Consistent mechanical and machining properties are essential in many applications where ductile irons offer the most cost-effective way to produce structural parts.In the production of hydraulic rotators,dimensional t...Consistent mechanical and machining properties are essential in many applications where ductile irons offer the most cost-effective way to produce structural parts.In the production of hydraulic rotators,dimensional tolerances are typically 20μm to obtain designated performance.For castings where intermediate strength and ductility is required,it is common knowledge that conventional ferritic-pearlitic ductile irons such as ISO 1083/500-7 show large hardness variations.These are mainly caused by the notoriously varying pearlite content,both at different locations within a part and between parts in the same or different batches.Cooling rate variations due to different wall thickness and position in the molding box,as well as varying amounts of pearlite-stabilizing elements,all contribute to detrimental hardness variations.The obvious remedy is to avoid pearlite formation,and instead obtain the necessary mechanical properties by solution strengthening of the ferritic matrix by increasing silicon content to 3.7wt%-3.8wt%.The Swedish development in this field 1998 resulted in a national standardization as SS 140725,followed in 2004 by ISO 1083/ JS/500-10.Indexator AB decided 2005 to specify JS/500-10 for all new ductile iron parts and to convert all existing parts.Improvements include reduction by 75%in hardness variations and increase by 30%in cutting tool life,combined with consistently better mechanical properties.展开更多
Spiral polarization rotators, rotating polarization ellipse axes clockwise or counterclockwise, depending on the azimuth angle in the transverse plane, are considered. It is shown that spiral polarization rotators lea...Spiral polarization rotators, rotating polarization ellipse axes clockwise or counterclockwise, depending on the azimuth angle in the transverse plane, are considered. It is shown that spiral polarization rotators lead to a change in the order of optical vortices with circular polarization. A comparative analysis of spiral rotators of two types (polar and non-polar) is carried out, using a mirror that allows light to pass in the opposite direction through the rotator. The effect of spiral rotators on optical vortices in a resonator is studied. It is shown that spiral rotators can preserve or accumulate changes of the vortex order during the passage of the beam in both directions. The properties of the spiral rotator and the cube-corner reflector with a special phase-correcting coating, as a diffractive polarization-optical element, are compared.展开更多
Dislocations and disclinations are fundamental topological defects within crystals,which determine the mechanical properties of metals and alloys.Despite their important roles in multiple physical mechanisms,e.g.,dyna...Dislocations and disclinations are fundamental topological defects within crystals,which determine the mechanical properties of metals and alloys.Despite their important roles in multiple physical mechanisms,e.g.,dynamic recovery and grain boundary mediated plasticity,the intrinsic coupling and correlation between disclinations and dislocations,and their impacts on the deformation behavior of metallic materials still remain obscure,partially due to the lack of a theoretical tool to capture the rotational nature of disclinations.By using a Lie-algebra-based theoretical framework,we obtain a general equation to quantify the intrinsic coupling of disclinations and dislocations.Through quasi in-situ electron backscatter diffraction characterizations and disclination/dislocation density analyses in Mg alloys,the generation,coevolution and reactions of disclinations and dislocations during dynamic recovery and superplastic deformation have been quantitatively analyzed.It has been demonstrated that the obtained governing equation can capture multiple physical processes associated with mechanical deformation of metals,e.g.,grain rotation and grain boundary migration,at both room temperature and high temperature.By establishing the disclination-dislocation coupling equation within a Lie algebra description,our work provides new insights for exploring the coevolution and reaction of disclinations/dislocations,with profound implications for elucidating the microstructure-property relationship and underlying deformation mechanisms in metallic materials.展开更多
