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Bending Failure Mode and Prediction Method of the Compressive Strain Capacity of A Submarine Pipeline with Dent Defects
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作者 HOU Fu-heng JIA Lu-sheng +3 位作者 CHEN Yan-fei ZHANG Qi ZHONG Rong-feng WANG Chun-sha 《China Ocean Engineering》 SCIE EI CSCD 2024年第4期636-647,共12页
A dent is a common type of defects for submarine pipeline.For submarine pipelines,high hydrostatic pressure and internal pressure are the main loads.Once pipelines bend due to complex subsea conditions,the compression... A dent is a common type of defects for submarine pipeline.For submarine pipelines,high hydrostatic pressure and internal pressure are the main loads.Once pipelines bend due to complex subsea conditions,the compression strain capacity may be exceeded.Research into the local buckling failure and accurate prediction of the compressive strain capacity are important.A finite element model of a pipeline with a dent is established.Local buckling failure under a bending moment is investigated,and the compressive strain capacity is calculated.The effects of different parameters on pipeline local buckling are analyzed.The results show that the dent depth,external pressure and internal pressure lead to different local buckling failure modes of the pipeline.A higher internal pressure indicates a larger compressive strain capacity,and the opposite is true for external pressure.When the ratio of external pressure to collapse pressure of intact pipeline is greater than 0.1,the deeper the dent,the greater the compressive strain capacity of the pipeline.And as the ratio is less than 0.1,the opposite is true.On the basis of these results,a regression equation for predicting the compressive strain capacity of a dented submarine pipeline is proposed,which can be referred to during the integrity assessment of a submarine pipeline. 展开更多
关键词 submarine pipeline dent defect bending load local buckling compressive strain capacity
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Heterointerface Engineering-Induced Oxygen Defects for the Manganese Dissolution Inhibition in Aqueous Zinc Ion Batteries 被引量:1
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作者 Wentao Qu Yong Cai +1 位作者 Baohui Chen Ming Zhang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第3期112-122,共11页
Manganese-based material is a prospective cathode material for aqueous zinc ion batteries(ZIBs)by virtue of its high theoretical capacity,high operating voltage,and low price.However,the manganese dissolution during t... Manganese-based material is a prospective cathode material for aqueous zinc ion batteries(ZIBs)by virtue of its high theoretical capacity,high operating voltage,and low price.However,the manganese dissolution during the electrochemical reaction causes its electrochemical cycling stability to be undesirable.In this work,heterointerface engineering-induced oxygen defects are introduced into heterostructure MnO_(2)(δa-MnO_(2))by in situ electrochemical activation to inhibit manganese dissolution for aqueous zinc ion batteries.Meanwhile,the heterointerface between the disordered amorphous and the crystalline MnO_(2)ofδa-MnO_(2)is decisive for the formation of oxygen defects.And the experimental results indicate that the manganese dissolution ofδa-MnO_(2)is considerably inhibited during the charge/discharge cycle.Theoretical analysis indicates that the oxygen defect regulates the electronic and band structure and the Mn-O bonding state of the electrode material,thereby promoting electron transport kinetics as well as inhibiting Mn dissolution.Consequently,the capacity ofδa-MnO_(2)does not degrade after 100 cycles at a current density of 0.5 Ag^(-1)and also 91%capacity retention after 500cycles at 1 Ag^(-1).This study provides a promising insight into the development of high-performance manganese-based cathode materials through a facile and low-cost strategy. 展开更多
关键词 electrochemical activation HETEROINTERFACE manganese dissolution inhibition oxygen defects zinc ion batteries
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High quality repair of osteochondral defects in rats using the extracellular matrix of antler stem cells 被引量:1
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作者 Yu-Su Wang Wen-Hui Chu +4 位作者 Jing-Jie Zhai Wen-Ying Wang Zhong-Mei He Quan-Min Zhao Chun-Yi Li 《World Journal of Stem Cells》 SCIE 2024年第2期176-190,共15页
