Stroke can be categorized as ischemic and hemorrhagic on the basis of its origin.The pathophysiology following a stroke is complex,and is characterized by ongoing inflammation,neuronal injury,and the accumulation of r...Stroke can be categorized as ischemic and hemorrhagic on the basis of its origin.The pathophysiology following a stroke is complex,and is characterized by ongoing inflammation,neuronal injury,and the accumulation of reactive oxygen species in the brain,all of which reflect a dynamic process of change.This complexity hinders achievement of significant therapeutic outcomes with standard stroke treatment procedures,limiting post-stroke recovery.This review presents an innovative post-stroke therapeutic approach that utilizes nanomedicines to modify the cerebral microenvironment.It highlights the primary roles of chronic inflammation and nerve repair issues in causing prolonged impairment in stroke patients.Traditional therapies show limited effectiveness in achieving neuroprotection,immunoregulation,and neural regeneration during the subacute and chronic phases of stroke.Therefore,effective stroke management requires the use of specific therapeutic strategies tailored to the pathological characteristics of each phase.Various types of nanomedicines possess distinct physicochemical properties and can be selected on the basis of the specific therapeutic needs.Surface-modification technologies have significantly enhanced the ability of nanomedicines to penetrate the blood-brain barrier and improve their targeting capabilities in drug administration.However,the stability,biocompatibility,and long-term safety of nanomedicines require further optimization for clinical application.Nanomedicines represent a novel approach to stroke treatment through targeted delivery and multifaceted regulatory mechanisms.These medicines provide distinct advantages,particularly in addressing chronic inflammation and promoting nerve regeneration.As a result,nanomedicines are expected to significantly improve rehabilitation outcomes and quality of life for stroke patients in the future,emerging as a crucial modality for stroke treatment.展开更多
Traditional nerve repair methods,such as autologous nerve grafting and allogeneic nerve grafting,face issues such as donor shortage,functional loss,and immune rejection.Decellularized extracellular matrix-based grafts...Traditional nerve repair methods,such as autologous nerve grafting and allogeneic nerve grafting,face issues such as donor shortage,functional loss,and immune rejection.Decellularized extracellular matrix-based grafts have emerged as highly promising alternatives,capable of uniquely recreating the natural neural mic roenvironment,promoting host cell remodeling,and ultimately enhancing functional neural regeneration.This review comprehensively analyzes the key mechanisms of peripheral nerve injury and regeneration,focusing on contemporary therapeutic strategies for key aspects such as axonal apoptosis inhibition,enhanced intrinsic regenerative capacity,construction of regenerative microenvironment,and prevention of target organ atrophy.Findings from this review has shown that decellularized extra cellular matrix grafts can promote the migration,prolife ration,and differentiation of nerve cells by providing physical suppo rt,chemical signals,and mechanical stability.Decellularized extracellular matrix grafts are mainly used as ne rve conduits,scaffolds,hydrogels,and3D printing inks.Decellularized extra cellular matrix grafts have demonstrated significant advantages in promoting nerve regeneration by regulating the prolife ration and differentiation of Schwann cells,improving the neural microenvironment,reducing inflammato ry responses,and promoting angiogenesis.Additionally,decellularized extracellular matrix grafts can se rve as drug carrie rs,enabling the controlled release of growth factors,which further enhances nerve regeneration.However,these grafts also have some limitations,including the presence of immunogenic residues,inadequate mechanical prope rties,inter-batch variability,and uncontrollable degradation rates.Future research should focus on optimizing the decellularization process,enhancing the mechanical prope rties of decellularized extracellular matrix grafts,reducing immunogenicity,improving biocompatibility and safety,and developing new composite mate rials.Furthermore,exploring their application potential in complex nerve injuries,such as diabetic neuropathy,is crucial to meet the needs of peripheral nerve regeneration and repair.展开更多
Cannabidiol(CBD),the second most significant phytocannabinoid in the plant Cannabis sativa,which lacks potential as a drug of abuse(Viudez-Martinez et al.,2019),has gained widespread attention due to its anti-inflamma...Cannabidiol(CBD),the second most significant phytocannabinoid in the plant Cannabis sativa,which lacks potential as a drug of abuse(Viudez-Martinez et al.,2019),has gained widespread attention due to its anti-inflammatory,antioxidant,and antidepressant properties(Garci a-Gutierrez et al.,2020).Additionally,CBD exhibits neuroprotective properties,preserving neuronal viability and function by preventing or limiting cellular damage.Our team has demonstrated that CBD produces rapid antidepressant-like effects in a murine model of chronic mild stress,restoring hippocampal expression of brain-derived neurotrophic factor(BDNF).展开更多
Regenerative catalytic oxidizers(RCO)are widely used to remove volatile organic compounds(VOCs)due to their energy-saving and stability.In this study,a multi-component catalytic reaction model was constructed to numer...Regenerative catalytic oxidizers(RCO)are widely used to remove volatile organic compounds(VOCs)due to their energy-saving and stability.In this study,a multi-component catalytic reaction model was constructed to numerically investigate the reaction process of hydrocarbon-containing VOCs in RCO using computational fluid dynamics(CFD)simulation.To obtain the conversion characteristics of multi-component hydrocarbons,the effects of intake load,equivalence ratio,and the composition of multi-component hydrocarbons on the flow,heat transfer,and conversion rate of the reactor were analyzed.A feasibility study plan targeting the hard-to-convert components was also proposed.The results indicated that as the load increases,the conversion rates of the various components decrease,while the reaction rates increase.Moreover,increasing the flow velocity intensifies turbulence and enhances the collision frequency between the gas and the wall surfaces.This,in turn,amplifies the resistance effect of the porous medium.As the equivalence ratio of VOCs to oxygen increases,the oxygen-deficient condition leads to a decrease in the molecular weight of the hydrocarbons involved in the reaction.The reaction temperature also shows a downward trend.A comparative analysis of the catalytic combustion characteristics of multi-component VOCs and single-component gases reveals that adding ethane and propane can facilitate methane oxidation.展开更多
The osteochondral(OC)interface exhibits a mineral gradient,varying in thickness by several hundred micrometers across different species.Disruptions in this interface damage OC tissues,leading to osteoarthritis.The nat...The osteochondral(OC)interface exhibits a mineral gradient,varying in thickness by several hundred micrometers across different species.Disruptions in this interface damage OC tissues,leading to osteoarthritis.The natural architecture and composition of native OC interfaces can be replicated using biomaterial scaffolds via regenerative engineering approaches.A novel one-step bioextrusion process was employed to fabricate a unitary synthetic graft(USG),which mimics the native OC interface’s mineral concentration gradient.This novel USG is composed of an agarose-based cartilage layer and a bone layer,consisting of agarose enriched with 20%(200 g/L)hydroxyapatite.The USG features a gradient interface with mineral concentrations transitioning from 0%to 20%(mass fraction),mimicking the transition between the cartilage and bone.Thermogravimetric analysis revealed that the gradient transition lengths of the graft and native OC tissue harvested from bovine knees were similar((647±21)vs.(633±124)μm).The linear viscoelastic properties of the grafts,which were evaluated using strain sweep and frequency sweep tests with oscillatory shear,indicated a dominant storage modulus over loss modulus similar to that of native OC tissues.The compressive and stress relaxation behaviors of the USGs demonstrated that the graft maintained structural integrity under mechanical stress.Viability assays performed after bioextrusion showed that chondrocytes and human fetal osteoblast cells successfully integrated and survived within their designated regions of the graft.The novel USGs exhibit properties similar to native OC tissue and are promising candidates for regenerating OC defects and restoring knee joint functionality.展开更多
