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Dynamic analysis of buried pipeline with and without barrier system subjected to underground detonation
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作者 Chaidul Haque Chaudhuri Deepankar Choudhury 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第11期95-105,共11页
Failure of pipe networks due to blast loads resulting from terrorist attacks or construction facilities, may cause economic loss, environmental pollution, source of firing or even it may lead to a disaster. The presen... Failure of pipe networks due to blast loads resulting from terrorist attacks or construction facilities, may cause economic loss, environmental pollution, source of firing or even it may lead to a disaster. The present work develops a closed-form solution of buried pipe with barrier system subjected to subsurface detonation. The solution is derived based on the concept of double-beam system. Euler Bernoulli's beams are used to simulate the buried pipe and the barrier system. Soil is idealized as viscoelastic foundation along with shear interaction between discrete Winkler springs(advanced soil model). The finite SineFourier transform is employed to solve the coupled partial differential equations. The solution is validated with past studies. A parametric study is conducted to investigate the influence of TNT charge weight, pipe material, damping ratio and TNT offset on the response of buried pipe with and without barrier system. Further a statistical analysis is carried out to get the significant soil and pipe input parameters. It is perceived that peak pipe displacements for both the cases(with and without barrier) are increases with increasing the weight of TNT charge and decreases with increasing the damping ratio and TNT offset. The deformation of pipe also varies with pipe material. Pipe safety against blast loads can be ensured by providing suitable barrier layer. The present study can be utilized in preliminary design stage as an alternative to expensive numerical analysis or field study. 展开更多
关键词 Buried pipeline Subsurface detonation Analytical solution Viscoelastic foundation Protective barrier
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Swelling ability and behaviour of bentonite-based materials for deep repository engineered barrier systems:Influence of physical,chemical and thermal factors 被引量:2
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作者 Mohammed Alzamel Mamadou Fall Sada Haruna 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2022年第3期689-702,共14页
Compacted bentonite-sand(B/S)mixtures have been used as a barrier material in engineered barrier systems(EBSs)of deep geological repositories(DGR)to store nuclear wastes.This study investigates the individual and comb... Compacted bentonite-sand(B/S)mixtures have been used as a barrier material in engineered barrier systems(EBSs)of deep geological repositories(DGR)to store nuclear wastes.This study investigates the individual and combined effects of different chemical compositions of deep groundwaters(chemical factor)at potential repository sites in Canada(the Trenton and Guelph regions in Ontario),heat generated in DGRs(thermal factor),dry densities and mass ratios of bentonite and sand mixtures(physical factors)on the swelling behavior and ability of bentonite-based materials.In this study,swelling tests are conducted on B/S mixtures with different B/S mix ratios(20/80 to 70/30),compacted at different dry densities(ρd=1.6-2 g/cm^(3)),saturated with different types of water(distilled water and simulated deep groundwater of Trenton and Guelph)and exposed to different temperatures(20℃-80℃).Moreover,scanning electron microscopy(SEM)analyses,mercury intrusion porosimetry(MIP)tests and X-ray diffractometry(XRD)analyses are carried out to evaluate the morphological,microstructural and mineralogical characteristics of the B/S mixtures.The test results indicate that the swelling potential of the B/S mixtures is significantly affected by these physical and chemical factors as well as the combined effects of the chemical and thermal factors.A significant decrease in the swelling capacity is observed when the B/S materials are exposed to the aforementioned groundwaters.A large decrease in the swelling capacity is observed for higher bentonite content in the mixtures.Moreover,higher temperatures intensify the chemically-induced reduction of the swelling capacity of the B/S barrier materials.This decrease in the swelling capacity is caused by the chemical and/or microstructural changes of the materials.The results from this research will help engineers to design and build EBSs for DGRs with similar groundwater and thermal conditions. 展开更多
关键词 Deep geological repository Engineered barrier Bentonite-sand materials Nuclear waste Swelling capacity Swelling strain
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Influence of Iron Supplementation on DMT1(IRE)-induced Transport of Lead by Brain Barrier Systems in vivo 被引量:1
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作者 AN Dai Zhi AI Jun Tao +4 位作者 FANG Hong Juan SUN Ru Bao SHI Yun WANG Li Li WANG Qiang 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2015年第9期651-659,共9页
