Exogenous neural stem cell transplantation has become one of the most promising treatment methods for chronic stroke.Recent studies have shown that most ischemia-reperfusion model rats recover spontaneously after inju...Exogenous neural stem cell transplantation has become one of the most promising treatment methods for chronic stroke.Recent studies have shown that most ischemia-reperfusion model rats recover spontaneously after injury,which limits the ability to observe long-term behavioral recovery.Here,we used a severe stroke rat model with 150 minutes of ischemia,which produced severe behavioral deficiencies that persisted at 12 weeks,to study the therapeutic effect of neural stem cells on neural restoration in chronic stroke.Our study showed that stroke model rats treated with human neural stem cells had long-term sustained recovery of motor function,reduced infarction volume,long-term human neural stem cell survival,and improved local inflammatory environment and angiogenesis.We also demonstrated that transplanted human neural stem cells differentiated into mature neurons in vivo,formed stable functional synaptic connections with host neurons,and exhibited the electrophysiological properties of functional mature neurons,indicating that they replaced the damaged host neurons.The findings showed that human fetal-derived neural stem cells had long-term effects for neurological recovery in a model of severe stroke,which suggests that human neural stem cells-based therapy may be effective for repairing damaged neural circuits in stroke patients.展开更多
BACKGROUND Meniscal sparing surgery is a widely utilised treatment option for unstable meniscal tears with the aim of minimising the risk of progression towards osteoarthritis.However,there is limited data in the lite...BACKGROUND Meniscal sparing surgery is a widely utilised treatment option for unstable meniscal tears with the aim of minimising the risk of progression towards osteoarthritis.However,there is limited data in the literature on meniscal repair outcomes in skeletally immature patients.AIM To evaluate the re-operation rate and functional outcomes of meniscal repairs in children and adolescents.METHODS We performed a retrospective review of all patients who underwent arthroscopic meniscal repair surgery between January 2007 and January 2018.All patients were under the age of 18 at the time of surgery.Procedures were all performed by a single surgeon.Information was gathered from our hospital Electronic Patient Records system.The primary outcome measure was re-operation rate(need for further surgery on the same meniscus).Secondary outcome measures were surgical complications and patient reported outcome measures that were International Knee Documentation Committee(IKDC),Tegner and Lysholm scores.RESULTS We identified 59 patients who underwent 66 All-inside meniscal repairs(32 medial meniscus and 34 Lateral meniscus).Meniscal repairs were performed utilizing FasT-Fix(Smith and Nephew)implants.There were 37 males and 22 females with an average age of 14 years(range 6-16).The average follow-up time was 53 months(range 26-140).Six patients had concomitant anterior cruciate ligament reconstruction surgery along with the meniscal repair.There were no requiring further meniscal repairs and 9 patients underwent partial meniscectomies.The mean postoperative IKDC score was 88(44-100),Tegner score was 7(2-10)and Lysholm score was 94(57-100).CONCLUSION Our results showed that arthroscopic repair of meniscal tears in the paediatric population is an effective treatment option that has a low failure rate and good postoperative clinical with the advantage of preserving meniscal tissues.展开更多
With attractive research and development of biomaterials, more and more opportunities have been brought to the treatments of human tissue repairs. The implant is usually no need to exist in the body accompanied with t...With attractive research and development of biomaterials, more and more opportunities have been brought to the treatments of human tissue repairs. The implant is usually no need to exist in the body accompanied with the recovery or regeneration of the tissue lesions, and the long-term effect of exotic substance to human body should be reduced as lower as possible. For this purpose, biodegradable materials, including polymers, magnesium alloys and ceramics, have attracted much attention for medical applications due to their biodegradable characters in body environment. This paper in turn introduces these three different types of widely studied biodegradable materials as well as their advantages as implants in applications for bone repairs. Relevant history and research progresses are summarized.展开更多
Repairing effect of fly ash （FA） on damage of recycled coarse aggregate was evaluated by characteristics of pores and cracks in the vicinity of interracial transition zone （ITZ）. The interracial structure between ...Repairing effect of fly ash （FA） on damage of recycled coarse aggregate was evaluated by characteristics of pores and cracks in the vicinity of interracial transition zone （ITZ）. The interracial structure between the virgin aggregate and the attached old mortar was investigated and compared with ITZ of recycled aggregate concrete in the presence of FA or ultra-fine FA（UFA） by means of scanning electron microscope （SEM）. Diameter and plumpness frequency distribution of pores as well as width of the old ITZ, length of contacting points and cracks density were analyzed. The SEM results reveal that the diameter of pores is decreases significantly but pores plumpness increases. A decreased ITZ width and cracks density as well as an increased bonding zone length can also been observed, which indicates that FA or UFA repairs damage of recycled coarse aggregate due to its granular effect.展开更多
Veins are easy to obtain,have low immunogenicity,and induce a relatively weak inflammatory response.Therefore,veins have the potential to be used as conduits for nerve regeneration.However,because of the presence of v...Veins are easy to obtain,have low immunogenicity,and induce a relatively weak inflammatory response.Therefore,veins have the potential to be used as conduits for nerve regeneration.However,because of the presence of venous valves and the great elasticity of the venous wall,the vein is not conducive to nerve regeneration.In this study,a novel tissue engineered nerve graft was constructed by combining normal dissected nerve microtissue with an autologous vein graft for repairing 10-mm peripheral nerve defects in rats.Compared with rats given the vein graft alone,rats given the tissue engineered nerve graft had an improved sciatic static index,and a higher amplitude and shorter latency of compound muscle action potentials.Furthermore,rats implanted with the microtissue graft had a higher density and thickness of myelinated nerve fibers and reduced gastrocnemius muscle atrophy compared with rats implanted with the vein alone.However,the tissue engineered nerve graft had a lower ability to repair the defect than autogenous nerve transplantation.In summary,although the tissue engineered nerve graft constructed with autologous vein and nerve microtissue is not as effective as autologous nerve transplantation for repairing long-segment sciatic nerve defects,it may nonetheless have therapeutic potential for the clinical repair of long sciatic nerve defects.This study was approved by the Experimental Animal Ethics Committee of Chinese PLA General Hospital(approval No.2016-x9-07)on September 7,2016.展开更多