1.Introduction.Cold Spray(CS)is a highly advanced solid-state metal depo-sition process that was first developed in the 1980s.This innovative technique involves the high-speed(300-1200 m/s)impact deposition of micron-...1.Introduction.Cold Spray(CS)is a highly advanced solid-state metal depo-sition process that was first developed in the 1980s.This innovative technique involves the high-speed(300-1200 m/s)impact deposition of micron-sized particles(5-50μm)to fabricate coatings[1-3].CS has been extensively used in a variety of coating applications,such as aerospace,automotive,energy,medical,marine,and others,to provide protection against high temperatures,corrosion,erosion,oxidation,and chemicals[4,5].Nowadays,the technical interest in CS is twofold:(i)as a repair process for damaged components,and(ii)as a solid-state additive manufacturing process.Compared to other fusion-based additive manufacturing(AM)technologies,Cold Spray Additive Manufacturing(CSAM)is a new member of the AM family that can enable the fabrication of deposits without undergoing melting.The chemical composition has been largely preserved from the powder to the deposit due to the minimal oxidation.The significant advantages of CSAM over other additive manufacturing processes include a high production rate,unlimited deposition size,high flexibility,and suitability for repairing damaged parts.展开更多
Electrical energy can be harvested from the rotational kinetic energy of moving bodies,consisting of both mechanical and kinetic energy as a potential power source through electromagnetic induction,similar to wind ene...Electrical energy can be harvested from the rotational kinetic energy of moving bodies,consisting of both mechanical and kinetic energy as a potential power source through electromagnetic induction,similar to wind energy applications.In industries,rotational bodies are commonly present in operations,yet this kinetic energy remains untapped.This research explores the energy generation characteristics of two rotational body types,disk-shaped and cylinder-shaped under specific experimental setups.The hardware setup included a direct current(DC)motor driver,power supply,DC generator,mechanical support,and load resistance,while the software setup involved automation testing tools and data logging.Electromagnetic induction was used to harvest energy,and experiments were conducted at room temperature(25℃)with controlled variables like speed and friction.Results showed the disk-shaped body exhibited higher energy efficiency than the cylinder-shaped body,largely due to lower mechanical losses.The disk required only two bearings,while the cylinder required four,resulting in lower bearing losses for the disk.Additionally,the disk experienced only air friction,whereas the cylinder encountered friction from a soft,uneven rubber material,increasing surface contact losses.Under a 40 W resistive load,the disk demonstrated a 17.1%energy loss due to mechanical friction,achieving up to 15.55 J of recycled energy.Conversely,the cylinder body experienced a 48.05%energy loss,delivering only 51.95%of energy to the load.These insights suggest significant potential for designing efficient energy recycling systems in industrial settings,particularly in manufacturing and processing industries where rotational machinery is prevalent.Despite its lower energy density,this system could be beneficially integrated with energy storage solutions,enhancing sustainability in industrial practices.展开更多
This letter compares the clinical efficacy and economic feasibility of the scoliocorrector fatma-UI(SCFUI)with direct vertebral rotation(DVR)in treating adolescent idiopathic scoliosis(AIS).SCFUI has shown promising r...This letter compares the clinical efficacy and economic feasibility of the scoliocorrector fatma-UI(SCFUI)with direct vertebral rotation(DVR)in treating adolescent idiopathic scoliosis(AIS).SCFUI has shown promising results in threedimensional spinal correction,providing superior rotational alignment compared to DVR and achieving significant improvements in coronal and sagittal planes.Additionally,SCFUI’s advanced design reduces risks associated with AIS surgeries and enhances overall patient outcomes.Economic analysis reveals SCFUI as a cost-effective option,potentially lowering long-term healthcare costs by minimizing complications and revisions.Our findings suggest that SCFUI is a viable,innovative approach in AIS treatment,meeting clinical and economic demands in orthopedic care.展开更多
Osteoporosis is a known risk factor for rotator cuff tears(RCTs),but the causal correlation and underlying mechanisms remain unclear.This study aims to evaluate the impact of osteoporosis on RCT risk and investigate t...Osteoporosis is a known risk factor for rotator cuff tears(RCTs),but the causal correlation and underlying mechanisms remain unclear.This study aims to evaluate the impact of osteoporosis on RCT risk and investigate their genetic associations.Using data from the UK Biobank(n=457871),cross-sectional analyses demonstrated that osteoporosis was significantly associated with an increased risk of RCTs(adjusted OR[95%CI]=1.38[1.25–1.52]).A longitudinal analysis of a subset of patients(n=268117)over 11 years revealed that osteoporosis increased the risk of RCTs(adjusted HR[95%CI]=1.56[1.29–1.87]),which is notably varied between sexes in sex-stratified analysis.Causal inference methods,including propensity score matching,inverse probability weighting,causal random forest and survival random forest models further confirmed the causal effect,both from cross-sectional and longitudinal perspectives.展开更多
