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
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
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
Strong surface impact will produce strong vibration,which will pose a threat to the safety of nearby buried pipelines and other important lifeline projects.Based on the verified numerical method,a comprehensive numeri...Strong surface impact will produce strong vibration,which will pose a threat to the safety of nearby buried pipelines and other important lifeline projects.Based on the verified numerical method,a comprehensive numerical parameter analysis is conducted on the key influencing factors of the vibration isolation hole(VIH),which include hole diameter,hole net spacing,hole depth,hole number,hole arrangement,and soil parameters.The results indicate that a smaller ratio of net spacing to hole diameter,the deeper the hole,the multi-row hole,the hole adoption of staggered arrangements,and better site soil conditions can enhance the efficiency of the VIH barrier.The average maximum vibration reduction efficiency within the vibration isolation area can reach 42.2%.The vibration safety of adjacent oil pipelines during a dynamic compaction projection was evaluated according to existing standards,and the measurement of the VIH was recommended to reduce excessive vibration.The single-row vibration isolation scheme and three-row staggered arrangement with the same hole parameters are suggested according to different cases.The research findings can serve as a reference for the vibration safety analysis,assessment,and control of adjacent underground facilities under the influence of strong surface impact loads.展开更多
BACKGROUND Frailty has become a significant public health issue.The recent increase in the number of frail older adults has led to increased attention being paid to psycho-logical care services in communities.The soci...BACKGROUND Frailty has become a significant public health issue.The recent increase in the number of frail older adults has led to increased attention being paid to psycho-logical care services in communities.The social isolation of pre-frail older adults can impact their psychological distress.AIM To explore the mediating effect of health literacy between social isolation and psychological distress among communitydwelling older adults with pre-frailty.METHODS This descriptive cross-sectional study was conducted with 254 pre-frail older individuals aged 60 years and over.Social isolation,health literacy,and psycholo-gical distress were comprehensively measured using the Lubben Social Network Scale-6,12-item Short-Form Health Literacy Questionnaire,and the Kessler Psy-chological Distress Scale-10.Data were evaluated using the SPSS 27.0 package program and the PROCESS macro tool.Descriptive statistical analyses,correlation analyses,and bootstrap mediation tests were used to assess associations between the variables.RESULTS The results showed that social isolation had an effect on health literacy among pre-frail older adults(β=0.240,P<0.001),social isolation impact on psycho-logical distress pre-frail older adults(β=-0.415,P<0.001);health literacy was identified effect on psychological distress among pre-frail older persons(β=-0.307,P<0.001).Health literacy partially mediated the relationship between social isolation and psychological distress among community-dwelling older adults with pre-frailty,with a mediation effect of-0.074,accounting for 17.83%of the total effect.展开更多
This work discusses the strain and acceleration suppression of a flexible beam subjected to different supports analytically.As classical protection,the beam is mounted on a vertical linear spring together with a linea...This work discusses the strain and acceleration suppression of a flexible beam subjected to different supports analytically.As classical protection,the beam is mounted on a vertical linear spring together with a linear damper in parallel.This is called linear isolation.To enhance isolation performance,nonlinearity is employed in the boundary.In addition,quasi-zero isolation is established based on the non-linearly enhanced one by adjusting the installation length of the horizontal spring.To discuss their performance fully and fairly,the amplitude,the acceleration,the potential energy of the beam,the input work of the excitation,the dissipation work of the beam,and the dynamics stress along the beam are investigated based on the same parameters.The comparison shows that all these isolations can protect the beam with high efficiency,even when the basement excitation is tiny.Although the linear isolation and the nonlinearly enhanced one will arouse two resonance peaks on both sides of the primary resonance of the beam without isolation,the maximum amplitudes of them are reduced a lot.But for the low frequency excitation,the quasi-zero isolation has the best performance as it drives the primary resonance to the high frequency region.The simulation shows that the beam needs a relatively soft isolation to avoid the damage caused by the shock vibration,including the quasi-zero one.In general,the quasi-zero isolation shows the best performance.The nonlinearly enhanced one is the suboptimal choice.The present work shows the capacities of three isolations for a flexible beam by the steady-state response and the shock vibration.It provides design suggestions for the isolation of flexible beams.展开更多