The use of reporter systems to analyze DNA double-strand break（DSB） repairs,based on the enhanced green fluorescent protein （EGFP） and meganuclease such as I-Sce I,is usually carried out with cell lines.In this st...The use of reporter systems to analyze DNA double-strand break（DSB） repairs,based on the enhanced green fluorescent protein （EGFP） and meganuclease such as I-Sce I,is usually carried out with cell lines.In this study,we developed three visual-plus quantitative assay systems for homologous recombination（HR）,non-homologous end joining（NHEJ） and single-strand annealing（SSA） DSB repair pathways at the organismal level in zebrafish embryos.To initiate DNA DSB repair,we used two I-Sce I recognition sites in opposite orientation rather than the usual single site.The NHEJ,HR and SSA repair pathways were separately triggered by the injection of three corresponding I-Sce I-cut constructions,and the repair of DNA lesion caused by l-Sce I could be tracked by EGFP expression in the embryos.Apart from monitoring the intensity of green fluorescence,the repair frequencies could also be precisely measured by quantitative real-time polymerase chain reaction（qPCR）.Analysis of DNA sequences at the DSB sites showed that NHEJ was predominant among these three repair pathways in zebrafish embryos.Furthermore,while HR and SSA reporter systems could be effectively decreased by the knockdown of rad51 and rad52,respectively,NHEJ could only be impaired by the knockdown of ligaseIV（lig4） when the NHEJ construct was cut by I-Sce I in vivo.More interestingly,blocking NHEJ with lig4-MO increased the frequency of HR,but decreased the frequency of SSA.Our studies demonstrate that the major mechanisms used to repair DNA DSBs are conserved from zebrafish to mammal,and zebrafish provides an excellent model for studying and manipulating DNA DSB repair at the organismal level.展开更多
The aim of this work is to study the influence of successive weld repairs on the microstructure and the mechanical behavior of the heat-affected zone（HAZ） of an HSLA X70 steel. Detailed microstructural examination c...The aim of this work is to study the influence of successive weld repairs on the microstructure and the mechanical behavior of the heat-affected zone（HAZ） of an HSLA X70 steel. Detailed microstructural examination combined to grain size measurement showed that beyond the second weld repair, the microstructure of the HAZ undergoes significant change in the grain morphology and grain growth. The results of the X-ray diffraction analyzed using MAUD software indicated an increase in the crystallite size and a decrease in the dislocation density according to the number of weld repair operations. Consequently, a loss of mechanical properties, namely the yield strength and the toughness with the number of weld repairs, was recorded. Beyond the second weld repair operation, the properties of the welded joint do not fulfill the standards applied in piping industry.展开更多
This study compares the changes of DNA repair in brain tissue dominated by the middle cerebral artery after electroacupuncture at the acupoints of Renzhong （DU 26）, Neiguan （PC 6）, Quchi （LI 11） and Zusanli （ST...This study compares the changes of DNA repair in brain tissue dominated by the middle cerebral artery after electroacupuncture at the acupoints of Renzhong （DU 26）, Neiguan （PC 6）, Quchi （LI 11） and Zusanli （ST 36） in rats. In the apurinic/apyrimidinic endonuclease DNA basic group reparative excision experiments, the apurinic/apyrimidinic endonuclease activity of brain tissue increased slightly after electroacupuncture in rats. In the DNA polymerase β （Pol β）experiments, the Pol β ac-tivity of brain tissue increased after electroacupuncture, especially at DU 26 and PC 6. In the DNA ligase experiments, the expression of DNA ligase 1 in brain tissue increased significantly after electroacupuncture. These findings demonstrate increased activity of apurinic/apyrimidinic en-donuclease, Pol β and DNA ligase 1 after electroacupuncture at DU 26 and PC 6. Also, DNA repair in brain tissue supplied by the middle cerebral artery is promoted after electroacupuncture at DU 26 and PC 6, which are more effective than the LI 11 and ST 36 acupoints .展开更多
The paper deals with temporary repairs. Applying a different technology, using a reproduction part, or performing a repair by a serviceman without the competence is typical features of temporary repairs. Temporary rep...The paper deals with temporary repairs. Applying a different technology, using a reproduction part, or performing a repair by a serviceman without the competence is typical features of temporary repairs. Temporary repair makes possible for an object to fulfil its function for a limited time, until regular repairs can be made. The complexity perplex modern vehicles their reparability. It is necessary to look for the new procedures of the implementation so-called temporary repairs. The authors suggested procedure battle damage assessment and repair, which they expressed in the form of diagrams. There is also description of new technological procedures, which could be possibly applied in field of temporary repairs. These new procedures are applied on land (wheeled and tracked) vehicles parts and their sufficiency for Czech Army conditions is tested. The main purpose of the thesis is defining operating procedures of the most useful methods, including their verifications and proposal of tools needed for repairs. These tools should be included in equipment of vehicles operated in Czech Army. The thesis is primarily focused on repairs of mechanical parts and units and also of reparation of fuel, hydraulic and high pressure systems.展开更多
I consider a system whose deterioration follows a discrete-time and discrete-state Markov chain with an absorbing state. When the system is put into practice, I may select operation (wait), imperfect repair, or replac...I consider a system whose deterioration follows a discrete-time and discrete-state Markov chain with an absorbing state. When the system is put into practice, I may select operation (wait), imperfect repair, or replacement at each discrete-time point. The true state of the system is not known when it is operated. Instead, the system is monitored after operation and some incomplete information concerned with the deterioration is obtained for decision making. Since there are multiple imperfect repairs, I can select one option from them when the imperfect repair is preferable to operation and replacement. To express this situation, I propose a POMDP model and theoretically investigate the structure of an optimal maintenance policy minimizing a total expected discounted cost for an unbounded horizon. Then two stochastic orders are used for the analysis of our problem.展开更多
1 Introduction Compared with retraining,fine-tuning,and other traditional approaches,neural network repair approaches[1-7]can significantly improve the robustness of neural networks with lower time and computing cost....1 Introduction Compared with retraining,fine-tuning,and other traditional approaches,neural network repair approaches[1-7]can significantly improve the robustness of neural networks with lower time and computing cost.These repair techniques encode the anticipated performance of the repaired neural network into a Satisfiability Modulo Theories(SMT)problem and utilize an SMT solver to calculate a parameter matrix for the fully connected layer.This matrix can then be multiplied with the example feature vector to yield a vector that satisfies predetermined conditions.展开更多
