Isolationism and expansionism are two themes of American diplomacy. From the beginning of the state’s history, isolationism and expansionism have manifested themselves as two policy imperatives in American diplomacy....Isolationism and expansionism are two themes of American diplomacy. From the beginning of the state’s history, isolationism and expansionism have manifested themselves as two policy imperatives in American diplomacy. On the surface, isolationism and expansionism represent contradictory attitudes and assumptions about America’s proper relationship with the outside world: isolationism advocates diplomatic and military non-entanglement in world affairs; expansionism urges active involvement in external affairs. But in a deeper sense, both isolationism and expansionism are manifestations of American sense of mission, the belief that the US has a special role to perform for all nations in the world. Isolationism is a passive approach to accomplish that mission: it emphasizes the exemplary nature of their country. Expansionism stresses the need for active involvement to achieve that mission; thus, is an active approach to American mission.展开更多
The American critic argues that the 2025 U.S.National Security Strategy,with its isolationist and confrontational approach towards allies and China,is a desperate fiction that undermines genuine American prosperity an...The American critic argues that the 2025 U.S.National Security Strategy,with its isolationist and confrontational approach towards allies and China,is a desperate fiction that undermines genuine American prosperity and security.展开更多
Standard bacterial suspensions play a crucial role in microbiological diagnosis.Traditional prepar-ation methods,which rely heavily on manual operations,face challenges such as poor reproducibility,low ef-ficiency,and...Standard bacterial suspensions play a crucial role in microbiological diagnosis.Traditional prepar-ation methods,which rely heavily on manual operations,face challenges such as poor reproducibility,low ef-ficiency,and biosafety concerns.In this study,we propose a high-precision automated colony extraction and separation system that combines large-field imaging and artificial intelligence(AI)to facilitate intelligent screening and localization of colonies.Firstly,a large-field imaging system was developed to capture high-resolution images of 90 mm Petri dishes,achieving a physical resolution of 13.2μm and an imaging speed of 13 frames per second.Subsequently,AI technology was employed for the automatic recognition and localiza-tion of colonies,enabling the selection of target colonies with diameters ranging from 1.9 to 2.3 mm.Next,a three-axis motion control platform was designed,accompanied by a path planning algorithm for the efficient extraction of colonies.An electronic pipette was employed for accurate colony collection.Additionally,a bacterial suspension concentration measurement module was developed,incorporating a 650 nm laser diode as the light source,achieving a measurement accuracy of 0.01 McFarland concentration(MCF).Finally,the system’s performance was validated through the preparation of an Esckerichia coli(E.coli)suspension.After 17 hours of cultivation,E.coli was extracted four times,achieving the target concentration set by the system.This work is expected to enable rapid and accurate microbial sample preparation,significantly reducing de-tection cycles and alleviating the workload of healthcare personnel.展开更多
Objective This study aims to investigate the joint associations of sarcopenia and social isolation with mortality risk.Methods Using data from the Chinese Longitudinal Healthy Longevity Survey(CLHLS)and the UK Biobank...Objective This study aims to investigate the joint associations of sarcopenia and social isolation with mortality risk.Methods Using data from the Chinese Longitudinal Healthy Longevity Survey(CLHLS)and the UK Biobank,sarcopenia was diagnosed according to European and Asian Working Groups for Sarcopenia criteria.Social isolation was assessed using standardized questionnaires,including questions on solitude,frequency of social activities,contact with others,and marital status(for the CLHLS only).Results During the follow-up period,8,249 deaths occurred in the CLHLS and 26,670 deaths in the UK Biobank groups.While no significant interaction was observed between sarcopenia and social isolation in predicting all-cause mortality in the CLHLS cohort,the association between social isolation and mortality was stronger among individuals with sarcopenia in the UK Biobank(P-interaction=0.03,relative risk due to interaction:0.23,95%confidence interval[CI]:0.06–0.41).Further joint analyses showed that participants with sarcopenia and high levels of social isolation had the highest mortality risk(hazard ration[HR]:1.99;95%CI:[1.74–2.28]in the CLHLS and 1.69[1.55–1.85]in the UK Biobank)compared to those without either condition.Conclusion The combination of social isolation and sarcopenia synergistically increases the risk of mortality in middle-aged and older adults across diverse populations.展开更多
The first hemiterpene-quassinoid adducts,bruquass A and B(1 and 2),were rapidly isolated and identified from Brucea javanica using an integrated analytical strategy.They possessed unusual carbon skeletons formed by th...The first hemiterpene-quassinoid adducts,bruquass A and B(1 and 2),were rapidly isolated and identified from Brucea javanica using an integrated analytical strategy.They possessed unusual carbon skeletons formed by the coupling of quassinoids with hemiterpene units via vinylogous aldol reactions.Their structural configurations were determined through comprehensive spectroscopic analysis and electronic circular dichroism(ECD) calculations.Plausible biosynthetic pathways for 1 and 2 were proposed,and guided by these biogenetic insights,the biomimetic synthesis of compound 1 was successfully achieved.Furthermore,compounds 1 and 2 exhibited significant antifeedant activity against Plutella xylostella.The bioactivity assessment results open up the prospects of 1 and 2 as a promising new class of botanical insecticide.展开更多
Isolation technology can reduce the type of structural damage that earthquakes cause.A new type of composite sliding-rolling friction composite seismic isolation bearing(SRF)with composite sliding friction and rolling...Isolation technology can reduce the type of structural damage that earthquakes cause.A new type of composite sliding-rolling friction composite seismic isolation bearing(SRF)with composite sliding friction and rolling friction is proposed.SRF is capable of realizing a parallel arrangement of sliding friction and rolling friction,and the coefficient of dynamic friction shows variability.The proposed static tests on composite bearings were conducted to investigate the effects of the number of shims,loading speed and vertical pressure on the dynamic friction factor.Test results show that the coefficient of dynamic friction first generally decreases and then increases with an increase in sliding speed,prior to again decreasing with an increase in vertical pressure.The dynamic friction factor increases and then decreases with an increase in the number of shims for a four-roll ball.It decreases and then increases with an increase in the number of shims for a five-roll ball.Based on finite element analysis,modeling and analyzing the effects of the coefficient of friction,the number of balls and the number of shims on the hysteresis performance of the support and derive its skeleton curve.The SRF hysteretic performance,dynamic friction factor and the number of rolling balls and shims show significant correlation.展开更多
