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
Gate drivers for high-voltage silicon carbide(SiC)converters require a reliable power supply with strong isolation and compact size.However,existing gate driver power supplies(GDPS)with the transformer structure make ...Gate drivers for high-voltage silicon carbide(SiC)converters require a reliable power supply with strong isolation and compact size.However,existing gate driver power supplies(GDPS)with the transformer structure make it difficult to enhance the isolation performance while keeping the small coupling capacitance and volume.This paper firstly presents a novel wireless GDPS with an improved Class-E inverter for high-voltage energy harvesting applications.The proposed design requires only one switch and reduces the input inductor significantly.Meanwhile,it solves the issue of harmful surge currents and maintains a zero-voltage-switching state when the load changes.Finally,a compact wireless GDPS prototype is developed and the insulation characteristics are studied.Results demonstrate that the proposed design achieves isolation voltage up to 17.7 kV with the smallest size volume and extra-low coupling capacitance of 1.83 pF.展开更多
Mesenchymal stem cells are highly regarded for their potential in tissue repair and regenerative medicine due to their multipotency and self-renewal abilities.Recently,mesenchymal stem cells have been redefined as“me...Mesenchymal stem cells are highly regarded for their potential in tissue repair and regenerative medicine due to their multipotency and self-renewal abilities.Recently,mesenchymal stem cells have been redefined as“medical signaling cells,”with their primary biological effects mediated through exosome secretion.These exosomes,which contain lipids,proteins,RNA,and metabolites,are crucial in regulating various biological processes and enhancing regenerative therapies.Exosomes replicate the effects of their parent cells while offering benefits such as reduced side effects,low immunogenicity,excellent biocompatibility,and high drug-loading capacity.Dental stem cells,including those from apical papilla,gingiva,dental pulp,and other sources,are key contributors to exosome-mediated regenerative effects,such as tumor cell apoptosis,neuroprotection,angiogenesis,osteogenesis,and immune modulation.Despite their promise,clinical application of exosomes is limited by challenges in isolation techniques.Current methods face issues of complexity,inefficiency,and insufficient purity,hindering detailed analysis.Recent advancements,such as micro-electromechanical systems,alternating current electroosmosis,and serum-free three-dimensional cell cultures,have improved exosome isolation efficacy.This review synthesizes nearly 200 studies on dental stem cell-derived exosomes,highlighting their potential in treating a wide range of conditions,including periodontal diseases,cancer,neurodegenerative disorders,diabetes,and more.Optimized isolation methods offer a path forward for overcoming current limitations and advancing the clinical use of exosome-based therapies.展开更多
As industrialization and informatization in China deeply integrate and the Internet of Things rapidly develops,industrial control systems are facing increasingly severe information security challenges.The industrial c...As industrialization and informatization in China deeply integrate and the Internet of Things rapidly develops,industrial control systems are facing increasingly severe information security challenges.The industrial control system of the gas extraction plant is characterized by numerous points and centralized operations,with a strong reliance on the system and stringent real-time requirements.展开更多
[Objectives]This study aimed to investigate the pathogenicity,growth characteristics and drug resistance of Streptococcus suis type 2.[Methods]Bacterial isolation and identification,biochemical experiments,determinati...[Objectives]This study aimed to investigate the pathogenicity,growth characteristics and drug resistance of Streptococcus suis type 2.[Methods]Bacterial isolation and identification,biochemical experiments,determination of growth curve and correlation curve between OD 600 values and viable counts,drug susceptibility tests,pathogenicity analysis,and histopathological observations were carried out.[Results]The Streptococcus strain isolated from infected pigs was identified as Streptococcus suis type 2,which was named TA01 strain.TA01 strain reached the growth peak at 6-8 h post-incubation,and viable counts gradually declined after 8 h of incubation.The correlation equation between OD 600 values and viable counts is y=24.659 x-1.076 1,R^2=0.996 7.TA01 strain was sensitive to penicillin,erythromycin,florfenicol and oxacillin,and resistant to ciprofloxacin,polymyxin B and clindamycin.According to the results of pathogenicity analysis,all the mice in 3.6×10^9 cfu/mouse group died within 48,and these dead mice exhibited acute pyaemia septica.Based on the Reed-Muench formula,it was calculated that LD 50 of TA01 strain was 1.137×10^8 cfu/mouse.Pathological examination showed obvious blue-stained bacteria clusters,accompanied by neutrophil infiltration.[Conclusions]TA01 strain was a virulent strain of Streptococcus suis type 2.Compared with Streptococcus strains which were isolated and reported in China,TA01 strain exhibited strong virulence and rapid proliferation.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
