Bone is a highly vascularized tissue, although this aspect of bone is often overlooked. In this article, the importance of blood flow in bone repair and regeneration will be reviewed. First, the skeletal vascular anat...Bone is a highly vascularized tissue, although this aspect of bone is often overlooked. In this article, the importance of blood flow in bone repair and regeneration will be reviewed. First, the skeletal vascular anato- my, with an emphasis on long bones, the distinct mechanisms for vascularizing bone tissue, and methods for remodeling existing vasculature are discussed. Next, techniques for quantifying bone blood flow are briefly summarized. Finally, the body of experimental work that demonstrates the role of bone blood flow in fracture healing, distraction osteogenesis, osteoporosis, disuse osteopenia, and bone grafting is examined. These results illustrate that adequate bone blood flow is an important clinical consideration, particularly during bone regeneration and in at-risk patient groups.展开更多
国际韧带和肌腱研讨会(The International Symposium on Ligaments and Tendons,ISI&T)于2000年在美国佛罗里达州奥兰多市首次召开。研讨会的宗旨是引起对韧带和肌腱研究的重视,并为生物工程师、生物学家、临床医师提供一个可以分...国际韧带和肌腱研讨会(The International Symposium on Ligaments and Tendons,ISI&T)于2000年在美国佛罗里达州奥兰多市首次召开。研讨会的宗旨是引起对韧带和肌腱研究的重视,并为生物工程师、生物学家、临床医师提供一个可以分享、评论、讨论韧带和肌腱最新研究成果的论坛。从2000年起,国际韧带和肌腱研讨会已经开展了15届;每届研讨会上涌现了大量令人振奋的关于当前韧带和肌腱研究热点和未来挑战的讨论。多年来,韧带和肌腱领域内的研究数量大幅增加,研究质量不断提升。为纪念《医用生物力学》杂志创刊30周年,本文总结过去30年里韧带和肌腱研究的主要进展,包括组织力学、力学生物学、损伤与治愈机制、组织修复和再生。展开更多
Three-dimensional(3D)bioprinting has revolutionized tissue engineering by enabling precise fabrication with bioinks.Among these techniques,digital light processing(DLP)stands out due to its exceptional resolution,spee...Three-dimensional(3D)bioprinting has revolutionized tissue engineering by enabling precise fabrication with bioinks.Among these techniques,digital light processing(DLP)stands out due to its exceptional resolution,speed,and biocompatibility.However,the progress of DLP is hindered by the limited availability of suitable bioinks.Currently,some studies involve simple mixing of different materials,resulting in bioinks that lack uniformity and photopolymerization characteristics.To address this challenge,we present an innovative one-pot synthesis method for bioinks based on methacrylated gelatin/alginate with hydroxyapatite(HAP).This approach offers significant advantages in terms of efficiency and uniformity.The synthesized bioinks demonstrate excellent printability,stability,and notably enhanced mechanical properties,facilitating optimal in vitro compatibility.Additionally,the HAP-hybrid bioinks printed scaffolds demonstrated impressive bone repair capabilities in vivo compared with pure organic bioinks.In conclusion,the Gel/Alg/HAP bioinks presented herein offer an innovative solution for DLP bioprinting within the field of bone tissue engineering.Their multifaceted advantages help overcome the limitations of restricted bioink choices,pushing forward the boundaries of bioprinting technology and contributing to the progress of regenerative medicine and tissue engineering.展开更多
Spinal cord injury（SCI）-induced bone loss represents the most severe osteoporosis with no effective treatment.Past animal studies have focused primarily on long bones at the acute stage using adolescent rodents. To ...Spinal cord injury（SCI）-induced bone loss represents the most severe osteoporosis with no effective treatment.Past animal studies have focused primarily on long bones at the acute stage using adolescent rodents. To mimic chronic SCI in human patients, we performed a comprehensive analysis of long-term structural and mechanical changes in axial and appendicular bones in adult rats after SCI. In this experiment, 4-month-old Fischer 344 male rats received a clinically relevant T13 contusion injury. Sixteen weeks later, sublesional femurs, tibiae,and L4 vertebrae, supralesional humeri, and blood were collected from these rats and additional non-surgery rats for micro-computed tomography（m CT）, micro-finite element, histology, and serum biochemical analyses.At trabecular sites, extreme losses of bone structure and mechanical competence were detected in the metaphysis of sublesional long bones after SCI, while the subchondral part of the same bones showed much milder damage. Marked reductions in bone mass and strength were also observed in sublesional L4 vertebrae but not in supralesional humeri. At cortical sites, SCI induced structural and strength damage in both sub- and supralesional long bones. These changes were accompanied by diminished osteoblast number and activity and increased osteoclast number and activity. Taken together, our study revealed site-specific effects of SCI on bone and demonstrated sustained inhibition of bone formation and elevation of bone resorption at the chronic stage of SCI.展开更多