BACKGROUND Cartilage defects are some of the most common causes of arthritis.Cartilage lesions caused by inflammation,trauma or degenerative disease normally result in osteochondral defects.Previous studies have shown... BACKGROUND Cartilage defects are some of the most common causes of arthritis.Cartilage lesions caused by inflammation,trauma or degenerative disease normally result in osteochondral defects.Previous studies have shown that decellularized extracellular matrix(ECM)derived from autologous,allogenic,or xenogeneic mesenchymal stromal cells(MSCs)can effectively restore osteochondral integrity.AIM To determine whether the decellularized ECM of antler reserve mesenchymal cells(RMCs),a xenogeneic material from antler stem cells,is superior to the currently available treatments for osteochondral defects.METHODS We isolated the RMCs from a 60-d-old sika deer antler and cultured them in vitro to 70%confluence;50 mg/mL L-ascorbic acid was then added to the medium to stimulate ECM deposition.Decellularized sheets of adipocyte-derived MSCs(aMSCs)and antlerogenic periosteal cells(another type of antler stem cells)were used as the controls.Three weeks after ascorbic acid stimulation,the ECM sheets were harvested and applied to the osteochondral defects in rat knee joints.RESULTS The defects were successfully repaired by applying the ECM-sheets.The highest quality of repair was achieved in the RMC-ECM group both in vitro(including cell attachment and proliferation),and in vivo(including the simultaneous regeneration of well-vascularized subchondral bone and avascular articular hyaline cartilage integrated with surrounding native tissues).Notably,the antler-stem-cell-derived ECM(xenogeneic)performed better than the aMSC-ECM(allogenic),while the ECM of the active antler stem cells was superior to that of the quiescent antler stem cells.CONCLUSION Decellularized xenogeneic ECM derived from the antler stem cell,particularly the active form(RMC-ECM),can achieve high quality repair/reconstruction of osteochondral defects,suggesting that selection of decellularized ECM for such repair should be focused more on bioactivity rather than kinship. 展开更多
关键词 Osteochondral defect repair Mesenchymal stem cells Extracellular matrix DECELLULARIZATION Antler stem cells Reserve mesenchymal cells Xenogeneic
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Built defects of homogeneous junction to enhance the lithium storage capacity of niobium pentoxide materials
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作者 Huibin Ding Yang Luo +5 位作者 Zihan Song Cong Chen Kai Feng Xiaofei Yang Hongzhang Zhang Xianfeng Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期730-737,共8页
Niobium pentoxide(Nb_(2)O_(5))is deemed one of the promising anode materials for lithium-ion batteries(LIBs)for its outstanding intrinsic fast Li-(de)intercalation kinetics.The specific capacity,however,is still limit... Niobium pentoxide(Nb_(2)O_(5))is deemed one of the promising anode materials for lithium-ion batteries(LIBs)for its outstanding intrinsic fast Li-(de)intercalation kinetics.The specific capacity,however,is still limited,because the(de)intercalation of excessive Li-ions brings the undesired stress to damage Nb_(2)O_(5) crystals.To increase the capacity of Nb_(2)O_(5) and alleviate the lattice distortion caused by stress,numerous homogeneous H-and M-phases junction interfaces were proposed to produce coercive stress within theNb_(2)O_(5)crystals.Such interfaces bring about rich oxygen vacancies with structural shrinkage tendency,which pre-generate coercive stress to resist the expansion stress caused by excessive Li-ions intercalation.Therefore,the synthesized Nb_(2)O_(5) achieves the highest lithium storage capacity of 315 mA h g−1 to date,and exhibits high-rate performance(118 mA h g^(-1) at 20 C)as well as excellent cycling stability(138 mA h g^(-1) at 10 C after 600 cycles). 展开更多
关键词 Niobiumpent oxide Homojunction polycrystalline defects Oxygen vacancy
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Visualizing extended defects at the atomic level in a Bi_(2)Sr_(2)CaCu_(2)O8_(+σ) superconducting wire
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作者 Kejun Hu Shuai Wang +3 位作者 Boyu Li Ying Liu Binghui Ge Dongsheng Song 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期43-47,共5页
The microstructure significantly influences the superconducting properties.Herein,the defect structures and atomic arrangements in high-temperature Bi_(2)Sr_(2)CaCu_(2)O8_(+σ) superconducting wire are directly charac... The microstructure significantly influences the superconducting properties.Herein,the defect structures and atomic arrangements in high-temperature Bi_(2)Sr_(2)CaCu_(2)O8_(+σ) superconducting wire are directly characterized via stateof-the-art scanning transmission electron microscopy.Interstitial oxygen atoms are observed in both the charge reservoir layers and grain boundaries in the doped superconductor.Inclusion phases with varied numbers of CuO_(2) layers are found,and twist interfaces with different angles are identified.This study provides insights into the structures of Bi-2212 wire and lays the groundwork for guiding the design of microstructures and optimizing the production methods to enhance superconducting performance. 展开更多
关键词 SUPERCONDUCTOR microstructure DEFECT SCANNING transmission ELECTRON MICROSCOPY
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Theoretical Design of Defects as a Driving Force for Ion Transport in Li_(3)OBr Solid Electrolyte
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作者 Xingyun Luo Yanlu Li Xian Zhao 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第3期143-153,共11页
