[Objective] The research aimed to initially study degradation effect of the CODc, in sewage by two psychrotrophs. [Method] Two psychrotrophs were isolated from the activated sludge of wastewater treatment plant in Tia...[Objective] The research aimed to initially study degradation effect of the CODc, in sewage by two psychrotrophs. [Method] Two psychrotrophs were isolated from the activated sludge of wastewater treatment plant in Tianjin Konggang Economic Area. CODc, degradation ability of the screened psychrotroph was analyzed in simulated domestic wastewater at 6℃. [Result] K 36 was identified as Comamonas testosterone, and K 38 was identified as Serratia fonticola. CODcr degradation abilities of the two strains were different in test. COOcr removal rates of the K 36 and K 38 respectively reached up to 23% and 53%. The measured result of growth rate suggested that two psychrotrophs both had high activities at low temperature. [ Conclusion] K 36 and K 38 had potentials in wastewater treatment application.展开更多
This brief study explores the diverse and long-term mental impacts of the COVID-19 pandemic on societies worldwide. Based on the recent existing literature, six primary categories of mental effects are identified to v...This brief study explores the diverse and long-term mental impacts of the COVID-19 pandemic on societies worldwide. Based on the recent existing literature, six primary categories of mental effects are identified to verify how people are affected by reoccurring lockdowns and social isolations. The study urges holistic research in this field, suggesting that researchers must not neglect the diversity of mental health impacts and context-specific factors. While long-term mental and psychological impacts are mostly hidden for now, we anticipate them to fuel other health issues already experienced by the vulnerable groups, healthcare units, and those fighting the pandemic at the front line. The paper aims to highlight primary mental health impacts of the COVID-19 pandemic due to reoccurring lockdowns and social isolations. This is an opinion paper reflecting on ongoing research related to mental health issues of the ongoing pandemic, some of that could be looked at through case study research or extended research and comparative studies. This brief study suggests further case study-based analysis to evaluate the impacts of lockdowns and social isolations on societal wellbeing and mental health. Globally, the ongoing pandemic has made public health unstable and is expected to continue with its long-term consequences on societies. Research studies should help make governments and policymakers more aware of such long-term consequences to ensure they can respond more effectively to foreseeing public health issues.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 isolated fracture-vug systems controlled by small-scale strike-slip faults within ultra-deep carbonate rocks of the Tarim Basin exhibit significant exploration potential.The study employs a novel training set inco...The isolated fracture-vug systems controlled by small-scale strike-slip faults within ultra-deep carbonate rocks of the Tarim Basin exhibit significant exploration potential.The study employs a novel training set incorporating innovative fault labels to train a U-Net-structured CNN model,enabling effective identification of small-scale strike-slip faults through seismic data interpretation.Based on the CNN faults,we analyze the distribution patterns of small-scale strike-slip faults.The small-scale strike-slip faults can be categorized into NNW-trending and NE-trending groups with strike lengths ranging 200–5000 m.The development intensity of small-scale strike-slip faults in the Lower Yingshan Member notably exceeds that in the Upper Member.The Lower and Upper Yingshan members are two distinct mechanical layers with contrasting brittleness characteristics,separated by a low-brittleness layer.The superior brittleness of the Lower Yingshan Member enhances the development intensity of small-scale strike-slip faults compared to the upper member,while the low-brittleness layer exerts restrictive effects on vertical fault propagation.Fracture-vug systems formed by interactions of two or more small-scale strike-slip faults demonstrate larger sizes than those controlled by individual faults.All fracture-vug system sizes show positive correlations with the vertical extents of associated small-scale strike-slip faults,particularly intersection and approaching fracture-vug systems exhibit accelerated size increases proportional to the vertical extents.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
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