The biological species concept defines species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups(Mayr,1942).Reproductive isolation,whether p...The biological species concept defines species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups(Mayr,1942).Reproductive isolation,whether prezygotic or postzygotic,plays a central role in maintaining species boundaries.However,hybridization between closely related taxa can challenge these boundaries and provide insight into speciation,gene flow,and evolutionary processes(Coyne and Orr,2004).展开更多
This paper reports on the composition of fungal communities occurring on diseased tissues of Catharanthus roseus,which differed between organs.In total,ten different filamentous fungi were isolated,and the percentage ...This paper reports on the composition of fungal communities occurring on diseased tissues of Catharanthus roseus,which differed between organs.In total,ten different filamentous fungi were isolated,and the percentage of isolation varied significantly among the organs.Botrytis cinerea was the most prevalent fungus found on the plant’s aboveground parts,with a frequency exceeding 50%.On twigs,the occurrence rate was 95.6%.It was isolated from leaves with a frequency of 88%,followed by Aspergillus niger(71.66%),Alternaria alternata(67.33%),Cladosporium herbarum(61%),Fusarium oxysporum(50.66%),Epicoccum nigrum(57.66%),Curvularia lunata(49.66%),Trichoderma harzianum(40%),and Penicillium sp.(27%).Whereas,Fusarium genus was more represented and six species were recorded:F.subglutinans(26%),F.chlamydosporium(20%),F.vertillioides(15.66%),F.solani(10%),F.oxysporum and F.nivale.Results highlighted dissimilar distribution of Fusarium species was noted on Catharanthus tissues on which F.subglutinas,F.chlamydosporium and F.oxysporum coexist on leaves and roots while F.solani was retrieved from leaves against F.nivale from roots.The floral buds and pods harbored opportunist fungi such as B.cinerea,Alternaria alternata and E.nigrum.On roots,Aspergillus,Penicillium and Fusarium were the main genera occurring with the frequencies of 26%(F.chlamydosporium),40%(F.nivale),72.33%(A.niger),47.66%(A.flavus)and 37.66%(A.fumigatus).But no fungal species were detected on seeds of Catharanthus roseus.This is the first study to describe and enumerate the fungal complex associated with various symptoms on the aerial parts of Catharanthus roseus.展开更多
Habitat fragmentation dramatically reshapes species richness and community composition.However,most estimates ofβ-diversity rely on incidence-based metrics,which consider only species presence/absence.Here,we introdu...Habitat fragmentation dramatically reshapes species richness and community composition.However,most estimates ofβ-diversity rely on incidence-based metrics,which consider only species presence/absence.Here,we introduce a novel framework that explicitly incorporates species abundance and intraspecifictrait variation(ITV)into the quantificationof taxonomic,functional,and phylogeneticβ-diversity,allowing a more nuanced understanding of community differentiation.To demonstrate the utility of this framework,we quantifiedthe effects of island area and isolation onβ-diversity across plant communities in China's Thousand Island Lake.Abundance-weighted taxonomic multiple-site/pairwiseβ-diversity showed substantially higher nestedness and stronger nestedness-area relationship than incidence-based metrics,indicating that species-poor communities are not only subsets of richer ones but share similar abundance hierarchies,highlighting strong environmental filteringand hierarchical species sorting.We also found that the turnover component was less sensitive to isolation,suggesting limited dispersal effects.Incidence-based functional and phylogenetic distances increased with differences in island area,but these associations weakened or disappeared in abundance-weighted measures,suggesting stronger environmental filteringand functional/phylogenetic clustering among larger islands.Only abundance-weighted standardized effect sizes increased with island area differences.Additionally,ITV further amplifiedfunctional nestedness and buffered the influenceof isolation on turnover,emphasizing its role in mitigating dispersal limitations.By jointly considering abundance and ITV,two often-overlooked but critical dimensions,this study advances our understanding of how fragmentation shapesβ-diversity.These findingshighlight the importance of integrating abundanceweighted and trait-based metrics into conservation strategies to better detect functionally important species,prioritize larger habitat patches,and design biodiversity monitoring that captures withinspecies variation.展开更多