The authors of the article titled“Late chordee correction after tubularized incised plate repair for proximal hypospadias:An underreported problem”published in UroPrecision in 2024[1],should be congratulated for pre...The authors of the article titled“Late chordee correction after tubularized incised plate repair for proximal hypospadias:An underreported problem”published in UroPrecision in 2024[1],should be congratulated for presenting an important yet underreported complication of treating proximal hypospadias with techniques preserving the urethral plate(UP),essentially tubularized incised plate(TIP)repair in this report.There are several important aspects of hypospadias repair that need to be highlighted in this context.展开更多
Reliability-redundancy allocation,preventive maintenance,and spare parts logistics are crucial for achieving system reliability and availability goal.Existing methods often concentrate on specific scopes of the system...Reliability-redundancy allocation,preventive maintenance,and spare parts logistics are crucial for achieving system reliability and availability goal.Existing methods often concentrate on specific scopes of the system’s lifetime.This paper proposes a joint redundancymaintenance-inventory allocation model that simultaneously optimizes redundant component,replacement time,spares stocking,and repair capacity.Under reliability and availability criteria,our objective is to minimize the system’s lifetime cost,including design,manufacturing,and operational phases.We develop a unified system availability model based on ten performance drivers,serving as the foundation for the establishment of the lifetimebased resource allocation model.Superimposed renewal theory is employed to estimate spare part demand from proactive and corrective replacements.A bisection algorithm,enhanced by neighborhood exploration,solves the complex mixed-integer,nonlinear optimization problem.The numerical experiments show that component redundancy is preferred and necessary if one of the following situations occurs:extremely high system availability is required,the fleet size is small,the system reliability is immature,the inventory holding is too costly,or the handson replacement time is prolonged.The joint allocation model also reveals that there exists no monotonic relation between spares stocking level and system availability.展开更多
Overview of the DNA damage response(DDR)in tumor cells.DDR is a highly coordinated signaling network that repairs DNA damage caused by intrinsic cellular processes and extrinsic insults,thereby preventing genome insta...Overview of the DNA damage response(DDR)in tumor cells.DDR is a highly coordinated signaling network that repairs DNA damage caused by intrinsic cellular processes and extrinsic insults,thereby preventing genome instability.Depending on the type of damage,distinct DNA damage repair and DNA damage tolerance(DDT)pathways are involved and coordinately regulated.展开更多
CD47 is a ubiquitous and pleiotropic cell-surface receptor.Disrupting CD47 enhances injury repair in various tissues but the role of CD47 has not been studied in bone injuries.In a murine closed-fracture model,CD47-nu...CD47 is a ubiquitous and pleiotropic cell-surface receptor.Disrupting CD47 enhances injury repair in various tissues but the role of CD47 has not been studied in bone injuries.In a murine closed-fracture model,CD47-null mice showed decreased callus bone formation as assessed by microcomputed tomography 10 days post-fracture and increased fibrous volume as determined by histology.To understand the cellular basis for this phenotype,mesenchymal progenitors(MSC)were harvested from bone marrow.CD47-null MSC showed decreased large fibroblast colony formation(CFU-F),significantly less proliferation,and fewer cells in Sphase,although osteoblast differentiation was unaffected.However,consistent with prior research,CD47-null endothelial cells showed increased proliferation relative to WT cells.Similarly,in a murine ischemic fracture model,CD47-null mice showed reduced fracture callus size due to a reduction in bone relative to WT 15 days-post fracture.Consistent with our in vitro results,in vivo EdU labeling showed decreased cell proliferation in the callus of CD47-null mice,while staining for CD31 and endomucin demonstrated increased endothelial cell density.Finally,WT mice with ischemic fracture that were administered a CD47 morpholino,which blocks CD47 protein production,showed a callus phenotype similar to that of ischemic fractures in CD47-null mice,suggesting the phenotype was not due to developmental changes in the knockout mice.Thus,inhibition of CD47 during bone healing reduces both non-ischemic and ischemic fracture healing,in part,by decreasing MSC proliferation.Furthermore,the increase in endothelial cell proliferation and early blood vessel density caused by CD47 disruption is not sufficient to overcome MSC dysfunction.展开更多
In the mammalian central nervous system(CNS),astrocytes are the ubiquitous glial cells that have complex morphological and molecular characteristics.These fascinating cells play essential neurosupportive and homeostat...In the mammalian central nervous system(CNS),astrocytes are the ubiquitous glial cells that have complex morphological and molecular characteristics.These fascinating cells play essential neurosupportive and homeostatic roles in the healthy CNS and undergo morphological,molecular,and functional changes to adopt so-called‘reactive’states in response to CNS injury or disease.In recent years,interest in astrocyte research has increased dramatically and some new biological features and roles of astrocytes in physiological and pathological conditions have been discovered thanks to technological advances.Here,we will review and discuss the wellestablished and emerging astroglial biology and functions,with emphasis on their potential as therapeutic targets for CNS injury,including traumatic and ischemic injury.This review article will highlight the importance of astrocytes in the neuropathological process and repair of CNS injury.展开更多
BACKGROUND Skin wounds are common injuries that affect quality of life and incur high costs.A considerable portion of healthcare resources in Western countries is allocated to wound treatment,mainly using mechanical,b...BACKGROUND Skin wounds are common injuries that affect quality of life and incur high costs.A considerable portion of healthcare resources in Western countries is allocated to wound treatment,mainly using mechanical,biological,or artificial dressings.Biological and artificial dressings,such as hydrogels,are preferred for their biocompatibility.Platelet concentrates,such as platelet-rich plasma(PRP)and platelet-rich fibrin(PRF),stand out for accelerating tissue repair and minimizing risks of allergies and rejection.This study developed PRF and PRP-based dressings to treat skin wounds in an animal model,evaluating their functionality and efficiency in accelerating the tissue repair process.AIM To develop wound dressings based on platelet concentrates and evaluating their efficiency in treating skin wounds in Wistar rats.METHODS Wistar rats,both male and female,were subjected to the creation of a skin wound,distributed into groups(n=64/group),and treated with Carbopol(negative control);PRP+Carbopol;PRF+Carbopol;or PRF+CaCl_(2)+Carbopol,on days zero(D0),D3,D7,D14,and D21.PRP and PRF were obtained only from male rats.On D3,D7,D14,and D21,the wounds were analyzed for area,contraction rate,and histopathology of the tissue repair process.RESULTS The PRF-based dressing was more effective in accelerating wound closure early in the tissue repair process(up to D7),while PRF+CaCl_(2) seemed to delay the process,as wound closure was not complete by D21.Regarding macroscopic parameters,animals treated with PRF+CaCl_(2) showed significantly more crusting(necrosis)early in the repair process(D3).In terms of histopathological parameters,the PRF group exhibited significant collagenization at the later stages of the repair process(D14 and D21).By D21,fibroblast proliferation and inflammatory infiltration were higher in the PRP group.Animals treated with PRF+CaCl_(2) experienced a more pronounced inflammatory response up to D7,which diminished from D14 onwards.CONCLUSION The PRF-based dressing was effective in accelerating the closure of cutaneous wounds in Wistar rats early in the process and in aiding tissue repair at the later stages.展开更多
