Magnesium(Mg)alloys are considered to be a new generation of revolutionary medical metals.Laser-beam powder bed fusion(PBF-LB)is suitable for fabricating metal implants withpersonalized and complicated structures.Howe...Magnesium(Mg)alloys are considered to be a new generation of revolutionary medical metals.Laser-beam powder bed fusion(PBF-LB)is suitable for fabricating metal implants withpersonalized and complicated structures.However,the as-built part usually exhibits undesirable microstructure and unsatisfactory performance.In this work,WE43 parts were firstly fabricated by PBF-LB and then subjected to heat treatment.Although a high densification rate of 99.91%was achieved using suitable processes,the as-built parts exhibited anisotropic and layeredmicrostructure with heterogeneously precipitated Nd-rich intermetallic.After heat treatment,fine and nano-scaled Mg24Y5particles were precipitated.Meanwhile,theα-Mg grainsunderwent recrystallization and turned coarsened slightly,which effectively weakened thetexture intensity and reduced the anisotropy.As a consequence,the yield strength and ultimate tensile strength were significantly improved to(250.2±3.5)MPa and(312±3.7)MPa,respectively,while the elongation was still maintained at a high level of 15.2%.Furthermore,the homogenized microstructure reduced the tendency of localized corrosion and favoredthe development of uniform passivation film.Thus,the degradation rate of WE43 parts was decreased by an order of magnitude.Besides,in-vitro cell experiments proved their favorable biocompatibility.展开更多
Biomedical magnesium(Mg)alloys have garnered significant attention because of their unique biodegradability,favorable biocompatibility,and suitable mechanical properties.The incorporation of rare earth(RE)elements,wit...Biomedical magnesium(Mg)alloys have garnered significant attention because of their unique biodegradability,favorable biocompatibility,and suitable mechanical properties.The incorporation of rare earth(RE)elements,with their distinct physical and chemical properties,has greatly contributed to enhancing the mechanical performance,degradation behavior,and biological performance of biomedical Mg alloys.Currently,a series of RE-Mg alloys are being designed and investigated for orthopedic implants and cardiovascular stents,achieving substantial and encouraging research progress.In this work,a comprehensive summary of the state-of-the-art in biomedical RE-Mg alloys is provided.The physiological effects and design standards of RE elements in biomedical Mg alloys are discussed.Particularly,the degradation behavior and mechanical properties,including their underlying action are studied in-depth.Furthermore,the preparation techniques and current application status of RE-Mg alloys are reviewed.Finally,we address the ongoing challenges and propose future prospects to guide the development of high-performance biomedical Mg-RE alloys.展开更多
Dielectric barrier discharge(DBD)is considered as a promising technique to produce large volume uniform plasma at atmospheric pressure,and the dielectric barrier layer between the electrodes plays a key role in the DB...Dielectric barrier discharge(DBD)is considered as a promising technique to produce large volume uniform plasma at atmospheric pressure,and the dielectric barrier layer between the electrodes plays a key role in the DBD processes and enhancing discharge uniformity.In this work,the uniformity and discharge characteristics of the nanosecond(ns)pulsed DBD with dielectric barrier layers made of alumina,quartz glass,polycarbonate(PC),and polypropylene(PP)are investigated via discharge image observation,voltage-current waveform measurement and optical emission spectral diagnosis.Through analyzing discharge image by gray value standard deviation method,the discharge uniformity is quantitatively calculated.The effects of the space electric field intensity,the electron density(Ne),and the space reactive species on the uniformity are studied with quantifying the gap voltage Ug and the discharge current Ig,analyzing the recorded optical emission spectra,and simulating the temporal distribution of Ne with a one-dimensional fluid model.It is found that as the relative permittivity of the dielectric materials increases,the space electric field intensity is enhanced,which results in a higher Ne and electron temperature(Te).Therefore,an appropriate value of space electric field intensity can promote electron avalanches,resulting in uniform and stable plasma by the merging of electron avalanches.However,an excessive value of space electric field intensity leads to the aggregation of space charges and the distortion of the space electric field,which reduce the discharge uniformity.The surface roughness and the surface charge decay are measured to explain the influences of the surface properties and the second electron emission on the discharge uniformity.The results in this work give a comprehensive understanding of the effect of the dielectric materials on the DBD uniformity,and contribute to the selection of dielectric materials for DBD reactor and the realization of atmospheric pressure uniform,stable,and reactive plasma sources.展开更多
Purpose:This study aims to explore how network intermediaries influence collaborative innovation performance within inter-organizational technological collaboration networks.Design/methodology/approach:This study empl...Purpose:This study aims to explore how network intermediaries influence collaborative innovation performance within inter-organizational technological collaboration networks.Design/methodology/approach:This study employs a mixed-method approach,combining quantitative social network analysis with regression techniques to investigate the role of network intermediaries in collaborative innovation performance.Using a patent dataset of Chinese industrial enterprises,the research constructs the collaboration networks and analyzes their structural positions,particularly focusing on their role as intermediaries,characterized by betweenness centrality.Negative binomial regression analysis is employed to assess how these network characteristics shape innovation outcomes.Findings:The study reveals that firms in intermediary positions enhance collaborative innovation performance,but this effect is nuanced.A key finding is that network clustering negatively moderates the intermediary-innovation relationship.Highly clustered networks,while fostering local collaboration,may limit the innovation potential of intermediaries.On the other hand,relationship strength,measured by collaboration intensity and trust among firms,positively moderates the intermediary-innovation link.Research limitations:This study has several limitations that present opportunities for further research.The reliance on quantitative social network analysis may overlook the complexity of intermediaries’roles,and future studies could benefit from incorporating qualitative methods to better understand cultural and institutional factors.Additionally,cross-country comparisons are needed to assess the consistency of these dynamics in different contexts.Practical implications:The study offers practical insights for firms and policymakers.Organizations should strategically position themselves as network intermediaries to access diverse information and resources,thereby improving innovation performance.Building strong trust helps using network intermediary advantages.For firms in highly clustered networks,it is important to seek external partners to avoid limiting their exposure to new ideas and technologies.This research emphasizes the need to balance network diversity with relationship strength for sustained innovation.Originality/value:This research contributes to the literature by offering new insights into the role of network intermediaries,presenting a comprehensive framework for understanding the interaction between network dynamics and firm innovation.展开更多