Natural hybridization is known to play a vital role in speciation;however,the mechanisms underlying the early stages of natural hybridization remain unclear.Where two plant species come into contact,two driving forces...Natural hybridization is known to play a vital role in speciation;however,the mechanisms underlying the early stages of natural hybridization remain unclear.Where two plant species come into contact,two driving forces may balance the dynamic consequences of hybridization:fusion by hybridization-mediated gene flow,and separation by reproductive isolation(RI)(Ma et al.,2010a,b;Chang et al.,2022).展开更多
Developments over the past year have led to serious, widespread concern that the world could be returning to a more isolationist stance. It is perhaps the greatest threat ever levelled at the post-war globalization mo...Developments over the past year have led to serious, widespread concern that the world could be returning to a more isolationist stance. It is perhaps the greatest threat ever levelled at the post-war globalization movement and all of its supporting architecture. This paper argues that due to the unusual nature of the last business cycle, the general public has become impatient with the existing economic and in particular, international trade architecture. It also points out that its typical defenders are unsure of how to do so. In response, what is suggested is that logic puts definite limits on how much change is actually likely to occur, and if so, which strategic responses are most appropriate.展开更多
Despite intensive research on solar-driven photocatalytic overall water splitting(POWS),the overall efficiencies remain insufficient to meet commercial standards.As a central challenge in realizing this technology mai...Despite intensive research on solar-driven photocatalytic overall water splitting(POWS),the overall efficiencies remain insufficient to meet commercial standards.As a central challenge in realizing this technology mainly lies in the precise tuning and rational designing of highly efficient materials and photocatalytic systems,which is paramount for its unlocking scalable,practical applications.However,novel materials fabrication and advanced photocatalytic systems are essential for overcoming intrinsic limitations of conventional catalysts by enabling this green technology to resolve global energy crisis.Therefore,this review critically explores the engineering developments in POWS process and novel photocatalyst designing,via shifting from simple bandgap engineering to more advanced charge carrier dynamics control via utilizing one/two-step photocatalytic excitation system,surface phase junctions i.e.,Z-scheme and S-scheme heterojunctions,surface modification,morphological tuning,and the role of co-catalysts,to control sluggish kinetics,promote oxygen evolution reaction(OER)and suppress undesirable H2/O2,backward reaction with superior visible light absorption capacity to produce remarkable energy production.Moreover,we critically discuss the recent trend of POWS from a materials discovery phase to demanding engineering and mechanistic optimization phase with viable economic viability,which requires bridging the gap between excellent lab-scale performance to stringent stability,cost,and high efficiency demands of industrial-scale solar fuel production.In addition,the currents challenges and future directions are also enclosed in detail for sustainable energy production.展开更多
Accurate identification of water sources is crucial for effective water management and safety in mining operations.However,imbalanced water sample datasets often lead to suboptimal classification accuracy.To address t...Accurate identification of water sources is crucial for effective water management and safety in mining operations.However,imbalanced water sample datasets often lead to suboptimal classification accuracy.To address this challenge,this study proposes a novel water source identification method integrating Synthetic Minority Over-Sampling Technique(SMOTE),Zebra Optimization Algorithm(ZOA),and Light Gradient Boosting Machine(LightGBM).Initially,SMOTE is utilized to synthesize samples for the minority class within the imbalanced dataset,thereby generating a balanced water sample dataset and mitigating class distribution disparities.Subsequently,an efficient water source identification model is constructed by combining ZOA with LightGBM,leveraging the strengths of both algorithms.The model’s performance is validated using a test set and compared with other common classification models.Results demonstrate that SMOTE significantly alleviates class imbalance and enhances the classification accuracy of LightGBM for minority class water samples.ZOA parameter tuning accelerates model convergence and further improves classification accuracy,optimizing the model’s overall performance.In experimental validation,the proposed SMOTE-ZOA-LightGBM model achieved an accuracy of 88.41%and a F1 score of 88.24%,outperforming six other classification models.The method proposed in this paper can accurately identify water source types,effectively addressing the issue of low classification accuracy caused by imbalanced water sample data.It provides reliable technical support and scientific basis for identifying and preventing water inrush sources in mines.展开更多
To address the issues of high costs and low component utilization caused by the independent configuration of hybrid DC circuit breakers(HCBs)and DC power flow controllers(DCPFCs)at each port in existing DC distributio...To address the issues of high costs and low component utilization caused by the independent configuration of hybrid DC circuit breakers(HCBs)and DC power flow controllers(DCPFCs)at each port in existing DC distribution networks,this paper adopts a component sharing mechanism to propose a composite multi-port hybrid DC circuit breaker(CM-HCB)with DC power flow and fault current limitation abilities,as well as reduced component costs.The proposed CM-HCB topology enables the sharing of the main breaker branch(MB)and the energy dissipation branch,while the load commutation switches(LCSs)in the main branch are reused as power flow control components,enabling flexible regulation of power flow in multiple lines.Meanwhile,by reconstructing the current path during the fault process,the proposed CM-HCB can utilize the internal coupled inductor to limit the current rise rate at the initial stage of the fault,significantly reducing the requirement for breaking current.A detailed study on the topological structure,steady-state power flow regulation mechanism,transient fault isolation mechanism,control strategy and characteristic analysis of the proposed CM-HCB is presented.Then,a Matlab/Simulink-based meshed three-terminal DC grid simulation platform with the proposed CM-HCB is built.The results indicate that the proposed CM-HCB can not only achieve flexible power flow control during steady-state operation,but also obtain current rise limitation and fault isolation abilities under short-circuit fault conditions,verifying its correctness and effectiveness.Finally,a comparative economic analysis is conducted between the proposed CM-HCB and the other two existing solutions,confirming that its component sharing mechanism can significantly reduce the number of components,lower system costs,and improve component utilization.展开更多