Objective To investigate the potential involvement of DMT1(IRE) protein in the brain vascular system in vivo during Pb exposure. Methods Three groups of male Sprague-Dawley rats were exposed to Pb in drinking water,... Objective To investigate the potential involvement of DMT1(IRE) protein in the brain vascular system in vivo during Pb exposure. Methods Three groups of male Sprague-Dawley rats were exposed to Pb in drinking water, among which two groups were concurrently administered by oral gavage once every other day as the low and high Fe treatment group, respectively, for 6 weeks. At the same time, the group only supplied with high Fe was also set as a reference. The animals were decapitated, then brain capillary-rich fraction was isolate from cerebral cortex. Western blot method was used to identify protein expression, and RT-PCR to detect the change of the m RNA. Results Pb exposure significantly increased Pb concentrations in cerebral cortex. Low Fe dose significantly reduced the cortex Pb levels, However, high Fe dose increased the cortex Pb levels. Interestingly, changes of DMT1(IRE) protein in brain capillary-rich fraction were highly related to the Pb level, but those of DMT1(IRE) m RNA were not significantly different. Moreover, the consistent changes in the levels of p-ERK1/2 or IRP1 with the changes in the levels of DMT1(IRE). Conclusion These results suggest that Pb is transported into the brain through DMT1(IRE), and the ERK MAPK pathway is involved in DMT1(IRE)-mediated transport regulation in brain vascular system in vivo. 展开更多
关键词 Lead Iron Blood-brain barrier Divalent metal transporter 1 MAPK pathway
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Establishment of a chicken intestinal organoid culture system to assess deoxynivalenol‑induced damage of the intestinal barrier function
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作者 Tae Hong Kang Sang In Lee 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第3期1119-1130,共12页
Background Deoxynivalenol(DON)is a mycotoxin that has received recognition worldwide because of its ability to cause growth delay,nutrient malabsorption,weight loss,emesis,and a reduction of feed intake in livestock.S... Background Deoxynivalenol(DON)is a mycotoxin that has received recognition worldwide because of its ability to cause growth delay,nutrient malabsorption,weight loss,emesis,and a reduction of feed intake in livestock.Since DON-contaminated feedstuff is absorbed in the gastrointestinal tract,we used chicken organoids to assess the DON-induced dysfunction of the small intestine.Results We established a culture system using chicken organoids and characterized the organoids at passages 1 and 10.We confirmed the mRNA expression levels of various cell markers in the organoids,such as KI67,leucine-rich repeat containing G protein-coupled receptor 5(Lgr5),mucin 2(MUC2),chromogranin A(CHGA),cytokeratin 19(CK19),lysozyme(LYZ),and microtubule-associated doublecortin-like kinase 1(DCLK1),and compared the results to those of the small intestine.Our results showed that the organoids displayed functional similarities in permeability compared to the small intestine.DON damaged the tight junctions of the organoids,which resulted in increased permeability.Conclusions Our organoid culture displayed topological,genetic,and functional similarities with the small intes-tine cells.Based on these similarities,we confirmed that DON causes small intestine dysfunction.Chicken organoids offer a practical model for the research of harmful substances. 展开更多
关键词 barrier function DEOXYNIVALENOL ORGANOIDS
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Recent advances in zwitterionic nanoscale drug delivery systems to overcome biological barriers
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作者 Xumei Ouyang Yu Liu +2 位作者 Ke Zheng Zhiqing Pang Shaojun Peng 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2024年第1期49-68,共20页
Nanoscale drug delivery systems(nDDS)have been employed widely in enhancing the therapeutic efficacy of drugs against diseases with reduced side effects.Although several nDDS have been successfully approved for clinic... Nanoscale drug delivery systems(nDDS)have been employed widely in enhancing the therapeutic efficacy of drugs against diseases with reduced side effects.Although several nDDS have been successfully approved for clinical use up to now,biological barriers between the administration site and the target site hinder the wider clinical adoption of nDDS in disease treatment.Polyethylene glycol(PEG)-modification(or PEGylation)has been regarded as the gold standard for stabilising nDDS in complex biological environment.However,the accelerated blood clearance(ABC)of PEGylated nDDS after repeated injections becomes great challenges for their clinical applications.Zwitterionic polymer,a novel family of antifouling materials,have evolved as an alternative to PEG due to their super-hydrophilicity and biocompatibility.Zwitterionic nDDS could avoid the generation of ABC phenomenon and exhibit longer blood circulation time than the PEGylated analogues.More impressively,zwitterionic nDDS have recently been shown to overcome multiple biological barriers such as nonspecific organ distribution,pressure gradients,impermeable cell membranes and lysosomal degradation without the need of any complex chemical modifications.The realization of overcoming multiple biological barriers by zwitterionic nDDS may simplify the current overly complex design of nDDS,which could facilitate their better clinical translation.Herein,we summarise the recent progress of zwitterionic nDDS at overcoming various biological barriers and analyse their underlyingmechanisms.Finally,prospects and challenges are introduced to guide the rational design of zwitterionic nDDS for disease treatment. 展开更多
