The development of modern agriculture requires the reduction of water and chemical N fertilizer inputs.Increasing the planting density can maintain higher yields,but also consumes more of these restrictive resources.H...The development of modern agriculture requires the reduction of water and chemical N fertilizer inputs.Increasing the planting density can maintain higher yields,but also consumes more of these restrictive resources.However,whether an increased maize density can compensate for the negative effects of reduced water and N supply on grain yield and N uptake in the arid irrigated areas remains unknown.This study is part of a long-term positioning trial that started in 2016.A split-split plot field experiment of maize was implemented in the arid irrigated area of northwestern China in 2020 to 2021.The treatments included two irrigation levels:local conventional irrigation reduced by 20%(W1,3,240 m^(3)ha^(-1))and local conventional irrigation(W2,4,050 m^(3)ha^(-1));two N application rates:local conventional N reduced by 25%(N1,270 kg ha^(-1))and local conventional N(360 kg ha^(-1));and three planting densities:local conventional density(D1,75,000 plants ha^(-1)),density increased by 30%(D2,97,500 plants ha-1),and density increased by 60%(D3,120,000 plants ha^(-1)).Our results showed that the grain yield and aboveground N accumulation of maize were lower under the reduced water and N inputs,but increasing the maize density by 30% can compensate for the reductions of grain yield and aboveground N accumulation caused by the reduced water and N supply.When water was reduced while the N application rate remained unchanged,increasing the planting density by 30% enhanced grain yield by 13.9% and aboveground N accumulation by 15.3%.Under reduced water and N inputs,increasing the maize density by 30% enhanced N uptake efficiency and N partial factor productivity,and it also compensated for the N harvest index and N metabolic related enzyme activities.Compared with W2N2D1,the N uptake efficiency and N partial factor productivity increased by 28.6 and 17.6%under W1N1D2.W1N2D2 had 8.4% higher N uptake efficiency and 13.9% higher N partial factor productivity than W2N2D1.W1N2D2 improved urease activity and nitrate reductase activity by 5.4% at the R2(blister)stage and 19.6% at the V6(6th leaf)stage,and increased net income and the benefit:cost ratio by 22.1 and 16.7%,respectively.W1N1D2 and W1N2D2 reduced the nitrate nitrogen and ammoniacal nitrogen contents at the R6 stage in the 40-100 cm soil layer,compared with W2N2D1.In summary,increasing the planting density by 30% can compensate for the loss of grain yield and aboveground N accumulation under reduced water and N inputs.Meanwhile,increasing the maize density by 30% improved grain yield and aboveground N accumulation when water was reduced by 20% while the N application rate remained constant in arid irrigation areas.展开更多
The efficacy and safety of recombinant tissue plasminogen activator （rtPA） need to be improved due to its low bioavailability and requirement of large dose administration. The purpose of this study was to develop a ...The efficacy and safety of recombinant tissue plasminogen activator （rtPA） need to be improved due to its low bioavailability and requirement of large dose administration. The purpose of this study was to develop a fibrin-targeted nanoparticle （NP） drug delivery system for thrombosis combination therapy. We conjugated rtPA to poly（ethylene glycol）- poly（ε-caprolactone） （PEG-PCL） nanoparticles （rtPA-NP） and investigated its physicochemical characteristics such as particle size, zeta potential, enzyme activity of conjugated rtPA and its storage stability at 4℃. The thrombolytic activity of rtPA-NP was evaluated in vitro and in vivo as well as the half-life of rtPA-NP, the properties to fibrin targeting and its influences on systemic hemostasis in vivo. The results showed that rtPA-NP equivalent to 10% of a typical dose of rtPA could dissolve fibrin clots and were demonstrated to have a neuroprotective effect after focal cerebral ischemia as evidenced by decreased infarct volume and improved neurological deficit （P〈0.001）. RtPA-NP did not influence the in vivo hemostasis or coagulation system. The half-life of conjugated rtPA was shown to be approximately 18 times longer than that of free rtPA. These experiments suggested that rtPA-conjugated PEG-PCL nanoparticles might be a promising fibrin-targeted delivery system for a combination treatment of thrombosis.展开更多
