The therapeutic efficacy of hepatocellular carcinoma(HCC)medication is severely compromised by inadequate drug delivery to tumor sites.Herein,we fabricated a biomimetic nanoplatform for improved drug targeting ability...The therapeutic efficacy of hepatocellular carcinoma(HCC)medication is severely compromised by inadequate drug delivery to tumor sites.Herein,we fabricated a biomimetic nanoplatform for improved drug targeting ability by wrapping H22 tumor cell membranes around natural chalk to encapsulate the model drug doxorubicin(C-DOX@H22 CM).When camouflaged with H22 tumor cell membranes,C-DOX@H22 CM achieved primary targeting to the tumor tissues due to the immune escape ability and secondary deep targeting to HCC cells owing to the homologous targeting properties.The cellular uptake of C-DOX@H22 CM by H22 cells was via clathrin-mediated endocytosis.Meanwhile,C-DOX@H22 CM exhibited the property of deep penetration into dense tumor tissues.Moreover,the pH-responsive characteristics of the natural chalk enabled C-DOX@H22 CM to achieve endosomal escape and drug release,thereby expanding its antitumor effects without compromising biocompatibility.Importantly,the in vivo experiments also confirmed that C-DOX@H22 CM had favorable antitumor efficacy and biosafety in the H22 tumor-bearing mouse model.Overall,the novel C-DOX@H22 CM nanoplatform provides a safe and effective treatment option for HCC and has the potential to achieve clinical translation for the targeted delivery of other drugs for the treatment of various tumors.展开更多
The circulating avian influenza viruses in wild birds have a high possibility of spillover into domestic birds or mammals at the wild bird–domestic bird or bird–mammal interface. H8N4 viruses primarily circulate in ...The circulating avian influenza viruses in wild birds have a high possibility of spillover into domestic birds or mammals at the wild bird–domestic bird or bird–mammal interface. H8N4 viruses primarily circulate in migratory wild waterfowl and have rarely been identified in domestic birds. In this study, we summarized the spatial and temporal distribution of global H8 viruses, specified their natural reservoirs, and performed detailed evolutionary analysis onthe dominant H8N4 viruses. Here, we also report a novel H8N4 virus isolated from a Eurasian coot sample froma wetland in eastern China in 2022. Animal infection studies indicated that the wild bird-originated H8N4 virus can replicate and transmit efficiently in ducks but has not adapted to chickens. Additionally, this naturally isolated H8N4 virus can replicate in mice without prior adaptation. These results indicate that H8 viruses exist mainly in the wild duck reservoir and pose a high infection risk to domestic ducks. Therefore, the active surveillance of influenza viruses at the wild and domestic waterfowl interface will contribute to monitoring the circulation of these viruses.展开更多
Although the complex structure-preserving method presented in our previous studies can be used to investigate the orbit–attitude–vibration coupled dynamic behaviors of the spatial flexible damping beam,the simulatio...Although the complex structure-preserving method presented in our previous studies can be used to investigate the orbit–attitude–vibration coupled dynamic behaviors of the spatial flexible damping beam,the simulation speed still needs to be improved.In this paper,the infinite-dimensional dynamic model describing the orbit–attitude–vibration coupled dynamic problem of the spatial flexible damping beam is pretreated by the method of separation of variables,and the second-level fourth-order symplectic Runge–Kutta scheme is constructed to investigate the coupling dynamic behaviors of the spatial flexible damping beam quickly.Compared with the simulation speed of the complex structure-preserving method,the simulation speed of the symplectic Runge–Kutta method is faster,which benefits from the pretreatment step.The effect of the initial radial velocity on the transverse vibration as well as on the attitude evolution of the spatial flexible damping beam is presented in the numerical examples.From the numerical results about the effect of the initial radial velocity,it can be found that the appearance of the initial radial velocity can decrease the vibration frequency of the spatial beam and shorten the evolution interval for the attitude angle to tend towards a stable value significantly.In addition,the validity of the numerical results reported in this paper is verified by comparing with some numerical results presented in our previous studies.展开更多
Background Ulcerative colitis(UC)is a chronic,relapsing inflammatory bowel disease with complex aetiology and limited treatment options.Antimicrobial peptides(AMPs),as endogenous immune effectors,have recently emerged...Background Ulcerative colitis(UC)is a chronic,relapsing inflammatory bowel disease with complex aetiology and limited treatment options.Antimicrobial peptides(AMPs),as endogenous immune effectors,have recently emerged as promising therapeutic agents in UC.However,systematic identification and functional evaluation of AMPs remain underexplored.We aimed to discover novel AMPs with potential therapeutic efficacy in UC by leveraging machine learning-based prediction and validating their impact in an experimental colitis model.Methods We established a machine learning-driven pipeline to predict candidate AMPs based on their structural and functional features.Top-ranked peptides were synthesised and subjected to