Climate change has well-documented psychological consequences for society.However,the emotional experiences of frontline conservation professionals remain underexplored.As key knowledge producers and participants in d...Climate change has well-documented psychological consequences for society.However,the emotional experiences of frontline conservation professionals remain underexplored.As key knowledge producers and participants in decision-making processes,conservation researchers play a crucial role in shaping and implementing adaptation and mitigation efforts,which are pivotal for effective climate planning.Understanding their emotional responses is essential for enhancing the success of these strategies and supporting climate action.This study aims to identify the most prevalent emotions experienced by conservation researchers regarding climate change across various countries and to examine the qualitative and quantitative factors shaping these emotions.An online survey was conducted with 362 participants from 98 academic and research institutions,utilising both closed and open-ended questions to capture demographic data,climate knowledge,stances on mitigation and adaptation,and emotional responses.Data analysis revealed that feelings of powerlessness,guilt,and concern were most frequently reported,driven by a profound sense of inability to halt climate change,frustration with perceived inaction by governments and industries,and self-assessed personal shortcomings.Age and stances on climate adaptation were identified as primary factors influencing emotional responses,particularly among individuals aged 20–50 and 61–70,with opposition to adaptation correlating with stronger emotional reactions.Demographic factors such as region,place of residence,and mitigation stances played a minor role.These findings provide valuable insights into the psychological well-being of conservation researchers related to climate change.展开更多
Purpose:Diaspora researchers work in one country but have ancestral origins in another,either through moves during a research career(mobile diaspora researchers)or by starting research in the target country(embedded d...Purpose:Diaspora researchers work in one country but have ancestral origins in another,either through moves during a research career(mobile diaspora researchers)or by starting research in the target country(embedded diaspora researchers).Whilst mobile researchers might be tracked through affiliation changes in bibliometric databases,embedded researchers cannot.This article reports an evidence-based discussion of which countries’diaspora researchers can be partially tracked using first or last names,addressing this limitation.Design/methodology/approach:A frequency analysis of first and last names of authors of all Scopus journal articles 2001-2021 for 200 countries or regions.Findings:There are great variations in the extent to which first or last names are uniquely national,from Monserrat(no unique first names)to Thailand(81%unique last names).Nevertheless,most countries have a subset of first or last names that are relatively unique.For the 50 countries with the most researchers,authors with relatively national names are always more likely to research their name-associated country,suggesting a continued national association.Lists of researchers’first and last name frequencies and proportions are provided for 200 countries/regions.Research limitations:Only one period is tracked(2001-2021)and no attempt was made to validate the ancestral origins of any researcher.Practical implications:Simple name heuristics can be used to identify the international spread of a sample of most countries’diaspora researchers,but some manual checks of individual names are needed to weed out false matches.This can supplement mobile researcher data from bibliometric databases.Originality/value:This is the first attempt to list name associations for the authors of all countries and large regions,and to identify the countries for which diaspora researchers could be tracked by name.展开更多
Purpose:The ranking lists of highly cited researchers receive much public attention.In common interpretations,highly cited researchers are perceived to have made extraordinary contributions to science.Thus,the metrics...Purpose:The ranking lists of highly cited researchers receive much public attention.In common interpretations,highly cited researchers are perceived to have made extraordinary contributions to science.Thus,the metrics of highly cited researchers are often linked to notions of breakthroughs,scientific excellence,and lone geniuses.Design/methodology/approach:In this study,we analyze a sample of individuals who appear on Clarivate Analytics’Highly Cited Researchers list.The main purpose is to juxtapose the characteristics of their research performance against the claim that the list captures a small fraction of the researcher population that contributes disproportionately to extending the frontier and gaining—on behalf of society—knowledge and innovations that make the world healthier,richer,sustainable,and more secure.Findings:The study reveals that the highly cited articles of the selected individuals generally have a very large number of authors.Thus,these papers seldom represent individual contributions but rather are the result of large collective research efforts conducted in research consortia.This challenges the common perception of highly cited researchers as individual geniuses who can be singled out for their extraordinary contributions.Moreover,the study indicates that a few of the individuals have not even contributed to highly cited original research but rather to reviews or clinical guidelines.Finally,the large number of authors of the papers implies that the ranking list is very sensitive to the specific method used for allocating papers and citations to individuals.In the"whole count"methodology applied by Clarivate Analytics,each author gets full credit of the papers regardless of the number of additional co-authors.The study shows that the ranking list would look very different using an alternative fractionalised methodology.Research limitations:The study is based on a limited part of the total population of highly cited researchers.Practical implications:It is concluded that"excellence"understood as highly cited encompasses very different types of research and researchers of which many do not fit with dominant preconceptions.Originality/value:The study develops further knowledge on highly cited researchers,addressing questions such as who becomes highly cited and the type of research that benefits by defining excellence in terms of citation scores and specific counting methods.展开更多
Opening a new scientific frontier lying under the Antarctic ice, Russian researchers have drilled down and finally reached the surface of the gigantic freshwater lake, Lake Vostok. The mission chief likened the achiev...Opening a new scientific frontier lying under the Antarctic ice, Russian researchers have drilled down and finally reached the surface of the gigantic freshwater lake, Lake Vostok. The mission chief likened the achievement to placing a man on the moon. Drilling in the area of the lake began 22 years ago in 1990, but progressed slowly as a result of funding shortages, equipment breakdowns, difficulties of drilling in the ＂warm＂ ice, and environmental concerns. In 1996, six years after drilling was started, a group of Russian and British scientists discovered the lake believed to be one of the largest fresh water reservoirs on the planet. This lake is among the last unexplored places on Earth. Sealed from the Earth＇s atmosphere for millions of years, it may provide vital information about microbial evolution, the past climate of the Earth, and the formation of the Antarctic ice sheet. Russian experts waited several years for international approval of their drilling technology before proceeding. As anticipated, lake water under pressure rushed up the borehole, pushing the drilling fluid up and away, then froze, forming a protective plug that prevented contamination of the lake. In December of the next Antarctic season, 2012--2013, researchers plan to re-drill the frozen sample of subglacial water for analysis.展开更多