This research aims to address the challenges of fault detection and isolation(FDI)in digital grids,focusing on improving the reliability and stability of power systems.Traditional fault detection techniques,such as ru...This research aims to address the challenges of fault detection and isolation(FDI)in digital grids,focusing on improving the reliability and stability of power systems.Traditional fault detection techniques,such as rule-based fuzzy systems and conventional FDI methods,often struggle with the dynamic nature of modern grids,resulting in delays and inaccuracies in fault classification.To overcome these limitations,this study introduces a Hybrid NeuroFuzzy Fault Detection Model that combines the adaptive learning capabilities of neural networks with the reasoning strength of fuzzy logic.The model’s performance was evaluated through extensive simulations on the IEEE 33-bus test system,considering various fault scenarios,including line-to-ground faults(LGF),three-phase short circuits(3PSC),and harmonic distortions(HD).The quantitative results show that the model achieves 97.2%accuracy,a false negative rate(FNR)of 1.9%,and a false positive rate(FPR)of 2.3%,demonstrating its high precision in fault diagnosis.The qualitative analysis further highlights the model’s adaptability and its potential for seamless integration into smart grids,micro grids,and renewable energy systems.By dynamically refining fuzzy inference rules,the model enhances fault detection efficiency without compromising computational feasibility.These findings contribute to the development of more resilient and adaptive fault management systems,paving the way for advanced smart grid technologies.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
Constructing a statistical model that best fits the background is a key step in geochemical anomaly identification. But the model is hard to be constructed in situations where the sample population has unknown and/or ...Constructing a statistical model that best fits the background is a key step in geochemical anomaly identification. But the model is hard to be constructed in situations where the sample population has unknown and/or complex distribution. Isolation forest is an outlier detection approach that explicitly isolates anomaly samples rather than models the population distribution. It can extract multivariate anomalies from huge-sized high-dimensional data with unknown population distribution. For this reason,we tentatively applied the method to identify multivariate anomalies from the stream sediment survey data of the Lalingzaohuo district,an area with a complex geological setting,in Qinghai Province in China. The performance of the isolation forest algorithm in anomaly identification was compared with that of a continuous restricted Boltzmann machine. The results show that the isolation forest model performs superiorly to the continuous restricted Boltzmann machine in multivariate anomaly identification in terms of receiver operating characteristic curve,area under the curve,and data-processing efficiency. The anomalies identified by the isolation forest model occupy 19% of the study area and contain 82% of the known mineral deposits,whereas the anomalies identified by the continuous restricted Boltzmann machine occupy 35% of the study area and contain 88% of the known mineral deposits. It takes 4. 07 and 279. 36 seconds respectively handling the dataset using the two models. Therefore,isolation forest is a useful anomaly detection method that can quickly extract multivariate anomalies from geochemical exploration data.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
The present research work was carried out to isolate and identify Newcastle disease virus (NDV) by using haemagglutination inhibition (HI) test and HA-HI virus isolation, embryonated eggs (EE) and chicken embryo fibro...The present research work was carried out to isolate and identify Newcastle disease virus (NDV) by using haemagglutination inhibition (HI) test and HA-HI virus isolation, embryonated eggs (EE) and chicken embryo fibroblasts (CEF). A total of 95 clinical (blood, tracheal and cloacal swabs) and post-mortem (brain, lung, colon and spleen) samples were collected from chickens of field outbreaks of suspected Newcastle disease virus (NDV). The HI and HA-HI were employed to detect NDV in tissue homogenates of all the clinical and post-mortem samples as well as laboratory samples (AF and ICF). Among the four different types of post-mortem samples, virus isolation rate was found to be low in body organs. In CEF cell culture system, the rate of virus isolation from all the aforesaid samples was found to be at 100% with the exception of serum samples;while in tracheal and cloacal swabs, it was at 90%;while in serum, it was at 10%, in all clinical cases. The isolation rate of NDV was higher in CEF culture system (66.7%) compared to that of avian embryos (33.3%). Samples were inoculated and the allantoic fluid (AF) of the dead embryos and the infected culture fluid (ICF) of the CEF were harvested at 24 to 96 hours of the post-infection, respectively, which revealed that the virulent strain of NDV is highly prevalent in the region. The prevalence of NDV was established at 1.1%, 2.1% and 4.2% using HA-HI, EE, and CEF methods. Rapid detection and identification of the virus are crucial for the effective control of the disease as conventional diagnostic methods such as virus isolation on embryonated eggs followed by serological identification in haemagglutination-inhibition test are laborious and time-consuming. The speed of the diagnosis can be considerably increased by using methods based on molecular biology, e.g. reverse transcription—polymerase chain reaction. However, the genetic variability of APMV-1 isolates should be considered carefully as the potential cause for false negative results of genetic-based laboratory tests.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