BACKGROUND Antibiotic resistance is a growing global health threat,and understanding local trends in bacterial isolates and their susceptibility patterns is crucial for effective infection control and antimicrobial st...BACKGROUND Antibiotic resistance is a growing global health threat,and understanding local trends in bacterial isolates and their susceptibility patterns is crucial for effective infection control and antimicrobial stewardship.The coronavirus disease 2019(COVID-19)pandemic has introduced additional complexities,potentially influencing these patterns.AIM To analyze trends in bacterial isolates and their antibiotic susceptibility patterns at Salmaniya Medical Complex from 2018 to 2023,with a specific focus on the impact of the COVID-19 pandemic on these trends.METHODS A retrospective analysis of microbiological data was conducted,covering the period from 2018 to 2023.The study included key bacterial pathogens such as Escherichia coli(E.coli),Klebsiella pneumoniae,Acinetobacter baumannii,Pseudomonas aeruginosa,and Staphylococcus aureus,among others.The antibiotic susceptibility profiles of these isolates were assessed using standard laboratory methods.To contextualize the findings,the findings were compared with similar studies from other regions,including China,India,Romania,Saudi Arabia,the United Arab Emirates,Malaysia,and United States.RESULTS The study revealed fluctuating trends in the prevalence of bacterial isolates,with notable changes during the COVID-19 pandemic.For example,a significant increase in the prevalence of Staphylococcus aureus was observed during the pandemic years,while the prevalence of E.coli showed a more variable pattern.Antibiotic resistance rates varied among the different pathogens,with a concerning rise in resistance to commonly used antibiotics,particularly among Klebsiella pneumoniae and E.coli.Additionally,the study identified an alarming increase in the prevalence of multidrug-resistant(MDR)strains,especially within Klebsiella pneumoniae and E.coli isolates.The impact of the COVID-19 pandemic on these trends was evident,with shifts in the frequency,resistance patterns,and the emergence of MDR bacteria among several key pathogens.CONCLUSION This study highlights the dynamic nature of bacterial isolates and their antibiotic susceptibility patterns at Salmaniya Medical Complex,particularly in the context of the COVID-19 pandemic.The findings underscore the need for continuous monitoring and effective anti-microbial stewardship programs to combat the evolving threat of antibiotic resistance.Further research and policy initiatives are required to address the identified challenges and improve patient outcomes in the face of these ongoing challenges.展开更多
Devices on aircraft are subjected to complex environmental excitations that pose risks to their operational safety.Passive vibration isolation techniques are extensively employed due to their advantage of not requirin...Devices on aircraft are subjected to complex environmental excitations that pose risks to their operational safety.Passive vibration isolation techniques are extensively employed due to their advantage of not requiring additional energy sources.This paper introduces a novel metallic vibration isolator based on zigzag structures.The proposed isolator features a compact design and can be manufactured using additive manufacturing techniques,allowing for the integration of structural and functional elements.Firstly,the vibration response of the single-degree-of-freedom(SDOF)system is analyzed.To achieve effective vibration reduction,it is crucial for the isolator's stiffness to be sufficiently low.Secondly,to obtain a structure with high compliance,the traversal algorithm and the finite element method(FEM)are applied.The results confirm that the zigzag structure is a reliable high-compliance configuration.Thirdly,the parametric geometric model of the zigzag structure is developed and its stiffness is calculated.Quasi-static compression experiments validate the accuracy of the calculations.Finally,a specific engineering example is considered,where a zigzag vibration isolator is designed and fabricated.Vibration experiments demonstrate that the zigzag isolator effectively reduces both the stiffness and the fundamental frequency of the vibration system,achieving a vibration isolation efficiency exceeding 60%.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
Isolated power converters have emerged as an active research topic in power integrated circuit(IC)design.Reflecting this growing interest,ISSCC 2025 has featured a dedicated session on"Isolated Power and Gate Dri...Isolated power converters have emerged as an active research topic in power integrated circuit(IC)design.Reflecting this growing interest,ISSCC 2025 has featured a dedicated session on"Isolated Power and Gate Drivers".These converters enable safe and reliable power delivery across voltage domains and are widely used in renewable energy,electric vehicles,and telecommunications.Galvanic isolation prevents surge currents and ground loop issues in harsh high-voltage environments.As demand grows for compact,efficient,and high–power-density solutions,fully integrated architectures featuring on-chip transformers are increasingly favored over traditional module-based designs,offering>5 kV isolation with a smaller footprint and lower system cost[1].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
