internal energy rises by(3-4)×10^(3)kJ/m^(3),driving rapid ice melting from 0.1 to 0.2 to near-zero concentration.The model effectively quantifies volume amplification,ice-water phase changes,and multi-hazard transformations.This model pushes the geoscience frontier,extending computational capability from single-to multi-hazard simulations and providing a powerful tool for analyzing glacier cascading hazards.展开更多
DNA takes on multi-different conformations such as A-, B-, C-, D- and Z-form. These conformations can transit to one another when DNA deposited in some metal ions solutions or when changing the concentrations of the s...DNA takes on multi-different conformations such as A-, B-, C-, D- and Z-form. These conformations can transit to one another when DNA deposited in some metal ions solutions or when changing the concentrations of the same metal ions. Here, several major conformational transitions of DNA induced by metal ions under different environment were introduced and the mechanism of the interaction of metal ions with DNA was discuss in detail.展开更多
The structure and function of protein are strongly pH-dependence.However,the inonization state of the protein varied with the pH value also depends on the local structure and environment of protein.It is not same as t...The structure and function of protein are strongly pH-dependence.However,the inonization state of the protein varied with the pH value also depends on the local structure and environment of protein.It is not same as those of free residues in solution.To get more detail information from the structural change,molecular simulation is widely used.Bovine serum albumin(BSA)is the most abundant protein and commonly used auxiliary drug in the biochemical experiments.It is the natural protein with single free cysteine.We used BSA as model protein to investigate the pH induced local environmental and conformational changes with molecular simulation and fluorescent methodology.展开更多
A molecular dynamics (MD) simulation is performed on a DNA photolyase to study the conformational behavior of the photoactive cofactor flavin adenine dinucleotide (FAD) inside the enzyme pocket. A DNA photolyase is a ...A molecular dynamics (MD) simulation is performed on a DNA photolyase to study the conformational behavior of the photoactive cofactor flavin adenine dinucleotide (FAD) inside the enzyme pocket. A DNA photolyase is a highly efficient light-driven enzyme that repairs the UV-induced cyclobutane pyrimidine dimer in damaged DNA. In this work, the FAD conformational and dynamic changes were studied within the total complex structure of a DNA photolyase protein (containing FADH–, MTHF, and DNA molecules) embedded in a water solvent. We aimed to compare the conformational changes of the FAD cofactor and other constituent fragments of the molecular system under consideration. The obtained results were discussed to gain insight into the light-driven mechanism of DNA repair by a DNA photolyase enzyme—based on the enzyme structure, the FAD mobility, and conformation shape.展开更多
Achieving selectivity in cell penetrating peptide(CPP)design is crucial to mitigate systemic toxicity and enable precise targeting based on distinct cellular phenotypes.Herein,we designed an amphiphilic peptide,L17Yp,...Achieving selectivity in cell penetrating peptide(CPP)design is crucial to mitigate systemic toxicity and enable precise targeting based on distinct cellular phenotypes.Herein,we designed an amphiphilic peptide,L17Yp,by incorporating phosphorylated tyrosine into natural occurring M-lycotoxin peptide,known for its potent membrane-lytic activity.This strategic modification induced a conformational shift,as confirmed by circular dichroism spectroscopy,transitioning it from its bioactiveα-helix conformation to an inactive random coli configuration,effectively shielding its membrane-penetrating capacity.Upon exposure to alkaline phosphatase,L17Yp undergoes enzymatic dephosphorylation,prompting a conformational shift that restores its membrane-transduction capabilities.This unique property hold promises for selective drug delivery.This work introduces an enzymatic approach for targeted perturbation of the cell membrane,offering promising prospects for precise drug delivery applications.展开更多
Current resolved structures of GPCRs and G protein complexes provided important insights into G protein activation. However, the binding or dissociation of GPCRs with G protein is instantaneous and highly dynamic in t...Current resolved structures of GPCRs and G protein complexes provided important insights into G protein activation. However, the binding or dissociation of GPCRs with G protein is instantaneous and highly dynamic in the intracellular environment. The conformational dynamic of G protein still needs to be addressed. In this study, we applied ^(19)F solution NMR spectroscopy to monitor the conformational changes of G protein upon interact with detergent mimicking membrane and receptor. Our results show that there are two states equilibria in the G_(α)in apo states. The interaction of G_(α)with detergents will accelerate this conformational transformation and induce a state that tends to bind to GPCRs. Finally, the G_(α)proteins presented a fully activation state when they coupled to GPCRs.展开更多
