Objective To summarize experience of establishing stable rat model ot chronic allograft nephropathy. Methods We used Fisher rats as donors and Lewis rats as recipients. After left kidney of donor perfused in situ unde...Objective To summarize experience of establishing stable rat model ot chronic allograft nephropathy. Methods We used Fisher rats as donors and Lewis rats as recipients. After left kidney of donor perfused in situ under hypothermic condition,left renal vein,abdominal aorta and bladder flap of donor was anastomosed with展开更多
Cardiac injury initiates repair mechanisms and results in cardiac remodeling and fi-brosis,which appears to be a leading cause of cardiovascular diseases.Cardiac fi-brosis is characterized by the accumulation of extra...Cardiac injury initiates repair mechanisms and results in cardiac remodeling and fi-brosis,which appears to be a leading cause of cardiovascular diseases.Cardiac fi-brosis is characterized by the accumulation of extracellular matrix proteins,mainly collagen in the cardiac interstitium.Many experimental studies have demonstrated that fibrotic injury in the heart is reversible;therefore,it is vital to understand differ-ent molecular mechanisms that are involved in the initiation,progression,and resolu-tion of cardiac fibrosis to enable the development of antifibrotic agents.Of the many experimental models,one of the recent models that has gained renewed interest is isoproterenol(ISP)-induced cardiac fibrosis.ISP is a synthetic catecholamine,sympa-thomimetic,and nonselectiveβ-adrenergic receptor agonist.The overstimulated and sustained activation ofβ-adrenergic receptors has been reported to induce biochemi-cal and physiological alterations and ultimately result in cardiac remodeling.ISP has been used for decades to induce acute myocardial infarction.However,the use of low doses and chronic administration of ISP have been shown to induce cardiac fibrosis;this practice has increased in recent years.Intraperitoneal or subcutaneous ISP has been widely used in preclinical studies to induce cardiac remodeling manifested by fibrosis and hypertrophy.The induced oxidative stress with subsequent perturbations in cellular signaling cascades through triggering the release of free radicals is consid-ered the initiating mechanism of myocardial fibrosis.ISP is consistently used to induce fibrosis in laboratory animals and in cardiomyocytes isolated from animals.In recent years,numerous phytochemicals and synthetic molecules have been evaluated in ISP-induced cardiac fibrosis.The present review exclusively provides a comprehensive summary of the pathological biochemical,histological,and molecular mechanisms of ISP in inducing cardiac fibrosis and hypertrophy.It also summarizes the application of this experimental model in the therapeutic evaluation of natural as well as syn-thetic compounds to demonstrate their potential in mitigating myocardial fibrosis and hypertrophy.展开更多
Neuromyelitis optica spectrum disorders are neuroinflammatory demyelinating disorders that lead to permanent visual loss and motor dysfunction.To date,no effective treatment exists as the exact causative mechanism rem...Neuromyelitis optica spectrum disorders are neuroinflammatory demyelinating disorders that lead to permanent visual loss and motor dysfunction.To date,no effective treatment exists as the exact causative mechanism remains unknown.Therefore,experimental models of neuromyelitis optica spectrum disorders are essential for exploring its pathogenesis and in screening for therapeutic targets.Since most patients with neuromyelitis optica spectrum disorders are seropositive for IgG autoantibodies against aquaporin-4,which is highly expressed on the membrane of astrocyte endfeet,most current experimental models are based on aquaporin-4-IgG that initially targets astrocytes.These experimental models have successfully simulated many pathological features of neuromyelitis optica spectrum disorders,such as aquaporin-4 loss,astrocytopathy,granulocyte and macrophage infiltration,complement activation,demyelination,and neuronal loss;however,they do not fully capture the pathological process of human neuromyelitis optica spectrum disorders.In this review,we summarize the currently known pathogenic mechanisms and the development of associated experimental models in vitro,ex vivo,and in vivo for neuromyelitis optica spectrum disorders,suggest potential pathogenic mechanisms for further investigation,and provide guidance on experimental model choices.In addition,this review summarizes the latest information on pathologies and therapies for neuromyelitis optica spectrum disorders based on experimental models of aquaporin-4-IgG-seropositive neuromyelitis optica spectrum disorders,offering further therapeutic targets and a theoretical basis for clinical trials.展开更多
This article aims tomodel and analyze the heat and fluid flow characteristics of a carboxymethyl cellulose(CMC)nanofluid within a convergent-divergent shaped microchannel(Two-dimensional).The base fluid,water+CMC(0.5%...This article aims tomodel and analyze the heat and fluid flow characteristics of a carboxymethyl cellulose(CMC)nanofluid within a convergent-divergent shaped microchannel(Two-dimensional).The base fluid,water+CMC(0.5%),is mixed with CuO and Al2O3 nanoparticles at volume fractions of 0.5%and 1.5%,respectively.The research is conducted through the conjugate usage of experimental and theoretical models to represent more realistic properties of the non-Newtonian nanofluid.Three types of microchannels including straight,divergent,and convergent are considered,all having the same length and identical inlet cross-sectional area.Using ANSYS FLUENT software,Navier-Stokes equations are solved for the laminar flow of the non-Newtonian nanofluid.The study examines the effects of Reynolds number,nanoparticle concentration and type,and microchannel geometry on flow and heat transfer.The results prove that the alumina nanoparticles outperform copper oxide in increasing the Nusselt number at a 0.5% volume fraction,while copper oxide nanoparticles excel at a 1.5%volume fraction.Moreover,in the selected case study,as the Reynolds number increases from 100 to 500,the Nusselt number rises by 56.26% in straight geometry,52.93% in divergent geometry,and 59.10%in convergent geometry.Besides,the Nusselt number enhances by 18.75% when transitioning from straight to convergent geometry at a Reynolds number of 500,and by 19.81%at a Reynolds number of 1000.Finally,the results of the research depict that the use of thermophysical properties derived from the experimental achievements,despite creating complexity in the modeling and the solution method,leads to more accurate and realistic outputs.展开更多