Objective:This study investigated the outcomes of microsurgical subinguinal varicocelectomy(MSV)on semen and hormonal parameters in cases with isolated sperm defects(oligozoospermia,asthenozoospermia,or teratozoosperm...Objective:This study investigated the outcomes of microsurgical subinguinal varicocelectomy(MSV)on semen and hormonal parameters in cases with isolated sperm defects(oligozoospermia,asthenozoospermia,or teratozoospermia).Methods:A retrospective review of charts of patients who underwent MSV for clinically palpable varicocele between January 1,2011 and January 1,2019 at Hamad Medical Corporation was undertaken.All patients diagnosed with isolated oligozoospermia,asthenozoospermia,or teratozoospermia in the preoperative semen analysis were included.Men with multiple sperm defects,genetic abnormalities,azoospermia,history of genitourinary infection,exposure to chemotherapy or radiotherapy,or prior use of peri-operative fertility treatment were excluded.Data extracted from the electronic medical records included(collected before MSV and up to 6 months postoperatively):demographics(age),clinical data(fertility-related medical history and surgical interventions),family history(consanguinity and infertility),physical examination findings from general and local genital exam(varicocele side and grade),laboratory data such as semen analysis,sperm DNA fragmentation tests,and hormone levels(follicle-stimulating hormone,luteinizing hormone,total testosterone,estradiol,and prolactin),and imaging(scrotal color Doppler ultrasound).Results:A total of 331 patients with isolated sperm defects were included.Postoperatively,83.3%of patients showed an improvement in sperm concentration with a median increase of 7 millions/mL.Postoperatively,76.7%of isolated asthenozoospermic patients showed an improvement in total motility and 66.0%had an improvement in progressive motility with median increases of 15.0%and 7.5%,respectively.Postoperatively,70.0%of the teratozoospermic patients showed an improvement in normal sperm morphology with a median increase of 6%.No changes were observed in other semen or hormone parameters that were examined.Conclusion:MSV is a valid and effective treatment modality for patients with isolated sperm defects that significantly corrects their respective semen abnormality and improves their chances of natural conception.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
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
This study explores the nonlinear dynamics of a quasi-zero stiffness(QZS)vibration isolator coupled with a piezoelectric energy harvester connected to an RL-resonant circuit.The model of the system is formulated with ...This study explores the nonlinear dynamics of a quasi-zero stiffness(QZS)vibration isolator coupled with a piezoelectric energy harvester connected to an RL-resonant circuit.The model of the system is formulated with the Lagrangian mechanics,representing a two-degree-of-freedom nonlinear electromechanical system subject to harmonic base excitation under a 1:1 internal resonance condition.The model is normalized,and the conditions dictating monostable and bistable oscillation modes are identified.The bifurcation characteristics of the coupled system are analyzed in both oscillation modes by means of harmonic balance and continuation methods.The vibration isolation performance,with and without the coupled harvester,is evaluated in terms of displacement transmissibility to assess its dual functionalities for vibration isolation and energy harvesting.Analytical results demonstrate that integrating a piezoelectric harvester into a monostable QZS isolator under 1:1 internal resonance does not compromise its vibration isolation capability while enabling efficient energy harvesting at extremely low-frequency base excitation.Furthermore,the system's response under strong base excitation is investigated exclusively for energy harvesting in both monostable and bistable modes,leading to optimal structural parameter design.The conditions for intra-well and inter-well periodic oscillation modes,as well as chaotic responses,are analyzed analytically and validated numerically through stability charts,basins of attraction,bifurcation diagrams,time histories,and Poincarémaps.This work provides a comprehensive understanding of the oscillation dynamics of QZS isolators and offers valuable insights for optimizing their geometric parameters to function as high-performance vibration isolators and/or energy harvesters.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