in vitro antibacterial assays and proteolytic stability tests.Their therapeutic potential was evaluated using a dextran sulfate sodium(DSS)-induced colitis mouse model,assessing clinical indicators,histopathology,inflammatory markers and gut microbiota alterations.Metagenomic and metabolomic analyses provided insights into microbial community dynamics and metabolic pathways.To probe the role of gut microbes in AMP-mediated gut homeostasis,we conducted Akkermansia(A.)muciniphila replenishment experiments.Results Several AMPs identified by machine learning exhibited potent antimicrobial activity and resistance to proteolytic degradation.In vivo,AMP administration ameliorated DSS-induced colitis symptoms,including body weight loss,Disease Activity Index and histological damage.Treatment also modulated the gut microbiome,increasing the abundance of A.muciniphila and restoring microbial balance.Functional metagenomic profiling revealed enrichment of genes involved in mucosal barrier protection and immunoregulation.These findings were supported by improved inflammatory cytokine profiles and enhanced epithelial integrity.Conclusions Our findings demonstrate that machine learning-guided discovery of AMPs is a viable approach to identify promising therapeutic agents for UC.By integrating multi-omics analyses,we reveal potential microbiota-mediated mechanisms underlying AMP efficacy.These insights provide a strong foundation for advancing AMP-based strategies in UC management.展开更多
Random loadings(RL)are prevalent in mechanical systems,yet their inherent stochasticity poses significant challenges to structural fatigue reliability assessment.In this study,a three-dimensional fatigue reliability m...Random loadings(RL)are prevalent in mechanical systems,yet their inherent stochasticity poses significant challenges to structural fatigue reliability assessment.In this study,a three-dimensional fatigue reliability model is developed under RL through amplitude modulating and Fourier transformation.The non-Gaussian RL characteristics are accurately characterized by employing power spectral density and loading kurtosis.The equivalent initial crack size distributions are evaluated through three-dimensional fatigue growth theory by joint use of the standard fatigue stress-life(S-N)data and the fatigue crack growth data of the materials.Fatigue life distributions in specimens made of different materials with different geometries and thicknesses are analyzed under RL.It is shown that fatigue life exhibits negative correlations with power spectral density,kurtosis,and initial crack size.Especially,it is found that fatigue life and kurtosis approximately follow a power–law relationship,with both mean and variance decreasing as kurtosis increases.Validations against the experimental data available in the literature show that the present model can provide an efficient prediction of the fatigue life of mechanical systems under RL with limited experiment data.展开更多
Intrauterine adhesion(IUA)is a prevalent complication arising from uterine surgery,significantly impacting women’s fertility and overall quality of life.The conventional clinical approach involves hysteroscopic separ...Intrauterine adhesion(IUA)is a prevalent complication arising from uterine surgery,significantly impacting women’s fertility and overall quality of life.The conventional clinical approach involves hysteroscopic separation of uterine adhesions,though this method poses operational challenges and carries risks of postop-erative re-adhesion.Alternatively,the intraoperative placement of intrauterine devices or support balloons can act as a physical barrier to prevent adhesion formation.However,its effectiveness is limited and it may result in secondary damage to the endothe-lial tissue.To tackle these challenges,we have engineered a temperature-responsive hydrogel incorporating Pluronic HP407/HP188 pharmaceutical excipients and recombinant typeⅢcollagen(rColⅢ)as a bioactive element.Upon in situ injection into the uterine cavity,this hydrogel transitions from a sol–gel phase to a gel in response to body temperature changes,thereby minimizing nonspecific distribution and prolonging the duration of treatment.In vitro studies demonstrate that rColⅢtemperature-responsive hydrogels ex-hibit favorable biocompatibility,exhibit a recruitment effect on human endometrial stromal cells,suppress the expression of the fibrotic factor transforming growth factor beta 1 and promote angiogenesis.To evaluate its efficacy in preventing IUA via in vivo experiments,we employed sexually mature female rats for IUA modeling and compared its performance with a commercially available product,cross-linked sodium hyaluronate gel.The results indicate that rColⅢtemperature-responsive hydrogels significantly enhance retention at the injury site,substantially promote endometrial regeneration,augment endometrial blood supply and reduce abnormal fibrin depo-sition.This study suggests that rColⅢtemperature-responsive hydrogels can effectively prevent post-surgical uterine adhesions,highlighting their potential as a promising adhesion prevention strategy.展开更多