A recently published prospective study marks a breakthrough for congenital olfactory disorders in children.The study provides the first long-term,three-year follow-up data,robustly demonstrating the durable efficacy a...A recently published prospective study marks a breakthrough for congenital olfactory disorders in children.The study provides the first long-term,three-year follow-up data,robustly demonstrating the durable efficacy and safety of autologous nasal epithelial stem cell transplantation.This work reveals immense therapeutic potential for a condition traditionally considered untreatable.However,this milestone achievement also presents new challenges.To translate this pioneering therapy from a single-center success to a global standard,multicenter,controlled clinical trials must be initiated immediately.Only through rigorous validation can we ensure its widespread adoption and ultimately bring hope to millions of children worldwide.展开更多
Traumatic spinal cord injury(SCI)is a devastating central nervous system(CNS)disorder characterized by significant neurological dysfunction and sensory loss,and effective therapies that prevent neuronal loss and funct...Traumatic spinal cord injury(SCI)is a devastating central nervous system(CNS)disorder characterized by significant neurological dysfunction and sensory loss,and effective therapies that prevent neuronal loss and functional recovery remain elusive.After SCI,lesions are surrounded by neuroprotective borders formed by newly proliferated reactive astrocytes.Astrocyte proliferation and activation mediate the formation and function of the glial scar and influence the balance between protection and inflammation.展开更多
In recent years,the progression of stem cell therapies has shown great promise in advancing the nascent field of regenerative medicine.Considering the non-regenerative nature of the mature central nervous system,the c...In recent years,the progression of stem cell therapies has shown great promise in advancing the nascent field of regenerative medicine.Considering the non-regenerative nature of the mature central nervous system,the concept that“blank”cells could be reprogrammed and functionally integrated into host neural networks remained intriguing.Previous work has also demonstrated the ability of such cells to stimulate intrinsic growth programs in post-mitotic cells,such as neurons.While embryonic stem cells demonstrated great potential in treating central nervous system pathologies,ethical and technical concerns remained.These barriers,along with the clear necessity for this type of treatment,ultimately prompted the advent of induced pluripotent stem cells.The advantage of pluripotent cells in central nervous system regeneration is multifaceted,permitting differentiation into neural stem cells,neural progenitor cells,glia,and various neuronal subpopulations.The precise spatiotemporal application of extrinsic growth factors in vitro,in addition to microenvironmental signaling in vivo,influences the efficiency of this directed differentiation.While the pluri-or multipotency of these cells is appealing,it also poses the risk of unregulated differentiation and teratoma formation.Cells of the neuroectodermal lineage,such as neuronal subpopulations and glia,have been explored with varying degrees of success.Although the risk of cancer or teratoma formation is greatly reduced,each subpopulation varies in effectiveness and is influenced by a myriad of factors,such as the timing of the transplant,pathology type,and the ratio of accompanying progenitor cells.Furthermore,successful transplantation requires innovative approaches to develop delivery vectors that can mitigate cell death and support integration.Lastly,host immune responses to allogeneic grafts must be thoroughly characterized and further developed to reduce the need for immunosuppression.Translation to a clinical setting will involve careful consideration when assessing both physiologic and functional outcomes.This review will highlight both successes and challenges faced when using human induced pluripotent stem cell-derived cell transplantation therapies to promote endogenous regeneration.展开更多
BACKGROUND Incisional hernias are a common complication of previous surgeries and remain a persistent issue in clinical practice,posing a significant burden on healthcare systems despite advances in education and tech...BACKGROUND Incisional hernias are a common complication of previous surgeries and remain a persistent issue in clinical practice,posing a significant burden on healthcare systems despite advances in education and technology.Surgical techniques,primarily involving the use of mesh to cover the abdominal wall gap,are widely used as a standard intervention strategy.AIM To examine the regeneration of the aponeurosis defect in the anterior abdominal wall in rats using regenerative mimetic factors of the extracellular matrix[ReGeneraTing Agent(RGTA)],adipose tissue micrografts(ATM),and platelet rich plasma(PRP)as regenerative agents.METHODS Regenerative agents such as RGTA,ATM,and PRP are gaining popularity.ATM involves autologous adipose tissue cells with mesenchymal stem cell markers and a high percentage of stromal vascular fraction cells.RGTAs are heparan sulfate(HS)mimetics that replace degraded HSs in damaged tissue,enhancing the quality and speed of repair.PRP is a concentrated plasma preparation containing seven fundamental proteins responsible for tissue production.An acellular dermal matrix is a biological implant free of cellular or antigenic components,making it an excellent material for reconstructive surgery.Polyglactin is a synthetic,absorbable mesh that loses 50%of its strength after fourteen days,providing initial support for new tissue regeneration before being completely absorbed.RESULTS Rats will undergo a laparotomy with a precise 2 cm by 2 cm excision of the anterior abdominal wall fascia below the umbilicus.They will be divided into sixteen groups,each receiving different combinations of regenerative factor injections into the denervated area in both non-contaminated and contaminated environments.A collagenelastin matrix will be used to join the aponeurosis edges,with an absorbable polyglactin mesh anchored over it.Samples will be taken for macroscopic,histological,and immunohistochemical evaluation of tissue regeneration.CONCLUSION Our study aims to demonstrate how these factors promote cell proliferation and healing of the denervated anterior abdominal wall,potentially reducing the frequency and complications of incisional hernias.This approach could offer a more economical and efficient treatment option compared to current costly methods.展开更多
Periodontal bone defects,primarily caused by periodontitis,are highly prevalent in clinical settings and manifest as bone fenestration,dehiscence,or attachment loss,presenting a significant challenge to oral health.In...Periodontal bone defects,primarily caused by periodontitis,are highly prevalent in clinical settings and manifest as bone fenestration,dehiscence,or attachment loss,presenting a significant challenge to oral health.In regenerative medicine,harnessing developmental principles for tissue repair offers promising therapeutic potential.Of particular interest is the condensation of progenitor cells,an essential event in organogenesis that has inspired clinically effective cell aggregation approaches in dental regeneration.However,the precise cellular coordination mechanisms during condensation and regeneration remain elusive.Here,taking the tooth as a model organ,we employed single-cell RNA sequencing to dissect the cellular composition and heterogeneity of human dental follicle and dental papilla,revealing a distinct Platelet-derived growth factor receptor alpha(PDGFRA)mesenchymal stem/stromal cell(MSC)population with remarkable odontogenic potential.Interestingly,a reciprocal paracrine interaction between PDGFRA^(+)dental follicle stem cells(DFSCs)and CD31^(+)Endomucin^(+)endothelial cells(ECs)was mediated by Vascular endothelial growth factor A(VEGFA)and Platelet-derived growth factor subunit BB(PDGFBB).This crosstalk not only maintains the functionality of PDGFRA^(+)DFSCs but also drives specialized angiogenesis.In vivo periodontal bone regeneration experiments further reveal that communication between PDGFRA+DFSC aggregates and recipient ECs is essential for effective angiogenic-osteogenic coupling and rapid tissue repair.Collectively,our results unravel the importance of MSC-EC crosstalk mediated by the VEGFA and PDGFBB-PDGFRA reciprocal signaling in orchestrating angiogenesis and osteogenesis.These findings not only establish a framework for deciphering and promoting periodontal bone regeneration in potential clinical applications but also offer insights for future therapeutic strategies in dental or broader regenerative medicine.展开更多