BACKGROUND Rotator cuff tears are a chief cause of shoulder pain and disability,and surgical repair is often required when conservative management fails.As digital health technologies have expanded,especially since th...BACKGROUND Rotator cuff tears are a chief cause of shoulder pain and disability,and surgical repair is often required when conservative management fails.As digital health technologies have expanded,especially since the coronavirus disease 2019 pandemic,digitally augmented rehabilitation programs emerged as a potential alternative to conventional physical therapy.AIM To determine if digitally assisted rehabilitation could be as practical,or even more effective,than the traditional methods most patients currently follow.METHODS Six electronic databases,including PubMed,Scopus,Cochrane Library,Google Scholar,EMBASE,and Web of Science,were searched to find articles that compare digital-based rehabilitation and conventional treatment.Outcomes of interest were Disabilities of the Arm,Shoulder and Hand(DASH)score and range of motion.The quality assessment of the included studies was performed using the risk-of-bias tool for randomized trials tool.RESULTS Three randomized controlled trial studies were enrolled in this study,including 195 cases.We did not find any significant differences between the two groups in terms of DASH score,flexion range of motion,and external rotation range of motion.There was a significant difference between the two groups for abduction range of motion.CONCLUSION Digital home-based rehab seems to be a strong alternative to traditional methods,offering similar results for people recovering from rotator cuff surgery.This approach might also make rehab more accessible and engaging for patients.That said,further research is needed to fully understand the potential of digital rehabilitation and ensure it works effectively for everyone.展开更多
BACKGROUND Shoulder arthroscopy is commonly used for the repair of glenohumeral ligament avulsions or tendon tears.The success of the operation depends on the ability of the ligaments or rotator cuff tendon to heal to...BACKGROUND Shoulder arthroscopy is commonly used for the repair of glenohumeral ligament avulsions or tendon tears.The success of the operation depends on the ability of the ligaments or rotator cuff tendon to heal to their original attachment site.Soft tissue healing can be evaluated with imaging methods or alternatively with second-look arthroscopy.AIM To investigate shoulder tendon and capsule healing after arthroscopic rotator cuff and instability repair using second-look arthroscopy.METHODS In this study,24 adult patients with rotator cuff tears(13 patients)or anterior shoulder instability(11 patients)were included.All patients were initially subjected to arthroscopic repair using suture anchors and were re-evaluated with second-look arthroscopy for reasons not related to the original pathology.The second operation was performed in 8 patients due to mild but persistent pain or stiffness,in 3 patients for recalcitrant stiffness,in 5 patients for secondary biceps tenotomy,in 6 patients for persistent acromioclavicular joint pain and in 2 patients for suture anchor prominence causing shoulder grinding.Soft tissue healing was evaluated visually and by probing,whereas clinical outcomes were evaluated using the University of California–Los Angeles(UCLA)and Rowe rating scales.RESULTS In almost all patients,complete soft tissue healing occurred at the site of tissue reattachment,either on the glenoid articular surface or the greater humeral tuberosity.The strongest repair,as confirmed by probe palpation,was encountered at the site of suture passage through the soft tissue.All suture material was covered with bursal synovial tissue,with no cases of knot impingement or cartilage fraying.The mean preoperative and postoperative UCLA scores for rotator cuff repair patients were 1354±3205 and 2931±2898,respectively(P<0.001),whereas for shoulder instability patients,the mean Rowe scores preoperatively and postoperatively were 2591±1338 and 9272±754,respectively(P<0.001).The use of bioabsorbable implants did not cause synovitis or other tissue reactions.CONCLUSION Soft tissue healing in the shoulder is successful and strongest at the site of suture anchor placement.展开更多
Thermal vibrational convection(TVC)refers to the time-averaged convection of a non-isothermal fluid subjected to oscillating force fields.It serves as an effective mechanism for heat transfer control,particularly unde...Thermal vibrational convection(TVC)refers to the time-averaged convection of a non-isothermal fluid subjected to oscillating force fields.It serves as an effective mechanism for heat transfer control,particularly under microgravity conditions.A key challenge in this field is understanding the effect of rotation on TVC,as fluid oscillations in rotating systems exhibit unique and specific characteristics.In this study,we examine TVC in a vertical flat layer with boundaries at different temperatures,rotating around a horizontal axis.The distinctive feature of this study is that the fluid oscillations within the cavity are not induced by vibrations of the cavity itself,but rather by the gravity field,giving them a tidal nature.Our findings reveal