Objective To study the effects of electromagnetic pulse （EMP） on bone metabolism of mice in vivo. Methods Twenty-four male BALB/c mice were divided into a control group and 2 experimental groups （n=8）. The whole-b...Objective To study the effects of electromagnetic pulse （EMP） on bone metabolism of mice in vivo. Methods Twenty-four male BALB/c mice were divided into a control group and 2 experimental groups （n=8）. The whole-body of mice in experimental groups were exposed to 50 kV/m and 400kV/m EMP, 400 pulses daily for 7 consecutive days at 2 seconds intervals. Alkaline phosphotase （ALP） activity, serum calcium concentration and osteocalcin level and trabecular bone volume （BV/TV, %） were measured immediately after EMP exposure by biochemical, ELISA and morphological methods. Results The ALP activity, serum calcium concentration and osteocalcin level and BV/TV in experimental groups remained unchanged after EMP exposure. Conelusion Under our experimental conditions, EMP exposure cannot affect bone metabolism of mice in vivo.展开更多
Photocatalytic reduction of CO_(2) is considered as a kind of promising technologies for solving the greenhouse effect.Herein,a novel hybrid structure of g-C_(3)N_(4)/ZnO/Ti_(3)C_(2) photocatalysts was designed and fa...Photocatalytic reduction of CO_(2) is considered as a kind of promising technologies for solving the greenhouse effect.Herein,a novel hybrid structure of g-C_(3)N_(4)/ZnO/Ti_(3)C_(2) photocatalysts was designed and fabricated to investigate their abilities for CO_(2) reduction.As demonstration,heterojunction of g-C_(3)N_(4)/ZnO can improve photogenerated carriers’separation,the addition of Ti_(3)C_(2) fragments can further facilitate the photocatalytic performance from CO_(2) to CO.Hence,g-C_(3)N_(4)/ZnO/Ti_(3)C_(2) has efficiently increased CO production by 8 and 12 times than pristine g-C_(3)N_(4) and ZnO,respectively.Which is ascribed to the photogenerated charge migration promoted by metallic Ti_(3)C_(2).This work provides a guideline for designing efficient hybrid catalysts on other applications in the renewable energy fields.展开更多
The double drum coal shearer is widely applied for the underground coal exploration in the mining industry.The vibration and noise control are significant factors for the stability design of the double drum coal shear...The double drum coal shearer is widely applied for the underground coal exploration in the mining industry.The vibration and noise control are significant factors for the stability design of the double drum coal shearer.In this paper,the vibration properties of a double drum coal shearer are firstly investigated.The horizontal,transverse and torsional vibrations of the motor body and the angle displacements of the rockers are taken into account.The walking units and the hydraulic units are modeled by the stiffness-damping systems.The nonlinear equation of motion of the double drum coal shearer is established by applying the Lagrange’s equation.The nonlinear vibration response of the system is calculated by using the Runge Kutta numerical method.The effects of the shearing loads,the equivalent damping and stiffness of the walking units,the inclination angels of the rockers and the equivalent damping and stiffness of the hydraulic units on the vibration properties of the system are discussed.展开更多
本文以软骨力学为主题词,在Web of Science数据库中检索并下载期刊文献,分别使用知识图谱软件CiteSpace和VOSviewer对作者、国家及地区、机构和关键词共现及聚类等进行信息可视化分析,探索该领域近5年的发展状况、研究热点及前沿。结果...本文以软骨力学为主题词,在Web of Science数据库中检索并下载期刊文献,分别使用知识图谱软件CiteSpace和VOSviewer对作者、国家及地区、机构和关键词共现及聚类等进行信息可视化分析,探索该领域近5年的发展状况、研究热点及前沿。结果表明软骨力学在骨关节炎等疾病中,对再生医学和组织工程领域具有重要作用,为下一步开展更深层次的研究工作提供理论基础。展开更多