With the increasing development of deepburied engineering projects,rockburst disasters have become a frequent concern.Studies have indicated that tunnel diameter is a critical factor influencing the occurrence of rock...With the increasing development of deepburied engineering projects,rockburst disasters have become a frequent concern.Studies have indicated that tunnel diameter is a critical factor influencing the occurrence of rockbursts.To investigate the influence of tunnel diameter on the deformation and failure characteristics of surrounding rock,large-sized rocklike gypsum specimens were tested using a selfdeveloped true triaxial rockburst loading system containing circular tunnels with three different diameters(D=0.07 m,0.11 m,and 0.15 m).Acoustic emission monitoring,together with a miniature intelligent camera,was employed to analyze the entire process,focusing on macroscopic failure patterns,fragment characteristics,and underlying failure mechanisms.In addition,theoretical analyses were carried out and combined with numerical simulations to investigate the differences in energy evolution associated with rockburst physical models.The results indicate that:(1)The rockburst process with different tunnel diameters consistently evolved through three distinct stages—initial particle ejection,crack propagation accompanied by flake spalling,and,finally,fragment ejection leading to the formation of a‘V'-shaped notch.(2)Increasing tunnel diameter reduces rockburst failure load while increasing surrounding rock damage extent,total mass and average size of ejected fragments.Additionally,shear failure proportion decreases with tensile failure becoming increasingly dominant.(3)Larger tunnel diameters reduce the attenuation rate of elastic strain energy,thereby expanding the zone of elastic strain energy accumulation and disturbance and creating conditions for larger volume rockburst.(4)Larger tunnel diameters result in a smaller principal stress ratio at equivalent distances in the surrounding rock,indicating a higher likelihood of tensile failure.(5)Numerical analyses further reveal that larger tunnel diameters reduce the maximum elastic strain energy density around the tunnel,lowering the energy released per unit volume of rockburst fragments and their ejection velocities.However,both the total failure volume and overall energy release from rockburst increase.Model experiments with different tunnel diameters are of great significance for optimizing engineering design and parameter selection,as well as guiding tunnel construction under complex geological conditions.展开更多
Membrane-assisted antisolvent crystallization(MAAC)is a separation process that allows for precise regulation of the crystallization process in pharmaceutical,finechemical engineering,energy chemistry,etc.After decade...Membrane-assisted antisolvent crystallization(MAAC)is a separation process that allows for precise regulation of the crystallization process in pharmaceutical,finechemical engineering,energy chemistry,etc.After decades of development,the current MAAC engineering lacks highly robust specialized instruments,which limits the further industrial application of the MAAC process.Herein,to guide the design and optimization of the advanced MAAC instrument(DUT-iMC),we developed a parameter evaluation strategy based on cold model experiments.This approach utilizes the average particle size variation rate and the counts variation rate to characterize crystal size changes.The layout of the internal membrane module in DUT-iMC and the arrangement of the conveying pipeline were optimized.This improvement enhanced particle conveying characteristics,promoting more efficienttransport and circulation within the module.The advanced MAAC instrument substantially automates the production process,and the internal probes accurately monitor and record process variables,allowing for precise regulation of crystal size and morphology.The optimal operating range was expanded by 150%compared to the laboratory instrument.The range of shell side flow rate options increased by 50%,and the production time can be shortened by up to 30%.This paper provides ideas and guidance for the industrialization of MAAC processes and the development of related instruments.展开更多
The Editor-in-Chief has retracted this article.Following this publication,concerns were raised regarding the similarity of images presented in this article with previously published articles[1,2].The authors were unab...The Editor-in-Chief has retracted this article.Following this publication,concerns were raised regarding the similarity of images presented in this article with previously published articles[1,2].The authors were unable to provide a satisfactory explanation and raw data for the concerns upon request.展开更多
In order to check the validity of the mathematical model for analyzing the flow field in the air-agitated seed precipitation tank,a scaled down experimental apparatus was designed and the colored tracer and KCl tracer...In order to check the validity of the mathematical model for analyzing the flow field in the air-agitated seed precipitation tank,a scaled down experimental apparatus was designed and the colored tracer and KCl tracer were added in the apparatus to follow the real flow line.Virtue tracers were considered in the mathematical model and the algorithm of tracers was built.The comparison of the results between the experiment and numerical calculation shows that the time of the tracer flows out of stirring tube are 40 s in the experiment and 42 s in numerical calculated result.The transient diffusion process and the solution residence time of the numerical calculation are in good agreement with the experimental results,which indicates that the mathematical model is reliable and can be used to predict the flow field of the air-agitated seed precipitation tank.展开更多
Objective The present study aimed to establish a cerebral schistosomiasis model in rabbits,to provide a valuable tool for morphological analysis,clinical manifestation observation,as well as investigations into immuno...Objective The present study aimed to establish a cerebral schistosomiasis model in rabbits,to provide a valuable tool for morphological analysis,clinical manifestation observation,as well as investigations into immunological reactions and pathogenesis of focal inflammatory reaction in neuroschistosomiasis（NS）.Methods Sixty New Zealand rabbits were randomly assigned into operation,sham-operation and normal groups.Rabbits in the operation group received direct injection of dead schistosome eggs into the brain,while their counterparts in the sham-operation group received saline injection.Rabbits in the normal group received no treatment.Base on the clinical manifestations,rabbits were sacrificed on days 3,5,7,10,20,and 30 post injection,and brain samples were sectioned and stained with hematoxylin-eosin.Sections were observed under the microscope.Results The rabbits in the operation group exhibited various neurological symptoms,including anorexy,partial and general seizures,and paralysis.The morphological analysis showed several schistosome eggs in the nervous tissue on day 3 post operation,with very mild inflammation.On days 7-10 post operation,several schistosome eggs were localized in proximity to red blood cells with many neutrophilic granulocytes and eosinophilic granulocytes around them.The schistosome eggs developed into the productive granuloma stage on days 14-20 post operation.On day 30,the schistosome eggs were found to be in the healing-by-fibrosis stage,and the granuloma area was replaced by fibrillary glia through astrocytosis.The sham-operation group and the normal group showed negative results.Conclusion This method might be used to establish the cerebral schistosomiasis experimental model.Several factors need to be considered in establishing this model,such as the antigenic property of eggs,the time of scarification,and the clinical manifestations.展开更多