The presence of a surface oxide film(B_(2)O_(3))on boron(B)particles significantly compromises their combustion efficiency and kinetic performance in fuel-rich solid propellants.This study proposes an innovative conti...The presence of a surface oxide film(B_(2)O_(3))on boron(B)particles significantly compromises their combustion efficiency and kinetic performance in fuel-rich solid propellants.This study proposes an innovative continuous modification strategy combining non-thermal plasma(NTP)etching with fluorocarbon passivation.Characterization and kinetic analysis revealed that reactive plasma species—including atomic hydrogen(H),electronically excited molecular hydrogen(H_(2)^(*)),vibrationally excited molecular hydrogen(H_(2)v),and hydrogen ions(H^(+))—dominate the reduction of B_(2)O_(3)through lowering the transition energy barrier and shifting the reaction spontaneity.Subsequent argon plasma fragmentation of C_(8)F_(18)generates fluorocarbon radicals that form conformal passivation coatings(thickness:7 nm)on purified boron surfaces.The modified boron particles exhibit 37.5℃lower exothermic peak temperature and 27.2%higher heat release(14.8 kJ/g vs.11.6 kJ/g)compared to untreated counterparts.Combustion diagnostics reveal 194%increase in maximum flame height(135.10 mm vs.46.03 mm)and 134%enhancement in flame propagation rate(4.44 cm/s vs.1.90 cm/s).This NTP-based surface engineering approach establishes a scalable pathway for developing highperformance boron-based energetic composites.展开更多
The H5N8 avian influenza viruses have been widely circulating in wild birds and are responsible for the loss of over 33 million domestic poultry in Europe, Russia, Middle East, and Asia since January 2020. To monitor ...The H5N8 avian influenza viruses have been widely circulating in wild birds and are responsible for the loss of over 33 million domestic poultry in Europe, Russia, Middle East, and Asia since January 2020. To monitor the invasion and spread of the H5N8 virus in China, we performed active surveillance by analyzing 317 wild bird samples and swab samples collected from 41,172 poultry all over the country. We isolated 22 H5N8 viruses from wild birds and 14 H5N8 viruses from waterfowls. Genetic analysis indicated that the 36 viruses formed two different genotypes: one genotype viruses were widely detected from different wild birds and domestic waterfowls;the other genotype was isolated from a whopper swan. We further revealed the origin and spatiotemporal spread of these two distinct H5N8 virus genotypes in 2020 and 2021. Animal studies indicated that the H5N8 isolates are highly pathogenic to chickens, mildly pathogenic in ducks, but have distinct pathotypes in mice. Moreover, we found that vaccinated poultry in China could be completely protected against H5N8 virus challenge. Given that the H5N8 viruses are likely to continue to spread in wild birds, vaccination of poultry is highly recommended in high-risk countries to prevent H5N8 avian influenza.展开更多
Dear Editor, Live poultry markets are the major trading system of poultry in China and many other countries, and are also thought to be important for the generation and spread of avian influenza viruses and other avia...Dear Editor, Live poultry markets are the major trading system of poultry in China and many other countries, and are also thought to be important for the generation and spread of avian influenza viruses and other avian pathogens (Zhang et al., 2013;Shi et al., 2017;Quan et al., 2018).展开更多
Biodegradable polyamines have long been studied as potential recombinant viral gene vectors.Spermine(SPE) is an endogenous tetra-amine with excellent biocompatibility yet poor gene condensation capacity. We have previ...Biodegradable polyamines have long been studied as potential recombinant viral gene vectors.Spermine(SPE) is an endogenous tetra-amine with excellent biocompatibility yet poor gene condensation capacity. We have previously synthesized a polyspermine based on SPE and poly(ethylene glycol)(PEG)diacrylate(SPE-alt-PEG) for enhanced transfection performance, but the synthesized SPE-alt-PEG still lacked specificity towards cancer cells. In this study, folic acid(FA) was incorporated into SPE-alt-PEG to fabricate a targeted gene delivery vector(FA-SPE-PEG) via an acylation reaction. FA-SPE-PEG exhibited mild cytotoxicity in both cancer cells and normal cells. FA-SPE-PEG possessed higher transfection efficiency than PEI 25 K and Lipofectamines2000 in two tested cancer cell lines at functional weight ratios, and its superiority over untargeted SPE-alt-PEG was prominent in cells with overexpressed folate receptors(FRs). Moreover, in vivo delivery of green fluorescent protein(GFP) with FA-SPE-PEG resulted in highest fluorescent signal intensity of all investigated groups. FA-SPE-PEG showed remarkably enhanced specificity towards cancer cells both in vivo and in vitro due to the interaction between FA and FRs. Taken together, FA-SPE-PEG was demonstrated to be a prospective targeted gene delivery vector with high transfection capacity and excellent biocompatibility.展开更多