Carbon/carbon composites with higher mechanical strength and better reliability at elevated tempera-tures are urgently needed to satisfy the practical applications requirements.SiC nanowires(SiCNWs)modified C/C(SC-CC)...Carbon/carbon composites with higher mechanical strength and better reliability at elevated tempera-tures are urgently needed to satisfy the practical applications requirements.SiC nanowires(SiCNWs)modified C/C(SC-CC)composites have attracted an abundance of attention for their excellent mechanical performance.To further boost the mechanical strengths of composites and maximize the reinforcing efficiency of SiCNWs,we introduce orthogonally structured graphene nanosheets(OGNs)into SC-CC composites,in which OGNs are grafted on the SiCNWs via chemical vapor deposition(CVD)method,forming SC-G-CC composites.Benefiting from the nano-interface effects,uniform stress distribution,strong SiCNWs/PyC interfacial bonding and elevated stress propagation efficiency in the PyC matrix are achieved,thus SC-G-CC composites accomplish brilliant mechanical properties before and after 1,600℃ heat treatment.As temperature rises to 2,100℃,SiCNWs lose efficacy,whereas OGNs with excellent thermal stability continue to play the nano-interface role in the PyC matrix.Therefore,SC-G-CC com-posites show better mechanical performance after 2,100℃ heat treatment,and the mechanical strength retention rate(MSR)of interlaminar shear strength,out-of-plane and in-plane compressive strength of SC-G-CC composites reach 61.0%,55.7%and 55.3%,respectively.This work proposes an alternative thought for maximizing the potentiality of nanomaterials and edifies the mechanical modification of composites.展开更多
Artificial intelligence(AI)is gradually changing the practice of surgery with technological advancements in imaging,navigation,and robotic intervention.In this article,we review the recent successful and influential a...Artificial intelligence(AI)is gradually changing the practice of surgery with technological advancements in imaging,navigation,and robotic intervention.In this article,we review the recent successful and influential applications of AI in surgery from preoperative planning and intraoperative guidance to its integration into surgical robots.We conclude this review by summarizing the current state,emerging trends,and major challenges in the future development of AI in surgery.展开更多
Extensive attention has been drawn to the development of carbon fiber composites for their application in brake disks due to the increasing demand for brake disks with high mechanical strength and better tribological ...Extensive attention has been drawn to the development of carbon fiber composites for their application in brake disks due to the increasing demand for brake disks with high mechanical strength and better tribological properties.Herein,we design SiC hexagonal nanopyramids modified carbon/carbon(SiCNPsC/C)composites,in which SiCNPs are radially grafted on the carbon fibers by the combined sol-gel and carbothermal reduction method,and pyrolytic carbon(Py C)matrix is deposited on nucleation sites including carbon fibers and SiCNPs by isothermal chemical vapor infiltration(ICVI).Benefiting from the special structure,SiCNPs-C/C composites exhibit superior mechanical and frictional performance.Compared with C/C composites,SiCNPs-C/C composites have 147%,90.3%,70.6%,and 117.9%improvement in the hardness,interlaminar shear strength,and out-of-plane and in-plane compressive strength,respectively,which is attributed to the optimized fiber/matrix(F/M)interfaces bonding and the enhanced cohesion strength of Py C matrix.In addition,the friction coefficient of SiCNPs-C/C composites increases by 25.5%,and the wear rate decreases by 38.0%.This work provides an optional design thought for the nanomaterials and enlightens the mechanical and frictional modification of composites in the field of the brakes.展开更多
Extensive attention has been drawn to the development of carbon-matrix composites for application in the aerospace and military industry,where a combination of high mechanical strength and excellent frictional propert...Extensive attention has been drawn to the development of carbon-matrix composites for application in the aerospace and military industry,where a combination of high mechanical strength and excellent frictional properties are required.Herein,carbon-matrix composites reinforced by Si_(3)N_(4)nanowires@pyrolytic carbon nanolayers(Si_(3)N_(4nws)@PyCnls)coupled with hydroxyapatite nanosheets is reported.The Si_(3)N_(4nws)@PyCnls(SP)with coaxial structure could increase the surface roughness of Si_(3)N_(4nws)and promote the stress transfer to the carbon matrix,whereas the porous hydroxyapatite nanosheets favor the infiltration of the carbon matrix and promote the interfacial bonding between the SP and carbon matrix.The carbon matrix composites reinforced by SP coupled with hydroxyapatite nanosheets(Si_(3)N_(4nws)@PyCnls-HA-C)exhibit excellent mechanical strength.Compare with the conventional Si_(3)N_(4nws)reinforced carbon composites,Si_(3)N_(4nws)@PyCnls-HA-C(SPHC)have 162%and 249%improvement in flexural strength and elastic modulus,respectively.Moreover,the friction coefficient and wear rate decreased by 53%and 23%,respectively.This study provides a co-reinforcement strategy generated by SP coupled with hydroxyapatite nanosheets for effective improvement of mechanical and frictional properties of carbon matrix composites that are used for aerospace and military industry applications.展开更多