关键词 Zwitterionic polymer Nano drug delivery system Biological barrier Targeting delivery Disease treatment
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Practical bipartite consensus for multi-agent systems:A barrier function-based adaptive sliding-mode control approach 被引量:3
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作者 Boda Ning Qing-Long Han Xiaohua Ge 《Journal of Automation and Intelligence》 2023年第1期14-19,共6页
This paper is concerned with bipartite consensus tracking for multi-agent systems with unknown disturbances.A barrier function-based adaptive sliding-mode control(SMC)approach is proposed such that the bipartite stead... This paper is concerned with bipartite consensus tracking for multi-agent systems with unknown disturbances.A barrier function-based adaptive sliding-mode control(SMC)approach is proposed such that the bipartite steady-state error is converged to a predefined region of zero in finite time.Specifically,based on an error auxiliary taking neighboring antagonistic interactions into account,an SMC law is designed with an adaptive gain.The gain can switch to a positive semi-definite barrier function to ensure that the error auxiliary is constrained to a predefined neighborhood of zero,which in turn guarantees practical bipartite consensus tracking.A distinguished feature of the proposed controller is its independence on the bound of disturbances,while the input chattering phenomenon is alleviated.Finally,a numerical example is provided to verify the effectiveness of the proposed controller. 展开更多
关键词 barrier functions Practical bipartite consensus Multi-agent systems Signed graphs Sliding-mode control
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A Survey on the Control Lyapunov Function and Control Barrier Function for Nonlinear-Affine Control Systems 被引量:1
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作者 Boqian Li Shiping Wen +2 位作者 Zheng Yan Guanghui Wen Tingwen Huang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第3期584-602,共19页
This survey provides a brief overview on the control Lyapunov function(CLF)and control barrier function(CBF)for general nonlinear-affine control systems.The problem of control is formulated as an optimization problem ... This survey provides a brief overview on the control Lyapunov function(CLF)and control barrier function(CBF)for general nonlinear-affine control systems.The problem of control is formulated as an optimization problem where the optimal control policy is derived by solving a constrained quadratic programming(QP)problem.The CLF and CBF respectively characterize the stability objective and the safety objective for the nonlinear control systems.These objectives imply important properties including controllability,convergence,and robustness of control problems.Under this framework,optimal control corresponds to the minimal solution to a constrained QP problem.When uncertainties are explicitly considered,the setting of the CLF and CBF is proposed to study the input-to-state stability and input-to-state safety and to analyze the effect of disturbances.The recent theoretic progress and novel applications of CLF and CBF are systematically reviewed and discussed in this paper.Finally,we provide research directions that are significant for the advance of knowledge in this area. 展开更多
关键词 Control barrier function(CBF) control Lyapunov function(CLF) nonlinear-affine control systems
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Effects of elafibranor on liver fibrosis and gut barrier function in a mouse model of alcohol-associated liver disease 被引量:5
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作者 Aritoshi Koizumi Kosuke Kaji +10 位作者 Norihisa Nishimura Shohei Asada Takuya Matsuda Misako Tanaka Nobuyuki Yorioka Yuki Tsuji Koh Kitagawa Shinya Sato Tadashi Namisaki Takemi Akahane Hitoshi Yoshiji 《World Journal of Gastroenterology》 SCIE CAS 2024年第28期3428-3446,共19页
BACKGROUND Alcohol-associated liver disease(ALD)is a leading cause of liver-related morbidity and mortality,but there are no therapeutic targets and modalities to prevent ALD-related liver fibrosis.Peroxisome prolifer... BACKGROUND Alcohol-associated liver disease(ALD)is a leading cause of liver-related morbidity and mortality,but there are no therapeutic targets and modalities to prevent ALD-related liver fibrosis.Peroxisome proliferator activated receptor(PPAR)α and δ play a key role in lipid metabolism and intestinal barrier homeostasis,which are major contributors to the pathological progression of ALD.Meanwhile,elafibranor(EFN),which is a dual PPARαand PPARδagonist,has reached a phase III clinical trial for the treatment of metabolic dysfunctionassociated steatotic liver disease and primary biliary cholangitis.However,the benefits of EFN for ALD treatment is unknown.AIM To evaluate the inhibitory effects of EFN on liver fibrosis and gut-intestinal barrier dysfunction in an ALD mouse model.METHODS ALD-related liver fibrosis was