that inertial waves generated in the rotating layer qualitatively alter the TVC structure,producing time-averaged flows in the form of toroidal vortices.Experimental investigations of the structure of oscillatory and time-averaged flows,conducted using Particle Image Velocimetry(PIV)for flow velocity visualization,are complemented by theoretical calculations of inertial modes in a cavity with this geometry.To the best of our knowledge,this study represents the first of its kind.The agreement between experimental results and theoretical predictions confirms that the formation of convective structures in the form of toroidal vortices is driven by inertial waves induced by the gravity field.A decrease in the rotational velocity leads to a transformation of the convective structures,shifting from toroidal vortices of inertial-wave origin to classical cellular TVC.We present dimensionless parameters that define the excitation thresholds for both cellular convection and toroidal structures.展开更多
Global food production faces enormous challenges in increasing yields while promoting environmental sustainability.A field experiments in the ecotone between the Yangtze River Basin and the HuangHuai-Hai Plain evaluat...Global food production faces enormous challenges in increasing yields while promoting environmental sustainability.A field experiments in the ecotone between the Yangtze River Basin and the HuangHuai-Hai Plain evaluated the effects of changing preceding crop rotation cycles(wheat and rapeseed)on long-term wheat-rice(W)and rapeseed-rice(R)rotation systems.A comprehensive evaluation of crop rotation systems was conducted using life cycle assessment,considering productivity,economic benefits,carbon footprint(CF),and soil health.Compared with fallow-rice rotation(F),alternating rapeseed and wheat rotations increased equivalent yield by 60.4%-82.2%,reduced CF by 0.3%-5.7%,and improved soil health by 0.3%-47.5%.Additionally,adding rapeseed to rotations increased soil nutrient content and raised soil organic carbon stocks by 31.3%-40.5%.The 3R rotation(3-year rapeseed-rice and 1-year wheat-rice)boosted rice yield by 82.2%and annual economic benefits by 84.4%,offering an effective model for optimizing long-term R rotations.Similarly,the 2W rotation(2-year wheat-rice and 1-year rapeseed rice)enhanced rice yield by 70.0% and annual economic benefits by 65.9%,providing a successful example for optimizing long-term W rotations.The 3R rapeseed-based rotation and the 2W wheatbased rotation demonstrated good environmental sustainability.These rotation systems have broad potential in sustainable intensive farming,especially in China and similar regions.展开更多
The dynamics of fluid and non-buoyant particles in a librating horizontal annulus is studied experimentally.In the absence of librations,the granular material forms a cylindrical layer near the outer boundary of the a...The dynamics of fluid and non-buoyant particles in a librating horizontal annulus is studied experimentally.In the absence of librations,the granular material forms a cylindrical layer near the outer boundary of the annulus and undergoes rigid-body rotation with the fluid and the annulus.It is demonstrated that the librational liquefaction of the granular material results in pattern formation.This self-organization process stems from the excitation of inertial modes induced by the oscillatory motion of liquefied granular material under the influence of the gravitational force.The inertial wave induces vortical fluid flow which entrains particles from rest and forms eroded areas that are equidistant from each other along the axis of rotation.Theoretical analysis and experiments demonstrate that a liquefied layer of granular material oscillates with a radian frequency equal to the angular velocity of the annulus and interacts with the inertial wave it excites.The new phenomenon of libration-induced pattern formation is of practical interest as it can be used to control multiphase flows and mass transfer in rotating containers in a variety of industrial processes.展开更多
BACKGROUND Long head of biceps tendon(LHBT)transposition is a novel technique based on the double-row suture bridge method,utilizing autologous reconstruction to treat massive rotator cuff tears.AIM To evaluate the mi...BACKGROUND Long head of biceps tendon(LHBT)transposition is a novel technique based on the double-row suture bridge method,utilizing autologous reconstruction to treat massive rotator cuff tears.AIM To evaluate the mid-to-long-term clinical outcomes following the double-row repair method for massive rotator cuff tears.METHODS This retrospective analysis included data from 53 patients with massive rotator cuff tears treated at our hospital between 2020 and 2021.The patients were divided into the double-row repair group(conventional group)and the doublerow repair combined with the LHBT transposition group(transposition group).Postoperative pain was assessed using the visual analogue scale at one week,one year,and the final follow-up.Shoulder function was evaluated using the American Shoulder and Elbow Surgeons and Constant-Murley scores