Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological damage.Hypoxic preconditioning has been shown to impr...Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological damage.Hypoxic preconditioning has been shown to improve migration and survival of bone marrow–derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest,but the specific mechanisms by which hypoxia-preconditioned bone marrow–derived mesenchymal stem cells protect against brain injury after cardiac arrest are unknown.To this end,we established an in vitro co-culture model of bone marrow–derived mesenchymal stem cells and oxygen–glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis,possibly through inhibition of the MAPK and nuclear factor κB pathways.Subsequently,we transplanted hypoxia-preconditioned bone marrow–derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by asphyxia.The results showed that hypoxia-preconditioned bone marrow–derived mesenchymal stem cells significantly reduced cardiac arrest–induced neuronal pyroptosis,oxidative stress,and mitochondrial damage,whereas knockdown of the liver isoform of phosphofructokinase in bone marrow–derived mesenchymal stem cells inhibited these effects.To conclude,hypoxia-preconditioned bone marrow–derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest,and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.展开更多
We sincerely thank the authors of the commentary1 for their thoughtful analysis and constructive critique of our systematic review on ischemic preconditioning(IPC)and placebo effects in exercise capacity and athletic ...We sincerely thank the authors of the commentary1 for their thoughtful analysis and constructive critique of our systematic review on ischemic preconditioning(IPC)and placebo effects in exercise capacity and athletic performance.2Their attention to methodological details,particularly concerning the inclusion and timing of warm-up protocols across studies,is commendable and contributes meaningfully to the ongoing refinement of IPC research in sports science.展开更多
We highly commend Dr Souza et al.1for their systematic review research.The authors conducted a detailed investigation into the effects of ischemic preconditioning(IPC)on athletic performance,comparing it with placebo ...We highly commend Dr Souza et al.1for their systematic review research.The authors conducted a detailed investigation into the effects of ischemic preconditioning(IPC)on athletic performance,comparing it with placebo and no-intervention conditions.The study found that while IPC demonstrated superior effects over the no-intervention group in certain metrics(e.g.,time to exhaustion),its performance did not significantly surpass that of the placebo group.This suggests that the potential benefits of IPC may partially stem from participants’psychological expectations,or placebo effects.The study also highlighted the significant impact of placebo interventions on athletic performance,emphasizing the importance of distinguishing between placebo and no-intervention conditions in experimental designs.展开更多
Objective Stroke is a main cause of disability and mortality worldwide.It has been reported that ischemic preconditioning(IP)has neuroprotective effects against stroke.This study aimed to verify the mechanism by which...Objective Stroke is a main cause of disability and mortality worldwide.It has been reported that ischemic preconditioning(IP)has neuroprotective effects against stroke.This study aimed to verify the mechanism by which calcium-sensing recep-tor(Casr)inhibition-mediated M2 microglial transformation in the IP protects against stroke,which will provide a potential therapeutic target for stroke.Methods Middle cerebral artery occlusion(MCAO)rats and oxygen-glucose deprivation(OGD)neurons were used in this study.IP was induced via the transient MCAO and OGD methods.RNA sequencing(RNA-Seq)was used to explore the underlying key molecules.Western blotting and immunohistochemistry were performed to detect the expression of Casr and the M1 and M2 microglial markers.CCK8 was used to detect cell viability.The calcium concentration was detected via the use of Fluo-4 AM,a fluorescence probe.The Casr inhibitor NPS2143 and the Casr activator R568 were used to explore the role of Casr in M2 microglial transformation and neuroprotection.Results We first revealed that IP induced M2 microglial transformation in ischemic injury.In addition,MCAO injury increased Casr expression and the calcium concentration,which was inhibited by IP.Furthermore,Casr activation inhibited the M2 microglial transformation induced by IP.Finally,we found that Casr inhibition improved the survival rate,alleviated neurological deficits,and reduced the infarct volume induced by MCAO.Conclusions We confirmed that Casr-related neuroprotection induced by IP is associated with the transformation of M2 microglia.These findings can be used to understand the protective mechanisms of IP against ischemic stroke.展开更多
Mesenchymal stem cells(MSCs)possess unique properties such as immunomodu-lation,paracrine actions,multilineage differentiation,and self-renewal.Therefore,MSC-based cell therapy is an innovative approach to treating va...Mesenchymal stem cells(MSCs)possess unique properties such as immunomodu-lation,paracrine actions,multilineage differentiation,and self-renewal.Therefore,MSC-based cell therapy is an innovative approach to treating various degenera-tive illnesses,including cardiovascular diseases.However,several challenges,including low transplant survival rates,low migration to the ischemic myocar-dium,and poor tissue retention,restrict the application of MSCs in clinical settings.These undesirable cell therapy outcomes mainly originated due to the overproduction of reactive oxygen species(ROS)in the injured heart.MSCs'stress-coping capacity can be enhanced by preconditioning them under conditions similar to the microenvironment of wounded tissues.Hydrogen peroxide(H_(2)O_(2))is a ROS that has been shown to activate protective cellular mechanisms such as survival,proliferation,migration,paracrine effects,and differentiation at suble-thal doses.These processes are induced via phosphatidylinositol 3-kinase/protein kinase B,p38 mitogen-activated protein kinases,c-Jun N-terminal kinase,Janus kinase/signal transducer and activator of the transcription,Notch1,and Wnt sig-naling pathways.H_(2)O_(2) preconditioning could lead to many clinical benefits,including ischemic injury reduction,enhanced survival of cellular transplants,and tissue regeneration.In this review,we present an overview of stem cell preconditioning methods and the biological functions activated by H_(2)O_(2) precondi-tioning.Furthermore,this review explores the molecular mechanisms underlying the protective cellular functions stimulated under H_(2)O_(2) preconditioning.展开更多