Activity 1 Think about the following questions and write down your answers before reading the text.1.What are some possible ways animals can survive without access to fresh water sources?2.What other factors besides w...Activity 1 Think about the following questions and write down your answers before reading the text.1.What are some possible ways animals can survive without access to fresh water sources?2.What other factors besides water could contribute to the thriving(茁壮成长)of a herd of goats on an isolated island?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
基金Supported by Excellent Talent Support Plan Project in New Century, Ministry of Education,China(NCET-09-0586)Special Project of the Science Research in Public Welfare Industry,Ministry of Water Resources,China (201101018,201201114)Special Item of the National International Science and Technology Cooperation(S2013BGR0244)
文摘[Objective] The research aimed to initially study degradation effect of the CODc, in sewage by two psychrotrophs. [Method] Two psychrotrophs were isolated from the activated sludge of wastewater treatment plant in Tianjin Konggang Economic Area. CODc, degradation ability of the screened psychrotroph was analyzed in simulated domestic wastewater at 6℃. [Result] K 36 was identified as Comamonas testosterone, and K 38 was identified as Serratia fonticola. CODcr degradation abilities of the two strains were different in test. COOcr removal rates of the K 36 and K 38 respectively reached up to 23% and 53%. The measured result of growth rate suggested that two psychrotrophs both had high activities at low temperature. [ Conclusion] K 36 and K 38 had potentials in wastewater treatment application.
文摘This brief study explores the diverse and long-term mental impacts of the COVID-19 pandemic on societies worldwide. Based on the recent existing literature, six primary categories of mental effects are identified to verify how people are affected by reoccurring lockdowns and social isolations. The study urges holistic research in this field, suggesting that researchers must not neglect the diversity of mental health impacts and context-specific factors. While long-term mental and psychological impacts are mostly hidden for now, we anticipate them to fuel other health issues already experienced by the vulnerable groups, healthcare units, and those fighting the pandemic at the front line. The paper aims to highlight primary mental health impacts of the COVID-19 pandemic due to reoccurring lockdowns and social isolations. This is an opinion paper reflecting on ongoing research related to mental health issues of the ongoing pandemic, some of that could be looked at through case study research or extended research and comparative studies. This brief study suggests further case study-based analysis to evaluate the impacts of lockdowns and social isolations on societal wellbeing and mental health. Globally, the ongoing pandemic has made public health unstable and is expected to continue with its long-term consequences on societies. Research studies should help make governments and policymakers more aware of such long-term consequences to ensure they can respond more effectively to foreseeing public health issues.
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 by the National Natural Science Foundation of China(No.U21B2062).
文摘The isolated fracture-vug systems controlled by small-scale strike-slip faults within ultra-deep carbonate rocks of the Tarim Basin exhibit significant exploration potential.The study employs a novel training set incorporating innovative fault labels to train a U-Net-structured CNN model,enabling effective identification of small-scale strike-slip faults through seismic data interpretation.Based on the CNN faults,we analyze the distribution patterns of small-scale strike-slip faults.The small-scale strike-slip faults can be categorized into NNW-trending and NE-trending groups with strike lengths ranging 200–5000 m.The development intensity of small-scale strike-slip faults in the Lower Yingshan Member notably exceeds that in the Upper Member.The Lower and Upper Yingshan members are two distinct mechanical layers with contrasting brittleness characteristics,separated by a low-brittleness layer.The superior brittleness of the Lower Yingshan Member enhances the development intensity of small-scale strike-slip faults compared to the upper member,while the low-brittleness layer exerts restrictive effects on vertical fault propagation.Fracture-vug systems formed by interactions of two or more small-scale strike-slip faults demonstrate larger sizes than those controlled by individual faults.All fracture-vug system sizes show positive correlations with the vertical extents of associated small-scale strike-slip faults,particularly intersection and approaching fracture-vug systems exhibit accelerated size increases proportional to the vertical extents.