Constructed wetlands are commonly utilized to treat industrial wastewater due to their effectiveness,affordability,and environmental benefits.Many phosphorus chemical enterprises in the middle Yangtze River basin are ...Constructed wetlands are commonly utilized to treat industrial wastewater due to their effectiveness,affordability,and environmental benefits.Many phosphorus chemical enterprises in the middle Yangtze River basin are facing high pollution load challenges and efforts are needed to improve removal efficiency of pollutants.This work was the first to use constructed wetlands for phosphorus chemical industry tailwater(PCITW)treatment.The new hybrid constructed wetlands(CWs)proposed were the aeration horizontal subsurface flow constructed wetland(AHSCW)and the integrated vertical flow constructed wetland(IVCW),which were constructed on a pilot scale.Here,the effectiveness of pollutant removal along hybrid CWs,wetland plant growth,and rootassociated microbial community responses to the PCITW were investigated.The results showed that there was spatial variation in removal of carbon,nitrogen,and phosphorus in the hybrid CWs,and that the AHSCW and the IVCW played synergistic roles in the removal of pollutants.Compared with influent,the toxic effect of effluent to embryos of a rare minnow(Gobiocypris rarus)was alleviated.Exposure to the effluent resulted in no malformation or death for embryos.Plants and microorganisms in the wetland system of the phosphate chemical tailwater were then compared with the control system of municipal tailwater.Plants in the former system had lower root density,and higher average root diameter,root shoot ratio,specific root length,and specific surface area.Plant roots also had decreased NH_(4)^(+)uptake ability but increased Ca^(2+)uptake to adapt to the high load and complex pollution stress.Unlike the control system,stochastic mechanisms had a more important role than deterministic processes in shaping the microbial community assembly associated with the PCITW.Meanwhile,analysis of microbial network-level topological characteristics demonstrated substantial reduction in network interactions complexity and microbiome stability in the treatment system.Findings from this study suggest wetlands will be helpful for efficient purification of phosphorus chemical industry wastewater in the Yangtze River basin.展开更多
Cognitive impairment is a multifactorial and multi-step pathological process that places a heavy burden on patients and the society.Neuroinflammation is one of the main factors leading to cognitive impairment.The infl...Cognitive impairment is a multifactorial and multi-step pathological process that places a heavy burden on patients and the society.Neuroinflammation is one of the main factors leading to cognitive impairment.The inflammasomes are multi-protein complexes that respond to various microorganisms and endogenous danger signals,helping to initiate innate protective responses in inflammatory diseases.NLRP3 inflammasomes produce proinflammatory cytokines(interleukin IL-1βand IL-18)by activating caspase-1.In this review,we comprehensively describe the structure and functions of the NLRP3 inflammasome.We also explore the intrinsic relationship between the NLRP3 inflammasome and cognitive impairment,which involves immune cell activation,cell apoptosis,oxidative stress,mitochondrial autophagy,and neuroinflammation.Finally,we describe NLRP3 inflammasome antagonists as targeted therapies to improve cognitive impairment.展开更多
基金financial support of the National Natural Science Foundation of China(U21A20218 and 32101857)the‘Double First-Class’Key Scientific Research Project of Education Department in Gansu Province,China(GSSYLXM-02)+1 种基金the Fuxi Young Talents Fund of Gansu Agricultural University,China(Gaufx03Y10)the“Innovation Star”Program of Graduate Students in 2023 of Gansu Province,China(2023CXZX681)。