Traditional linear vibration isolators struggle to combine high load-bearing capacity with low-frequency vibration isolation, whereas nonlinear metastructure isolators can effectively fulfill both functions. This pape...Traditional linear vibration isolators struggle to combine high load-bearing capacity with low-frequency vibration isolation, whereas nonlinear metastructure isolators can effectively fulfill both functions. This paper draws inspiration from the Quasi-Zero Stiffness (QZS) characteristics resulting from the buckling deformation of beams, and proposes a gear-based QZS structure by arranging beams in a circular array. We investigated the static mechanical behavior under different structural parameters, loading angles, and gear combinations through experiments and simulations, and demonstrated the mechanical performances could be effectively programmed. Subsequent vibration isolation tests on the double gears prove superior vibration isolation performance at low frequency while maintaining high load-bearing capacities. Additionally, a key contribution of our work is the development of a mathematical model to characterize the buckling behavior of the unit beam within the gear structure, with its accuracy validated through finite element analysis and experimental results. The gear’s modulus, number of teeth, and pressure angle are selected according to standard series, allowing the gear can be seamlessly integrated into existing mechanical systems in critical fields such as aerospace, military, and etc.展开更多
Traffic-induced ground vibrations cause significant problems for residents and nearby structures.Reducing the effect of these vibrations on the neighboring environment is a key challenge,particularly in urban areas.Th...Traffic-induced ground vibrations cause significant problems for residents and nearby structures.Reducing the effect of these vibrations on the neighboring environment is a key challenge,particularly in urban areas.This study presents both numerical and experimental investigations of the performance of mass scatters for screening ground vibrations.A three-dimensional numerical model is validated and extended to conduct a comparative study on the efficiency of three geotechnical methods of isolation.These methods include trench barriers,waveimpeding blocks(WIBs),and mass scatters.The results showed that mass scatters represent an efficient way of scattering ground vibrations,and their efficiency is mainly related to the weights of mass scatters and their natural frequency,which control the dynamic soil response in the frequency domain.Rigid trench barriers are less effective than soft ones,and their efficiency is more pronounced regarding the WIB.Soft barriers with a depth of an order of half of the wavelength can decrease the vibration levels by up to 50%,which is comparable to the performance of enormous mass scatters.The dimensions of WIBs must be chosen according to the wavelength of incident waves and the cutoff frequency of the topsoil layer.Considering the significant wavelength of traffic-induced vibration,the use of trench barriers or WIBs becomes impractical and expensive;therefore,mass scatters appear to be an efficient and practical solution.展开更多
Panax notoginseng is a traditional Chinese medicine containing various constituents,including the saponins,polysaccharides,polyacetylenes,amino acids,etc.It has beneficial functions,such as the anti-inflammatory,antit...Panax notoginseng is a traditional Chinese medicine containing various constituents,including the saponins,polysaccharides,polyacetylenes,amino acids,etc.It has beneficial functions,such as the anti-inflammatory,antitumor,hepatoprotective,and anti-aging effects.Among these,P.notoginseng polysaccharides(PNPs)have been exploited because of their extensive pharmacological effects,being ranked as one of the current research hotspots,especially for the functional foods and medical practice.In this review,the literature related to PNPs in the past 20 years was surveyed and analyzed using both the China National Knowledge Infrastructure(CNKI)and Web of Science(WOS)databases.The visualization diagram shows that current studies on PNPs mainly focus on the antioxidant and immunomodulatory activities and structural characterization.In addition,the extraction,separation,purification,chemical analysis,structural characteristics,bioactivities,and applications of PNPs are outlined,in detail,aimed to provide valuable information for the further study,development,and utilization regarding PNPs.展开更多