The toxicity of PM_(2.5)does not necessarily change synchronously with its mass concentration.In this study,the chemical composition(carbonaceous species,water-soluble ions,and metals)and oxidative potential(dithiothr...The toxicity of PM_(2.5)does not necessarily change synchronously with its mass concentration.In this study,the chemical composition(carbonaceous species,water-soluble ions,and metals)and oxidative potential(dithiothreitol assay,DTT)of PM_(2.5)were investigated in 2017/2018 and 2022 in Xiamen,China.The decrease rate of volume-normalized DTT(DTTv)(38%)was lower than that of PM_(2.5)(55%)between the two sampling periods.However,the mass-normalized DTT(DTTm)increased by 44%.Clear seasonal patterns with higher levels in winter were found for PM_(2.5),most chemical constituents and DTTv but not for DTTm.The large decrease in DTT activity(84%−92%)after the addition of EDTA suggested that watersoluble metals were the main contributors to DTT in Xiamen.The increased gap between the reconstructed and measured DTTv and the stronger correlations between the reconstructed/measured DTT ratio and carbonaceous species in 2022were observed.The decrease rates of the hazard index(32.5%)and lifetime cancer risk(9.1%)differed from those of PM_(2.5)and DTTv due to their different main contributors.The PMF-MLR model showed that the contributions(nmol/(min·m^(3)))of vehicle emission,coal+biomass burning,ship emission and secondary aerosol to DTTv in 2022 decreased by 63.0%,65.2%,66.5%,and 22.2%,respectively,compared to those in 2017/2018,which was consistent with the emission reduction of vehicle exhaust and coal consumption,the adoption of low-sulfur fuel oil used on board ships and the reduced production of WSOC.However,the contributions of dust+sea salt and industrial emission increased.展开更多
A low temperature (LoTemp?) polymerase chain reaction (PCR), conducted at cycling temperatures not to exceed 85℃and catalyzed by a novel highly processive HiFi? DNA polymerase with proofreading function, was used to ...A low temperature (LoTemp?) polymerase chain reaction (PCR), conducted at cycling temperatures not to exceed 85℃and catalyzed by a novel highly processive HiFi? DNA polymerase with proofreading function, was used to study the topological conformational changes of the human papillomavirus (HPV) L1 gene DNA fragments bound to the insoluble amorphous aluminum hydroxyphosphate sulfate (AAHS) adjuvant in the quadrivalent HPV vaccine, Gardasil?. L1 gene DNA fragments of HPV-11, HPV-18 and HPV-16 were detected in the AAHS particles by nested PCR, but all were lacking a region that was amplifiable by an MY09 degenerate primer. In addition, a pair of degenerate consensus GP6/MY11 primers was able to amplify a target segment of the HPV-11 L1 gene DNA and the HPV-18 L1 gene DNA bound to the AAHS particles as expected for any HPV DNA in the B-conformation. However, there was no co-amplification of the HPV-16 L1 gene DNA known to coexist in the same samples. The lack of co-amplification was verified by direct DNA sequencing of the PCR amplicons. The companion HPV-16 L1 gene DNA in the same sample required repeated PCRs with a pair of modified non-degenerate GP6/ MY11 primers for detection. This melting profile of the HPV-16 L1 gene DNA was similar to that of the HPV-16 L1 gene DNA recently discovered in the postmortem blood of a young woman who suffered a sudden unexpected death 6 months after Gardasil? vaccination. The findings suggest that the topological conformational changes in the HPV L1 gene DNA residues bound to the AAHS adjuvant may be genotype-related. The special non-B-conformation may prevent the HPV-16 L1 gene DNA from being degraded in the body of the vaccine recipients after in- tramuscular injection.展开更多
Introduction Integrins are a large family of adhesion molecules broadly expressed on the surface of a wide variety of cells as heterodimers. Binding of integrins to ligands provides not only mechanical anchorage for t...Introduction Integrins are a large family of adhesion molecules broadly expressed on the surface of a wide variety of cells as heterodimers. Binding of integrins to ligands provides not only mechanical anchorage for the cell to another cell or展开更多