Due to ever-increasing concerns about safety issues in using Li ionic batteries,solid electrolytes have extensively explored.The Li-rich antiperovskite Li_(3)OBr has been considered as a promising solid electrolyte ca... Due to ever-increasing concerns about safety issues in using Li ionic batteries,solid electrolytes have extensively explored.The Li-rich antiperovskite Li_(3)OBr has been considered as a promising solid electrolyte candidate,but it still suffers challenges to achieve a high ionic conductivity owing to the high intrinsic symmetry of the crystal lattice.Herein,we presented a design strategy that introduces various point defects and grain boundaries to break the high lattice symmetry of Li_(3)OBr crystal,and their effect and microscopic mechanism of promoting the migration of Li-ion were explored theoretically.It has been found that Li_(i)are the dominant defects responsible for the fast Li-ion diffusion in bulk Li_(3)OBr and its surface,but they are easily trapped by the grain boundaries,leading to the annihilating of the Frenkel defect pair V'_(Li)+Li_(i),and thus limits the V'_(Li)diffusion at the grain boundaries.The V_(Br)defect near the grain boundaries can effectively drive V'_(Li)across the grain boundary,thereby converting the carrier of Li^(+)migration from Li,in the bulk and surface to V'_(Li)at the grain boundary,and thus improving the ionic conductivity in the whole Li_(3)OBr crystal.This work provides a comprehensive insight into the Li^(+)transport and conduction mechanism in the Li_(3)OBr electrolyte.It opens a new way of improving the conductivity for all-solid-state Li electrolyte material through the defect design. 展开更多
关键词 defects density functional theory ionic migration solid electrolyte
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Interfacial modification using the cross-linkable tannic acid for highly-efficient perovskite solar cells with excellent stability
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作者 Xing Gao Lirong Rong +6 位作者 Fei Wu Yen-Hung Lin Ye Zeng Junhong Tan Rongxing He Cheng Zhong Linna Zhu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第4期236-244,共9页
Although the performance of perovskite solar cells(PSCs)has been dramatically increased in recent years,stability is still the main obstacle preventing the PSCs from being commercial.PSC device instability can be caus... Although the performance of perovskite solar cells(PSCs)has been dramatically increased in recent years,stability is still the main obstacle preventing the PSCs from being commercial.PSC device instability can be caused by a variety of reasons,including ions diffusion,surface and grain boundary defects,etc.In this work,the cross-linkable tannic acid(TA)is introduced to modify perovskite film through post-treatment method.The numerous organic functional groups(–OH and C=O)in TA can interact with the uncoordinated Pb^(2+)and I^(-)ions in perovskite,thus passivating defects and inhibiting ions diffusion.In addition,the formed TA network can absorb a small amount of the residual moisture inside the device to protect the perovskite layer.Furthermore,TA modification regulates the energy level of perovskite,and reduces interfacial charge recombination.Ultimately,following TA treatment,the device efficiency is increased significantly from 21.31%to 23.11%,with a decreased hysteresis effect.Notably,the treated device shows excellent air,thermal,and operational stability.In light of this,the readily available,inexpensive TA has the potential to operate as a multipurpose interfacial modifier to increase device efficiency while also enhancing device stability. 展开更多
关键词 Tannic acid Defect passivation lons diffusion HYDROPHILIC STABILITY Perovskite solar cells
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Retinal nerve fiber layer defects and chronic kidney disease:the Kailuan Eye Study
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作者 Qian-Qian Wan Jin-Qiong Zhou +9 位作者 Li-Jian Fang Ya-Xing Wang Ye-Nan Wang Qian Wang Yan-Ni Yan Xuan Yang Shou-Ling Wu Shuo-Hua Chen Jost B Jonas Wen-Bin Wei 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第9期1696-1706,共11页
AIM:To investigate whether retinal nerve fiber layer defects(RNFLDs)is a potential risk factor for chronic kidney disease(CKD)in Chinese adults.METHODS:The Kailuan Eye Study was a populationbased study that included 1... AIM:To investigate whether retinal nerve fiber layer defects(RNFLDs)is a potential risk factor for chronic kidney disease(CKD)in Chinese adults.METHODS:The Kailuan Eye Study was a populationbased study that included 14440 participants.All participants underwent detailed assessments,RNFLDs were diagnosed using color fundus photographs.RESULTS:Overall,12507 participants[8533 males(68.23%)]had complete systemic examination data and at least one evaluable fundus photograph.RNFLDs were found in 621 participants[5.0%;95%confidence interval(CI):4.6%-5.34%],and 70 cases of multiple RNFLDs were found(11.27%).After adjusting multiple factors,RNFLDs was significantly associated with CKD severity,the ORs of CKD stage 3,stage 4 and stage 5 were 1.698,4.167,and 9.512,respectively.Multiple RNFLDs were also associated with CKD severity after adjusting multiple factors,the ORs of CKD stage 3 and stage 5 were 4.465 and 11.833 respectively.Furthermore,2294 participants had CKD(18.34%,95%CI:17.68%-18.99%).After adjusting for other factors,CKD presence was significantly correlated with the presence of RNFLDs.CONCLUSION:The strongest risk factors for RNFLDs are CKD and hypertension.Conversely,RNFLDs can be an ocular feature in patients with CKD.Fundoscopy can help detect systemic diseases,and assessment for RNFLDs should be considered in CKD patients. 展开更多