at one year and the final follow-up.Rotator cuff healing was assessed postoperatively for one year using the Sugaya classification,which categorizes tendon integrity based on magnetic resonance imaging findings.RESULTS No perioperative complications were observed in any of the patients at any time.There were no significant differences between the groups regarding operative time and intraoperative blood loss.The transposition group had significantly lower visual analogue scale scores than the conventional group at one week postoperatively;however,there were no significant differences between the groups at one year or the final follow-up.At one year postoperatively,the transposition group showed significantly higher American Shoulder and Elbow Surgeons and Constant-Murley scores than the conventional group;no significant differences were observed at the final followup.There were no significant differences in rotator cuff healing between the groups at one year postoperatively.CONCLUSION Compared to double-row repair alone,double-row repair combined with LHBT transposition for treating massive rotator cuff tears more effectively alleviates short-term postoperative pain and improves shoulder function within the first year.展开更多
Active matter exhibits collective motions at various scales.Geometric confinement has been identified as an effective way to control and manipulate active fluids,with much attention given to external factors.However,t...Active matter exhibits collective motions at various scales.Geometric confinement has been identified as an effective way to control and manipulate active fluids,with much attention given to external factors.However,the impact of the inherent properties of active particles on collective motion under confined conditions remains elusive.Here,we use a highly tunable active nematics model to study active systems under confinement,focusing on the effect of the self-driven speed of active particles.We identify three distinct states characterized by unique particle and flow fields within confined active nematic systems,among which circular rotation emerges as a collective motion involving rotational movement in both particle and flow fields.The theoretical phase diagram shows that increasing the self-driven speed of active particles significantly enhances the region of the circular rotation state and improves its stability.Our results provide insights into the formation of high quality vortices in confined active nematic systems.展开更多
This study focuses on coupled vibrations of rotating thin-walled composite beams subjected to hygrothermal effects.In the existing literature,many studies have been conducted on coupled bending-torsional vibration and...This study focuses on coupled vibrations of rotating thin-walled composite beams subjected to hygrothermal effects.In the existing literature,many studies have been conducted on coupled bending-torsional vibration and resonance in hygrothermal environments.Few studies considered the coupled flapwise-edgewise and resonances of composite thin-walled beams.Considering this,the flapwise-edgewise coupling effects and resonant characteristics of rotating thin-walled composite beams in a hygrothermal environment are studied.The Rayleigh–Ritz method is used to solve the equations of the beam.Results indicate that flapwise-edgewise coupling factors are essential for the vibration analysis of rectangular thin-walled beams.The ply angle and setting angle strongly affect the internal and external resonances.Large ply angles can significantly reduce the chances of primary internal and external resonances occurring when the permitted rotational speed is lower.展开更多
Diversifying crop rotation aims to balance production and ecological concerns.However,yield and water use efficiency(WUE)of crop in diversified rotation systems have not been well documented,especially under limited i...Diversifying crop rotation aims to balance production and ecological concerns.However,yield and water use efficiency(WUE)of crop in diversified rotation systems have not been well documented,especially under limited irrigation.Here,we conducted a 6-year experiment with five treatments:1)wheatmaize cropping system(WM),as control;2)WMME,spring maize→WM rotation;3)WMML,spring millet→WM rotation;4)WMMP,spring peanut→WM rotation;and 5)WMMS,spring soybean→WM rotation,to explore how diversified rotations affected yield and WUE of wheat.Results showed that approximately 60% higher precipitation during wheat growing season in Cycle 1(2015-2017)resulted in yield increases by 33.8%-55.7% compared to those in Cycle 2(2017-2019)and Cycle3(2019-2021).Grain yield and WUE of wheat were 16.7% and 9.6% higher in Cycle 1,81.5% and 86.8% higher in Cycle 2,and 56.1% and 78.7% higher in Cycle 3 on average in diversified rotations compared to those in WM,respectively.Further analysis revealed that spike number and aboveground biomass were the main contributors to the increments,which can be explained by the increased evapotranspiration during the middle-late wheat growth stages(e.g.,regreening,jointing,and anthesis)in diversified rotations.In general,diversified rotations enhanced synchronization of soil water supply with crop water demand by affecting the spatiotemporal dynamics of soil moisture under varied precipitation conditions,thereby increasing yield and WUE of wheat.Hence,diversified spring crops→WM rotations offer a sustainable and efficient strategy for enhancing wheat production and water conservation in dry areas.展开更多