主题语境:志愿服务篇幅:337词建议用时:6分钟。1 Life after retirement can be isolating,especially for older men who built their identities around their jobs.Jim Isenberg,in his late 70s,experienced this first-hand.He had...主题语境:志愿服务篇幅:337词建议用时:6分钟。1 Life after retirement can be isolating,especially for older men who built their identities around their jobs.Jim Isenberg,in his late 70s,experienced this first-hand.He had a varied career in transportation and family services in White Plains,New York.When he became a grandfather,he wanted to connect with other men at the same stage of life,but found few options for grandfathers.So,he and his friend Frank Williams founded Grandpas United in 2018.展开更多
Acoustic communication signals are important for species recognition and mate attraction across numerous taxa.For instance,most of thethousands of species of frogs have a species-specifc advertisement call that female...Acoustic communication signals are important for species recognition and mate attraction across numerous taxa.For instance,most of thethousands of species of frogs have a species-specifc advertisement call that females use to localize and discriminate among potential mates.Thus,the acoustic structure of the advertisement call is critical for reproductive success.The acoustic structure of calls will generally divergeover evolutionary time and can be infuenced by the calls of sympatric species.While many studies have shown the infuence of geographyon contemporary call variation in populations of frogs,no study has compared the acoustic structure of frog calls across many species to askwhether we can detect an infuence of divergence time and overall geographic overlap on the differences in acoustic structure of species-typicalcalls that we observe now.To this end,we compared acoustic features of the calls of 225 species of frogs within 4 families.Furthermore,weused a behavioral assay from 1 species of frog to determine which acoustic features to prioritize in our large-scale analyses.We found evidencethat both phylogeny(time)and geography(place)relate to advertisement call acoustics albeit with large variation in these relationships acrossthe 4 families in the analysis.Overall,these results suggest that,despite the many ecological and evolutionary forces that infuence call structure,the broad forces of time and place can shape aspects of advertisement call acoustics.展开更多
Exosomes,nanosized extracellular vesicles(30-150 nm),play a crucial role in intercellular communication and are promising biomarkers and therapeutic agents in oncology,neurodegenerative disorders,and immunotherapy.How...Exosomes,nanosized extracellular vesicles(30-150 nm),play a crucial role in intercellular communication and are promising biomarkers and therapeutic agents in oncology,neurodegenerative disorders,and immunotherapy.However,their widespread clinical adoption is constrained by challenges in scalable production,efficient purification,and regulatory standardization.This review critically evaluates recent advancements in exosome bioprocessing,including cell source optimization,culture refinement,and next-generation isolation technologies such as microfluidic microarrays and EXODUS systems.Additionally,we address the limitations of current exosome standardization efforts and propose harmonized protocols to enhance reproducibility.Future research should focus on integrating scalable bioreactor-based systems and artificial intelligence-driven quality control frameworks to accelerate exosome applications in precision medicine and regenerative therapy.展开更多
Staphylococcus aureus (S. aureus) is a bacterial pathogen for humans and animals. These bacteria can resist against many antibiotics and this resistance constitute an alarming worldwide human health threat due to the ...Staphylococcus aureus (S. aureus) is a bacterial pathogen for humans and animals. These bacteria can resist against many antibiotics and this resistance constitute an alarming worldwide human health threat due to the morbidity and mortality. Phage therapy is one of the alternative treatments. The aim of this study was to isolate and characterize lytic phages of S. aureus from different wastewater sources in Bobo-Dioulasso, Burkina Faso. Eight strains of S. aureus were isolated from different clinical samples and were used to isolate phages. The isolation and host range of phages were done by the spot test. Phages were purified by the double-layer method. Similar phages after the determination of the host range were characterized