文摘The development of modern agriculture requires the reduction of water and chemical N fertilizer inputs.Increasing the planting density can maintain higher yields,but also consumes more of these restrictive resources.However,whether an increased maize density can compensate for the negative effects of reduced water and N supply on grain yield and N uptake in the arid irrigated areas remains unknown.This study is part of a long-term positioning trial that started in 2016.A split-split plot field experiment of maize was implemented in the arid irrigated area of northwestern China in 2020 to 2021.The treatments included two irrigation levels:local conventional irrigation reduced by 20%(W1,3,240 m^(3)ha^(-1))and local conventional irrigation(W2,4,050 m^(3)ha^(-1));two N application rates:local conventional N reduced by 25%(N1,270 kg ha^(-1))and local conventional N(360 kg ha^(-1));and three planting densities:local conventional density(D1,75,000 plants ha^(-1)),density increased by 30%(D2,97,500 plants ha-1),and density increased by 60%(D3,120,000 plants ha^(-1)).Our results showed that the grain yield and aboveground N accumulation of maize were lower under the reduced water and N inputs,but increasing the maize density by 30% can compensate for the reductions of grain yield and aboveground N accumulation caused by the reduced water and N supply.When water was reduced while the N application rate remained unchanged,increasing the planting density by 30% enhanced grain yield by 13.9% and aboveground N accumulation by 15.3%.Under reduced water and N inputs,increasing the maize density by 30% enhanced N uptake efficiency and N partial factor productivity,and it also compensated for the N harvest index and N metabolic related enzyme activities.Compared with W2N2D1,the N uptake efficiency and N partial factor productivity increased by 28.6 and 17.6%under W1N1D2.W1N2D2 had 8.4% higher N uptake efficiency and 13.9% higher N partial factor productivity than W2N2D1.W1N2D2 improved urease activity and nitrate reductase activity by 5.4% at the R2(blister)stage and 19.6% at the V6(6th leaf)stage,and increased net income and the benefit:cost ratio by 22.1 and 16.7%,respectively.W1N1D2 and W1N2D2 reduced the nitrate nitrogen and ammoniacal nitrogen contents at the R6 stage in the 40-100 cm soil layer,compared with W2N2D1.In summary,increasing the planting density by 30% can compensate for the loss of grain yield and aboveground N accumulation under reduced water and N inputs.Meanwhile,increasing the maize density by 30% improved grain yield and aboveground N accumulation when water was reduced by 20% while the N application rate remained constant in arid irrigation areas.
基金This work was supported by the National Basic Scientific Research Program of China （973 Program, No. 2007CB935803）, the National Natural Science Foundation of China （No. 30825018） and the Key Clinical Program of the Ministry of Health of China （No. 2010439）.
文摘The efficacy and safety of recombinant tissue plasminogen activator （rtPA） need to be improved due to its low bioavailability and requirement of large dose administration. The purpose of this study was to develop a fibrin-targeted nanoparticle （NP） drug delivery system for thrombosis combination therapy. We conjugated rtPA to poly（ethylene glycol）- poly（ε-caprolactone） （PEG-PCL） nanoparticles （rtPA-NP） and investigated its physicochemical characteristics such as particle size, zeta potential, enzyme activity of conjugated rtPA and its storage stability at 4℃. The thrombolytic activity of rtPA-NP was evaluated in vitro and in vivo as well as the half-life of rtPA-NP, the properties to fibrin targeting and its influences on systemic hemostasis in vivo. The results showed that rtPA-NP equivalent to 10% of a typical dose of rtPA could dissolve fibrin clots and were demonstrated to have a neuroprotective effect after focal cerebral ischemia as evidenced by decreased infarct volume and improved neurological deficit （P〈0.001）. RtPA-NP did not influence the in vivo hemostasis or coagulation system. The half-life of conjugated rtPA was shown to be approximately 18 times longer than that of free rtPA. These experiments suggested that rtPA-conjugated PEG-PCL nanoparticles might be a promising fibrin-targeted delivery system for a combination treatment of thrombosis.