关键词 chronic kidney disease retinal nerve fiber layer defects Kailuan Eye Study fundus examination
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Association of Congenital Heart Defects (CHD) with Factors Related to Maternal Health and Pregnancy in Newborns in Puerto Rico
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作者 Yamixa Delgado Caliani Gaytan +3 位作者 Naydi Perez Eric Miranda Bryan Colón Morales Mónica Santos 《Congenital Heart Disease》 SCIE 2024年第1期19-31,共13页
Background:Given the pervasive issues of obesity and diabetes both in Puerto Rico and the broader United States,there is a compelling need to investigate the intricate interplay among body mass index(BMI),pregesta-tio... Background:Given the pervasive issues of obesity and diabetes both in Puerto Rico and the broader United States,there is a compelling need to investigate the intricate interplay among body mass index(BMI),pregesta-tional,and gestational maternal diabetes,and their potential impact on the occurrence of congenital heart defects(CHD)during neonatal development.Methods:Using the comprehensive System of Vigilance and Surveillance of Congenital Defects in Puerto Rico,we conducted a focused analysis on neonates diagnosed with CHD between 2016 and 2020.Our assessment encompassed a range of variables,including maternal age,gestational age,BMI,pregestational diabetes,gestational diabetes,hypertension,history of abortion,and presence of preeclampsia.Results:A cohort of 673 patients was included in our study.The average maternal age was 26 years,within a range of 22 to 32 years.The mean gestational age measured 39 weeks,with a median span of 38 to 39 weeks.Of the 673 patients,274(41%)mothers gave birth to neonates diagnosed with CHD.Within this group,22 cases were linked to pre-gestational diabetes,while 202 were not;20 instances were associated with gestational diabetes,compared to 200 without;and 148 cases exhibited an overweight or obese BMI,whereas 126 displayed a normal BMI.Conclusion:We identified a statistically significant correlation between pre-gestational diabetes mellitus and the occurrence of CHD.However,our analysis did not show a statistically significant association between maternal BMI and the likelihood of CHD.These results may aid in developing effective strategies to prevent and manage CHD in neonates. 展开更多
关键词 Congenital heart defects(CHD) obesisty maternal health DIABETES body mass index(BMI)
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Effect of Vacancy Defects on the Properties of CoS_(2) and FeS_(2)
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作者 冯中营 ZHANG Jianmin +3 位作者 WANG Xiaowei YANG Wenjin JING Yinlan YANG Yan 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第3期627-638,共12页
In order to explore the effect of vacancy defects on the structural,electronic,magnetic and optical properties of CoS_(2) and FeS_(2),first-principles calculation method was used to investigate the alloys.The calculat... In order to explore the effect of vacancy defects on the structural,electronic,magnetic and optical properties of CoS_(2) and FeS_(2),first-principles calculation method was used to investigate the alloys.The calculated results of materials without vacancy are consistent with those reported in the literatures,while the results of materials with vacancy defect were different from those of literatures due to the difference vacancy concentration.The Co vacancy defect hardly changes the half-metallic characteristic of CoS_(2).The Fe vacancy defect changes FeS_(2) from semiconductor to half-metal,and the bottom of the spin-down conduction band changes from the p orbital state of S to the d(t_(2g))orbital state of Fe,while the top of the valence band remains the d orbital d(eg)state of Fe.The half-metallic Co vacancy defects of CoS_(2) and Fe vacancy defects of FeS_(2) are expected to be used in spintronic devices.S vacancy defects make both CoS_(2) and FeS_(2) metallic.Both the Co and S vacancy defects lead to the decrease of the magnetic moment of CoS_(2),while both the Fe and S vacancy defects lead to the obvious magnetic property of FeS_(2).Vacancy defects enhance the absorption coefficient of infrared band and long band of visible light obviously,and produce obvious red shift phenomenon,which is expected to be used in photoelectric devices. 展开更多