Time-averaged thermal convection in a rotating horizontal annulus with a higher temperature at its inner boundary is studied.The centrifugal force plays a stabilizing role,while thermal convection is determined by the...Time-averaged thermal convection in a rotating horizontal annulus with a higher temperature at its inner boundary is studied.The centrifugal force plays a stabilizing role,while thermal convection is determined by the“thermovibrational mechanism”.Convective flow is excited due to oscillations of a non-isothermal rotating fluid.Thermal vibrational convectionmanifests in the form of two-dimensional vortices elongated along the axis of rotation,which develop in a threshold manner with an increase in the amplitude of fluid oscillations.The objective of the present study is to clarify the nature of another phenomenon,i.e.,three-dimensional convective vortices observed in the experiments both before the excitation of the convection described above and in the supercritical region.The experimental study of the oscillatory and the time-averaged flow fields by particle image velocimetry is accompanied by the theoretical research of inertial waves.It is found that three-dimensional fluid flows owe their origin to inertial waves.This is confirmed by a high degree of agreement between the experimental and theoretical results.Experiments with cavities of different lengths indicate that the vortices are clearly seen in cavities thatmeet the conditions of resonant excitation of inertial modes.Furthermore,the length of the cavity has no effect on heat transfer,which is explained by the comparatively low intensity of the wave-induced flows.The main contribution to heat transfer is due to vortices elongated along the axis of rotation.The novel results are of significant practical importance in various fields.展开更多
BACKGROUND Sub-acromial injections are a therapeutic option for rotator cuff injuries;however,evidence regarding the most effective drug in this context is unclear,which needs to be investigated.AIM To evaluate the ef...BACKGROUND Sub-acromial injections are a therapeutic option for rotator cuff injuries;however,evidence regarding the most effective drug in this context is unclear,which needs to be investigated.AIM To evaluate the effectiveness of various sub-acromial injections for rotator cuff injuries.METHODS We conducted a systematic review and pair-wise and network meta-analyses of randomized clinical trials(RCTs)comparing sub-acromial injections for rotator cuff injuries.The interventions evaluated were hyaluronic acid(HA),platelet-rich plasma(PRP),prolotherapy,and corticosteroids.The outcomes of interest were pain and functional improvement,which were evaluated with standardized scores.The Risk of Bias 2 tool and the Grading of Recommendations,Assessment,Development and Evaluation methodology were used to assess data quality.RESULTS Twenty RCTs,comprising 1479 participants,were included.In the short term,HA achieved the best outcomes[pain mean difference(MD)=-1.48,95%confidence interval(CI)-2.37 to-0.59;function MD=10.18,95%CI:4.96-15.41].In the medium term,HA,PRP,HA+PRP,and corticosteroids were not superior to placebo in improving pain.Based on function,HA+PRP was superior to placebo,corticosteroids,and PRP(MD=26.72;95%CI:8.02-45.41).In the long term,HA,PRP,and corticosteroids were not superior to placebo in reducing pain.However,based on function,HA+PRP,PRP,and HA were superior to placebo,and HA+PRP had the best result(MD=36.64;95%CI:31.66-33.62).CONCLUSION HA provides satisfactory short-term results,while HA with PRP demonstrates functional improvement in the medium and long terms.However,no intervention maintained the pain-relief effect on>3-month follow-up.展开更多
BACKGROUND Massive rotator cuff tears(RCTs)result in impaired shoulder function and quality of life.These tears lead to structural changes in the rotator cuff muscles,which compromise recovery after repair and increas...BACKGROUND Massive rotator cuff tears(RCTs)result in impaired shoulder function and quality of life.These tears lead to structural changes in the rotator cuff muscles,which compromise recovery after repair and increase re-tear rates.AIM To investigate the potential inhibitory effects of alpha-tocopherol(vitamin E)and OTR-4131 on muscle atrophy,fatty infiltration,and fibrosis in rotator cuff muscles following a massive RCT using a Wistar rat model,and establish a standardized methodology for evaluating potential therapeutic agents.METHODS This protocol outlines a controlled animal study using 40 male Wistar rats,randomized into five groups.The experimental groups will receive either systemic administration of alpha-tocopherol or local administration of OTR-4131 via intramuscular injection into