Kinematics has been successfully used to describe body motion without reference to the kinetics (or forces causing the motion). In this article, both the theory and applications of the matrix method are provided to de...Kinematics has been successfully used to describe body motion without reference to the kinetics (or forces causing the motion). In this article, both the theory and applications of the matrix method are provided to describe complex human motion. After the definition of a Cartesian coordinate frame is introduced, the description of transformations between multiple coordinate frames is given; the decomposition of a transformation matrix into anatomical joint motion parameters (e.g. Euler angles) is then explained. The advantages of the matrix method are illustrated by three examples related to biomechanical studies. The first describes a reaching and grasping task in which matrix transformations are applied to position the hand with respect to an object during grasping. The second example demonstrates the utility of the matrix method in revealing the coupling motion of the wrist between flexion-extension and radial-ulnar deviation. The last example highlights the indispensable use of the matrix method for the study of knee biomechanics, including the description of knee joint kinematics during functional activities and determination of in-situ ligament forces using robotic technology, which has advanced our understanding of the functions of the cruciate ligaments to knee joint kinematics. It is hoped that the theoretical development and biomechanical application examples will help the readers apply the matrix method to research problems related to human motion.展开更多
Meniscus injuries present significant therapeutic challenges due to their limited self-healing capacity and the diverse biological and mechanical properties across the tissue.Conventional repair strategies do not repl...Meniscus injuries present significant therapeutic challenges due to their limited self-healing capacity and the diverse biological and mechanical properties across the tissue.Conventional repair strategies do not replicate the complex zonal characteristics within the meniscus,resulting in suboptimal outcomes.In this study,we introduce an innovative fetal/adult and stiffness-tunable meniscus decellularized extracellular matrix(DEM)-based hydrogel system designed for precision repair of heterogeneous,zonal-dependent meniscus injuries.By syn-thesizing fetal and adult DEM hydrogels,we identified distinct cellular responses,including that hydrogels with adult meniscus-derived DEM promote more fibrochondrogenic phenotypes.The incorporation of methacrylated hyaluronic acid(MeHA)further refined the mechanical properties and injectability of the DEM-based hydrogels.The combination of fetal and adult DEM with MeHA allowed for precise tuning of stiffness,influencing cell differentiation and closely mimicking native tissue environments.In vivo tests confirmed the biocompatibility of hydrogels and their integration with native meniscus tissues.Furthermore,advanced 3D bioprinting techniques enabled the fabrication of hybrid hydrogels with biomaterial and mechanical gradients,effectively emulating the zonal properties of meniscus tissue and enhancing cell integration.This study represents a significant advance in meniscus tissue engineering,providing a promising platform for customized regenerative therapies across a range of heterogeneous fibrous connective tissues.展开更多