induced in female C57BL/6J mice by feeding a 2.5% ethanol(EtOH)-containing Lieber-DeCarli liquid diet and intraperitoneally injecting carbon tetrachloride thrice weekly(1 mL/kg)for 8 weeks.EFN(3 and 10 mg/kg/day)was orally administered during the experimental period.Histological and molecular analyses were performed to assess the effect of EFN on steatohepatitis,fibrosis,and intestinal barrier integrity.The EFN effects on HepG2 lipotoxicity and Caco-2 barrier function were evaluated by cell-based assays.RESULTS The hepatic steatosis,apoptosis,and fibrosis in the ALD mice model were significantly attenuated by EFN treatment.EFN promoted lipolysis and β-oxidation and enhanced autophagic and antioxidant capacities in EtOH-stimulated HepG2 cells,primarily through PPARαactivation.Moreover,EFN inhibited the Kupffer cell-mediated inflammatory response,with blunted hepatic exposure to lipopolysaccharide(LPS)and toll like receptor 4(TLR4)/nuclear factor kappa B(NF-κB)signaling.EFN improved intestinal hyperpermeability by restoring tight junction proteins and autophagy and by inhibiting apoptosis and proinflammatory responses.The protective effect on intestinal barrier function in the EtOH-stimulated Caco-2 cells was predominantly mediated by PPARδ activation.CONCLUSION EFN reduced ALD-related fibrosis by inhibiting lipid accumulation and apoptosis,enhancing hepatocyte autophagic and antioxidant capacities,and suppressing LPS/TLR4/NF-κB-mediated inflammatory responses by restoring intestinal barrier function. 展开更多
关键词 Liver fibrosis ETHANOL Gut barrier function Apoptosis AUTOPHAGY Peroxisome proliferator activated receptor
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Activation of the wnt/β-catenin/CYP1B1 pathway alleviates oxidative stress and protects the blood-brain barrier under cerebral ischemia/reperfusion conditions 被引量:7
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作者 Xingyong Chen Nannan Yao +4 位作者 Yanguang Mao Dongyun Xiao Yiyi Huang Xu Zhang Yinzhou Wang 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1541-1547,共7页
Accumulating evidence suggests that oxidative stress and the Wnt/β-catenin pathway participate in stroke-induced disruption of the blood-brain barrier.However,the potential links between them following ischemic strok... Accumulating evidence suggests that oxidative stress and the Wnt/β-catenin pathway participate in stroke-induced disruption of the blood-brain barrier.However,the potential links between them following ischemic stroke remain largely unknown.The present study found that cerebral ischemia leads to oxidative stress and repression of the Wnt/β-catenin pathway.Meanwhile,Wnt/β-catenin pathway activation by the pharmacological inhibito r,TWS119,relieved oxidative stress,increased the levels of cytochrome P4501B1(CYP1B1)and tight junction-associated proteins(zonula occludens-1[ZO-1],occludin and claudin-5),as well as brain microvascular density in cerebral ischemia rats.Moreove r,rat brain microvascular endothelial cells that underwent oxygen glucose deprivation/reoxygenation displayed intense oxidative stress,suppression of the Wnt/β-catenin pathway,aggravated cell apoptosis,downregulated CYP1B1and tight junction protein levels,and inhibited cell prolife ration and migration.Overexpression ofβ-catenin or knockdown ofβ-catenin and CYP1B1 genes in rat brain mic rovascular endothelial cells at least partly ameliorated or exacerbated these effects,respectively.In addition,small interfering RNA-mediatedβ-catenin silencing decreased CYP1B1 expression,whereas CYP1B1 knoc kdown did not change the levels of glycogen synthase kinase 3β,Wnt-3a,andβ-catenin proteins in rat brain microvascular endothelial cells after oxygen glucose deprivatio n/reoxygenation.Thus,the data suggest that CYP1B1 can be regulated by Wnt/β-catenin signaling,and activation of the Wnt/β-catenin/CYP1B1 pathway contributes to alleviation of oxidative stress,increased tight junction levels,and protection of the blood-brain barrier against ischemia/hypoxia-induced injury. 展开更多
关键词 blood-brain barrier CYP1B1 oxidative stress oxygen glucose deprivation/reoxygenation tight junction vascular endothelial cells Wnt/β-catenin pathway β-catenin
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Blood-brain barrier pathology in cerebral small vessel disease 被引量:5
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作者 Ruxue Jia Gemma Solé-Guardia Amanda J.Kiliaan 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第6期1233-1240,共8页
Cerebral small vessel disease is a neurological disease that affects the brain microvasculature and which is commonly observed among the elderly.Although at first it was considered innocuous,small vessel disease is no... Cerebral small vessel disease is a neurological disease that affects the brain microvasculature and which is commonly observed among the elderly.Although at first it was considered innocuous,small vessel disease is nowadays regarded as one of the major vascular causes of dementia.Radiological signs of small vessel disease include small subcortical infarcts,white matter magnetic resonance imaging hyperintensities,lacunes,enlarged perivascular spaces,cerebral microbleeds,and brain atrophy;however,great heterogeneity in clinical symptoms is observed in small vessel disease patients.The pathophysiology of these lesions has been linked to multiple processes,such as hypoperfusion,defective cerebrovascular reactivity,and blood-brain barrier dysfunction.Notably,studies on small vessel disease suggest that blood-brain barrier dysfunction is among the earliest mechanisms in small vessel disease and might contribute to the development of the hallmarks of small vessel disease.Therefore,the purpose of this review is to provide a new foundation in the study of small vessel disease pathology.First,we discuss the main structural domains and functions of the blood-brain barrier.Secondly,we review the most recent evidence on blood-brain barrier dysfunction linked to small vessel disease.Finally,we conclude with a discussion on future perspectives and propose potential treatment targets and interventions. 展开更多