Based on waveform fitting,full waveform inversion(FWI)is an important inversion method with the ability to reconstruct multi-parameter models in high precision.However,the strong nonlinear equation used in FWI present...Based on waveform fitting,full waveform inversion(FWI)is an important inversion method with the ability to reconstruct multi-parameter models in high precision.However,the strong nonlinear equation used in FWI presents the following challenges,such as low convergence efficiency,high dependence on the initial model,and the energy imbalance in deep region of the inverted model.To solve these inherent problems,we develop a timedomain elastic FWI method based on gradient preconditioning with the following details:(1)the limited memory Broyden Fletcher Goldfarb Shanno method with faster convergence is adopted to im-prove the inversion stability;(2)a multi-scaled inversion strategy is used to alleviate the nonlinear inversion instead of falling into the local minimum;(3)in addition,the pseudo-Hessian preconditioned illumination operator is involved for preconditioning the parameter gradients to improve the illumination equilibrium degree of deep structures.Based on the programming implementation of the new method,a deep depression model with five diffractors is used for testing.Compared with the conventional elastic FWI method,the technique proposed by this study has better effectiveness and accuracy on the inversion effect and con-vergence,respectively.展开更多
In this editorial,we comment on the article published in the recent issue of the World Journal of Stem Cells.They focus on stem cell preconditioning to prevent ferroptosis by modulating the cystathionineγ-lyase/hydro...In this editorial,we comment on the article published in the recent issue of the World Journal of Stem Cells.They focus on stem cell preconditioning to prevent ferroptosis by modulating the cystathionineγ-lyase/hydrogen sulfide(H_(2)S)pathway as a novel approach to treat vascular disorders,particularly pulmonary hypertension.Preconditioned stem cells are gaining popularity in regenerative medicine due to their unique ability to survive by resisting the harsh,unfavorable microenvironment of the injured tissue.They also secrete various paracrine factors against apoptosis,necrosis,and ferroptosis to enhance cell survival.Ferroptosis,a regulated form of cell death characterized by iron accumulation and oxidative stress,has been implicated in various pathologies encompassing dege-nerative disorders to cancer.The lipid peroxidation cascade initiates and sustains ferroptosis,generating many reactive oxygen species that attack and damage multiple cellular structures.Understanding these intertwined mechanisms provi-des significant insights into developing therapeutic modalities for ferroptosis-related diseases.This editorial primarily discusses stem cell preconditioning in modulating ferroptosis,focusing on the cystathionase gamma/H_(2)S ferroptosis pathway.Ferroptosis presents a significant challenge in mesenchymal stem cell(MSC)-based therapies;hence,the emerging role of H_(2)S/cystathionase gamma/H_(2) S signaling in abrogating ferroptosis provides a novel option for therapeutic intervention.Further research into understanding the precise mechanisms of H_(2)S-mediated cytoprotection against ferroptosis is warranted to enhance the thera-peutic potential of MSCs in clinical settings,particularly vascular disorders.展开更多
Spinal cord injury is a disabling condition with limited treatment options.Multiple studies have provided evidence suggesting that small extracellular vesicles(SEVs)secreted by bone marrow mesenchymal stem cells(MSCs)...Spinal cord injury is a disabling condition with limited treatment options.Multiple studies have provided evidence suggesting that small extracellular vesicles(SEVs)secreted by bone marrow mesenchymal stem cells(MSCs)help mediate the beneficial effects conferred by MSC transplantation following spinal cord injury.Strikingly,hypoxia-preconditioned bone marrow mesenchymal stem cell-derived SEVs(HSEVs)exhibit increased therapeutic potency.We thus explored the role of HSEVs in macrophage immune regulation after spinal cord injury in rats and their significance in spinal cord repair.SEVs or HSEVs were isolated from bone marrow MSC supernatants by density gradient ultracentrifugation.HSEV administration to rats via tail vein injection after spinal cord injury reduced the lesion area and attenuated spinal cord inflammation.HSEVs regulate macrophage polarization towards the M2 phenotype in vivo and in vitro.Micro RNA sequencing and bioinformatics analyses of SEVs and HSEVs revealed that mi R-146a-5p is a potent mediator of macrophage polarization that targets interleukin-1 receptor-associated kinase 1.Reducing mi R-146a-5p expression in HSEVs partially attenuated macrophage polarization.Our data suggest that HSEVs attenuate spinal cord inflammation and injury in rats by transporting mi R-146a-5p,which alters macrophage polarization.This study provides new insights into the application of HSEVs as a therapeutic tool for spinal cord injury.展开更多
Mesenchymal stem/stromal cells are potential optimal cell sources for stem cell therapies,and pretreatment has proven to enhance cell vitality and function.In a recent publication,Li et al explored a new combination o...Mesenchymal stem/stromal cells are potential optimal cell sources for stem cell therapies,and pretreatment has proven to enhance cell vitality and function.In a recent publication,Li et al explored a new combination of pretreatment condi-tions.Here,we present an editorial to comment on their work and provide our view on mesenchymal stem/stromal cell precondition.展开更多
The implicit partition algorithm used to solve fluid–structure coupling problems has high accuracy,but it requires a long computation time.In this paper,a semi-implicit fluid–structure coupling algorithm based on mo...The implicit partition algorithm used to solve fluid–structure coupling problems has high accuracy,but it requires a long computation time.In this paper,a semi-implicit fluid–structure coupling algorithm based on modal force prediction-correction is proposed to improve the computational efficiency.In the pre-processing stage,the fluid domain is assumed to be a pseudo-elastic solid and merged with the solid domain to form a holistic system,and the normalized modal information of the holistic system is calculated and stored.During the sub-step cycle,the modal superposition method is used to obtain the response of the holistic system with the predicted modal force as the load,so that the deformation of the structure and the updating of the fluid mesh can be achieved simultaneously.After solving the Reynolds-averaged Navier-Stokes equations in the fluid domain,the predicted modal force is corrected and a new sub-step cycle is started until the converged result is obtained.In this method,the computation of the fluid equations and the updating of the dynamic mesh are done implicitly,while the deformation of the structure is done explicitly.Two numerical cases,vortex induced oscillation of an elastic beam and fluid–structure interaction of a final stage blade,are used to verify the efficiency and accuracy of the proposed algorithm.The results show that the proposed method achieves the same accuracy as the implicit method while the computational time is reduced.In the case of the vortex-induced oscillation problem,the computational time can be reduced to 18.6%.In the case of the final stage blade vibration,the computational time can be reduced to 53.8%.展开更多
In seismic data processing, blind deconvolution is a key technology. Introduced in this paper is a flow of one kind of blind deconvolution. The optimal precondition conjugate gradients (PCG) in Kyrlov subspace is als...In seismic data processing, blind deconvolution is a key technology. Introduced in this paper is a flow of one kind of blind deconvolution. The optimal precondition conjugate gradients (PCG) in Kyrlov subspace is also used to improve the stability of the algorithm. The computation amount is greatly decreased.展开更多