BACKGROUND Bone regeneration is a central focus of regenerative medicine,with applications in orthopedics and dentistry,particularly for treating bone defects caused by trauma,infection,or congenital anomalies.Synthet...BACKGROUND Bone regeneration is a central focus of regenerative medicine,with applications in orthopedics and dentistry,particularly for treating bone defects caused by trauma,infection,or congenital anomalies.Synthetic biomaterials,often combined with fibrin derivatives,offer promising solutions for bone healing and restoration.AIM To Explore the increasingly important role of the association of synthetic biomaterials with fibrin in bone regeneration.METHODS Search terms included:“synthetic biomaterials AND fibrin sealant”,“hydroxyapatite AND fibrin sealant”,“tricalcium phosphate AND fibrin sealant”,and“synthetic biomaterials AND platelet-rich fibrin(PRF)”,resulting in 67 articles.After rigorous screening,21 articles met the inclusion criteria.RESULTS The reviewed studies assessed biomaterials like hydroxyapatite(HA),β-tricalcium phosphate(β-TCP),and fibrin-based products.Key findings highlighted the enhanced osteoconductivity and biocompatibility of HA andβ-TCP,especially when combined with fibrin sealants.These composites show significant potential for improving cellular adhesion,promoting osteogenic differentiation,and accelerating bone regeneration.The antimicrobial properties and structural support for cell growth of certain biomaterials indicate a promising potential for clinical applic-ations.CONCLUSION This systematic review emphasizes the growing role of fibrin-based biomaterials in bone regeneration and urges continued research to improve their clinical use for complex bone defects.展开更多
Bone defects caused by trauma,infection,or congenital anomalies remain a significant challenge in orthopedic and dental practice,necessitating innovative strategies to enhance healing and functional restoration.This s...Bone defects caused by trauma,infection,or congenital anomalies remain a significant challenge in orthopedic and dental practice,necessitating innovative strategies to enhance healing and functional restoration.This systematic review by Pagani et al synthesizes evidence on the synergistic role of synthetic biomaterials,such as hydroxyapatite(HA)andβ-tricalcium phosphate(β-TCP),combined with fibrin derivatives in bone regeneration.Analyzing 21 studies,the authors demonstrate that HA andβ-TCP composites exhibit superior osteoconductivity and biocompatibility when integrated with fibrin sealants or plateletrich fibrin,promoting cellular adhesion,osteogenic differentiation,and accelerated healing.While these studies underscore the potential of these biomaterialfibrin hybrids,limitations such as variability in fibrin preparation,lack of longterm data,and insufficient standardization hinder clinical translation.This editorial contextualizes these findings within the evolving landscape of regenerative medicine,emphasizing the need for optimized formulations,interdisciplinary collaboration,and robust clinical trials to bridge laboratory innovation to bedside application.展开更多
BACKGROUND Exosome-based therapies represent a promising approach for hair regeneration.Unlike conventional treatments such as minoxidil and finasteride,exosomes deliver bioactive cargo that can stimulate dermal papil...BACKGROUND Exosome-based therapies represent a promising approach for hair regeneration.Unlike conventional treatments such as minoxidil and finasteride,exosomes deliver bioactive cargo that can stimulate dermal papilla cells,enhance angiogenesis,and modulate inflammatory pathways.However,variability in exosome sources,isolation techniques,and dosing protocols limits their clinical translation.AIM To synthesize findings from in vitro,preclinical and clinical studies,and to evaluate the efficacy,mechanisms,and challenges associated with exosome-based hair restoration therapies.METHODS A literature search was conducted using multiple databases(PubMed/Medline,Embase,Scopus,and Web of Science)employing terms for exosomes and hair regeneration for articles published in English to February 2025,following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.RESULTS A total of 27 studies(three in vitro,three pre-clinical,18 with both in vitro and preclinical component and three clinical)met the pre-defined search and inclusion criteria and were included in this review.CONCLUSION Exosome-based therapies hold immense promise for hair regeneration by leveraging their ability to modulate key signaling pathways and enhance hair follicle regeneration.While in vitro and preclinical studies demonstrate consistent efficacy across diverse exosome sources,methodological heterogeneity and a limited number of clinical studies warrant further clinical research to realize their full clinical potential for hair regeneration.展开更多
Bone marrow cells for the treatment of ischemic brain injury may depend on the secretion of a large number of neurotrophic factors. Bone marrow regenerative cells are capable of increasing the secretion of neurotrophi...Bone marrow cells for the treatment of ischemic brain injury may depend on the secretion of a large number of neurotrophic factors. Bone marrow regenerative cells are capable of increasing the secretion of neurotrophic factors. In this study, after tail vein injection of 5-fluorouracil for 7 days, bone marrow cells and bone marrow regenerative cells were isolated from the tibias and femurs of rats, and then administered intravenously via the tail vein after focal cerebral ischemia. Immunohistological staining and reverse transcription-PCR detection showed that transplanted bone marrow cells and bone marrow regenerative cells could migrate and survive in the ischemic regions, such as the cortical and striatal infarction zone. These cells promote vascular endothelial cell growth factor mRNA expression in the ischemic marginal zone surrounding the ischemic penumbra of the cortical and striatal infarction zone, and have great advantages in promoting the recovery of neurological function, reducing infarct size and promoting angiogenesis. Bone marrow regenerative cells exhibited stronger neuroprotective effects than bone marrow cells. Our experimental findings indicate that bone marrow regenerative cells are preferable over bone marrow cells for cell therapy for neural regeneration after cerebral ischemia. Their neuroprotective effect is largely due to their ability to induce the secretion of factors that promote vascular regeneration, such as vascular endothelial growth factor.展开更多
As surgical procedures transition from conventional resection to advanced tissue-regeneration technologies,human disease therapy has witnessed a great leap forward.In particular,three-dimensional(3D)bioprinting stands...As surgical procedures transition from conventional resection to advanced tissue-regeneration technologies,human disease therapy has witnessed a great leap forward.In particular,three-dimensional(3D)bioprinting stands as a landmark in this setting,by promising the precise integration of biomaterials,cells,and bioactive molecules,thus opening up a novel avenue for tissue/organ regeneration.Curated by the editorial board of Bio-Design and Manufacturing,this review brings together a cohort of leading young scientists in China to dissect the core functionalities and evolutionary trajectory of 3D bioprinting,by elucidating the intricate challenges encountered in the manufacturing of transplantable organs.We further delve into the translational pathway from scientific research to clinical application,emphasizing the imperativeness of establishing a regulatory framework and rigorously enforcing quality-control measures.Finally,this review outlines the strategic landscape and innovative achievements of China in this field and provides a comprehensive roadmap for researchers worldwide to propel this field collectively to even greater heights.展开更多
The regenerative braking energy utilization system(RBEUS)stands as a promising technique for improving the efficiency and power quality of electrified railways.Beyond the vital aspects of energy management and control...The regenerative braking energy utilization system(RBEUS)stands as a promising technique for improving the efficiency and power quality of electrified railways.Beyond the vital aspects of energy management and control strategies,ensuring fault protection is paramount for the secure and steady operation of the traction power supply system(TPSS)integrated with RBEUS.This paper introduces an innovative protection scheme tailored to diverse RBEUS application scenarios.Firstly,fault categories are streamlined into three levels:system,equipment,and warning.Subsequently,a novel multi-port active power differential protection method,aligned with RBEUS operational principles,is crafted to serve as a comprehensive and sensitive main protection.Building upon this foundation,a hierarchical protection structure for RBEUS is established,addressing the intricacies and variations in fault types while boosting anti-disturbance capabilities under faulty conditions.Embracing the principle of railway-oriented safety,a collaborative RBEUS-TPSS protection scheme is put forth.Finally,through simulated scenarios encompassing various fault conditions,the proposed scheme’s feasibility and effectiveness are convincingly validated.展开更多
