Taste buds relay taste sensory information to the primary taste neurons but depend on those same neurons for essential components to maintain function.While denervation-induced taste bud degeneration and subsequent re...Taste buds relay taste sensory information to the primary taste neurons but depend on those same neurons for essential components to maintain function.While denervation-induced taste bud degeneration and subsequent regeneration were discovered decades ago,the mechanisms underlying these phenomena(e.g.,heterogenous cellular responses to nerve injury and the signaling pathways involved)remain poorly understood.Here,using mouse genetics,nerve injury models,pharmacologic manipulation,and taste bud organoid models,we identify a specific subpopulation of taste cells,predominantly c-Kit-expressing sweet cells,that exhibit superior resistance to nerve injury.We found the c-Kit inhibitor imatinib selectively reduced the number of residual c-Kit-expressing sweet cells at post-operation week 2,subsequently attenuating the re-emergence of other type II cells by post-operation week 4.In taste bud organoids,c-Kit-expressing cells were resistant to R-spondin withdrawal but susceptible to imatinib,while other taste cell types showed the opposite behavior.We also observed a distinct population of residual taste cells that acquired stem-like properties,generating clonal descendent cells among suprabasal keratinocytes independent of c-Kit signaling.Together,our findings reveal that c-Kit signaling confers resilience on c-Kit-expressing sweet cells and supports the broader reconstruction of taste buds during the later regenerative stage following nerve injury.展开更多
Intentional tooth replantation(ITR)is an advanced treatment modality and the procedure of last resort for preserving teeth with inaccessible endodontic or resorptive lesions.ITR is defined as the deliberate extraction...Intentional tooth replantation(ITR)is an advanced treatment modality and the procedure of last resort for preserving teeth with inaccessible endodontic or resorptive lesions.ITR is defined as the deliberate extraction of a tooth;evaluation of the root surface,endodontic manipulation,and repair;and placement of the tooth back into its original socket.Case reports,case series,cohort studies,and randomized controlled trials have demonstrated the efficacy of ITR in the retention of natural teeth that are untreatable or difficult to manage with root canal treatment or endodontic microsurgery.However,variations in clinical protocols for ITR exist due to the empirical nature of the original protocols and rapid advancements in the field of oral biology and dental materials.This heterogeneity in protocols may cause confusion among dental practitioners;therefore,guidelines and considerations for ITR should be explicated.This expert consensus discusses the biological foundation of ITR,the available clinical protocols and current status of ITR in treating teeth with refractory apical periodontitis or anatomical aberration,and the main complications of this treatment,aiming to refine the clinical management of ITR in accordance with the progress of basic research and clinical studies;the findings suggest that ITR may become a more consistent evidence-based option in dental treatment.展开更多
This paper addresses a critical challenge in the design of MEMS actuators:the rejection of out-of-plane motion,specifically along the Z-axis,which can severely impact the precision and performance of these micro-actua...This paper addresses a critical challenge in the design of MEMS actuators:the rejection of out-of-plane motion,specifically along the Z-axis,which can severely impact the precision and performance of these micro-actuation systems.In many MEMS applications,unwanted out-of-plane displacement can lead to reduced accuracy in tasks such as optical steering,micro-manipulation,and scanning applications.In response to these limitations,this paper proposes a novel design technique that effectively rejects Z-axis motion by transforming the motion of the micro stage along the Z-axis into equivalent displacements between pairs of points on cantilevers.These point pairs are founded exhibiting variable common-mode and differential-mode motion characteristics,depending on whether the stage is undergoing in-plane(X/Y)or out-of-plane(Z)displacements.By connecting these point pairs with rods,differential motion between the points in the pairs is suppressed,reducing unwanted out-of-plane motion significantly.We provide a detailed analysis of this design methodology and present a practical application in the form of an electromagnetic large displacement MEMS actuator.This actuator undergoes a complete design-simulationmanufacturing-testing cycle,where the effectiveness of the Z-axis motion rejection structure is systematically evaluated,and compared against traditional designs.Experimental results reveal a significant improvement in performance,with static and dynamic travel ranges reaching±60μm and±400μm,respectively.Moreover,the Z-axis stiffness was enhanced by 68.5%,which is more than five times the improvement observed in the X/Y axes’stiffness.These results highlight the potential of the proposed method to provide a robust solution for out-of-plane motion suppression in MEMS actuators,offering improved performance without compromising other critical parameters such as displacement and actuation speed.展开更多