Magnesium(Mg) and its alloys have been intensively studied to develop the next generation of bone implants recently, but their clinical application is restricted by rapid degradation and unsatisfied osteogenic effect ...Magnesium(Mg) and its alloys have been intensively studied to develop the next generation of bone implants recently, but their clinical application is restricted by rapid degradation and unsatisfied osteogenic effect in vivo. A bioactive chemical conversion Mg-phenolic networks complex coating(e EGCG) was stepwise incorporated by epigallocatechin-3-gallate(EGCG) and exogenous Mg^(2+)on Mg-2Zn magnesium alloy. Simplex EGCG induced chemical conversion coating(c EGCG) was set as compare group. The in vitro corrosion behavior of Mg-2Zn alloy, c EGCG and e EGCG was evaluated in SBF using electrochemical(PDP, EIS) and immersion test. The cytocompatibility was investigated with rat bone marrow mesenchymal stem cells(r BMSCs). Furthermore, the in vivo tests using a rabbit model involved micro computed tomography(Micro-CT) analysis, histological observation, and interface analysis. The results showed that the e EGCG is Mgphenolic multilayer coating incorporated Mg-phenolic networks, which is rougher, more compact and much thicker than c EGCG. The e EGCG highly improved the corrosion resistance of Mg-2Zn alloy, combined with its lower average hemolytic ratios, continuous high scavenging effect ability and relatively moderate contact angle features, resulting in a stable and suitable biological environment, obviously promoted r BMSCs adhesion and proliferation. More importantly, Micro-CT, histological and interface elements distribution evaluations all revealed that the e EGCG effectively inhibited degradation and enhanced bone tissue formation of Mg alloy implants. This study puts forward a promising bioactive chemical conversion coating with Mg-phenolic networks for the application of biodegradable orthopedic implants.展开更多
In order to study the influence of thermal deformation of long-span cable- stayed bridge (LSCSB) on the dynamic characteristics of metro vehicle on the bridge, based on the theory of vehicle-track coupled dynamic...In order to study the influence of thermal deformation of long-span cable- stayed bridge (LSCSB) on the dynamic characteristics of metro vehicle on the bridge, based on the theory of vehicle-track coupled dynamics, the rigid-flexible coupled dynamic model of metro vehicle-track-LSCSB system is established by using finite element method and multi-rigid-body dynamics. Adopting this model, the deformation of LSCSB subject to temperature is analyzed, then the comprehensive effect of track random irregularity and rail deformation caused by temperature load is considered to study the dynamic characteristics of metro vehicle running through the bridge, and finally the influences of temperature increment and running speed on concerned dynamic indices of vehicle are studied. The results show that the LSCSB deforms obviously subject to temperature load, and the overall performance is that the cooling is arched, and the heating is bent, and the shape variable changes almost linearly with the temperature load. According to the parameters studied in this paper, the rail deformation caused by temperature load increases the wheel-rail vertical force, derailment coefficient and wheel load reduction rate by 1.5%, 3.1% and 5% respectively. The vertical acceleration of the vehicle body decreases by 2.4% under the cooling condition, while increases by 3.7% under the heating condition. The dynamic response of the bridge changes under temperature load. The maximum vertical and horizontal displacement in the middle of the main beam span are 6.24 mm and 2.19 mm respectively, and the maximum vertical and horizontal acceleration are 1.29 cm/s<sup>2</sup> and 2.54cm/s<sup>2</sup> respectively. The derailment coefficient and vertical acceleration of vehicle body are more affected by temperature load, and the wheel load reduction rate and wheel-rail vertical force are more affected by speed. The conclusion of this paper provides a reference for subsequent scholars to study the influence of thermal deformation on the dynamic response of vehicles on LSCSB.展开更多
Learning programming has become an important part of education.However,most students have extreme difficulty learning programming and complex algorithms.This is because programming has a hierarchical logic.Solving com...Learning programming has become an important part of education.However,most students have extreme difficulty learning programming and complex algorithms.This is because programming has a hierarchical logic.Solving complex problems requires students to develop skills in decomposing problems.To this end,this paper describes an effective method to develop an online platform for teaching complex algorithms.展开更多
Superlattice hydrogen storage alloys offer a compelling advantage with rapid hydriding rate and high storage capacity.However,its practical applications face challenges including complex structure,low dehydriding capa...Superlattice hydrogen storage alloys offer a compelling advantage with rapid hydriding rate and high storage capacity.However,its practical applications face challenges including complex structure,low dehydriding capacity,and cyclic instability.In this work,we successfully prepared La_(0.66)Mg_(0.34)Ni_(3.5-x)Co_(x) superlattice hydrogen storage alloys with enhanced dehydriding capacity and stability by partially substituting Co for Ni.X-ray diffraction(XRD)refinements analysis reveals the presence of(La,Mg)_(3)Ni_(9),(La,Mg)_5Ni_(19),and LaNi_(5) phases within the alloy.Following Co substitution in the La_(0.06)Mg_(0.34)Ni_(3.4)Co_(0.1)alloy,there is a significant increase in content of the(La,Mg)_(3)Ni_(9) phase and a reduction in the hysteresis factor,resulting in an improved reversible hydrogen storage capacity from 1.45 wt%to 1.60 wt%.The dehydriding kinetics of the alloy is controlled by diffusion model with an activation energy of 8.40 kJ/mol.Furthermore,the dehydriding enthalpy value of the Co-substituted alloy decreases from 30.84 to 29.85 kJ/mol.Impressively,the cycling performance of the alloy after Co substitution exhibits excellent stability,with a capacity retention rate of 92.3%after 100 cycles.These findings provide valuable insights for the development of cost-effective hydrogen storage materials.展开更多
The growth in biomedical data resources has raised potential privacy concerns and risks of genetic information leakage. For instance, exome sequencing aids clinical decisions by comparing data through web services, bu...The growth in biomedical data resources has raised potential privacy concerns and risks of genetic information leakage. For instance, exome sequencing aids clinical decisions by comparing data through web services, but it requires significant trust between users and providers. To alleviate privacy concerns, the most commonly used strategy is to anonymize sensitive data. Unfortunately, studies have shown that anonymization is insufficient to protect against reidentification attacks. Recently, privacy-preserving technologies have been applied to preserve application utility while protecting the privacy of biomedical data. We present the PICOTEES framework, a privacy-preserving online service of phenotype exploration for genetic-diagnostic variants (https://birthdefectlab.cn:3000/). PICOTEES enables privacy-preserving queries of the phenotype spectrum for a single variant by utilizing trusted execution environment technology, which can protect the privacy of the user's query information, backend models, and data, as well as the final results. We demonstrate the utility and performance of PICOTEES by exploring a bioinformatics dataset. The dataset is from a cohort containing 20,909 genetic testing patients with 3,152,508 variants from the Children's Hospital of Fudan University in China, dominated by the Chinese Han population (>99.9%). Our query results yield a large number of unreported diagnostic variants and previously reported pathogenicity.展开更多