关键词 blood-brain barrier dysfunction cerebral blood flow cerebral hypoperfusion endothelial dysfunction HYPERTENSION inflammation magnetic resonance imaging neurovascular unit oxidative stress small vessel disease tight junctions TRANSCYTOSIS
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Rebuilding insight into the pathophysiology of Alzheimer’s disease through new blood-brain barrier models 被引量:2
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作者 Kinya Matsuo Hideaki Nshihara 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第9期1954-1960,共7页
The blood-brain barrier is a unique function of the microvasculature in the brain parenchyma that maintains homeostasis in the central nervous system.Blood-brain barrier breakdown is a common pathology in various neur... The blood-brain barrier is a unique function of the microvasculature in the brain parenchyma that maintains homeostasis in the central nervous system.Blood-brain barrier breakdown is a common pathology in various neurological diseases,such as Alzheimer’s disease,stroke,multiple sclerosis,and Parkinson’s disease.Traditionally,it has been considered a consequence of neuroinflammation or neurodegeneration,but recent advanced imaging techniques and detailed studies in animal models show that blood-brain barrier breakdown occurs early in the disease process and may precede neuronal loss.Thus,the blood-brain barrier is attractive as a potential therapeutic target for neurological diseases that lack effective therapeutics.To elucidate the molecular mechanism underlying blood-brain barrier breakdown and translate them into therapeutic strategies for neurological diseases,there is a growing demand for experimental models of human origin that allow for functional assessments.Recently,several human induced pluripotent stem cell-derived blood-brain barrier models have been established and various in vitro blood-brain barrier models using microdevices have been proposed.Especially in the Alzheimer’s disease field,the human evidence for blood-brain barrier dysfunction has been demonstrated and human induced pluripotent stem cell-derived blood-brain barrier models have suggested the putative molecular mechanisms of pathological blood-brain barrier.In this review,we summarize recent evidence of blood-brain barrier dysfunction in Alzheimer’s disease from pathological analyses,imaging studies,animal models,and stem cell sources.Additionally,we discuss the potential future directions for blood-brain barrier research. 展开更多
关键词 Alzheimer’s disease blood-brain barrier human induced pluripotent stem cells
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Astrocytes dynamically regulate the blood-brain barrier in the healthy brain 被引量:1
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作者 AgnėPociūtė Augustas Pivoriūnas Alexei Verkhratsky 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第4期709-710,共2页
The blood-brain barrier(BBB)(discovered and defined by Max Lewandowsky and Lina Stern,and not,as it is universally,and yet erroneously believed,by Paul Ehrlich(Verkhratsky and Pivoriunas,2023))that separates the nervo... The blood-brain barrier(BBB)(discovered and defined by Max Lewandowsky and Lina Stern,and not,as it is universally,and yet erroneously believed,by Paul Ehrlich(Verkhratsky and Pivoriunas,2023))that separates the nervous system from the circulation is evolutionarily conserved from arthropods to man.The primeval BBB of the invertebrates and some early vertebrates was made solely by glial cells and secured(in invertebrates)by septate junctions. 展开更多
关键词 Ehrlich barrier BLOOD
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Numerical simulation on sand sedimentation and erosion characteristics around HDPE sheet sand barrier under different wind angles 被引量:1
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作者 ZHANG Kai ZHANG Peili +3 位作者 ZHANG Hailong TIAN Jianjin WANG Zhenghui XIAO Jianhua 《Journal of Mountain Science》 SCIE CSCD 2024年第2期538-554,共17页