关键词 cobalt disulfide iron disulfide vacancy defect fist principles
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Simulation on dynamic characteristics of TC4 cutting with crack defects
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作者 SHI Lichen WANG Jian +1 位作者 DOU Weitao YUAN Jiageng 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2024年第3期387-396,共10页
Titanium alloys play an important role in aerospace and other fields.However,after precision forging and cold rolling process,some defects will appear on the subsurface of titanium alloy bars,thus reducing the surface... Titanium alloys play an important role in aerospace and other fields.However,after precision forging and cold rolling process,some defects will appear on the subsurface of titanium alloy bars,thus reducing the surface quality and precision of turning process.This study aimed at exploring the effect of crack defects on TC4 cutting.Firstly,the finite element cutting simulation model of TC4 material with crack defects was established in ABAQUS.Then,the cutting parameters such as cutting force,stress concentration,chip morphology,residual stress were obtained by changing the variables such as the size and height of crack defects.Finally,the turning experiment was carried out on centerless lathe.The results show that the cutting force changes abruptly when the defect position is located on the cutting path,the maximal stress occurs at the tip of the defect,and the mutation of stress value is more serious with the increase of defect size;the buckling deformation of chip morphology occurs and becomes less serious with the increase of the distance between the defect position and the workpiece surface;the surface residual stress near the defect is related to the stress when the tool is close to the defect,the larger defect size and the closer to the machined surface,the greater the residual stress.Therefore,under certain processing conditions,the TC4 material should avoid large size defects or increase the distance between defects and the machined surface,so as to obtain better and stable surface quality. 展开更多
关键词 crack defect TC4 ABAQUS centerless lathe
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Analysis of spot defects on the surface of a cold-rolled Fe-36%Ni alloy strip
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作者 TIAN Yuxin WANG Yu ZHU Yincun 《Baosteel Technical Research》 CAS 2024年第2期27-31,共5页
Many spot defects were found on the surface of a cold-rolled Fe-36%Ni alloy strip produced in a factory,which seriously affected the surface quality of the product.Through metallographic microscopy and scanning electr... Many spot defects were found on the surface of a cold-rolled Fe-36%Ni alloy strip produced in a factory,which seriously affected the surface quality of the product.Through metallographic microscopy and scanning electron microscopy analyses,it was found that the spot defects were caused by the residual oxide layer on the surface of the cold-rolled Fe-36%Ni alloy strip after hydrogen annealing.By properly increasing the grinding amount of the blank before cold rolling to remove the oxide layer,the spot defects on the surface of the cold-rolled strip were effectively eliminated,and the surface quality of the product was ensured. 展开更多
关键词 Fe-36%Ni alloy cold-rolled strip spot defect
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An Analysis of Specific Categories of Birth Defects and Developmental Disabilities for Children of Participants of the Air Force Health Study
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作者 George J. Knafl 《Open Journal of Epidemiology》 2024年第2期312-330,共19页
Background: The Air Force Health Study collected reproductive outcomes for live-born children of male Air Force veterans of the Vietnam War. Methods: Dioxin values for participants were obtained from blood samples. An... Background: The Air Force Health Study collected reproductive outcomes for live-born children of male Air Force veterans of the Vietnam War. Methods: Dioxin values for participants were obtained from blood samples. Analyses were conducted of occurrence of 16 specific categories of birth defects and developmental disabilities. Children were categorized as conceived before and after the start of participants’ Vietnam War service. Children conceived before the start of Vietnam War service were treated as being conceived when their fathers had unquantifiable dioxin values. Children conceived after the start of Vietnam War service for participants with missing dioxin values were excluded from primary analyses, but were used to assess the impact of their exclusion on conclusions. Correlation between values for specific categories for multiple children fathered by the same participant was accounted for. The dose-response relationship was treated as a step function increasing for dioxin values larger than adaptively identified individual thresholds changing with the specific category. Results: For 15 of 16 specific categories, the probability of occurrence increased substantially for a sufficiently high dioxin level above identified thresholds. Exclusion of children due to missing dioxin likely did not affect these results. Conclusions: Results supported the conclusion of substantial adverse effects on a wide variety of specific categories of birth defects and developmental disabilities due to sufficiently high exposures to dioxin, a toxic contaminant of Agent Orange used for herbicide spraying in the Vietnam War. Results may hold more generally, but might also have been affected by a variety of limitations. 展开更多