The increasing power density of IT electronics and the enormous energy consumption of data centers lead to the urgent demand for efficient cooling technology.Due to its efficiency and safety,liquid-cooled heat sink te...The increasing power density of IT electronics and the enormous energy consumption of data centers lead to the urgent demand for efficient cooling technology.Due to its efficiency and safety,liquid-cooled heat sink technology may gradually replace air-cooled technology over time.With the ambient or higher water supply temperature,the liquid-cooled technology shortens the operating time of the chiller and improves its coefficient of performance,while the pump power consumption may increase for satisfying the constant cooling capacity.Therefore,it is significant to study the optimal water supply temperature to achieve energy-efficient operation of data centers.A virtual 30.1 kW data center is considered as the case,the liquid-cooled system is constructed with a combination of innovative manifold microchannel heat sink with oblique fins and indirect evaporative cooling technology to minimize energy consumption.A hybrid thermal management model integrating the heat dissipation model and the power consumption model is established by TRNSYS and FLUENT software.To the highest chip-safe operating temperature premise,the energy performance is analyzed under various water supply temperatures in Guangzhou.The result shows that only 21.5-hour mechanical cooling is needed with the 30℃server inlet temperature throughout the year.And the minimized power consumption occurs with the constant 29℃server inlet temperature.Moreover,the temperature adaptive control strategy(TACS)is adopted to test the cooling system power consumption under different regulation frequencies,and the by-week TACS can achieve another 11.5%energy saving than the minimum power consumption of the constant temperature control strategy.展开更多
Supported Pd catalysts show superior activities for olefin productions from alkynes through semi-hydrogenation reactions,but over-hydrogenation into alkanes highly decreases olefin selectivity.Using phenylacetylene se...Supported Pd catalysts show superior activities for olefin productions from alkynes through semi-hydrogenation reactions,but over-hydrogenation into alkanes highly decreases olefin selectivity.Using phenylacetylene semi-hydrogenation as a model reaction,here we explore the optimization approaches toward better Pd catalysts for alkyne semi-hydrogenation through investigating support effect and metal-support interactions.The results show that the states of Pd with supports can be tuned by varying oxide reducibility,loading ratios,and post-treatments.In our system,0.06 wt.%Pd on rutile-TiO_(2) nanorods shows the highest activity owing to the synergistic effects of single-atoms and clusters.Support reducibility can change the filling degrees of Pd 4d orbitals through varying interfacial bonding strengths,which further affect catalytic activity and selectivity.展开更多
The incidence of intrauterine adhesions(IUA)has increased with the rising utilization of intrauterine surgery.The postoperative physical barrier methods commonly used,such as balloons and other fillers,have limited ef...The incidence of intrauterine adhesions(IUA)has increased with the rising utilization of intrauterine surgery.The postoperative physical barrier methods commonly used,such as balloons and other fillers,have limited effectiveness and may even cause further damage to the remaining endometrial tissue.Herein,we developed an injectable thermosensitive hydrogel using Pluronic F127/F68 as pharmaceutical excipients and curcumin as a natural active molecule.The hydrogel effectively addresses solubility and low bioavailability issues associated with curcumin.In vitro,drug release assays revealed that the amorphous curcumin hydrogel promotes dissolution and sustained release of curcumin.In vitro experiments reveal high biocompatibility of the hydrogel and its ability to enhance vascular formation while inhibiting the expression of fibrotic factor TGF-β1.To assess the effectiveness of preventing IUAs,in vivo experiments were conducted using IUA rats and compared with a class III medical device,a new-crosslinked hyaluronic acid(NCHA)gel.According to the study,curcumin hydrogel is more effective than the NCHA group in improving the regeneration of the endometrium,increasing the blood supply to the endometrium and reducing the abnormal deposition of fibrin,thus preventing IUA more effectively.This study provides a promising strategy for treating and preventing IUA.展开更多
In creeping solids,plane stress and plane strain solutions for asymptotic singular crack-tip fields have been first put forward by Riedel and Rice with C^(*)as the dominating parameter and developed by Xiang and Guo i...In creeping solids,plane stress and plane strain solutions for asymptotic singular crack-tip fields have been first put forward by Riedel and Rice with C^(*)as the dominating parameter and developed by Xiang and Guo into three-dimensional solution(3D)for stationary cracks under the domination of C^(*)with the constraint factor Tz.However,how to characterize the 3D crack-tip fields under creep damage-induced quasistatic growing conditions remains challenging.In this study,we reveal that,for 3D quasistatic growing cracks,the leading singular solution can effectively characterize the crack-tip stress distributions with relative errors less than 10.8%for relative creep time up to 0.8 in various specimens with finite thickness.For a given relative time,Tz distributions can be unified by the equivalent thickness concept,Beq.The results show that C^(*)-T_(z) can effectively quantify both the load and constraint effects on the crack-tip fields.Such geometry independent dominance can considerably simplify the treatments of load and constraint effects,thereby promoting the application of fracture mechanics in high-temperature damage tolerance designs.展开更多
基金supported by Zhejiang Medical Science and Technology Project(No.2023KY704)Zhejiang Traditional Chinese Medicine Science and Technology Project(Nos.2023ZR107 and 2024ZF094)+1 种基金Special Research Fund for Hospital Pharmacy of Zhejiang Pharmaceutical Association(No.2021ZYY08)Zhejiang Medical Association Clinical Research Fund(Nos.2021ZYC-A64 and 2021ZYC-A67).