For the safety of railroad operations,sand barriers are utilized to mitigate wind-sand disaster effects.These disasters,characterized by multi-directional wind patterns,result in diverse angles among the barriers.In t... For the safety of railroad operations,sand barriers are utilized to mitigate wind-sand disaster effects.These disasters,characterized by multi-directional wind patterns,result in diverse angles among the barriers.In this study,using numerical simulations,we examined the behavior of High Density Polyethylene(HDPE)sheet sand barriers under different wind angles,focusing on flow field distribution,windproof efficiency,and sedimentation erosion dynamics.This study discovered that at a steady wind speed,airflow velocity varies as the angle between the airflow and the HDPE barrier changes.Specifically,a 90°angle results in the widest low-speed airflow area on the barrier’s downwind side.If the airflow is not perpendicular to the barrier,it prompts a lateral airflow movement which decreases as the angle expands.The windproof efficiency correlates directly with this angle but inversely with the wind’s speed.Notably,with a wind angle of 90°,wind speed drops by 81%.The minimum wind speed is found at 5.1H(the sand barrier height)on the barrier’s downwind side.As the angle grows,the barrier’s windproof efficiency improves,extending its protective reach.Sedimentation is most prominent on the barrier’s downwind side,as the wind angle shifts from 30°to 90°,the sand sedimentation area on the barrier’s downwind side enlarges by 14.8H.As the angle grows,sedimentation intensifies,eventually overtakes the forward erosion and enlarges the sedimentation area. 展开更多
关键词 Multi-wind direction HDPE sheet sand barrier Numerical simulation Windproof efficiency Sedimentation erosion
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Post-acute ischemic stroke hyperglycemia aggravates destruction of the blood-brain barrier 被引量:1
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作者 Tianqi Xu Jianhong Yang +5 位作者 Yao Xu Xiaofeng Wang Xiang Gao Jie Sun Chenhui Zhou Yi Huang 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第6期1344-1350,共7页
Post-acute ischemic stroke hyperglycemia increases the risk of hemorrhagic transformation,which is associated with blood-brain barrier disruption.Brain microvascular endothelial cells are a major component of the bloo... Post-acute ischemic stroke hyperglycemia increases the risk of hemorrhagic transformation,which is associated with blood-brain barrier disruption.Brain microvascular endothelial cells are a major component of the blood-brain barrier.Intercellular mitochondrial transfer has emerged as a novel paradigm for repairing cells with mitochondrial dysfunction.In this study,we first investigated whether mitochondrial transfer exists between brain microvascular endothelial cells,and then investigated the effects of post-acute ischemic stroke hyperglycemia on mitochondrial transfer between brain microvascular endothelial cells.We found that healthy brain microvascular endothelial cells can transfer intact mitochondria to oxygen glucose deprivation-injured brain microvascular endothelial cells.However,post-oxygen glucose deprivation hyperglycemia hindered mitochondrial transfer and exacerbated mitochondrial dysfunction.We established an in vitro brain microvascular endothelial cell model of the blood-brain barrier.We found that post-acute ischemic stroke hyperglycemia reduced the overall energy metabolism levels of brain microvascular endothelial cells and increased permeability of the blood-brain barrier.In a clinical study,we retrospectively analyzed the relationship between post-acute ischemic stroke hyperglycemia and the severity of hemorrhagic transformation.We found that post-acute ischemic stroke hyperglycemia serves as an independent predictor of severe hemorrhagic transformation.These findings suggest that post-acute ischemic stroke hyperglycemia can aggravate disruption of the blood-brain barrier by inhibiting mitochondrial transfer. 展开更多
关键词 acute ischemic stroke blood-brain barrier brain microvascular endothelial cells mitochondrial transfer stress hyperglycemia
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Adaptive Trajectory Tracking Control for Nonholonomic Wheeled Mobile Robots:A Barrier Function Sliding Mode Approach 被引量:1
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作者 Yunjun Zheng Jinchuan Zheng +3 位作者 Ke Shao Han Zhao Hao Xie Hai Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第4期1007-1021,共15页
The trajectory tracking control performance of nonholonomic wheeled mobile robots(NWMRs)is subject to nonholonomic constraints,system uncertainties,and external disturbances.This paper proposes a barrier function-base... The trajectory tracking control performance of nonholonomic wheeled mobile robots(NWMRs)is subject to nonholonomic constraints,system uncertainties,and external disturbances.This paper proposes a barrier function-based adaptive sliding mode control(BFASMC)method to provide high-precision,fast-response performance and robustness for NWMRs.Compared with the conventional adaptive sliding mode control,the proposed control strategy can guarantee that the sliding mode variables converge to a predefined neighborhood of origin with a predefined reaching time independent of the prior knowledge of the uncertainties and disturbances bounds.Another advantage of the proposed algorithm is that the control gains can be adaptively adjusted to follow the disturbances amplitudes thanks to the barrier function.The benefit is that the overestimation of control gain can be eliminated,resulting in chattering reduction.Moreover,a modified barrier function-like control gain is employed to prevent the input saturation problem due to the physical limit of the actuator.The stability analysis and comparative experiments demonstrate that the proposed BFASMC can ensure the prespecified convergence performance of the NWMR system output variables and strong robustness against uncertainties/disturbances. 展开更多