Objective:Triple-negative breast cancer(TNBC)is a highly aggressive subtype that lacks targeted therapies,leading to a poorer prognosis.However,some patients achieve long-term recurrence-free survival(RFS),offering va...Objective:Triple-negative breast cancer(TNBC)is a highly aggressive subtype that lacks targeted therapies,leading to a poorer prognosis.However,some patients achieve long-term recurrence-free survival(RFS),offering valuable insights into tumor biology and potential treatment strategies.Methods:We conducted a comprehensive multi-omics analysis of 132 patients with American Joint Committee on Cancer(AJCC)stage III TNBC,comprising 36 long-term survivors(RFS≥8 years),62 moderate-term survivors(RFS:3-8 years),and 34 short-term survivors(RFS<3 years).Analyses investigated clinicopathological factors,whole-exome sequencing,germline mutations,copy number alterations(CNAs),RNA sequences,and metabolomic profiles.Results:Long-term survivors exhibited fewer metastatic regional lymph nodes,along with tumors showing reduced stromal fibrosis and lower Ki67 index.Molecularly,these tumors exhibited multiple alterations in genes related to homologous recombination repair,with higher frequencies of germline mutations and somatic CNAs.Additionally,tumors from long-term survivors demonstrated significant downregulation of the RTK-RAS signaling pathway.Metabolomic profiling revealed decreased levels of lipids and carbohydrate,particularly those involved in glycerophospholipid,fructose,and mannose metabolism,in long-term survival group.Multivariate Cox analysis identified fibrosis[hazard ratio(HR):12.70,95%confidence interval(95%CI):2.19-73.54,P=0.005]and RAC1copy number loss/deletion(HR:0.22,95%CI:0.06-0.83,P=0.026)as independent predictors of RFS.Higher fructose/mannose metabolism was associated with worse overall survival(HR:1.30,95%CI:1.01-1.68,P=0.045).Our findings emphasize the association between biological determinants and prolonged survival in patients with TNBC.Conclusions:Our study systematically identified the key molecular and metabolic features associated with prolonged survival in AJCC stage III TNBC,suggesting potential therapeutic targets to improve patient outcomes.展开更多
The global demand for effective skin injury treatments has prompted the exploration of tissue engineering solutions.While three-dimensional(3D)bioprinting has shown promise,challenges persist with respect to achieving...The global demand for effective skin injury treatments has prompted the exploration of tissue engineering solutions.While three-dimensional(3D)bioprinting has shown promise,challenges persist with respect to achieving timely and compatible solutions to treat diverse skin injuries.In situ bioprinting has emerged as a key new technology,since it reduces risks during the implantation of printed scaffolds and demonstrates superior therapeutic effects.However,maintaining printing fidelity during in situ bioprinting remains a critical challenge,particularly with respect to model layering and path planning.This study proposes a novel optimization-based conformal path planning strategy for in situ bioprinting-based repair of complex skin injuries.This strategy employs constrained optimization to identify optimal waypoints on a point cloud-approximated curved surface,thereby ensuring a high degree of similarity between predesigned planar and surface-mapped 3D paths.Furthermore,this method is applicable for skin wound treatments,since it generates 3D-equidistant zigzag curves along surface tangents and enables multi-layer conformal path planning to facilitate the treatment of volumetric injuries.Furthermore,the proposed algorithm was found to be a feasible and effective treatment in a murine back injury model as well as in other complex models,thereby showcasing its potential to guide in situ bioprinting,enhance bioprinting fidelity,and facilitate improvement of clinical outcomes.展开更多
Neuronal growth, extension, branching, and formation of neural networks are markedly influenced by the extracellular matrix—a complex network composed of proteins and carbohydrates secreted by cells. In addition to p...Neuronal growth, extension, branching, and formation of neural networks are markedly influenced by the extracellular matrix—a complex network composed of proteins and carbohydrates secreted by cells. In addition to providing physical support for cells, the extracellular matrix also conveys critical mechanical stiffness cues. During the development of the nervous system, extracellular matrix stiffness plays a central role in guiding neuronal growth, particularly in the context of axonal extension, which is crucial for the formation of neural networks. In neural tissue engineering, manipulation of biomaterial stiffness is a promising strategy to provide a permissive environment for the repair and regeneration of injured nervous tissue. Recent research has fine-tuned synthetic biomaterials to fabricate scaffolds that closely replicate the stiffness profiles observed in the nervous system. In this review, we highlight the molecular mechanisms by which extracellular matrix stiffness regulates axonal growth and regeneration. We highlight the progress made in the development of stiffness-tunable biomaterials to emulate in vivo extracellular matrix environments, with an emphasis on their application in neural repair and regeneration, along with a discussion of the current limitations and future prospects. The exploration and optimization of the stiffness-tunable biomaterials has the potential to markedly advance the development of neural tissue engineering.展开更多
文摘Exogenous neural stem cell transplantation has become one of the most promising treatment methods for chronic stroke.Recent studies have shown that most ischemia-reperfusion model rats recover spontaneously after injury,which limits the ability to observe long-term behavioral recovery.Here,we used a severe stroke rat model with 150 minutes of ischemia,which produced severe behavioral deficiencies that persisted at 12 weeks,to study the therapeutic effect of neural stem cells on neural restoration in chronic stroke.Our study showed that stroke model rats treated with human neural stem cells had long-term sustained recovery of motor function,reduced infarction volume,long-term human neural stem cell survival,and improved local inflammatory environment and angiogenesis.We also demonstrated that transplanted human neural stem cells differentiated into mature neurons in vivo,formed stable functional synaptic connections with host neurons,and exhibited the electrophysiological properties of functional mature neurons,indicating that they replaced the damaged host neurons.The findings showed that human fetal-derived neural stem cells had long-term effects for neurological recovery in a model of severe stroke,which suggests that human neural stem cells-based therapy may be effective for repairing damaged neural circuits in stroke patients.