Wide angle acquisition has been taken as a significant measure to obtain high quality seismic data and is getting greater attention, In this paper, we discuss ocean bottom cable （OBC） seismic wide angle reflections ...Wide angle acquisition has been taken as a significant measure to obtain high quality seismic data and is getting greater attention, In this paper, we discuss ocean bottom cable （OBC） seismic wide angle reflections on the basis of a layered model experiment. Some experiment results don＇t support theoretical conclusions. The main experimental conclusions are： 1. Wide angle reflection energies are stronger than non-wide-angle reflections （up to twice as strong） but there is a big difference between observations and theoretical calculations that suggest the wide angle reflection energies are 15 times the non- wide-angle reflection energy. The reflection energy increases gradually rather than sharply as the theoretical calculations suggest. 2. The reflection events remain hyperbolic when the offset increases. 3. Wide angle reflection dominant frequency is about 20-30% less than non- wide-angle reflections and decreases as the offset increases. The non-wide-angle reflection dominant frequency shows no obvious variation for small offsets. 4. There is no wave shape mutation or polarity reversal near the critical angle. 5. The reflection event group features are the same for both cases of incidence angle greater and less than the critical angle. 6. Direct arrivals, multiples, and water bottom refractions influence the wide angle reflections of the sea floor.展开更多
Inflammation is a common disease involved in the pathogenesis,complications,and sequelae of a large number of related diseases,and therefore considerable research has been directed toward developing anti-inflammatory ...Inflammation is a common disease involved in the pathogenesis,complications,and sequelae of a large number of related diseases,and therefore considerable research has been directed toward developing anti-inflammatory drugs for the prevention and treatment of these diseases.Traditional Chinese medicine(TCM)has been used to treat inflammatory and related diseases since ancient times.According to the re-view of abundant modern scientific researches,it is suggested that TCM exhibit anti-inflammatory effects at different levels,and via multiple pathways with various targets,and recently a series of in vitro and in vivo anti-inflammatory models have been developed for anti-inflammation research in TCM.Currently,the reported classic mechanisms of TCM and experimental models of its anti-inflammatory effects pro-vide reference points and guidance for further research and development of TCM.Importantly,the research clearly confirms that TCM is now and will continue to be an effective form of treatment for many types of inflammation and inflammation-related diseases.展开更多
Epilepsy is a common and serious neurological disease that causes recurrent seizures. The brain damage caused by seizures can lead to depression, anxiety, cognitive impairment, or disability. In almost all cases chron...Epilepsy is a common and serious neurological disease that causes recurrent seizures. The brain damage caused by seizures can lead to depression, anxiety, cognitive impairment, or disability. In almost all cases chronic seizures are difficult to cure. MicroRNAs are widely expressed in the central nervous system and play important roles in the pathogenesis of several neurological disorders, including epilepsy. A variety of animals(mostly mice and rats) have been used to induce experimental epilepsy using different protocols and miRNA profiling performed. Most of the recent studies reviewed had performed miRNA profiling in hippocampal tissues and a large number of microRNAs were dysregulated when compared to controls. Most notably, miR-132-3p,-146a-5p,-10a-5p,-21a-3p,-27a-3p,-142a-5p,-212-3p,-431-5p, and-155 were upregulated in both the mouse and rat studies. Overexpression of miR-137 and miR-219 decreased seizure severity in a mouse epileptic model, and suppression of miR-451,-10a-5p,-21a-5p,-27a-5p,-142a-5p,-431-5p,-155, and-134 had a positive influence on seizure behavior. In the rat studies, overexpression of miR-139-5p decreased neuronal damage in drug-resistant rats and inhibition of miR-129-2-3p,-27a-3p,-155,-134,-181a, and-146a had a positive effect on seizure behavior and/or reduced the loss of neuronal cells. Further studies are warranted using adult female and immature male and female animals. It would also be helpful to test the ability of specific agomirs and antagomirs to control seizure activity in a subhuman primate model of epilepsy such as adult marmosets injected intraperitoneally with pilocarpine or cynomolgus monkeys given intrahippocampal injections of kainic acid.展开更多
Using physical simulation models, rainfall-induced landslides have been simulated under various rainfall intensities. During these simulations, we have monitored the physical and mechanical behaviors of the landslide ...Using physical simulation models, rainfall-induced landslides have been simulated under various rainfall intensities. During these simulations, we have monitored the physical and mechanical behaviors of the landslide over the slip surface at different heights of the model slopes, as well as taking the whole slope to identify its deformation and failure processes. The results show that the rainfall duration corresponding to the initiation of the debris landslide and is exponentially related to rainfall intensity. Corresponding to the three intervals of the rainfall intensity, there are three types of slope failure modes:(1) the small-slump failure at the leading edge of the slope;(2) the block-slump failure but sometimes there are large blocks sliding down;and(3) the bulk failure but sometimes there is the block-slump failure. Based on the total rainfall-lasting time and the associated proportion of failed mass volume, the early warning of debris landslide can be classified into five grades, i.e., red, orange to red, orange, yellow to orange and yellow, which correspond to the five slope failure modes, respectively.展开更多
To predict the flutter dynamic pressure of a wind tunnel model before flutter test,an accurate Computational Fluid Dynamics/Computational Structural Dynamics(CFD/CSD)-based flutter prediction method is proposed under ...To predict the flutter dynamic pressure of a wind tunnel model before flutter test,an accurate Computational Fluid Dynamics/Computational Structural Dynamics(CFD/CSD)-based flutter prediction method is proposed under the conditions of a 2.4 m×2.4 m transonic wind tunnel with porous wall.From the CFD simulations of the flows through an inclined hole of this wind tunnel,the Nambu's linear porous wall model between the flow rate and the differential pressure is extended to the porous wall with inclined holes,so that the porous wall can be conveniently modeled as a boundary condition.According to the flutter testing approach for the current wind tunnel,the steady CFD calculation is conducted to achieve the required inlet Mach number.A timedomain CFD/CSD method is then employed to evaluate the structural response of the experimental model,and the critical flutter point is obtained by increasing the dynamic pressure step by step at a fixed Mach number.The present method is applied to the flutter calculations for a vertical tail model and an aircraft model tested in the current transonic wind tunnel.For both models,the computed flutter characteristics agree well with the experimental results.展开更多