A novel vibration isolation system designed for superior performance in low-frequency environments is proposed in this work.The isolator is based on a unique hexagonal arrangement of linear springs,allowing for an adj...A novel vibration isolation system designed for superior performance in low-frequency environments is proposed in this work.The isolator is based on a unique hexagonal arrangement of linear springs,allowing for an adjustable geometric configuration via the initial inclination angle.Based on the principle of Lagrangian mechanics,the equation of motion governing the structural dynamics is rigorously derived.The system is modeled as a strongly nonlinear single-degree-of-freedom dynamical system,loaded with a normalized payload and subject to harmonic base excitation.To analyze the steady-state response,the harmonic balance method is employed,providing accurate predictions of the payload's vibration amplitude and displacement transmissibility as functions of both the base excitation amplitude and frequency.The analysis reveals a direct relationship between the isolator's geometric and stiffness parameters and its load-bearing capacity,leading to the identification of three distinct operational regimes.Depending on the unloaded initial inclination angle,the equivalent stiffness ratio,and the payload design configuration,the system can exhibit one of three vibration isolation modes:(i)the quasizero stiffness(QZS)isolation mode,(ii)the zero linear stiffness with controllable nonlinear stiffness,and(iii)the full-band perfect zero stiffness.The vibration isolation performance of the proposed structure is thoroughly discussed for all three oscillation modes in terms of frequency response curves,displacement transmissibility,and time-domain responses.The key novel finding is that this structure can operate as a full-band,high-performance vibration isolator when the initial inclination angle is designed to be a right angle,enabling full isolation of the maximum possible payload.Moreover,the analytical results and numerical simulations demonstrate that the isolator's displacement transmissibility T with the unit dB tends to-∞as the air-damping coefficient approaches zero,enabling ideal vibration isolation across the entire excitation frequency range.These analytical insights are validated through comprehensive numerical simulations,which show excellent agreement with the theoretical predictions.展开更多
This study employed tri-component continuous monitoring data from 10 measurement points on both sides of a base isolation layer in the basement of a large-span high-rise building in Beijing,as well as from a free-fiel...This study employed tri-component continuous monitoring data from 10 measurement points on both sides of a base isolation layer in the basement of a large-span high-rise building in Beijing,as well as from a free-field station and roof frame,during a Mw 5.5 magnitude earthquake in Pingyuan,Shandong,in 2023.The H/V spectral ratio method was used to evaluate the structural dynamic response characteristics of the building and analyze the regulatory effect of the base-isolation layer on seismic waves.The results indicate that during the earthquake,the peak frequency of the free-field and the measurement points below the base-isolation layer was stable at 0.17 Hz,whereas the main frequency of the measurement points above the base-isolation layer increased to 0.75–1.18 Hz,which is 4–6 times greater than that of the points below.The amplitude was suppressed by more than 70%,confirming that the base isolation layer effectively isolated the low-frequency energy from the ground and increased the response frequency of the building.When the building was excited by an earthquake,a three-tier frequency gradient was formed throughout the building:“base-isolation layer(0.17 Hz)-main body(1.18 Hz)-roof frame(3.83 Hz)”,which can effectively avoid resonance of the entire building.In addition,the composite base-isolation device changed the dynamic characteristics of the structure.The resonance period was extended from 0.74 s(theoretical value without base isolation)to 5.9 s(calculated value),and the resonance frequency was reduced from 1.35 to 0.17 Hz.This finding indicates that the base-isolation layer can enhance seismic performance by increasing flexibility and damping.展开更多
Frugal innovation stands as an imperative cog in the wheel of sustainable development.In the pursuit of simplicity,cost-effectiveness,and environmental compatibility,waste tire rubber and polyurethane-coated rubber(PU...Frugal innovation stands as an imperative cog in the wheel of sustainable development.In the pursuit of simplicity,cost-effectiveness,and environmental compatibility,waste tire rubber and polyurethane-coated rubber(PUcR)emerge as pivotal components in sustainable practices.These materials are advocated for various purposes,including protecting utility tunnels,serving as railway subgrades,and enhancing structural resilience through geotechnical seismic isolation(GSI).Their inherent characteristics,such as modest shear modulus(G)and robust damping ratio(D),make them well-suited for such endeavors,contributing to sustainability goals by repurposing substantial quantities of non-biodegradable waste.For practicality,leveraging artificial intelligence(AI)-based modern computing techniques for recycled material applications is imperative.In this regard,gene expression programming(GEP)was utilized to develop models for predicting the G and D of rubber–soil mixtures(RSMs)and polyurethane-coated RSMs(PUcRSMs).Employing laboratory testing data from 63 samples across three soil types,the newly proposed models demonstrated exceptional accuracy,with correlation coefficient(R^(2))values of 0.91 and 0.97 for G-prediction of RSM and PUcRSM,and 0.9 and 0.86 for D-prediction,respectively.Using AI-based methods,such as GEP to predict mixtures’dynamic response can cut laboratory costs and optimize mix designs,thereby advancing sustainable material applications.展开更多
Ischemic stroke is a secondary cause of mortality worldwide,imposing considerable medical and economic burdens on society.Extracellular vesicles,serving as natural nanocarriers for drug delivery,exhibit excellent bioc...Ischemic stroke is a secondary cause of mortality worldwide,imposing considerable medical and economic burdens on society.Extracellular vesicles,serving as natural nanocarriers for drug delivery,exhibit excellent biocompatibility in vivo and have significant advantages in the management of ischemic stroke.However,the uncertain distribution and rapid clearance of extracellular vesicles impede their delivery efficiency.By utilizing membrane decoration or by encapsulating therapeutic cargo within extracellular vesicles,their delivery efficacy may be greatly improved.Furthermore,previous studies have indicated that microvesicles,a subset of large-sized extracellular vesicles,can transport mitochondria to neighboring cells,thereby aiding in the restoration of mitochondrial function post-ischemic stroke.Small extracellular vesicles have also demonstrated the capability to transfer mitochondrial components,such as proteins or deoxyribonucleic acid,or their sub-components,for extracellular vesicle-based ischemic stroke therapy.In this review,we undertake a comparative analysis of the isolation techniques employed for extracellular vesicles and present an overview of the current dominant extracellular vesicle modification methodologies.Given the complex facets of treating ischemic stroke,we also delineate various extracellular vesicle modification approaches which are suited to different facets of the treatment process.Moreover,given the burgeoning interest in mitochondrial delivery,we delved into the feasibility and existing research findings on the transportation of mitochondrial fractions or intact mitochondria through small extracellular vesicles and microvesicles to offer a fresh perspective on ischemic stroke therapy.展开更多