Objective To investigate the effect of ischemic preconditioning on chaperone hsp70 expression and protein aggregation in the CA1 neurons of rats, and to further explore its potential neuroprotective mechanism. Methods...Objective To investigate the effect of ischemic preconditioning on chaperone hsp70 expression and protein aggregation in the CA1 neurons of rats, and to further explore its potential neuroprotective mechanism. Methods Two-vesseloccluded transient global ischemia rat model was used. The rats were divided into sublethal 3-min ischemia group, lethal 10- min ischemia group and ischemic preconditioning group. Neuronal death in the CA1 region was observed by hematoxylineosin staining, and number of live neurons was assessed by cell counting under a light microscope. Immunochemistry and laser scanning confocal microscopy were used to observe the distribution of chaperone hsp70 in the CA1 neurons. Differential centrifuge was used to isolate cytosol, nucleus and protein aggregates fractions. Western blot was used to analyze the quantitative alterations of protein aggregates and inducible chaperone hsp70 in cellular fractions and in protein aggregates under different ischemic conditions. Results Histological examination showed that ischemic preconditioning significantly reduced delayed neuronal death in the hippocampus CA1 region （P 〈 0.01 vs 10-min ischemia group）. Sublethal ischemic preconditioning induced chaperone hsp70 expression in the CA1 neurons after 24 h reperfusion following 10-min ischemia. Induced-hsp70 combined with the abnormal proteins produced during the secondary lethal 10-min ischemia and inhibited the formation of cytotoxic protein aggregates（P〈0.01 vs 10-min ischemia group）.Conelusion Ischemic preconditioning induced chaperone hsp70 expression and inhibited protein aggregates formation in the CA1 neurons when suffered secondary lethal ischemia, which may protect neurons from death.展开更多
In order to solve the problem that the current matchmaking methods for semantic web service mainly focus on the matchmaking of IO （inputs, outputs） descriptions which may result in one-sidedness, a description-logic...In order to solve the problem that the current matchmaking methods for semantic web service mainly focus on the matchmaking of IO （inputs, outputs） descriptions which may result in one-sidedness, a description-logic-based IOPE （inputs, outputs, preconditions, effects） description and matchmaking method is proposed for semantic web service. The description logic concept is used to annotate service IO and the description logic assertion is employed to describe service PE（preconditions, effects）. TBox subsumption checking is used to measure the subsumption relationship between IO descriptions of service request and advertising; ABox consistency checking is used for checking the logical implication between PE descriptions of service request and advertising. Based upon the logical implication, four kinds of PE matching degrees are proposed to measure and compare the pros and cons of the results of matchmaking. They are the exact, perfect, side-effect and common match. Experiments show that the method has a higher precision rate under the same recall rate compared with the existing method.展开更多
Objective Sevoflurane preconditioning has been demonstrated to reduce cerebral ischemia–reperfusion（IR） injury,but the underlying mechanisms have not been fully elucidated.Besides,different protocols would usually ...Objective Sevoflurane preconditioning has been demonstrated to reduce cerebral ischemia–reperfusion（IR） injury,but the underlying mechanisms have not been fully elucidated.Besides,different protocols would usually lead to different results.The objective of this study was to determine whether dual exposure to sevoflurane improves the effect of anesthetic preconditioning against oxygen and glucose deprivation（OGD）injury in vitro.Methods Rat hippocampal slices under normoxic conditions（95%O2/5%CO2）were pre-exposed to sevoflurane 1,2 and 3 minimum alveolar concentration （MAC）for 30 min,once or twice,with 15-min washout after each exposure.The slices were then subjected to 13-min OGD treatment（95%N2/5%CO2,glucose-free）,followed by 30-min reoxygenation.The population spikes（PSs）were recorded in the CA1 region of rat hippocampus.The percentage of PS amplitude at the end of 30-min reoxygenation to that before OGD treatment was calculated,since it could indicate the recovery degree of neuronal function.In addition,to assess the role of mitogen-activated protein kinases（MAPKs）in preconditioning,U0126,an inhibitor of extracellular signal–regulated protein kinase（MEK-ERK1/2,ERK1/2 MAPK）,and SB203580,an inhibitor of p38 MAPK,were separately added 10 min before sevoflurane exposure.Results Preconditioning once with sevoflurane 1,2,and 3 MAC increased the percentage of PS amplitude at the end of 30-min reoxygenation to that before OGD treatment,from（15.13±3.79）%（control）to（31.88±5.36）%, （44.00±5.01）%,and（49.50±6.25）%,respectively,and twice preconditioning with sevoflurane 1,2,and 3 MAC increased the percentage to（38.53±4.36）%,（50.74±7.05）%and（55.86±6.23）%,respectively.The effect of duplicate preconditioning with sevoflurane 3 MAC was blocked by U0126[（16.23±4.62）%].Conclusion Sevoflurane preconditioning can induce neuroprotection against OGD injury in vitro,and preconditioning twice enhances this effect.Besides,the activation of extracellular signal–regulated protein kinase（MEK-ERK1/2,ERK1/2 MAPK）may be involved in this process.展开更多
Objective To investigate whether desferoxamine （DFO） preconditioning can induce tolerance against cerebral ischemia and its effect on the expression of hypoxia inducible factor 1 α （HIF- 1α） and erythropoietin ...Objective To investigate whether desferoxamine （DFO） preconditioning can induce tolerance against cerebral ischemia and its effect on the expression of hypoxia inducible factor 1 α （HIF- 1α） and erythropoietin （EPO） in vivo and in vitro. Methods Rat model of cerebral ischemia was established by middle cerebral artery occlusion with or without DFO administration. Infarct size was examined by TTC staining, and the neurological severity score was evaluated according to published method. Cortical neurons were cultured under ischemia stress which was mimicked by oxygen-glucose deprivation （OGD）, and the neuron damage was assessed by MTT assay. Immunofluorescent staining was employed to detect the expressions of HIF-1 and EPO. Results The protective effect induced by DFO （decreasing the infarction volume and ameliorating the neurological function） appeared at 2 d after administration ofDFO （post-DFO）, lasted until 7 d and disappeared at 14 d （P 〈 0.05）; the most effective action was observed at 3 d post-DFO. DFO induced tolerance of cultured neurons against OGD： neuronal viability was increased 23%, 34%, 40%, 48% and 56% at 8 h, 12 h, 24 h, 36 h, and 48 h, respectively, post-DFO （P 〈 0.05）. Immunofluorescent staining found that HIF-1 α and EPO were upregulated in the neurons of rat brain at 3 d and 7 d post-DFO; increase of HIF-1 α and EPO appeared in cultured cortex neurons at 36 h and 48 h post-DFO. Conclusion DFO induced tolerance against focal cerebral ischemia in rats, and exerted protective effect on OGD cultured cortical neurons. DFO significant induced the expression of HIF- 1 α and EPO both in vivo and in vitro. DFO preconditioning can protect against cerebral ischemia, which may be associated with the synthesis of HIF- 1 α and EPO.展开更多