Gene deletion has been a valuable tool for unraveling the mysteries of molecular biology.Early approaches included gene trapping and gene targetting to disrupt or delete a gene randomly or at a specific location,respe...Gene deletion has been a valuable tool for unraveling the mysteries of molecular biology.Early approaches included gene trapping and gene targetting to disrupt or delete a gene randomly or at a specific location,respectively.Using these technologies in mouse embryos led to the generation of mouse knocko ut models and many scientific discoveries.The efficacy and specificity of these approaches have significantly increased with the advent of new technology such as cluste red regula rly inters paced short palindromic repeats for targetted gene deletion.However,several limitations including unwanted off-target gene deletion have hindered their widespread use in the field.Crerecombinase technology has provided additional capacity for cell-specific gene deletion.In this review,we provide a summary of currently available literature on the application of this system for targetted deletion of neuronal genes.This article has been constructed to provide some background info rmation for the new trainees on the mechanism and to provide necessary information for the design,and application of the Cre-recombinase system thro ugh reviewing the most f requent promoters that are currently available for genetic manipulation of neuro ns.We additionally will provide a summary of the latest technological developments that can be used for targeting neurons.This may also serve as a general guide for the selection of appropriate models for biomedical research.展开更多
Lanthanide(Ln^(3+))-doped photon avalanche(PA)upconversion nanoparticles(UCNPs)have great prospects in many frontier applications,such as super-resolution bioimaging,miniaturized lasers,single-molecule tracking,and qu...Lanthanide(Ln^(3+))-doped photon avalanche(PA)upconversion nanoparticles(UCNPs)have great prospects in many frontier applications,such as super-resolution bioimaging,miniaturized lasers,single-molecule tracking,and quantum optics.However,it remains challenging to realize PA in colloidal Ln^(3+)-doped UCNPs at room temperature(RT),due to the deleterious quenching effect associated with the surface and lattice OH^(-)defects.展开更多
This paper focuses on the remarkable contributions and achievements of Dr.Azar Andami(1926–1984),a renowned physician and specialist at the Pasteur Institute of Iran.Dr.Andami conducted extensive research on infectio...This paper focuses on the remarkable contributions and achievements of Dr.Azar Andami(1926–1984),a renowned physician and specialist at the Pasteur Institute of Iran.Dr.Andami conducted extensive research on infectious diseases,particularly cholera,utilizing her knowledge in medicine,bacteriology,and laboratory sciences.She played a crucial role in the mass production of the cholera vaccine at the Pasteur Institute of Iran and in controlling the spread of communicable diseases both locally and globally.This paper aims to highlight her remarkable works and accomplishments.展开更多
Purpose:This study was carried out to uncover the characteristics of information seeking behavior of researchers as faculty/student team members.Design/methodology/approach:An inventory encompassing 6 dimensions of in...Purpose:This study was carried out to uncover the characteristics of information seeking behavior of researchers as faculty/student team members.Design/methodology/approach:An inventory encompassing 6 dimensions of information seeking behavior was developed:Information awareness,information acquisition,information evaluation,information organization and management,information utilization and information ethics.Data was collected on 306 respondents from 52 faculty/student teams in Central South University in China and analyzed using SPSS 18.0 software.Findings:Significant differences were found among researchers with different genders in information awareness and in different academic disciplines in information acquisition and information utilization.The survey shows the characteristics of information seeking behavior of different gender groups and different teams:1) male participants got higher scores in all of the 6 dimensions of information seeking behavior;2) small teams performed best,followed by middle-sized teams and large teams;3) faculty/doctoral student teams possessed better information seeking skills than faculty/master’s student teams or faculty/doctoral and master’s student teams:4) medical teams achieved the highest level in all of the 6 dimensions of information seeking behavior,whereas natural science teams the lowest level.Medical and engineering teams were rated higher than other teams in information acquisition and information utilization.Research limitations:The small population size and doctoral students accounting for only a small portion of the respondents in the sample limit the generalization of our findings.Practical implications:The findings of this study have some implications for research and practice,especially for educational institutions,library science and information literacy training.Originality/value:This paper is the first to describe and analyze the characteristics of information seeking behavior of researchers as faculty/student team members.展开更多
为探究节水灌溉以及品种类型对再生稻产量和稻米品质的影响,2023年在湖北蕲春和浠水开展大田试验。以3个节水抗旱稻品种(旱优8200、旱优116和旱优73)和3个优质稻品种(箴两优郢香丝苗、荃优粤农丝苗和荃优607)为供试材料,以湖北省再生稻...为探究节水灌溉以及品种类型对再生稻产量和稻米品质的影响,2023年在湖北蕲春和浠水开展大田试验。以3个节水抗旱稻品种(旱优8200、旱优116和旱优73)和3个优质稻品种(箴两优郢香丝苗、荃优粤农丝苗和荃优607)为供试材料,以湖北省再生稻大面积种植的普通水稻品种(两优6326)为对照,设置常规灌溉和节水灌溉2种水分管理方式,分析再生稻模式下不同品种产量和稻米品质对水分管理的响应差异。结果表明,相较于常规灌溉,节水灌溉处理使头季和再生季灌水量分别平均减少76%和85%,但产量和稻米的加工、外观和蒸煮食味品质在水分处理间无显著差异,且这一结果在不同试验地点间保持一致。这表明,与常规灌溉相比,节水抗旱稻和优质稻品种在节水灌溉条件下均能保持较为稳定的头季和再生季产量和稻米品质。优质稻头季和再生季产量分别为8.54 t hm^(-2)和5.88 t hm^(-2),相较于普通水稻产量差异不显著;但头季和再生季整精米率分别显著提高13.5个百分点和20.6个百分点,垩白粒率和垩白度分别显著降低22.6个百分点和6.4个百分点、10.8个百分点和1.8个百分点。节水抗旱稻在头季的产量以及稻米加工、外观和蒸煮食味品质方面与普通水稻无显著差异,但在再生季,产量显著下降17%,整精米率显著提高17.0个百分点,垩白粒率和垩白度分别降低5.5个百分点和1.0个百分点。在同一品种类型中,再生稻产量和稻米品质存在显著的品种间差异。相关性分析表明,再生季稻米的加工、外观和蒸煮食味品质指标均与头季相应指标呈正相关。因此,在降水条件较好的地区,结合优良水稻品种,实施“以雨养为主、关键生育期适时灌溉”的节水灌溉策略,可有效降低水分消耗、提升水分利用效率,同时实现再生稻的高产与优质目标。展开更多
Traumatic brain injury can be categorized into primary and secondary injuries.Secondary injuries are the main cause of disability following traumatic brain injury,which involves a complex multicellular cascade.Microgl...Traumatic brain injury can be categorized into primary and secondary injuries.Secondary injuries are the main cause of disability following traumatic brain injury,which involves a complex multicellular cascade.Microglia play an important role in secondary injury and can be activated in response to traumatic brain injury.In this article,we review the origin and classification of microglia as well as the dynamic changes of microglia in traumatic brain injury.We also clarify the microglial polarization pathways and the therapeutic drugs targeting activated microglia.We found that regulating the signaling pathways involved in pro-inflammatory and anti-inflammatory microglia,such as the Toll-like receptor 4/nuclear factor-kappa B,mitogen-activated protein kinase,Janus kinase/signal transducer and activator of transcription,phosphoinositide 3-kinase/protein kinase B,Notch,and high mobility group box 1 pathways,can alleviate the inflammatory response triggered by microglia in traumatic brain injury,thereby exerting neuroprotective effects.We also reviewed the strategies developed on the basis of these pathways,such as drug and cell replacement therapies.Drugs that modulate inflammatory factors,such as rosuvastatin,have been shown to promote the polarization of antiinflammatory microglia and reduce the inflammatory response caused by traumatic brain injury.Mesenchymal stem cells possess anti-inflammatory properties,and clinical studies have confirmed their significant efficacy and safety in patients with traumatic brain injury.Additionally,advancements in mesenchymal stem cell-delivery methods—such as combinations of novel biomaterials,genetic engineering,and mesenchymal stem cell exosome therapy—have greatly enhanced the efficiency and therapeutic effects of mesenchymal stem cells in animal models.However,numerous challenges in the application of drug and mesenchymal stem cell treatment strategies remain to be addressed.In the future,new technologies,such as single-cell RNA sequencing and transcriptome analysis,can facilitate further experimental studies.Moreover,research involving non-human primates can help translate these treatment strategies to clinical practice.展开更多
Short-chain fatty acids,metabolites produced by the fermentation of dietary fiber by gut microbiota,have garnered significant attention due to their correlation with neurodegenerative diseases,particularly Parkinson’...Short-chain fatty acids,metabolites produced by the fermentation of dietary fiber by gut microbiota,have garnered significant attention due to their correlation with neurodegenerative diseases,particularly Parkinson’s disease.In this review,we summarize the changes in short-chain fatty acid levels and the abundance of short-chain fatty acid-producing bacteria in various samples from patients with Parkinson’s disease,highlighting the critical role of gut homeostasis imbalance in the pathogenesis and progression of the disease.Focusing on the nervous system,we discuss the molecular mechanisms by which short-chain fatty acids influence the homeostasis of both the enteric nervous system and the central nervous system.We identify key processes,including the activation of G protein-coupled receptors and the inhibition of histone deacetylases by short-chain fatty acids.Importantly,structural or functional disruptions in the enteric nervous system mediated by these fatty acids may lead to abnormalα-synuclein expression and gastrointestinal dysmotility,which could serve as an initiating event in Parkinson’s disease.Furthermore,we propose that short-chain fatty acids help establish communication between the enteric nervous system and the central nervous system via the vagal nerve,immune circulation,and endocrine signaling.This communication may shed light on their potential role in the transmission ofα-synuclein from the gut to the brain.Finally,we elucidate novel treatment strategies for Parkinson’s disease that target short-chain fatty acids and examine the challenges associated with translating short-chain fatty acid-based therapies into clinical practice.In conclusion,this review emphasizes the pivotal role of short-chain fatty acids in regulating gut-brain axis integrity and their significance in the pathogenesis of Parkinson’s disease from the perspective of the nervous system.Moreover,it highlights the potential value of short-chain fatty acids in early intervention for Parkinson’s disease.Future research into the molecular mechanisms of short-chain fatty acids and their synergistic interactions with other gut metabolites is likely to advance the clinical translation of innovative short-chain fatty acid-based therapies for Parkinson’s disease.展开更多