recanalization.Yet,due to ischemia-reperfusion injury,over half of these patients still experience poor prognoses.Thus,neuroprotective treatment is imperative to alleviate the ischemic brain injury,and a proof-of-conc...recanalization.Yet,due to ischemia-reperfusion injury,over half of these patients still experience poor prognoses.Thus,neuroprotective treatment is imperative to alleviate the ischemic brain injury,and a proof-of-concept study was conducted on“biodegradable neuroprotective stent”.This concept is premised on the hypothesis that locally released Mg^(2+)/H_(2) from Mg metal within the bloodstream could offer synergistic neuroprotection against reperfusion injury in distant cerebral ischemic tissues.Initially,the study evaluated pure Mg’s neuroactive potential using oxygen-glucose deprivation/reoxygenation(OGD/R)injured neuron cells.Subsequently,a pure Mg wire was implanted into the common carotid artery of the transient middle cerebral artery occlusion(MCAO)rat model to simulate human brain ischemia/reperfusion injury.In vitro analyses revealed that pure Mg extract aided mouse hippocampal neuronal cell(HT-22)in defending against OGD/R injury.Additionally,the protective effects of the Mg wire on behavioral abnormalities,neural injury,blood-brain barrier disruption,and cerebral blood flow reduction in MCAO rats were verified.Conclusively,Mg-based biodegradable neuroprotective implants could serve as an effective local Mg^(2+)/H_(2) delivery system for treating distant cerebral ischemic diseases.展开更多
Accurate and reasonable prediction of industrial electricity consumption is of great significance for promoting regional green transformation and optimizing the energy structure.However,the regional power system is co...Accurate and reasonable prediction of industrial electricity consumption is of great significance for promoting regional green transformation and optimizing the energy structure.However,the regional power system is complicated and uncertain,affected by multiple factors including climate,population and economy.This paper incorporates structure expansion,parameter optimization and rolling mechanism into a system forecasting framework,and designs a novel rolling and fractional-ordered grey system model to forecast the industrial electricity consumption,improving the accuracy of the traditional grey models.The optimal fractional order is obtained by using the particle swarm optimization algorithm,which enhances the model adaptability.Then,the proposed model is employed to forecast and analyze the changing trend of industrial electricity consumption in Fujian province.Experimental results show that industrial electricity consumption in Fujian will maintain an upward growth and it is expected to 186.312 billion kWh in 2026.Compared with other seven benchmark prediction models,the proposed grey system model performs best in terms of both simulation and prediction performance metrics,providing scientific reference for regional energy planning and electricity market operation.展开更多
Infected bone defect is a formidable clinical challenge.Conventional approaches to prevention and treatment for infected bone defects are unsatisfactory.The key elements of the treatment are bone defect reconstruction...Infected bone defect is a formidable clinical challenge.Conventional approaches to prevention and treatment for infected bone defects are unsatisfactory.The key elements of the treatment are bone defect reconstruction,antiinfection,and osteogenesis.Conventional treatment methods remain unsatisfactory owing to the absence of composite integrating materials with anti-infective,and osteogenic activities as well as proper mechanical strength at the same time.In this study,we fabricated a vancomycin-encapsulated hydrogel with bacteriaresponsive release properties combined with a shaved porous(submicron-micron)three-dimensional-printed Ti6Al4V implant.The implant surface,modified with submicron-sized pores through microarc oxidation(MAO),showed enhanced osteogenic activity and integrated well with the hydrogel drug release system,enabling sustained vancomycin release.In vitro experiments underscored the commendable antibacterial ability,biosafety,and osteoinductive potential.Effective antibacterial and osteogenic abilities of the implant were further demonstrated in vivo in infected rabbit bone defects.These results showed that the vancomycinencapsulated hydrogel-loaded microarc-oxidized 3D-printed porous Ti6Al4V can repair the infected bone defects with satisfactory anti-infection and osseointegration effects.展开更多
Endowing implant surfaces with combined antibacterial and osteogenic properties by drug-loaded coatings has made great strides,but how to achieve the combined excellence of infection-triggered bactericidal and in vivo...Endowing implant surfaces with combined antibacterial and osteogenic properties by drug-loaded coatings has made great strides,but how to achieve the combined excellence of infection-triggered bactericidal and in vivo-proven osteogenic activities without causing bacterial resistance still remains a formidable challenge.Herein,antimicrobial peptides(AMPs)with osteogenic fragments were designed and complexed on the surface of silver nanoparticle(AgNP)through hydrogen bonding,and the collagen structure-bionic silk fibroin(SF)was applied to carry AgNPs@AMPs to achieve infection-triggered antibacterial and osteointegration.As verified by TEM,AMPs contributed to the dispersion and size-regulation of AgNPs,with a particle size of about 20 nm,and a clear protein corona structure was observed on the particle surface.The release curve of silver ion displayed that the SF-based coating owned sensitive pH-responsive properties.In the antibacterial test against S.aureus for up to 21 days,the antibacterial rate had always remained above 99%.Meanwhile,the underlying mechanism was revealed,originating from the destruction of the bacterial cell membranes and ROS generation.The SF-based coating was conducive to the adhesion,diffusion,and proliferation of bone marrow stem cells(BMSCs)on the surface,and promoted the expression of osteogenic genes and collagen secretion.The in vivo implantation results showed that compared with the untreated Ti implants,SF-based coating enhanced osseointegration at week 4 and 8.Overall,the AgNPs@AMPs-loaded SF-based coating presented the ability to synergistically inhibit bacteria and promote osseointegration,possessing tremendous potential application prospects in bone defects and related-infection treatments.展开更多
Polyetheretherketone(PEEK)has been an alternative material for titanium in bone defect repair,but its clinical application is limited by its poor osseointegration.In this study,a porous structural design and activated...Polyetheretherketone(PEEK)has been an alternative material for titanium in bone defect repair,but its clinical application is limited by its poor osseointegration.In this study,a porous structural design and activated surface modification were used to enhance the osseointegration capacity of PEEK materials.Porous PEEK scaffolds were manufactured via fused deposition modeling and a polydopamine(PDA)coating chelated with magnesium ions(Mg^(2+))was utilized on the surface.After surface modification,the hydrophilicity of PEEK scaffolds was significantly enhanced,and bioactive Mg^(2+)could be released.In vitro results showed that the activated surface could promote cell proliferation and adhesion and contribute to osteoblast differentiation and mineralization;the released Mg^(2+)promoted angiogenesis and might contribute to the formation of osteogenic H-type vessels.Furthermore,porous PEEK scaffolds were implanted in rabbit femoral condyles for in vivo evaluation of osseointegration.The results showed that the customized three-dimensional porous structure facilitated vascular ingrowth and bone ingrowth within the PEEK scaffolds.The PDA coating enhanced the interfacial osseointegration of porous PEEK scaffolds and the released Mg^(2+)accelerated early bone ingrowth by promoting early angiogenesis during the coating degradation process.This study provides an efficient solution for enhancing the osseointegration of PEEK materials,which has high potential for translational clinical applications.展开更多
