Ankle snapping occurs when tendons or retinacular structures abruptly move or slip over adjacent anatomical structures,often due to anatomical variations,pathological conditions,or acute injury.This phenomenon can cau...Ankle snapping occurs when tendons or retinacular structures abruptly move or slip over adjacent anatomical structures,often due to anatomical variations,pathological conditions,or acute injury.This phenomenon can cause pain and discomfort,ranging from mild irritation to debilitating symptoms that potentially disrupt daily activities and athletic pursuits.Considering the anatomy of the ankle,these snapping phenomena can be categorized into four regional groups:(1)Lateral;(2)Medial;(3)Anterior;and(4)Posterior.Lateral ankle snapping,a common occurrence,typically results from peroneal tendon subluxation due to compromise of the superior and inferior peroneal retinacula,or from intrasheath subluxation,characterized by abnormal tendon motion within an otherwise intact retromalleolar groove and retinaculum.Medial ankle snapping primarily affects the posterior tibial tendon and can involve the flexor digitorum longus tendon.Anterior ankle snapping results from abnormal gliding of the tibialis anterior tendon,extensor digitorum longus tendon,peroneus tertius tendon,and inferior extensor retinaculum.Posterior ankle snapping typically involves the plantaris tendon and flexor hallucis longus(hallux saltans).This mini-review comprehensively explores these snapping phenomena and their related pathologies in the foot and ankle,emphasizing the crucial roles of anatomical knowledge,thorough clinical assessment,and appropriate diagnostic and treatment approaches.展开更多
This is a correction to:Isabela R R Moraes,Mariana Antunes,Laura S Lopez-Greco,Fernando Jose Zara,Antonio Leao Castilho,Functional reproductive morphology of the snapping shrimp genus Synalpheus Spence Bate,1888(Decap...This is a correction to:Isabela R R Moraes,Mariana Antunes,Laura S Lopez-Greco,Fernando Jose Zara,Antonio Leao Castilho,Functional reproductive morphology of the snapping shrimp genus Synalpheus Spence Bate,1888(Decapoda,Alpheidae),Current Zoology,2024,71,338-352;https:/doi.org/10.1093/cz/zoae053.展开更多
BACKGROUND A snapping wrist is a rare symptom that results from the sudden impingement of one anatomic structure against another,subsequently causing a sudden movement only during wrist movement.CASE SUMMARY A 30-year...BACKGROUND A snapping wrist is a rare symptom that results from the sudden impingement of one anatomic structure against another,subsequently causing a sudden movement only during wrist movement.CASE SUMMARY A 30-year-old woman with a history of right wrist contusion reported right wrist snapping after overuse.The snapping became symptomatic after moving heavy objects.The pain persisted even when she received 1 mo of conservative treatment.Physical examination showed painful wrist snapping during wrist radioulnar motion and thumb abduction-adduction.Radiography demonstrated bone overgrowth over the radial styloid process.Sonography disclosed a tendon jumping over a bony prominence in the first compartment during wrist motion.Magnetic resonance imaging revealed no anomalous tendon nor tumorlike lesion.Under the wide-awake local anesthesia no tourniquet(WALANT)technique,the lesion was identified in the first extensor compartment.The patient received stepwise extensor retinaculum release,synovectomy,and bone spur removal.By 6th week,the patient was completely free of pain and unable to snap her wrist.She started working 7 wk after the surgery.One year after the surgery,the wrist snap was not recurrent.CONCLUSION Careful physical examination and dynamic sonography may confirm the diagnosis of a snapping wrist.With the WALANT technique,the lesion could be identified under direct vision,and we could take stepwise interventions according to intraoperative presentations.展开更多
An analysis of buckling/snapping and bending behaviors of magneto-elastic-plastic interaction and coupling for cantilever rectangular soft ferromagnetic plates is presented. Based on the expression of magnetic force f...An analysis of buckling/snapping and bending behaviors of magneto-elastic-plastic interaction and coupling for cantilever rectangular soft ferromagnetic plates is presented. Based on the expression of magnetic force from the variational principle of ferromagnetic plates, the buckling and bending theory of thin plates, the Mises yield criterion and the increment theory for plastic deformation, we establish a numerical code to quantitatively simulate the behaviors of the nonlinearly multi-fields coupling problems by the finite element method. Along with the phenomena of buckling/snapping and bending, or the characteristic curve of deflection versus magnitude of applied magnetic fields being numerically displayed, the critical loads of buckling/snapping, and the influences of plastic deformation and the width of plate on these critical loads, the plastic regions expanding with the magnitude of applied magnetic field, as well as the evolvement of deflection configuration of the plate are numerically obtained in a case study.展开更多