文摘BACKGROUND Meniscal sparing surgery is a widely utilised treatment option for unstable meniscal tears with the aim of minimising the risk of progression towards osteoarthritis.However,there is limited data in the literature on meniscal repair outcomes in skeletally immature patients.AIM To evaluate the re-operation rate and functional outcomes of meniscal repairs in children and adolescents.METHODS We performed a retrospective review of all patients who underwent arthroscopic meniscal repair surgery between January 2007 and January 2018.All patients were under the age of 18 at the time of surgery.Procedures were all performed by a single surgeon.Information was gathered from our hospital Electronic Patient Records system.The primary outcome measure was re-operation rate(need for further surgery on the same meniscus).Secondary outcome measures were surgical complications and patient reported outcome measures that were International Knee Documentation Committee(IKDC),Tegner and Lysholm scores.RESULTS We identified 59 patients who underwent 66 All-inside meniscal repairs(32 medial meniscus and 34 Lateral meniscus).Meniscal repairs were performed utilizing FasT-Fix(Smith and Nephew)implants.There were 37 males and 22 females with an average age of 14 years(range 6-16).The average follow-up time was 53 months(range 26-140).Six patients had concomitant anterior cruciate ligament reconstruction surgery along with the meniscal repair.There were no requiring further meniscal repairs and 9 patients underwent partial meniscectomies.The mean postoperative IKDC score was 88(44-100),Tegner score was 7(2-10)and Lysholm score was 94(57-100).CONCLUSION Our results showed that arthroscopic repair of meniscal tears in the paediatric population is an effective treatment option that has a low failure rate and good postoperative clinical with the advantage of preserving meniscal tissues.
基金the financial support of the National Basic Research Program of China(973 Program, No.2012CB619101)
文摘With attractive research and development of biomaterials, more and more opportunities have been brought to the treatments of human tissue repairs. The implant is usually no need to exist in the body accompanied with the recovery or regeneration of the tissue lesions, and the long-term effect of exotic substance to human body should be reduced as lower as possible. For this purpose, biodegradable materials, including polymers, magnesium alloys and ceramics, have attracted much attention for medical applications due to their biodegradable characters in body environment. This paper in turn introduces these three different types of widely studied biodegradable materials as well as their advantages as implants in applications for bone repairs. Relevant history and research progresses are summarized.
基金The Scientific Research Fund of Hunan Provincial Education Department(No.06C113)
文摘Repairing effect of fly ash （FA） on damage of recycled coarse aggregate was evaluated by characteristics of pores and cracks in the vicinity of interracial transition zone （ITZ）. The interracial structure between the virgin aggregate and the attached old mortar was investigated and compared with ITZ of recycled aggregate concrete in the presence of FA or ultra-fine FA（UFA） by means of scanning electron microscope （SEM）. Diameter and plumpness frequency distribution of pores as well as width of the old ITZ, length of contacting points and cracks density were analyzed. The SEM results reveal that the diameter of pores is decreases significantly but pores plumpness increases. A decreased ITZ width and cracks density as well as an increased bonding zone length can also been observed, which indicates that FA or UFA repairs damage of recycled coarse aggregate due to its granular effect.
基金This work was supported by the National Natural Science Foundation of China,Nos.31771052(to YW),81671684(to YXW),81871788(to CZ)National Key Research and Development Program of China,Nos.2017YFA0104702,2017YFA0104703+3 种基金the Natural Science Foundation of Beijing of China,No.7172202(to YW)PLA Youth Training Project for Medical Science of China,No.16QNP144(to YW),the Project for Science and Technology Leader of Anhui Province of China,No.2018H177(to CZ)Funding of“Panfeng”Innovation Team Project for Scientifc Research of Yijishan Hospital,Wannan Medical College,China,No.PF2019007(to HGX)Funding of“Peak”Training Program for Scientifc Research of Yijishan Hospital,Wannan Medical College,China,No.GF2019T02(to HGX).
文摘Veins are easy to obtain,have low immunogenicity,and induce a relatively weak inflammatory response.Therefore,veins have the potential to be used as conduits for nerve regeneration.However,because of the presence of venous valves and the great elasticity of the venous wall,the vein is not conducive to nerve regeneration.In this study,a novel tissue engineered nerve graft was constructed by combining normal dissected nerve microtissue with an autologous vein graft for repairing 10-mm peripheral nerve defects in rats.Compared with rats given the vein graft alone,rats given the tissue engineered nerve graft had an improved sciatic static index,and a higher amplitude and shorter latency of compound muscle action potentials.Furthermore,rats implanted with the microtissue graft had a higher density and thickness of myelinated nerve fibers and reduced gastrocnemius muscle atrophy compared with rats implanted with the vein alone.However,the tissue engineered nerve graft had a lower ability to repair the defect than autogenous nerve transplantation.In summary,although the tissue engineered nerve graft constructed with autologous vein and nerve microtissue is not as effective as autologous nerve transplantation for repairing long-segment sciatic nerve defects,it may nonetheless have therapeutic potential for the clinical repair of long sciatic nerve defects.This study was approved by the Experimental Animal Ethics Committee of Chinese PLA General Hospital(approval No.2016-x9-07)on September 7,2016.