Background:Significant brain volume deviation is an essential phenotype in children with neurodevelopmental delay(NDD),but its genetic basis has not been fully characterized.This study attempted to analyze the genetic...Background:Significant brain volume deviation is an essential phenotype in children with neurodevelopmental delay(NDD),but its genetic basis has not been fully characterized.This study attempted to analyze the genetic factors associated with significant whole-brain deviation volume(WBDV).Methods:We established a reference curve based on 4222 subjects ranging in age from the first postnatal day to 18 years.We recruited only NDD patients without acquired etiologies or positive genetic results.Cranial magnetic resonance imaging(MRI)and clinical exome sequencing(2742 genes)data were acquired.A genetic burden test was performed,and the results were compared between patients with and without significant WBDV.Literature review analyses and BrainSpan analysis based on the human brain developmental transcriptome were performed to detect the potential role of genetic risk factors in human brain development.Results:We recruited a total of 253 NDD patients.Among them,26 had significantly decreased WBDV(<-2 standard deviations[SDs]),and 14 had significantly increased WBDV(>+2 SDs).NDD patients with significant WBDV had higher rates of motor development delay(49.8%[106/213]vs.75.0%[30/40],P=0.003)than patients without significant WBDV.Genetic burden analyses found 30 genes with an increased allele frequency of rare variants in patients with significant WBDV.Analyses of the literature further demonstrated that these genes were not randomly identified:burden genes were more related to the brain development than background genes(P=1.656e^(-9)).In seven human brain regions related to motor development,we observed burden genes had higher expression before 37-week gestational age than postnatal stages.Functional analyses found that burden genes were enriched in embryonic brain development,with positive regulation of synaptic growth at the neuromuscular junction,positive regulation of deoxyribonucleic acid templated transcription,and response to hormone,and these genes were shown to be expressed in neural progenitors.Based on single cell sequencing analyses,we found TUBB2B gene had elevated expression levels in neural progenitor cells,interneuron,and excitatory neuron and SOX15 had high expression in interneuron and excitatory neuron.Conclusion:Idiopathic NDD patients with significant brain volume changes detected by MRI had an increased prevalence of motor development delay,which could be explained by the genetic differences characterized herein.展开更多
To the Editor:Approximately 15 million preterm babies,i.e.,those delivered at<37 weeks of gestational age(GA),are born globally every year,and of them,0.4%are extremely premature infants(EPIs),i.e.,those delivered ...To the Editor:Approximately 15 million preterm babies,i.e.,those delivered at<37 weeks of gestational age(GA),are born globally every year,and of them,0.4%are extremely premature infants(EPIs),i.e.,those delivered at<28 weeks of GA.^([1])Iterations of neonatal care have significantly extended the viability of preterm babies.However,improved viability is accompanied by an increased risk of unreversed injuries,such as bronchopulmonary dysplasia and intraventricular hemorrhage.Therefore,a more physiological simulating in utero status is needed to protect EPIs’immature organs during the transitional period and ensure that they develop in the same manner that they would have in the womb.展开更多
The comparative study of submerged arc welding(SAW)and laser hybrid welding(LHW)was carried out for a 690 MPa high strength steel with thickness of 20 mm.Microstructure and ductile–brittle transition temperature(DBTT...The comparative study of submerged arc welding(SAW)and laser hybrid welding(LHW)was carried out for a 690 MPa high strength steel with thickness of 20 mm.Microstructure and ductile–brittle transition temperature(DBTT)evolution in welded zone were elucidated from the aspect of crystallographic structure,particularly,digitization and visualization of 24 variants.The impact toughness of each micro zone in LHW joint is better than that of SAW,in which the DBTT of equivalent fusion line and heat-affected zone(HAZ)can reach−70 and−80℃,while that of SAW is only−50℃.LHW technology induces narrowing of the HAZ and refining of the microstructure obtained in weld metal and HAZ.Meanwhile,the austenite grain size and transformation driving force in the coarse grained heat-affected zone(CGHAZ)are reduced and increased,respectively.It makes variant selection mechanism occurring in CGHAZ of LHW dominate by close-packed plane grouping,which promotes lath bainite formation with high density of high angle grain boundary,especially block boundary dominated by V1/V2 pair.While for SAW,the lower transformation driving force inferred from the large amount of retained austenite in CGHAZ induces Bain grouping of variants,and thus triggers the brittle crack propagating straightly in granular bainite,resulting in lower impact toughness and higher DBTT.展开更多
Selective endovascular hypothermia has been used to provide cooling-induced cerebral neuroprotection,but current catheters do not support thermally-insulated transfer of cold infusate,which results in an increased exi...Selective endovascular hypothermia has been used to provide cooling-induced cerebral neuroprotection,but current catheters do not support thermally-insulated transfer of cold infusate,which results in an increased exit temperature,causes hemodilution,and limits its cooling efficiency.Herein,air-sprayed fibroin/silica-based coatings combined with chemical vapor deposited parylene-C capping film was prepared on catheter.This coating features in dual-sized-hollow-microparticle incorporated structures with low thermal conductivity.The infusate exit temperature is tunable by adjusting the coating thickness and infusion rate.No peeling or cracking was observed on the coatings under bending and rotational scenarios in the vascular models.Its efficiency was verified in a swine model,and the outlet temperature of coated catheter(75μm thickness)was 1.8-2.0◦C lower than that of the uncoated one.This pioneering work on catheter thermal insulation coatings may facilitate the clinical translation of selective endovascular hypothermia for neuroprotection in patients with acute ischemic stroke.展开更多
The Omicron variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)was first confirmed in November 2021 in South Africa^([1])and is more transmissible than other sub-variants.^([2])The influence of Omic...The Omicron variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)was first confirmed in November 2021 in South Africa^([1])and is more transmissible than other sub-variants.^([2])The influence of Omicron in children has been recognized with increased hospital admission rate than Delta wave.^([3,4])But severe clinical outcomes and comorbidity of Omicron are less than Delta in children.^([5])Hospitalized children during the Omicron period were more likely to be younger than that in the pre-Omicron period.^([6])展开更多
基金supported by the following funds:National Natural Science Foundation of China(51935014,52165043)Jiangxi Provincial Cultivation Program for Academic and Technical Leaders of Major Subjects(20225BCJ23008)+1 种基金Jiangxi Provincial Natural Science Foundation(20224ACB204013,20224ACB214008)Scientific Research Project of Anhui Universities(KJ2021A1106)。
文摘Magnesium(Mg)alloys are considered to be a new generation of revolutionary medical metals.Laser-beam powder bed fusion(PBF-LB)is suitable for fabricating metal implants withpersonalized and complicated structures.However,the as-built part usually exhibits undesirable microstructure and unsatisfactory performance.In this work,WE43 parts were firstly fabricated by PBF-LB and then subjected to heat treatment.Although a high densification rate of 99.91%was achieved using suitable processes,the as-built parts exhibited anisotropic and layeredmicrostructure with heterogeneously precipitated Nd-rich intermetallic.After heat treatment,fine and nano-scaled Mg24Y5particles were precipitated.Meanwhile,theα-Mg grainsunderwent recrystallization and turned coarsened slightly,which effectively weakened thetexture intensity and reduced the anisotropy.As a consequence,the yield strength and ultimate tensile strength were significantly improved to(250.2±3.5)MPa and(312±3.7)MPa,respectively,while the elongation was still maintained at a high level of 15.2%.Furthermore,the homogenized microstructure reduced the tendency of localized corrosion and favoredthe development of uniform passivation film.Thus,the degradation rate of WE43 parts was decreased by an order of magnitude.Besides,in-vitro cell experiments proved their favorable biocompatibility.