关键词 Adaptive sliding mode barrier function nonholonomic wheeled mobile robot(NWMR) trajectory tracking control
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System barriers to the provision of quality maternal health care in two regional teaching and referral hospitals in Kenya:a qualitative study
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作者 Domisiano Koome Impwii Lucy Kivuti-Bitok 《Global Health Journal》 2023年第4期200-205,共6页
Objective:Sub-Saharan Africa accounts for 66%of global maternal deaths.In Kenya,362 maternal deaths occur in every 100000 live births.Most of these deaths occur as a result of suboptimal quality care of mothers during... Objective:Sub-Saharan Africa accounts for 66%of global maternal deaths.In Kenya,362 maternal deaths occur in every 100000 live births.Most of these deaths occur as a result of suboptimal quality care of mothers during labor,delivery,or within 24h of delivery.This study explored barriers that nurse-midwives encounter in trying to provide high-quality obstetric care during these periods.Methods:A qualitative research design utilizing focus group discussion as part of a mixed method study was used to find out the participants'experiences.Data were collected between February and March 2022 in the maternity units of two regional teaching and referral hospitals in Kenya.Eligible participants were nurse-midwives in charge of the maternity unit.The discussion was conducted in English,tape-recorded,and transcribed verbatim,Data were analyzed thematically,following Braun and Clarke 6-step framework.Nvivo version 7.0 computer software was used to facilitate this process.Results:Two focused group discussions each involving seven participants were conducted.The participants agreed that maternal mortality due to postpartum hemorrhage and pregnancy-induced hypertension is a major health concern.Further,maternal care in the two hospitals was substandard.Themes that emerged as barriers were:inadequate supplies;inadequate obstetric knowledge and skills;shortage of nurse-midwives,and inadequate support supervision.The underlying factors include inadequate funding by the county government and high staff turnover.Conclusion:This study showed that nurse-midwives are working under very difficult circumstances which are hindering the provision of quality maternal care.This is mainly due to system failures and inadequate nursemidwife numbers.Targeted strategies need to be urgently implemented to mitigate these challenges to improve the quality of maternal health care. 展开更多
关键词 Qualitative barriers QUALITY Maternal care system Kenya
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Damage on intestinal barrier function and microbial detoxification of deoxynivalenol:A review
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作者 Jia Chen Xinran Zhang +2 位作者 Ziqi He Dongwei Xiong Miao Long 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第8期2507-2524,共18页
Deoxynivalenol(DON)is a mycotoxin that is produced by various species of Fusarium and is ubiquitous in food and feed.At low concentrations,it can cause metabolic disorders in animals and humans and,at high concentrati... Deoxynivalenol(DON)is a mycotoxin that is produced by various species of Fusarium and is ubiquitous in food and feed.At low concentrations,it can cause metabolic disorders in animals and humans and,at high concentrations,it can lead to pathological changes in the body.The impact of DON on human/animal health and animal productivity has thus attracted a great deal of attention around the world.DON causes severe damage to the intestine,including compromised intestinal barrier,mucosal damage,weakened immune function,and alterations in gut microbiota composition.These effects exacerbate intestinal infections and inflammation in livestock and poultry,posing adverse effects on overall health.Furthermore,research into biological methods for DON detoxification is a crucial avenue for future studies.This includes the utilization of adsorption,enzymatic degradation,and other biological approaches to mitigate DON's impact,offering new strategies for prevention and treatment of DON-induced diseases.Future research will focus on identifying highly efficient detoxifying microorganisms or enzymes to reduce DON levels in food and feed,thereby mitigating its risks to both animals and human health. 展开更多
关键词 deoxynivalenol(DON) intestinal barrier function mucus barrier immune function flora composition biological detoxification
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Breaking the brain barrier:cell competition in neural development and disease
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作者 Patrizia Morciano Daniela Grifoni 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第9期1863-1864,共2页
General information on cell competition:Social behaviors are the basis of biological life.Like species and populations,cell communities experience Darwinian ecological interactions,and in case space and nutrient avail... General information on cell competition:Social behaviors are the basis of biological life.Like species and populations,cell communities experience Darwinian ecological interactions,and in case space and nutrient availability are not uniform throughout the tissue,they begin to compete for ground occupancy. 展开更多