Terrestrial ecosystems heavily depend on vegetation,which responds to carbon dioxide(CO_(2))fertilization in hot and humid regions.The subtropical humid karst region is a hot and humid region;whether and to what exten...Terrestrial ecosystems heavily depend on vegetation,which responds to carbon dioxide(CO_(2))fertilization in hot and humid regions.The subtropical humid karst region is a hot and humid region;whether and to what extent CO_(2)fertilization affects vegetation changes in such regions remains unclear.In this study,we investigated the degree to which CO_(2)fertilization influences vegetation changes,along with their spatial and temporal differences,in the subtropical humid karst region using time-lag effect analysis,a random forest model,and multiple regression analysis.Results showed that CO_(2)fertilization plays an important role in vegetation changes,exhibiting clear spatial variations across different geomorphological zones,with its degree of influence ranging mainly between 11%and 25%.The highest contribution of CO_(2)fertilization was observed in the karst basin and non-karstic region,whereas the lowest contribution was found in the karst plateau region.Previous studies have primarily attributed vegetation changes in subtropical humid karst region to ecological engineering,leading to an overestimation of its contribution to these changes.The findings of this study enhance the understanding of the mechanism of vegetation changes in humid karst region and provide theoretical and practical insights for ecological and environmental protection in these regions.展开更多
BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic im...BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic implications and longterm management strategies.Vascular and metabolic factors are being thought to play a role in such autoimmune neuro-inflammatory disorders,apart from the obvious immune mediated damage.With the advent of optical coherence tomography angiography(OCTA),it is easy to pick up on these subclinical macular microvascular and structural changes.AIM To study the macular microvascular and structural changes on OCTA in atypical optic neuritis.METHODS This observational cross-sectional study involved 8 NMOSD and 17 MOGAD patients,diagnosed serologically,as well as 10 healthy controls.Macular vascular density(MVD)and ganglion cell+inner plexiform layer thickness(GCIPL)were studied using OCTA.RESULTS There was a significant reduction in MVD in NMOSD and MOGAD affected as well as unaffected eyes when compared with healthy controls.NMOSD and MOGAD affected eyes had significant GCIPL thinning compared with healthy controls.NMOSD unaffected eyes did not show significant GCIPL thinning compared to healthy controls in contrast to MOGAD unaffected eyes.On comparing NMOSD with MOGAD,there was no significant difference in terms of MVD or GCIPL in the affected or unaffected eyes.CONCLUSION Although significant microvascular and structural changes are present on OCTA between atypical optic neuritis and normal patients,they could not help in differentiating between NMOSD and MOGAD cases.展开更多
基金the financial support of the Ministry of Science and Higher Education of the Russian Federation within the framework of a grant for conducting large scientific projects in priority areas of scientific and technological development 075-15-2024-550。
文摘Using molecular dynamics modeling,the change in the shape and density of the macromolecular corona consisting of two oppositely charged polyelectrolytes,including those combined into one block copolymer,on the surface of a polarized spherical metal nanoparticle was studied.A mathematical model of the structure of the block copolymer chain adsorbed on a polarized spherical nanoparticle is presented for the cases of polyelectrolyte blocks of large and small length.Based on the modeling results,radial and angular distributions of the density of atoms of polyelectrolyte polypeptides adsorbed on the surface of a spherical nanoparticle were calculated depending on its dipole moment.As the dipole moment of the nanoparticle increased,the dense macromolecular shell was destroyed,forming caps of polyelectrolyte macro molecules or fragments of block copolymer of different types on the poles of the polarized nanoparticle.In this case,the macromolecular corona in the region of the poles of the polarized nanoparticle swelled the more strongly,the greater the distance between the charged links in the polymer.
基金supported by the National Natural Science Foundation of China(31972097)Jiangsu Key Research and Development Plan(Modern Agriculture)(BE2020302)+1 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(24KJB550003)2024 Huaiyin Institute of Technology Talent Recruitment Research Startup Fund Project(Z301B24521)。
文摘To regulate the sodium chloride content in Jinhua ham,the impact of NaCl on the activity and conformation of cathepsin B was investigated using spectroscopy and computational methods.The results showed that the activity of cathepsin B decreased with an increase in Na^(+)cation content and temperature.Additionally,decreasedα-helix content and increasedβ-sheet content were observed.The increase in sulfhydryl group content was attributed to the breaking of original disulfide bonds in the molecular structure or the release of embedded groups.Furthermore,the surface hydrophobicity gradually declined,which was consistent with the analysis of endogenous fluorescence spectroscopy.At the molecular level,the number of hydrogen bonds formed in NaCl-treated samples decreased,and the interactions between the hydrogen bonding were less powerful,which caused instability in the binding of the protein and substrate.The conformation of cathepsin B accurately characterized its activity,and the structural changes had a macroscopic effect on the decrease in protease activity.