The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow ...The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow controller(CFC)are demanded to ensure the multiterminal DC grid to operates reliably and flexibly.However,since the CFC and the DCCB are all based on fully controlled semiconductor switches(e.g.,insulated gate bipolar transistor,integrated gate commutated thyristor,etc.),their separation configuration in the multiterminal DC grid will lead to unaffordable implementation costs and conduction power losses.To solve these problems,integrated equipment with both current flow control and fault isolation abilities is proposed,which shares the expensive and duplicated components of CFCs and DCCBs among adjacent lines.In addition,the complicated coordination control of CFCs and DCCBs can be avoided by adopting the integrated equipment in themultiterminal DC grid.In order to examine the current flow control and fault isolation abilities of the integrated equipment,the simulation model of a specific meshed four-terminal DC grid is constructed in the PSCAD/EMTDC software.Finally,the comparison between the integrated equipment and the separate solution is presented a specific result or conclusion needs to be added to the abstract.展开更多
Quasi-zero-stiffness(QZS)metamaterials have attracted significant interest for application in low-frequency vibration isolation.However,previous work has been limited by the design mechanism of QZS metamaterials,as it...Quasi-zero-stiffness(QZS)metamaterials have attracted significant interest for application in low-frequency vibration isolation.However,previous work has been limited by the design mechanism of QZS metamaterials,as it is still difficult to achieve a simplified structure suitable for practical engineering applications.Here,we introduce a class of programmable QZS metamaterials and a novel design mechanism that address this long-standing difficulty.The proposed QZS metamaterials are formed by an array of representative unit cells(RUCs)with the expected QZS features,where the QZS features of the RUC are tailored by means of a structural bionic mechanism.In our experiments,we validate the QZS features exhibited by the RUCs,the programmable QZS behavior,and the potential promising applications of these programmable QZS metamaterials in low-frequency vibration isolation.The obtained results could inspire a new class of programmable QZS metamaterials for low-frequency vibration isolation in current and future mechanical and other engineering applications.展开更多
Geological analysis,despite being a long-term method for identifying adverse geology in tunnels,has significant limitations due to its reliance on empirical analysis.The quantitative aspects of geochemical anomalies a...Geological analysis,despite being a long-term method for identifying adverse geology in tunnels,has significant limitations due to its reliance on empirical analysis.The quantitative aspects of geochemical anomalies associated with adverse geology provide a novel strategy for addressing these limitations.However,statistical methods for identifying geochemical anomalies are insufficient for tunnel engineering.In contrast,data mining techniques such as machine learning have demonstrated greater efficacy when applied to geological data.Herein,a method for identifying adverse geology using machine learning of geochemical anomalies is proposed.The method was identified geochemical anomalies in tunnel that were not identified by statistical methods.We by employing robust factor analysis and self-organizing maps to reduce the dimensionality of geochemical data and extract the anomaly elements combination(AEC).Using the AEC sample data,we trained an isolation forest model to identify the multi-element anomalies,successfully.We analyzed the adverse geological features based the multi-element anomalies.This study,therefore,extends the traditional approach of geological analysis in tunnels and demonstrates that machine learning is an effective tool for intelligent geological analysis.Correspondingly,the research offers new insights regarding the adverse geology and the prevention of hazards during the construction of tunnels and underground engineering projects.展开更多
Objective Observational studies have shown inconsistent associations of loneliness or social isolation(SI)with ischemic heart disease(IHD),with unknown mediators.Methods Using data from genome-wide association studies...Objective Observational studies have shown inconsistent associations of loneliness or social isolation(SI)with ischemic heart disease(IHD),with unknown mediators.Methods Using data from genome-wide association studies of predominantly European ancestry,we performed a bidirectional two-sample Mendelian Randomization(MR)study to estimate causal effects of loneliness(N=487,647)and SI traits on IHD(N=184,305).SI traits included whether individuals lived alone,participated in various types of social activities,and how often they had contact with friends or family(N=459,830 to 461,369).A network MR study was conducted to evaluate the mediating roles of 20 candidate mediators,including metabolic,behavioral and psychological factors.Results Loneliness increased IHD risk(OR=2.129;95%confidence interval[CI]:1.380 to 3.285),mediated by body fat percentage,waist-hip ratio,total cholesterol,and low-density lipoprotein cholesterol.For SI traits,only fewer social activities increased IHD risk(OR=1.815;95%CI:1.189 to 2.772),mediated by hypertension,high-density lipoprotein cholesterol,triglycerides,fasting insulin,and smoking cessation.No reverse causality of IHD with loneliness and SI was found.Conclusion These findings suggested more attention should be paid to individuals who feel lonely and have fewer social activities to prevent IHD,with several mediators as prioritized targets for intervention.展开更多
文摘Isolationism and expansionism are two themes of American diplomacy. From the beginning of the state’s history, isolationism and expansionism have manifested themselves as two policy imperatives in American diplomacy. On the surface, isolationism and expansionism represent contradictory attitudes and assumptions about America’s proper relationship with the outside world: isolationism advocates diplomatic and military non-entanglement in world affairs; expansionism urges active involvement in external affairs. But in a deeper sense, both isolationism and expansionism are manifestations of American sense of mission, the belief that the US has a special role to perform for all nations in the world. Isolationism is a passive approach to accomplish that mission: it emphasizes the exemplary nature of their country. Expansionism stresses the need for active involvement to achieve that mission; thus, is an active approach to American mission.