关键词 NEURAL barrier THROUGHOUT
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Dissolvable temporary barrier:a novel paradigm for flexible hydrogel patterning in organ-on-a-chip models
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作者 Ding Wang Qinyu Li +5 位作者 Chenyang Zhou Zhangjie Li Kangyi Lu Yijun Liu Lian Xuan Xiaolin Wang 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第2期153-166,共14页
A combination of hydrogels and microfluidics allows the construction of biomimetic three-dimensional(3D)tissue models in vitro,which are also known as organ-on-a-chipmodels.The hydrogel patterningwith awell-controlled... A combination of hydrogels and microfluidics allows the construction of biomimetic three-dimensional(3D)tissue models in vitro,which are also known as organ-on-a-chipmodels.The hydrogel patterningwith awell-controlled spatial distribution is typically achieved by embedding sophisticated microstructures to act as a boundary.However,these physical barriers inevitably expose cells/tissues to a less physiologically relevant microenvironment than in vivo conditions.Herein,we present a novel dissolvable temporary barrier(DTB)strategy that allows robust and flexible hydrogel patterning with great freedom of design and desirable flow stimuli for cellular hydrogels.The key aspect of this approach is the patterning of a water-soluble rigid barrier as a guiding path for the hydrogel using stencil printing technology,followed by a barrier-free medium perfusion after the dissolution of the DTB.Single and multiple tissue compartments with different geometries can be established using either straight or curved DTB structures.The effectiveness of this strategy is further validated by generating a 3D vascular network through vasculogenesis and angiogenesis using a vascularized microtumor model.As a new proof-of-concept in vasculature-on-a-chip,DTB enables seamless contact between the hydrogel and the culture medium in closed microdevices,which is an improved protocol for the fabrication ofmultiorgan chips.Therefore,we expect it to serve as a promising paradigm for organ-on-a-chip devices for the development of tumor vascularization and drug evaluation in the future preclinical studies. 展开更多
关键词 Dissolvable temporary barrier Hydrogel patterning Microfluidics Organ-on-a-chip Vascularization
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Probiotic Pediococcus pentosaceus restored gossypol-induced intestinal barrier injury by increasing propionate content in Nile tilapia
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作者 Feifei Ding Nannan Zhou +5 位作者 Yuan Luo Tong Wang Weijie Li Fang Qiao Zhenyu Du Meiling Zhang 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第4期1688-1703,共16页
Background Intestinal barrier is a dynamic interface between the body and the ingested food components, however, dietary components or xenobiotics could compromise intestinal integrity, causing health risks to the hos... Background Intestinal barrier is a dynamic interface between the body and the ingested food components, however, dietary components or xenobiotics could compromise intestinal integrity, causing health risks to the host. Gossypol, a toxic component in cottonseed meal(CSM), caused intestinal injury in fish or other monogastric animals. It has been demonstrated that probiotics administration benefits the intestinal barrier integrity, but the efficacy of probiotics in maintaining intestinal health when the host is exposed to gossypol remains unclear. Here, a strain(YC) affiliated to Pediococcus pentosaceus was isolated from the gut of Nile tilapia(Oreochromis niloticus) and its potential to repair gossypol-induced intestinal damage was evaluated.Results A total of 270 Nile tilapia(2.20 ± 0.02 g) were allotted in 3 groups with 3 tanks each and fed with 3 diets including CON(control diet), GOS(control diet containing 300 mg/kg gossypol) and GP(control diet containing 300 mg/kg gossypol and 10^(8) colony-forming unit(CFU)/g P. pentosaceus YC), respectively. After 10 weeks, addition of P. pentosaceus YC restored growth retardation and intestinal injury induced by gossypol in Nile tilapia. Transcriptome analysis and si RNA interference experiments demonstrated that NOD-like receptors(NLR) family caspase recruitment domain(CARD) domain containing 3(Nlrc3) inhibition might promote intestinal stem cell(ISC) proliferation, as well as maintaining gut barrier integrity. 16S r RNA sequencing and gas chromatography-mass spectrometry(GC-MS) revealed that addition of P. pentosaceus YC altered the composition of gut microbiota and increased the content of propionate in fish gut. In vitro studies on propionate's function demonstrated that it suppressed nlrc3 expression and promoted wound healing in Caco-2 cell model.Conclusions The present study reveals that P. pentosaceus YC has the capacity to ameliorate intestinal barrier injury by modulating gut microbiota composition and elevating propionate level. This finding offers a promising strategy for the feed industry to incorporate cottonseed meal into fish feed formulations. 展开更多
关键词 Gut barrier injury GOSSYPOL ISCs proliferation Nlrc3 PROPIONATE
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