Located at the northwest continental slope of the South China Sea, the Qiongdongnan Basin bears valley-shaped bathymetry deepening toward east. It is separated from the Yinggehai Basin through NW-trending Indo-China-R...Located at the northwest continental slope of the South China Sea, the Qiongdongnan Basin bears valley-shaped bathymetry deepening toward east. It is separated from the Yinggehai Basin through NW-trending Indo-China-Red River shear zone, and connected with NW subsea basin through the Xisha Trough. Along with the rapid progress of the deepwater exploration, large amounts of high resolution geophysical and geological data were accumulated. Scientific researches about deepwater basins kept revealing brand new tectonic and sedimentary discoveries. In order to summarize the structural features and main controlling factors of the deepwater Qiongdongnan Basin, a series of researches on basin architecture, fault activities, tectonic deformation and evolution were carried out. In reference to analogue modeling experiments, a tectonic situation and a basin formation mechanism were discussed. The researches indicate that：the northern boundary of the Qiongdongnan Basin is strongly controlled by No. 2 fault. The overlapping control of two stress fields from the east and the west made the central depression zone extremely thinned. Combined with the changed stress field, the segmentation of a preexisting weakness zone made the sags in the east experiencing different rifting histories from the west ones. The NE-trending west segment of the Qiongdongnan Basin experienced strong rifting during Eocene, while the roughly EW-trending sags in the east segment show strong rifting during late Eocene and early Oligocene. Local structures such as NW-trending basal fault and inherited uplifts controlled the lateral segmentation. So first order factors such as regional stress field and preexisting weakness zone controlled the basin zonation, while the second order factors determined the segmentation from east to west.展开更多
Viral infections have led to many public health crises and pandemics in the last few centuries.Neurotropic virus infection-induced viral encephalitis(VE),especially the symptomatic inflammation of the meninges and bra...Viral infections have led to many public health crises and pandemics in the last few centuries.Neurotropic virus infection-induced viral encephalitis(VE),especially the symptomatic inflammation of the meninges and brain parenchyma,has attracted growing attention due to its high mortality and disability rates.Understanding the infectious routes of neurotropic viruses and the mechanism underlying the host immune response is critical to reduce viral spread and improve antiviral therapy outcomes.In this review,we summarize the common categories of neurotropic viruses,viral transmission routes in the body,host immune responses,and experimental animal models used for VE study to gain a deeper understanding of recent progress in the pathogenic and immunological mechanisms under neurotropic viral infection.This review should provide valuable resources and perspectives on how to cope with pandemic infections.展开更多
To determine the ultimate bearing capacity of foundations on sloping ground surface in practice, energy dissipation method was used to formulate the beating capacity as programming problem, and full-scale model experi...To determine the ultimate bearing capacity of foundations on sloping ground surface in practice, energy dissipation method was used to formulate the beating capacity as programming problem, and full-scale model experiments were investigated to analyze the performance of the soil slopes loaded by a strip footing in laboratory. The soil failure is governed by a linear Mohr-Coulomb yield criterion, and soil deformation follows an associated flow rule. Based on the energy dissipation method of plastic mechanics, a multi-wedge translational failure mechanism was employed to obtain the three bearing capacity factors related to cohesion, equivalent surcharge load and the unit gravity for various slope inclination angles. Numerical results were compared with those of the published solutions using finite element method and those of model experiments. The bearing capacity factors were presented in the form of design charts for practical use in engineering. The results show that limit analysis solutions approximate to those of model tests, and that the energy dissipation method is effective to estimate bearing capacity of soil slope.展开更多
A series of plane-strain physical model experiments are carried out to study the spatiotemporal evolution rule of rocks fracture surrounding gob-side roadway, which is subjected to the pressure induced by the mining p...A series of plane-strain physical model experiments are carried out to study the spatiotemporal evolution rule of rocks fracture surrounding gob-side roadway, which is subjected to the pressure induced by the mining process. The digital photogrammetry technology and large deformation analysis method are applied to measure the deformation and fracture of surrounding rocks. The experimental results indicate that the deformation and fracture of coal pillars are the cause to the instability and failure of the surrounding rocks. The spatiotemporal evolution rule of the rock deformation and fracture surrounding gob-side roadway is obtained. The coal pillar and the roof near coal pillar should be strengthened in support design. The engineering application results also can provide a useful guide that the combined support with wire meshes, beam, anchor bolt and cable is an effective method.展开更多
AIM To investigate a safer way to set up the disease model of cystic echinococcosis without contamination risk and develop a novel experimental murine model of hepatic cystic echinococcosis. METHODS C57 B/6 mice were ...AIM To investigate a safer way to set up the disease model of cystic echinococcosis without contamination risk and develop a novel experimental murine model of hepatic cystic echinococcosis. METHODS C57 B/6 mice were injected with human protoscolices of three different concentrations via the portal vein. The mice were followed for 10 mo by ultrasound,gross anatomy,and pathological and immunological examinations. The protoscolex migration in the portal vein,hydatid cyst growth,host immune reaction,and hepatic histopathology were examined periodically.RESULTS The infection rates in the mice in the high,medium,and low concentration groups were 90%,100%,and 63.6%,respectively. The protoscolices migrated in the portal vein with blood flow,settled in the liver,and developed into orthotopic hepatic hydatid cysts,resembling the natural infection route and course.CONCLUSION We have established an improved experimental model of hepatic cystic echinococcosis with low biohazard risk but stable growing dynamics and immune reaction. It is especially useful for new anti-parasite medication trials against hydatid disease.展开更多