基金supported by National Key Research and Development Program of China[2023YFB4605800]National Natural Science Foundation of China[51935014,52165043]+3 种基金JiangXi Provincial Natural Science Foundation of China[20224ACB204013,20224ACB214008]Jiangxi Provincial Cultivation Program for Academic and Technical Leaders of Major Subjects[20225BCJ23008]Anhui Provincial Natural Science Foundation[2308085ME171]The University Synergy Innovation Program of Anhui Province[GXXT-2023-025,GXXT-2023-026].
文摘Biomedical magnesium(Mg)alloys have garnered significant attention because of their unique biodegradability,favorable biocompatibility,and suitable mechanical properties.The incorporation of rare earth(RE)elements,with their distinct physical and chemical properties,has greatly contributed to enhancing the mechanical performance,degradation behavior,and biological performance of biomedical Mg alloys.Currently,a series of RE-Mg alloys are being designed and investigated for orthopedic implants and cardiovascular stents,achieving substantial and encouraging research progress.In this work,a comprehensive summary of the state-of-the-art in biomedical RE-Mg alloys is provided.The physiological effects and design standards of RE elements in biomedical Mg alloys are discussed.Particularly,the degradation behavior and mechanical properties,including their underlying action are studied in-depth.Furthermore,the preparation techniques and current application status of RE-Mg alloys are reviewed.Finally,we address the ongoing challenges and propose future prospects to guide the development of high-performance biomedical Mg-RE alloys.
基金supported by National Natural Science Foundation of China(Nos.52037004 and 52177148)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX23_1449).
文摘Dielectric barrier discharge(DBD)is considered as a promising technique to produce large volume uniform plasma at atmospheric pressure,and the dielectric barrier layer between the electrodes plays a key role in the DBD processes and enhancing discharge uniformity.In this work,the uniformity and discharge characteristics of the nanosecond(ns)pulsed DBD with dielectric barrier layers made of alumina,quartz glass,polycarbonate(PC),and polypropylene(PP)are investigated via discharge image observation,voltage-current waveform measurement and optical emission spectral diagnosis.Through analyzing discharge image by gray value standard deviation method,the discharge uniformity is quantitatively calculated.The effects of the space electric field intensity,the electron density(Ne),and the space reactive species on the uniformity are studied with quantifying the gap voltage Ug and the discharge current Ig,analyzing the recorded optical emission spectra,and simulating the temporal distribution of Ne with a one-dimensional fluid model.It is found that as the relative permittivity of the dielectric materials increases,the space electric field intensity is enhanced,which results in a higher Ne and electron temperature(Te).Therefore,an appropriate value of space electric field intensity can promote electron avalanches,resulting in uniform and stable plasma by the merging of electron avalanches.However,an excessive value of space electric field intensity leads to the aggregation of space charges and the distortion of the space electric field,which reduce the discharge uniformity.The surface roughness and the surface charge decay are measured to explain the influences of the surface properties and the second electron emission on the discharge uniformity.The results in this work give a comprehensive understanding of the effect of the dielectric materials on the DBD uniformity,and contribute to the selection of dielectric materials for DBD reactor and the realization of atmospheric pressure uniform,stable,and reactive plasma sources.
基金supported by the National Social Science Fund of China(No.22FGLB035)Fujian Provincial Federation of Social Sciences(No.FJ2023B109).
文摘Purpose:This study aims to explore how network intermediaries influence collaborative innovation performance within inter-organizational technological collaboration networks.Design/methodology/approach:This study employs a mixed-method approach,combining quantitative social network analysis with regression techniques to investigate the role of network intermediaries in collaborative innovation performance.Using a patent dataset of Chinese industrial enterprises,the research constructs the collaboration networks and analyzes their structural positions,particularly focusing on their role as intermediaries,characterized by betweenness centrality.Negative binomial regression analysis is employed to assess how these network characteristics shape innovation outcomes.Findings:The study reveals that firms in intermediary positions enhance collaborative innovation performance,but this effect is nuanced.A key finding is that network clustering negatively moderates the intermediary-innovation relationship.Highly clustered networks,while fostering local collaboration,may limit the innovation potential of intermediaries.On the other hand,relationship strength,measured by collaboration intensity and trust among firms,positively moderates the intermediary-innovation link.Research limitations:This study has several limitations that present opportunities for further research.The reliance on quantitative social network analysis may overlook the complexity of intermediaries’roles,and future studies could benefit from incorporating qualitative methods to better understand cultural and institutional factors.Additionally,cross-country comparisons are needed to assess the consistency of these dynamics in different contexts.Practical implications:The study offers practical insights for firms and policymakers.Organizations should strategically position themselves as network intermediaries to access diverse information and resources,thereby improving innovation performance.Building strong trust helps using network intermediary advantages.For firms in highly clustered networks,it is important to seek external partners to avoid limiting their exposure to new ideas and technologies.This research emphasizes the need to balance network diversity with relationship strength for sustained innovation.Originality/value:This research contributes to the literature by offering new insights into the role of network intermediaries,presenting a comprehensive framework for understanding the interaction between network dynamics and firm innovation.