Due to the complex high-temperature characteristics of hydrocarbon fuel,the research on the long-term working process of parallel channel structure under variable working conditions,especially under high heat-mass rat...Due to the complex high-temperature characteristics of hydrocarbon fuel,the research on the long-term working process of parallel channel structure under variable working conditions,especially under high heat-mass ratio,has not been systematically carried out.In this paper,the heat transfer and flow characteristics of related high temperature fuels are studied by using typical engine parallel channel structure.Through numeri⁃cal simulation and systematic experimental verification,the flow and heat transfer characteristics of parallel chan⁃nels under typical working conditions are obtained,and the effectiveness of high-precision calculation method is preliminarily established.It is known that the stable time required for hot start of regenerative cooling engine is about 50 s,and the flow resistance of parallel channel structure first increases and then decreases with the in⁃crease of equivalence ratio(The following equivalence ratio is expressed byΦ),and there is a flow resistance peak in the range ofΦ=0.5~0.8.This is mainly caused by the coupling effect of high temperature physical proper⁃ties,flow rate and pressure of fuel in parallel channels.At the same time,the cooling and heat transfer character⁃istics of parallel channels under some conditions of high heat-mass ratio are obtained,and the main factors affect⁃ing the heat transfer of parallel channels such as improving surface roughness and strengthening heat transfer are mastered.In the experiment,whenΦis less than 0.9,the phenomenon of local heat transfer enhancement and deterioration can be obviously observed,and the temperature rise of local structures exceeds 200℃,which is the risk of structural damage.Therefore,the reliability of long-term parallel channel structure under the condition of high heat-mass ratio should be fully considered in structural design.展开更多
A unitized regenerative fuel cell(URFC)is a device that may function reversibly as either a fuel cell(FC)or water elec-trolysis(WE).An important component of this device is the Membrane electrode assembly(MEA).Therefo...A unitized regenerative fuel cell(URFC)is a device that may function reversibly as either a fuel cell(FC)or water elec-trolysis(WE).An important component of this device is the Membrane electrode assembly(MEA).Therefore,this study aimed to compare the performance outcomes of MEA using electrodes with single and three catalyst layers.This study measured Electrochemical Surface Area(ECSA),Electrochemical Impedance Spectroscopy(EIS),X-ray Diffraction analysis(XRD),and X-ray Fluorescence(XRF).Furthermore,the round-trip efficiency(RTE)of the MEA,as w ell as the performance in FC and WE mode,was measured.In comparison,The ECSA values of Pt-Ru/C and Pt/C with three catalyst layers were higher than the single catalyst layer.This result was supported by electrode characterization data for XRD and XRF.The respective electrical conductivity values of Pt-Ru/C and Pt/C with three catalyst layers are also higher than the single cata-lyst layer,and the performance of URFC using MEA with three catalyst layers has the highest value of RTE among the MEA performances of URFC,which is 100%at a current density of 4 mA·cm-2.展开更多
Conjunctival goblet cells are of great significance to the ocular surface.By secreting mucins-particularly MUC5AC-they play a pivotal role in stabilizing the tear film,safeguarding the cornea from environmental insult...Conjunctival goblet cells are of great significance to the ocular surface.By secreting mucins-particularly MUC5AC-they play a pivotal role in stabilizing the tear film,safeguarding the cornea from environmental insults,and preserving overall ocular homeostasis.Over the past decade,remarkable progress has been made in understanding the distinctive biological characteristics and regenerative potential of these specialized cells,opening novel avenues for treating various ocular surface disorders,ranging from dry eye syndrome and allergic conjunctivitis to more severe conditions such as Stevens-Johnson syndrome.This review comprehensively examines the morphology,function,and regulation of conjunctival goblet cells.Advanced imaging modalities,such as transmission electron microscopy,have provided in-depth insights into their ultrastructure.Densely packed mucin granules and a specialized secretory apparatus have been uncovered,highlighting the cells’proficiency in producing and releasing MUC5AC.These structural characterizations have significantly enhanced our understanding of how goblet cells contribute to maintaining a stable and protective mucosal barrier,which is crucial for ocular surface integrity.The review further delves into the intricate signaling networks governing the differentiation and regeneration of these cells.Key pathways,including Notch,Wnt/β-catenin,and TGF-β,have emerged as essential regulators of cell fate decisions,ensuring that goblet cells maintain their specialized functions.Critical transcription factors,such as Klf4,Klf5,and SPDEF,have been identified as indispensable for driving the differentiation process and sustaining the mature phenotype of goblet cells.Additionally,the modulatory effects of inflammatory mediators-such as IL-6,IL-13,and TNF-α-and growth factors,such as EGF and FGF,are explored.These molecular insights offer a robust framework for understanding the pathophysiological mechanisms underlying ocular surface diseases,wherein the dysregulation of these processes often results in diminished goblet cell numbers and impaired tear film stability.Innovative methodological approaches have provided a strong impetus to this field.The development of three-dimensional(3D)in vitro culture systems that replicate the native conjunctival microenvironment has enabled more physiologically relevant investigations of goblet cell biology.Moreover,the integration of stem cell technologies-including the use of induced pluripotent stem cells(iPSCs)and bone marrow-derived mesenchymal stem cells(BM-MSCs)-has made it possible to generate goblet cell-like epithelia,thereby presenting promising strategies for tissue engineering and regenerative therapies.The application of artificial intelligence in optimizing drug screening and biomaterial scaffold design represents an exciting frontier that may accelerate the translation of these findings into effective clinical interventions.In conclusion,this review underscores the central role of conjunctival goblet cells in preserving ocular surface health and illuminates the transformative potential of emerging regenerative approaches.Continued research focused on deciphering the intricate molecular mechanisms governing goblet cell function and regeneration is essential for developing innovative,targeted therapies that can significantly improve the management of ocular surface diseases and enhance patient quality of life.展开更多
In liquid rocket engines,regenerative cooling technology is essential for preserving structural integrity under extreme thermal loads.However,non-uniform coolant flow distribution within the cooling channels often lea...In liquid rocket engines,regenerative cooling technology is essential for preserving structural integrity under extreme thermal loads.However,non-uniform coolant flow distribution within the cooling channels often leads to localized overheating,posing serious risks to engine reliability and operational lifespan.This study employs a three-dimensional fluid–thermal coupled numerical model to systematically investigate the influence of geometric parameters-specifically the number of inlets,the number of channels,and inlet manifold configurations-on flow uniformity and thermal distribution in non-pyrolysis zones.Key findings reveal that increasing the number of inlets from one to three significantly enhances flow uniformity,reducing mass flow rate deviation from 1.2%to below 0.3%.However,further increasing the inlets to five yields only marginal improvements indicating diminishing(<0.1%),returns beyond three inlets.Additionally,temperature non-uniformity at the combustion chamber throat decreases by 37%-from 3050 K with 18 channels to 1915 K with 30 channels-highlighting the critical role of channel density in effective thermal regulation.Notably,while higher channel counts improve cooling efficiency,they also result in increased pressure losses of approximately 18%–22%,emphasizing the need to balance thermal performance against hydraulic resistance.An optimal configuration comprising 24 channels and three inlets was identified,providing minimal temperature gradients while maintaining acceptable pressure losses.The inlet manifold structure also plays a pivotal role in determining flow distribution.Configuration 3(Config-3),which features an enlarged manifold and reduced inlet velocity,achieves a 40%reduction in velocity fluctuations compared to Configuration 1(Config-1).This improvement leads to a more uniform mass flow distribution,with a relative standard deviation(RSD)of less than 0.15%.Furthermore,this design effectively mitigates localized hot spots near the nozzle-where temperature gradients are most severe-achieving a reduction of approximately 1135 K.展开更多
基金supported by the National Natural Science Foundation of China,Nos.82272616(to ZL),82271325(to WS)the Natural Science Foundation of Beijing,No.7252076(to YR).