The skeletal system is responsible for weight-bearing,organ protection,and movement.Bone diseases caused by trauma,infection,and aging can seriously affect a patient’s quality of life.Bone targeted biomaterials are s...The skeletal system is responsible for weight-bearing,organ protection,and movement.Bone diseases caused by trauma,infection,and aging can seriously affect a patient’s quality of life.Bone targeted biomaterials are suitable for the treatment of bone diseases.Biomaterials with bone-targeted properties can improve drug utilization and reduce side effects.A large number of bone-targeted micro-nano materials have been developed.However,only a few studies addressed bone-targeted hydrogel.The large size of hydrogel makes it difficult to achieve systematic targeting.However,local targeted hydrogel still has significant prospects.Molecules in bone/cartilage extracellular matrix and bone cells provide binding sites for bone-targeted hydrogel.Drug delivery systems featuring microgels with targeting properties is a key construction strategy for bone-targeted hydrogel.Besides,injectable hydrogel drug depot carrying bone-targeted drugs is another strategy.In this review,we summarize the bone-targeted hydrogel through application environment,construction strategies and disease applications.We hope this article will provide a reference for the development of bone-targeted hydrogels.We also hope this article could increase awareness of bone-targeted materials.展开更多
The necessity of disease models for bone/cartilage related disorders is well-recognized,but the barrier between ex-vivo cell culture,animal models and the real human body has been pending for decades.The organoid-on-a...The necessity of disease models for bone/cartilage related disorders is well-recognized,but the barrier between ex-vivo cell culture,animal models and the real human body has been pending for decades.The organoid-on-a-chip technique showed opportunity to revolutionize basic research and drug screening for diseases like osteoporosis and arthritis.The bone/cartilage organoid on-chip(BCoC)system is a novel platform of multi-tissue which faithfully emulate the essential elements,biologic functions and pathophysiological response under real circumstances.In this review,we propose the concept of BCoC platform,summarize the basic modules and current efforts to orchestrate them on a single microfluidic system.Current disease models,unsolved problems and future challenging are also discussed,the aim should be a deeper understanding of diseases,and ultimate realization of generic ex-vivo tools for further therapeutic strategies of pathological conditions.展开更多
In the past 20 years,patients with rheumatoid arthritis(RA),Crohn’s disease(CD),and other immune diseases have witnessed the impact of a great treatment advance with the availability of biological TNFa inhibitors.Wit...In the past 20 years,patients with rheumatoid arthritis(RA),Crohn’s disease(CD),and other immune diseases have witnessed the impact of a great treatment advance with the availability of biological TNFa inhibitors.With 5 approved anti-TNFa biologics on the market and soon available biosimilars,patients have more treatment options and have benefited from understanding the biology of TNFa.Nevertheless,many unmet needs remain for people living with TNFa-related diseases,namely some side effects and tolerance of current anti-TNFa biologics and resistance to therapies.Furthermore,common diseases such as osteoarthritis and back/neck pain may respond to anti-TNFa therapies at early onset of symptoms.Development of new TNFa inhibitors focusing on TNFR1 specific inhibitors,preferably small molecules that can be delivered orally,is much needed.展开更多
Background:Gait problems are an important symptom in Parkinson’s disease(PD),a progressive neurodegenerative disease.Transcranial direct current stimulation(tDCS)is a neuromodulatory intervention that can modulate co...Background:Gait problems are an important symptom in Parkinson’s disease(PD),a progressive neurodegenerative disease.Transcranial direct current stimulation(tDCS)is a neuromodulatory intervention that can modulate cortical excitability of the gait-related regions.Despite an increasing number of gait-related tDCS studies in PD,the efficacy of this technique for improving gait has not been systematically investigated yet.Here,we aimed to systematically explore the effects of tDCS on gait in PD,based on available experimental studies.Methods:Using the PRISMA(Preferred Reporting Items for Systematic Reviews and Meta-Analyses)approach,PubMed,Web of Science,Scopus,and PEDro