BACKGROUND Atrial fibrillation(AF)is the most common cardiac arrhythmia worldwide,hosting numerous serious possible complications such as stroke and heart failure.In the past two decades,managing rhythm control was mo...BACKGROUND Atrial fibrillation(AF)is the most common cardiac arrhythmia worldwide,hosting numerous serious possible complications such as stroke and heart failure.In the past two decades,managing rhythm control was more successful via pulmonary vein isolation(PVI)ablation,generally performed via transfemoral access.Patients with anatomical variations may necessitate a dose of creativity and evidence-based techniques.To our knowledge,we present the first PVI case in a patient with AF via right internal jugular(IJ)vein access using pulse field ablation.CASE SUMMARY A 76-year-old male with an extensive medical history notable for type 2 diabetes and severe peripheral vascular disease requiring vascular bypass surgery is identified to have paroxysmal AF.Given functional decline and worsening arrhythmia burden refractory to oral antiarrhythmics,an initial PVI ablation was attempted but failed as the catheter could not be advanced secondary to bilateral iliac vein occlusions.This necessitated a novel approach and a subsequent PVI ablation via the right IJ vein was successful without any complications.The success of this case highlights the feasibility of an IJ approach for PVI in patients where traditional access is not possible.This case can be used as a reference for other practitioners who may face similar challenges when attempting to perform PVI for AF or similar procedures requiring access to similar anatomical locations.CONCLUSION The success of this case highlights the feasibility of an IJ approach for PVI when traditional access is impossible.展开更多
BACKGROUND Sleep disorders are common health problems in the elderly.The effect of social isolation on sleep duration and sleep quality remains unclear in the Chinese community-dwelling elderly.AIM To explore the asso...BACKGROUND Sleep disorders are common health problems in the elderly.The effect of social isolation on sleep duration and sleep quality remains unclear in the Chinese community-dwelling elderly.AIM To explore the associations of social isolation with sleep duration and sleep quality in community-dwelling elderly people.METHODS A total of 7762 community-dwelling elderly people aged 60 years and older in Ningbo were recruited from June 2022 to August 2022.Data were collected using a questionnaire.Multivariate logistic regression was used to analyze the associations of social isolation with sleep duration and sleep quality.The KHB mediating effect model was used to test the mediating effect of depression and anxiety on these associations.RESULTS Among the participants,2656(34.2%)had abnormal sleep duration(<6 hours or>8 hours),1115(14.4%)had poor sleep quality,and 917(11.8%)had social isolation.After adjusting for confounding factors,compared with the elderly without social isolation,the odds ratios(95%CI)of abnormal sleep duration and poor sleep quality in the elderly with social isolation were 1.49(1.29-1.73)and 1.32(1.09-1.59),respectively.Depression partially mediated the associations of social isolation with sleep duration and sleep quality,accounting for 5.68%and 9.87%of the mediating effect,respectively.CONCLUSION Social isolation was found to be associated with sleep duration and sleep quality in community-dwelling elderly people.More attention should be paid to social isolation in the elderly.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
Laminated elastomeric bearings used in seismic isolation rely on the mechanical properties of their constituent elastomers to ensure effective performance.However,despite their resistance to temperature fluctuations a...Laminated elastomeric bearings used in seismic isolation rely on the mechanical properties of their constituent elastomers to ensure effective performance.However,despite their resistance to temperature fluctuations and environmental aggressors,silicone elastomers exhibit relatively low stiffness,limiting their direct applicability in seismic isolation.This study investigates the effect of fumed silica as a reinforcing filler to enhance the mechanical properties of laminated silicone elastomeric bearings.Elastomeric samples were fabricated with varying fumed silica proportions and subjected to Shore A hardness,uniaxial tensile,and lap shear tests to assess the influence of filler content.Additionally,quasi-static tests were conducted on reduced-scale bearing prototypes under combined vertical compression and cyclic horizontal shear to evaluate their seismic isolation performance.The results demonstrate that fumed silica reinforcement significantly increases stiffness,as evidenced by higher Shore A hardness values.However,a trade-off was observed in tensile properties,with reductions in tensile strength and elongation at break.Despite this,the equivalent elastic modulus did not show substantial variation up to large deformations,indicating that stiffness is preserved under most working conditions.Lap shear tests showed that fumed silica improves shear resistance,while quasi-static tests revealed inelastic behavior with small increases in equivalent shear coefficients but no substantial loss in damping ratios.These findings suggest that fumed silica reinforcement enhances silicone elastomers’stiffness and shear resistance while maintaining moderate damping properties,making it a promising approach for improving the mechanical performance of elastomeric bearings in seismic isolation applications.展开更多
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).