AIM To review current literature on types of distal triceps injuryand determine diagnosis and appropriate management.METHODS We performed a systematic review in PubM ed, Cochrane and EMBASE using the terms distal tric...AIM To review current literature on types of distal triceps injuryand determine diagnosis and appropriate management.METHODS We performed a systematic review in PubM ed, Cochrane and EMBASE using the terms distal triceps tears and snapping triceps on the 10 th January 2017. We excluded all animal, review, foreign language and repeat papers. We reviewed all papers for relevance and of the papers left we were able to establish the types of distal triceps injury, how these injuries are diagnosed and investigated and the types of management of these injuries including surgical. The results are then presented in a review paper format.RESULTS Three hundred and seventy-nine papers were identified of which 65 were relevant to distal triceps injuries. After exclusion we had 47 appropriate papers. The papers highlighted 2 main distal triceps injuries: Distal triceps tears and snapping triceps. Triceps tear are more common in males than females occurring in the 4th-5th decade of life and often due to a direct trauma but are also strongly associated with weightlifting and American football. The tears are diagnosed by history and clinically with a palpable gap. Diagnosis can be confirmed with the use of ultrasound(US) and magnetic resonance imaging. Treatment depends on type of tear. Partial tears can be treated conservatively with bracing and physio whereas acute tears need repair either open or arthroscopic using suture anchor or bone tunnel techniques with similar success. Chronic tears often need augmenting with tendon allograft or autograft. Snapping triceps are also seen more in men than women but at a mean age of 32 years. They are characterized by a snapping sensation mostly medially and can be associated with ulna nerve subluxation and ulna nerve symptoms. US is the diagnostic modality of choice due to its dynamic nature and to differentiate between snapping triceps tendon or ulna nerve. Treatment is conservative initially with activity avoidance and if that fails surgical management includes resection of triceps edge or transposition of the tendon plus or minusulna nerve transposition.CONCLUSION Distal triceps injuries are uncommon. This systematic review examines the evidence base behind diagnosis, imaging and treatment options of distal triceps injuries including tears and snapping triceps.展开更多
Tensegrities are a class of lightweight and reticulated structures consisting of stressed strings and bars. It is shown that each prismatic tensegrity can have two self-equilibrated and stable states, leading to a sna...Tensegrities are a class of lightweight and reticulated structures consisting of stressed strings and bars. It is shown that each prismatic tensegrity can have two self-equilibrated and stable states, leading to a snapping instability behavior under an applied torque. The predicted mechanism is experimentally validated, and can be used in areas such as advanced sensors and actuators, energy storage /alsorption equipments, and folding/unfolding devices.展开更多
AIM To develop practical guidelines for diagnosis and treatment of the painful snapping elbow syndrome(SE). METHODS Clinical studies were searched in the databases Pub Med and Scopus for the phrases "SE", &q...AIM To develop practical guidelines for diagnosis and treatment of the painful snapping elbow syndrome(SE). METHODS Clinical studies were searched in the databases Pub Med and Scopus for the phrases "SE", "snapping triceps", "snapping ulnar nerve" and "snapping annular ligament". A total of 36 relevant studies were identified. From these we extracted information about number of patients, diagnostic methods, patho-anatomical findings, treatments and outcomes. Practical guidelines for diagnosis and treatment of SE were developed based on analysis of the data. We present two illustrative patient cases-one with intra-articular pathology and one with extra-articular pathology.RESULTS Snapping is audible, palpable and often visible. It has a lateral(intra-articular) or medial(extra-articular) pathology. Snapping over the medial humeral epicondyle is caused by dislocation of the ulnar nerve or a part