The preconditioning method is used to solve the low Mach number flow. The space discritisation scheme is the Roe scheme and the DES turbulence model is used. Then, the low Mach number turbulence flow around the NACA00...The preconditioning method is used to solve the low Mach number flow. The space discritisation scheme is the Roe scheme and the DES turbulence model is used. Then, the low Mach number turbulence flow around the NACA0012 airfoil is used to verify the efficiency of the proposed method. Two cases of the low Mach number flows around the multi-element airfoil and the circular cylinder are also used to test the proposed method. Numerical results show that the methods combined the preconditioning method and compressible Navier-Stokes equations are efficient to solve low Mach number flows.展开更多
Objective To investigate the protective effects of hydrogen peroxide preconditioning （HPP） on the pheochromocytoma （PC12） cells treated with 1-methyl-4-phenylpyridinium （MPP^＋） and to explore the potential mech...Objective To investigate the protective effects of hydrogen peroxide preconditioning （HPP） on the pheochromocytoma （PC12） cells treated with 1-methyl-4-phenylpyridinium （MPP^＋） and to explore the potential mechanisms. Methods The viability and apoptosis of PC 12 cells were determinded by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay and 4′,6′-diamidino-2-phenylindole （DAPI） staining, respectively. The expressions of 14-3-3 protein and phospholylated p38 mitogen-activated protein kinase （MAPK） were determined by Western blot. Enzyme-linked immunosorbent assay （ELISA） was used to measure the activity of extracellular signal-regulated protein kinase 1/2 （ERK1/2）. Results The cell viability decreased and the number of apoptotic cells increased dramatically in MPP^＋ group compared with that in Control group. HPP induced a significant increase in cell viability and a marked decrease in population of apoptotic cells of the MPP^＋- treated PC 12 cells, accompanied with up-regulation of 14-3-3 protein and increase of ERK 1/2 and p38 MAPK activities. The 14-3-3 protein expression was positively correlated with the phosphorylation of ERK1/2. Furthermore, inhibition of the ERK1/2 with PD98059 abolished the 14-3-3 protein up-regulation in PC 12 cells induced by HPP. Conclusion HPP protects PC 12 cells against MPP＋ toxicity by up-regulating 14-3-3 protein expression through the ERK1/2 and p38 MAPK signaling pathways.展开更多
Objective To identify the protective effect of lipopolysaccharide （LPS） preconditioning against LPS-induced inflammatory damage in dopaminergic neurons of midbrain slice culture and the possible mechanisms. Methods ...Objective To identify the protective effect of lipopolysaccharide （LPS） preconditioning against LPS-induced inflammatory damage in dopaminergic neurons of midbrain slice culture and the possible mechanisms. Methods After cultured in vitro for 14 d, the rat organotypic midbrain slices were pretreated with different concentrations （0, 1, 3, 6 or 10 ng/mL） of LPS for 24 h followed by treatment with 100 ng/mL LPS for 72 h. The whole slice viability was detelmined by measurement of the activity of lactic acid dehydrogenase （LDH）. Tyrosine hydroxylase-immunoreactive （TH-IR） neurons and CD 1 1 b/c equivalent-immunoreactive （OX-42-IR） microglia in the slices were observed by immunohistochemical method, and tumor necrosis factor-α （TNF-α levels in the culture media were detected by enzymelinked immunosorbent assays （ELISA）. Results In the slices treated with 100 ng/mL LPS for 72 h, the number of TH-IR neurons reduced from 191± 12 in the control slices to 46±4, and the LDH activity elevated obviously （P 〈 0.01）, along with remarkably increased number of OX-42-IR cells and production of TNF-α （P 〈 0.01）. Preconditioning with 3 or 6 ng/mL LPS attenuated neuron loss （the number of TH-IR neurons increased to 126± 12 and 180± 13, respectively） and markedly reduced LDH levels （P 〈 0.05）, accompanied by significant decreases of OX-42-IR microglia activation and TNF-α production （P 〈 0.05）. Conclusion Low-dose LPS preconditioning could protect dopaminergic neurons against inflammatory damage in rat midbrain slice culture, and inhibition of microglial activation and reduction of the proinflammatory factor TNF-α production may contribute to this protective effect. Further understanding the underlying mechanism of LPS preconditioning may open a new window for treatment of Parkinson＇s disease.展开更多
A new favorable iterative algorithm named as PBiCGSTAB （preconditioned bi-conjugate gradient stabilized） algorithm is presented for solving large sparse complex systems. Based on the orthogonal list, the special tec...A new favorable iterative algorithm named as PBiCGSTAB （preconditioned bi-conjugate gradient stabilized） algorithm is presented for solving large sparse complex systems. Based on the orthogonal list, the special technique of only storing non-zero elements is carried out. The incomplete LU factorization without fill-ins is adopted to reduce the condition number of the coefficient matrix. The BiCGSTAB algorithm is extended from the real system to the complex system and it is used to solve the preconditioned complex linear equations. The locked-rotor state of a single-sided linear induction machine is simulated by the software programmed with the finite element method and the PBiCGSTAB algorithm. Then the results are compared with those from the commercial software ANSYS, showing the validation of the proposed software. The iterative steps required for the proposed algorithm are reduced to about one-third, when compared to the BiCG method, therefore the algorithm is fast.展开更多
The present study established a model of brain ischemia in aged rats using four-vessel occlusion.We observed hippocampal CA1 neuronal apoptosis and apoptosis-mediated protease caspase-3 expression following preconditi...The present study established a model of brain ischemia in aged rats using four-vessel occlusion.We observed hippocampal CA1 neuronal apoptosis and apoptosis-mediated protease caspase-3 expression following preconditioning of electroacupuncture at Baihui（GV 20）.Our results showed that the number of hippocampal CA1 normal neurons was decreased,and degenerated neurons were increased 12 hours to 3 days following cerebral ischemia/reperfusion.The number of hippocampal CA1 apoptotic neurons and caspase-3-positive neurons in rats with cerebral ischemia/reperfusion injury was significantly decreased following acupuncture preconditioning.Acupuncture preconditioning protects aged rats against ischemia/reperfusion injury by regulating caspase-3 protein expression.展开更多
基金supported by the Natural Science Fund of Fujian Province,No.2020J011058(to JK)the Project of Fujian Provincial Hospital for High-level Hospital Construction,No.2020HSJJ12(to JK)+1 种基金the Fujian Provincial Finance Department Special Fund,No.(2021)848(to FC)the Fujian Provincial Major Scientific and Technological Special Projects on Health,No.2022ZD01008(to FC).
