Avulsion injury of one or more spinal ventral roots induces a critical loss of motoneurons,followed by irreversible locomotor function impairment ranging from inadequate limb movement to complete paralysis of the limb...Avulsion injury of one or more spinal ventral roots induces a critical loss of motoneurons,followed by irreversible locomotor function impairment ranging from inadequate limb movement to complete paralysis of the limb.Recent surgical techniques facilitate improvement of limb function,but it remains to be determined exactly how many motoneurons are needed to survive and grow new axons to achieve sufficient muscle reinnervation.The aim of this study was to determine the minimum motoneuron quantity required to reinnervate the denervated skeletal muscles of the limb and produce a functionally satisfactory locomotor pattern.Since none of the commercially available methods and equipment were able to provide a quantifiable and in-depth analysis of the motor pattern of the entire hind limb,we have developed and applied a sensitive movement recording and analyzing system in order to determine the threshold of satisfactory functional reinnervation;we combined video-based footprint analysis and hind limb motion analysis to achieve a new and reliable assessment.Sprague-Dawley rats underwent a lumbar 4-5 ventral root avulsion,and their L4 ventral roots were subsequently reimplanted.The animals received different doses of riluzole treatment in order to rescue incremental numbers of the damaged motoneuron pool.We were able to assess one rear-view and six lateral parameters of the hind limb movement pattern by measuring specific joint angles,footprint,and gait parameters in single video frames.Four months after the operation,we performed Fast Blue retrograde tracing to label and count the reinnervating motoneurons.We then compared the numbers of reinnervating motoneurons and the functional improvement.Our results confirmed a strong relationship between functional restoration of the original movement pattern and morphological reinnervation;approximately 30%of the original motor pool was able to produce a useful locomotor pattern.We believe that our knowledge of the minimal motoneuron numbers required to reinnervate target muscles may help plan the segmental redistribution of the motoneuron pools for reinnervation surgeries.展开更多
Backswimmers exhibit a high degree of mobility in water,and their different motion patterns have important implications for the design of micro-biomimetic underwater robots.This paper used three-dimensional high-speed...Backswimmers exhibit a high degree of mobility in water,and their different motion patterns have important implications for the design of micro-biomimetic underwater robots.This paper used three-dimensional high-speed cameras to extract the key points on the hind legs.The hind leg motion laws and the deformation laws of the setae were obtained in four motion patterns:rapid forward,cruising,in-motion turning,and in-place turning.The motion laws of each joint on the hind leg are modeled using a Fourier series.A kinematic model of hind legs was established based on the DH method,and the motion characteristics of hind legs under different motion patterns were analyzed.This paper provides basic data and theoretical models for micro-biomimetic robots.展开更多
Pork hind legs have low fat and high protein contents,making cured pork prone to a dry and tough texture.To address this issue,0.8%(w/w)natural polysaccharide curdlan was added to cured pork.Physicochemical indicators...Pork hind legs have low fat and high protein contents,making cured pork prone to a dry and tough texture.To address this issue,0.8%(w/w)natural polysaccharide curdlan was added to cured pork.Physicochemical indicators,free amino acids,and flavor were tested on days 0,10,20,and 30 of curing.The results indicated that curdlan increased product yield by 4.08%,slowed moisture loss during processing,and reduced pH from 6.02 to 5.21.It also decreased the hardness,chewiness,and stickiness in cured pork hind legs,yielding a softer texture.In addition,it slowed the rate of color deterioration and inhibited fat oxidation.Analysis of volatile flavor compounds revealed that curdlan increased the variety of flavor compounds in cured pork hind legs by more than twenty types.The odor activity values of key aroma components(such as linalool and nonanal)also increased to varying degrees,enriching the flavor profile of the cured meat.Thus,curdlan effectively improves the texture,color,and flavor of cured pork hind legs,providing process parameters for industrial production of low-fat cured meat.展开更多
In an attempt to realize a flapping wing micro-air vehicle with morphing wings, we report on improvements to our previousfoldable artificial hind wing.Multiple hinges, which were implemented to mimic the bending zone ...In an attempt to realize a flapping wing micro-air vehicle with morphing wings, we report on improvements to our previousfoldable artificial hind wing.Multiple hinges, which were implemented to mimic the bending zone of a beetle hind wing, weremade of small composite hinge plates and tiny aluminum rivets.The buck-tails of rivets were flared after the hinge plates wereassembled with the rivets so that the folding/unfolding motions could be completed in less time, and the straight shape of theartificial hind wing could be maintained after fabrication.Folding and unfolding actions were triggered by electrically-activatedShape Memory Alloy (SMA) wires.For wing folding, the actuation characteristics of the SMA wire actuator were modifiedthrough heat treatment.Through a series of flapping tests, we confirmed that the artificial wings did not fold back and arbitrarilyfluctuate during the flapping motion.展开更多