文摘Stroke can be categorized as ischemic and hemorrhagic on the basis of its origin.The pathophysiology following a stroke is complex,and is characterized by ongoing inflammation,neuronal injury,and the accumulation of reactive oxygen species in the brain,all of which reflect a dynamic process of change.This complexity hinders achievement of significant therapeutic outcomes with standard stroke treatment procedures,limiting post-stroke recovery.This review presents an innovative post-stroke therapeutic approach that utilizes nanomedicines to modify the cerebral microenvironment.It highlights the primary roles of chronic inflammation and nerve repair issues in causing prolonged impairment in stroke patients.Traditional therapies show limited effectiveness in achieving neuroprotection,immunoregulation,and neural regeneration during the subacute and chronic phases of stroke.Therefore,effective stroke management requires the use of specific therapeutic strategies tailored to the pathological characteristics of each phase.Various types of nanomedicines possess distinct physicochemical properties and can be selected on the basis of the specific therapeutic needs.Surface-modification technologies have significantly enhanced the ability of nanomedicines to penetrate the blood-brain barrier and improve their targeting capabilities in drug administration.However,the stability,biocompatibility,and long-term safety of nanomedicines require further optimization for clinical application.Nanomedicines represent a novel approach to stroke treatment through targeted delivery and multifaceted regulatory mechanisms.These medicines provide distinct advantages,particularly in addressing chronic inflammation and promoting nerve regeneration.As a result,nanomedicines are expected to significantly improve rehabilitation outcomes and quality of life for stroke patients in the future,emerging as a crucial modality for stroke treatment.
基金National Natural Science Foundation of China,No.32130060,No.81901256Jiangsu College Students Innovation and En trepreneurship Training Program,No.202310304120Y,No.202313993004Y2024 Medical Research Project by the Jiangsu Commission of Health,No.M2024009。
文摘Traditional nerve repair methods,such as autologous nerve grafting and allogeneic nerve grafting,face issues such as donor shortage,functional loss,and immune rejection.Decellularized extracellular matrix-based grafts have emerged as highly promising alternatives,capable of uniquely recreating the natural neural mic roenvironment,promoting host cell remodeling,and ultimately enhancing functional neural regeneration.This review comprehensively analyzes the key mechanisms of peripheral nerve injury and regeneration,focusing on contemporary therapeutic strategies for key aspects such as axonal apoptosis inhibition,enhanced intrinsic regenerative capacity,construction of regenerative microenvironment,and prevention of target organ atrophy.Findings from this review has shown that decellularized extra cellular matrix grafts can promote the migration,prolife ration,and differentiation of nerve cells by providing physical suppo rt,chemical signals,and mechanical stability.Decellularized extracellular matrix grafts are mainly used as ne rve conduits,scaffolds,hydrogels,and3D printing inks.Decellularized extra cellular matrix grafts have demonstrated significant advantages in promoting nerve regeneration by regulating the prolife ration and differentiation of Schwann cells,improving the neural microenvironment,reducing inflammato ry responses,and promoting angiogenesis.Additionally,decellularized extracellular matrix grafts can se rve as drug carrie rs,enabling the controlled release of growth factors,which further enhances nerve regeneration.However,these grafts also have some limitations,including the presence of immunogenic residues,inadequate mechanical prope rties,inter-batch variability,and uncontrollable degradation rates.Future research should focus on optimizing the decellularization process,enhancing the mechanical prope rties of decellularized extracellular matrix grafts,reducing immunogenicity,improving biocompatibility and safety,and developing new composite mate rials.Furthermore,exploring their application potential in complex nerve injuries,such as diabetic neuropathy,is crucial to meet the needs of peripheral nerve regeneration and repair.
基金supported by Instituto de Salud CarlosⅢ,Spanish Ministry of Science and Innovation,grant number PI18/00576 to MSGG and JMRRed de Investigación en Atención Primaria de Adicciones,Instituto de Salud CarlosⅢ,Spanish Ministry of Science and Innovation,grant number RD21/0009/0008 and RD24/0003/0002+1 种基金Instituto de Investigación Sanitaria y Biomédica de Alicante(ISABIAL)to JMThe Instituto de Neurociencias is a“Centre of Excellence Severo Ochoa”(CEX2021-001165-S).
文摘Cannabidiol(CBD),the second most significant phytocannabinoid in the plant Cannabis sativa,which lacks potential as a drug of abuse(Viudez-Martinez et al.,2019),has gained widespread attention due to its anti-inflammatory,antioxidant,and antidepressant properties(Garci a-Gutierrez et al.,2020).Additionally,CBD exhibits neuroprotective properties,preserving neuronal viability and function by preventing or limiting cellular damage.Our team has demonstrated that CBD produces rapid antidepressant-like effects in a murine model of chronic mild stress,restoring hippocampal expression of brain-derived neurotrophic factor(BDNF).
基金supported by National Key Research&Development Program of China(2022YFB4101500).
文摘Regenerative catalytic oxidizers(RCO)are widely used to remove volatile organic compounds(VOCs)due to their energy-saving and stability.In this study,a multi-component catalytic reaction model was constructed to numerically investigate the reaction process of hydrocarbon-containing VOCs in RCO using computational fluid dynamics(CFD)simulation.To obtain the conversion characteristics of multi-component hydrocarbons,the effects of intake load,equivalence ratio,and the composition of multi-component hydrocarbons on the flow,heat transfer,and conversion rate of the reactor were analyzed.A feasibility study plan targeting the hard-to-convert components was also proposed.The results indicated that as the load increases,the conversion rates of the various components decrease,while the reaction rates increase.Moreover,increasing the flow velocity intensifies turbulence and enhances the collision frequency between the gas and the wall surfaces.This,in turn,amplifies the resistance effect of the porous medium.As the equivalence ratio of VOCs to oxygen increases,the oxygen-deficient condition leads to a decrease in the molecular weight of the hydrocarbons involved in the reaction.The reaction temperature also shows a downward trend.A comparative analysis of the catalytic combustion characteristics of multi-component VOCs and single-component gases reveals that adding ethane and propane can facilitate methane oxidation.
基金supported by the School of Engineering and Digital Sciences of Nazarbayev University,Astana,Kazakhstan(to CE)。
文摘The osteochondral(OC)interface exhibits a mineral gradient,varying in thickness by several hundred micrometers across different species.Disruptions in this interface damage OC tissues,leading to osteoarthritis.The natural architecture and composition of native OC interfaces can be replicated using biomaterial scaffolds via regenerative engineering approaches.A novel one-step bioextrusion process was employed to fabricate a unitary synthetic graft(USG),which mimics the native OC interface’s mineral concentration gradient.This novel USG is composed of an agarose-based cartilage layer and a bone layer,consisting of agarose enriched with 20%(200 g/L)hydroxyapatite.The USG features a gradient interface with mineral concentrations transitioning from 0%to 20%(mass fraction),mimicking the transition between the cartilage and bone.Thermogravimetric analysis revealed that the gradient transition lengths of the graft and native OC tissue harvested from bovine knees were similar((647±21)vs.(633±124)μm).The linear viscoelastic properties of the grafts,which were evaluated using strain sweep and frequency sweep tests with oscillatory shear,indicated a dominant storage modulus over loss modulus similar to that of native OC tissues.The compressive and stress relaxation behaviors of the USGs demonstrated that the graft maintained structural integrity under mechanical stress.Viability assays performed after bioextrusion showed that chondrocytes and human fetal osteoblast cells successfully integrated and survived within their designated regions of the graft.The novel USGs exhibit properties similar to native OC tissue and are promising candidates for regenerating OC defects and restoring knee joint functionality.