基金supported by the Research Fund of National Natural Science Foundation of China (No.30800928,No.30670492)the National 863 Project (No.2006 AA02Z4C3)
文摘Objective To study the effects of electromagnetic pulse （EMP） on bone metabolism of mice in vivo. Methods Twenty-four male BALB/c mice were divided into a control group and 2 experimental groups （n=8）. The whole-body of mice in experimental groups were exposed to 50 kV/m and 400kV/m EMP, 400 pulses daily for 7 consecutive days at 2 seconds intervals. Alkaline phosphotase （ALP） activity, serum calcium concentration and osteocalcin level and trabecular bone volume （BV/TV, %） were measured immediately after EMP exposure by biochemical, ELISA and morphological methods. Results The ALP activity, serum calcium concentration and osteocalcin level and BV/TV in experimental groups remained unchanged after EMP exposure. Conelusion Under our experimental conditions, EMP exposure cannot affect bone metabolism of mice in vivo.
基金supported by National Natural Science Foundation of China(Grant No.11804005,11375136,12204014)Anyang Institute of Technology Research Cultivation Fund(Grant No.YPY2019002)。
文摘Photocatalytic reduction of CO_(2) is considered as a kind of promising technologies for solving the greenhouse effect.Herein,a novel hybrid structure of g-C_(3)N_(4)/ZnO/Ti_(3)C_(2) photocatalysts was designed and fabricated to investigate their abilities for CO_(2) reduction.As demonstration,heterojunction of g-C_(3)N_(4)/ZnO can improve photogenerated carriers’separation,the addition of Ti_(3)C_(2) fragments can further facilitate the photocatalytic performance from CO_(2) to CO.Hence,g-C_(3)N_(4)/ZnO/Ti_(3)C_(2) has efficiently increased CO production by 8 and 12 times than pristine g-C_(3)N_(4) and ZnO,respectively.Which is ascribed to the photogenerated charge migration promoted by metallic Ti_(3)C_(2).This work provides a guideline for designing efficient hybrid catalysts on other applications in the renewable energy fields.
基金Projects(51975511,U1708254)supported by the National Natural Science Foundation of ChinaProject(N2003023)supported by the Fundamental Research Funds for the Central Universities of China+1 种基金Project(2019YFB2004400)supported by the National Key Research and Development Program of ChinaProject(2020-MS-092)supported by the Natural Science Foundation of Liaoning Province,China。
文摘The double drum coal shearer is widely applied for the underground coal exploration in the mining industry.The vibration and noise control are significant factors for the stability design of the double drum coal shearer.In this paper,the vibration properties of a double drum coal shearer are firstly investigated.The horizontal,transverse and torsional vibrations of the motor body and the angle displacements of the rockers are taken into account.The walking units and the hydraulic units are modeled by the stiffness-damping systems.The nonlinear equation of motion of the double drum coal shearer is established by applying the Lagrange’s equation.The nonlinear vibration response of the system is calculated by using the Runge Kutta numerical method.The effects of the shearing loads,the equivalent damping and stiffness of the walking units,the inclination angels of the rockers and the equivalent damping and stiffness of the hydraulic units on the vibration properties of the system are discussed.
文摘本文以软骨力学为主题词,在Web of Science数据库中检索并下载期刊文献,分别使用知识图谱软件CiteSpace和VOSviewer对作者、国家及地区、机构和关键词共现及聚类等进行信息可视化分析,探索该领域近5年的发展状况、研究热点及前沿。结果表明软骨力学在骨关节炎等疾病中,对再生医学和组织工程领域具有重要作用,为下一步开展更深层次的研究工作提供理论基础。
基金supported by the National Natural Science Foundation of China(Grant No.52222204)the Joint Funds of the National Natural Science Foundation of China(Grant No.U21B2067)+2 种基金the Key R&D Program of Shaanxi Province(Grant Nos.2019ZDLGY04-02 and 2021ZDLGY14-04)Natural Science Basic Research Plan in Shaanxi(2022JC-25)GuangDong Basic and Applied Basic Research Foundation(2022A1515111220).