关键词 Agent Orange Air Force Health Study Birth defects Developmental Disabilities DIOXIN Dose-Response Relationship Vietnam War
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Clinical Efficacy of GBR Technique Combined with Temporary Bridgework-Guided Gingival Contouring in Treating Upper Anterior Tooth Loss with Labial Bone Defects
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作者 Yu Ma Jirui Ma 《Journal of Clinical and Nursing Research》 2024年第6期171-176,共6页
Objective:To investigate the clinical effect of the guided bone regeneration(GBR)technique combined with temporary bridgework-guided gingival contouring in treating upper anterior tooth loss with labial bone defects.M... Objective:To investigate the clinical effect of the guided bone regeneration(GBR)technique combined with temporary bridgework-guided gingival contouring in treating upper anterior tooth loss with labial bone defects.Methods:From July 2023 to April 2024,80 patients with upper anterior tooth loss and labial bone defects were admitted to the hospital and selected as evaluation samples.They were divided into an observation group(n=40)and a control group(n=40)using a numerical table lottery scheme.The control group received treatment with the GBR technique,while the observation group received treatment with the GBR technique combined with temporary bridges to guide gingival contouring.The two groups were compared in terms of clinical red aesthetic scores(PES),labial alveolar bone density,labial bone wall thickness,gingival papillae,gingival margin levels,and patient satisfaction.Results:The PES scores of patients in the observation group were higher than those in the control group after surgery(P<0.05).The bone density of the labial alveolar bone and the thickness of the labial bone wall in the observation group were higher than those in the control group.The levels of gingival papillae and gingival margins were lower in the observation group after surgery(P<0.05).Additionally,patient satisfaction in the observation group was higher than in the control group(P<0.05).Conclusion:The GBR technique combined with temporary bridge-guided gingival contouring for treating upper anterior tooth loss with labial bone defects can improve the aesthetic effect of gingival soft tissue,increase alveolar bone density and the thickness of the labial bone wall,and enhance patient satisfaction.This approach is suitable for widespread application in healthcare institutions. 展开更多
关键词 Upper anterior teeth loss Labial bone defects Guided bone regeneration(GBR)technique Temporary bridgework-guided gingival contouring
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RuO_(2)-PdO nanowire networks with rich interfaces and defects supported on carbon toward the efficient alkaline hydrogen oxidation reaction
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作者 Yuanyuan Cong Fanchao Meng +5 位作者 Haibin Wang Di Dou Qiuping Zhao Chunlei Li Ningshuang Zhang Junying Tian 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第8期255-263,I0008,共10页
Interfacial engineering is a promising approach for enhancing electrochemical performance,but rich and efficient interfacial active sites remain a challenge in fabrication.Herein,RuO_(2)-PdO heterostructure nanowire n... Interfacial engineering is a promising approach for enhancing electrochemical performance,but rich and efficient interfacial active sites remain a challenge in fabrication.Herein,RuO_(2)-PdO heterostructure nanowire networks(NWs) with rich interfaces and defects supported on carbon(RuO_(2)-PdO NWs/C) for alkaline hydrogen oxidation reaction(HOR) was formed by a seed induction-oriented attachment-thermal treatment method for the first time.As expected,the RuO_(2)-PdO NWs/C(72.8% Ru atomic content in metal) exhibits an excellent activity in alkaline HOR with a mass specific exchange current density(jo,m) of 1061 A gRuPd-1,which is 3.1 times of commercial Pt/C and better than most of the reported nonPt noble metal HOR electrocatalysts.Even at the high potential(~0.5 V vs.RHE) or the presence of CO(5 vol%),the RuO_(2)-PdO NWs/C still effectively catalyzes the alkaline HOR.Structure/electrochemical analysis and theoretical calculations reveal that the interfaces between RuO_(2) and PdO act as the active sites.The electronic interactions between the two species and the rich defects for the interfacial active sites weaken the adsorption of Had,also strengthen the adsorption of OHad,and accelerate the alkaline HOR process.Moreover,OHadon RuO_(2) can spillover to the interfaces,keeping the RuO_(2)-PdO NWs/C with the stable current density at higher potential and high resistance to CO poisoning. 展开更多