databases were searched for randomized clinical trials assessing the effect of tDCS on gait in patients with PD.Results:Eighteen studies were included in this systematic review.Overall,tDCS targeting the motor cortex and supplementary motor area bilaterally seems to be promising for gait rehabilitation in PD.Studies of tDCS targeting the dorosolateral prefrontal cortex or cerebellum showed more heterogeneous results.More studies are needed to systematically compare the efficacy of different tDCS protocols,including protocols applying tDCS alone and/or in combination with conventional gait rehabilitation treatment in PD.Conclusions:tDCS is a promising intervention approach to improving gait in PD.Anodal tDCS over the motor areas has shown a positive effect on gait,but stimulation of other areas is less promising.However,the heterogeneities of methods and results have made it difficult to draw firm conclusions.Therefore,systematic explorations of tDCS protocols are required to optimize the efficacy.展开更多
The single best predictor of future fracture risk is a prior fracture at any skeletal site.However,the mechanisms underlying this relationship remain incompletely understood.Here we review three potential mechanisms u...The single best predictor of future fracture risk is a prior fracture at any skeletal site.However,the mechanisms underlying this relationship remain incompletely understood.Here we review three potential mechanisms underlying increased risk.An index fracture may reflect preexisting deficits in bone quality or impairments in physical function.Second,fracture may cause biomechanical changes that increase future fracture risk.Third,fracture induces a period of systemic bone loss that is never fully recovered.Further investigation into these mechanisms can inform treatments that prevent future fractures for individuals with a prior history of fracture.展开更多
Simulating human brain development accurately has the potential to improve our understanding of human brain development and various brain disorders.Although animal models play an indispensable role in the field of dev...Simulating human brain development accurately has the potential to improve our understanding of human brain development and various brain disorders.Although animal models play an indispensable role in the field of developmental neurobiology,inherent species differences limit their capacity to replicate the intricacies of specific human diseases.1 In light of these limitations,recent advancements in the technology of brain organoids present a promising avenue for investigating the development and functionality of the human brain.Regional brain organoids,such as those derived from dorsal and ventral forebrain,maintain their regional identity and recapitulate many aspects of early development,while whole brain organoids develop various discrete brain regions but may not fully replicate the regional specificity seen in vivo.展开更多
基金Supported by grants from the National Institutes of Health(R01 AR050211P30 AR057235)
文摘Bone is a highly vascularized tissue, although this aspect of bone is often overlooked. In this article, the importance of blood flow in bone repair and regeneration will be reviewed. First, the skeletal vascular anato- my, with an emphasis on long bones, the distinct mechanisms for vascularizing bone tissue, and methods for remodeling existing vasculature are discussed. Next, techniques for quantifying bone blood flow are briefly summarized. Finally, the body of experimental work that demonstrates the role of bone blood flow in fracture healing, distraction osteogenesis, osteoporosis, disuse osteopenia, and bone grafting is examined. These results illustrate that adequate bone blood flow is an important clinical consideration, particularly during bone regeneration and in at-risk patient groups.
文摘国际韧带和肌腱研讨会(The International Symposium on Ligaments and Tendons,ISI&T)于2000年在美国佛罗里达州奥兰多市首次召开。研讨会的宗旨是引起对韧带和肌腱研究的重视,并为生物工程师、生物学家、临床医师提供一个可以分享、评论、讨论韧带和肌腱最新研究成果的论坛。从2000年起,国际韧带和肌腱研讨会已经开展了15届;每届研讨会上涌现了大量令人振奋的关于当前韧带和肌腱研究热点和未来挑战的讨论。多年来,韧带和肌腱领域内的研究数量大幅增加,研究质量不断提升。为纪念《医用生物力学》杂志创刊30周年,本文总结过去30年里韧带和肌腱研究的主要进展,包括组织力学、力学生物学、损伤与治愈机制、组织修复和再生。
基金financial support from the National Natural Science Foundation of China(Nos.82202335,82230071,and 82172098)the Shanghai Sailing Program(No.22YF1414000).