of the triceps tendon, and is demonstrated by dynamic ultrasonography. Treatment is by open surgery. Lateral snapping over the radial head has an intra-articular pathology: A synovial plica, a torn annular ligament or a meniscus-like remnant from the foetal elbow. Pathology can be visualized by conventional arthrography, magnetic resonance(MR) arthrography, high resolution magnetic resonance imaging(MRI) and arthroscopy, while conventional MRI and radiographs often turn out normal. Treatment is by arthroscopic or eventual open resection. Early surgical intervention is recommended asthe snapping can damage the ulnar nerve(medial) or the intra-articular cartilage(lateral). If medial snapping only occurs during repeated or loaded extension/flexion of the elbow(in sports or work) it may be treated by reduction of these activities. Differential diagnoses are loose bodies(which can be visualized by radiographs) and postero-lateral instability(demonstrates by clinical examination). An algorithm for diagnosis and treatment is suggested.CONCLUSION The primary step is establishment of laterality. From this follows relevant diagnostic measures and treatment as defined in this guideline.展开更多
By the improvement of Riks’and Crisfield’s arc-length method,the adaptiveparameter incremental method is preasted for predicting the snapping response ofstructures. Its justification is fulfilled. Finally,the effect...By the improvement of Riks’and Crisfield’s arc-length method,the adaptiveparameter incremental method is preasted for predicting the snapping response ofstructures. Its justification is fulfilled. Finally,the effectiveness of this method isdemonstrated by solving the snapping response of spherical caps subjected to centrallydistributed pressures.展开更多
BACKGROUND Snapping triceps syndrome(STS)is a rare disease,while occurrence of bilateral STS is extremely rare.It is usually accompanied by dislocation of the ulnar nerve and double snapping is a clinically important ...BACKGROUND Snapping triceps syndrome(STS)is a rare disease,while occurrence of bilateral STS is extremely rare.It is usually accompanied by dislocation of the ulnar nerve and double snapping is a clinically important feature.However,to the best of our knowledge,there has been no report of bilateral STS in young active patient.CASE SUMMARY A 23-year-old male presented with a complaint of discomfort and snapping on the medial side of both elbows while performing push-ups.On physical examination,two distinct snaps that were both palpable and audible were detected on additional clinical examination.Dynamic ultrasonography showed that the ulnar nerve and the medial head of the triceps were dislocated anteriorly over the medial epicondyle of the elbow during flexion motion.Finally,he was diagnosed as dislocation of the ulnar nerve and STS.Staged anterior subcutaneous transposition of the ulnar nerve combined with partial resection of the snapping portion of the triceps was performed.The patient’s pain and snapping symptoms were resolved immediately after surgery.Three months later,the patient was completely asymptomatic and returned to normal activity.CONCLUSION STS should be included in the differential diagnosis for active young patients who present with painful snapping on the medial side of the elbow joint,particularly when dislocation of the ulnar nerve is detected.Dynamic sonography is used to assist in accurate diagnosis and differentiation between isolated dislocation of the ulnar nerve and STS.展开更多
The blocking between two snapping rollers will seriously constrict the harvesting efficiency for corn harvester.A variable screw pitch rib snapping roller was developed to solve this problem.The comparative experiment...The blocking between two snapping rollers will seriously constrict the harvesting efficiency for corn harvester.A variable screw pitch rib snapping roller was developed to solve this problem.The comparative experiment between fixed screw pitch rib snapping rollers and variable screw pitch rib snapping rollers illustrated that variable screw pitch ribs can avoid corn-stalk blocking effectively,and it can improve working efficiency by 56.7%.Conservation tillage with standing corn residue was testified that it had a strong control of soil wind erosion.In order to implement this mode of conservation tillage at a production scale,a cutter was developed in this study.Subsequently,two experiments were conducted,one was to test the cutting ratio(defined as the totally cut off stalk population divided by total stalk population),and the other one was to test standing-residue height.The experiment results showed that the mean cutting ratio increased significantly(p<0.05)along with increasing height of cutter-head above the ground(cutting height);the cutting ratio’s mean value increased significantly(p<0.05)along with the decreasing angle between the cutter-head and the ground(cutting angle).The average standing-residue height increased along with the increase of cutting height from 300 mm to 500 mm.The average standing-residue height increased significantly(p<0.05)along with the decrease of cutting angle from 15°to 0°.Therefore,the newly designed snapping roller can improve the harvesting efficiency and prolong the working life of the cutting table;and the cutter can promote the popularization of the conservation tillage with standing corn residue in Northeast China.展开更多