文摘Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological damage.Hypoxic preconditioning has been shown to improve migration and survival of bone marrow–derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest,but the specific mechanisms by which hypoxia-preconditioned bone marrow–derived mesenchymal stem cells protect against brain injury after cardiac arrest are unknown.To this end,we established an in vitro co-culture model of bone marrow–derived mesenchymal stem cells and oxygen–glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis,possibly through inhibition of the MAPK and nuclear factor κB pathways.Subsequently,we transplanted hypoxia-preconditioned bone marrow–derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by asphyxia.The results showed that hypoxia-preconditioned bone marrow–derived mesenchymal stem cells significantly reduced cardiac arrest–induced neuronal pyroptosis,oxidative stress,and mitochondrial damage,whereas knockdown of the liver isoform of phosphofructokinase in bone marrow–derived mesenchymal stem cells inhibited these effects.To conclude,hypoxia-preconditioned bone marrow–derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest,and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.
文摘We sincerely thank the authors of the commentary1 for their thoughtful analysis and constructive critique of our systematic review on ischemic preconditioning(IPC)and placebo effects in exercise capacity and athletic performance.2Their attention to methodological details,particularly concerning the inclusion and timing of warm-up protocols across studies,is commendable and contributes meaningfully to the ongoing refinement of IPC research in sports science.
文摘We highly commend Dr Souza et al.1for their systematic review research.The authors conducted a detailed investigation into the effects of ischemic preconditioning(IPC)on athletic performance,comparing it with placebo and no-intervention conditions.The study found that while IPC demonstrated superior effects over the no-intervention group in certain metrics(e.g.,time to exhaustion),its performance did not significantly surpass that of the placebo group.This suggests that the potential benefits of IPC may partially stem from participants’psychological expectations,or placebo effects.The study also highlighted the significant impact of placebo interventions on athletic performance,emphasizing the importance of distinguishing between placebo and no-intervention conditions in experimental designs.
基金supported by the National Natural Science Foundation of China(grant numbers 81371440,82271454 and 81971195).
文摘Objective Stroke is a main cause of disability and mortality worldwide.It has been reported that ischemic preconditioning(IP)has neuroprotective effects against stroke.This study aimed to verify the mechanism by which calcium-sensing recep-tor(Casr)inhibition-mediated M2 microglial transformation in the IP protects against stroke,which will provide a potential therapeutic target for stroke.Methods Middle cerebral artery occlusion(MCAO)rats and oxygen-glucose deprivation(OGD)neurons were used in this study.IP was induced via the transient MCAO and OGD methods.RNA sequencing(RNA-Seq)was used to explore the underlying key molecules.Western blotting and immunohistochemistry were performed to detect the expression of Casr and the M1 and M2 microglial markers.CCK8 was used to detect cell viability.The calcium concentration was detected via the use of Fluo-4 AM,a fluorescence probe.The Casr inhibitor NPS2143 and the Casr activator R568 were used to explore the role of Casr in M2 microglial transformation and neuroprotection.Results We first revealed that IP induced M2 microglial transformation in ischemic injury.In addition,MCAO injury increased Casr expression and the calcium concentration,which was inhibited by IP.Furthermore,Casr activation inhibited the M2 microglial transformation induced by IP.Finally,we found that Casr inhibition improved the survival rate,alleviated neurological deficits,and reduced the infarct volume induced by MCAO.Conclusions We confirmed that Casr-related neuroprotection induced by IP is associated with the transformation of M2 microglia.These findings can be used to understand the protective mechanisms of IP against ischemic stroke.
文摘Mesenchymal stem cells(MSCs)possess unique properties such as immunomodu-lation,paracrine actions,multilineage differentiation,and self-renewal.Therefore,MSC-based cell therapy is an innovative approach to treating various degenera-tive illnesses,including cardiovascular diseases.However,several challenges,including low transplant survival rates,low migration to the ischemic myocar-dium,and poor tissue retention,restrict the application of MSCs in clinical settings.These undesirable cell therapy outcomes mainly originated due to the overproduction of reactive oxygen species(ROS)in the injured heart.MSCs'stress-coping capacity can be enhanced by preconditioning them under conditions similar to the microenvironment of wounded tissues.Hydrogen peroxide(H_(2)O_(2))is a ROS that has been shown to activate protective cellular mechanisms such as survival,proliferation,migration,paracrine effects,and differentiation at suble-thal doses.These processes are induced via phosphatidylinositol 3-kinase/protein kinase B,p38 mitogen-activated protein kinases,c-Jun N-terminal kinase,Janus kinase/signal transducer and activator of the transcription,Notch1,and Wnt sig-naling pathways.H_(2)O_(2) preconditioning could lead to many clinical benefits,including ischemic injury reduction,enhanced survival of cellular transplants,and tissue regeneration.In this review,we present an overview of stem cell preconditioning methods and the biological functions activated by H_(2)O_(2) precondi-tioning.Furthermore,this review explores the molecular mechanisms underlying the protective cellular functions stimulated under H_(2)O_(2) preconditioning.