using restriction enzymes. A total of 27 phages were obtained after isolation and purification. Nine of the 27 isolates reported a broad host range (≥67%). The results of enzymatic digestion allowed to consider that all phage isolates that presented the same host range and the same genetic fingerprint are the same phage strain;whereas phages that presented the same host range and different genetic fingerprints are different phage strains. Thus, a total of 15 distinct phages isolates specific to S. aureus were characterized. This study highlighted the abundance and lytic capacity of phages isolated from wastewater from Bobo-Dioulasso’s environment against clinical strains of S. aureus. The lytic capacity of these Staphyphages could be an effective alternative tool to combat bacteria multi-resistance.展开更多
Achieving vibration isolation,lightweight design,and reusability under impact remains a critical challenge for thin-walled structures.When the goat skull is subjected to impact,both the outer wall of the sinus and the...Achieving vibration isolation,lightweight design,and reusability under impact remains a critical challenge for thin-walled structures.When the goat skull is subjected to impact,both the outer wall of the sinus and the internal bony struts deform simultaneously to absorb energy and protect intracranial tissues.Inspired by this mechanism,we designed the goat sinus-inspired bio mimetic(GSIB) structure by mimicking the outer wall of the sinus and the internal pillar-like support system.The structure consists of dual coupling beams,including a set of inclined cantilever beams representing the sinus outer wall and vertical support beams simulating the internal bony struts.The GSIB structure was fabricated using Selective Laser Sintering(SLS) 3D printing technology,and its mechanical properties were investigated through a combination of quasi-static compression tests,vibration tests,impact tests,and finite element simulations.Under compressive loading,the inclined cantilever beams buckle to introduce a negative stiffness effect,while the vertical supports enhance overall stiffness.Leveraging the coupling effect between these two components,the structure achieves a long-stroke constant-force response,thereby delivering superior performance in energy absorption and vibration isolation.Additionally,the special deformation mode of the GSIB structure enables it to be reused under impact conditions.It is noteworthy that,compared to the negative stiffness(NS) structure with the same dimensions for repeated buffering proposed in previous studies,the GSIB structure demonstrates an energy absorption capacity reaching 214.3% of that of the NS structure,a reduction in isolation frequency to 58.5%,and an impact acceleration that is only 66.31% of that of the NS structure.Additionally,the plateau stress of the proposed structure increases to 246.07% of that of the NS structure.This novel artificial structure provides a new design strategy for achieving superior energy absorption and impact resistance under repeated impact conditions.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.
基金National Natural Science Foundation of China under Grant Nos.52078386 and 52308496SINOMACH Youth Science and Technology Fund under Grant No.QNJJ-PY-2022-02+2 种基金Young Elite Scientists Sponsorship Program under Grant No.BYESS2023432Fund of State Key Laboratory of Precision Blasting and Hubei Key Laboratory of Blasting Engineering,Jianghan University under Grant No.PBSKL2023A9Fund of China Railway Construction Group Co.,Ltd.under Grant No.LX19-04b。
文摘Strong surface impact will produce strong vibration,which will pose a threat to the safety of nearby buried pipelines and other important lifeline projects.Based on the verified numerical method,a comprehensive numerical parameter analysis is conducted on the key influencing factors of the vibration isolation hole(VIH),which include hole diameter,hole net spacing,hole depth,hole number,hole arrangement,and soil parameters.The results indicate that a smaller ratio of net spacing to hole diameter,the deeper the hole,the multi-row hole,the hole adoption of staggered arrangements,and better site soil conditions can enhance the efficiency of the VIH barrier.The average maximum vibration reduction efficiency within the vibration isolation area can reach 42.2%.The vibration safety of adjacent oil pipelines during a dynamic compaction projection was evaluated according to existing standards,and the measurement of the VIH was recommended to reduce excessive vibration.The single-row vibration isolation scheme and three-row staggered arrangement with the same hole parameters are suggested according to different cases.The research findings can serve as a reference for the vibration safety analysis,assessment,and control of adjacent underground facilities under the influence of strong surface impact loads.