文摘A recently published prospective study marks a breakthrough for congenital olfactory disorders in children.The study provides the first long-term,three-year follow-up data,robustly demonstrating the durable efficacy and safety of autologous nasal epithelial stem cell transplantation.This work reveals immense therapeutic potential for a condition traditionally considered untreatable.However,this milestone achievement also presents new challenges.To translate this pioneering therapy from a single-center success to a global standard,multicenter,controlled clinical trials must be initiated immediately.Only through rigorous validation can we ensure its widespread adoption and ultimately bring hope to millions of children worldwide.
基金supported by a Grant-in-Aid of AMED under Grant Numbers(JP22gm1510009)to RM.
文摘Traumatic spinal cord injury(SCI)is a devastating central nervous system(CNS)disorder characterized by significant neurological dysfunction and sensory loss,and effective therapies that prevent neuronal loss and functional recovery remain elusive.After SCI,lesions are surrounded by neuroprotective borders formed by newly proliferated reactive astrocytes.Astrocyte proliferation and activation mediate the formation and function of the glial scar and influence the balance between protection and inflammation.
基金supported by Ohio State Start Up FundNational Institutes of Health(NIH)+12 种基金Department of Defense(DoD)Wings for Life Spinal Cord Research Foundation,Wings for Life Spinal Cord Research Foundation(Austria)California Institute of Regenerative Medicine(CIRM)International Spinal Research Trust(United Kingdom)Stanford University Bio-X Program Interdisciplinary Initiatives Seed Grant IIP-7Dennis Chan FoundationKlein Family FundLucile Packard Foundation for Children's HealthStanford Institute for Neuro-Innovation and Translational Neurosciences(SINTN)Saunders Family Neuroscience FundJames Doty Neurosurgery FundHearst Neuroscience FundEileen Bond Research Fund(to GP)。
文摘In recent years,the progression of stem cell therapies has shown great promise in advancing the nascent field of regenerative medicine.Considering the non-regenerative nature of the mature central nervous system,the concept that“blank”cells could be reprogrammed and functionally integrated into host neural networks remained intriguing.Previous work has also demonstrated the ability of such cells to stimulate intrinsic growth programs in post-mitotic cells,such as neurons.While embryonic stem cells demonstrated great potential in treating central nervous system pathologies,ethical and technical concerns remained.These barriers,along with the clear necessity for this type of treatment,ultimately prompted the advent of induced pluripotent stem cells.The advantage of pluripotent cells in central nervous system regeneration is multifaceted,permitting differentiation into neural stem cells,neural progenitor cells,glia,and various neuronal subpopulations.The precise spatiotemporal application of extrinsic growth factors in vitro,in addition to microenvironmental signaling in vivo,influences the efficiency of this directed differentiation.While the pluri-or multipotency of these cells is appealing,it also poses the risk of unregulated differentiation and teratoma formation.Cells of the neuroectodermal lineage,such as neuronal subpopulations and glia,have been explored with varying degrees of success.Although the risk of cancer or teratoma formation is greatly reduced,each subpopulation varies in effectiveness and is influenced by a myriad of factors,such as the timing of the transplant,pathology type,and the ratio of accompanying progenitor cells.Furthermore,successful transplantation requires innovative approaches to develop delivery vectors that can mitigate cell death and support integration.Lastly,host immune responses to allogeneic grafts must be thoroughly characterized and further developed to reduce the need for immunosuppression.Translation to a clinical setting will involve careful consideration when assessing both physiologic and functional outcomes.This review will highlight both successes and challenges faced when using human induced pluripotent stem cell-derived cell transplantation therapies to promote endogenous regeneration.
文摘BACKGROUND Incisional hernias are a common complication of previous surgeries and remain a persistent issue in clinical practice,posing a significant burden on healthcare systems despite advances in education and technology.Surgical techniques,primarily involving the use of mesh to cover the abdominal wall gap,are widely used as a standard intervention strategy.AIM To examine the regeneration of the aponeurosis defect in the anterior abdominal wall in rats using regenerative mimetic factors of the extracellular matrix[ReGeneraTing Agent(RGTA)],adipose tissue micrografts(ATM),and platelet rich plasma(PRP)as regenerative agents.METHODS Regenerative agents such as RGTA,ATM,and PRP are gaining popularity.ATM involves autologous adipose tissue cells with mesenchymal stem cell markers and a high percentage of stromal vascular fraction cells.RGTAs are heparan sulfate(HS)mimetics that replace degraded HSs in damaged tissue,enhancing the quality and speed of repair.PRP is a concentrated plasma preparation containing seven fundamental proteins responsible for tissue production.An acellular dermal matrix is a biological implant free of cellular or antigenic components,making it an excellent material for reconstructive surgery.Polyglactin is a synthetic,absorbable mesh that loses 50%of its strength after fourteen days,providing initial support for new tissue regeneration before being completely absorbed.RESULTS Rats will undergo a laparotomy with a precise 2 cm by 2 cm excision of the anterior abdominal wall fascia below the umbilicus.They will be divided into sixteen groups,each receiving different combinations of regenerative factor injections into the denervated area in both non-contaminated and contaminated environments.A collagenelastin matrix will be used to join the aponeurosis edges,with an absorbable polyglactin mesh anchored over it.Samples will be taken for macroscopic,histological,and immunohistochemical evaluation of tissue regeneration.CONCLUSION Our study aims to demonstrate how these factors promote cell proliferation and healing of the denervated anterior abdominal wall,potentially reducing the frequency and complications of incisional hernias.This approach could offer a more economical and efficient treatment option compared to current costly methods.
基金supported by grants from the National Key Research and Development Program of China(2022YFA1104400)the National Natural Science Foundation of China(82170988,82371020,82301028,82401201,82471011)+5 种基金the Young Science and Technology Rising Star Project of Shaanxi Province(2024ZC-KJXX-122)the China Postdoctoral Science Foundation(BX20230485)the Project of State Key Laboratory of Oral&Maxillofacial Reconstruction and Regeneration(2024MS04)the Shaanxi Provincial Health Research and Innovation Platform Construction Plan(2024PT-04)the“Rapid Response”Research projects(2023KXKT017 and 2023KXKT090)the Intramural Research Program project founded by Fourth Military Medical University(2024QMJJ008).
文摘Periodontal bone defects,primarily caused by periodontitis,are highly prevalent in clinical settings and manifest as bone fenestration,dehiscence,or attachment loss,presenting a significant challenge to oral health.In regenerative medicine,harnessing developmental principles for tissue repair offers promising therapeutic potential.Of particular interest is the condensation of progenitor cells,an essential event in organogenesis that has inspired clinically effective cell aggregation approaches in dental regeneration.However,the precise cellular coordination mechanisms during condensation and regeneration remain elusive.Here,taking the tooth as a model organ,we employed single-cell RNA sequencing to dissect the cellular composition and heterogeneity of human dental follicle and dental papilla,revealing a distinct Platelet-derived growth factor receptor alpha(PDGFRA)mesenchymal stem/stromal cell(MSC)population with remarkable odontogenic potential.Interestingly,a reciprocal paracrine interaction between PDGFRA^(+)dental follicle stem cells(DFSCs)and CD31^(+)Endomucin^(+)endothelial cells(ECs)was mediated by Vascular endothelial growth factor A(VEGFA)and Platelet-derived growth factor subunit BB(PDGFBB).This crosstalk not only maintains the functionality of PDGFRA^(+)DFSCs but also drives specialized angiogenesis.In vivo periodontal bone regeneration experiments further reveal that communication between PDGFRA+DFSC aggregates and recipient ECs is essential for effective angiogenic-osteogenic coupling and rapid tissue repair.Collectively,our results unravel the importance of MSC-EC crosstalk mediated by the VEGFA and PDGFBB-PDGFRA reciprocal signaling in orchestrating angiogenesis and osteogenesis.These findings not only establish a framework for deciphering and promoting periodontal bone regeneration in potential clinical applications but also offer insights for future therapeutic strategies in dental or broader regenerative medicine.