An estimated 130 million people worldwide are chronically infected with hepatitis C virus (HCV) making it a leading cause of liver disease worldwide. Because the currently available therapy of pegylated interferon-alp...An estimated 130 million people worldwide are chronically infected with hepatitis C virus (HCV) making it a leading cause of liver disease worldwide. Because the currently available therapy of pegylated interferon-alpha and ribavirin is only effective in a subset of patients, the development of new HCV antivirals is a healthcare imperative. This review discusses the experimental models available for HCV antiviral drug research, recent advances in HCV antiviral drug development, as well as active research being pursued to facilitate development of new HCV-specific therapeutics.展开更多
文摘Objective To summarize experience of establishing stable rat model ot chronic allograft nephropathy. Methods We used Fisher rats as donors and Lewis rats as recipients. After left kidney of donor perfused in situ under hypothermic condition,left renal vein,abdominal aorta and bladder flap of donor was anastomosed with
基金United Arab Emirates University,Grant/Award Number:12R104 and 12R121。
文摘Cardiac injury initiates repair mechanisms and results in cardiac remodeling and fi-brosis,which appears to be a leading cause of cardiovascular diseases.Cardiac fi-brosis is characterized by the accumulation of extracellular matrix proteins,mainly collagen in the cardiac interstitium.Many experimental studies have demonstrated that fibrotic injury in the heart is reversible;therefore,it is vital to understand differ-ent molecular mechanisms that are involved in the initiation,progression,and resolu-tion of cardiac fibrosis to enable the development of antifibrotic agents.Of the many experimental models,one of the recent models that has gained renewed interest is isoproterenol(ISP)-induced cardiac fibrosis.ISP is a synthetic catecholamine,sympa-thomimetic,and nonselectiveβ-adrenergic receptor agonist.The overstimulated and sustained activation ofβ-adrenergic receptors has been reported to induce biochemi-cal and physiological alterations and ultimately result in cardiac remodeling.ISP has been used for decades to induce acute myocardial infarction.However,the use of low doses and chronic administration of ISP have been shown to induce cardiac fibrosis;this practice has increased in recent years.Intraperitoneal or subcutaneous ISP has been widely used in preclinical studies to induce cardiac remodeling manifested by fibrosis and hypertrophy.The induced oxidative stress with subsequent perturbations in cellular signaling cascades through triggering the release of free radicals is consid-ered the initiating mechanism of myocardial fibrosis.ISP is consistently used to induce fibrosis in laboratory animals and in cardiomyocytes isolated from animals.In recent years,numerous phytochemicals and synthetic molecules have been evaluated in ISP-induced cardiac fibrosis.The present review exclusively provides a comprehensive summary of the pathological biochemical,histological,and molecular mechanisms of ISP in inducing cardiac fibrosis and hypertrophy.It also summarizes the application of this experimental model in the therapeutic evaluation of natural as well as syn-thetic compounds to demonstrate their potential in mitigating myocardial fibrosis and hypertrophy.
文摘Neuromyelitis optica spectrum disorders are neuroinflammatory demyelinating disorders that lead to permanent visual loss and motor dysfunction.To date,no effective treatment exists as the exact causative mechanism remains unknown.Therefore,experimental models of neuromyelitis optica spectrum disorders are essential for exploring its pathogenesis and in screening for therapeutic targets.Since most patients with neuromyelitis optica spectrum disorders are seropositive for IgG autoantibodies against aquaporin-4,which is highly expressed on the membrane of astrocyte endfeet,most current experimental models are based on aquaporin-4-IgG that initially targets astrocytes.These experimental models have successfully simulated many pathological features of neuromyelitis optica spectrum disorders,such as aquaporin-4 loss,astrocytopathy,granulocyte and macrophage infiltration,complement activation,demyelination,and neuronal loss;however,they do not fully capture the pathological process of human neuromyelitis optica spectrum disorders.In this review,we summarize the currently known pathogenic mechanisms and the development of associated experimental models in vitro,ex vivo,and in vivo for neuromyelitis optica spectrum disorders,suggest potential pathogenic mechanisms for further investigation,and provide guidance on experimental model choices.In addition,this review summarizes the latest information on pathologies and therapies for neuromyelitis optica spectrum disorders based on experimental models of aquaporin-4-IgG-seropositive neuromyelitis optica spectrum disorders,offering further therapeutic targets and a theoretical basis for clinical trials.
文摘This article aims tomodel and analyze the heat and fluid flow characteristics of a carboxymethyl cellulose(CMC)nanofluid within a convergent-divergent shaped microchannel(Two-dimensional).The base fluid,water+CMC(0.5%),is mixed with CuO and Al2O3 nanoparticles at volume fractions of 0.5%and 1.5%,respectively.The research is conducted through the conjugate usage of experimental and theoretical models to represent more realistic properties of the non-Newtonian nanofluid.Three types of microchannels including straight,divergent,and convergent are considered,all having the same length and identical inlet cross-sectional area.Using ANSYS FLUENT software,Navier-Stokes equations are solved for the laminar flow of the non-Newtonian nanofluid.The study examines the effects of Reynolds number,nanoparticle concentration and type,and microchannel geometry on flow and heat transfer.The results prove that the alumina nanoparticles outperform copper oxide in increasing the Nusselt number at a 0.5% volume fraction,while copper oxide nanoparticles excel at a 1.5%volume fraction.Moreover,in the selected case study,as the Reynolds number increases from 100 to 500,the Nusselt number rises by 56.26% in straight geometry,52.93% in divergent geometry,and 59.10%in convergent geometry.Besides,the Nusselt number enhances by 18.75% when transitioning from straight to convergent geometry at a Reynolds number of 500,and by 19.81%at a Reynolds number of 1000.Finally,the results of the research depict that the use of thermophysical properties derived from the experimental achievements,despite creating complexity in the modeling and the solution method,leads to more accurate and realistic outputs.