基金Chongqing Technological Innovation and Application Development Major Project,Grant/Award Number:CSTB2024TIAD-STX0024.
文摘Gate drivers for high-voltage silicon carbide(SiC)converters require a reliable power supply with strong isolation and compact size.However,existing gate driver power supplies(GDPS)with the transformer structure make it difficult to enhance the isolation performance while keeping the small coupling capacitance and volume.This paper firstly presents a novel wireless GDPS with an improved Class-E inverter for high-voltage energy harvesting applications.The proposed design requires only one switch and reduces the input inductor significantly.Meanwhile,it solves the issue of harmful surge currents and maintains a zero-voltage-switching state when the load changes.Finally,a compact wireless GDPS prototype is developed and the insulation characteristics are studied.Results demonstrate that the proposed design achieves isolation voltage up to 17.7 kV with the smallest size volume and extra-low coupling capacitance of 1.83 pF.
文摘Mesenchymal stem cells are highly regarded for their potential in tissue repair and regenerative medicine due to their multipotency and self-renewal abilities.Recently,mesenchymal stem cells have been redefined as“medical signaling cells,”with their primary biological effects mediated through exosome secretion.These exosomes,which contain lipids,proteins,RNA,and metabolites,are crucial in regulating various biological processes and enhancing regenerative therapies.Exosomes replicate the effects of their parent cells while offering benefits such as reduced side effects,low immunogenicity,excellent biocompatibility,and high drug-loading capacity.Dental stem cells,including those from apical papilla,gingiva,dental pulp,and other sources,are key contributors to exosome-mediated regenerative effects,such as tumor cell apoptosis,neuroprotection,angiogenesis,osteogenesis,and immune modulation.Despite their promise,clinical application of exosomes is limited by challenges in isolation techniques.Current methods face issues of complexity,inefficiency,and insufficient purity,hindering detailed analysis.Recent advancements,such as micro-electromechanical systems,alternating current electroosmosis,and serum-free three-dimensional cell cultures,have improved exosome isolation efficacy.This review synthesizes nearly 200 studies on dental stem cell-derived exosomes,highlighting their potential in treating a wide range of conditions,including periodontal diseases,cancer,neurodegenerative disorders,diabetes,and more.Optimized isolation methods offer a path forward for overcoming current limitations and advancing the clinical use of exosome-based therapies.
文摘As industrialization and informatization in China deeply integrate and the Internet of Things rapidly develops,industrial control systems are facing increasingly severe information security challenges.The industrial control system of the gas extraction plant is characterized by numerous points and centralized operations,with a strong reliance on the system and stringent real-time requirements.
基金Supported by National Key Basic Research Program of China(973 Program)(2017YFD0500605)
文摘[Objectives]This study aimed to investigate the pathogenicity,growth characteristics and drug resistance of Streptococcus suis type 2.[Methods]Bacterial isolation and identification,biochemical experiments,determination of growth curve and correlation curve between OD 600 values and viable counts,drug susceptibility tests,pathogenicity analysis,and histopathological observations were carried out.[Results]The Streptococcus strain isolated from infected pigs was identified as Streptococcus suis type 2,which was named TA01 strain.TA01 strain reached the growth peak at 6-8 h post-incubation,and viable counts gradually declined after 8 h of incubation.The correlation equation between OD 600 values and viable counts is y=24.659 x-1.076 1,R^2=0.996 7.TA01 strain was sensitive to penicillin,erythromycin,florfenicol and oxacillin,and resistant to ciprofloxacin,polymyxin B and clindamycin.According to the results of pathogenicity analysis,all the mice in 3.6×10^9 cfu/mouse group died within 48,and these dead mice exhibited acute pyaemia septica.Based on the Reed-Muench formula,it was calculated that LD 50 of TA01 strain was 1.137×10^8 cfu/mouse.Pathological examination showed obvious blue-stained bacteria clusters,accompanied by neutrophil infiltration.[Conclusions]TA01 strain was a virulent strain of Streptococcus suis type 2.Compared with Streptococcus strains which were isolated and reported in China,TA01 strain exhibited strong virulence and rapid proliferation.