文摘The therapeutic efficacy of hepatocellular carcinoma(HCC)medication is severely compromised by inadequate drug delivery to tumor sites.Herein,we fabricated a biomimetic nanoplatform for improved drug targeting ability by wrapping H22 tumor cell membranes around natural chalk to encapsulate the model drug doxorubicin(C-DOX@H22 CM).When camouflaged with H22 tumor cell membranes,C-DOX@H22 CM achieved primary targeting to the tumor tissues due to the immune escape ability and secondary deep targeting to HCC cells owing to the homologous targeting properties.The cellular uptake of C-DOX@H22 CM by H22 cells was via clathrin-mediated endocytosis.Meanwhile,C-DOX@H22 CM exhibited the property of deep penetration into dense tumor tissues.Moreover,the pH-responsive characteristics of the natural chalk enabled C-DOX@H22 CM to achieve endosomal escape and drug release,thereby expanding its antitumor effects without compromising biocompatibility.Importantly,the in vivo experiments also confirmed that C-DOX@H22 CM had favorable antitumor efficacy and biosafety in the H22 tumor-bearing mouse model.Overall,the novel C-DOX@H22 CM nanoplatform provides a safe and effective treatment option for HCC and has the potential to achieve clinical translation for the targeted delivery of other drugs for the treatment of various tumors.
基金supported by the National Key Research and Development Program of China (2021YFD1800200)the Natural Science Foundation of Shandong Province, China (ZR2021MC087)the State Key Laboratory of Veterinary Biotechnology, China (SKLVBF202201)。
文摘The circulating avian influenza viruses in wild birds have a high possibility of spillover into domestic birds or mammals at the wild bird–domestic bird or bird–mammal interface. H8N4 viruses primarily circulate in migratory wild waterfowl and have rarely been identified in domestic birds. In this study, we summarized the spatial and temporal distribution of global H8 viruses, specified their natural reservoirs, and performed detailed evolutionary analysis onthe dominant H8N4 viruses. Here, we also report a novel H8N4 virus isolated from a Eurasian coot sample froma wetland in eastern China in 2022. Animal infection studies indicated that the wild bird-originated H8N4 virus can replicate and transmit efficiently in ducks but has not adapted to chickens. Additionally, this naturally isolated H8N4 virus can replicate in mice without prior adaptation. These results indicate that H8 viruses exist mainly in the wild duck reservoir and pose a high infection risk to domestic ducks. Therefore, the active surveillance of influenza viruses at the wild and domestic waterfowl interface will contribute to monitoring the circulation of these viruses.
基金supported by the National Natural Science Foundation of China(12172281,11972284 and 11872303)Fund for Distinguished Young Scholars of Shaanxi Province(2019JC-29)+1 种基金Foundation Strengthening Programme Technical Area Fund(2021-JCJQ-JJ-0565)Fund of the Youth Innovation Team of Shaanxi Universities and the Open Foundation of State Key Laboratory of Structural Analysis of Industrial Equipment(GZ19103).
文摘Although the complex structure-preserving method presented in our previous studies can be used to investigate the orbit–attitude–vibration coupled dynamic behaviors of the spatial flexible damping beam,the simulation speed still needs to be improved.In this paper,the infinite-dimensional dynamic model describing the orbit–attitude–vibration coupled dynamic problem of the spatial flexible damping beam is pretreated by the method of separation of variables,and the second-level fourth-order symplectic Runge–Kutta scheme is constructed to investigate the coupling dynamic behaviors of the spatial flexible damping beam quickly.Compared with the simulation speed of the complex structure-preserving method,the simulation speed of the symplectic Runge–Kutta method is faster,which benefits from the pretreatment step.The effect of the initial radial velocity on the transverse vibration as well as on the attitude evolution of the spatial flexible damping beam is presented in the numerical examples.From the numerical results about the effect of the initial radial velocity,it can be found that the appearance of the initial radial velocity can decrease the vibration frequency of the spatial beam and shorten the evolution interval for the attitude angle to tend towards a stable value significantly.In addition,the validity of the numerical results reported in this paper is verified by comparing with some numerical results presented in our previous studies.
基金funded by National Natural Science Foundation of China(No.31902421).