基金supported by the National Key R&D Plan“Inter-governmental International Science&Technology Innovation Cooperation”Key Specialized Program,China(2025YFE0102800)the Program of the State Key Laboratory of Cryospheric Science and Frozen Soil Engineering,Chinese Academy of Sciences(CSFSE-ZZ-2403).
文摘Tajikistan contains the majority of Central Asia’s glaciers,which cover about 6.00%of the national territory;their rapid shrinkage poses a significant threat to regional water resource security.However,glacier monitoring in Tajikistan was interrupted after 1991,creating a substantial gap in understanding the current state and temporal evolution of these glaciers.Based on glacier inventory data,in situ measurements,and published literature,this study examined the present status and recent variations of glaciers in Tajikistan through data integration and validation,literature collation and comparative analysis,and the application of Geographic Information System(GIS)spatial analysis techniques.As of 2023,Tajikistan possesses a total of 11,528 glaciers,encompassing an area of 7624.48(±305.58)km2.Small glaciers dominate in number,whereas large glaciers account for the majority of the total area.Over the past two decades,the glacier count has decreased by 2014,and the total area has decreased by 628.98 km2,corresponding to an average annual reduction rate of 0.33%.Regional shrinkage rates range from 4.10%to 22.28%.Glaciers have undergone accelerated mass loss during the past 20 a;only those on the northeastern Pamir Plateau exhibit a weak positive mass balance.Observations of typical monitored glaciers also reveal intensified melting and retreat,consistent with regional trends.In light of the recent acceleration of glacier shrinkage in Tajikistan,focused measures should be implemented to strengthen glacier monitoring,enhance public awareness of glacier preservation,and promote the sustainable development and utilization of glacier tourism.These findings bridge the knowledge gap regarding the spatiotemporal dynamics of Tajikistan’s glaciers over recent decades and provide essential data support for regional water resource management.
基金Supported by Changsha Tobacco Company Science and Technology Project(2020-2024A04).
文摘Starting from the foundational static traits underlying the growth and development of flue-cured tobacco, this research conducts a systematic examination of the phenomena and theoretical principles associated with environment-driven adaptive changes during its cultivation. It was found that environmental variables-including temperature, light, and moisture-elicit directional shifts in static traits ( e.g. , chemical composition, morphological architecture, and leaf tissue structure) toward enhanced environmental adaptation, characterized by graduality, juvenility, similarity, and correlativity. Upon alterations in ambient conditions, flue-cured tobacco modulates its static traits through integrated physical, chemical, and biological-genetic mechanisms, aiming to optimize resource utilization, mitigate environmental constraints, and preserve internal homeostasis alongside metabolic balance. The investigation further reveals that the adaptive scope of flue-cured tobacco to field environments is malleable and can be extended and elevated via adaptive conditioning commencing at the juvenile stage. In addition, the adaptive alignment between static traits and environmental parameters exerts a substantial impact on the plant s growth dynamics, yield performance, and quality attributes. Beyond its relevance to flue-cured tobacco, the proposed theory offers a meaningful framework for elucidating the pervasive adaptive strategies employed by plants and broader biological systems in response to environmental contingencies.