基金supported by the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(Grant No.2021QNLM020001)the National Key R&D Program of China(Grant No.2019YFC0605503C)+2 种基金the Major Scientific and Technological Projects of China National Petroleum Corporation(CNPC)(Grant No.ZD2019-183-003)the National Outstanding Youth Science Foundation(Grant No.41922028)the National Innovation Group Project(Grant No.41821002).
文摘Based on waveform fitting,full waveform inversion(FWI)is an important inversion method with the ability to reconstruct multi-parameter models in high precision.However,the strong nonlinear equation used in FWI presents the following challenges,such as low convergence efficiency,high dependence on the initial model,and the energy imbalance in deep region of the inverted model.To solve these inherent problems,we develop a timedomain elastic FWI method based on gradient preconditioning with the following details:(1)the limited memory Broyden Fletcher Goldfarb Shanno method with faster convergence is adopted to im-prove the inversion stability;(2)a multi-scaled inversion strategy is used to alleviate the nonlinear inversion instead of falling into the local minimum;(3)in addition,the pseudo-Hessian preconditioned illumination operator is involved for preconditioning the parameter gradients to improve the illumination equilibrium degree of deep structures.Based on the programming implementation of the new method,a deep depression model with five diffractors is used for testing.Compared with the conventional elastic FWI method,the technique proposed by this study has better effectiveness and accuracy on the inversion effect and con-vergence,respectively.
文摘In this editorial,we comment on the article published in the recent issue of the World Journal of Stem Cells.They focus on stem cell preconditioning to prevent ferroptosis by modulating the cystathionineγ-lyase/hydrogen sulfide(H_(2)S)pathway as a novel approach to treat vascular disorders,particularly pulmonary hypertension.Preconditioned stem cells are gaining popularity in regenerative medicine due to their unique ability to survive by resisting the harsh,unfavorable microenvironment of the injured tissue.They also secrete various paracrine factors against apoptosis,necrosis,and ferroptosis to enhance cell survival.Ferroptosis,a regulated form of cell death characterized by iron accumulation and oxidative stress,has been implicated in various pathologies encompassing dege-nerative disorders to cancer.The lipid peroxidation cascade initiates and sustains ferroptosis,generating many reactive oxygen species that attack and damage multiple cellular structures.Understanding these intertwined mechanisms provi-des significant insights into developing therapeutic modalities for ferroptosis-related diseases.This editorial primarily discusses stem cell preconditioning in modulating ferroptosis,focusing on the cystathionase gamma/H_(2)S ferroptosis pathway.Ferroptosis presents a significant challenge in mesenchymal stem cell(MSC)-based therapies;hence,the emerging role of H_(2)S/cystathionase gamma/H_(2) S signaling in abrogating ferroptosis provides a novel option for therapeutic intervention.Further research into understanding the precise mechanisms of H_(2)S-mediated cytoprotection against ferroptosis is warranted to enhance the thera-peutic potential of MSCs in clinical settings,particularly vascular disorders.
基金supported by the Fujian Minimally Invasive Medical Center Foundation,No.2128100514(to CC,CW,HX)the Natural Science Foundation of Fujian Province,No.2023J01640(to CC,CW,ZL,HX)。
文摘Spinal cord injury is a disabling condition with limited treatment options.Multiple studies have provided evidence suggesting that small extracellular vesicles(SEVs)secreted by bone marrow mesenchymal stem cells(MSCs)help mediate the beneficial effects conferred by MSC transplantation following spinal cord injury.Strikingly,hypoxia-preconditioned bone marrow mesenchymal stem cell-derived SEVs(HSEVs)exhibit increased therapeutic potency.We thus explored the role of HSEVs in macrophage immune regulation after spinal cord injury in rats and their significance in spinal cord repair.SEVs or HSEVs were isolated from bone marrow MSC supernatants by density gradient ultracentrifugation.HSEV administration to rats via tail vein injection after spinal cord injury reduced the lesion area and attenuated spinal cord inflammation.HSEVs regulate macrophage polarization towards the M2 phenotype in vivo and in vitro.Micro RNA sequencing and bioinformatics analyses of SEVs and HSEVs revealed that mi R-146a-5p is a potent mediator of macrophage polarization that targets interleukin-1 receptor-associated kinase 1.Reducing mi R-146a-5p expression in HSEVs partially attenuated macrophage polarization.Our data suggest that HSEVs attenuate spinal cord inflammation and injury in rats by transporting mi R-146a-5p,which alters macrophage polarization.This study provides new insights into the application of HSEVs as a therapeutic tool for spinal cord injury.
文摘Mesenchymal stem/stromal cells are potential optimal cell sources for stem cell therapies,and pretreatment has proven to enhance cell vitality and function.In a recent publication,Li et al explored a new combination of pretreatment condi-tions.Here,we present an editorial to comment on their work and provide our view on mesenchymal stem/stromal cell precondition.
基金support of the National Natural Science Foundation of China(No.51675406)the Basic Research Project Group,China(No.514010106-205)。
文摘The implicit partition algorithm used to solve fluid–structure coupling problems has high accuracy,but it requires a long computation time.In this paper,a semi-implicit fluid–structure coupling algorithm based on modal force prediction-correction is proposed to improve the computational efficiency.In the pre-processing stage,the fluid domain is assumed to be a pseudo-elastic solid and merged with the solid domain to form a holistic system,and the normalized modal information of the holistic system is calculated and stored.During the sub-step cycle,the modal superposition method is used to obtain the response of the holistic system with the predicted modal force as the load,so that the deformation of the structure and the updating of the fluid mesh can be achieved simultaneously.After solving the Reynolds-averaged Navier-Stokes equations in the fluid domain,the predicted modal force is corrected and a new sub-step cycle is started until the converged result is obtained.In this method,the computation of the fluid equations and the updating of the dynamic mesh are done implicitly,while the deformation of the structure is done explicitly.Two numerical cases,vortex induced oscillation of an elastic beam and fluid–structure interaction of a final stage blade,are used to verify the efficiency and accuracy of the proposed algorithm.The results show that the proposed method achieves the same accuracy as the implicit method while the computational time is reduced.In the case of the vortex-induced oscillation problem,the computational time can be reduced to 18.6%.In the case of the final stage blade vibration,the computational time can be reduced to 53.8%.