基金supported by the National Natural Science Foundation of China(No.30971677)the National Basic Research Program of China(973 Program)(No. 2012CB944500)the Fundamental Research Funds for the Central Universities(No.2011XZZX006)
文摘The use of reporter systems to analyze DNA double-strand break（DSB） repairs,based on the enhanced green fluorescent protein （EGFP） and meganuclease such as I-Sce I,is usually carried out with cell lines.In this study,we developed three visual-plus quantitative assay systems for homologous recombination（HR）,non-homologous end joining（NHEJ） and single-strand annealing（SSA） DSB repair pathways at the organismal level in zebrafish embryos.To initiate DNA DSB repair,we used two I-Sce I recognition sites in opposite orientation rather than the usual single site.The NHEJ,HR and SSA repair pathways were separately triggered by the injection of three corresponding I-Sce I-cut constructions,and the repair of DNA lesion caused by l-Sce I could be tracked by EGFP expression in the embryos.Apart from monitoring the intensity of green fluorescence,the repair frequencies could also be precisely measured by quantitative real-time polymerase chain reaction（qPCR）.Analysis of DNA sequences at the DSB sites showed that NHEJ was predominant among these three repair pathways in zebrafish embryos.Furthermore,while HR and SSA reporter systems could be effectively decreased by the knockdown of rad51 and rad52,respectively,NHEJ could only be impaired by the knockdown of ligaseIV（lig4） when the NHEJ construct was cut by I-Sce I in vivo.More interestingly,blocking NHEJ with lig4-MO increased the frequency of HR,but decreased the frequency of SSA.Our studies demonstrate that the major mechanisms used to repair DNA DSBs are conserved from zebrafish to mammal,and zebrafish provides an excellent model for studying and manipulating DNA DSB repair at the organismal level.
基金the Research Center in Industria Technologies(CRTI)for its financial supportMohamed Khider University,Biskra,for its help to accomplish this study
文摘The aim of this work is to study the influence of successive weld repairs on the microstructure and the mechanical behavior of the heat-affected zone（HAZ） of an HSLA X70 steel. Detailed microstructural examination combined to grain size measurement showed that beyond the second weld repair, the microstructure of the HAZ undergoes significant change in the grain morphology and grain growth. The results of the X-ray diffraction analyzed using MAUD software indicated an increase in the crystallite size and a decrease in the dislocation density according to the number of weld repair operations. Consequently, a loss of mechanical properties, namely the yield strength and the toughness with the number of weld repairs, was recorded. Beyond the second weld repair operation, the properties of the welded joint do not fulfill the standards applied in piping industry.
基金the National Basic Research Program of China (973 Program), No. 2009CB522904the National Natural Science Foundation of China, No. 81173326, 81072868, 30973802 and 81102661Supported by Open Research Fund of Zhejiang First-foremost Key Subject-Acupuncture & Moxibustion, No. ZTK2010B05
文摘This study compares the changes of DNA repair in brain tissue dominated by the middle cerebral artery after electroacupuncture at the acupoints of Renzhong （DU 26）, Neiguan （PC 6）, Quchi （LI 11） and Zusanli （ST 36） in rats. In the apurinic/apyrimidinic endonuclease DNA basic group reparative excision experiments, the apurinic/apyrimidinic endonuclease activity of brain tissue increased slightly after electroacupuncture in rats. In the DNA polymerase β （Pol β）experiments, the Pol β ac-tivity of brain tissue increased after electroacupuncture, especially at DU 26 and PC 6. In the DNA ligase experiments, the expression of DNA ligase 1 in brain tissue increased significantly after electroacupuncture. These findings demonstrate increased activity of apurinic/apyrimidinic en-donuclease, Pol β and DNA ligase 1 after electroacupuncture at DU 26 and PC 6. Also, DNA repair in brain tissue supplied by the middle cerebral artery is promoted after electroacupuncture at DU 26 and PC 6, which are more effective than the LI 11 and ST 36 acupoints .
文摘The paper deals with temporary repairs. Applying a different technology, using a reproduction part, or performing a repair by a serviceman without the competence is typical features of temporary repairs. Temporary repair makes possible for an object to fulfil its function for a limited time, until regular repairs can be made. The complexity perplex modern vehicles their reparability. It is necessary to look for the new procedures of the implementation so-called temporary repairs. The authors suggested procedure battle damage assessment and repair, which they expressed in the form of diagrams. There is also description of new technological procedures, which could be possibly applied in field of temporary repairs. These new procedures are applied on land (wheeled and tracked) vehicles parts and their sufficiency for Czech Army conditions is tested. The main purpose of the thesis is defining operating procedures of the most useful methods, including their verifications and proposal of tools needed for repairs. These tools should be included in equipment of vehicles operated in Czech Army. The thesis is primarily focused on repairs of mechanical parts and units and also of reparation of fuel, hydraulic and high pressure systems.
文摘I consider a system whose deterioration follows a discrete-time and discrete-state Markov chain with an absorbing state. When the system is put into practice, I may select operation (wait), imperfect repair, or replacement at each discrete-time point. The true state of the system is not known when it is operated. Instead, the system is monitored after operation and some incomplete information concerned with the deterioration is obtained for decision making. Since there are multiple imperfect repairs, I can select one option from them when the imperfect repair is preferable to operation and replacement. To express this situation, I propose a POMDP model and theoretically investigate the structure of an optimal maintenance policy minimizing a total expected discounted cost for an unbounded horizon. Then two stochastic orders are used for the analysis of our problem.
基金supported by the National Natural Science Foundation of China(Grant No.62132020)the Major Project of ISCAS(ISCAS-ZD-202302).