Global brain ischemia and neurological deficit are consequences of cardiac arrest that lead to high mortality.Despite advancements in resuscitation science,our limited understanding of the cellular and molecular mecha...Global brain ischemia and neurological deficit are consequences of cardiac arrest that lead to high mortality.Despite advancements in resuscitation science,our limited understanding of the cellular and molecular mechanisms underlying post-cardiac arrest brain injury have hindered the development of effective neuroprotective strategies.Previous studies primarily focused on neuronal death,potentially overlooking the contributions of non-neuronal cells and intercellular communication to the pathophysiology of cardiac arrest-induced brain injury.To address these gaps,we hypothesized that single-cell transcriptomic analysis could uncover previously unidentified cellular subpopulations,altered cell communication networks,and novel molecular mechanisms involved in post-cardiac arrest brain injury.In this study,we performed a single-cell transcriptomic analysis of the hippocampus from pigs with ventricular fibrillation-induced cardiac arrest at 6 and 24 hours following the return of spontaneous circulation,and from sham control pigs.Sequencing results revealed changes in the proportions of different cell types,suggesting post-arrest disruption in the blood-brain barrier and infiltration of neutrophils.These results were validated through western blotting,quantitative reverse transcription-polymerase chain reaction,and immunofluorescence staining.We also identified and validated a unique subcluster of activated microglia with high expression of S100A8,which increased over time following cardiac arrest.This subcluster simultaneously exhibited significant M1/M2 polarization and expressed key functional genes related to chemokines and interleukins.Additionally,we revealed the post-cardiac arrest dysfunction of oligodendrocytes and the differentiation of oligodendrocyte precursor cells into oligodendrocytes.Cell communication analysis identified enhanced post-cardiac arrest communication between neutrophils and microglia that was mediated by neutrophil-derived resistin,driving pro-inflammatory microglial polarization.Our findings provide a comprehensive single-cell map of the post-cardiac arrest hippocampus,offering potential novel targets for neuroprotection and repair following cardiac arrest.展开更多
A recently published study(Xin et al.,Prog Biochem Biophys,2026,53(2):431-441.DOI:10.3724/j.pibb.2025.0508)addresses the therapeutic challenges of pancreatic ductal adenocarcinoma(PDAC)by innovatively developing an or...A recently published study(Xin et al.,Prog Biochem Biophys,2026,53(2):431-441.DOI:10.3724/j.pibb.2025.0508)addresses the therapeutic challenges of pancreatic ductal adenocarcinoma(PDAC)by innovatively developing an orally administered nanogene delivery system.Designed to achieve in situ,efficient delivery of chimeric antigen receptor(CAR)genes to tumor sites,this approach offers a novel strategy for CAR-macrophage(CAR-M)based immunotherapy.Its key highlights are as follows.展开更多
Noncohesive particle clusters are identified and tracked in turbulent flows to determine the breakdown and time evolution of cluster statistics and their implications for interscale mass transfer,which has connections...Noncohesive particle clusters are identified and tracked in turbulent flows to determine the breakdown and time evolution of cluster statistics and their implications for interscale mass transfer,which has connections to the classical turbulent energy cascade and its mass cascade counterpart running in parallel.In particular,the formation and dynamics of sediment and larvae clusters are of interest to coral larvae settlement in coastal regions and particularly the resilience of green-gray coastal protection solutions.Analogous cluster behavior is relevant to cloud microphysics and precipitation initiation,radiation transport and light transmission through colloids and suspensions,heat and mass transfer in particle-laden flows,and viral and pollutant transmission.Following a comparison between various clustering techniques,we adopt a density-based cluster identification algorithm based on its simplicity and efficiency,where particles are clustered based on the number of neighboring particles in their individual spheres of influence.We establish parallels with lattice-based percolation theory,as evident in the power-law scaling of the cluster size distribution near the percolation threshold.The degree of discontinuity of the phase transition associated with this percolation threshold is observed to broaden with larger Stokes numbers and thereby large-scale clustering.The sensitivity of our findings to the employed clustering algorithm is discussed.A novel cluster tracking algorithm is deployed to determine the interscale transfer rate along the particle-number phase-space dimension via accounting of cluster breakup and merger events,extending previous work on the bubble breakup cascade beneath surface breaking waves.Our findings shed light on the interaction between particle clusters and their carrier turbulent flows,with an eye toward transport models incorporating cluster characteristics and dynamics.展开更多
39 soil samples surrounding a lead-zinc mining area in Guangxi were collected,and the contents of Pb,Hg,Cd,Cr,As,Cu,Zn,and Ni were determined to investigate the pollution characteristics and sources of heavy metals.Ar...39 soil samples surrounding a lead-zinc mining area in Guangxi were collected,and the contents of Pb,Hg,Cd,Cr,As,Cu,Zn,and Ni were determined to investigate the pollution characteristics and sources of heavy metals.ArcGIS inverse distance weight difference method was used to analyze the characteristics of pollution distribution,and single-factor pollution index,Nemerow comprehensive pollution index,ground accumulation index,and potential ecological risk index were selected to evaluate the characteristics of heavy metal pollution.Based on correlation analysis,the absolute principal component-multiple linear regression(APCS-MLR)and positive definite matrix factorization(PMF)models were used to analyze the sources of soil heavy metals.The results showed that the average concentrations of all eight heavy metals exceeded both national and Guangxi soil background values.Hg,Cd,and Zn exhibited high variation(greater than 0.5),indicating significant external disturbances,and their spatial distribution was closely related to mining activity locations.The single-factor pollution index evaluation indicated varying degrees of pollution risk for Cd,Zn,and As,with Cd and Zn being the most severe pollutants,as 69.23%and 30.77%of the samples fell into the moderate pollution or higher category.The geoaccumulation index analysis ranked the mean pollution levels of the eight elements as follows:Zn>Cd>Ni>Pb>Cu>Cr>Hg>As,with Cd and Zn showing the most severe contamination,and 51.28%of the samples exhibiting moderate or higher pollution levels.The Nemerow comprehensive pollution index evaluation showed that 74.35%of soil samples were classified as moderate to heavy pollution.The potential ecological risk index assessment indicated significant ecological risks posed by Cd and Zn,with 82.05%and 5.12%of the samples classified as causing strong to extreme ecological risks,respectively.The source apportionment analysis revealed minor differences between the two models.The APCS-MLR model identified three pollution sources and their contribution rates:anthropogenic mining sources(31.13%),parent material sources(40.38%),and unidentified sources(28.49%).The PMF model identified three pollution sources with contribution rates of anthropogenic mining sources(26.10%),parent material sources(46.96%),and a combined traffic and agricultural source(26.61%).Pb,Hg,Cd,and Zn mainly originated from mining activities;Cr,As,and Ni were primarily derived from the parent material,while Cu was predominantly attributed to traffic and agricultural sources.These findings provide a scientific basis for the prevention and control of heavy metal pollution in mining areas.展开更多