基金supported by a National Research Foundation of Korea(NRF)grant funded by the Korean Government(Ministry of Science and ICT,RS-2023-00208193 to Y.T.J.)by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute(KHIDI)funded by the Ministry of Health&Welfare(RS-2024-00403511 to D.-H.K.)by a Korea University grant(K2117151 to Y.T.J.)。
文摘Taste buds relay taste sensory information to the primary taste neurons but depend on those same neurons for essential components to maintain function.While denervation-induced taste bud degeneration and subsequent regeneration were discovered decades ago,the mechanisms underlying these phenomena(e.g.,heterogenous cellular responses to nerve injury and the signaling pathways involved)remain poorly understood.Here,using mouse genetics,nerve injury models,pharmacologic manipulation,and taste bud organoid models,we identify a specific subpopulation of taste cells,predominantly c-Kit-expressing sweet cells,that exhibit superior resistance to nerve injury.We found the c-Kit inhibitor imatinib selectively reduced the number of residual c-Kit-expressing sweet cells at post-operation week 2,subsequently attenuating the re-emergence of other type II cells by post-operation week 4.In taste bud organoids,c-Kit-expressing cells were resistant to R-spondin withdrawal but susceptible to imatinib,while other taste cell types showed the opposite behavior.We also observed a distinct population of residual taste cells that acquired stem-like properties,generating clonal descendent cells among suprabasal keratinocytes independent of c-Kit signaling.Together,our findings reveal that c-Kit signaling confers resilience on c-Kit-expressing sweet cells and supports the broader reconstruction of taste buds during the later regenerative stage following nerve injury.
文摘Intentional tooth replantation(ITR)is an advanced treatment modality and the procedure of last resort for preserving teeth with inaccessible endodontic or resorptive lesions.ITR is defined as the deliberate extraction of a tooth;evaluation of the root surface,endodontic manipulation,and repair;and placement of the tooth back into its original socket.Case reports,case series,cohort studies,and randomized controlled trials have demonstrated the efficacy of ITR in the retention of natural teeth that are untreatable or difficult to manage with root canal treatment or endodontic microsurgery.However,variations in clinical protocols for ITR exist due to the empirical nature of the original protocols and rapid advancements in the field of oral biology and dental materials.This heterogeneity in protocols may cause confusion among dental practitioners;therefore,guidelines and considerations for ITR should be explicated.This expert consensus discusses the biological foundation of ITR,the available clinical protocols and current status of ITR in treating teeth with refractory apical periodontitis or anatomical aberration,and the main complications of this treatment,aiming to refine the clinical management of ITR in accordance with the progress of basic research and clinical studies;the findings suggest that ITR may become a more consistent evidence-based option in dental treatment.
基金the National Natural Science Foundation of China(Grant No.U21A6003&Grant No.U24A6006).
文摘This paper addresses a critical challenge in the design of MEMS actuators:the rejection of out-of-plane motion,specifically along the Z-axis,which can severely impact the precision and performance of these micro-actuation systems.In many MEMS applications,unwanted out-of-plane displacement can lead to reduced accuracy in tasks such as optical steering,micro-manipulation,and scanning applications.In response to these limitations,this paper proposes a novel design technique that effectively rejects Z-axis motion by transforming the motion of the micro stage along the Z-axis into equivalent displacements between pairs of points on cantilevers.These point pairs are founded exhibiting variable common-mode and differential-mode motion characteristics,depending on whether the stage is undergoing in-plane(X/Y)or out-of-plane(Z)displacements.By connecting these point pairs with rods,differential motion between the points in the pairs is suppressed,reducing unwanted out-of-plane motion significantly.We provide a detailed analysis of this design methodology and present a practical application in the form of an electromagnetic large displacement MEMS actuator.This actuator undergoes a complete design-simulationmanufacturing-testing cycle,where the effectiveness of the Z-axis motion rejection structure is systematically evaluated,and compared against traditional designs.Experimental results reveal a significant improvement in performance,with static and dynamic travel ranges reaching±60μm and±400μm,respectively.Moreover,the Z-axis stiffness was enhanced by 68.5%,which is more than five times the improvement observed in the X/Y axes’stiffness.These results highlight the potential of the proposed method to provide a robust solution for out-of-plane motion suppression in MEMS actuators,offering improved performance without compromising other critical parameters such as displacement and actuation speed.