基金funded by the National Natural Science Foundation of China(Nos.42077228,52174085)。
文摘With the increasing development of deepburied engineering projects,rockburst disasters have become a frequent concern.Studies have indicated that tunnel diameter is a critical factor influencing the occurrence of rockbursts.To investigate the influence of tunnel diameter on the deformation and failure characteristics of surrounding rock,large-sized rocklike gypsum specimens were tested using a selfdeveloped true triaxial rockburst loading system containing circular tunnels with three different diameters(D=0.07 m,0.11 m,and 0.15 m).Acoustic emission monitoring,together with a miniature intelligent camera,was employed to analyze the entire process,focusing on macroscopic failure patterns,fragment characteristics,and underlying failure mechanisms.In addition,theoretical analyses were carried out and combined with numerical simulations to investigate the differences in energy evolution associated with rockburst physical models.The results indicate that:(1)The rockburst process with different tunnel diameters consistently evolved through three distinct stages—initial particle ejection,crack propagation accompanied by flake spalling,and,finally,fragment ejection leading to the formation of a‘V'-shaped notch.(2)Increasing tunnel diameter reduces rockburst failure load while increasing surrounding rock damage extent,total mass and average size of ejected fragments.Additionally,shear failure proportion decreases with tensile failure becoming increasingly dominant.(3)Larger tunnel diameters reduce the attenuation rate of elastic strain energy,thereby expanding the zone of elastic strain energy accumulation and disturbance and creating conditions for larger volume rockburst.(4)Larger tunnel diameters result in a smaller principal stress ratio at equivalent distances in the surrounding rock,indicating a higher likelihood of tensile failure.(5)Numerical analyses further reveal that larger tunnel diameters reduce the maximum elastic strain energy density around the tunnel,lowering the energy released per unit volume of rockburst fragments and their ejection velocities.However,both the total failure volume and overall energy release from rockburst increase.Model experiments with different tunnel diameters are of great significance for optimizing engineering design and parameter selection,as well as guiding tunnel construction under complex geological conditions.
基金financial contribution from the National Natural Science Foundation of China(22021005,22378041)Supporting Plan of Scientificand Technology Innovative Talents in Dalian(2023RJ001)Central Guidance on Local Science and Technology Development Fund of Liaoning Province(2025040052-JH6/1011)。
文摘Membrane-assisted antisolvent crystallization(MAAC)is a separation process that allows for precise regulation of the crystallization process in pharmaceutical,finechemical engineering,energy chemistry,etc.After decades of development,the current MAAC engineering lacks highly robust specialized instruments,which limits the further industrial application of the MAAC process.Herein,to guide the design and optimization of the advanced MAAC instrument(DUT-iMC),we developed a parameter evaluation strategy based on cold model experiments.This approach utilizes the average particle size variation rate and the counts variation rate to characterize crystal size changes.The layout of the internal membrane module in DUT-iMC and the arrangement of the conveying pipeline were optimized.This improvement enhanced particle conveying characteristics,promoting more efficienttransport and circulation within the module.The advanced MAAC instrument substantially automates the production process,and the internal probes accurately monitor and record process variables,allowing for precise regulation of crystal size and morphology.The optimal operating range was expanded by 150%compared to the laboratory instrument.The range of shell side flow rate options increased by 50%,and the production time can be shortened by up to 30%.This paper provides ideas and guidance for the industrialization of MAAC processes and the development of related instruments.
文摘The Editor-in-Chief has retracted this article.Following this publication,concerns were raised regarding the similarity of images presented in this article with previously published articles[1,2].The authors were unable to provide a satisfactory explanation and raw data for the concerns upon request.
基金Project(07JJ4016) supported by the Natural Science Foundation of Hunan Procvince,China
文摘In order to check the validity of the mathematical model for analyzing the flow field in the air-agitated seed precipitation tank,a scaled down experimental apparatus was designed and the colored tracer and KCl tracer were added in the apparatus to follow the real flow line.Virtue tracers were considered in the mathematical model and the algorithm of tracers was built.The comparison of the results between the experiment and numerical calculation shows that the time of the tracer flows out of stirring tube are 40 s in the experiment and 42 s in numerical calculated result.The transient diffusion process and the solution residence time of the numerical calculation are in good agreement with the experimental results,which indicates that the mathematical model is reliable and can be used to predict the flow field of the air-agitated seed precipitation tank.
基金supported by the Science Foundation of the Department of Health,Hubei Province,China (No.XF06D43,XF2008-23)
文摘Objective The present study aimed to establish a cerebral schistosomiasis model in rabbits,to provide a valuable tool for morphological analysis,clinical manifestation observation,as well as investigations into immunological reactions and pathogenesis of focal inflammatory reaction in neuroschistosomiasis（NS）.Methods Sixty New Zealand rabbits were randomly assigned into operation,sham-operation and normal groups.Rabbits in the operation group received direct injection of dead schistosome eggs into the brain,while their counterparts in the sham-operation group received saline injection.Rabbits in the normal group received no treatment.Base on the clinical manifestations,rabbits were sacrificed on days 3,5,7,10,20,and 30 post injection,and brain samples were sectioned and stained with hematoxylin-eosin.Sections were observed under the microscope.Results The rabbits in the operation group exhibited various neurological symptoms,including anorexy,partial and general seizures,and paralysis.The morphological analysis showed several schistosome eggs in the nervous tissue on day 3 post operation,with very mild inflammation.On days 7-10 post operation,several schistosome eggs were localized in proximity to red blood cells with many neutrophilic granulocytes and eosinophilic granulocytes around them.The schistosome eggs developed into the productive granuloma stage on days 14-20 post operation.On day 30,the schistosome eggs were found to be in the healing-by-fibrosis stage,and the granuloma area was replaced by fibrillary glia through astrocytosis.The sham-operation group and the normal group showed negative results.Conclusion This method might be used to establish the cerebral schistosomiasis experimental model.Several factors need to be considered in establishing this model,such as the antigenic property of eggs,the time of scarification,and the clinical manifestations.