基金Supported by the Scientific Research Fund of Zhejiang Provincial Education Department,No.Y202351104and Huzhou Science and Technology Plan Project,No.2023GZ67。
文摘BACKGROUND Frailty has become a significant public health issue.The recent increase in the number of frail older adults has led to increased attention being paid to psycho-logical care services in communities.The social isolation of pre-frail older adults can impact their psychological distress.AIM To explore the mediating effect of health literacy between social isolation and psychological distress among communitydwelling older adults with pre-frailty.METHODS This descriptive cross-sectional study was conducted with 254 pre-frail older individuals aged 60 years and over.Social isolation,health literacy,and psycholo-gical distress were comprehensively measured using the Lubben Social Network Scale-6,12-item Short-Form Health Literacy Questionnaire,and the Kessler Psy-chological Distress Scale-10.Data were evaluated using the SPSS 27.0 package program and the PROCESS macro tool.Descriptive statistical analyses,correlation analyses,and bootstrap mediation tests were used to assess associations between the variables.RESULTS The results showed that social isolation had an effect on health literacy among pre-frail older adults(β=0.240,P<0.001),social isolation impact on psycho-logical distress pre-frail older adults(β=-0.415,P<0.001);health literacy was identified effect on psychological distress among pre-frail older persons(β=-0.307,P<0.001).Health literacy partially mediated the relationship between social isolation and psychological distress among community-dwelling older adults with pre-frailty,with a mediation effect of-0.074,accounting for 17.83%of the total effect.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.12002195 and 12372015)the National Science Fund for Distinguished Young Scholars(Grant No.12025204)the Program of Shanghai Municipal Education Commission(Grant No.2019-01-07-00-09-E00018).
文摘This work discusses the strain and acceleration suppression of a flexible beam subjected to different supports analytically.As classical protection,the beam is mounted on a vertical linear spring together with a linear damper in parallel.This is called linear isolation.To enhance isolation performance,nonlinearity is employed in the boundary.In addition,quasi-zero isolation is established based on the non-linearly enhanced one by adjusting the installation length of the horizontal spring.To discuss their performance fully and fairly,the amplitude,the acceleration,the potential energy of the beam,the input work of the excitation,the dissipation work of the beam,and the dynamics stress along the beam are investigated based on the same parameters.The comparison shows that all these isolations can protect the beam with high efficiency,even when the basement excitation is tiny.Although the linear isolation and the nonlinearly enhanced one will arouse two resonance peaks on both sides of the primary resonance of the beam without isolation,the maximum amplitudes of them are reduced a lot.But for the low frequency excitation,the quasi-zero isolation has the best performance as it drives the primary resonance to the high frequency region.The simulation shows that the beam needs a relatively soft isolation to avoid the damage caused by the shock vibration,including the quasi-zero one.In general,the quasi-zero isolation shows the best performance.The nonlinearly enhanced one is the suboptimal choice.The present work shows the capacities of three isolations for a flexible beam by the steady-state response and the shock vibration.It provides design suggestions for the isolation of flexible beams.
基金supported by the National Natural Science Foundation of China(No.32161143024,31970405)Iran National Science Foundation,Iran-China(INSF-NSFC)joint project(No.4002006).
文摘The biological species concept defines species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups(Mayr,1942).Reproductive isolation,whether prezygotic or postzygotic,plays a central role in maintaining species boundaries.However,hybridization between closely related taxa can challenge these boundaries and provide insight into speciation,gene flow,and evolutionary processes(Coyne and Orr,2004).
文摘This paper reports on the composition of fungal communities occurring on diseased tissues of Catharanthus roseus,which differed between organs.In total,ten different filamentous fungi were isolated,and the percentage of isolation varied significantly among the organs.Botrytis cinerea was the most prevalent fungus found on the plant’s aboveground parts,with a frequency exceeding 50%.On twigs,the occurrence rate was 95.6%.It was isolated from leaves with a frequency of 88%,followed by Aspergillus niger(71.66%),Alternaria alternata(67.33%),Cladosporium herbarum(61%),Fusarium oxysporum(50.66%),Epicoccum nigrum(57.66%),Curvularia lunata(49.66%),Trichoderma harzianum(40%),and Penicillium sp.(27%).Whereas,Fusarium genus was more represented and six species were recorded:F.subglutinans(26%),F.chlamydosporium(20%),F.vertillioides(15.66%),F.solani(10%),F.oxysporum and F.nivale.Results highlighted dissimilar distribution of Fusarium species was noted on Catharanthus tissues on which F.subglutinas,F.chlamydosporium and F.oxysporum coexist on leaves and roots while F.solani was retrieved from leaves against F.nivale from roots.The floral buds and pods harbored opportunist fungi such as B.cinerea,Alternaria alternata and E.nigrum.On roots,Aspergillus,Penicillium and Fusarium were the main genera occurring with the frequencies of 26%(F.chlamydosporium),40%(F.nivale),72.33%(A.niger),47.66%(A.flavus)and 37.66%(A.fumigatus).But no fungal species were detected on seeds of Catharanthus roseus.This is the first study to describe and enumerate the fungal complex associated with various symptoms on the aerial parts of Catharanthus roseus.