文摘Three-dimensional(3D)bioprinting has revolutionized tissue engineering by enabling precise fabrication with bioinks.Among these techniques,digital light processing(DLP)stands out due to its exceptional resolution,speed,and biocompatibility.However,the progress of DLP is hindered by the limited availability of suitable bioinks.Currently,some studies involve simple mixing of different materials,resulting in bioinks that lack uniformity and photopolymerization characteristics.To address this challenge,we present an innovative one-pot synthesis method for bioinks based on methacrylated gelatin/alginate with hydroxyapatite(HAP).This approach offers significant advantages in terms of efficiency and uniformity.The synthesized bioinks demonstrate excellent printability,stability,and notably enhanced mechanical properties,facilitating optimal in vitro compatibility.Additionally,the HAP-hybrid bioinks printed scaffolds demonstrated impressive bone repair capabilities in vivo compared with pure organic bioinks.In conclusion,the Gel/Alg/HAP bioinks presented herein offer an innovative solution for DLP bioprinting within the field of bone tissue engineering.Their multifaceted advantages help overcome the limitations of restricted bioink choices,pushing forward the boundaries of bioprinting technology and contributing to the progress of regenerative medicine and tissue engineering.
基金supported by the National Institutes of Health(R01DK095803 to LQ, 1K08HD049598 to YZ)Penn Center for Musculoskeletal Disorders P30AR050950(NIAMS/NIH)+1 种基金ASBMR Junior Faculty Osteoporosis Basic Research Award(to LQ)NIH/NIAMS R03-AR065145(to XSL)
文摘Spinal cord injury（SCI）-induced bone loss represents the most severe osteoporosis with no effective treatment.Past animal studies have focused primarily on long bones at the acute stage using adolescent rodents. To mimic chronic SCI in human patients, we performed a comprehensive analysis of long-term structural and mechanical changes in axial and appendicular bones in adult rats after SCI. In this experiment, 4-month-old Fischer 344 male rats received a clinically relevant T13 contusion injury. Sixteen weeks later, sublesional femurs, tibiae,and L4 vertebrae, supralesional humeri, and blood were collected from these rats and additional non-surgery rats for micro-computed tomography（m CT）, micro-finite element, histology, and serum biochemical analyses.At trabecular sites, extreme losses of bone structure and mechanical competence were detected in the metaphysis of sublesional long bones after SCI, while the subchondral part of the same bones showed much milder damage. Marked reductions in bone mass and strength were also observed in sublesional L4 vertebrae but not in supralesional humeri. At cortical sites, SCI induced structural and strength damage in both sub- and supralesional long bones. These changes were accompanied by diminished osteoblast number and activity and increased osteoclast number and activity. Taken together, our study revealed site-specific effects of SCI on bone and demonstrated sustained inhibition of bone formation and elevation of bone resorption at the chronic stage of SCI.
文摘Kinematics has been successfully used to describe body motion without reference to the kinetics (or forces causing the motion). In this article, both the theory and applications of the matrix method are provided to describe complex human motion. After the definition of a Cartesian coordinate frame is introduced, the description of transformations between multiple coordinate frames is given; the decomposition of a transformation matrix into anatomical joint motion parameters (e.g. Euler angles) is then explained. The advantages of the matrix method are illustrated by three examples related to biomechanical studies. The first describes a reaching and grasping task in which matrix transformations are applied to position the hand with respect to an object during grasping. The second example demonstrates the utility of the matrix method in revealing the coupling motion of the wrist between flexion-extension and radial-ulnar deviation. The last example highlights the indispensable use of the matrix method for the study of knee biomechanics, including the description of knee joint kinematics during functional activities and determination of in-situ ligament forces using robotic technology, which has advanced our understanding of the functions of the cruciate ligaments to knee joint kinematics. It is hoped that the theoretical development and biomechanical application examples will help the readers apply the matrix method to research problems related to human motion.
基金supported by the National Institutes of Health(K01 AR07787,R21 R077700,P30 AR069619,R01 AR056624,R01 HL163168)National Science Foundation(CMMI 1548571)+2 种基金Department of Veterans Affairs(CReATE Motion Center,I50 RX004845)in the United Statessupported by the Korea Health Technology R&D Project through the Korea Health Industry Develop-ment Institute(KHIDI)funded by the Ministry of Health and Welfare(HI19C1095)National R&D Program through the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(RS-2024-00405574)in the Republic of Korea.