Dual-layer thermal barrier coatings(TBCs)with ultrahigh temperature resistance were prepared on the surface of molybdenum-rhenium alloy hot-end components.The preparation of the MoSi_(2)-Gd_(2)Zr_(2)O_(7)dual-layer TB...Dual-layer thermal barrier coatings(TBCs)with ultrahigh temperature resistance were prepared on the surface of molybdenum-rhenium alloy hot-end components.The preparation of the MoSi_(2)-Gd_(2)Zr_(2)O_(7)dual-layer TBCs was designed based on the coefficient of thermal expansion and the coating functionality,and it was completed using atmospheric plasma spraying technique.The microstructure,mechanical properties,and thermal properties were analyzed.Results indicate that the adhesion of the prepared dual-layer composite TBCs is excellent,and no noticeable cracks appear at the interface.Compared with the MoSi_(2)coating with a low fracture toughness(0.88 MPa·m^(1/2)),the Gd_(2)Zr_(2)O_(7)coating exhibits higher fracture toughness(1.74 MPa·m^(1/2))and stronger resistance to crack propagation.The prepared MoSi_(2)-Gd_(2)Zr_(2)O_(7)composite coatings have a high porosity(39%),low thermal conductivity(1.020 W·(m·K)^(−1),1200℃),and low thermal diffusivity(0.249 mm^(2)/s,1200℃).Additionally,they possess a high oxygen-vacancy concentration,which ensures excellent insulation performance.展开更多
Space-Based Solar Power(SBSP) presents a promising solution for achieving carbon neutrality and Renewable Electricity 100%(RE100) goals by offering a stable and continuous energy supply. However, its commercialization...Space-Based Solar Power(SBSP) presents a promising solution for achieving carbon neutrality and Renewable Electricity 100%(RE100) goals by offering a stable and continuous energy supply. However, its commercialization faces significant obstacles due to the technical challenges of long-distance microwave Wireless Power Transmission(WPT) from geostationary orbit. Even ground-based kilometer-scale WPT experiments remain difficult because of limited testing infrastructure, high costs, and strict electromagnetic wave regulations. Since the 1975 NASA-Raytheon experiment, which successfully recovered 30 kW of power over 1.55 km, there has been little progress in extending the transmission distance or increasing the retrieved power. This study proposes a cost-effective methodology for conducting long-range WPT experiments in constrained environments by utilizing existing infrastructure. A deep space antenna operating at 2.08 GHz with an output power of 2.3 kW and a gain of 55.3 dBi was used as the transmitter. Two test configurations were implemented: a 1.81 km ground-to-air test using an aerostat to elevate the receiver and a 1.82 km ground-to-ground test using a ladder truck positioned on a plateau. The rectenna consists of a lightweight 3×3 patch antenna array(0.9 m × 0.9 m), accompanied by a steering device and LED indicators to verify power reception. The aerostat-based test achieved a power density of 154.6 mW/m2, which corresponds to approximately 6.2% of the theoretical maximum. The performance gap is primarily attributed to near-field interference, detuning of the patch antenna, rectifier mismatch, and alignment issues. These limitations are expected to be mitigated through improved patch antenna fabrication, a transition from GaN to GaAs rectifiers optimized for lower input power, and the implementation of an automated alignment system. With these enhancements, the recovered power is expected to improve by approximately four to five times. The results demonstrate a practical and scalable framework for long-range WPT experiments under constrained conditions and provide key insights for advancing SBSP technology.展开更多
Spinal cord injury represents a severe form of central nervous system trauma for which effective treatments remain limited.Microglia is the resident immune cells of the central nervous system,play a critical role in s...Spinal cord injury represents a severe form of central nervous system trauma for which effective treatments remain limited.Microglia is the resident immune cells of the central nervous system,play a critical role in spinal cord injury.Previous studies have shown that microglia can promote neuronal survival by phagocytosing dead cells and debris and by releasing neuroprotective and anti-inflammatory factors.However,excessive activation of microglia can lead to persistent inflammation and contribute to the formation of glial scars,which hinder axonal regeneration.Despite this,the precise role and mechanisms of microglia during the acute phase of spinal cord injury remain controversial and poorly understood.To elucidate the role of microglia in spinal cord injury,we employed the colony-stimulating factor 1 receptor inhibitor PLX5622 to deplete microglia.We observed that sustained depletion of microglia resulted in an expansion of the lesion area,downregulation of brain-derived neurotrophic factor,and impaired functional recovery after spinal cord injury.Next,we generated a transgenic mouse line with conditional overexpression of brain-derived neurotrophic factor specifically in microglia.We found that brain-derived neurotrophic factor overexpression in microglia increased angiogenesis and blood flow following spinal cord injury and facilitated the recovery of hindlimb motor function.Additionally,brain-derived neurotrophic factor overexpression in microglia reduced inflammation and neuronal apoptosis during the acute phase of spinal cord injury.Furthermore,through using specific transgenic mouse lines,TMEM119,and the colony-stimulating factor 1 receptor inhibitor PLX73086,we demonstrated that the neuroprotective effects were predominantly due to brain-derived neurotrophic factor overexpression in microglia rather than macrophages.In conclusion,our findings suggest the critical role of microglia in the formation of protective glial scars.Depleting microglia is detrimental to recovery of spinal cord injury,whereas targeting brain-derived neurotrophic factor overexpression in microglia represents a promising and novel therapeutic strategy to enhance motor function recovery in patients with spinal cord injury.展开更多
A series of blue and blue‑green Ir(Ⅲ)complexes has been investigated theoretically to explore their electronic structures,photophysical properties,efficiency roll‑off effect,and thermal activation delayed fluorescenc...A series of blue and blue‑green Ir(Ⅲ)complexes has been investigated theoretically to explore their electronic structures,photophysical properties,efficiency roll‑off effect,and thermal activation delayed fluorescence(TADF)properties.All calculations were performed using density functional theory(DFT)and time‑dependent density functional theory(TDDFT).Calculations for electronic structures,frontier molecular orbital characteristics(which determine the efficiency roll‑off effect of the complexes),and photophysical properties were conducted using the Gaussian 09 software package.The calculation of spin‑orbit coupling matrix elements<T|HSOC|S>,which determine the TADF properties of the complexes,was performed using the ORCA software package.The calculation results show that the auxiliary ligand tetraphenylimidodiphosphinate(tpip),a strong electron‑withdrawing group,can mitigate the efficiency roll‑off effect of the complex.Furthermore,TADF is observed in one of the designed complexes,(F_(3)Phppy)_(2)Ir(tpip),where F_(3)Phppy=2‑[4‑(2,4,6‑trifluorophenyl)phenyl]pyridine.展开更多
Coulomb drag refers to the phenomenon in which a current driven through one conducting layer induces a voltage nearby,electrically isolated layer sorely through interlayer Coulomb interactions between charge carriers....Coulomb drag refers to the phenomenon in which a current driven through one conducting layer induces a voltage nearby,electrically isolated layer sorely through interlayer Coulomb interactions between charge carriers.It has been extensively studied in various systems,including parallel nanowires,double quantum wells,and double-layer graphene.Here,we report the observation of Coulomb drag in a novel system consisting of two graphene layers separated laterally by a 30 nm gap within the material plane,exhibiting behavior distinct from that in vertical graphene heterostructures.Our experiments reveal pronounced negative drag resistances under an out-of-plane magnetic field at the quantum Hall edges,reaching a maximum when the carrier densities in both graphene layers are tuned to the charge neutrality point via gate voltages.Our work establish two separate and spatially closed quantum Hall edge modes as a new platform to explore electronic interaction physics between one dimensional systems.展开更多
基金funded the Ecuadorian National Secretary of Higher Education,Science and Technology(SENESCYT),through the Scholarship Programme 2012.