文摘The American critic argues that the 2025 U.S.National Security Strategy,with its isolationist and confrontational approach towards allies and China,is a desperate fiction that undermines genuine American prosperity and security.
文摘Standard bacterial suspensions play a crucial role in microbiological diagnosis.Traditional prepar-ation methods,which rely heavily on manual operations,face challenges such as poor reproducibility,low ef-ficiency,and biosafety concerns.In this study,we propose a high-precision automated colony extraction and separation system that combines large-field imaging and artificial intelligence(AI)to facilitate intelligent screening and localization of colonies.Firstly,a large-field imaging system was developed to capture high-resolution images of 90 mm Petri dishes,achieving a physical resolution of 13.2μm and an imaging speed of 13 frames per second.Subsequently,AI technology was employed for the automatic recognition and localiza-tion of colonies,enabling the selection of target colonies with diameters ranging from 1.9 to 2.3 mm.Next,a three-axis motion control platform was designed,accompanied by a path planning algorithm for the efficient extraction of colonies.An electronic pipette was employed for accurate colony collection.Additionally,a bacterial suspension concentration measurement module was developed,incorporating a 650 nm laser diode as the light source,achieving a measurement accuracy of 0.01 McFarland concentration(MCF).Finally,the system’s performance was validated through the preparation of an Esckerichia coli(E.coli)suspension.After 17 hours of cultivation,E.coli was extracted four times,achieving the target concentration set by the system.This work is expected to enable rapid and accurate microbial sample preparation,significantly reducing de-tection cycles and alleviating the workload of healthcare personnel.
基金supported by grants from the National Key Research and Development Program of China(No.2023YFC3606300,No.2022YFC3600300)the National Natural Science Foundation of China(No.82325043)the National Key Research and Development Program of Hubei Province(2022BCA036)。
文摘Objective This study aims to investigate the joint associations of sarcopenia and social isolation with mortality risk.Methods Using data from the Chinese Longitudinal Healthy Longevity Survey(CLHLS)and the UK Biobank,sarcopenia was diagnosed according to European and Asian Working Groups for Sarcopenia criteria.Social isolation was assessed using standardized questionnaires,including questions on solitude,frequency of social activities,contact with others,and marital status(for the CLHLS only).Results During the follow-up period,8,249 deaths occurred in the CLHLS and 26,670 deaths in the UK Biobank groups.While no significant interaction was observed between sarcopenia and social isolation in predicting all-cause mortality in the CLHLS cohort,the association between social isolation and mortality was stronger among individuals with sarcopenia in the UK Biobank(P-interaction=0.03,relative risk due to interaction:0.23,95%confidence interval[CI]:0.06–0.41).Further joint analyses showed that participants with sarcopenia and high levels of social isolation had the highest mortality risk(hazard ration[HR]:1.99;95%CI:[1.74–2.28]in the CLHLS and 1.69[1.55–1.85]in the UK Biobank)compared to those without either condition.Conclusion The combination of social isolation and sarcopenia synergistically increases the risk of mortality in middle-aged and older adults across diverse populations.
基金funded by the National Natural Science Foundation Regional Innovation and Development Joint Fund(No.U22A20381)National Key R&D Program of China (No.2024YFC3506600)+3 种基金Natural Science Foundation of Liaoning Province of China (No.2024-MS-086)Shenyang City Middle and Young Science and Technology Talents Cultivation Special U40 Outstanding Youth Project (No.RC230803)Science and Technology Planning Project of Liaoning Province (No.2021JH1/10400049)Song Shaojiang Expert Workstation of Yunnan Province (No.202305AF150030)。
文摘The first hemiterpene-quassinoid adducts,bruquass A and B(1 and 2),were rapidly isolated and identified from Brucea javanica using an integrated analytical strategy.They possessed unusual carbon skeletons formed by the coupling of quassinoids with hemiterpene units via vinylogous aldol reactions.Their structural configurations were determined through comprehensive spectroscopic analysis and electronic circular dichroism(ECD) calculations.Plausible biosynthetic pathways for 1 and 2 were proposed,and guided by these biogenetic insights,the biomimetic synthesis of compound 1 was successfully achieved.Furthermore,compounds 1 and 2 exhibited significant antifeedant activity against Plutella xylostella.The bioactivity assessment results open up the prospects of 1 and 2 as a promising new class of botanical insecticide.
文摘Isolation technology can reduce the type of structural damage that earthquakes cause.A new type of composite sliding-rolling friction composite seismic isolation bearing(SRF)with composite sliding friction and rolling friction is proposed.SRF is capable of realizing a parallel arrangement of sliding friction and rolling friction,and the coefficient of dynamic friction shows variability.The proposed static tests on composite bearings were conducted to investigate the effects of the number of shims,loading speed and vertical pressure on the dynamic friction factor.Test results show that the coefficient of dynamic friction first generally decreases and then increases with an increase in sliding speed,prior to again decreasing with an increase in vertical pressure.The dynamic friction factor increases and then decreases with an increase in the number of shims for a four-roll ball.It decreases and then increases with an increase in the number of shims for a five-roll ball.Based on finite element analysis,modeling and analyzing the effects of the coefficient of friction,the number of balls and the number of shims on the hysteresis performance of the support and derive its skeleton curve.The SRF hysteretic performance,dynamic friction factor and the number of rolling balls and shims show significant correlation.