基金Construction Project of High-Level Traditional Chinese Medicine Key Discipline of National Administration of Traditional Chinese Medicine,Grant/Award Number:zyyzdxk-2023022Key Team of Scientific and Technological Innovation Talents of Shanxi Province with Integrated Traditional Chinese and Western Medicine for Preventing and Treating Rheumatological Diseases,Grant/Award Number:202204051002033+4 种基金Traditional Chinese Medicine+Stem Cell Innovation Project,Grant/Award Number:2024KJZY0062023 Shanxi Graduate Research Practice Project,Grant/Award Number:2023KY6762023 Graduate Innovation and Entrepreneurship Project of Shanxi University of Traditional Chinese Medicine,Grant/Award Number:2023CX023 and 2023CX027Science and Technology Innovation Project for University in Shanxi Province,Grant/Award Number:2022L358Key Laboratory of Rheumatological and Immunological Diseases Treated by Integrated Chinese and Western Medicine,Grant/Award Number:zyyyjs2024021。
文摘Knee osteoarthritis(KOA)is a chronic degenerative disease.Monosodium iodoac-etate(MIA)induction is the most commonly used therapeutic effect evaluation and mechanism of action research model;we observed a lack of standardization and uni-formity in current model building methods,which led us to conduct this study.Background:The aim was to investigate the time-and dose-related changes in the behavioral and pathological characteristics in the MIA-induced KOA model rat.Methods:MIA(40,50,and 60 mg/mL)was injected into the left joint of male Sprague-Dawley rats.After 2 weeks,the changes in the KOA rat model were observed by be-havioral evaluation,imaging-level evaluation,and histological-level evaluation.The changes were also compared after 40-mg/mL MIA injection for 2 and 6 weeks.Results:MIA-induced bone surface defects,osteophyte hyperplasia around the artic-ular rim,increased subchondral bone density,thinning of the sparse trabecular bone,structural disorder,and local clustering were observed.The degree of injury gradually increased with the increase in MIA concentration.After 6 weeks,subchondral bone density and sparse trabecular bone increased in the KOA model.Conclusions:The severity of the model also increased significantly with the changes in dose and time.In dose-dependent experiments,this study revealed that 40 mg/mL was the optimal dose to induce significant pathological changes without causing undue discomfort or death in animals.This dose may induce pathological changes stably and is suitable for long-term observation.
文摘Lin Wei is a hiking enthusiast.At six o'clock on the last Saturday morning,the temperature at the foot of the mountain was only 2℃,so she put on her thickest fleece jacket.However,after only half an hour of climbing,the heat left her drenched in sweat,making her feel very cold.By midday,the temperature was approaching 20℃,and her heavy jacket had to be tied around her waist,becoming a burden during her hike.This outdoor adventure allowed her to appreciate the beautiful scenery,but also subjected her to repeated changes in temperature.
文摘In recent years,against the backdrop of profound geopolitical changes,the European Union(EU)has been deeply mired in an industrial predicament,showing signs of shrinking production,capital outflows,relocation of production capacity,and lagging development in future industries.The primary causes of this situation include the energy supply crisis stemming from the decoupling from Russian energy,the impact of America's unilateral trade policy,structural flaws within the EU itself,and the intensification of global industrial competition.To overcome these challenges,the EU has introduced a series of new industrial policies,aiming at revitalizing its industries by strengthening support for local manufacturing,enhancing protective mechanisms for its domestic production,building diversified supply chains,and prioritizing the development of military industry.However,due to multiple obstacles such as heavy external dependence,significant funding gaps,internal divisions,and strategic short-sightedness,the EU still faces a long and arduous journey in its industrial revival.
基金Supported by the Scientific Research Projects of the Health System in Pingshan District,No.2023122.
文摘BACKGROUND Lumbar interbody fusion(LIF)is the primary treatment for lumbar degenerative diseases.Elderly patients are prone to anxiety and depression after undergoing surgery,which affects their postoperative recovery speed and quality of life.Effective prevention of anxiety and depression in elderly patients has become an urgent problem.AIM To investigate the trajectory of anxiety and depression levels in elderly patients after LIF,and the influencing factors.METHODS Random sampling was used to select 239 elderly patients who underwent LIF from January 2020 to December 2024 in Shenzhen Pingle Orthopedic Hospital.General information and surgery-related indices were recorded,and participants completed measures of psychological status,lumbar spine dysfunction,and quality of life.A latent class growth model was used to analyze the post-LIF trajectory of anxiety and depression levels,and unordered multi-categorical logistic regression was used to analyze the influencing factors.RESULTS Three trajectories of change in anxiety level were identified:Increasing anxiety(n=26,10.88%),decreasing anxiety(n=27,11.30%),and stable anxiety(n=186,77.82%).Likewise,three trajectories of change in depression level were identified:Increasing depression(n=30,12.55%),decreasing depression(n=26,10.88%),and stable depression(n=183,76.57%).Regression analysis showed that having no partner,female sex,elevated Oswestry dysfunction index(ODI)scores,and reduced 36-Item Short Form Health Survey scores all contributed to increased anxiety levels,whereas female sex,postoperative opioid use,and elevated ODI scores all contributed to increased depression levels.CONCLUSION During clinical observation,combining factors to predict anxiety and depression in post-LIF elderly patients enables timely intervention,quickens recovery,and enhances quality of life.