基金supported by the Key Research and Development Program of Shaanxi Province (2019ZDLSF03-06) and (2020ZDLGY13-05)the National Key Research and Development Program of China (2020YFC1107202)。
文摘Magnesium(Mg) and its alloys have been intensively studied to develop the next generation of bone implants recently, but their clinical application is restricted by rapid degradation and unsatisfied osteogenic effect in vivo. A bioactive chemical conversion Mg-phenolic networks complex coating(e EGCG) was stepwise incorporated by epigallocatechin-3-gallate(EGCG) and exogenous Mg^(2+)on Mg-2Zn magnesium alloy. Simplex EGCG induced chemical conversion coating(c EGCG) was set as compare group. The in vitro corrosion behavior of Mg-2Zn alloy, c EGCG and e EGCG was evaluated in SBF using electrochemical(PDP, EIS) and immersion test. The cytocompatibility was investigated with rat bone marrow mesenchymal stem cells(r BMSCs). Furthermore, the in vivo tests using a rabbit model involved micro computed tomography(Micro-CT) analysis, histological observation, and interface analysis. The results showed that the e EGCG is Mgphenolic multilayer coating incorporated Mg-phenolic networks, which is rougher, more compact and much thicker than c EGCG. The e EGCG highly improved the corrosion resistance of Mg-2Zn alloy, combined with its lower average hemolytic ratios, continuous high scavenging effect ability and relatively moderate contact angle features, resulting in a stable and suitable biological environment, obviously promoted r BMSCs adhesion and proliferation. More importantly, Micro-CT, histological and interface elements distribution evaluations all revealed that the e EGCG effectively inhibited degradation and enhanced bone tissue formation of Mg alloy implants. This study puts forward a promising bioactive chemical conversion coating with Mg-phenolic networks for the application of biodegradable orthopedic implants.
文摘In order to study the influence of thermal deformation of long-span cable- stayed bridge (LSCSB) on the dynamic characteristics of metro vehicle on the bridge, based on the theory of vehicle-track coupled dynamics, the rigid-flexible coupled dynamic model of metro vehicle-track-LSCSB system is established by using finite element method and multi-rigid-body dynamics. Adopting this model, the deformation of LSCSB subject to temperature is analyzed, then the comprehensive effect of track random irregularity and rail deformation caused by temperature load is considered to study the dynamic characteristics of metro vehicle running through the bridge, and finally the influences of temperature increment and running speed on concerned dynamic indices of vehicle are studied. The results show that the LSCSB deforms obviously subject to temperature load, and the overall performance is that the cooling is arched, and the heating is bent, and the shape variable changes almost linearly with the temperature load. According to the parameters studied in this paper, the rail deformation caused by temperature load increases the wheel-rail vertical force, derailment coefficient and wheel load reduction rate by 1.5%, 3.1% and 5% respectively. The vertical acceleration of the vehicle body decreases by 2.4% under the cooling condition, while increases by 3.7% under the heating condition. The dynamic response of the bridge changes under temperature load. The maximum vertical and horizontal displacement in the middle of the main beam span are 6.24 mm and 2.19 mm respectively, and the maximum vertical and horizontal acceleration are 1.29 cm/s<sup>2</sup> and 2.54cm/s<sup>2</sup> respectively. The derailment coefficient and vertical acceleration of vehicle body are more affected by temperature load, and the wheel load reduction rate and wheel-rail vertical force are more affected by speed. The conclusion of this paper provides a reference for subsequent scholars to study the influence of thermal deformation on the dynamic response of vehicles on LSCSB.
基金by the XJTLU Research Fund(Grant No.RDF-21-01-053,TDF21/22-R23-160)External Research Fund(Grant No.RDS10120220093,RDS10120220021).
文摘Learning programming has become an important part of education.However,most students have extreme difficulty learning programming and complex algorithms.This is because programming has a hierarchical logic.Solving complex problems requires students to develop skills in decomposing problems.To this end,this paper describes an effective method to develop an online platform for teaching complex algorithms.
基金Project supported by the National Key R&D Program of China(2022YFB3504700)。
文摘Superlattice hydrogen storage alloys offer a compelling advantage with rapid hydriding rate and high storage capacity.However,its practical applications face challenges including complex structure,low dehydriding capacity,and cyclic instability.In this work,we successfully prepared La_(0.66)Mg_(0.34)Ni_(3.5-x)Co_(x) superlattice hydrogen storage alloys with enhanced dehydriding capacity and stability by partially substituting Co for Ni.X-ray diffraction(XRD)refinements analysis reveals the presence of(La,Mg)_(3)Ni_(9),(La,Mg)_5Ni_(19),and LaNi_(5) phases within the alloy.Following Co substitution in the La_(0.06)Mg_(0.34)Ni_(3.4)Co_(0.1)alloy,there is a significant increase in content of the(La,Mg)_(3)Ni_(9) phase and a reduction in the hysteresis factor,resulting in an improved reversible hydrogen storage capacity from 1.45 wt%to 1.60 wt%.The dehydriding kinetics of the alloy is controlled by diffusion model with an activation energy of 8.40 kJ/mol.Furthermore,the dehydriding enthalpy value of the Co-substituted alloy decreases from 30.84 to 29.85 kJ/mol.Impressively,the cycling performance of the alloy after Co substitution exhibits excellent stability,with a capacity retention rate of 92.3%after 100 cycles.These findings provide valuable insights for the development of cost-effective hydrogen storage materials.
基金funded by the Shanghai Hospital Development Center(SHDC2020CR6028-002 to W.Zhou)National Key R&D Program of China(2020YFC2006402 to Y.Lu)+7 种基金National Key R&D Program of China(2022ZD0116003 to X.Dong)the Science and Technology Commission of Shanghai(22002400700 to S.Wu)Shanghai Municipal Science and Technology Major Project(20Z11900600 to W.Zhou)National Key Research and Development Program(2018YFC0116903 to W.Zhou)Major Research Projects for Young and Middle-aged People of Fujian Province(2021ZQNZD017 to Y.Lu)supported by Key Lab Information Network Security,Ministry of Public Security(to H.Zheng and S.Wang)“Pioneer”and”Leading Goose”R&D Program of Zhejiang(No.2022C01126 to Q.Sun and S.Wang)National Key R&D Program of China(2021YFC2500802 and 2021YFC2500806 to H.Zheng and S.Wang).
文摘The growth in biomedical data resources has raised potential privacy concerns and risks of genetic information leakage. For instance, exome sequencing aids clinical decisions by comparing data through web services, but it requires significant trust between users and providers. To alleviate privacy concerns, the most commonly used strategy is to anonymize sensitive data. Unfortunately, studies have shown that anonymization is insufficient to protect against reidentification attacks. Recently, privacy-preserving technologies have been applied to preserve application utility while protecting the privacy of biomedical data. We present the PICOTEES framework, a privacy-preserving online service of phenotype exploration for genetic-diagnostic variants (https://birthdefectlab.cn:3000/). PICOTEES enables privacy-preserving queries of the phenotype spectrum for a single variant by utilizing trusted execution environment technology, which can protect the privacy of the user's query information, backend models, and data, as well as the final results. We demonstrate the utility and performance of PICOTEES by exploring a bioinformatics dataset. The dataset is from a cohort containing 20,909 genetic testing patients with 3,152,508 variants from the Children's Hospital of Fudan University in China, dominated by the Chinese Han population (>99.9%). Our query results yield a large number of unreported diagnostic variants and previously reported pathogenicity.