文摘Meniscus injuries present significant therapeutic challenges due to their limited self-healing capacity and the diverse biological and mechanical properties across the tissue.Conventional repair strategies do not replicate the complex zonal characteristics within the meniscus,resulting in suboptimal outcomes.In this study,we introduce an innovative fetal/adult and stiffness-tunable meniscus decellularized extracellular matrix(DEM)-based hydrogel system designed for precision repair of heterogeneous,zonal-dependent meniscus injuries.By syn-thesizing fetal and adult DEM hydrogels,we identified distinct cellular responses,including that hydrogels with adult meniscus-derived DEM promote more fibrochondrogenic phenotypes.The incorporation of methacrylated hyaluronic acid(MeHA)further refined the mechanical properties and injectability of the DEM-based hydrogels.The combination of fetal and adult DEM with MeHA allowed for precise tuning of stiffness,influencing cell differentiation and closely mimicking native tissue environments.In vivo tests confirmed the biocompatibility of hydrogels and their integration with native meniscus tissues.Furthermore,advanced 3D bioprinting techniques enabled the fabrication of hybrid hydrogels with biomaterial and mechanical gradients,effectively emulating the zonal properties of meniscus tissue and enhancing cell integration.This study represents a significant advance in meniscus tissue engineering,providing a promising platform for customized regenerative therapies across a range of heterogeneous fibrous connective tissues.
基金This work was funded by the National Key R&D Program of China(2018YFC2001500)Key Project of The National Natural Science Foundation of China(82230071)National Natural Science Foundation of China(82172098,32101084).
文摘The skeletal system is responsible for weight-bearing,organ protection,and movement.Bone diseases caused by trauma,infection,and aging can seriously affect a patient’s quality of life.Bone targeted biomaterials are suitable for the treatment of bone diseases.Biomaterials with bone-targeted properties can improve drug utilization and reduce side effects.A large number of bone-targeted micro-nano materials have been developed.However,only a few studies addressed bone-targeted hydrogel.The large size of hydrogel makes it difficult to achieve systematic targeting.However,local targeted hydrogel still has significant prospects.Molecules in bone/cartilage extracellular matrix and bone cells provide binding sites for bone-targeted hydrogel.Drug delivery systems featuring microgels with targeting properties is a key construction strategy for bone-targeted hydrogel.Besides,injectable hydrogel drug depot carrying bone-targeted drugs is another strategy.In this review,we summarize the bone-targeted hydrogel through application environment,construction strategies and disease applications.We hope this article will provide a reference for the development of bone-targeted hydrogels.We also hope this article could increase awareness of bone-targeted materials.
基金This work was supported by grants from National Natural Science Foundation of China(No.82230071,92249303 and 82172098 to J.Su)Shanghai Committee of Science and Technology(Laboratory Animal Research Project to J.Su)+1 种基金Shanghai Baoshan District Medical Health Project(No.21-E-14 to L.Cao)China Postdoctoral Science Foundation(No.2022M722033 to Y.Hu).
文摘The necessity of disease models for bone/cartilage related disorders is well-recognized,but the barrier between ex-vivo cell culture,animal models and the real human body has been pending for decades.The organoid-on-a-chip technique showed opportunity to revolutionize basic research and drug screening for diseases like osteoporosis and arthritis.The bone/cartilage organoid on-chip(BCoC)system is a novel platform of multi-tissue which faithfully emulate the essential elements,biologic functions and pathophysiological response under real circumstances.In this review,we propose the concept of BCoC platform,summarize the basic modules and current efforts to orchestrate them on a single microfluidic system.Current disease models,unsolved problems and future challenging are also discussed,the aim should be a deeper understanding of diseases,and ultimate realization of generic ex-vivo tools for further therapeutic strategies of pathological conditions.