关键词 Hydrogen oxidation reaction HETEROSTRUCTURE Nanowire networks defects Interfacial active sites
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Propagation Characteristics of Ultrasonic Guided Waves in Grouted Rockbolt Systems with Bond Defects under Different Confining Conditions
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作者 Shuisheng Yu Jin Chen +2 位作者 Yawei Wang Honghao Yang Shucan Lu 《Journal of Modern Physics》 CAS 2023年第5期722-740,共19页
A rockbolt acting in the rock mass is subjected to the combined action of the pull-out load and confining pressure, and the bond quality of the rockbolt directly affects the stability of the roadway and cavern. Theref... A rockbolt acting in the rock mass is subjected to the combined action of the pull-out load and confining pressure, and the bond quality of the rockbolt directly affects the stability of the roadway and cavern. Therefore, in this study, confining pressure and pull-out load are applied to grouted rockbolt systems with bond defects by a numerical simulation method, and the rockbolt is detected by ultrasonic guided waves to study the propagation law of ultrasonic guided waves in defective rockbolt systems and the bond quality of rockbolts under the combined action of pull-out load and confining pressure. The numerical simulation results show that the length and location of bond defects can be detected by ultrasonic guided waves under the combined action of pull-out load and confining pressure. Under no pull-out load, with increasing confining pressure, the low-frequency part of the guided wave frequency in the rockbolt increases, the high-frequency part decreases, the weakening effect of the confining pressure on the guided wave propagation law increases, and the bond quality of the rockbolt increases. The existence of defects cannot change the strengthening effect of the confining pressure on the guided wave propagation law under the same pull-out load or the weakening effect of the pull-out load on the guided wave propagation law under the same confining pressure. 展开更多
关键词 Grouted Rockbolt systems Bond Defect Pull-Out Load Confining Pressure Ultrasonic Guided Wave
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Construction of a three-dimensional bionic nerve conduit containing two neurotrophic factors with separate delivery systems for the repair of sciatic nerve defects 被引量:3
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作者 Zhiyue Li Qun Zhao +2 位作者 Ran Bi Yong Zhuang Siyin Feng 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第13期988-994,共7页
Previous studies of nerve conduits have investigated numerous properties, such as conduit luminal structure and neurotrophic factor incorporation, for the regeneration of nerve defects. The present study used a poly(... Previous studies of nerve conduits have investigated numerous properties, such as conduit luminal structure and neurotrophic factor incorporation, for the regeneration of nerve defects. The present study used a poly(lactic-co-glycolic acid) (PLGA) copolymer to construct a three-dimensional (3D) bionic nerve conduit, with two channels and multiple microtubule lumens, and incorporating two neurotrophic factors, each with their own delivery system, as a novel environment for peripheral nerve regeneration. The efficacy of this conduit in repairing a 1.5 cm sciatic nerve defect was compared with PLGA-alone and PLGA-microfilament conduits, and autologous nerve transplantation. Results showed that compared with the other groups, the 3D bionic nerve conduit had the fastest nerve conduction velocity, largest electromyogram amplitude, and shortest electromyogram latency. In addition, the nerve fiber density, myelin sheath thickness and axon diameter were significantly increased, and the recovery rate of the triceps surae muscle wet weight was lowest. These findings suggest that 3D bionic nerve conduits can provide a suitable microenvironment for peripheral nerve regeneration to efficiently repair sciatic nerve defects. p 展开更多
关键词 oly(lactic-co-glycolic acid) sciatic nerve defect nerve conduit BIONICS nerve tissue engineering neural regeneration
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The Role of Transesophageal Echocardiography for Transcatheter Closure of Atrial Septal Defects with the Amplatzer Septal Occluder 被引量:1
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作者 许迪 孔祥清 +3 位作者 杨荣 盛燕辉 曹克将 陆凤翔 《Journal of Nanjing Medical University》 2003年第3期110-115,共6页