Science flow cytometry measurement of intensity is relative measur, ement. The standards are therefore necessary. There are two types of standards. One is the instrumental standard for adjustment FCM. Fluorescent micr...Science flow cytometry measurement of intensity is relative measur, ement. The standards are therefore necessary. There are two types of standards. One is the instrumental standard for adjustment FCM. Fluorescent microspheres or glutaraldehyde fixed chicken red blood cells are commonly used for this purpose. The other is the DNA internal standard of nuclear DNA ploidy analysis for correcting the changes in preparation and staining condition and instrument drift during measurement.展开更多
BACKGROUND Hepatic ischemia-reperfusion(I/R)injury related to liver transplantation and hepatic resection remains a challenge in clinical practice.Accumulating evidence indicates that mitochondrial dysfunction is a cr...BACKGROUND Hepatic ischemia-reperfusion(I/R)injury related to liver transplantation and hepatic resection remains a challenge in clinical practice.Accumulating evidence indicates that mitochondrial dysfunction is a critical cause of I/R injury.The protein 4-nitrophenylphosphatase domain and non-neuronal SNAP25-like protein homolog 1(NIPSNAP1)is involved in the regulation of mitophagy and the recruitment of autophagy receptor proteins independent of PTEN induced putative kinase 1.AIM To clarify the protective mechanism of NIPSNAP1 against hepatic I/R,with a focus on mitophagy and mitochondrial dynamics,as well as the potential mechanism by which n6-methyladenosine(m6A)modification regulates NIPSNAP1.METHODS Mice were administered an adeno-associated virus in vivo and a hepatic I/R model was established via portal vein interruption followed by reperfusion to explore the effect of NIPSNAP1 on hepatic I/R.HepG2 cells were subjected to hypoxia/reoxygenation treatment in vitro.RESULTS We observed a significant downregulation of both NIPSNAP1 and insulin-like growth factor 2 mRNA-binding protein 2(IGF2BP2)expression in vivo and in vitro.NIPSNAP1 knockdown impaired mitophagy and disrupted mitochondrial dynamics;in contrast,NIPSNAP1 overexpression resulted in the opposite effects.Further studies revealed that IGF2BP2 functions as an m6A reader that targets and binds NIPSNAP1,thereby regulating its mRNA stability.CONCLUSION NIPSNAP1 prevents hepatic I/R injury by promoting mitophagy and maintaining mitochondrial homeostasis,serving as a novel target of the m6A reader IGF2BP2.Therefore,targeting the IGF2BP2/NIPSNAP1 axis may facilitate the development of better therapeutics for hepatic I/R.展开更多
文摘Ankle snapping occurs when tendons or retinacular structures abruptly move or slip over adjacent anatomical structures,often due to anatomical variations,pathological conditions,or acute injury.This phenomenon can cause pain and discomfort,ranging from mild irritation to debilitating symptoms that potentially disrupt daily activities and athletic pursuits.Considering the anatomy of the ankle,these snapping phenomena can be categorized into four regional groups:(1)Lateral;(2)Medial;(3)Anterior;and(4)Posterior.Lateral ankle snapping,a common occurrence,typically results from peroneal tendon subluxation due to compromise of the superior and inferior peroneal retinacula,or from intrasheath subluxation,characterized by abnormal tendon motion within an otherwise intact retromalleolar groove and retinaculum.Medial ankle snapping primarily affects the posterior tibial tendon and can involve the flexor digitorum longus tendon.Anterior ankle snapping results from abnormal gliding of the tibialis anterior tendon,extensor digitorum longus tendon,peroneus tertius tendon,and inferior extensor retinaculum.Posterior ankle snapping typically involves the plantaris tendon and flexor hallucis longus(hallux saltans).This mini-review comprehensively explores these snapping phenomena and their related pathologies in the foot and ankle,emphasizing the crucial roles of anatomical knowledge,thorough clinical assessment,and appropriate diagnostic and treatment approaches.