文摘BACKGROUND Bone regeneration is a central focus of regenerative medicine,with applications in orthopedics and dentistry,particularly for treating bone defects caused by trauma,infection,or congenital anomalies.Synthetic biomaterials,often combined with fibrin derivatives,offer promising solutions for bone healing and restoration.AIM To Explore the increasingly important role of the association of synthetic biomaterials with fibrin in bone regeneration.METHODS Search terms included:“synthetic biomaterials AND fibrin sealant”,“hydroxyapatite AND fibrin sealant”,“tricalcium phosphate AND fibrin sealant”,and“synthetic biomaterials AND platelet-rich fibrin(PRF)”,resulting in 67 articles.After rigorous screening,21 articles met the inclusion criteria.RESULTS The reviewed studies assessed biomaterials like hydroxyapatite(HA),β-tricalcium phosphate(β-TCP),and fibrin-based products.Key findings highlighted the enhanced osteoconductivity and biocompatibility of HA andβ-TCP,especially when combined with fibrin sealants.These composites show significant potential for improving cellular adhesion,promoting osteogenic differentiation,and accelerating bone regeneration.The antimicrobial properties and structural support for cell growth of certain biomaterials indicate a promising potential for clinical applic-ations.CONCLUSION This systematic review emphasizes the growing role of fibrin-based biomaterials in bone regeneration and urges continued research to improve their clinical use for complex bone defects.
文摘Bone defects caused by trauma,infection,or congenital anomalies remain a significant challenge in orthopedic and dental practice,necessitating innovative strategies to enhance healing and functional restoration.This systematic review by Pagani et al synthesizes evidence on the synergistic role of synthetic biomaterials,such as hydroxyapatite(HA)andβ-tricalcium phosphate(β-TCP),combined with fibrin derivatives in bone regeneration.Analyzing 21 studies,the authors demonstrate that HA andβ-TCP composites exhibit superior osteoconductivity and biocompatibility when integrated with fibrin sealants or plateletrich fibrin,promoting cellular adhesion,osteogenic differentiation,and accelerated healing.While these studies underscore the potential of these biomaterialfibrin hybrids,limitations such as variability in fibrin preparation,lack of longterm data,and insufficient standardization hinder clinical translation.This editorial contextualizes these findings within the evolving landscape of regenerative medicine,emphasizing the need for optimized formulations,interdisciplinary collaboration,and robust clinical trials to bridge laboratory innovation to bedside application.
文摘BACKGROUND Exosome-based therapies represent a promising approach for hair regeneration.Unlike conventional treatments such as minoxidil and finasteride,exosomes deliver bioactive cargo that can stimulate dermal papilla cells,enhance angiogenesis,and modulate inflammatory pathways.However,variability in exosome sources,isolation techniques,and dosing protocols limits their clinical translation.AIM To synthesize findings from in vitro,preclinical and clinical studies,and to evaluate the efficacy,mechanisms,and challenges associated with exosome-based hair restoration therapies.METHODS A literature search was conducted using multiple databases(PubMed/Medline,Embase,Scopus,and Web of Science)employing terms for exosomes and hair regeneration for articles published in English to February 2025,following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.RESULTS A total of 27 studies(three in vitro,three pre-clinical,18 with both in vitro and preclinical component and three clinical)met the pre-defined search and inclusion criteria and were included in this review.CONCLUSION Exosome-based therapies hold immense promise for hair regeneration by leveraging their ability to modulate key signaling pathways and enhance hair follicle regeneration.While in vitro and preclinical studies demonstrate consistent efficacy across diverse exosome sources,methodological heterogeneity and a limited number of clinical studies warrant further clinical research to realize their full clinical potential for hair regeneration.
文摘Bone marrow cells for the treatment of ischemic brain injury may depend on the secretion of a large number of neurotrophic factors. Bone marrow regenerative cells are capable of increasing the secretion of neurotrophic factors. In this study, after tail vein injection of 5-fluorouracil for 7 days, bone marrow cells and bone marrow regenerative cells were isolated from the tibias and femurs of rats, and then administered intravenously via the tail vein after focal cerebral ischemia. Immunohistological staining and reverse transcription-PCR detection showed that transplanted bone marrow cells and bone marrow regenerative cells could migrate and survive in the ischemic regions, such as the cortical and striatal infarction zone. These cells promote vascular endothelial cell growth factor mRNA expression in the ischemic marginal zone surrounding the ischemic penumbra of the cortical and striatal infarction zone, and have great advantages in promoting the recovery of neurological function, reducing infarct size and promoting angiogenesis. Bone marrow regenerative cells exhibited stronger neuroprotective effects than bone marrow cells. Our experimental findings indicate that bone marrow regenerative cells are preferable over bone marrow cells for cell therapy for neural regeneration after cerebral ischemia. Their neuroprotective effect is largely due to their ability to induce the secretion of factors that promote vascular regeneration, such as vascular endothelial growth factor.
基金supported by the National Natural Science Foundation of China(Nos.52325504,52235007,and T2121004).
文摘As surgical procedures transition from conventional resection to advanced tissue-regeneration technologies,human disease therapy has witnessed a great leap forward.In particular,three-dimensional(3D)bioprinting stands as a landmark in this setting,by promising the precise integration of biomaterials,cells,and bioactive molecules,thus opening up a novel avenue for tissue/organ regeneration.Curated by the editorial board of Bio-Design and Manufacturing,this review brings together a cohort of leading young scientists in China to dissect the core functionalities and evolutionary trajectory of 3D bioprinting,by elucidating the intricate challenges encountered in the manufacturing of transplantable organs.We further delve into the translational pathway from scientific research to clinical application,emphasizing the imperativeness of establishing a regulatory framework and rigorously enforcing quality-control measures.Finally,this review outlines the strategic landscape and innovative achievements of China in this field and provides a comprehensive roadmap for researchers worldwide to propel this field collectively to even greater heights.
基金supported by the National Natural Science Foundation of China(Nos.52107126 and52077179)the Key Regional Innovation and Development Joint Fund Project(No.2023YFB2303901)the funding of Chengdu Guojia Electrical Engineering Co.,Ltd.(No.NEEC-2022-B11).
文摘The regenerative braking energy utilization system(RBEUS)stands as a promising technique for improving the efficiency and power quality of electrified railways.Beyond the vital aspects of energy management and control strategies,ensuring fault protection is paramount for the secure and steady operation of the traction power supply system(TPSS)integrated with RBEUS.This paper introduces an innovative protection scheme tailored to diverse RBEUS application scenarios.Firstly,fault categories are streamlined into three levels:system,equipment,and warning.Subsequently,a novel multi-port active power differential protection method,aligned with RBEUS operational principles,is crafted to serve as a comprehensive and sensitive main protection.Building upon this foundation,a hierarchical protection structure for RBEUS is established,addressing the intricacies and variations in fault types while boosting anti-disturbance capabilities under faulty conditions.Embracing the principle of railway-oriented safety,a collaborative RBEUS-TPSS protection scheme is put forth.Finally,through simulated scenarios encompassing various fault conditions,the proposed scheme’s feasibility and effectiveness are convincingly validated.