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.
文摘This research aims to address the challenges of fault detection and isolation(FDI)in digital grids,focusing on improving the reliability and stability of power systems.Traditional fault detection techniques,such as rule-based fuzzy systems and conventional FDI methods,often struggle with the dynamic nature of modern grids,resulting in delays and inaccuracies in fault classification.To overcome these limitations,this study introduces a Hybrid NeuroFuzzy Fault Detection Model that combines the adaptive learning capabilities of neural networks with the reasoning strength of fuzzy logic.The model’s performance was evaluated through extensive simulations on the IEEE 33-bus test system,considering various fault scenarios,including line-to-ground faults(LGF),three-phase short circuits(3PSC),and harmonic distortions(HD).The quantitative results show that the model achieves 97.2%accuracy,a false negative rate(FNR)of 1.9%,and a false positive rate(FPR)of 2.3%,demonstrating its high precision in fault diagnosis.The qualitative analysis further highlights the model’s adaptability and its potential for seamless integration into smart grids,micro grids,and renewable energy systems.By dynamically refining fuzzy inference rules,the model enhances fault detection efficiency without compromising computational feasibility.These findings contribute to the development of more resilient and adaptive fault management systems,paving the way for advanced smart grid technologies.
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 projects of the National Natural Science Foundation of China(Nos.41272360,41472299,41672322)
文摘Constructing a statistical model that best fits the background is a key step in geochemical anomaly identification. But the model is hard to be constructed in situations where the sample population has unknown and/or complex distribution. Isolation forest is an outlier detection approach that explicitly isolates anomaly samples rather than models the population distribution. It can extract multivariate anomalies from huge-sized high-dimensional data with unknown population distribution. For this reason,we tentatively applied the method to identify multivariate anomalies from the stream sediment survey data of the Lalingzaohuo district,an area with a complex geological setting,in Qinghai Province in China. The performance of the isolation forest algorithm in anomaly identification was compared with that of a continuous restricted Boltzmann machine. The results show that the isolation forest model performs superiorly to the continuous restricted Boltzmann machine in multivariate anomaly identification in terms of receiver operating characteristic curve,area under the curve,and data-processing efficiency. The anomalies identified by the isolation forest model occupy 19% of the study area and contain 82% of the known mineral deposits,whereas the anomalies identified by the continuous restricted Boltzmann machine occupy 35% of the study area and contain 88% of the known mineral deposits. It takes 4. 07 and 279. 36 seconds respectively handling the dataset using the two models. Therefore,isolation forest is a useful anomaly detection method that can quickly extract multivariate anomalies from geochemical exploration data.
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.
文摘The present research work was carried out to isolate and identify Newcastle disease virus (NDV) by using haemagglutination inhibition (HI) test and HA-HI virus isolation, embryonated eggs (EE) and chicken embryo fibroblasts (CEF). A total of 95 clinical (blood, tracheal and cloacal swabs) and post-mortem (brain, lung, colon and spleen) samples were collected from chickens of field outbreaks of suspected Newcastle disease virus (NDV). The HI and HA-HI were employed to detect NDV in tissue homogenates of all the clinical and post-mortem samples as well as laboratory samples (AF and ICF). Among the four different types of post-mortem samples, virus isolation rate was found to be low in body organs. In CEF cell culture system, the rate of virus isolation from all the aforesaid samples was found to be at 100% with the exception of serum samples;while in tracheal and cloacal swabs, it was at 90%;while in serum, it was at 10%, in all clinical cases. The isolation rate of NDV was higher in CEF culture system (66.7%) compared to that of avian embryos (33.3%). Samples were inoculated and the allantoic fluid (AF) of the dead embryos and the infected culture fluid (ICF) of the CEF were harvested at 24 to 96 hours of the post-infection, respectively, which revealed that the virulent strain of NDV is highly prevalent in the region. The prevalence of NDV was established at 1.1%, 2.1% and 4.2% using HA-HI, EE, and CEF methods. Rapid detection and identification of the virus are crucial for the effective control of the disease as conventional diagnostic methods such as virus isolation on embryonated eggs followed by serological identification in haemagglutination-inhibition test are laborious and time-consuming. The speed of the diagnosis can be considerably increased by using methods based on molecular biology, e.g. reverse transcription—polymerase chain reaction. However, the genetic variability of APMV-1 isolates should be considered carefully as the potential cause for false negative results of genetic-based laboratory tests.