基金The National University of Mongolia,No.P2024-4814The Mongolian Science and Technology Foundation,No.CHN-2022/274The‘Chey Institute for Advanced Studies’International Scholar Exchange Fellowship for the Academic Year of 2025-2026。
文摘This study investigates climate-and human-induced hydrological changes in the Zavkhan River-Khyargas Lake Basin,a highly sensitive arid and semi-arid region of Central Asia.Using Mann-Kendall,innovative trend analysis,and Sen's slope estimation methods,historical climate trends(1980-2100)were analyzed,while land cover changes represented human impacts.Future projections were simulated using the MIROC model with Shared Socioeconomic Pathways(SSPs)and the Tank model.Results show that during the past 40 years,air temperature significantly increased(Z=3.93^(***)),while precipitation(Z=-1.54^(*))and river flow(Z=-1.73^(*))both declined.The Khyargas Lake water level dropped markedly(Z=-5.57***).Land cover analysis reveals expanded cropland and impervious areas due to human activity.Under the SSP1.26 scenario,which assumes minimal climate change,air temperature is projected to rise by 2.0℃,precipitation by 21.8 mm,and river discharge by 1.61 m^(3)/s between 2000 and 2100.These findings indicate that both global warming and intensified land use have substantially altered hydrological and climatic processes in the basin,highlighting the vulnerability of western Mongolia's water resources to combined climatic and anthropogenic influence.
基金supports from the National Natural Science Foundation of China(Grant No.U20A20112)the Research Grants Council of the Hong Kong SAR Government,China(Grant Nos.T22-606/23-R and 16206923).
文摘Glacier landslide cascading hazards pose threats to communities and infrastructure,affected by complex processes including the amplification of mass flow volume through erosion and entrainment,transformation of hazard types,ice-water phase change,and enhanced mobility of the mass flow.Scientifically simulating these physical phenomena proves challenging.This study introduces GMFA(glacier mass flow analysis),an integrated numerical model that advances the field by:(1)proposing depth-averaged fluctuation energy and internal energy equations,(2)incorporating the ice-water phase change and the entrainment-deposition process,and(3)capturing their effects on mass flow runout characteristics.The model employs the finite volume method to solve the multi-physics coupled governing equations,enabling efficient large-scale simulations.The model is verified through three numerical tests covering flow dynamics,temperature evolution,and thermo-hydro-mechanical runout processes.The model is applied to analyze a hazard chain that occurred on 10 September 2020 on the Tibetan Plateau.The multi-scenario simulation results indicate an entrained mass volume of(4.95±0.11)×10^(5)m^(3),and a ratio of entrained mass volume to source material volume of 0.44.The solid concentration decreases from 0.6-0.7 to 0.1-0.15 with increasing runout distance,indicating a transition from avalanche to debris flood.The internal energy rises by(3-4)×10^(3)kJ/m^(3),driving rapid ice melting from 0.1 to 0.2 to near-zero concentration.The model effectively quantifies volume amplification,ice-water phase changes,and multi-hazard transformations.This model pushes the geoscience frontier,extending computational capability from single-to multi-hazard simulations and providing a powerful tool for analyzing glacier cascading hazards.
基金This work was supported by Guangdong Provincial Natural Science Foundation of China(No.021093)Guangdong Keystone Science and Technology Foundation(No.2KM04502S)Guangdong Universities Natural Science Research Foundation(No.200018).
文摘DNA takes on multi-different conformations such as A-, B-, C-, D- and Z-form. These conformations can transit to one another when DNA deposited in some metal ions solutions or when changing the concentrations of the same metal ions. Here, several major conformational transitions of DNA induced by metal ions under different environment were introduced and the mechanism of the interaction of metal ions with DNA was discuss in detail.
文摘The structure and function of protein are strongly pH-dependence.However,the inonization state of the protein varied with the pH value also depends on the local structure and environment of protein.It is not same as those of free residues in solution.To get more detail information from the structural change,molecular simulation is widely used.Bovine serum albumin(BSA)is the most abundant protein and commonly used auxiliary drug in the biochemical experiments.It is the natural protein with single free cysteine.We used BSA as model protein to investigate the pH induced local environmental and conformational changes with molecular simulation and fluorescent methodology.