Objective: To evaluate of the role of transesophageal echocardiography (TEE)in percutaneous closure of atrial septal defects (ASD) with the Amplatzer septal occluder. Methods:Sixty- two patients (10 to 55 years of age... Objective: To evaluate of the role of transesophageal echocardiography (TEE)in percutaneous closure of atrial septal defects (ASD) with the Amplatzer septal occluder. Methods:Sixty- two patients (10 to 55 years of age) were selected for percutaneous closure of ASD bytrans-esophageal echocardiography, which was also used to monitor the procedure, to select theappropriate size of the Amplatzer device, to verify its position, and to access the immediateresults of the procedure. During the follow-up, transthoracic echocardiography (TTE) or TEE was usedto evaluate the presence and magnitude of residual shunt (RS), device position, and right cardiacchamber diameters. Results: The mean ASD diameter by TTE ([19. 1 +- 5. 8] mm) was significantlysmaller (P< 0. 001) than the stretched diameter of the ASD (25. 1 +- 6. 4) mm. There are nosignificant differences between the TEE -measured value (23. 5+_6. 2) mm and the stretched diameterof the ASD (P > 0. 05). Due to proper patient selection all procedures were successful. There wasimmediate and complete closure in 61/62 patients, only one patients had trivial residual shunt.Follow- up was performed using TTE or TEE right after operation, 1 d, 1 month, 3 months, 6 monthsand yearly thereafter. Ail, patients remain asymptomatic without any clinical or technical problems.Conclusion: With the aid of TEE, percutaneous closure of ASD can be performed successfully, safely,and effectively. 展开更多
关键词 transesophageal echocardiography atrial septal defects amplatzer septaloccluder
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Genetic Analysis of Variants of the MYH6 Gene Promoter in Congenital Atrial Septal Defects 被引量:1
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作者 Ji-Yang Zuo Huan-Xin Chen +2 位作者 Zhi-Gang Liu Qin Yang Guo-Wei He 《Congenital Heart Disease》 SCIE 2023年第1期7-21,共15页
Background:Atrial septal defect(ASD)is one of the common congenital heart diseases.The MYH6 gene has a critical role in cardiac development but the role of MYH6 promoter variants in patients with ASD has not been expl... Background:Atrial septal defect(ASD)is one of the common congenital heart diseases.The MYH6 gene has a critical role in cardiac development but the role of MYH6 promoter variants in patients with ASD has not been explored.Methods:In 613 subjects including 320 ASD patients,we investigated the MYH6 gene promoter variants and verified the effect on gene expression by using cellular functional experiments and bioinformatics analysis.Results:Eleven variants were identified in the MYH6 gene promoter,of which four variants were found only in ASD patients,and two variants(g.3434G>C and g.4524C>T)were identified for the first time.Cellular functional experiments indicated that all four variants reduced the transcriptional activity of the MYH6 gene promoter(p<0.05).Subsequent analysis through the JASPAR(A database of transcription factor binding profiles)suggests that these variants may alter transcription factor binding sites,which may in turn lead to changes in myocardin subunit expression and ASD formation.Conclusions:Our study for the first time focuses on variants in the promoter region of the MYH6 gene in Chinese patients with ASD and the discovered variants have functional significance.The study provides new insights in the role of the MYH6 gene promoter region to better understand the genetic basis of ASD formation and facilitates clinical diagnosis. 展开更多
关键词 Atrial septal defect MYH6 GENETIC VARIANTS congenital heart disease
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Unravel the Charge-Carrier Dynamics in Simple Dimethyl Oxalate-Treated Perovskite Solar Cells with Efficiency Exceeding 22% 被引量:1
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作者 Rongjun Zhao Tai Wu +2 位作者 Rongshan Zhuang Yong Hua Yude Wang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第5期219-227,共9页
Understanding the effect of additive on the interfacial charge-carrier transfer dynamics is very crucial to obtaining highly efficient perovskite solar cells(PSCs).Herein,we designed a simple additive,dimethyl oxalate... Understanding the effect of additive on the interfacial charge-carrier transfer dynamics is very crucial to obtaining highly efficient perovskite solar cells(PSCs).Herein,we designed a simple additive,dimethyl oxalate(DO),functioning as an effective defect passivator of perovskite grain boundaries via the coordination interaction between the carbonyl(C=O)and the exposed Pb^(2+).The modification with DO produces pinhole-free and compact perovskite films,enhancing the transportation capability of carriers.As a consequence,the DO-treated PSCs exhibited a power conversion efficiency(PCE)of 22.19%,which is significantly higher than that of the control device without additive(19.58%).More importantly,detailed transient absorption characterization reveals that the use of additive can decrease the hot-carrier cooling dynamics,improve the carrier transfer,and eliminate nonradiative recombination in PSCs.This present work provides a profound understanding the additives effect on the carrier dynamics in PSCs toward the Shockley-Queisser limit. 展开更多
关键词 additive engineering carrier dynamics defect passivation Perovskite solar cell
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