文摘This is a correction to:Isabela R R Moraes,Mariana Antunes,Laura S Lopez-Greco,Fernando Jose Zara,Antonio Leao Castilho,Functional reproductive morphology of the snapping shrimp genus Synalpheus Spence Bate,1888(Decapoda,Alpheidae),Current Zoology,2024,71,338-352;https:/doi.org/10.1093/cz/zoae053.
文摘BACKGROUND A snapping wrist is a rare symptom that results from the sudden impingement of one anatomic structure against another,subsequently causing a sudden movement only during wrist movement.CASE SUMMARY A 30-year-old woman with a history of right wrist contusion reported right wrist snapping after overuse.The snapping became symptomatic after moving heavy objects.The pain persisted even when she received 1 mo of conservative treatment.Physical examination showed painful wrist snapping during wrist radioulnar motion and thumb abduction-adduction.Radiography demonstrated bone overgrowth over the radial styloid process.Sonography disclosed a tendon jumping over a bony prominence in the first compartment during wrist motion.Magnetic resonance imaging revealed no anomalous tendon nor tumorlike lesion.Under the wide-awake local anesthesia no tourniquet(WALANT)technique,the lesion was identified in the first extensor compartment.The patient received stepwise extensor retinaculum release,synovectomy,and bone spur removal.By 6th week,the patient was completely free of pain and unable to snap her wrist.She started working 7 wk after the surgery.One year after the surgery,the wrist snap was not recurrent.CONCLUSION Careful physical examination and dynamic sonography may confirm the diagnosis of a snapping wrist.With the WALANT technique,the lesion could be identified under direct vision,and we could take stepwise interventions according to intraoperative presentations.
基金Project supported by the National Natural Sciences Fund of China(Nos.10302009 and 10672070)the Natural Sciences Fund of Gansu Province(3ZS051-A25-012)the Excellent Doctors' Fund of Lanzhou University
文摘An analysis of buckling/snapping and bending behaviors of magneto-elastic-plastic interaction and coupling for cantilever rectangular soft ferromagnetic plates is presented. Based on the expression of magnetic force from the variational principle of ferromagnetic plates, the buckling and bending theory of thin plates, the Mises yield criterion and the increment theory for plastic deformation, we establish a numerical code to quantitatively simulate the behaviors of the nonlinearly multi-fields coupling problems by the finite element method. Along with the phenomena of buckling/snapping and bending, or the characteristic curve of deflection versus magnitude of applied magnetic fields being numerically displayed, the critical loads of buckling/snapping, and the influences of plastic deformation and the width of plate on these critical loads, the plastic regions expanding with the magnitude of applied magnetic field, as well as the evolvement of deflection configuration of the plate are numerically obtained in a case study.
文摘AIM To review current literature on types of distal triceps injuryand determine diagnosis and appropriate management.METHODS We performed a systematic review in PubM ed, Cochrane and EMBASE using the terms distal triceps tears and snapping triceps on the 10 th January 2017. We excluded all animal, review, foreign language and repeat papers. We reviewed all papers for relevance and of the papers left we were able to establish the types of distal triceps injury, how these injuries are diagnosed and investigated and the types of management of these injuries including surgical. The results are then presented in a review paper format.RESULTS Three hundred and seventy-nine papers were identified of which 65 were relevant to distal triceps injuries. After exclusion we had 47 appropriate papers. The papers highlighted 2 main distal triceps injuries: Distal triceps tears and snapping triceps. Triceps tear are more common in males than females occurring in the 4th-5th decade of life and often due to a direct trauma but are also strongly associated with weightlifting and American football. The tears are diagnosed by history and clinically with a palpable gap. Diagnosis can be confirmed with the use of ultrasound(US) and magnetic resonance imaging. Treatment depends on type of tear. Partial tears can be treated conservatively with bracing and physio whereas acute tears need repair either open or arthroscopic using suture anchor or bone tunnel techniques with similar success. Chronic tears often need augmenting with tendon allograft or autograft. Snapping triceps are also seen more in men than women but at a mean age of 32 years. They are characterized by a snapping sensation mostly medially and can be associated with ulna nerve subluxation and ulna nerve symptoms. US is the diagnostic modality of choice due to its dynamic nature and to differentiate between snapping triceps tendon or ulna nerve. Treatment is conservative initially with activity avoidance and if that fails surgical management includes resection of triceps edge or transposition of the tendon plus or minusulna nerve transposition.CONCLUSION Distal triceps injuries are uncommon. This systematic review examines the evidence base behind diagnosis, imaging and treatment options of distal triceps injuries including tears and snapping triceps.