文摘Climate change has well-documented psychological consequences for society.However,the emotional experiences of frontline conservation professionals remain underexplored.As key knowledge producers and participants in decision-making processes,conservation researchers play a crucial role in shaping and implementing adaptation and mitigation efforts,which are pivotal for effective climate planning.Understanding their emotional responses is essential for enhancing the success of these strategies and supporting climate action.This study aims to identify the most prevalent emotions experienced by conservation researchers regarding climate change across various countries and to examine the qualitative and quantitative factors shaping these emotions.An online survey was conducted with 362 participants from 98 academic and research institutions,utilising both closed and open-ended questions to capture demographic data,climate knowledge,stances on mitigation and adaptation,and emotional responses.Data analysis revealed that feelings of powerlessness,guilt,and concern were most frequently reported,driven by a profound sense of inability to halt climate change,frustration with perceived inaction by governments and industries,and self-assessed personal shortcomings.Age and stances on climate adaptation were identified as primary factors influencing emotional responses,particularly among individuals aged 20–50 and 61–70,with opposition to adaptation correlating with stronger emotional reactions.Demographic factors such as region,place of residence,and mitigation stances played a minor role.These findings provide valuable insights into the psychological well-being of conservation researchers related to climate change.
文摘Purpose:Diaspora researchers work in one country but have ancestral origins in another,either through moves during a research career(mobile diaspora researchers)or by starting research in the target country(embedded diaspora researchers).Whilst mobile researchers might be tracked through affiliation changes in bibliometric databases,embedded researchers cannot.This article reports an evidence-based discussion of which countries’diaspora researchers can be partially tracked using first or last names,addressing this limitation.Design/methodology/approach:A frequency analysis of first and last names of authors of all Scopus journal articles 2001-2021 for 200 countries or regions.Findings:There are great variations in the extent to which first or last names are uniquely national,from Monserrat(no unique first names)to Thailand(81%unique last names).Nevertheless,most countries have a subset of first or last names that are relatively unique.For the 50 countries with the most researchers,authors with relatively national names are always more likely to research their name-associated country,suggesting a continued national association.Lists of researchers’first and last name frequencies and proportions are provided for 200 countries/regions.Research limitations:Only one period is tracked(2001-2021)and no attempt was made to validate the ancestral origins of any researcher.Practical implications:Simple name heuristics can be used to identify the international spread of a sample of most countries’diaspora researchers,but some manual checks of individual names are needed to weed out false matches.This can supplement mobile researcher data from bibliometric databases.Originality/value:This is the first attempt to list name associations for the authors of all countries and large regions,and to identify the countries for which diaspora researchers could be tracked by name.
基金the Research Council of Norway,grant number 256223(the R-QUEST centre)。
文摘Purpose:The ranking lists of highly cited researchers receive much public attention.In common interpretations,highly cited researchers are perceived to have made extraordinary contributions to science.Thus,the metrics of highly cited researchers are often linked to notions of breakthroughs,scientific excellence,and lone geniuses.Design/methodology/approach:In this study,we analyze a sample of individuals who appear on Clarivate Analytics’Highly Cited Researchers list.The main purpose is to juxtapose the characteristics of their research performance against the claim that the list captures a small fraction of the researcher population that contributes disproportionately to extending the frontier and gaining—on behalf of society—knowledge and innovations that make the world healthier,richer,sustainable,and more secure.Findings:The study reveals that the highly cited articles of the selected individuals generally have a very large number of authors.Thus,these papers seldom represent individual contributions but rather are the result of large collective research efforts conducted in research consortia.This challenges the common perception of highly cited researchers as individual geniuses who can be singled out for their extraordinary contributions.Moreover,the study indicates that a few of the individuals have not even contributed to highly cited original research but rather to reviews or clinical guidelines.Finally,the large number of authors of the papers implies that the ranking list is very sensitive to the specific method used for allocating papers and citations to individuals.In the"whole count"methodology applied by Clarivate Analytics,each author gets full credit of the papers regardless of the number of additional co-authors.The study shows that the ranking list would look very different using an alternative fractionalised methodology.Research limitations:The study is based on a limited part of the total population of highly cited researchers.Practical implications:It is concluded that"excellence"understood as highly cited encompasses very different types of research and researchers of which many do not fit with dominant preconceptions.Originality/value:The study develops further knowledge on highly cited researchers,addressing questions such as who becomes highly cited and the type of research that benefits by defining excellence in terms of citation scores and specific counting methods.
文摘Opening a new scientific frontier lying under the Antarctic ice, Russian researchers have drilled down and finally reached the surface of the gigantic freshwater lake, Lake Vostok. The mission chief likened the achievement to placing a man on the moon. Drilling in the area of the lake began 22 years ago in 1990, but progressed slowly as a result of funding shortages, equipment breakdowns, difficulties of drilling in the ＂warm＂ ice, and environmental concerns. In 1996, six years after drilling was started, a group of Russian and British scientists discovered the lake believed to be one of the largest fresh water reservoirs on the planet. This lake is among the last unexplored places on Earth. Sealed from the Earth＇s atmosphere for millions of years, it may provide vital information about microbial evolution, the past climate of the Earth, and the formation of the Antarctic ice sheet. Russian experts waited several years for international approval of their drilling technology before proceeding. As anticipated, lake water under pressure rushed up the borehole, pushing the drilling fluid up and away, then froze, forming a protective plug that prevented contamination of the lake. In December of the next Antarctic season, 2012--2013, researchers plan to re-drill the frozen sample of subglacial water for analysis.
文摘Gene deletion has been a valuable tool for unraveling the mysteries of molecular biology.Early approaches included gene trapping and gene targetting to disrupt or delete a gene randomly or at a specific location,respectively.Using these technologies in mouse embryos led to the generation of mouse knocko ut models and many scientific discoveries.The efficacy and specificity of these approaches have significantly increased with the advent of new technology such as cluste red regula rly inters paced short palindromic repeats for targetted gene deletion.However,several limitations including unwanted off-target gene deletion have hindered their widespread use in the field.Crerecombinase technology has provided additional capacity for cell-specific gene deletion.In this review,we provide a summary of currently available literature on the application of this system for targetted deletion of neuronal genes.This article has been constructed to provide some background info rmation for the new trainees on the mechanism and to provide necessary information for the design,and application of the Cre-recombinase system thro ugh reviewing the most f requent promoters that are currently available for genetic manipulation of neuro ns.We additionally will provide a summary of the latest technological developments that can be used for targeting neurons.This may also serve as a general guide for the selection of appropriate models for biomedical research.