基金the Department of Veterans Affairs Healthcare Network,a Penn Center for Musculoskeletal Disorders(PCMD)pilot grant(P30-AR050950-10 Pilot)a grant from the National Institute of Arthritis and Musculoskeletal and Skin Diseases(NIAMS,R21 AR071623).
文摘In the past 20 years,patients with rheumatoid arthritis(RA),Crohn’s disease(CD),and other immune diseases have witnessed the impact of a great treatment advance with the availability of biological TNFa inhibitors.With 5 approved anti-TNFa biologics on the market and soon available biosimilars,patients have more treatment options and have benefited from understanding the biology of TNFa.Nevertheless,many unmet needs remain for people living with TNFa-related diseases,namely some side effects and tolerance of current anti-TNFa biologics and resistance to therapies.Furthermore,common diseases such as osteoarthritis and back/neck pain may respond to anti-TNFa therapies at early onset of symptoms.Development of new TNFa inhibitors focusing on TNFR1 specific inhibitors,preferably small molecules that can be delivered orally,is much needed.
基金This work was supported by the Musculoskeletal Research Center,Isfahan University of Medical Sciences,Isfahan,Iran.
文摘Background:Gait problems are an important symptom in Parkinson’s disease(PD),a progressive neurodegenerative disease.Transcranial direct current stimulation(tDCS)is a neuromodulatory intervention that can modulate cortical excitability of the gait-related regions.Despite an increasing number of gait-related tDCS studies in PD,the efficacy of this technique for improving gait has not been systematically investigated yet.Here,we aimed to systematically explore the effects of tDCS on gait in PD,based on available experimental studies.Methods:Using the PRISMA(Preferred Reporting Items for Systematic Reviews and Meta-Analyses)approach,PubMed,Web of Science,Scopus,and PEDro databases were searched for randomized clinical trials assessing the effect of tDCS on gait in patients with PD.Results:Eighteen studies were included in this systematic review.Overall,tDCS targeting the motor cortex and supplementary motor area bilaterally seems to be promising for gait rehabilitation in PD.Studies of tDCS targeting the dorosolateral prefrontal cortex or cerebellum showed more heterogeneous results.More studies are needed to systematically compare the efficacy of different tDCS protocols,including protocols applying tDCS alone and/or in combination with conventional gait rehabilitation treatment in PD.Conclusions:tDCS is a promising intervention approach to improving gait in PD.Anodal tDCS over the motor areas has shown a positive effect on gait,but stimulation of other areas is less promising.However,the heterogeneities of methods and results have made it difficult to draw firm conclusions.Therefore,systematic explorations of tDCS protocols are required to optimize the efficacy.
基金The authors are supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases(NIAMS),under award number R01 AR071459.The project described was also supported by the National Center for Advancing Translational Sciences,National Institutes of Health,through grant number UL1 TR001860 and linked award TL1 TR001861.
文摘The single best predictor of future fracture risk is a prior fracture at any skeletal site.However,the mechanisms underlying this relationship remain incompletely understood.Here we review three potential mechanisms underlying increased risk.An index fracture may reflect preexisting deficits in bone quality or impairments in physical function.Second,fracture may cause biomechanical changes that increase future fracture risk.Third,fracture induces a period of systemic bone loss that is never fully recovered.Further investigation into these mechanisms can inform treatments that prevent future fractures for individuals with a prior history of fracture.
基金supported by the Foundation of National Center for Translational Medicine(Shanghai)SHU Branch(No.SUITM-202409).
文摘Simulating human brain development accurately has the potential to improve our understanding of human brain development and various brain disorders.Although animal models play an indispensable role in the field of developmental neurobiology,inherent species differences limit their capacity to replicate the intricacies of specific human diseases.1 In light of these limitations,recent advancements in the technology of brain organoids present a promising avenue for investigating the development and functionality of the human brain.Regional brain organoids,such as those derived from dorsal and ventral forebrain,maintain their regional identity and recapitulate many aspects of early development,while whole brain organoids develop various discrete brain regions but may not fully replicate the regional specificity seen in vivo.