基金supported by the National Natural Science Foundation of China(grant no.32371603,31901211 and 31930073).
文摘Habitat fragmentation dramatically reshapes species richness and community composition.However,most estimates ofβ-diversity rely on incidence-based metrics,which consider only species presence/absence.Here,we introduce a novel framework that explicitly incorporates species abundance and intraspecifictrait variation(ITV)into the quantificationof taxonomic,functional,and phylogeneticβ-diversity,allowing a more nuanced understanding of community differentiation.To demonstrate the utility of this framework,we quantifiedthe effects of island area and isolation onβ-diversity across plant communities in China's Thousand Island Lake.Abundance-weighted taxonomic multiple-site/pairwiseβ-diversity showed substantially higher nestedness and stronger nestedness-area relationship than incidence-based metrics,indicating that species-poor communities are not only subsets of richer ones but share similar abundance hierarchies,highlighting strong environmental filteringand hierarchical species sorting.We also found that the turnover component was less sensitive to isolation,suggesting limited dispersal effects.Incidence-based functional and phylogenetic distances increased with differences in island area,but these associations weakened or disappeared in abundance-weighted measures,suggesting stronger environmental filteringand functional/phylogenetic clustering among larger islands.Only abundance-weighted standardized effect sizes increased with island area differences.Additionally,ITV further amplifiedfunctional nestedness and buffered the influenceof isolation on turnover,emphasizing its role in mitigating dispersal limitations.By jointly considering abundance and ITV,two often-overlooked but critical dimensions,this study advances our understanding of how fragmentation shapesβ-diversity.These findingshighlight the importance of integrating abundanceweighted and trait-based metrics into conservation strategies to better detect functionally important species,prioritize larger habitat patches,and design biodiversity monitoring that captures withinspecies variation.
文摘主题语境:志愿服务篇幅:337词建议用时:6分钟。1 Life after retirement can be isolating,especially for older men who built their identities around their jobs.Jim Isenberg,in his late 70s,experienced this first-hand.He had a varied career in transportation and family services in White Plains,New York.When he became a grandfather,he wanted to connect with other men at the same stage of life,but found few options for grandfathers.So,he and his friend Frank Williams founded Grandpas United in 2018.
基金funded through a grant from the NationalScience Foundation(IOS-1914646)the SmithsonianInstitute Postdoctoral Fellowship program.
文摘Acoustic communication signals are important for species recognition and mate attraction across numerous taxa.For instance,most of thethousands of species of frogs have a species-specifc advertisement call that females use to localize and discriminate among potential mates.Thus,the acoustic structure of the advertisement call is critical for reproductive success.The acoustic structure of calls will generally divergeover evolutionary time and can be infuenced by the calls of sympatric species.While many studies have shown the infuence of geographyon contemporary call variation in populations of frogs,no study has compared the acoustic structure of frog calls across many species to askwhether we can detect an infuence of divergence time and overall geographic overlap on the differences in acoustic structure of species-typicalcalls that we observe now.To this end,we compared acoustic features of the calls of 225 species of frogs within 4 families.Furthermore,weused a behavioral assay from 1 species of frog to determine which acoustic features to prioritize in our large-scale analyses.We found evidencethat both phylogeny(time)and geography(place)relate to advertisement call acoustics albeit with large variation in these relationships acrossthe 4 families in the analysis.Overall,these results suggest that,despite the many ecological and evolutionary forces that infuence call structure,the broad forces of time and place can shape aspects of advertisement call acoustics.