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.
基金supported in part by National Key R&D Program of China under Grant 2024YFB4708600National Natural Science Foundation of China under Grant 52305304+3 种基金Jilin Youth Growth Technology Project under Grant 20230508147RCthe Science and Technology Research Project of Jilin Provincial Education Department(No.JJKH20231193KJ)supported in part by the National Natural Science Foundation of China under Grant 52021003 and Grant 52205565in part by the Natural Science Foundation of Jilin Province under Grant 20210101053JC.
文摘Traditional linear vibration isolators struggle to combine high load-bearing capacity with low-frequency vibration isolation, whereas nonlinear metastructure isolators can effectively fulfill both functions. This paper draws inspiration from the Quasi-Zero Stiffness (QZS) characteristics resulting from the buckling deformation of beams, and proposes a gear-based QZS structure by arranging beams in a circular array. We investigated the static mechanical behavior under different structural parameters, loading angles, and gear combinations through experiments and simulations, and demonstrated the mechanical performances could be effectively programmed. Subsequent vibration isolation tests on the double gears prove superior vibration isolation performance at low frequency while maintaining high load-bearing capacities. Additionally, a key contribution of our work is the development of a mathematical model to characterize the buckling behavior of the unit beam within the gear structure, with its accuracy validated through finite element analysis and experimental results. The gear’s modulus, number of teeth, and pressure angle are selected according to standard series, allowing the gear can be seamlessly integrated into existing mechanical systems in critical fields such as aerospace, military, and etc.
文摘Traffic-induced ground vibrations cause significant problems for residents and nearby structures.Reducing the effect of these vibrations on the neighboring environment is a key challenge,particularly in urban areas.This study presents both numerical and experimental investigations of the performance of mass scatters for screening ground vibrations.A three-dimensional numerical model is validated and extended to conduct a comparative study on the efficiency of three geotechnical methods of isolation.These methods include trench barriers,waveimpeding blocks(WIBs),and mass scatters.The results showed that mass scatters represent an efficient way of scattering ground vibrations,and their efficiency is mainly related to the weights of mass scatters and their natural frequency,which control the dynamic soil response in the frequency domain.Rigid trench barriers are less effective than soft ones,and their efficiency is more pronounced regarding the WIB.Soft barriers with a depth of an order of half of the wavelength can decrease the vibration levels by up to 50%,which is comparable to the performance of enormous mass scatters.The dimensions of WIBs must be chosen according to the wavelength of incident waves and the cutoff frequency of the topsoil layer.Considering the significant wavelength of traffic-induced vibration,the use of trench barriers or WIBs becomes impractical and expensive;therefore,mass scatters appear to be an efficient and practical solution.
基金supported by the National Key R&D Program of China(2022YFC3501805)the Science and Technology Program of Tianjin in China(23ZYJDSS00030)+2 种基金the National Natural Science Foundation of China(82374030)the Science&Technology Development Fund of Tianjin Education Commission for Higher Education(2021KJ127)Tianjin Outstanding Youth Fund(23JCJQJC00030).
文摘Panax notoginseng is a traditional Chinese medicine containing various constituents,including the saponins,polysaccharides,polyacetylenes,amino acids,etc.It has beneficial functions,such as the anti-inflammatory,antitumor,hepatoprotective,and anti-aging effects.Among these,P.notoginseng polysaccharides(PNPs)have been exploited because of their extensive pharmacological effects,being ranked as one of the current research hotspots,especially for the functional foods and medical practice.In this review,the literature related to PNPs in the past 20 years was surveyed and analyzed using both the China National Knowledge Infrastructure(CNKI)and Web of Science(WOS)databases.The visualization diagram shows that current studies on PNPs mainly focus on the antioxidant and immunomodulatory activities and structural characterization.In addition,the extraction,separation,purification,chemical analysis,structural characteristics,bioactivities,and applications of PNPs are outlined,in detail,aimed to provide valuable information for the further study,development,and utilization regarding PNPs.