Dark Agouti rat donor hind limbs were orthotopically transplanted into Lewis rat recipients to verify the effects of bone marrow mesenchymal stem cells on neural regeneration and functional recovery of allotransplante...Dark Agouti rat donor hind limbs were orthotopically transplanted into Lewis rat recipients to verify the effects of bone marrow mesenchymal stem cells on neural regeneration and functional recovery of allotransplanted limbs in the microenvironment of immunotolerance, bone marrow mesenchymal stem cells were intramuscularly （gluteus maximus） injected with FK506 （tacrolimus） daily, and were transplanted to the injured nerves. Results indicated that the allograft group not receiving therapy showed severe rejection, with transplanted limbs detaching at 10 days after transplantation with complete necrosis. The number of myelinated axons and Schwann cells in the FK506 and FK506 ＋ bone marrow mesenchymal stem cells groups were significantly increased. We observed a lesser degree of gastrocnemius muscle degeneration, and increased polymorphic fibers along with other pathological changes in the FK506 ＋ bone marrow mesenchymal stem cells group. The FK506 ＋ bone marrow mesenchymal stem cells group showed significantly better recovery than the autograft and FK506 groups. The results demonstrated that FK506 improved the immune microenvironment. FK506 combined with bone marrow mesenchymal stem cells significantly promoted sciatic nerve regeneration, and improved sensory recovery and motor function in hind limb allotransplant.展开更多
The goat’s hind limbs play an important role in dampening vibrations caused by ground impact during movement.Inspired by the unique structure of their hind limbs,a novel bionic limb vibration isolator has been develo...The goat’s hind limbs play an important role in dampening vibrations caused by ground impact during movement.Inspired by the unique structure of their hind limbs,a novel bionic limb vibration isolator has been developed to suppress low-frequency vibrations.It consists of the base,the carrying platform,four bionic legs and so on.The bionic legs are made up of rods of varying lengths and springs in different directions to imitate the various shapes of bones such as the femur and patella of the hind limbs of goats and developed muscles such as the biceps and quadriceps.The bionic device was found to have excellent nonlinear stiffness through statics analysis,and could be flexibly adjusted to the work range and load capacity.The bionic vibration isolator offers lower natural frequencies(2.3 Hz),better vibration isolation effect and a wider vibration isolation band than conventional linear vibration isolator.The bionic device can effectively suppress vibrations above 3.2 Hz and reduce the amplitude of random vibrations to more than 90%.In addition,compared to similar bionic vibration isolation devices,the bionic isolator achieves excellent load-bearing capacity in a smaller size,which facilitates its application in practical production.展开更多
文摘Avulsion injury of one or more spinal ventral roots induces a critical loss of motoneurons,followed by irreversible locomotor function impairment ranging from inadequate limb movement to complete paralysis of the limb.Recent surgical techniques facilitate improvement of limb function,but it remains to be determined exactly how many motoneurons are needed to survive and grow new axons to achieve sufficient muscle reinnervation.The aim of this study was to determine the minimum motoneuron quantity required to reinnervate the denervated skeletal muscles of the limb and produce a functionally satisfactory locomotor pattern.Since none of the commercially available methods and equipment were able to provide a quantifiable and in-depth analysis of the motor pattern of the entire hind limb,we have developed and applied a sensitive movement recording and analyzing system in order to determine the threshold of satisfactory functional reinnervation;we combined video-based footprint analysis and hind limb motion analysis to achieve a new and reliable assessment.Sprague-Dawley rats underwent a lumbar 4-5 ventral root avulsion,and their L4 ventral roots were subsequently reimplanted.The animals received different doses of riluzole treatment in order to rescue incremental numbers of the damaged motoneuron pool.We were able to assess one rear-view and six lateral parameters of the hind limb movement pattern by measuring specific joint angles,footprint,and gait parameters in single video frames.Four months after the operation,we performed Fast Blue retrograde tracing to label and count the reinnervating motoneurons.We then compared the numbers of reinnervating motoneurons and the functional improvement.Our results confirmed a strong relationship between functional restoration of the original movement pattern and morphological reinnervation;approximately 30%of the original motor pool was able to produce a useful locomotor pattern.We believe that our knowledge of the minimal motoneuron numbers required to reinnervate target muscles may help plan the segmental redistribution of the motoneuron pools for reinnervation surgeries.
基金supported by the National Natural Science Foundation of China(52475307)the Shandong Provincial Natural Science Foundation(ZR2023ME041).
文摘Backswimmers exhibit a high degree of mobility in water,and their different motion patterns have important implications for the design of micro-biomimetic underwater robots.This paper used three-dimensional high-speed cameras to extract the key points on the hind legs.The hind leg motion laws and the deformation laws of the setae were obtained in four motion patterns:rapid forward,cruising,in-motion turning,and in-place turning.The motion laws of each joint on the hind leg are modeled using a Fourier series.A kinematic model of hind legs was established based on the DH method,and the motion characteristics of hind legs under different motion patterns were analyzed.This paper provides basic data and theoretical models for micro-biomimetic robots.