基金funded by National Natural Science Foundation of China(82027802,82102220)Research Funding on Translational Medicine from Beijing Municipal Science and Technology Commission(Z221100007422023)+4 种基金Beijing Hospitals Authority Clinical Medicine Development of Special Funding Support(YGLX202325)Non-profit Central Research Institute Fund of Chinese Academy of Medical(2023-JKCS-09)Beijing Association for Science and Technology Youth Talent Support Program(BYESS2022081)Science and Technology Innovation Service Capacity Building Project of Beijing Municipal Education Commission(11000023T000002157177)Outstanding Young Talents Program of Capital Medical University(B2305),Beijing Municipal Natural Science Foundation(7244510),Beijing Nova Program(20230484286).
文摘recanalization.Yet,due to ischemia-reperfusion injury,over half of these patients still experience poor prognoses.Thus,neuroprotective treatment is imperative to alleviate the ischemic brain injury,and a proof-of-concept study was conducted on“biodegradable neuroprotective stent”.This concept is premised on the hypothesis that locally released Mg^(2+)/H_(2) from Mg metal within the bloodstream could offer synergistic neuroprotection against reperfusion injury in distant cerebral ischemic tissues.Initially,the study evaluated pure Mg’s neuroactive potential using oxygen-glucose deprivation/reoxygenation(OGD/R)injured neuron cells.Subsequently,a pure Mg wire was implanted into the common carotid artery of the transient middle cerebral artery occlusion(MCAO)rat model to simulate human brain ischemia/reperfusion injury.In vitro analyses revealed that pure Mg extract aided mouse hippocampal neuronal cell(HT-22)in defending against OGD/R injury.Additionally,the protective effects of the Mg wire on behavioral abnormalities,neural injury,blood-brain barrier disruption,and cerebral blood flow reduction in MCAO rats were verified.Conclusively,Mg-based biodegradable neuroprotective implants could serve as an effective local Mg^(2+)/H_(2) delivery system for treating distant cerebral ischemic diseases.
基金supported in part by the National Social Science Fund of China under Grant No.22FGLB035Fujian Provincial Federation of Social Sciences under Grant No.FJ2023B109.
文摘Accurate and reasonable prediction of industrial electricity consumption is of great significance for promoting regional green transformation and optimizing the energy structure.However,the regional power system is complicated and uncertain,affected by multiple factors including climate,population and economy.This paper incorporates structure expansion,parameter optimization and rolling mechanism into a system forecasting framework,and designs a novel rolling and fractional-ordered grey system model to forecast the industrial electricity consumption,improving the accuracy of the traditional grey models.The optimal fractional order is obtained by using the particle swarm optimization algorithm,which enhances the model adaptability.Then,the proposed model is employed to forecast and analyze the changing trend of industrial electricity consumption in Fujian province.Experimental results show that industrial electricity consumption in Fujian will maintain an upward growth and it is expected to 186.312 billion kWh in 2026.Compared with other seven benchmark prediction models,the proposed grey system model performs best in terms of both simulation and prediction performance metrics,providing scientific reference for regional energy planning and electricity market operation.
基金supported by the National Natural Science Foundation of China[grant number 82202729]the Natural Science Foundation of Shandong Province[grant number ZR2022QH261]+2 种基金the Taishan Scholar Project of Shandong Province[grant number tsqn202306355]the National Natural Science Foundation of China[grant number 32101087]the Tianjin Municipal Science and Technology Program(21JCZDJC01100).
文摘Infected bone defect is a formidable clinical challenge.Conventional approaches to prevention and treatment for infected bone defects are unsatisfactory.The key elements of the treatment are bone defect reconstruction,antiinfection,and osteogenesis.Conventional treatment methods remain unsatisfactory owing to the absence of composite integrating materials with anti-infective,and osteogenic activities as well as proper mechanical strength at the same time.In this study,we fabricated a vancomycin-encapsulated hydrogel with bacteriaresponsive release properties combined with a shaved porous(submicron-micron)three-dimensional-printed Ti6Al4V implant.The implant surface,modified with submicron-sized pores through microarc oxidation(MAO),showed enhanced osteogenic activity and integrated well with the hydrogel drug release system,enabling sustained vancomycin release.In vitro experiments underscored the commendable antibacterial ability,biosafety,and osteoinductive potential.Effective antibacterial and osteogenic abilities of the implant were further demonstrated in vivo in infected rabbit bone defects.These results showed that the vancomycinencapsulated hydrogel-loaded microarc-oxidized 3D-printed porous Ti6Al4V can repair the infected bone defects with satisfactory anti-infection and osseointegration effects.
基金supported by the National Natural Science Foundation of China(Grant numbers 32071327,32101087)Shaanxi Science and Technology Association(2022JQ-312).
文摘Endowing implant surfaces with combined antibacterial and osteogenic properties by drug-loaded coatings has made great strides,but how to achieve the combined excellence of infection-triggered bactericidal and in vivo-proven osteogenic activities without causing bacterial resistance still remains a formidable challenge.Herein,antimicrobial peptides(AMPs)with osteogenic fragments were designed and complexed on the surface of silver nanoparticle(AgNP)through hydrogen bonding,and the collagen structure-bionic silk fibroin(SF)was applied to carry AgNPs@AMPs to achieve infection-triggered antibacterial and osteointegration.As verified by TEM,AMPs contributed to the dispersion and size-regulation of AgNPs,with a particle size of about 20 nm,and a clear protein corona structure was observed on the particle surface.The release curve of silver ion displayed that the SF-based coating owned sensitive pH-responsive properties.In the antibacterial test against S.aureus for up to 21 days,the antibacterial rate had always remained above 99%.Meanwhile,the underlying mechanism was revealed,originating from the destruction of the bacterial cell membranes and ROS generation.The SF-based coating was conducive to the adhesion,diffusion,and proliferation of bone marrow stem cells(BMSCs)on the surface,and promoted the expression of osteogenic genes and collagen secretion.The in vivo implantation results showed that compared with the untreated Ti implants,SF-based coating enhanced osseointegration at week 4 and 8.Overall,the AgNPs@AMPs-loaded SF-based coating presented the ability to synergistically inhibit bacteria and promote osseointegration,possessing tremendous potential application prospects in bone defects and related-infection treatments.
基金supported by grants from the National Natural Science Foundation of China(No.51871239,No.32101087,No.52171244).