基金supported by the National Natural Science Foundation of China(Nos.11432008 and11502016)the China Postdoctoral Science Foundation(No.2015M570035)+1 种基金the Tsinghua University Initiative Scientific Research Program(No.20121087991)the Fundamental Research Funds for the Central Universities of China(No.FRF-TP-15-029A1)
文摘Tensegrities are a class of lightweight and reticulated structures consisting of stressed strings and bars. It is shown that each prismatic tensegrity can have two self-equilibrated and stable states, leading to a snapping instability behavior under an applied torque. The predicted mechanism is experimentally validated, and can be used in areas such as advanced sensors and actuators, energy storage /alsorption equipments, and folding/unfolding devices.
文摘AIM To develop practical guidelines for diagnosis and treatment of the painful snapping elbow syndrome(SE). METHODS Clinical studies were searched in the databases Pub Med and Scopus for the phrases "SE", "snapping triceps", "snapping ulnar nerve" and "snapping annular ligament". A total of 36 relevant studies were identified. From these we extracted information about number of patients, diagnostic methods, patho-anatomical findings, treatments and outcomes. Practical guidelines for diagnosis and treatment of SE were developed based on analysis of the data. We present two illustrative patient cases-one with intra-articular pathology and one with extra-articular pathology.RESULTS Snapping is audible, palpable and often visible. It has a lateral(intra-articular) or medial(extra-articular) pathology. Snapping over the medial humeral epicondyle is caused by dislocation of the ulnar nerve or a part of the triceps tendon, and is demonstrated by dynamic ultrasonography. Treatment is by open surgery. Lateral snapping over the radial head has an intra-articular pathology: A synovial plica, a torn annular ligament or a meniscus-like remnant from the foetal elbow. Pathology can be visualized by conventional arthrography, magnetic resonance(MR) arthrography, high resolution magnetic resonance imaging(MRI) and arthroscopy, while conventional MRI and radiographs often turn out normal. Treatment is by arthroscopic or eventual open resection. Early surgical intervention is recommended asthe snapping can damage the ulnar nerve(medial) or the intra-articular cartilage(lateral). If medial snapping only occurs during repeated or loaded extension/flexion of the elbow(in sports or work) it may be treated by reduction of these activities. Differential diagnoses are loose bodies(which can be visualized by radiographs) and postero-lateral instability(demonstrates by clinical examination). An algorithm for diagnosis and treatment is suggested.CONCLUSION The primary step is establishment of laterality. From this follows relevant diagnostic measures and treatment as defined in this guideline.
文摘By the improvement of Riks’and Crisfield’s arc-length method,the adaptiveparameter incremental method is preasted for predicting the snapping response ofstructures. Its justification is fulfilled. Finally,the effectiveness of this method isdemonstrated by solving the snapping response of spherical caps subjected to centrallydistributed pressures.
文摘BACKGROUND Snapping triceps syndrome(STS)is a rare disease,while occurrence of bilateral STS is extremely rare.It is usually accompanied by dislocation of the ulnar nerve and double snapping is a clinically important feature.However,to the best of our knowledge,there has been no report of bilateral STS in young active patient.CASE SUMMARY A 23-year-old male presented with a complaint of discomfort and snapping on the medial side of both elbows while performing push-ups.On physical examination,two distinct snaps that were both palpable and audible were detected on additional clinical examination.Dynamic ultrasonography showed that the ulnar nerve and the medial head of the triceps were dislocated anteriorly over the medial epicondyle of the elbow during flexion motion.Finally,he was diagnosed as dislocation of the ulnar nerve and STS.Staged anterior subcutaneous transposition of the ulnar nerve combined with partial resection of the snapping portion of the triceps was performed.The patient’s pain and snapping symptoms were resolved immediately after surgery.Three months later,the patient was completely asymptomatic and returned to normal activity.CONCLUSION STS should be included in the differential diagnosis for active young patients who present with painful snapping on the medial side of the elbow joint,particularly when dislocation of the ulnar nerve is detected.Dynamic sonography is used to assist in accurate diagnosis and differentiation between isolated dislocation of the ulnar nerve and STS.