文摘Background Ulcerative colitis(UC)is a chronic,relapsing inflammatory bowel disease with complex aetiology and limited treatment options.Antimicrobial peptides(AMPs),as endogenous immune effectors,have recently emerged as promising therapeutic agents in UC.However,systematic identification and functional evaluation of AMPs remain underexplored.We aimed to discover novel AMPs with potential therapeutic efficacy in UC by leveraging machine learning-based prediction and validating their impact in an experimental colitis model.Methods We established a machine learning-driven pipeline to predict candidate AMPs based on their structural and functional features.Top-ranked peptides were synthesised and subjected to in vitro antibacterial assays and proteolytic stability tests.Their therapeutic potential was evaluated using a dextran sulfate sodium(DSS)-induced colitis mouse model,assessing clinical indicators,histopathology,inflammatory markers and gut microbiota alterations.Metagenomic and metabolomic analyses provided insights into microbial community dynamics and metabolic pathways.To probe the role of gut microbes in AMP-mediated gut homeostasis,we conducted Akkermansia(A.)muciniphila replenishment experiments.Results Several AMPs identified by machine learning exhibited potent antimicrobial activity and resistance to proteolytic degradation.In vivo,AMP administration ameliorated DSS-induced colitis symptoms,including body weight loss,Disease Activity Index and histological damage.Treatment also modulated the gut microbiome,increasing the abundance of A.muciniphila and restoring microbial balance.Functional metagenomic profiling revealed enrichment of genes involved in mucosal barrier protection and immunoregulation.These findings were supported by improved inflammatory cytokine profiles and enhanced epithelial integrity.Conclusions Our findings demonstrate that machine learning-guided discovery of AMPs is a viable approach to identify promising therapeutic agents for UC.By integrating multi-omics analyses,we reveal potential microbiota-mediated mechanisms underlying AMP efficacy.These insights provide a strong foundation for advancing AMP-based strategies in UC management.
基金supported by the National and Jiangsu Province NSF(T2293691,BK20212008)of ChinaNational Key Research and Development Program of China(2019YFA0705400)+2 种基金the Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(MCMS-I-0422K01)the Fundamental Research Funds for the Central Universities(NC2023001,NJ2023002,NJ2022002)the Fund of Prospective Layout of Scientific Research for Nanjing University of Aeronautics and Astronautics(NUAA).
文摘Random loadings(RL)are prevalent in mechanical systems,yet their inherent stochasticity poses significant challenges to structural fatigue reliability assessment.In this study,a three-dimensional fatigue reliability model is developed under RL through amplitude modulating and Fourier transformation.The non-Gaussian RL characteristics are accurately characterized by employing power spectral density and loading kurtosis.The equivalent initial crack size distributions are evaluated through three-dimensional fatigue growth theory by joint use of the standard fatigue stress-life(S-N)data and the fatigue crack growth data of the materials.Fatigue life distributions in specimens made of different materials with different geometries and thicknesses are analyzed under RL.It is shown that fatigue life exhibits negative correlations with power spectral density,kurtosis,and initial crack size.Especially,it is found that fatigue life and kurtosis approximately follow a power–law relationship,with both mean and variance decreasing as kurtosis increases.Validations against the experimental data available in the literature show that the present model can provide an efficient prediction of the fatigue life of mechanical systems under RL with limited experiment data.
基金supported by the Science and Technology Programme of Changzhou City,Jiangsu Province(CE20235002)the Science and Technology Programme of Changzhou City,Jiangsu Province(CQ20230004)the Science and Technology Programme of Changzhou City,Jiangsu Province(CQ20230005).
文摘Intrauterine adhesion(IUA)is a prevalent complication arising from uterine surgery,significantly impacting women’s fertility and overall quality of life.The conventional clinical approach involves hysteroscopic separation of uterine adhesions,though this method poses operational challenges and carries risks of postop-erative re-adhesion.Alternatively,the intraoperative placement of intrauterine devices or support balloons can act as a physical barrier to prevent adhesion formation.However,its effectiveness is limited and it may result in secondary damage to the endothe-lial tissue.To tackle these challenges,we have engineered a temperature-responsive hydrogel incorporating Pluronic HP407/HP188 pharmaceutical excipients and recombinant typeⅢcollagen(rColⅢ)as a bioactive element.Upon in situ injection into the uterine cavity,this hydrogel transitions from a sol–gel phase to a gel in response to body temperature changes,thereby minimizing nonspecific distribution and prolonging the duration of treatment.In vitro studies demonstrate that rColⅢtemperature-responsive hydrogels ex-hibit favorable biocompatibility,exhibit a recruitment effect on human endometrial stromal cells,suppress the expression of the fibrotic factor transforming growth factor beta 1 and promote angiogenesis.To evaluate its efficacy in preventing IUA via in vivo experiments,we employed sexually mature female rats for IUA modeling and compared its performance with a commercially available product,cross-linked sodium hyaluronate gel.The results indicate that rColⅢtemperature-responsive hydrogels significantly enhance retention at the injury site,substantially promote endometrial regeneration,augment endometrial blood supply and reduce abnormal fibrin depo-sition.This study suggests that rColⅢtemperature-responsive hydrogels can effectively prevent post-surgical uterine adhesions,highlighting their potential as a promising adhesion prevention strategy.