文摘Lanthanide(Ln^(3+))-doped photon avalanche(PA)upconversion nanoparticles(UCNPs)have great prospects in many frontier applications,such as super-resolution bioimaging,miniaturized lasers,single-molecule tracking,and quantum optics.However,it remains challenging to realize PA in colloidal Ln^(3+)-doped UCNPs at room temperature(RT),due to the deleterious quenching effect associated with the surface and lattice OH^(-)defects.
文摘This paper focuses on the remarkable contributions and achievements of Dr.Azar Andami(1926–1984),a renowned physician and specialist at the Pasteur Institute of Iran.Dr.Andami conducted extensive research on infectious diseases,particularly cholera,utilizing her knowledge in medicine,bacteriology,and laboratory sciences.She played a crucial role in the mass production of the cholera vaccine at the Pasteur Institute of Iran and in controlling the spread of communicable diseases both locally and globally.This paper aims to highlight her remarkable works and accomplishments.
基金supported by the National Social Science Foundation of China(Grant No.:11BTQ044)
文摘Purpose:This study was carried out to uncover the characteristics of information seeking behavior of researchers as faculty/student team members.Design/methodology/approach:An inventory encompassing 6 dimensions of information seeking behavior was developed:Information awareness,information acquisition,information evaluation,information organization and management,information utilization and information ethics.Data was collected on 306 respondents from 52 faculty/student teams in Central South University in China and analyzed using SPSS 18.0 software.Findings:Significant differences were found among researchers with different genders in information awareness and in different academic disciplines in information acquisition and information utilization.The survey shows the characteristics of information seeking behavior of different gender groups and different teams:1) male participants got higher scores in all of the 6 dimensions of information seeking behavior;2) small teams performed best,followed by middle-sized teams and large teams;3) faculty/doctoral student teams possessed better information seeking skills than faculty/master’s student teams or faculty/doctoral and master’s student teams:4) medical teams achieved the highest level in all of the 6 dimensions of information seeking behavior,whereas natural science teams the lowest level.Medical and engineering teams were rated higher than other teams in information acquisition and information utilization.Research limitations:The small population size and doctoral students accounting for only a small portion of the respondents in the sample limit the generalization of our findings.Practical implications:The findings of this study have some implications for research and practice,especially for educational institutions,library science and information literacy training.Originality/value:This paper is the first to describe and analyze the characteristics of information seeking behavior of researchers as faculty/student team members.
文摘为探究节水灌溉以及品种类型对再生稻产量和稻米品质的影响,2023年在湖北蕲春和浠水开展大田试验。以3个节水抗旱稻品种(旱优8200、旱优116和旱优73)和3个优质稻品种(箴两优郢香丝苗、荃优粤农丝苗和荃优607)为供试材料,以湖北省再生稻大面积种植的普通水稻品种(两优6326)为对照,设置常规灌溉和节水灌溉2种水分管理方式,分析再生稻模式下不同品种产量和稻米品质对水分管理的响应差异。结果表明,相较于常规灌溉,节水灌溉处理使头季和再生季灌水量分别平均减少76%和85%,但产量和稻米的加工、外观和蒸煮食味品质在水分处理间无显著差异,且这一结果在不同试验地点间保持一致。这表明,与常规灌溉相比,节水抗旱稻和优质稻品种在节水灌溉条件下均能保持较为稳定的头季和再生季产量和稻米品质。优质稻头季和再生季产量分别为8.54 t hm^(-2)和5.88 t hm^(-2),相较于普通水稻产量差异不显著;但头季和再生季整精米率分别显著提高13.5个百分点和20.6个百分点,垩白粒率和垩白度分别显著降低22.6个百分点和6.4个百分点、10.8个百分点和1.8个百分点。节水抗旱稻在头季的产量以及稻米加工、外观和蒸煮食味品质方面与普通水稻无显著差异,但在再生季,产量显著下降17%,整精米率显著提高17.0个百分点,垩白粒率和垩白度分别降低5.5个百分点和1.0个百分点。在同一品种类型中,再生稻产量和稻米品质存在显著的品种间差异。相关性分析表明,再生季稻米的加工、外观和蒸煮食味品质指标均与头季相应指标呈正相关。因此,在降水条件较好的地区,结合优良水稻品种,实施“以雨养为主、关键生育期适时灌溉”的节水灌溉策略,可有效降低水分消耗、提升水分利用效率,同时实现再生稻的高产与优质目标。
基金supported by the Natural Science Foundation of Yunnan Province,No.202401AS070086(to ZW)the National Key Research and Development Program of China,No.2018YFA0801403(to ZW)+1 种基金Yunnan Science and Technology Talent and Platform Plan,No.202105AC160041(to ZW)the Natural Science Foundation of China,No.31960120(to ZW)。
文摘Traumatic brain injury can be categorized into primary and secondary injuries.Secondary injuries are the main cause of disability following traumatic brain injury,which involves a complex multicellular cascade.Microglia play an important role in secondary injury and can be activated in response to traumatic brain injury.In this article,we review the origin and classification of microglia as well as the dynamic changes of microglia in traumatic brain injury.We also clarify the microglial polarization pathways and the therapeutic drugs targeting activated microglia.We found that regulating the signaling pathways involved in pro-inflammatory and anti-inflammatory microglia,such as the Toll-like receptor 4/nuclear factor-kappa B,mitogen-activated protein kinase,Janus kinase/signal transducer and activator of transcription,phosphoinositide 3-kinase/protein kinase B,Notch,and high mobility group box 1 pathways,can alleviate the inflammatory response triggered by microglia in traumatic brain injury,thereby exerting neuroprotective effects.We also reviewed the strategies developed on the basis of these pathways,such as drug and cell replacement therapies.Drugs that modulate inflammatory factors,such as rosuvastatin,have been shown to promote the polarization of antiinflammatory microglia and reduce the inflammatory response caused by traumatic brain injury.Mesenchymal stem cells possess anti-inflammatory properties,and clinical studies have confirmed their significant efficacy and safety in patients with traumatic brain injury.Additionally,advancements in mesenchymal stem cell-delivery methods—such as combinations of novel biomaterials,genetic engineering,and mesenchymal stem cell exosome therapy—have greatly enhanced the efficiency and therapeutic effects of mesenchymal stem cells in animal models.However,numerous challenges in the application of drug and mesenchymal stem cell treatment strategies remain to be addressed.In the future,new technologies,such as single-cell RNA sequencing and transcriptome analysis,can facilitate further experimental studies.Moreover,research involving non-human primates can help translate these treatment strategies to clinical practice.
基金supported by the National Key R&D Program of China,No.2021YFC2501200(to PC).
文摘Short-chain fatty acids,metabolites produced by the fermentation of dietary fiber by gut microbiota,have garnered significant attention due to their correlation with neurodegenerative diseases,particularly Parkinson’s disease.In this review,we summarize the changes in short-chain fatty acid levels and the abundance of short-chain fatty acid-producing bacteria in various samples from patients with Parkinson’s disease,highlighting the critical role of gut homeostasis imbalance in the pathogenesis and progression of the disease.Focusing on the nervous system,we discuss the molecular mechanisms by which short-chain fatty acids influence the homeostasis of both the enteric nervous system and the central nervous system.We identify key processes,including the activation of G protein-coupled receptors and the inhibition of histone deacetylases by short-chain fatty acids.Importantly,structural or functional disruptions in the enteric nervous system mediated by these fatty acids may lead to abnormalα-synuclein expression and gastrointestinal dysmotility,which could serve as an initiating event in Parkinson’s disease.Furthermore,we propose that short-chain fatty acids help establish communication between the enteric nervous system and the central nervous system via the vagal nerve,immune circulation,and endocrine signaling.This communication may shed light on their potential role in the transmission ofα-synuclein from the gut to the brain.Finally,we elucidate novel treatment strategies for Parkinson’s disease that target short-chain fatty acids and examine the challenges associated with translating short-chain fatty acid-based therapies into clinical practice.In conclusion,this review emphasizes the pivotal role of short-chain fatty acids in regulating gut-brain axis integrity and their significance in the pathogenesis of Parkinson’s disease from the perspective of the nervous system.Moreover,it highlights the potential value of short-chain fatty acids in early intervention for Parkinson’s disease.Future research into the molecular mechanisms of short-chain fatty acids and their synergistic interactions with other gut metabolites is likely to advance the clinical translation of innovative short-chain fatty acid-based therapies for Parkinson’s disease.