文摘1 Introduction Compared with retraining,fine-tuning,and other traditional approaches,neural network repair approaches[1-7]can significantly improve the robustness of neural networks with lower time and computing cost.These repair techniques encode the anticipated performance of the repaired neural network into a Satisfiability Modulo Theories(SMT)problem and utilize an SMT solver to calculate a parameter matrix for the fully connected layer.This matrix can then be multiplied with the example feature vector to yield a vector that satisfies predetermined conditions.
文摘The authors of the article titled“Late chordee correction after tubularized incised plate repair for proximal hypospadias:An underreported problem”published in UroPrecision in 2024[1],should be congratulated for presenting an important yet underreported complication of treating proximal hypospadias with techniques preserving the urethral plate(UP),essentially tubularized incised plate(TIP)repair in this report.There are several important aspects of hypospadias repair that need to be highlighted in this context.
基金supported by the US National Science Foundation(Grant No.1704933)The research of the second and the third authors are supported by the National Natural Science Foundation of China(Grant No.72231008)the Natural Science Basic Research Program of Shaanxi(Program No.2022JQ734).
文摘Reliability-redundancy allocation,preventive maintenance,and spare parts logistics are crucial for achieving system reliability and availability goal.Existing methods often concentrate on specific scopes of the system’s lifetime.This paper proposes a joint redundancymaintenance-inventory allocation model that simultaneously optimizes redundant component,replacement time,spares stocking,and repair capacity.Under reliability and availability criteria,our objective is to minimize the system’s lifetime cost,including design,manufacturing,and operational phases.We develop a unified system availability model based on ten performance drivers,serving as the foundation for the establishment of the lifetimebased resource allocation model.Superimposed renewal theory is employed to estimate spare part demand from proactive and corrective replacements.A bisection algorithm,enhanced by neighborhood exploration,solves the complex mixed-integer,nonlinear optimization problem.The numerical experiments show that component redundancy is preferred and necessary if one of the following situations occurs:extremely high system availability is required,the fleet size is small,the system reliability is immature,the inventory holding is too costly,or the handson replacement time is prolonged.The joint allocation model also reveals that there exists no monotonic relation between spares stocking level and system availability.
基金the National Natural Science Foundation of China(Grant No.82330090 and Grant No.82341006 to C.G.)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA0460403 to C.G.)the Natural Science Foundation of Shanxi Province(Grant No.202203021211155 to X.M.).
文摘Overview of the DNA damage response(DDR)in tumor cells.DDR is a highly coordinated signaling network that repairs DNA damage caused by intrinsic cellular processes and extrinsic insults,thereby preventing genome instability.Depending on the type of damage,distinct DNA damage repair and DNA damage tolerance(DDT)pathways are involved and coordinately regulated.
基金supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases(NIAMS)of the National Institutes of Health(NIH)under award numbers F30AR071201(R.L.Z.)and R01 AR066028(K.D.H.)Additional research support is provided by the NIH under a training award T32TR004371(C.A.C.).
文摘CD47 is a ubiquitous and pleiotropic cell-surface receptor.Disrupting CD47 enhances injury repair in various tissues but the role of CD47 has not been studied in bone injuries.In a murine closed-fracture model,CD47-null mice showed decreased callus bone formation as assessed by microcomputed tomography 10 days post-fracture and increased fibrous volume as determined by histology.To understand the cellular basis for this phenotype,mesenchymal progenitors(MSC)were harvested from bone marrow.CD47-null MSC showed decreased large fibroblast colony formation(CFU-F),significantly less proliferation,and fewer cells in Sphase,although osteoblast differentiation was unaffected.However,consistent with prior research,CD47-null endothelial cells showed increased proliferation relative to WT cells.Similarly,in a murine ischemic fracture model,CD47-null mice showed reduced fracture callus size due to a reduction in bone relative to WT 15 days-post fracture.Consistent with our in vitro results,in vivo EdU labeling showed decreased cell proliferation in the callus of CD47-null mice,while staining for CD31 and endomucin demonstrated increased endothelial cell density.Finally,WT mice with ischemic fracture that were administered a CD47 morpholino,which blocks CD47 protein production,showed a callus phenotype similar to that of ischemic fractures in CD47-null mice,suggesting the phenotype was not due to developmental changes in the knockout mice.Thus,inhibition of CD47 during bone healing reduces both non-ischemic and ischemic fracture healing,in part,by decreasing MSC proliferation.Furthermore,the increase in endothelial cell proliferation and early blood vessel density caused by CD47 disruption is not sufficient to overcome MSC dysfunction.
基金supported by the National Natural Science Foundation of China(82171386,81971161,and 82201536)the Shanghai Science and Technology Development Foundation(22YF1458600)+1 种基金the Scientifc Foundation from Naval Medical University(2021QN08)the STI2030-Major Projects from Ministry of Science and Technology of China(2022ZD0204700).
文摘In the mammalian central nervous system(CNS),astrocytes are the ubiquitous glial cells that have complex morphological and molecular characteristics.These fascinating cells play essential neurosupportive and homeostatic roles in the healthy CNS and undergo morphological,molecular,and functional changes to adopt so-called‘reactive’states in response to CNS injury or disease.In recent years,interest in astrocyte research has increased dramatically and some new biological features and roles of astrocytes in physiological and pathological conditions have been discovered thanks to technological advances.Here,we will review and discuss the wellestablished and emerging astroglial biology and functions,with emphasis on their potential as therapeutic targets for CNS injury,including traumatic and ischemic injury.This review article will highlight the importance of astrocytes in the neuropathological process and repair of CNS injury.