基金supported by the National Natural Science Foundation of China(Nos.U2341249,12005076,22205112)the Fundamental Research Funds for the Central Universities(No.2025201012)。
文摘The presence of a surface oxide film(B_(2)O_(3))on boron(B)particles significantly compromises their combustion efficiency and kinetic performance in fuel-rich solid propellants.This study proposes an innovative continuous modification strategy combining non-thermal plasma(NTP)etching with fluorocarbon passivation.Characterization and kinetic analysis revealed that reactive plasma species—including atomic hydrogen(H),electronically excited molecular hydrogen(H_(2)^(*)),vibrationally excited molecular hydrogen(H_(2)v),and hydrogen ions(H^(+))—dominate the reduction of B_(2)O_(3)through lowering the transition energy barrier and shifting the reaction spontaneity.Subsequent argon plasma fragmentation of C_(8)F_(18)generates fluorocarbon radicals that form conformal passivation coatings(thickness:7 nm)on purified boron surfaces.The modified boron particles exhibit 37.5℃lower exothermic peak temperature and 27.2%higher heat release(14.8 kJ/g vs.11.6 kJ/g)compared to untreated counterparts.Combustion diagnostics reveal 194%increase in maximum flame height(135.10 mm vs.46.03 mm)and 134%enhancement in flame propagation rate(4.44 cm/s vs.1.90 cm/s).This NTP-based surface engineering approach establishes a scalable pathway for developing highperformance boron-based energetic composites.
基金supported by the National Natural Science Foundation of China (31521005, 31672593)the Laboratory for Lingnan Modern Agriculture Project (NT2021007)+1 种基金the National Key Research and Development Program of China (2016YFD0500201)the China Agriculture Research System (CARS-41G12)
文摘The H5N8 avian influenza viruses have been widely circulating in wild birds and are responsible for the loss of over 33 million domestic poultry in Europe, Russia, Middle East, and Asia since January 2020. To monitor the invasion and spread of the H5N8 virus in China, we performed active surveillance by analyzing 317 wild bird samples and swab samples collected from 41,172 poultry all over the country. We isolated 22 H5N8 viruses from wild birds and 14 H5N8 viruses from waterfowls. Genetic analysis indicated that the 36 viruses formed two different genotypes: one genotype viruses were widely detected from different wild birds and domestic waterfowls;the other genotype was isolated from a whopper swan. We further revealed the origin and spatiotemporal spread of these two distinct H5N8 virus genotypes in 2020 and 2021. Animal studies indicated that the H5N8 isolates are highly pathogenic to chickens, mildly pathogenic in ducks, but have distinct pathotypes in mice. Moreover, we found that vaccinated poultry in China could be completely protected against H5N8 virus challenge. Given that the H5N8 viruses are likely to continue to spread in wild birds, vaccination of poultry is highly recommended in high-risk countries to prevent H5N8 avian influenza.
基金supported by the National Key R&D Program of China (2016YFD0500201, 2016YFD0500203)the National Natural Science Foundation of China (31521005)the China Agriculture Research System (CARS-41-G12)
文摘Dear Editor, Live poultry markets are the major trading system of poultry in China and many other countries, and are also thought to be important for the generation and spread of avian influenza viruses and other avian pathogens (Zhang et al., 2013;Shi et al., 2017;Quan et al., 2018).
基金the National Natural Science Foundation of China(Grant Nos.81573369,21301191,81570696 and 31270985)the Natural Science Foundation of Jiangsu Province,China(Grant Nos.BK20130661 and BK20140659)the Research and Innovation Project of Jiangsu Province(Grant No.KYLX15_0640)
文摘Biodegradable polyamines have long been studied as potential recombinant viral gene vectors.Spermine(SPE) is an endogenous tetra-amine with excellent biocompatibility yet poor gene condensation capacity. We have previously synthesized a polyspermine based on SPE and poly(ethylene glycol)(PEG)diacrylate(SPE-alt-PEG) for enhanced transfection performance, but the synthesized SPE-alt-PEG still lacked specificity towards cancer cells. In this study, folic acid(FA) was incorporated into SPE-alt-PEG to fabricate a targeted gene delivery vector(FA-SPE-PEG) via an acylation reaction. FA-SPE-PEG exhibited mild cytotoxicity in both cancer cells and normal cells. FA-SPE-PEG possessed higher transfection efficiency than PEI 25 K and Lipofectamines2000 in two tested cancer cell lines at functional weight ratios, and its superiority over untargeted SPE-alt-PEG was prominent in cells with overexpressed folate receptors(FRs). Moreover, in vivo delivery of green fluorescent protein(GFP) with FA-SPE-PEG resulted in highest fluorescent signal intensity of all investigated groups. FA-SPE-PEG showed remarkably enhanced specificity towards cancer cells both in vivo and in vitro due to the interaction between FA and FRs. Taken together, FA-SPE-PEG was demonstrated to be a prospective targeted gene delivery vector with high transfection capacity and excellent biocompatibility.
基金financially supported under Guangzhou Science and Technology Plan Project (No.202201010108)CAS Science and Technology Service Network Program Project (No.20211600200082)Guangzhou Development Zone International Science and Technology Cooperation Project Funding (No.2021GH07).