基金supported by the National Science Foundation of China,Nos.82325031(to FX),82030059(to YC),82102290(to YG),U23A20485(to YC)Noncommunicable Chronic Diseases-National Science and Technology Major Project,No.2023ZD0505504(to FX),2023ZD0505500(to YC)the Key R&D Program of Shandong Province,No.2022ZLGX03(to YC).
文摘Global brain ischemia and neurological deficit are consequences of cardiac arrest that lead to high mortality.Despite advancements in resuscitation science,our limited understanding of the cellular and molecular mechanisms underlying post-cardiac arrest brain injury have hindered the development of effective neuroprotective strategies.Previous studies primarily focused on neuronal death,potentially overlooking the contributions of non-neuronal cells and intercellular communication to the pathophysiology of cardiac arrest-induced brain injury.To address these gaps,we hypothesized that single-cell transcriptomic analysis could uncover previously unidentified cellular subpopulations,altered cell communication networks,and novel molecular mechanisms involved in post-cardiac arrest brain injury.In this study,we performed a single-cell transcriptomic analysis of the hippocampus from pigs with ventricular fibrillation-induced cardiac arrest at 6 and 24 hours following the return of spontaneous circulation,and from sham control pigs.Sequencing results revealed changes in the proportions of different cell types,suggesting post-arrest disruption in the blood-brain barrier and infiltration of neutrophils.These results were validated through western blotting,quantitative reverse transcription-polymerase chain reaction,and immunofluorescence staining.We also identified and validated a unique subcluster of activated microglia with high expression of S100A8,which increased over time following cardiac arrest.This subcluster simultaneously exhibited significant M1/M2 polarization and expressed key functional genes related to chemokines and interleukins.Additionally,we revealed the post-cardiac arrest dysfunction of oligodendrocytes and the differentiation of oligodendrocyte precursor cells into oligodendrocytes.Cell communication analysis identified enhanced post-cardiac arrest communication between neutrophils and microglia that was mediated by neutrophil-derived resistin,driving pro-inflammatory microglial polarization.Our findings provide a comprehensive single-cell map of the post-cardiac arrest hippocampus,offering potential novel targets for neuroprotection and repair following cardiac arrest.
文摘A recently published study(Xin et al.,Prog Biochem Biophys,2026,53(2):431-441.DOI:10.3724/j.pibb.2025.0508)addresses the therapeutic challenges of pancreatic ductal adenocarcinoma(PDAC)by innovatively developing an orally administered nanogene delivery system.Designed to achieve in situ,efficient delivery of chimeric antigen receptor(CAR)genes to tumor sites,this approach offers a novel strategy for CAR-macrophage(CAR-M)based immunotherapy.Its key highlights are as follows.
文摘Noncohesive particle clusters are identified and tracked in turbulent flows to determine the breakdown and time evolution of cluster statistics and their implications for interscale mass transfer,which has connections to the classical turbulent energy cascade and its mass cascade counterpart running in parallel.In particular,the formation and dynamics of sediment and larvae clusters are of interest to coral larvae settlement in coastal regions and particularly the resilience of green-gray coastal protection solutions.Analogous cluster behavior is relevant to cloud microphysics and precipitation initiation,radiation transport and light transmission through colloids and suspensions,heat and mass transfer in particle-laden flows,and viral and pollutant transmission.Following a comparison between various clustering techniques,we adopt a density-based cluster identification algorithm based on its simplicity and efficiency,where particles are clustered based on the number of neighboring particles in their individual spheres of influence.We establish parallels with lattice-based percolation theory,as evident in the power-law scaling of the cluster size distribution near the percolation threshold.The degree of discontinuity of the phase transition associated with this percolation threshold is observed to broaden with larger Stokes numbers and thereby large-scale clustering.The sensitivity of our findings to the employed clustering algorithm is discussed.A novel cluster tracking algorithm is deployed to determine the interscale transfer rate along the particle-number phase-space dimension via accounting of cluster breakup and merger events,extending previous work on the bubble breakup cascade beneath surface breaking waves.Our findings shed light on the interaction between particle clusters and their carrier turbulent flows,with an eye toward transport models incorporating cluster characteristics and dynamics.
文摘39 soil samples surrounding a lead-zinc mining area in Guangxi were collected,and the contents of Pb,Hg,Cd,Cr,As,Cu,Zn,and Ni were determined to investigate the pollution characteristics and sources of heavy metals.ArcGIS inverse distance weight difference method was used to analyze the characteristics of pollution distribution,and single-factor pollution index,Nemerow comprehensive pollution index,ground accumulation index,and potential ecological risk index were selected to evaluate the characteristics of heavy metal pollution.Based on correlation analysis,the absolute principal component-multiple linear regression(APCS-MLR)and positive definite matrix factorization(PMF)models were used to analyze the sources of soil heavy metals.The results showed that the average concentrations of all eight heavy metals exceeded both national and Guangxi soil background values.Hg,Cd,and Zn exhibited high variation(greater than 0.5),indicating significant external disturbances,and their spatial distribution was closely related to mining activity locations.The single-factor pollution index evaluation indicated varying degrees of pollution risk for Cd,Zn,and As,with Cd and Zn being the most severe pollutants,as 69.23%and 30.77%of the samples fell into the moderate pollution or higher category.The geoaccumulation index analysis ranked the mean pollution levels of the eight elements as follows:Zn>Cd>Ni>Pb>Cu>Cr>Hg>As,with Cd and Zn showing the most severe contamination,and 51.28%of the samples exhibiting moderate or higher pollution levels.The Nemerow comprehensive pollution index evaluation showed that 74.35%of soil samples were classified as moderate to heavy pollution.The potential ecological risk index assessment indicated significant ecological risks posed by Cd and Zn,with 82.05%and 5.12%of the samples classified as causing strong to extreme ecological risks,respectively.The source apportionment analysis revealed minor differences between the two models.The APCS-MLR model identified three pollution sources and their contribution rates:anthropogenic mining sources(31.13%),parent material sources(40.38%),and unidentified sources(28.49%).The PMF model identified three pollution sources with contribution rates of anthropogenic mining sources(26.10%),parent material sources(46.96%),and a combined traffic and agricultural source(26.61%).Pb,Hg,Cd,and Zn mainly originated from mining activities;Cr,As,and Ni were primarily derived from the parent material,while Cu was predominantly attributed to traffic and agricultural sources.These findings provide a scientific basis for the prevention and control of heavy metal pollution in mining areas.