基金With the support of the key project of Knowledge Innovation, CAS(KZCX1-y01, KZCX-SW-18), Fund of the China National Natural Sciences and the Daqing Oilfield with Grant No. 49894190
文摘In seismic data processing, blind deconvolution is a key technology. Introduced in this paper is a flow of one kind of blind deconvolution. The optimal precondition conjugate gradients (PCG) in Kyrlov subspace is also used to improve the stability of the algorithm. The computation amount is greatly decreased.
基金the grants from the Department of Science and Technology of Jilin Province, China (No. 20070721)the Bureau of Science and Technology of Changchun, Jilin Province, China (No. 2007129).
文摘Objective To investigate the effect of ischemic preconditioning on chaperone hsp70 expression and protein aggregation in the CA1 neurons of rats, and to further explore its potential neuroprotective mechanism. Methods Two-vesseloccluded transient global ischemia rat model was used. The rats were divided into sublethal 3-min ischemia group, lethal 10- min ischemia group and ischemic preconditioning group. Neuronal death in the CA1 region was observed by hematoxylineosin staining, and number of live neurons was assessed by cell counting under a light microscope. Immunochemistry and laser scanning confocal microscopy were used to observe the distribution of chaperone hsp70 in the CA1 neurons. Differential centrifuge was used to isolate cytosol, nucleus and protein aggregates fractions. Western blot was used to analyze the quantitative alterations of protein aggregates and inducible chaperone hsp70 in cellular fractions and in protein aggregates under different ischemic conditions. Results Histological examination showed that ischemic preconditioning significantly reduced delayed neuronal death in the hippocampus CA1 region （P 〈 0.01 vs 10-min ischemia group）. Sublethal ischemic preconditioning induced chaperone hsp70 expression in the CA1 neurons after 24 h reperfusion following 10-min ischemia. Induced-hsp70 combined with the abnormal proteins produced during the secondary lethal 10-min ischemia and inhibited the formation of cytotoxic protein aggregates（P〈0.01 vs 10-min ischemia group）.Conelusion Ischemic preconditioning induced chaperone hsp70 expression and inhibited protein aggregates formation in the CA1 neurons when suffered secondary lethal ischemia, which may protect neurons from death.
文摘In order to solve the problem that the current matchmaking methods for semantic web service mainly focus on the matchmaking of IO （inputs, outputs） descriptions which may result in one-sidedness, a description-logic-based IOPE （inputs, outputs, preconditions, effects） description and matchmaking method is proposed for semantic web service. The description logic concept is used to annotate service IO and the description logic assertion is employed to describe service PE（preconditions, effects）. TBox subsumption checking is used to measure the subsumption relationship between IO descriptions of service request and advertising; ABox consistency checking is used for checking the logical implication between PE descriptions of service request and advertising. Based upon the logical implication, four kinds of PE matching degrees are proposed to measure and compare the pros and cons of the results of matchmaking. They are the exact, perfect, side-effect and common match. Experiments show that the method has a higher precision rate under the same recall rate compared with the existing method.
基金supported by theScience Foundation of Shihezi University,Xinjiang Province,China(No.RCZX200688)
文摘Objective Sevoflurane preconditioning has been demonstrated to reduce cerebral ischemia–reperfusion（IR） injury,but the underlying mechanisms have not been fully elucidated.Besides,different protocols would usually lead to different results.The objective of this study was to determine whether dual exposure to sevoflurane improves the effect of anesthetic preconditioning against oxygen and glucose deprivation（OGD）injury in vitro.Methods Rat hippocampal slices under normoxic conditions（95%O2/5%CO2）were pre-exposed to sevoflurane 1,2 and 3 minimum alveolar concentration （MAC）for 30 min,once or twice,with 15-min washout after each exposure.The slices were then subjected to 13-min OGD treatment（95%N2/5%CO2,glucose-free）,followed by 30-min reoxygenation.The population spikes（PSs）were recorded in the CA1 region of rat hippocampus.The percentage of PS amplitude at the end of 30-min reoxygenation to that before OGD treatment was calculated,since it could indicate the recovery degree of neuronal function.In addition,to assess the role of mitogen-activated protein kinases（MAPKs）in preconditioning,U0126,an inhibitor of extracellular signal–regulated protein kinase（MEK-ERK1/2,ERK1/2 MAPK）,and SB203580,an inhibitor of p38 MAPK,were separately added 10 min before sevoflurane exposure.Results Preconditioning once with sevoflurane 1,2,and 3 MAC increased the percentage of PS amplitude at the end of 30-min reoxygenation to that before OGD treatment,from（15.13±3.79）%（control）to（31.88±5.36）%, （44.00±5.01）%,and（49.50±6.25）%,respectively,and twice preconditioning with sevoflurane 1,2,and 3 MAC increased the percentage to（38.53±4.36）%,（50.74±7.05）%and（55.86±6.23）%,respectively.The effect of duplicate preconditioning with sevoflurane 3 MAC was blocked by U0126[（16.23±4.62）%].Conclusion Sevoflurane preconditioning can induce neuroprotection against OGD injury in vitro,and preconditioning twice enhances this effect.Besides,the activation of extracellular signal–regulated protein kinase（MEK-ERK1/2,ERK1/2 MAPK）may be involved in this process.
文摘Objective To investigate whether desferoxamine （DFO） preconditioning can induce tolerance against cerebral ischemia and its effect on the expression of hypoxia inducible factor 1 α （HIF- 1α） and erythropoietin （EPO） in vivo and in vitro. Methods Rat model of cerebral ischemia was established by middle cerebral artery occlusion with or without DFO administration. Infarct size was examined by TTC staining, and the neurological severity score was evaluated according to published method. Cortical neurons were cultured under ischemia stress which was mimicked by oxygen-glucose deprivation （OGD）, and the neuron damage was assessed by MTT assay. Immunofluorescent staining was employed to detect the expressions of HIF-1 and EPO. Results The protective effect induced by DFO （decreasing the infarction volume and ameliorating the neurological function） appeared at 2 d after administration ofDFO （post-DFO）, lasted until 7 d and disappeared at 14 d （P 〈 0.05）; the most effective action was observed at 3 d post-DFO. DFO induced tolerance of cultured neurons against OGD： neuronal viability was increased 23%, 34%, 40%, 48% and 56% at 8 h, 12 h, 24 h, 36 h, and 48 h, respectively, post-DFO （P 〈 0.05）. Immunofluorescent staining found that HIF-1 α and EPO were upregulated in the neurons of rat brain at 3 d and 7 d post-DFO; increase of HIF-1 α and EPO appeared in cultured cortex neurons at 36 h and 48 h post-DFO. Conclusion DFO induced tolerance against focal cerebral ischemia in rats, and exerted protective effect on OGD cultured cortical neurons. DFO significant induced the expression of HIF- 1 α and EPO both in vivo and in vitro. DFO preconditioning can protect against cerebral ischemia, which may be associated with the synthesis of HIF- 1 α and EPO.