文摘Carbon/carbon composites with higher mechanical strength and better reliability at elevated tempera-tures are urgently needed to satisfy the practical applications requirements.SiC nanowires(SiCNWs)modified C/C(SC-CC)composites have attracted an abundance of attention for their excellent mechanical performance.To further boost the mechanical strengths of composites and maximize the reinforcing efficiency of SiCNWs,we introduce orthogonally structured graphene nanosheets(OGNs)into SC-CC composites,in which OGNs are grafted on the SiCNWs via chemical vapor deposition(CVD)method,forming SC-G-CC composites.Benefiting from the nano-interface effects,uniform stress distribution,strong SiCNWs/PyC interfacial bonding and elevated stress propagation efficiency in the PyC matrix are achieved,thus SC-G-CC composites accomplish brilliant mechanical properties before and after 1,600℃ heat treatment.As temperature rises to 2,100℃,SiCNWs lose efficacy,whereas OGNs with excellent thermal stability continue to play the nano-interface role in the PyC matrix.Therefore,SC-G-CC com-posites show better mechanical performance after 2,100℃ heat treatment,and the mechanical strength retention rate(MSR)of interlaminar shear strength,out-of-plane and in-plane compressive strength of SC-G-CC composites reach 61.0%,55.7%and 55.3%,respectively.This work proposes an alternative thought for maximizing the potentiality of nanomaterials and edifies the mechanical modification of composites.
文摘Artificial intelligence(AI)is gradually changing the practice of surgery with technological advancements in imaging,navigation,and robotic intervention.In this article,we review the recent successful and influential applications of AI in surgery from preoperative planning and intraoperative guidance to its integration into surgical robots.We conclude this review by summarizing the current state,emerging trends,and major challenges in the future development of AI in surgery.
基金the National Natural Science Foundation of China(Nos.51872232,51972271,and 51872234)Natural Science Basic Research Plan in Shaanxi(No.2022JC-25)。
文摘Extensive attention has been drawn to the development of carbon fiber composites for their application in brake disks due to the increasing demand for brake disks with high mechanical strength and better tribological properties.Herein,we design SiC hexagonal nanopyramids modified carbon/carbon(SiCNPsC/C)composites,in which SiCNPs are radially grafted on the carbon fibers by the combined sol-gel and carbothermal reduction method,and pyrolytic carbon(Py C)matrix is deposited on nucleation sites including carbon fibers and SiCNPs by isothermal chemical vapor infiltration(ICVI).Benefiting from the special structure,SiCNPs-C/C composites exhibit superior mechanical and frictional performance.Compared with C/C composites,SiCNPs-C/C composites have 147%,90.3%,70.6%,and 117.9%improvement in the hardness,interlaminar shear strength,and out-of-plane and in-plane compressive strength,respectively,which is attributed to the optimized fiber/matrix(F/M)interfaces bonding and the enhanced cohesion strength of Py C matrix.In addition,the friction coefficient of SiCNPs-C/C composites increases by 25.5%,and the wear rate decreases by 38.0%.This work provides an optional design thought for the nanomaterials and enlightens the mechanical and frictional modification of composites in the field of the brakes.
基金his work was supported by the National Natural Science Foundation of China under Grant Nos.51872232the Research Fund of the State Key Laboratory of Solidification Processing(NWPU),China(Grant No.136-QP-2015),the“111”project of China(B08040)+1 种基金the National Training Program of Innovation and Entrepreneurship for Undergraduates(Grand No.S202010699336)Project supported by the Joint Funds of the National Natural Science Foundation of China(Grant No.U21B2067).