基金The authors acknowledge that this work was supported by the 12th Five Year National Science and Technology Support Plan(Grant No.:2014BAD06B03)the Science and Technology Development Program of Jilin Province(Grant No.:20130204038NY and 20140309001NY)Special thanks are given to China Scholarship Council(Grant No.:201406170102).
文摘The blocking between two snapping rollers will seriously constrict the harvesting efficiency for corn harvester.A variable screw pitch rib snapping roller was developed to solve this problem.The comparative experiment between fixed screw pitch rib snapping rollers and variable screw pitch rib snapping rollers illustrated that variable screw pitch ribs can avoid corn-stalk blocking effectively,and it can improve working efficiency by 56.7%.Conservation tillage with standing corn residue was testified that it had a strong control of soil wind erosion.In order to implement this mode of conservation tillage at a production scale,a cutter was developed in this study.Subsequently,two experiments were conducted,one was to test the cutting ratio(defined as the totally cut off stalk population divided by total stalk population),and the other one was to test standing-residue height.The experiment results showed that the mean cutting ratio increased significantly(p<0.05)along with increasing height of cutter-head above the ground(cutting height);the cutting ratio’s mean value increased significantly(p<0.05)along with the decreasing angle between the cutter-head and the ground(cutting angle).The average standing-residue height increased along with the increase of cutting height from 300 mm to 500 mm.The average standing-residue height increased significantly(p<0.05)along with the decrease of cutting angle from 15°to 0°.Therefore,the newly designed snapping roller can improve the harvesting efficiency and prolong the working life of the cutting table;and the cutter can promote the popularization of the conservation tillage with standing corn residue in Northeast China.
基金Project supported by the National Natural Science Foundation of China.
文摘Science flow cytometry measurement of intensity is relative measur, ement. The standards are therefore necessary. There are two types of standards. One is the instrumental standard for adjustment FCM. Fluorescent microspheres or glutaraldehyde fixed chicken red blood cells are commonly used for this purpose. The other is the DNA internal standard of nuclear DNA ploidy analysis for correcting the changes in preparation and staining condition and instrument drift during measurement.
基金Supported by the National Natural Science Foundation of China,No.82200658.
文摘BACKGROUND Hepatic ischemia-reperfusion(I/R)injury related to liver transplantation and hepatic resection remains a challenge in clinical practice.Accumulating evidence indicates that mitochondrial dysfunction is a critical cause of I/R injury.The protein 4-nitrophenylphosphatase domain and non-neuronal SNAP25-like protein homolog 1(NIPSNAP1)is involved in the regulation of mitophagy and the recruitment of autophagy receptor proteins independent of PTEN induced putative kinase 1.AIM To clarify the protective mechanism of NIPSNAP1 against hepatic I/R,with a focus on mitophagy and mitochondrial dynamics,as well as the potential mechanism by which n6-methyladenosine(m6A)modification regulates NIPSNAP1.METHODS Mice were administered an adeno-associated virus in vivo and a hepatic I/R model was established via portal vein interruption followed by reperfusion to explore the effect of NIPSNAP1 on hepatic I/R.HepG2 cells were subjected to hypoxia/reoxygenation treatment in vitro.RESULTS We observed a significant downregulation of both NIPSNAP1 and insulin-like growth factor 2 mRNA-binding protein 2(IGF2BP2)expression in vivo and in vitro.NIPSNAP1 knockdown impaired mitophagy and disrupted mitochondrial dynamics;in contrast,NIPSNAP1 overexpression resulted in the opposite effects.Further studies revealed that IGF2BP2 functions as an m6A reader that targets and binds NIPSNAP1,thereby regulating its mRNA stability.CONCLUSION NIPSNAP1 prevents hepatic I/R injury by promoting mitophagy and maintaining mitochondrial homeostasis,serving as a novel target of the m6A reader IGF2BP2.Therefore,targeting the IGF2BP2/NIPSNAP1 axis may facilitate the development of better therapeutics for hepatic I/R.