基金supported by the National Natural Science Foundation of China(U23A20160,32360336)Guizhou Provincial Key Technology R&D Program(Qian KeHe ZhiCheng[2023]YiBan035).
文摘Natural hybridization is known to play a vital role in speciation;however,the mechanisms underlying the early stages of natural hybridization remain unclear.Where two plant species come into contact,two driving forces may balance the dynamic consequences of hybridization:fusion by hybridization-mediated gene flow,and separation by reproductive isolation(RI)(Ma et al.,2010a,b;Chang et al.,2022).
文摘Developments over the past year have led to serious, widespread concern that the world could be returning to a more isolationist stance. It is perhaps the greatest threat ever levelled at the post-war globalization movement and all of its supporting architecture. This paper argues that due to the unusual nature of the last business cycle, the general public has become impatient with the existing economic and in particular, international trade architecture. It also points out that its typical defenders are unsure of how to do so. In response, what is suggested is that logic puts definite limits on how much change is actually likely to occur, and if so, which strategic responses are most appropriate.
基金the Taizhou University,Zhejiang,China for funding(No.T20250101215)the Deanship of research and Graduate Studies at King Khalid University for funding this work through Large Research Project(R.G.P.2/398/46).
文摘Despite intensive research on solar-driven photocatalytic overall water splitting(POWS),the overall efficiencies remain insufficient to meet commercial standards.As a central challenge in realizing this technology mainly lies in the precise tuning and rational designing of highly efficient materials and photocatalytic systems,which is paramount for its unlocking scalable,practical applications.However,novel materials fabrication and advanced photocatalytic systems are essential for overcoming intrinsic limitations of conventional catalysts by enabling this green technology to resolve global energy crisis.Therefore,this review critically explores the engineering developments in POWS process and novel photocatalyst designing,via shifting from simple bandgap engineering to more advanced charge carrier dynamics control via utilizing one/two-step photocatalytic excitation system,surface phase junctions i.e.,Z-scheme and S-scheme heterojunctions,surface modification,morphological tuning,and the role of co-catalysts,to control sluggish kinetics,promote oxygen evolution reaction(OER)and suppress undesirable H2/O2,backward reaction with superior visible light absorption capacity to produce remarkable energy production.Moreover,we critically discuss the recent trend of POWS from a materials discovery phase to demanding engineering and mechanistic optimization phase with viable economic viability,which requires bridging the gap between excellent lab-scale performance to stringent stability,cost,and high efficiency demands of industrial-scale solar fuel production.In addition,the currents challenges and future directions are also enclosed in detail for sustainable energy production.
基金funding from the Natural Science Foundation of Henan Province(252300421852)the State Key Laboratory of Development and Comprehensive Utilization of Coking Coal Resources(41040220201308)+4 种基金the National Natural Science Foundation of China(41972254)the China Postdoctoral Science Foundation(2019M662494)Supported by the Key Scientific Research Projects of Higher Education Institutions of Henan Province(19A170005)the Fundamental Research Funds for the Universities of Henan Province(NSFRF200337,NSFRF200103)Key Research and Development Project of Henan Province(251111322300).
文摘Accurate identification of water sources is crucial for effective water management and safety in mining operations.However,imbalanced water sample datasets often lead to suboptimal classification accuracy.To address this challenge,this study proposes a novel water source identification method integrating Synthetic Minority Over-Sampling Technique(SMOTE),Zebra Optimization Algorithm(ZOA),and Light Gradient Boosting Machine(LightGBM).Initially,SMOTE is utilized to synthesize samples for the minority class within the imbalanced dataset,thereby generating a balanced water sample dataset and mitigating class distribution disparities.Subsequently,an efficient water source identification model is constructed by combining ZOA with LightGBM,leveraging the strengths of both algorithms.The model’s performance is validated using a test set and compared with other common classification models.Results demonstrate that SMOTE significantly alleviates class imbalance and enhances the classification accuracy of LightGBM for minority class water samples.ZOA parameter tuning accelerates model convergence and further improves classification accuracy,optimizing the model’s overall performance.In experimental validation,the proposed SMOTE-ZOA-LightGBM model achieved an accuracy of 88.41%and a F1 score of 88.24%,outperforming six other classification models.The method proposed in this paper can accurately identify water source types,effectively addressing the issue of low classification accuracy caused by imbalanced water sample data.It provides reliable technical support and scientific basis for identifying and preventing water inrush sources in mines.
基金funded by Youth Talent Growth Project of Guizhou Provincial Department of Education(No.Qianjiaoji[2024]21)National Natural Science Foundation of China(No.62461008 and No.52507211)Guizhou Provincial Key Technology R&D Program(No.[2024]General 049).
文摘To address the issues of high costs and low component utilization caused by the independent configuration of hybrid DC circuit breakers(HCBs)and DC power flow controllers(DCPFCs)at each port in existing DC distribution networks,this paper adopts a component sharing mechanism to propose a composite multi-port hybrid DC circuit breaker(CM-HCB)with DC power flow and fault current limitation abilities,as well as reduced component costs.The proposed CM-HCB topology enables the sharing of the main breaker branch(MB)and the energy dissipation branch,while the load commutation switches(LCSs)in the main branch are reused as power flow control components,enabling flexible regulation of power flow in multiple lines.Meanwhile,by reconstructing the current path during the fault process,the proposed CM-HCB can utilize the internal coupled inductor to limit the current rise rate at the initial stage of the fault,significantly reducing the requirement for breaking current.A detailed study on the topological structure,steady-state power flow regulation mechanism,transient fault isolation mechanism,control strategy and characteristic analysis of the proposed CM-HCB is presented.Then,a Matlab/Simulink-based meshed three-terminal DC grid simulation platform with the proposed CM-HCB is built.The results indicate that the proposed CM-HCB can not only achieve flexible power flow control during steady-state operation,but also obtain current rise limitation and fault isolation abilities under short-circuit fault conditions,verifying its correctness and effectiveness.Finally,a comparative economic analysis is conducted between the proposed CM-HCB and the other two existing solutions,confirming that its component sharing mechanism can significantly reduce the number of components,lower system costs,and improve component utilization.