文摘The increasing power density of IT electronics and the enormous energy consumption of data centers lead to the urgent demand for efficient cooling technology.Due to its efficiency and safety,liquid-cooled heat sink technology may gradually replace air-cooled technology over time.With the ambient or higher water supply temperature,the liquid-cooled technology shortens the operating time of the chiller and improves its coefficient of performance,while the pump power consumption may increase for satisfying the constant cooling capacity.Therefore,it is significant to study the optimal water supply temperature to achieve energy-efficient operation of data centers.A virtual 30.1 kW data center is considered as the case,the liquid-cooled system is constructed with a combination of innovative manifold microchannel heat sink with oblique fins and indirect evaporative cooling technology to minimize energy consumption.A hybrid thermal management model integrating the heat dissipation model and the power consumption model is established by TRNSYS and FLUENT software.To the highest chip-safe operating temperature premise,the energy performance is analyzed under various water supply temperatures in Guangzhou.The result shows that only 21.5-hour mechanical cooling is needed with the 30℃server inlet temperature throughout the year.And the minimized power consumption occurs with the constant 29℃server inlet temperature.Moreover,the temperature adaptive control strategy(TACS)is adopted to test the cooling system power consumption under different regulation frequencies,and the by-week TACS can achieve another 11.5%energy saving than the minimum power consumption of the constant temperature control strategy.
基金supported by the National Natural Science Foundation of China(No.21801012 to G.L.X.).
文摘Supported Pd catalysts show superior activities for olefin productions from alkynes through semi-hydrogenation reactions,but over-hydrogenation into alkanes highly decreases olefin selectivity.Using phenylacetylene semi-hydrogenation as a model reaction,here we explore the optimization approaches toward better Pd catalysts for alkyne semi-hydrogenation through investigating support effect and metal-support interactions.The results show that the states of Pd with supports can be tuned by varying oxide reducibility,loading ratios,and post-treatments.In our system,0.06 wt.%Pd on rutile-TiO_(2) nanorods shows the highest activity owing to the synergistic effects of single-atoms and clusters.Support reducibility can change the filling degrees of Pd 4d orbitals through varying interfacial bonding strengths,which further affect catalytic activity and selectivity.
基金supported by the National Key Research and Development Program of China(2023YFE0203500)the National Natural Science Foundation of China(82003670)+2 种基金Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX23_1449)the National Natural Science Foundation of China(22375026)Jiangsu Province College Student Innovation and Entrepreneurship Training Program Project(202310292053Z).
文摘The incidence of intrauterine adhesions(IUA)has increased with the rising utilization of intrauterine surgery.The postoperative physical barrier methods commonly used,such as balloons and other fillers,have limited effectiveness and may even cause further damage to the remaining endometrial tissue.Herein,we developed an injectable thermosensitive hydrogel using Pluronic F127/F68 as pharmaceutical excipients and curcumin as a natural active molecule.The hydrogel effectively addresses solubility and low bioavailability issues associated with curcumin.In vitro,drug release assays revealed that the amorphous curcumin hydrogel promotes dissolution and sustained release of curcumin.In vitro experiments reveal high biocompatibility of the hydrogel and its ability to enhance vascular formation while inhibiting the expression of fibrotic factor TGF-β1.To assess the effectiveness of preventing IUAs,in vivo experiments were conducted using IUA rats and compared with a class III medical device,a new-crosslinked hyaluronic acid(NCHA)gel.According to the study,curcumin hydrogel is more effective than the NCHA group in improving the regeneration of the endometrium,increasing the blood supply to the endometrium and reducing the abnormal deposition of fibrin,thus preventing IUA more effectively.This study provides a promising strategy for treating and preventing IUA.
基金supported by the National Key Research and Development Program of China(Grant No.2019YFA0705400)the Natural Science Foundation of Jiangsu Province(Grant No.BK20212008)+2 种基金the Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures(Grant No.MCMS-I-0421K01)the Fundamental Research Funds for the Central Universities(Grant Nos.NJ2020003,and NZ2020001)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘In creeping solids,plane stress and plane strain solutions for asymptotic singular crack-tip fields have been first put forward by Riedel and Rice with C^(*)as the dominating parameter and developed by Xiang and Guo into three-dimensional solution(3D)for stationary cracks under the domination of C^(*)with the constraint factor Tz.However,how to characterize the 3D crack-tip fields under creep damage-induced quasistatic growing conditions remains challenging.In this study,we reveal that,for 3D quasistatic growing cracks,the leading singular solution can effectively characterize the crack-tip stress distributions with relative errors less than 10.8%for relative creep time up to 0.8 in various specimens with finite thickness.For a given relative time,Tz distributions can be unified by the equivalent thickness concept,Beq.The results show that C^(*)-T_(z) can effectively quantify both the load and constraint effects on the crack-tip fields.Such geometry independent dominance can considerably simplify the treatments of load and constraint effects,thereby promoting the application of fracture mechanics in high-temperature damage tolerance designs.