文摘Polyetheretherketone(PEEK)has been an alternative material for titanium in bone defect repair,but its clinical application is limited by its poor osseointegration.In this study,a porous structural design and activated surface modification were used to enhance the osseointegration capacity of PEEK materials.Porous PEEK scaffolds were manufactured via fused deposition modeling and a polydopamine(PDA)coating chelated with magnesium ions(Mg^(2+))was utilized on the surface.After surface modification,the hydrophilicity of PEEK scaffolds was significantly enhanced,and bioactive Mg^(2+)could be released.In vitro results showed that the activated surface could promote cell proliferation and adhesion and contribute to osteoblast differentiation and mineralization;the released Mg^(2+)promoted angiogenesis and might contribute to the formation of osteogenic H-type vessels.Furthermore,porous PEEK scaffolds were implanted in rabbit femoral condyles for in vivo evaluation of osseointegration.The results showed that the customized three-dimensional porous structure facilitated vascular ingrowth and bone ingrowth within the PEEK scaffolds.The PDA coating enhanced the interfacial osseointegration of porous PEEK scaffolds and the released Mg^(2+)accelerated early bone ingrowth by promoting early angiogenesis during the coating degradation process.This study provides an efficient solution for enhancing the osseointegration of PEEK materials,which has high potential for translational clinical applications.
基金grants from the Science and Technology Commission of Shanghai Municipal(No.19411964400)Shanghai Municipal Science and Technology Major Project(No.2018SHZDZX01)ZJLab.
文摘Background:Significant brain volume deviation is an essential phenotype in children with neurodevelopmental delay(NDD),but its genetic basis has not been fully characterized.This study attempted to analyze the genetic factors associated with significant whole-brain deviation volume(WBDV).Methods:We established a reference curve based on 4222 subjects ranging in age from the first postnatal day to 18 years.We recruited only NDD patients without acquired etiologies or positive genetic results.Cranial magnetic resonance imaging(MRI)and clinical exome sequencing(2742 genes)data were acquired.A genetic burden test was performed,and the results were compared between patients with and without significant WBDV.Literature review analyses and BrainSpan analysis based on the human brain developmental transcriptome were performed to detect the potential role of genetic risk factors in human brain development.Results:We recruited a total of 253 NDD patients.Among them,26 had significantly decreased WBDV(<-2 standard deviations[SDs]),and 14 had significantly increased WBDV(>+2 SDs).NDD patients with significant WBDV had higher rates of motor development delay(49.8%[106/213]vs.75.0%[30/40],P=0.003)than patients without significant WBDV.Genetic burden analyses found 30 genes with an increased allele frequency of rare variants in patients with significant WBDV.Analyses of the literature further demonstrated that these genes were not randomly identified:burden genes were more related to the brain development than background genes(P=1.656e^(-9)).In seven human brain regions related to motor development,we observed burden genes had higher expression before 37-week gestational age than postnatal stages.Functional analyses found that burden genes were enriched in embryonic brain development,with positive regulation of synaptic growth at the neuromuscular junction,positive regulation of deoxyribonucleic acid templated transcription,and response to hormone,and these genes were shown to be expressed in neural progenitors.Based on single cell sequencing analyses,we found TUBB2B gene had elevated expression levels in neural progenitor cells,interneuron,and excitatory neuron and SOX15 had high expression in interneuron and excitatory neuron.Conclusion:Idiopathic NDD patients with significant brain volume changes detected by MRI had an increased prevalence of motor development delay,which could be explained by the genetic differences characterized herein.
文摘To the Editor:Approximately 15 million preterm babies,i.e.,those delivered at<37 weeks of gestational age(GA),are born globally every year,and of them,0.4%are extremely premature infants(EPIs),i.e.,those delivered at<28 weeks of GA.^([1])Iterations of neonatal care have significantly extended the viability of preterm babies.However,improved viability is accompanied by an increased risk of unreversed injuries,such as bronchopulmonary dysplasia and intraventricular hemorrhage.Therefore,a more physiological simulating in utero status is needed to protect EPIs’immature organs during the transitional period and ensure that they develop in the same manner that they would have in the womb.
基金financially supported by the National Natural Science Foundation of China(No.52001023)the Special Fund for Science and Technology Project of Guangdong Province(No.SDZX2020008)the Key Research and Development Program of Shandong Province,China(No.2019JZZY020238).
文摘The comparative study of submerged arc welding(SAW)and laser hybrid welding(LHW)was carried out for a 690 MPa high strength steel with thickness of 20 mm.Microstructure and ductile–brittle transition temperature(DBTT)evolution in welded zone were elucidated from the aspect of crystallographic structure,particularly,digitization and visualization of 24 variants.The impact toughness of each micro zone in LHW joint is better than that of SAW,in which the DBTT of equivalent fusion line and heat-affected zone(HAZ)can reach−70 and−80℃,while that of SAW is only−50℃.LHW technology induces narrowing of the HAZ and refining of the microstructure obtained in weld metal and HAZ.Meanwhile,the austenite grain size and transformation driving force in the coarse grained heat-affected zone(CGHAZ)are reduced and increased,respectively.It makes variant selection mechanism occurring in CGHAZ of LHW dominate by close-packed plane grouping,which promotes lath bainite formation with high density of high angle grain boundary,especially block boundary dominated by V1/V2 pair.While for SAW,the lower transformation driving force inferred from the large amount of retained austenite in CGHAZ induces Bain grouping of variants,and thus triggers the brittle crack propagating straightly in granular bainite,resulting in lower impact toughness and higher DBTT.
基金supported by National Natural Science Foundation of China(82102220,82027802,61975017,82071468)Beijing Municipal Science and Technology Commission(Z221100007422023)+1 种基金General Projects of Scientific and Technological Plan of Beijing Municipal Education Commission(KM202010025023)Talents Gathering Project of Xuanwu Hospital Capital Medical University.
文摘Selective endovascular hypothermia has been used to provide cooling-induced cerebral neuroprotection,but current catheters do not support thermally-insulated transfer of cold infusate,which results in an increased exit temperature,causes hemodilution,and limits its cooling efficiency.Herein,air-sprayed fibroin/silica-based coatings combined with chemical vapor deposited parylene-C capping film was prepared on catheter.This coating features in dual-sized-hollow-microparticle incorporated structures with low thermal conductivity.The infusate exit temperature is tunable by adjusting the coating thickness and infusion rate.No peeling or cracking was observed on the coatings under bending and rotational scenarios in the vascular models.Its efficiency was verified in a swine model,and the outlet temperature of coated catheter(75μm thickness)was 1.8-2.0◦C lower than that of the uncoated one.This pioneering work on catheter thermal insulation coatings may facilitate the clinical translation of selective endovascular hypothermia for neuroprotection in patients with acute ischemic stroke.
基金funded by the National Key Research and Development Program of China(Nos.2021YFC2701800 and 2021YFC2701801)the Shanghai Municipal Science and Technology Major Project(No.ZD2021CY001).
文摘The Omicron variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)was first confirmed in November 2021 in South Africa^([1])and is more transmissible than other sub-variants.^([2])The influence of Omicron in children has been recognized with increased hospital admission rate than Delta wave.^([3,4])But severe clinical outcomes and comorbidity of Omicron are less than Delta in children.^([5])Hospitalized children during the Omicron period were more likely to be younger than that in the pre-Omicron period.^([6])