文摘Wide angle acquisition has been taken as a significant measure to obtain high quality seismic data and is getting greater attention, In this paper, we discuss ocean bottom cable （OBC） seismic wide angle reflections on the basis of a layered model experiment. Some experiment results don＇t support theoretical conclusions. The main experimental conclusions are： 1. Wide angle reflection energies are stronger than non-wide-angle reflections （up to twice as strong） but there is a big difference between observations and theoretical calculations that suggest the wide angle reflection energies are 15 times the non- wide-angle reflection energy. The reflection energy increases gradually rather than sharply as the theoretical calculations suggest. 2. The reflection events remain hyperbolic when the offset increases. 3. Wide angle reflection dominant frequency is about 20-30% less than non- wide-angle reflections and decreases as the offset increases. The non-wide-angle reflection dominant frequency shows no obvious variation for small offsets. 4. There is no wave shape mutation or polarity reversal near the critical angle. 5. The reflection event group features are the same for both cases of incidence angle greater and less than the critical angle. 6. Direct arrivals, multiples, and water bottom refractions influence the wide angle reflections of the sea floor.
基金supported by the China Postdoctoral Science Foundation (no. 2020M670599)
文摘Inflammation is a common disease involved in the pathogenesis,complications,and sequelae of a large number of related diseases,and therefore considerable research has been directed toward developing anti-inflammatory drugs for the prevention and treatment of these diseases.Traditional Chinese medicine(TCM)has been used to treat inflammatory and related diseases since ancient times.According to the re-view of abundant modern scientific researches,it is suggested that TCM exhibit anti-inflammatory effects at different levels,and via multiple pathways with various targets,and recently a series of in vitro and in vivo anti-inflammatory models have been developed for anti-inflammation research in TCM.Currently,the reported classic mechanisms of TCM and experimental models of its anti-inflammatory effects pro-vide reference points and guidance for further research and development of TCM.Importantly,the research clearly confirms that TCM is now and will continue to be an effective form of treatment for many types of inflammation and inflammation-related diseases.
文摘Epilepsy is a common and serious neurological disease that causes recurrent seizures. The brain damage caused by seizures can lead to depression, anxiety, cognitive impairment, or disability. In almost all cases chronic seizures are difficult to cure. MicroRNAs are widely expressed in the central nervous system and play important roles in the pathogenesis of several neurological disorders, including epilepsy. A variety of animals(mostly mice and rats) have been used to induce experimental epilepsy using different protocols and miRNA profiling performed. Most of the recent studies reviewed had performed miRNA profiling in hippocampal tissues and a large number of microRNAs were dysregulated when compared to controls. Most notably, miR-132-3p,-146a-5p,-10a-5p,-21a-3p,-27a-3p,-142a-5p,-212-3p,-431-5p, and-155 were upregulated in both the mouse and rat studies. Overexpression of miR-137 and miR-219 decreased seizure severity in a mouse epileptic model, and suppression of miR-451,-10a-5p,-21a-5p,-27a-5p,-142a-5p,-431-5p,-155, and-134 had a positive influence on seizure behavior. In the rat studies, overexpression of miR-139-5p decreased neuronal damage in drug-resistant rats and inhibition of miR-129-2-3p,-27a-3p,-155,-134,-181a, and-146a had a positive effect on seizure behavior and/or reduced the loss of neuronal cells. Further studies are warranted using adult female and immature male and female animals. It would also be helpful to test the ability of specific agomirs and antagomirs to control seizure activity in a subhuman primate model of epilepsy such as adult marmosets injected intraperitoneally with pilocarpine or cynomolgus monkeys given intrahippocampal injections of kainic acid.
基金This research is financially supported by the National Natural Science Foundation of China(Nos.41807274,41630640)the Sichuan Science and Technology Program(No.2019E0R2230230)the Scientific Foundation of the Chinese Academy of Sciences(No.KFJ-STS-QYZD-172)。
文摘Using physical simulation models, rainfall-induced landslides have been simulated under various rainfall intensities. During these simulations, we have monitored the physical and mechanical behaviors of the landslide over the slip surface at different heights of the model slopes, as well as taking the whole slope to identify its deformation and failure processes. The results show that the rainfall duration corresponding to the initiation of the debris landslide and is exponentially related to rainfall intensity. Corresponding to the three intervals of the rainfall intensity, there are three types of slope failure modes:(1) the small-slump failure at the leading edge of the slope;(2) the block-slump failure but sometimes there are large blocks sliding down;and(3) the bulk failure but sometimes there is the block-slump failure. Based on the total rainfall-lasting time and the associated proportion of failed mass volume, the early warning of debris landslide can be classified into five grades, i.e., red, orange to red, orange, yellow to orange and yellow, which correspond to the five slope failure modes, respectively.
基金supported by the National Natural Science Foundation of China(No.11872212)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘To predict the flutter dynamic pressure of a wind tunnel model before flutter test,an accurate Computational Fluid Dynamics/Computational Structural Dynamics(CFD/CSD)-based flutter prediction method is proposed under the conditions of a 2.4 m×2.4 m transonic wind tunnel with porous wall.From the CFD simulations of the flows through an inclined hole of this wind tunnel,the Nambu's linear porous wall model between the flow rate and the differential pressure is extended to the porous wall with inclined holes,so that the porous wall can be conveniently modeled as a boundary condition.According to the flutter testing approach for the current wind tunnel,the steady CFD calculation is conducted to achieve the required inlet Mach number.A timedomain CFD/CSD method is then employed to evaluate the structural response of the experimental model,and the critical flutter point is obtained by increasing the dynamic pressure step by step at a fixed Mach number.The present method is applied to the flutter calculations for a vertical tail model and an aircraft model tested in the current transonic wind tunnel.For both models,the computed flutter characteristics agree well with the experimental results.