基金supported by the Shanghai Clinical Research Center of Plastic and Reconstructive Surgery,funded by the Science and Technology Commission of Shanghai Municipality(grant no.22MC1940300)the Shanghai Key Research Center—Shanghai Research Center for Plastic Surgery(grant no.2023ZZ02023).
文摘Exosomes,nanosized extracellular vesicles(30-150 nm),play a crucial role in intercellular communication and are promising biomarkers and therapeutic agents in oncology,neurodegenerative disorders,and immunotherapy.However,their widespread clinical adoption is constrained by challenges in scalable production,efficient purification,and regulatory standardization.This review critically evaluates recent advancements in exosome bioprocessing,including cell source optimization,culture refinement,and next-generation isolation technologies such as microfluidic microarrays and EXODUS systems.Additionally,we address the limitations of current exosome standardization efforts and propose harmonized protocols to enhance reproducibility.Future research should focus on integrating scalable bioreactor-based systems and artificial intelligence-driven quality control frameworks to accelerate exosome applications in precision medicine and regenerative therapy.
文摘Staphylococcus aureus (S. aureus) is a bacterial pathogen for humans and animals. These bacteria can resist against many antibiotics and this resistance constitute an alarming worldwide human health threat due to the morbidity and mortality. Phage therapy is one of the alternative treatments. The aim of this study was to isolate and characterize lytic phages of S. aureus from different wastewater sources in Bobo-Dioulasso, Burkina Faso. Eight strains of S. aureus were isolated from different clinical samples and were used to isolate phages. The isolation and host range of phages were done by the spot test. Phages were purified by the double-layer method. Similar phages after the determination of the host range were characterized using restriction enzymes. A total of 27 phages were obtained after isolation and purification. Nine of the 27 isolates reported a broad host range (≥67%). The results of enzymatic digestion allowed to consider that all phage isolates that presented the same host range and the same genetic fingerprint are the same phage strain;whereas phages that presented the same host range and different genetic fingerprints are different phage strains. Thus, a total of 15 distinct phages isolates specific to S. aureus were characterized. This study highlighted the abundance and lytic capacity of phages isolated from wastewater from Bobo-Dioulasso’s environment against clinical strains of S. aureus. The lytic capacity of these Staphyphages could be an effective alternative tool to combat bacteria multi-resistance.
文摘Achieving vibration isolation,lightweight design,and reusability under impact remains a critical challenge for thin-walled structures.When the goat skull is subjected to impact,both the outer wall of the sinus and the internal bony struts deform simultaneously to absorb energy and protect intracranial tissues.Inspired by this mechanism,we designed the goat sinus-inspired bio mimetic(GSIB) structure by mimicking the outer wall of the sinus and the internal pillar-like support system.The structure consists of dual coupling beams,including a set of inclined cantilever beams representing the sinus outer wall and vertical support beams simulating the internal bony struts.The GSIB structure was fabricated using Selective Laser Sintering(SLS) 3D printing technology,and its mechanical properties were investigated through a combination of quasi-static compression tests,vibration tests,impact tests,and finite element simulations.Under compressive loading,the inclined cantilever beams buckle to introduce a negative stiffness effect,while the vertical supports enhance overall stiffness.Leveraging the coupling effect between these two components,the structure achieves a long-stroke constant-force response,thereby delivering superior performance in energy absorption and vibration isolation.Additionally,the special deformation mode of the GSIB structure enables it to be reused under impact conditions.It is noteworthy that,compared to the negative stiffness(NS) structure with the same dimensions for repeated buffering proposed in previous studies,the GSIB structure demonstrates an energy absorption capacity reaching 214.3% of that of the NS structure,a reduction in isolation frequency to 58.5%,and an impact acceleration that is only 66.31% of that of the NS structure.Additionally,the plateau stress of the proposed structure increases to 246.07% of that of the NS structure.This novel artificial structure provides a new design strategy for achieving superior energy absorption and impact resistance under repeated impact conditions.