文摘BACKGROUND Skin wounds are common injuries that affect quality of life and incur high costs.A considerable portion of healthcare resources in Western countries is allocated to wound treatment,mainly using mechanical,biological,or artificial dressings.Biological and artificial dressings,such as hydrogels,are preferred for their biocompatibility.Platelet concentrates,such as platelet-rich plasma(PRP)and platelet-rich fibrin(PRF),stand out for accelerating tissue repair and minimizing risks of allergies and rejection.This study developed PRF and PRP-based dressings to treat skin wounds in an animal model,evaluating their functionality and efficiency in accelerating the tissue repair process.AIM To develop wound dressings based on platelet concentrates and evaluating their efficiency in treating skin wounds in Wistar rats.METHODS Wistar rats,both male and female,were subjected to the creation of a skin wound,distributed into groups(n=64/group),and treated with Carbopol(negative control);PRP+Carbopol;PRF+Carbopol;or PRF+CaCl_(2)+Carbopol,on days zero(D0),D3,D7,D14,and D21.PRP and PRF were obtained only from male rats.On D3,D7,D14,and D21,the wounds were analyzed for area,contraction rate,and histopathology of the tissue repair process.RESULTS The PRF-based dressing was more effective in accelerating wound closure early in the tissue repair process(up to D7),while PRF+CaCl_(2) seemed to delay the process,as wound closure was not complete by D21.Regarding macroscopic parameters,animals treated with PRF+CaCl_(2) showed significantly more crusting(necrosis)early in the repair process(D3).In terms of histopathological parameters,the PRF group exhibited significant collagenization at the later stages of the repair process(D14 and D21).By D21,fibroblast proliferation and inflammatory infiltration were higher in the PRP group.Animals treated with PRF+CaCl_(2) experienced a more pronounced inflammatory response up to D7,which diminished from D14 onwards.CONCLUSION The PRF-based dressing was effective in accelerating the closure of cutaneous wounds in Wistar rats early in the process and in aiding tissue repair at the later stages.
基金supported by grants from the Medical Engineering Jiont Fund of the Fudan University(No.IDH2310117)。
文摘Objective:Triple-negative breast cancer(TNBC)is a highly aggressive subtype that lacks targeted therapies,leading to a poorer prognosis.However,some patients achieve long-term recurrence-free survival(RFS),offering valuable insights into tumor biology and potential treatment strategies.Methods:We conducted a comprehensive multi-omics analysis of 132 patients with American Joint Committee on Cancer(AJCC)stage III TNBC,comprising 36 long-term survivors(RFS≥8 years),62 moderate-term survivors(RFS:3-8 years),and 34 short-term survivors(RFS<3 years).Analyses investigated clinicopathological factors,whole-exome sequencing,germline mutations,copy number alterations(CNAs),RNA sequences,and metabolomic profiles.Results:Long-term survivors exhibited fewer metastatic regional lymph nodes,along with tumors showing reduced stromal fibrosis and lower Ki67 index.Molecularly,these tumors exhibited multiple alterations in genes related to homologous recombination repair,with higher frequencies of germline mutations and somatic CNAs.Additionally,tumors from long-term survivors demonstrated significant downregulation of the RTK-RAS signaling pathway.Metabolomic profiling revealed decreased levels of lipids and carbohydrate,particularly those involved in glycerophospholipid,fructose,and mannose metabolism,in long-term survival group.Multivariate Cox analysis identified fibrosis[hazard ratio(HR):12.70,95%confidence interval(95%CI):2.19-73.54,P=0.005]and RAC1copy number loss/deletion(HR:0.22,95%CI:0.06-0.83,P=0.026)as independent predictors of RFS.Higher fructose/mannose metabolism was associated with worse overall survival(HR:1.30,95%CI:1.01-1.68,P=0.045).Our findings emphasize the association between biological determinants and prolonged survival in patients with TNBC.Conclusions:Our study systematically identified the key molecular and metabolic features associated with prolonged survival in AJCC stage III TNBC,suggesting potential therapeutic targets to improve patient outcomes.
基金supported in part by the National Natural Science Foundation of China(Nos.52205532 and 624B2077)the National Key Research and Development Program of China(No.2023YFB4302003).
文摘The global demand for effective skin injury treatments has prompted the exploration of tissue engineering solutions.While three-dimensional(3D)bioprinting has shown promise,challenges persist with respect to achieving timely and compatible solutions to treat diverse skin injuries.In situ bioprinting has emerged as a key new technology,since it reduces risks during the implantation of printed scaffolds and demonstrates superior therapeutic effects.However,maintaining printing fidelity during in situ bioprinting remains a critical challenge,particularly with respect to model layering and path planning.This study proposes a novel optimization-based conformal path planning strategy for in situ bioprinting-based repair of complex skin injuries.This strategy employs constrained optimization to identify optimal waypoints on a point cloud-approximated curved surface,thereby ensuring a high degree of similarity between predesigned planar and surface-mapped 3D paths.Furthermore,this method is applicable for skin wound treatments,since it generates 3D-equidistant zigzag curves along surface tangents and enables multi-layer conformal path planning to facilitate the treatment of volumetric injuries.Furthermore,the proposed algorithm was found to be a feasible and effective treatment in a murine back injury model as well as in other complex models,thereby showcasing its potential to guide in situ bioprinting,enhance bioprinting fidelity,and facilitate improvement of clinical outcomes.
基金supported by the Natio`nal Natural Science Foundation of China,No. 81801241a grant from Sichuan Science and Technology Program,No. 2023NSFSC1578Scientific Research Projects of Southwest Medical University,No. 2022ZD002 (all to JX)。
文摘Neuronal growth, extension, branching, and formation of neural networks are markedly influenced by the extracellular matrix—a complex network composed of proteins and carbohydrates secreted by cells. In addition to providing physical support for cells, the extracellular matrix also conveys critical mechanical stiffness cues. During the development of the nervous system, extracellular matrix stiffness plays a central role in guiding neuronal growth, particularly in the context of axonal extension, which is crucial for the formation of neural networks. In neural tissue engineering, manipulation of biomaterial stiffness is a promising strategy to provide a permissive environment for the repair and regeneration of injured nervous tissue. Recent research has fine-tuned synthetic biomaterials to fabricate scaffolds that closely replicate the stiffness profiles observed in the nervous system. In this review, we highlight the molecular mechanisms by which extracellular matrix stiffness regulates axonal growth and regeneration. We highlight the progress made in the development of stiffness-tunable biomaterials to emulate in vivo extracellular matrix environments, with an emphasis on their application in neural repair and regeneration, along with a discussion of the current limitations and future prospects. The exploration and optimization of the stiffness-tunable biomaterials has the potential to markedly advance the development of neural tissue engineering.