文摘The preconditioning method is used to solve the low Mach number flow. The space discritisation scheme is the Roe scheme and the DES turbulence model is used. Then, the low Mach number turbulence flow around the NACA0012 airfoil is used to verify the efficiency of the proposed method. Two cases of the low Mach number flows around the multi-element airfoil and the circular cylinder are also used to test the proposed method. Numerical results show that the methods combined the preconditioning method and compressible Navier-Stokes equations are efficient to solve low Mach number flows.
基金the National Natural Science Foundation of China (No. 30570627)
文摘Objective To investigate the protective effects of hydrogen peroxide preconditioning （HPP） on the pheochromocytoma （PC12） cells treated with 1-methyl-4-phenylpyridinium （MPP^＋） and to explore the potential mechanisms. Methods The viability and apoptosis of PC 12 cells were determinded by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay and 4′,6′-diamidino-2-phenylindole （DAPI） staining, respectively. The expressions of 14-3-3 protein and phospholylated p38 mitogen-activated protein kinase （MAPK） were determined by Western blot. Enzyme-linked immunosorbent assay （ELISA） was used to measure the activity of extracellular signal-regulated protein kinase 1/2 （ERK1/2）. Results The cell viability decreased and the number of apoptotic cells increased dramatically in MPP^＋ group compared with that in Control group. HPP induced a significant increase in cell viability and a marked decrease in population of apoptotic cells of the MPP^＋- treated PC 12 cells, accompanied with up-regulation of 14-3-3 protein and increase of ERK 1/2 and p38 MAPK activities. The 14-3-3 protein expression was positively correlated with the phosphorylation of ERK1/2. Furthermore, inhibition of the ERK1/2 with PD98059 abolished the 14-3-3 protein up-regulation in PC 12 cells induced by HPP. Conclusion HPP protects PC 12 cells against MPP＋ toxicity by up-regulating 14-3-3 protein expression through the ERK1/2 and p38 MAPK signaling pathways.
基金the Foundation of Beijing Municipal Commission of Education,China (No.200410025011)
文摘Objective To identify the protective effect of lipopolysaccharide （LPS） preconditioning against LPS-induced inflammatory damage in dopaminergic neurons of midbrain slice culture and the possible mechanisms. Methods After cultured in vitro for 14 d, the rat organotypic midbrain slices were pretreated with different concentrations （0, 1, 3, 6 or 10 ng/mL） of LPS for 24 h followed by treatment with 100 ng/mL LPS for 72 h. The whole slice viability was detelmined by measurement of the activity of lactic acid dehydrogenase （LDH）. Tyrosine hydroxylase-immunoreactive （TH-IR） neurons and CD 1 1 b/c equivalent-immunoreactive （OX-42-IR） microglia in the slices were observed by immunohistochemical method, and tumor necrosis factor-α （TNF-α levels in the culture media were detected by enzymelinked immunosorbent assays （ELISA）. Results In the slices treated with 100 ng/mL LPS for 72 h, the number of TH-IR neurons reduced from 191± 12 in the control slices to 46±4, and the LDH activity elevated obviously （P 〈 0.01）, along with remarkably increased number of OX-42-IR cells and production of TNF-α （P 〈 0.01）. Preconditioning with 3 or 6 ng/mL LPS attenuated neuron loss （the number of TH-IR neurons increased to 126± 12 and 180± 13, respectively） and markedly reduced LDH levels （P 〈 0.05）, accompanied by significant decreases of OX-42-IR microglia activation and TNF-α production （P 〈 0.05）. Conclusion Low-dose LPS preconditioning could protect dopaminergic neurons against inflammatory damage in rat midbrain slice culture, and inhibition of microglial activation and reduction of the proinflammatory factor TNF-α production may contribute to this protective effect. Further understanding the underlying mechanism of LPS preconditioning may open a new window for treatment of Parkinson＇s disease.
文摘A new favorable iterative algorithm named as PBiCGSTAB （preconditioned bi-conjugate gradient stabilized） algorithm is presented for solving large sparse complex systems. Based on the orthogonal list, the special technique of only storing non-zero elements is carried out. The incomplete LU factorization without fill-ins is adopted to reduce the condition number of the coefficient matrix. The BiCGSTAB algorithm is extended from the real system to the complex system and it is used to solve the preconditioned complex linear equations. The locked-rotor state of a single-sided linear induction machine is simulated by the software programmed with the finite element method and the PBiCGSTAB algorithm. Then the results are compared with those from the commercial software ANSYS, showing the validation of the proposed software. The iterative steps required for the proposed algorithm are reduced to about one-third, when compared to the BiCG method, therefore the algorithm is fast.
基金the Science and Technology Bureau of South District of Qingdao, No. 2008041
文摘The present study established a model of brain ischemia in aged rats using four-vessel occlusion.We observed hippocampal CA1 neuronal apoptosis and apoptosis-mediated protease caspase-3 expression following preconditioning of electroacupuncture at Baihui（GV 20）.Our results showed that the number of hippocampal CA1 normal neurons was decreased,and degenerated neurons were increased 12 hours to 3 days following cerebral ischemia/reperfusion.The number of hippocampal CA1 apoptotic neurons and caspase-3-positive neurons in rats with cerebral ischemia/reperfusion injury was significantly decreased following acupuncture preconditioning.Acupuncture preconditioning protects aged rats against ischemia/reperfusion injury by regulating caspase-3 protein expression.