基金Supported by Scientific and Technological Innovation of Shaanxi Provincial State-Owned Capital Operation Budget(2022-056)Institute's Self-Developed Technology Program(0801YK2317)+4 种基金Qin Chuangyuan Cites High-Level Innovation and Entrepreneurship Talent Program(QCYRCXM-2023-120)Qin Chuangyuan Industry Cluster Zone“Four Chains”Integration Program(2024CY-JJQ-46)National Natural Science Foundation of China(52071274)Key Research and Development Projects of Shaanxi Province(2023-YBGY-442)Science and Technology Nova Project-Innovative Talent Promotion Program of Shaanxi Province(2020KJXX-062)。
文摘Dual-layer thermal barrier coatings(TBCs)with ultrahigh temperature resistance were prepared on the surface of molybdenum-rhenium alloy hot-end components.The preparation of the MoSi_(2)-Gd_(2)Zr_(2)O_(7)dual-layer TBCs was designed based on the coefficient of thermal expansion and the coating functionality,and it was completed using atmospheric plasma spraying technique.The microstructure,mechanical properties,and thermal properties were analyzed.Results indicate that the adhesion of the prepared dual-layer composite TBCs is excellent,and no noticeable cracks appear at the interface.Compared with the MoSi_(2)coating with a low fracture toughness(0.88 MPa·m^(1/2)),the Gd_(2)Zr_(2)O_(7)coating exhibits higher fracture toughness(1.74 MPa·m^(1/2))and stronger resistance to crack propagation.The prepared MoSi_(2)-Gd_(2)Zr_(2)O_(7)composite coatings have a high porosity(39%),low thermal conductivity(1.020 W·(m·K)^(−1),1200℃),and low thermal diffusivity(0.249 mm^(2)/s,1200℃).Additionally,they possess a high oxygen-vacancy concentration,which ensures excellent insulation performance.
文摘Space-Based Solar Power(SBSP) presents a promising solution for achieving carbon neutrality and Renewable Electricity 100%(RE100) goals by offering a stable and continuous energy supply. However, its commercialization faces significant obstacles due to the technical challenges of long-distance microwave Wireless Power Transmission(WPT) from geostationary orbit. Even ground-based kilometer-scale WPT experiments remain difficult because of limited testing infrastructure, high costs, and strict electromagnetic wave regulations. Since the 1975 NASA-Raytheon experiment, which successfully recovered 30 kW of power over 1.55 km, there has been little progress in extending the transmission distance or increasing the retrieved power. This study proposes a cost-effective methodology for conducting long-range WPT experiments in constrained environments by utilizing existing infrastructure. A deep space antenna operating at 2.08 GHz with an output power of 2.3 kW and a gain of 55.3 dBi was used as the transmitter. Two test configurations were implemented: a 1.81 km ground-to-air test using an aerostat to elevate the receiver and a 1.82 km ground-to-ground test using a ladder truck positioned on a plateau. The rectenna consists of a lightweight 3×3 patch antenna array(0.9 m × 0.9 m), accompanied by a steering device and LED indicators to verify power reception. The aerostat-based test achieved a power density of 154.6 mW/m2, which corresponds to approximately 6.2% of the theoretical maximum. The performance gap is primarily attributed to near-field interference, detuning of the patch antenna, rectifier mismatch, and alignment issues. These limitations are expected to be mitigated through improved patch antenna fabrication, a transition from GaN to GaAs rectifiers optimized for lower input power, and the implementation of an automated alignment system. With these enhancements, the recovered power is expected to improve by approximately four to five times. The results demonstrate a practical and scalable framework for long-range WPT experiments under constrained conditions and provide key insights for advancing SBSP technology.
基金supported by the National Natural Science Foundation of China,Nos.82072165 and 82272256(both to XM)the Key Project of Xiangyang Central Hospital,No.2023YZ03(to RM)。
文摘Spinal cord injury represents a severe form of central nervous system trauma for which effective treatments remain limited.Microglia is the resident immune cells of the central nervous system,play a critical role in spinal cord injury.Previous studies have shown that microglia can promote neuronal survival by phagocytosing dead cells and debris and by releasing neuroprotective and anti-inflammatory factors.However,excessive activation of microglia can lead to persistent inflammation and contribute to the formation of glial scars,which hinder axonal regeneration.Despite this,the precise role and mechanisms of microglia during the acute phase of spinal cord injury remain controversial and poorly understood.To elucidate the role of microglia in spinal cord injury,we employed the colony-stimulating factor 1 receptor inhibitor PLX5622 to deplete microglia.We observed that sustained depletion of microglia resulted in an expansion of the lesion area,downregulation of brain-derived neurotrophic factor,and impaired functional recovery after spinal cord injury.Next,we generated a transgenic mouse line with conditional overexpression of brain-derived neurotrophic factor specifically in microglia.We found that brain-derived neurotrophic factor overexpression in microglia increased angiogenesis and blood flow following spinal cord injury and facilitated the recovery of hindlimb motor function.Additionally,brain-derived neurotrophic factor overexpression in microglia reduced inflammation and neuronal apoptosis during the acute phase of spinal cord injury.Furthermore,through using specific transgenic mouse lines,TMEM119,and the colony-stimulating factor 1 receptor inhibitor PLX73086,we demonstrated that the neuroprotective effects were predominantly due to brain-derived neurotrophic factor overexpression in microglia rather than macrophages.In conclusion,our findings suggest the critical role of microglia in the formation of protective glial scars.Depleting microglia is detrimental to recovery of spinal cord injury,whereas targeting brain-derived neurotrophic factor overexpression in microglia represents a promising and novel therapeutic strategy to enhance motor function recovery in patients with spinal cord injury.
文摘A series of blue and blue‑green Ir(Ⅲ)complexes has been investigated theoretically to explore their electronic structures,photophysical properties,efficiency roll‑off effect,and thermal activation delayed fluorescence(TADF)properties.All calculations were performed using density functional theory(DFT)and time‑dependent density functional theory(TDDFT).Calculations for electronic structures,frontier molecular orbital characteristics(which determine the efficiency roll‑off effect of the complexes),and photophysical properties were conducted using the Gaussian 09 software package.The calculation of spin‑orbit coupling matrix elements<T|HSOC|S>,which determine the TADF properties of the complexes,was performed using the ORCA software package.The calculation results show that the auxiliary ligand tetraphenylimidodiphosphinate(tpip),a strong electron‑withdrawing group,can mitigate the efficiency roll‑off effect of the complex.Furthermore,TADF is observed in one of the designed complexes,(F_(3)Phppy)_(2)Ir(tpip),where F_(3)Phppy=2‑[4‑(2,4,6‑trifluorophenyl)phenyl]pyridine.
基金support from the National Key Projects for Research and Development of China(Grant Nos.2022YFA1204700,2021YFA1400400)National Natural Science Foundation of China(Grant No.12525403)+3 种基金Natural Science Foundation of Jiangsu Province(Grant Nos.BK20220066,BK20233001)Program for Innovative Talents and Entrepreneur in Jiangsu(Grant No.JSSCTD202101)support from the JSPS KAKENHI(Grant Numbers 21H05233 and 23H02052)World Premier International Research Center Initiative(WPI),MEXT,Japan.
文摘Coulomb drag refers to the phenomenon in which a current driven through one conducting layer induces a voltage nearby,electrically isolated layer sorely through interlayer Coulomb interactions between charge carriers.It has been extensively studied in various systems,including parallel nanowires,double quantum wells,and double-layer graphene.Here,we report the observation of Coulomb drag in a novel system consisting of two graphene layers separated laterally by a 30 nm gap within the material plane,exhibiting behavior distinct from that in vertical graphene heterostructures.Our experiments reveal pronounced negative drag resistances under an out-of-plane magnetic field at the quantum Hall edges,reaching a maximum when the carrier densities in both graphene layers are tuned to the charge neutrality point via gate voltages.Our work establish two separate and spatially closed quantum Hall edge modes as a new platform to explore electronic interaction physics between one dimensional systems.