文摘A molecular dynamics (MD) simulation is performed on a DNA photolyase to study the conformational behavior of the photoactive cofactor flavin adenine dinucleotide (FAD) inside the enzyme pocket. A DNA photolyase is a highly efficient light-driven enzyme that repairs the UV-induced cyclobutane pyrimidine dimer in damaged DNA. In this work, the FAD conformational and dynamic changes were studied within the total complex structure of a DNA photolyase protein (containing FADH–, MTHF, and DNA molecules) embedded in a water solvent. We aimed to compare the conformational changes of the FAD cofactor and other constituent fragments of the molecular system under consideration. The obtained results were discussed to gain insight into the light-driven mechanism of DNA repair by a DNA photolyase enzyme—based on the enzyme structure, the FAD mobility, and conformation shape.
基金supported by the National Natural Science Foundation of China(No.21975068)Natural Science Foundation of Hunan(No.2022JJ10008)+1 种基金Science and Technology and Development Foundation of Shenzhen(No.JCYJ20210324122403010)Natural Science Foundation of Changsha(No.kq2202152)。
文摘Achieving selectivity in cell penetrating peptide(CPP)design is crucial to mitigate systemic toxicity and enable precise targeting based on distinct cellular phenotypes.Herein,we designed an amphiphilic peptide,L17Yp,by incorporating phosphorylated tyrosine into natural occurring M-lycotoxin peptide,known for its potent membrane-lytic activity.This strategic modification induced a conformational shift,as confirmed by circular dichroism spectroscopy,transitioning it from its bioactiveα-helix conformation to an inactive random coli configuration,effectively shielding its membrane-penetrating capacity.Upon exposure to alkaline phosphatase,L17Yp undergoes enzymatic dephosphorylation,prompting a conformational shift that restores its membrane-transduction capabilities.This unique property hold promises for selective drug delivery.This work introduces an enzymatic approach for targeted perturbation of the cell membrane,offering promising prospects for precise drug delivery applications.
基金supported by the National Key Research and Development Project of China (Nos.2019YFA0904100 and 2017YFA0505400)the National Natural Science Foundation of China (Nos.22077117 and 31971152)the USTC Research Funds of the Double First-Class Initiative。
文摘Current resolved structures of GPCRs and G protein complexes provided important insights into G protein activation. However, the binding or dissociation of GPCRs with G protein is instantaneous and highly dynamic in the intracellular environment. The conformational dynamic of G protein still needs to be addressed. In this study, we applied ^(19)F solution NMR spectroscopy to monitor the conformational changes of G protein upon interact with detergent mimicking membrane and receptor. Our results show that there are two states equilibria in the G_(α)in apo states. The interaction of G_(α)with detergents will accelerate this conformational transformation and induce a state that tends to bind to GPCRs. Finally, the G_(α)proteins presented a fully activation state when they coupled to GPCRs.
基金supported by the Science and Technology Program of Fujian Province,China(No.2023R1014002)the National Natural Science Foundation of China(No.41471390).
文摘The toxicity of PM_(2.5)does not necessarily change synchronously with its mass concentration.In this study,the chemical composition(carbonaceous species,water-soluble ions,and metals)and oxidative potential(dithiothreitol assay,DTT)of PM_(2.5)were investigated in 2017/2018 and 2022 in Xiamen,China.The decrease rate of volume-normalized DTT(DTTv)(38%)was lower than that of PM_(2.5)(55%)between the two sampling periods.However,the mass-normalized DTT(DTTm)increased by 44%.Clear seasonal patterns with higher levels in winter were found for PM_(2.5),most chemical constituents and DTTv but not for DTTm.The large decrease in DTT activity(84%−92%)after the addition of EDTA suggested that watersoluble metals were the main contributors to DTT in Xiamen.The increased gap between the reconstructed and measured DTTv and the stronger correlations between the reconstructed/measured DTT ratio and carbonaceous species in 2022were observed.The decrease rates of the hazard index(32.5%)and lifetime cancer risk(9.1%)differed from those of PM_(2.5)and DTTv due to their different main contributors.The PMF-MLR model showed that the contributions(nmol/(min·m^(3)))of vehicle emission,coal+biomass burning,ship emission and secondary aerosol to DTTv in 2022 decreased by 63.0%,65.2%,66.5%,and 22.2%,respectively,compared to those in 2017/2018,which was consistent with the emission reduction of vehicle exhaust and coal consumption,the adoption of low-sulfur fuel oil used on board ships and the reduced production of WSOC.However,the contributions of dust+sea salt and industrial emission increased.