基金Project supported by the National Key R&D Program of China(No.2023YFE0125900)。
文摘A novel vibration isolation system designed for superior performance in low-frequency environments is proposed in this work.The isolator is based on a unique hexagonal arrangement of linear springs,allowing for an adjustable geometric configuration via the initial inclination angle.Based on the principle of Lagrangian mechanics,the equation of motion governing the structural dynamics is rigorously derived.The system is modeled as a strongly nonlinear single-degree-of-freedom dynamical system,loaded with a normalized payload and subject to harmonic base excitation.To analyze the steady-state response,the harmonic balance method is employed,providing accurate predictions of the payload's vibration amplitude and displacement transmissibility as functions of both the base excitation amplitude and frequency.The analysis reveals a direct relationship between the isolator's geometric and stiffness parameters and its load-bearing capacity,leading to the identification of three distinct operational regimes.Depending on the unloaded initial inclination angle,the equivalent stiffness ratio,and the payload design configuration,the system can exhibit one of three vibration isolation modes:(i)the quasizero stiffness(QZS)isolation mode,(ii)the zero linear stiffness with controllable nonlinear stiffness,and(iii)the full-band perfect zero stiffness.The vibration isolation performance of the proposed structure is thoroughly discussed for all three oscillation modes in terms of frequency response curves,displacement transmissibility,and time-domain responses.The key novel finding is that this structure can operate as a full-band,high-performance vibration isolator when the initial inclination angle is designed to be a right angle,enabling full isolation of the maximum possible payload.Moreover,the analytical results and numerical simulations demonstrate that the isolator's displacement transmissibility T with the unit dB tends to-∞as the air-damping coefficient approaches zero,enabling ideal vibration isolation across the entire excitation frequency range.These analytical insights are validated through comprehensive numerical simulations,which show excellent agreement with the theoretical predictions.
基金supported by the Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project(Grant No.2025ZD005100)by Beijing Geolight Technology Co.,Ltd.under the project“The Impact of Strong Ground Motion on Buildings”(YF-202520).
文摘This study employed tri-component continuous monitoring data from 10 measurement points on both sides of a base isolation layer in the basement of a large-span high-rise building in Beijing,as well as from a free-field station and roof frame,during a Mw 5.5 magnitude earthquake in Pingyuan,Shandong,in 2023.The H/V spectral ratio method was used to evaluate the structural dynamic response characteristics of the building and analyze the regulatory effect of the base-isolation layer on seismic waves.The results indicate that during the earthquake,the peak frequency of the free-field and the measurement points below the base-isolation layer was stable at 0.17 Hz,whereas the main frequency of the measurement points above the base-isolation layer increased to 0.75–1.18 Hz,which is 4–6 times greater than that of the points below.The amplitude was suppressed by more than 70%,confirming that the base isolation layer effectively isolated the low-frequency energy from the ground and increased the response frequency of the building.When the building was excited by an earthquake,a three-tier frequency gradient was formed throughout the building:“base-isolation layer(0.17 Hz)-main body(1.18 Hz)-roof frame(3.83 Hz)”,which can effectively avoid resonance of the entire building.In addition,the composite base-isolation device changed the dynamic characteristics of the structure.The resonance period was extended from 0.74 s(theoretical value without base isolation)to 5.9 s(calculated value),and the resonance frequency was reduced from 1.35 to 0.17 Hz.This finding indicates that the base-isolation layer can enhance seismic performance by increasing flexibility and damping.
文摘Frugal innovation stands as an imperative cog in the wheel of sustainable development.In the pursuit of simplicity,cost-effectiveness,and environmental compatibility,waste tire rubber and polyurethane-coated rubber(PUcR)emerge as pivotal components in sustainable practices.These materials are advocated for various purposes,including protecting utility tunnels,serving as railway subgrades,and enhancing structural resilience through geotechnical seismic isolation(GSI).Their inherent characteristics,such as modest shear modulus(G)and robust damping ratio(D),make them well-suited for such endeavors,contributing to sustainability goals by repurposing substantial quantities of non-biodegradable waste.For practicality,leveraging artificial intelligence(AI)-based modern computing techniques for recycled material applications is imperative.In this regard,gene expression programming(GEP)was utilized to develop models for predicting the G and D of rubber–soil mixtures(RSMs)and polyurethane-coated RSMs(PUcRSMs).Employing laboratory testing data from 63 samples across three soil types,the newly proposed models demonstrated exceptional accuracy,with correlation coefficient(R^(2))values of 0.91 and 0.97 for G-prediction of RSM and PUcRSM,and 0.9 and 0.86 for D-prediction,respectively.Using AI-based methods,such as GEP to predict mixtures’dynamic response can cut laboratory costs and optimize mix designs,thereby advancing sustainable material applications.
基金supported by the grants from University of Macao,China,Nos.MYRG2022-00221-ICMS(to YZ)and MYRG-CRG2022-00011-ICMS(to RW)the Natural Science Foundation of Guangdong Province,No.2023A1515010034(to YZ)。
文摘Ischemic stroke is a secondary cause of mortality worldwide,imposing considerable medical and economic burdens on society.Extracellular vesicles,serving as natural nanocarriers for drug delivery,exhibit excellent biocompatibility in vivo and have significant advantages in the management of ischemic stroke.However,the uncertain distribution and rapid clearance of extracellular vesicles impede their delivery efficiency.By utilizing membrane decoration or by encapsulating therapeutic cargo within extracellular vesicles,their delivery efficacy may be greatly improved.Furthermore,previous studies have indicated that microvesicles,a subset of large-sized extracellular vesicles,can transport mitochondria to neighboring cells,thereby aiding in the restoration of mitochondrial function post-ischemic stroke.Small extracellular vesicles have also demonstrated the capability to transfer mitochondrial components,such as proteins or deoxyribonucleic acid,or their sub-components,for extracellular vesicle-based ischemic stroke therapy.In this review,we undertake a comparative analysis of the isolation techniques employed for extracellular vesicles and present an overview of the current dominant extracellular vesicle modification methodologies.Given the complex facets of treating ischemic stroke,we also delineate various extracellular vesicle modification approaches which are suited to different facets of the treatment process.Moreover,given the burgeoning interest in mitochondrial delivery,we delved into the feasibility and existing research findings on the transportation of mitochondrial fractions or intact mitochondria through small extracellular vesicles and microvesicles to offer a fresh perspective on ischemic stroke therapy.