基金Supported by Sichuan Science and Technology Program(2024ZHCG0091)National Modern Agricultural Industry Technology System Sichuan Swine Innovation Team(SCCXTD-2025-8)+1 种基金Open Fund of Sichuan Provincial Key Laboratory of Meat Processing(24-R-20)China Agricultural Industry Research System(CARS-43).
文摘Pork hind legs have low fat and high protein contents,making cured pork prone to a dry and tough texture.To address this issue,0.8%(w/w)natural polysaccharide curdlan was added to cured pork.Physicochemical indicators,free amino acids,and flavor were tested on days 0,10,20,and 30 of curing.The results indicated that curdlan increased product yield by 4.08%,slowed moisture loss during processing,and reduced pH from 6.02 to 5.21.It also decreased the hardness,chewiness,and stickiness in cured pork hind legs,yielding a softer texture.In addition,it slowed the rate of color deterioration and inhibited fat oxidation.Analysis of volatile flavor compounds revealed that curdlan increased the variety of flavor compounds in cured pork hind legs by more than twenty types.The odor activity values of key aroma components(such as linalool and nonanal)also increased to varying degrees,enriching the flavor profile of the cured meat.Thus,curdlan effectively improves the texture,color,and flavor of cured pork hind legs,providing process parameters for industrial production of low-fat cured meat.
基金the National Natural Science Foundation of China, No. 30760071, 30960118Foundation of the Education Department of Jiangxi Province, No. GJJ08106Science and Technology Research Program of Nanchang University, No. J06~~
基金supported by the Korea Science and Engineering Foundation Grant(National Research Laboratory Program,R0A-2007-000-200012-0)the Korea Research Foundation(KRF-006-005-J03301)partially supported by the 2009 KU Brain Pool of Konkuk University
文摘In an attempt to realize a flapping wing micro-air vehicle with morphing wings, we report on improvements to our previousfoldable artificial hind wing.Multiple hinges, which were implemented to mimic the bending zone of a beetle hind wing, weremade of small composite hinge plates and tiny aluminum rivets.The buck-tails of rivets were flared after the hinge plates wereassembled with the rivets so that the folding/unfolding motions could be completed in less time, and the straight shape of theartificial hind wing could be maintained after fabrication.Folding and unfolding actions were triggered by electrically-activatedShape Memory Alloy (SMA) wires.For wing folding, the actuation characteristics of the SMA wire actuator were modifiedthrough heat treatment.Through a series of flapping tests, we confirmed that the artificial wings did not fold back and arbitrarilyfluctuate during the flapping motion.
基金the National Natural Science Foundation of China,No.30801171，the Natural Science Foundation of Hebei Province,No.C2009001013 and No.H2012406015
文摘Dark Agouti rat donor hind limbs were orthotopically transplanted into Lewis rat recipients to verify the effects of bone marrow mesenchymal stem cells on neural regeneration and functional recovery of allotransplanted limbs in the microenvironment of immunotolerance, bone marrow mesenchymal stem cells were intramuscularly （gluteus maximus） injected with FK506 （tacrolimus） daily, and were transplanted to the injured nerves. Results indicated that the allograft group not receiving therapy showed severe rejection, with transplanted limbs detaching at 10 days after transplantation with complete necrosis. The number of myelinated axons and Schwann cells in the FK506 and FK506 ＋ bone marrow mesenchymal stem cells groups were significantly increased. We observed a lesser degree of gastrocnemius muscle degeneration, and increased polymorphic fibers along with other pathological changes in the FK506 ＋ bone marrow mesenchymal stem cells group. The FK506 ＋ bone marrow mesenchymal stem cells group showed significantly better recovery than the autograft and FK506 groups. The results demonstrated that FK506 improved the immune microenvironment. FK506 combined with bone marrow mesenchymal stem cells significantly promoted sciatic nerve regeneration, and improved sensory recovery and motor function in hind limb allotransplant.
基金This research was funded by the the Science and Technology Development Program of Jilin Province,China(Grant No.20230101117JC)National Natural Science Foundation of China(Grant No.51775234,91748211,51305157)the Science and Technology Development Program of Jilin Province,China(Grant No.20190302101GX,20180101090JC).
文摘The goat’s hind limbs play an important role in dampening vibrations caused by ground impact during movement.Inspired by the unique structure of their hind limbs,a novel bionic limb vibration isolator has been developed to suppress low-frequency vibrations.It consists of the base,the carrying platform,four bionic legs and so on.The bionic legs are made up of rods of varying lengths and springs in different directions to imitate the various shapes of bones such as the femur and patella of the hind limbs of goats and developed muscles such as the biceps and quadriceps.The bionic device was found to have excellent nonlinear stiffness through statics analysis,and could be flexibly adjusted to the work range and load capacity.The bionic vibration isolator offers lower natural frequencies(2.3 Hz),better vibration isolation effect and a wider vibration isolation band than conventional linear vibration isolator.The bionic device can effectively suppress vibrations above 3.2 Hz and reduce the amplitude of random vibrations to more than 90%.In addition,compared to similar bionic vibration isolation devices,the bionic isolator achieves excellent load-bearing capacity in a smaller size,which facilitates its application in practical production.