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.
文摘BACKGROUND Antibiotic resistance is a growing global health threat,and understanding local trends in bacterial isolates and their susceptibility patterns is crucial for effective infection control and antimicrobial stewardship.The coronavirus disease 2019(COVID-19)pandemic has introduced additional complexities,potentially influencing these patterns.AIM To analyze trends in bacterial isolates and their antibiotic susceptibility patterns at Salmaniya Medical Complex from 2018 to 2023,with a specific focus on the impact of the COVID-19 pandemic on these trends.METHODS A retrospective analysis of microbiological data was conducted,covering the period from 2018 to 2023.The study included key bacterial pathogens such as Escherichia coli(E.coli),Klebsiella pneumoniae,Acinetobacter baumannii,Pseudomonas aeruginosa,and Staphylococcus aureus,among others.The antibiotic susceptibility profiles of these isolates were assessed using standard laboratory methods.To contextualize the findings,the findings were compared with similar studies from other regions,including China,India,Romania,Saudi Arabia,the United Arab Emirates,Malaysia,and United States.RESULTS The study revealed fluctuating trends in the prevalence of bacterial isolates,with notable changes during the COVID-19 pandemic.For example,a significant increase in the prevalence of Staphylococcus aureus was observed during the pandemic years,while the prevalence of E.coli showed a more variable pattern.Antibiotic resistance rates varied among the different pathogens,with a concerning rise in resistance to commonly used antibiotics,particularly among Klebsiella pneumoniae and E.coli.Additionally,the study identified an alarming increase in the prevalence of multidrug-resistant(MDR)strains,especially within Klebsiella pneumoniae and E.coli isolates.The impact of the COVID-19 pandemic on these trends was evident,with shifts in the frequency,resistance patterns,and the emergence of MDR bacteria among several key pathogens.CONCLUSION This study highlights the dynamic nature of bacterial isolates and their antibiotic susceptibility patterns at Salmaniya Medical Complex,particularly in the context of the COVID-19 pandemic.The findings underscore the need for continuous monitoring and effective anti-microbial stewardship programs to combat the evolving threat of antibiotic resistance.Further research and policy initiatives are required to address the identified challenges and improve patient outcomes in the face of these ongoing challenges.
基金supported by the National Key Research and Development Program of China(Nos.2023YFB4603900,2023YFB4603901)the National Natural Science Foundation of China(No.52275255)。
文摘Devices on aircraft are subjected to complex environmental excitations that pose risks to their operational safety.Passive vibration isolation techniques are extensively employed due to their advantage of not requiring additional energy sources.This paper introduces a novel metallic vibration isolator based on zigzag structures.The proposed isolator features a compact design and can be manufactured using additive manufacturing techniques,allowing for the integration of structural and functional elements.Firstly,the vibration response of the single-degree-of-freedom(SDOF)system is analyzed.To achieve effective vibration reduction,it is crucial for the isolator's stiffness to be sufficiently low.Secondly,to obtain a structure with high compliance,the traversal algorithm and the finite element method(FEM)are applied.The results confirm that the zigzag structure is a reliable high-compliance configuration.Thirdly,the parametric geometric model of the zigzag structure is developed and its stiffness is calculated.Quasi-static compression experiments validate the accuracy of the calculations.Finally,a specific engineering example is considered,where a zigzag vibration isolator is designed and fabricated.Vibration experiments demonstrate that the zigzag isolator effectively reduces both the stiffness and the fundamental frequency of the vibration system,achieving a vibration isolation efficiency exceeding 60%.
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 in part by the National Natural Science Foundation of China under Grant U23A20353.
文摘Isolated power converters have emerged as an active research topic in power integrated circuit(IC)design.Reflecting this growing interest,ISSCC 2025 has featured a dedicated session on"Isolated Power and Gate Drivers".These converters enable safe and reliable power delivery across voltage domains and are widely used in renewable energy,electric vehicles,and telecommunications.Galvanic isolation prevents surge currents and ground loop issues in harsh high-voltage environments.As demand grows for compact,efficient,and high–power-density solutions,fully integrated architectures featuring on-chip transformers are increasingly favored over traditional module-based designs,offering>5 kV isolation with a smaller footprint and lower system cost[1].