文摘A low temperature (LoTemp?) polymerase chain reaction (PCR), conducted at cycling temperatures not to exceed 85℃and catalyzed by a novel highly processive HiFi? DNA polymerase with proofreading function, was used to study the topological conformational changes of the human papillomavirus (HPV) L1 gene DNA fragments bound to the insoluble amorphous aluminum hydroxyphosphate sulfate (AAHS) adjuvant in the quadrivalent HPV vaccine, Gardasil?. L1 gene DNA fragments of HPV-11, HPV-18 and HPV-16 were detected in the AAHS particles by nested PCR, but all were lacking a region that was amplifiable by an MY09 degenerate primer. In addition, a pair of degenerate consensus GP6/MY11 primers was able to amplify a target segment of the HPV-11 L1 gene DNA and the HPV-18 L1 gene DNA bound to the AAHS particles as expected for any HPV DNA in the B-conformation. However, there was no co-amplification of the HPV-16 L1 gene DNA known to coexist in the same samples. The lack of co-amplification was verified by direct DNA sequencing of the PCR amplicons. The companion HPV-16 L1 gene DNA in the same sample required repeated PCRs with a pair of modified non-degenerate GP6/ MY11 primers for detection. This melting profile of the HPV-16 L1 gene DNA was similar to that of the HPV-16 L1 gene DNA recently discovered in the postmortem blood of a young woman who suffered a sudden unexpected death 6 months after Gardasil? vaccination. The findings suggest that the topological conformational changes in the HPV L1 gene DNA residues bound to the AAHS adjuvant may be genotype-related. The special non-B-conformation may prevent the HPV-16 L1 gene DNA from being degraded in the body of the vaccine recipients after in- tramuscular injection.
基金supported by US National Institutes of Health grant R01 AI44902 (to C Z )a Pre-doctoral Fellowship from the American Heart Association (to W C )
文摘Introduction Integrins are a large family of adhesion molecules broadly expressed on the surface of a wide variety of cells as heterodimers. Binding of integrins to ligands provides not only mechanical anchorage for the cell to another cell or
基金National Natural Science Foundation of China,No.41761003The Karst Science Research Center of Guizhou Province,No.U1812401。
文摘Terrestrial ecosystems heavily depend on vegetation,which responds to carbon dioxide(CO_(2))fertilization in hot and humid regions.The subtropical humid karst region is a hot and humid region;whether and to what extent CO_(2)fertilization affects vegetation changes in such regions remains unclear.In this study,we investigated the degree to which CO_(2)fertilization influences vegetation changes,along with their spatial and temporal differences,in the subtropical humid karst region using time-lag effect analysis,a random forest model,and multiple regression analysis.Results showed that CO_(2)fertilization plays an important role in vegetation changes,exhibiting clear spatial variations across different geomorphological zones,with its degree of influence ranging mainly between 11%and 25%.The highest contribution of CO_(2)fertilization was observed in the karst basin and non-karstic region,whereas the lowest contribution was found in the karst plateau region.Previous studies have primarily attributed vegetation changes in subtropical humid karst region to ecological engineering,leading to an overestimation of its contribution to these changes.The findings of this study enhance the understanding of the mechanism of vegetation changes in humid karst region and provide theoretical and practical insights for ecological and environmental protection in these regions.
文摘BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic implications and longterm management strategies.Vascular and metabolic factors are being thought to play a role in such autoimmune neuro-inflammatory disorders,apart from the obvious immune mediated damage.With the advent of optical coherence tomography angiography(OCTA),it is easy to pick up on these subclinical macular microvascular and structural changes.AIM To study the macular microvascular and structural changes on OCTA in atypical optic neuritis.METHODS This observational cross-sectional study involved 8 NMOSD and 17 MOGAD patients,diagnosed serologically,as well as 10 healthy controls.Macular vascular density(MVD)and ganglion cell+inner plexiform layer thickness(GCIPL)were studied using OCTA.RESULTS There was a significant reduction in MVD in NMOSD and MOGAD affected as well as unaffected eyes when compared with healthy controls.NMOSD and MOGAD affected eyes had significant GCIPL thinning compared with healthy controls.NMOSD unaffected eyes did not show significant GCIPL thinning compared to healthy controls in contrast to MOGAD unaffected eyes.On comparing NMOSD with MOGAD,there was no significant difference in terms of MVD or GCIPL in the affected or unaffected eyes.CONCLUSION Although significant microvascular and structural changes are present on OCTA between atypical optic neuritis and normal patients,they could not help in differentiating between NMOSD and MOGAD cases.