基金supported in part by Natural Science Foundation of Jiangsu Province under Grant BK20230255Natural Science Foundation of Shandong Province under Grant ZR2023QE281.
文摘The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow controller(CFC)are demanded to ensure the multiterminal DC grid to operates reliably and flexibly.However,since the CFC and the DCCB are all based on fully controlled semiconductor switches(e.g.,insulated gate bipolar transistor,integrated gate commutated thyristor,etc.),their separation configuration in the multiterminal DC grid will lead to unaffordable implementation costs and conduction power losses.To solve these problems,integrated equipment with both current flow control and fault isolation abilities is proposed,which shares the expensive and duplicated components of CFCs and DCCBs among adjacent lines.In addition,the complicated coordination control of CFCs and DCCBs can be avoided by adopting the integrated equipment in themultiterminal DC grid.In order to examine the current flow control and fault isolation abilities of the integrated equipment,the simulation model of a specific meshed four-terminal DC grid is constructed in the PSCAD/EMTDC software.Finally,the comparison between the integrated equipment and the separate solution is presented a specific result or conclusion needs to be added to the abstract.
基金supported by the National Natural Science Foundation of China(52332006)the National Key Research and Development Program of China(2022YFB380600 and 2023YFB3811401)+1 种基金the China Postdoctoral Science Foundation(2022M721850)Southwest United Graduate School Research Program(202302AO370008)。
文摘Quasi-zero-stiffness(QZS)metamaterials have attracted significant interest for application in low-frequency vibration isolation.However,previous work has been limited by the design mechanism of QZS metamaterials,as it is still difficult to achieve a simplified structure suitable for practical engineering applications.Here,we introduce a class of programmable QZS metamaterials and a novel design mechanism that address this long-standing difficulty.The proposed QZS metamaterials are formed by an array of representative unit cells(RUCs)with the expected QZS features,where the QZS features of the RUC are tailored by means of a structural bionic mechanism.In our experiments,we validate the QZS features exhibited by the RUCs,the programmable QZS behavior,and the potential promising applications of these programmable QZS metamaterials in low-frequency vibration isolation.The obtained results could inspire a new class of programmable QZS metamaterials for low-frequency vibration isolation in current and future mechanical and other engineering applications.
基金the support from the National Natural Science Foundation of China(Nos.52279103,52379103)the Natural Science Foundation of Shandong Province(No.ZR2023YQ049)。
文摘Geological analysis,despite being a long-term method for identifying adverse geology in tunnels,has significant limitations due to its reliance on empirical analysis.The quantitative aspects of geochemical anomalies associated with adverse geology provide a novel strategy for addressing these limitations.However,statistical methods for identifying geochemical anomalies are insufficient for tunnel engineering.In contrast,data mining techniques such as machine learning have demonstrated greater efficacy when applied to geological data.Herein,a method for identifying adverse geology using machine learning of geochemical anomalies is proposed.The method was identified geochemical anomalies in tunnel that were not identified by statistical methods.We by employing robust factor analysis and self-organizing maps to reduce the dimensionality of geochemical data and extract the anomaly elements combination(AEC).Using the AEC sample data,we trained an isolation forest model to identify the multi-element anomalies,successfully.We analyzed the adverse geological features based the multi-element anomalies.This study,therefore,extends the traditional approach of geological analysis in tunnels and demonstrates that machine learning is an effective tool for intelligent geological analysis.Correspondingly,the research offers new insights regarding the adverse geology and the prevention of hazards during the construction of tunnels and underground engineering projects.
基金supported by the National Natural Science Foundation of China(82322059)the Chinese Academy of Medical·Sciences Innovation Fund for Medical Sciences(2021-I2M-1-010)+1 种基金the National Key Research and Development Program of China(2021YFC2500500)the National High Level Hospital Clinical Research Funding(2023-GSPRC-19).
文摘Objective Observational studies have shown inconsistent associations of loneliness or social isolation(SI)with ischemic heart disease(IHD),with unknown mediators.Methods Using data from genome-wide association studies of predominantly European ancestry,we performed a bidirectional two-sample Mendelian Randomization(MR)study to estimate causal effects of loneliness(N=487,647)and SI traits on IHD(N=184,305).SI traits included whether individuals lived alone,participated in various types of social activities,and how often they had contact with friends or family(N=459,830 to 461,369).A network MR study was conducted to evaluate the mediating roles of 20 candidate mediators,including metabolic,behavioral and psychological factors.Results Loneliness increased IHD risk(OR=2.129;95%confidence interval[CI]:1.380 to 3.285),mediated by body fat percentage,waist-hip ratio,total cholesterol,and low-density lipoprotein cholesterol.For SI traits,only fewer social activities increased IHD risk(OR=1.815;95%CI:1.189 to 2.772),mediated by hypertension,high-density lipoprotein cholesterol,triglycerides,fasting insulin,and smoking cessation.No reverse causality of IHD with loneliness and SI was found.Conclusion These findings suggested more attention should be paid to individuals who feel lonely and have fewer social activities to prevent IHD,with several mediators as prioritized targets for intervention.