文摘BACKGROUND Atrial fibrillation(AF)is the most common cardiac arrhythmia worldwide,hosting numerous serious possible complications such as stroke and heart failure.In the past two decades,managing rhythm control was more successful via pulmonary vein isolation(PVI)ablation,generally performed via transfemoral access.Patients with anatomical variations may necessitate a dose of creativity and evidence-based techniques.To our knowledge,we present the first PVI case in a patient with AF via right internal jugular(IJ)vein access using pulse field ablation.CASE SUMMARY A 76-year-old male with an extensive medical history notable for type 2 diabetes and severe peripheral vascular disease requiring vascular bypass surgery is identified to have paroxysmal AF.Given functional decline and worsening arrhythmia burden refractory to oral antiarrhythmics,an initial PVI ablation was attempted but failed as the catheter could not be advanced secondary to bilateral iliac vein occlusions.This necessitated a novel approach and a subsequent PVI ablation via the right IJ vein was successful without any complications.The success of this case highlights the feasibility of an IJ approach for PVI in patients where traditional access is not possible.This case can be used as a reference for other practitioners who may face similar challenges when attempting to perform PVI for AF or similar procedures requiring access to similar anatomical locations.CONCLUSION The success of this case highlights the feasibility of an IJ approach for PVI when traditional access is impossible.
基金Supported by Ningbo Medical and Health Brand Discipline,No.PPXK2024-07and Ningbo Top Medical and Health Research Program,No.2022030410.
文摘BACKGROUND Sleep disorders are common health problems in the elderly.The effect of social isolation on sleep duration and sleep quality remains unclear in the Chinese community-dwelling elderly.AIM To explore the associations of social isolation with sleep duration and sleep quality in community-dwelling elderly people.METHODS A total of 7762 community-dwelling elderly people aged 60 years and older in Ningbo were recruited from June 2022 to August 2022.Data were collected using a questionnaire.Multivariate logistic regression was used to analyze the associations of social isolation with sleep duration and sleep quality.The KHB mediating effect model was used to test the mediating effect of depression and anxiety on these associations.RESULTS Among the participants,2656(34.2%)had abnormal sleep duration(<6 hours or>8 hours),1115(14.4%)had poor sleep quality,and 917(11.8%)had social isolation.After adjusting for confounding factors,compared with the elderly without social isolation,the odds ratios(95%CI)of abnormal sleep duration and poor sleep quality in the elderly with social isolation were 1.49(1.29-1.73)and 1.32(1.09-1.59),respectively.Depression partially mediated the associations of social isolation with sleep duration and sleep quality,accounting for 5.68%and 9.87%of the mediating effect,respectively.CONCLUSION Social isolation was found to be associated with sleep duration and sleep quality in community-dwelling elderly people.More attention should be paid to social isolation in the elderly.
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.
文摘Laminated elastomeric bearings used in seismic isolation rely on the mechanical properties of their constituent elastomers to ensure effective performance.However,despite their resistance to temperature fluctuations and environmental aggressors,silicone elastomers exhibit relatively low stiffness,limiting their direct applicability in seismic isolation.This study investigates the effect of fumed silica as a reinforcing filler to enhance the mechanical properties of laminated silicone elastomeric bearings.Elastomeric samples were fabricated with varying fumed silica proportions and subjected to Shore A hardness,uniaxial tensile,and lap shear tests to assess the influence of filler content.Additionally,quasi-static tests were conducted on reduced-scale bearing prototypes under combined vertical compression and cyclic horizontal shear to evaluate their seismic isolation performance.The results demonstrate that fumed silica reinforcement significantly increases stiffness,as evidenced by higher Shore A hardness values.However,a trade-off was observed in tensile properties,with reductions in tensile strength and elongation at break.Despite this,the equivalent elastic modulus did not show substantial variation up to large deformations,indicating that stiffness is preserved under most working conditions.Lap shear tests showed that fumed silica improves shear resistance,while quasi-static tests revealed inelastic behavior with small increases in equivalent shear coefficients but no substantial loss in damping ratios.These findings suggest that fumed silica reinforcement enhances silicone elastomers’stiffness and shear resistance while maintaining moderate damping properties,making it a promising approach for improving the mechanical performance of elastomeric bearings in seismic isolation applications.