文摘Due to the complex high-temperature characteristics of hydrocarbon fuel,the research on the long-term working process of parallel channel structure under variable working conditions,especially under high heat-mass ratio,has not been systematically carried out.In this paper,the heat transfer and flow characteristics of related high temperature fuels are studied by using typical engine parallel channel structure.Through numeri⁃cal simulation and systematic experimental verification,the flow and heat transfer characteristics of parallel chan⁃nels under typical working conditions are obtained,and the effectiveness of high-precision calculation method is preliminarily established.It is known that the stable time required for hot start of regenerative cooling engine is about 50 s,and the flow resistance of parallel channel structure first increases and then decreases with the in⁃crease of equivalence ratio(The following equivalence ratio is expressed byΦ),and there is a flow resistance peak in the range ofΦ=0.5~0.8.This is mainly caused by the coupling effect of high temperature physical proper⁃ties,flow rate and pressure of fuel in parallel channels.At the same time,the cooling and heat transfer character⁃istics of parallel channels under some conditions of high heat-mass ratio are obtained,and the main factors affect⁃ing the heat transfer of parallel channels such as improving surface roughness and strengthening heat transfer are mastered.In the experiment,whenΦis less than 0.9,the phenomenon of local heat transfer enhancement and deterioration can be obviously observed,and the temperature rise of local structures exceeds 200℃,which is the risk of structural damage.Therefore,the reliability of long-term parallel channel structure under the condition of high heat-mass ratio should be fully considered in structural design.
基金support from the Ministry of Higher Education Malaysia under grant HICOE-2023-005.
文摘A unitized regenerative fuel cell(URFC)is a device that may function reversibly as either a fuel cell(FC)or water elec-trolysis(WE).An important component of this device is the Membrane electrode assembly(MEA).Therefore,this study aimed to compare the performance outcomes of MEA using electrodes with single and three catalyst layers.This study measured Electrochemical Surface Area(ECSA),Electrochemical Impedance Spectroscopy(EIS),X-ray Diffraction analysis(XRD),and X-ray Fluorescence(XRF).Furthermore,the round-trip efficiency(RTE)of the MEA,as w ell as the performance in FC and WE mode,was measured.In comparison,The ECSA values of Pt-Ru/C and Pt/C with three catalyst layers were higher than the single catalyst layer.This result was supported by electrode characterization data for XRD and XRF.The respective electrical conductivity values of Pt-Ru/C and Pt/C with three catalyst layers are also higher than the single cata-lyst layer,and the performance of URFC using MEA with three catalyst layers has the highest value of RTE among the MEA performances of URFC,which is 100%at a current density of 4 mA·cm-2.
基金supported by grants from the National Natural Science Foundation of China(81970771)Project supported by the Natural Science Foundation of Fujian Province,China(2020D027).
文摘Conjunctival goblet cells are of great significance to the ocular surface.By secreting mucins-particularly MUC5AC-they play a pivotal role in stabilizing the tear film,safeguarding the cornea from environmental insults,and preserving overall ocular homeostasis.Over the past decade,remarkable progress has been made in understanding the distinctive biological characteristics and regenerative potential of these specialized cells,opening novel avenues for treating various ocular surface disorders,ranging from dry eye syndrome and allergic conjunctivitis to more severe conditions such as Stevens-Johnson syndrome.This review comprehensively examines the morphology,function,and regulation of conjunctival goblet cells.Advanced imaging modalities,such as transmission electron microscopy,have provided in-depth insights into their ultrastructure.Densely packed mucin granules and a specialized secretory apparatus have been uncovered,highlighting the cells’proficiency in producing and releasing MUC5AC.These structural characterizations have significantly enhanced our understanding of how goblet cells contribute to maintaining a stable and protective mucosal barrier,which is crucial for ocular surface integrity.The review further delves into the intricate signaling networks governing the differentiation and regeneration of these cells.Key pathways,including Notch,Wnt/β-catenin,and TGF-β,have emerged as essential regulators of cell fate decisions,ensuring that goblet cells maintain their specialized functions.Critical transcription factors,such as Klf4,Klf5,and SPDEF,have been identified as indispensable for driving the differentiation process and sustaining the mature phenotype of goblet cells.Additionally,the modulatory effects of inflammatory mediators-such as IL-6,IL-13,and TNF-α-and growth factors,such as EGF and FGF,are explored.These molecular insights offer a robust framework for understanding the pathophysiological mechanisms underlying ocular surface diseases,wherein the dysregulation of these processes often results in diminished goblet cell numbers and impaired tear film stability.Innovative methodological approaches have provided a strong impetus to this field.The development of three-dimensional(3D)in vitro culture systems that replicate the native conjunctival microenvironment has enabled more physiologically relevant investigations of goblet cell biology.Moreover,the integration of stem cell technologies-including the use of induced pluripotent stem cells(iPSCs)and bone marrow-derived mesenchymal stem cells(BM-MSCs)-has made it possible to generate goblet cell-like epithelia,thereby presenting promising strategies for tissue engineering and regenerative therapies.The application of artificial intelligence in optimizing drug screening and biomaterial scaffold design represents an exciting frontier that may accelerate the translation of these findings into effective clinical interventions.In conclusion,this review underscores the central role of conjunctival goblet cells in preserving ocular surface health and illuminates the transformative potential of emerging regenerative approaches.Continued research focused on deciphering the intricate molecular mechanisms governing goblet cell function and regeneration is essential for developing innovative,targeted therapies that can significantly improve the management of ocular surface diseases and enhance patient quality of life.
基金supported by the Key project of Hunan Provincial Education Department(Grant Number:22A0485)The Natural Science Foundation of Hunan(Grant Number:2024JJ5293)The Key project of Hunan University of Arts and Science(Grant Number:23ZZ08).
文摘In liquid rocket engines,regenerative cooling technology is essential for preserving structural integrity under extreme thermal loads.However,non-uniform coolant flow distribution within the cooling channels often leads to localized overheating,posing serious risks to engine reliability and operational lifespan.This study employs a three-dimensional fluid–thermal coupled numerical model to systematically investigate the influence of geometric parameters-specifically the number of inlets,the number of channels,and inlet manifold configurations-on flow uniformity and thermal distribution in non-pyrolysis zones.Key findings reveal that increasing the number of inlets from one to three significantly enhances flow uniformity,reducing mass flow rate deviation from 1.2%to below 0.3%.However,further increasing the inlets to five yields only marginal improvements indicating diminishing(<0.1%),returns beyond three inlets.Additionally,temperature non-uniformity at the combustion chamber throat decreases by 37%-from 3050 K with 18 channels to 1915 K with 30 channels-highlighting the critical role of channel density in effective thermal regulation.Notably,while higher channel counts improve cooling efficiency,they also result in increased pressure losses of approximately 18%–22%,emphasizing the need to balance thermal performance against hydraulic resistance.An optimal configuration comprising 24 channels and three inlets was identified,providing minimal temperature gradients while maintaining acceptable pressure losses.The inlet manifold structure also plays a pivotal role in determining flow distribution.Configuration 3(Config-3),which features an enlarged manifold and reduced inlet velocity,achieves a 40%reduction in velocity fluctuations compared to Configuration 1(Config-1).This improvement leads to a more uniform mass flow distribution,with a relative standard deviation(RSD)of less than 0.15%.Furthermore,this design effectively mitigates localized hot spots near the nozzle-where temperature gradients are most severe-achieving a reduction of approximately 1135 K.