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Objective:This study investigated the outcomes of microsurgical subinguinal varicocelectomy(MSV)on semen and hormonal parameters in cases with isolated sperm defects(oligozoospermia,asthenozoospermia,or teratozoospermia).Methods:A retrospective review of charts of patients who underwent MSV for clinically palpable varicocele between January 1,2011 and January 1,2019 at Hamad Medical Corporation was undertaken.All patients diagnosed with isolated oligozoospermia,asthenozoospermia,or teratozoospermia in the preoperative semen analysis were included.Men with multiple sperm defects,genetic abnormalities,azoospermia,history of genitourinary infection,exposure to chemotherapy or radiotherapy,or prior use of peri-operative fertility treatment were excluded.Data extracted from the electronic medical records included(collected before MSV and up to 6 months postoperatively):demographics(age),clinical data(fertility-related medical history and surgical interventions),family history(consanguinity and infertility),physical examination findings from general and local genital exam(varicocele side and grade),laboratory data such as semen analysis,sperm DNA fragmentation tests,and hormone levels(follicle-stimulating hormone,luteinizing hormone,total testosterone,estradiol,and prolactin),and imaging(scrotal color Doppler ultrasound).Results:A total of 331 patients with isolated sperm defects were included.Postoperatively,83.3%of patients showed an improvement in sperm concentration with a median increase of 7 millions/mL.Postoperatively,76.7%of isolated asthenozoospermic patients showed an improvement in total motility and 66.0%had an improvement in progressive motility with median increases of 15.0%and 7.5%,respectively.Postoperatively,70.0%of the teratozoospermic patients showed an improvement in normal sperm morphology with a median increase of 6%.No changes were observed in other semen or hormone parameters that were examined.Conclusion:MSV is a valid and effective treatment modality for patients with isolated sperm defects that significantly corrects their respective semen abnormality and improves their chances of natural conception.
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Project supported by the National Key R&D Program of China(No.2023YFE0125900)。
文摘This study explores the nonlinear dynamics of a quasi-zero stiffness(QZS)vibration isolator coupled with a piezoelectric energy harvester connected to an RL-resonant circuit.The model of the system is formulated with the Lagrangian mechanics,representing a two-degree-of-freedom nonlinear electromechanical system subject to harmonic base excitation under a 1:1 internal resonance condition.The model is normalized,and the conditions dictating monostable and bistable oscillation modes are identified.The bifurcation characteristics of the coupled system are analyzed in both oscillation modes by means of harmonic balance and continuation methods.The vibration isolation performance,with and without the coupled harvester,is evaluated in terms of displacement transmissibility to assess its dual functionalities for vibration isolation and energy harvesting.Analytical results demonstrate that integrating a piezoelectric harvester into a monostable QZS isolator under 1:1 internal resonance does not compromise its vibration isolation capability while enabling efficient energy harvesting at extremely low-frequency base excitation.Furthermore,the system's response under strong base excitation is investigated exclusively for energy harvesting in both monostable and bistable modes,leading to optimal structural parameter design.The conditions for intra-well and inter-well periodic oscillation modes,as well as chaotic responses,are analyzed analytically and validated numerically through stability charts,basins of attraction,bifurcation diagrams,time histories,and Poincarémaps.This work provides a comprehensive understanding of the oscillation dynamics of QZS isolators and offers valuable insights for optimizing their geometric parameters to function as high-performance vibration isolators and/or energy harvesters.
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Activity 1 Think about the following questions and write down your answers before reading the text.1.What are some possible ways animals can survive without access to fresh water sources?2.What other factors besides water could contribute to the thriving(茁壮成长)of a herd of goats on an isolated island?
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.