基金The Major National Science and Technology Programs of China under contract No.2011ZX05025-003-005the Joint Program of the National Science Foundation and Guangdong Province under contract No.U1301233
文摘Located at the northwest continental slope of the South China Sea, the Qiongdongnan Basin bears valley-shaped bathymetry deepening toward east. It is separated from the Yinggehai Basin through NW-trending Indo-China-Red River shear zone, and connected with NW subsea basin through the Xisha Trough. Along with the rapid progress of the deepwater exploration, large amounts of high resolution geophysical and geological data were accumulated. Scientific researches about deepwater basins kept revealing brand new tectonic and sedimentary discoveries. In order to summarize the structural features and main controlling factors of the deepwater Qiongdongnan Basin, a series of researches on basin architecture, fault activities, tectonic deformation and evolution were carried out. In reference to analogue modeling experiments, a tectonic situation and a basin formation mechanism were discussed. The researches indicate that：the northern boundary of the Qiongdongnan Basin is strongly controlled by No. 2 fault. The overlapping control of two stress fields from the east and the west made the central depression zone extremely thinned. Combined with the changed stress field, the segmentation of a preexisting weakness zone made the sags in the east experiencing different rifting histories from the west ones. The NE-trending west segment of the Qiongdongnan Basin experienced strong rifting during Eocene, while the roughly EW-trending sags in the east segment show strong rifting during late Eocene and early Oligocene. Local structures such as NW-trending basal fault and inherited uplifts controlled the lateral segmentation. So first order factors such as regional stress field and preexisting weakness zone controlled the basin zonation, while the second order factors determined the segmentation from east to west.
基金supported by the National Natural Science Foundation of China(81825011,81930038,81961160738)Program of Shanghai Academic/Technology Research Leader(22XD1400800)Strategic Priority Research Program of the Chinese Academy of Sciences(XDB19030200)。
文摘Viral infections have led to many public health crises and pandemics in the last few centuries.Neurotropic virus infection-induced viral encephalitis(VE),especially the symptomatic inflammation of the meninges and brain parenchyma,has attracted growing attention due to its high mortality and disability rates.Understanding the infectious routes of neurotropic viruses and the mechanism underlying the host immune response is critical to reduce viral spread and improve antiviral therapy outcomes.In this review,we summarize the common categories of neurotropic viruses,viral transmission routes in the body,host immune responses,and experimental animal models used for VE study to gain a deeper understanding of recent progress in the pathogenic and immunological mechanisms under neurotropic viral infection.This review should provide valuable resources and perspectives on how to cope with pandemic infections.
基金Project(50408020) supported by the National Natural Science Foundation of Chinaproject(05-0686) supported by the Program of New Century Excellent Talents in Universityproject(200550) supported by the Foundation for the Author of National Excellent Doctoral Dissertation of China
文摘To determine the ultimate bearing capacity of foundations on sloping ground surface in practice, energy dissipation method was used to formulate the beating capacity as programming problem, and full-scale model experiments were investigated to analyze the performance of the soil slopes loaded by a strip footing in laboratory. The soil failure is governed by a linear Mohr-Coulomb yield criterion, and soil deformation follows an associated flow rule. Based on the energy dissipation method of plastic mechanics, a multi-wedge translational failure mechanism was employed to obtain the three bearing capacity factors related to cohesion, equivalent surcharge load and the unit gravity for various slope inclination angles. Numerical results were compared with those of the published solutions using finite element method and those of model experiments. The bearing capacity factors were presented in the form of design charts for practical use in engineering. The results show that limit analysis solutions approximate to those of model tests, and that the energy dissipation method is effective to estimate bearing capacity of soil slope.
基金supported by the National Natural Science Foundation of China (No. 51174197)the Major State Basic Research Development Program of China (No. 2014CB046905)+1 种基金State Key Laboratory for Geo Mechanics and Deep Underground Engineering (CUMT) (No. SKLGDUEK1503)the ‘Qing Lan’ Project of Jiangsu Province
文摘A series of plane-strain physical model experiments are carried out to study the spatiotemporal evolution rule of rocks fracture surrounding gob-side roadway, which is subjected to the pressure induced by the mining process. The digital photogrammetry technology and large deformation analysis method are applied to measure the deformation and fracture of surrounding rocks. The experimental results indicate that the deformation and fracture of coal pillars are the cause to the instability and failure of the surrounding rocks. The spatiotemporal evolution rule of the rock deformation and fracture surrounding gob-side roadway is obtained. The coal pillar and the roof near coal pillar should be strengthened in support design. The engineering application results also can provide a useful guide that the combined support with wire meshes, beam, anchor bolt and cable is an effective method.
基金Supported by Xinjiang Key Lab of Xinjiang Science and Technology Bureau Xinjiang,No.2014KL002National Natural Science Foundation of China,No.81372425National S&T Major Project,No.SQ2018ZX100301
文摘AIM To investigate a safer way to set up the disease model of cystic echinococcosis without contamination risk and develop a novel experimental murine model of hepatic cystic echinococcosis. METHODS C57 B/6 mice were injected with human protoscolices of three different concentrations via the portal vein. The mice were followed for 10 mo by ultrasound,gross anatomy,and pathological and immunological examinations. The protoscolex migration in the portal vein,hydatid cyst growth,host immune reaction,and hepatic histopathology were examined periodically.RESULTS The infection rates in the mice in the high,medium,and low concentration groups were 90%,100%,and 63.6%,respectively. The protoscolices migrated in the portal vein with blood flow,settled in the liver,and developed into orthotopic hepatic hydatid cysts,resembling the natural infection route and course.CONCLUSION We have established an improved experimental model of hepatic cystic echinococcosis with low biohazard risk but stable growing dynamics and immune reaction. It is especially useful for new anti-parasite medication trials against hydatid disease.
基金supported by National Institutes of Health grants AI070827 and CA33266American Cancer Society grant RSG-09-076-01 and the UIC Walter Payton Center GUILD
文摘An estimated 130 million people worldwide are chronically infected with hepatitis C virus (HCV) making it a leading cause of liver disease worldwide. Because the currently available therapy of pegylated interferon-alpha and ribavirin is only effective in a subset of patients, the development of new HCV antivirals is a healthcare imperative. This review discusses the experimental models available for HCV antiviral drug research, recent advances in HCV antiviral drug development, as well as active research being pursued to facilitate development of new HCV-specific therapeutics.