the supraspinatus and infraspinatus muscles.Two sham groups will receive systemic and local saline injections respectively,while a control group will undergo no intervention.The interventions will be administered after surgical transection of the supraspinatus and infraspinatus tendons.Outcomes will be assessed via wet muscle weight measurements,muscle fiber diameter,fatty infiltration percentage,and fibrosis evaluation using histological methods.RESULTS The study anticipates that alpha-tocopherol and OTR-4131 will reduce muscle atrophy,fatty infiltration,and fibrosis compared to control and sham groups,supporting their potential protective role in rotator cuff muscle degeneration.CONCLUSION The results are expected to improve the understanding on the role of alpha-tocopherol and OTR-4131 in rotator cuff muscle protection after massive RCT and may serve as a foundation for further preclinical and clinical research aimed at improving rotator cuff repair outcomes.展开更多
文摘Consistent mechanical and machining properties are essential in many applications where ductile irons offer the most cost-effective way to produce structural parts.In the production of hydraulic rotators,dimensional tolerances are typically 20μm to obtain designated performance.For castings where intermediate strength and ductility is required,it is common knowledge that conventional ferritic-pearlitic ductile irons such as ISO 1083/500-7 show large hardness variations.These are mainly caused by the notoriously varying pearlite content,both at different locations within a part and between parts in the same or different batches.Cooling rate variations due to different wall thickness and position in the molding box,as well as varying amounts of pearlite-stabilizing elements,all contribute to detrimental hardness variations.The obvious remedy is to avoid pearlite formation,and instead obtain the necessary mechanical properties by solution strengthening of the ferritic matrix by increasing silicon content to 3.7wt%-3.8wt%.The Swedish development in this field 1998 resulted in a national standardization as SS 140725,followed in 2004 by ISO 1083/ JS/500-10.Indexator AB decided 2005 to specify JS/500-10 for all new ductile iron parts and to convert all existing parts.Improvements include reduction by 75%in hardness variations and increase by 30%in cutting tool life,combined with consistently better mechanical properties.
文摘Spiral polarization rotators, rotating polarization ellipse axes clockwise or counterclockwise, depending on the azimuth angle in the transverse plane, are considered. It is shown that spiral polarization rotators lead to a change in the order of optical vortices with circular polarization. A comparative analysis of spiral rotators of two types (polar and non-polar) is carried out, using a mirror that allows light to pass in the opposite direction through the rotator. The effect of spiral rotators on optical vortices in a resonator is studied. It is shown that spiral rotators can preserve or accumulate changes of the vortex order during the passage of the beam in both directions. The properties of the spiral rotator and the cube-corner reflector with a special phase-correcting coating, as a diffractive polarization-optical element, are compared.
基金Financial supports from the National Natural Science Foundation of China(Nos.52171116,U22A20109,52334010 and T2325013)are greatly acknowledgedPartial financial support came from The Program for the Central University Youth Innovation Team,and the Fundamental Research Funds for the Central Universities,JLU.
文摘Dislocations and disclinations are fundamental topological defects within crystals,which determine the mechanical properties of metals and alloys.Despite their important roles in multiple physical mechanisms,e.g.,dynamic recovery and grain boundary mediated plasticity,the intrinsic coupling and correlation between disclinations and dislocations,and their impacts on the deformation behavior of metallic materials still remain obscure,partially due to the lack of a theoretical tool to capture the rotational nature of disclinations.By using a Lie-algebra-based theoretical framework,we obtain a general equation to quantify the intrinsic coupling of disclinations and dislocations.Through quasi in-situ electron backscatter diffraction characterizations and disclination/dislocation density analyses in Mg alloys,the generation,coevolution and reactions of disclinations and dislocations during dynamic recovery and superplastic deformation have been quantitatively analyzed.It has been demonstrated that the obtained governing equation can capture multiple physical processes associated with mechanical deformation of metals,e.g.,grain rotation and grain boundary migration,at both room temperature and high temperature.By establishing the disclination-dislocation coupling equation within a Lie algebra description,our work provides new insights for exploring the coevolution and reaction of disclinations/dislocations,with profound implications for elucidating the microstructure-property relationship and underlying deformation mechanisms in metallic materials.