文摘Extensive attention has been drawn to the development of carbon-matrix composites for application in the aerospace and military industry,where a combination of high mechanical strength and excellent frictional properties are required.Herein,carbon-matrix composites reinforced by Si_(3)N_(4)nanowires@pyrolytic carbon nanolayers(Si_(3)N_(4nws)@PyCnls)coupled with hydroxyapatite nanosheets is reported.The Si_(3)N_(4nws)@PyCnls(SP)with coaxial structure could increase the surface roughness of Si_(3)N_(4nws)and promote the stress transfer to the carbon matrix,whereas the porous hydroxyapatite nanosheets favor the infiltration of the carbon matrix and promote the interfacial bonding between the SP and carbon matrix.The carbon matrix composites reinforced by SP coupled with hydroxyapatite nanosheets(Si_(3)N_(4nws)@PyCnls-HA-C)exhibit excellent mechanical strength.Compare with the conventional Si_(3)N_(4nws)reinforced carbon composites,Si_(3)N_(4nws)@PyCnls-HA-C(SPHC)have 162%and 249%improvement in flexural strength and elastic modulus,respectively.Moreover,the friction coefficient and wear rate decreased by 53%and 23%,respectively.This study provides a co-reinforcement strategy generated by SP coupled with hydroxyapatite nanosheets for effective improvement of mechanical and frictional properties of carbon matrix composites that are used for aerospace and military industry applications.
基金This work was supported by the Strategic Priority Research Program of Chinese Academy of Science(Grant no.XDA23040401).
文摘Constructed wetlands are commonly utilized to treat industrial wastewater due to their effectiveness,affordability,and environmental benefits.Many phosphorus chemical enterprises in the middle Yangtze River basin are facing high pollution load challenges and efforts are needed to improve removal efficiency of pollutants.This work was the first to use constructed wetlands for phosphorus chemical industry tailwater(PCITW)treatment.The new hybrid constructed wetlands(CWs)proposed were the aeration horizontal subsurface flow constructed wetland(AHSCW)and the integrated vertical flow constructed wetland(IVCW),which were constructed on a pilot scale.Here,the effectiveness of pollutant removal along hybrid CWs,wetland plant growth,and rootassociated microbial community responses to the PCITW were investigated.The results showed that there was spatial variation in removal of carbon,nitrogen,and phosphorus in the hybrid CWs,and that the AHSCW and the IVCW played synergistic roles in the removal of pollutants.Compared with influent,the toxic effect of effluent to embryos of a rare minnow(Gobiocypris rarus)was alleviated.Exposure to the effluent resulted in no malformation or death for embryos.Plants and microorganisms in the wetland system of the phosphate chemical tailwater were then compared with the control system of municipal tailwater.Plants in the former system had lower root density,and higher average root diameter,root shoot ratio,specific root length,and specific surface area.Plant roots also had decreased NH_(4)^(+)uptake ability but increased Ca^(2+)uptake to adapt to the high load and complex pollution stress.Unlike the control system,stochastic mechanisms had a more important role than deterministic processes in shaping the microbial community assembly associated with the PCITW.Meanwhile,analysis of microbial network-level topological characteristics demonstrated substantial reduction in network interactions complexity and microbiome stability in the treatment system.Findings from this study suggest wetlands will be helpful for efficient purification of phosphorus chemical industry wastewater in the Yangtze River basin.
基金supported by grants from the doctoral start-up fund of the Second Affiliated Hospital of Nanchang University(B3150)Jiangxi Provincial Natural Science Foundation(20232BAB216042).
文摘Cognitive impairment is a multifactorial and multi-step pathological process that places a heavy burden on patients and the society.Neuroinflammation is one of the main factors leading to cognitive impairment.The inflammasomes are multi-protein complexes that respond to various microorganisms and endogenous danger signals,helping to initiate innate protective responses in inflammatory diseases.NLRP3 inflammasomes produce proinflammatory cytokines(interleukin IL-1βand IL-18)by activating caspase-1.In this review,we comprehensively describe the structure and functions of the NLRP3 inflammasome.We also explore the intrinsic relationship between the NLRP3 inflammasome and cognitive impairment,which involves immune cell activation,cell apoptosis,oxidative stress,mitochondrial autophagy,and neuroinflammation.Finally,we describe NLRP3 inflammasome antagonists as targeted therapies to improve cognitive impairment.