基金supported by the National Natural Science Foundation of China(No.52061135101 and 52001078)the German Research Foundation(DFG,No.448318292)+3 种基金the Technology Innovation Guidance Special Foundation of Shaanxi Province(No.2023GXLH-085)the Fundamental Research Funds for the Central Universities(No.D5000240161)the Project of Key areas of innovation team in Shaanxi Province(No.2024RS-CXTD-20)The author Yingchun Xie thanks the support from the National Key R&D Program(No.2023YFE0108000).
文摘1.Introduction.Cold Spray(CS)is a highly advanced solid-state metal depo-sition process that was first developed in the 1980s.This innovative technique involves the high-speed(300-1200 m/s)impact deposition of micron-sized particles(5-50μm)to fabricate coatings[1-3].CS has been extensively used in a variety of coating applications,such as aerospace,automotive,energy,medical,marine,and others,to provide protection against high temperatures,corrosion,erosion,oxidation,and chemicals[4,5].Nowadays,the technical interest in CS is twofold:(i)as a repair process for damaged components,and(ii)as a solid-state additive manufacturing process.Compared to other fusion-based additive manufacturing(AM)technologies,Cold Spray Additive Manufacturing(CSAM)is a new member of the AM family that can enable the fabrication of deposits without undergoing melting.The chemical composition has been largely preserved from the powder to the deposit due to the minimal oxidation.The significant advantages of CSAM over other additive manufacturing processes include a high production rate,unlimited deposition size,high flexibility,and suitability for repairing damaged parts.
基金The APC was funded by Research Management Center, Multimedia University, Malaysia.
文摘Electrical energy can be harvested from the rotational kinetic energy of moving bodies,consisting of both mechanical and kinetic energy as a potential power source through electromagnetic induction,similar to wind energy applications.In industries,rotational bodies are commonly present in operations,yet this kinetic energy remains untapped.This research explores the energy generation characteristics of two rotational body types,disk-shaped and cylinder-shaped under specific experimental setups.The hardware setup included a direct current(DC)motor driver,power supply,DC generator,mechanical support,and load resistance,while the software setup involved automation testing tools and data logging.Electromagnetic induction was used to harvest energy,and experiments were conducted at room temperature(25℃)with controlled variables like speed and friction.Results showed the disk-shaped body exhibited higher energy efficiency than the cylinder-shaped body,largely due to lower mechanical losses.The disk required only two bearings,while the cylinder required four,resulting in lower bearing losses for the disk.Additionally,the disk experienced only air friction,whereas the cylinder encountered friction from a soft,uneven rubber material,increasing surface contact losses.Under a 40 W resistive load,the disk demonstrated a 17.1%energy loss due to mechanical friction,achieving up to 15.55 J of recycled energy.Conversely,the cylinder body experienced a 48.05%energy loss,delivering only 51.95%of energy to the load.These insights suggest significant potential for designing efficient energy recycling systems in industrial settings,particularly in manufacturing and processing industries where rotational machinery is prevalent.Despite its lower energy density,this system could be beneficially integrated with energy storage solutions,enhancing sustainability in industrial practices.
文摘This letter compares the clinical efficacy and economic feasibility of the scoliocorrector fatma-UI(SCFUI)with direct vertebral rotation(DVR)in treating adolescent idiopathic scoliosis(AIS).SCFUI has shown promising results in threedimensional spinal correction,providing superior rotational alignment compared to DVR and achieving significant improvements in coronal and sagittal planes.Additionally,SCFUI’s advanced design reduces risks associated with AIS surgeries and enhances overall patient outcomes.Economic analysis reveals SCFUI as a cost-effective option,potentially lowering long-term healthcare costs by minimizing complications and revisions.Our findings suggest that SCFUI is a viable,innovative approach in AIS treatment,meeting clinical and economic demands in orthopedic care.
基金the Scientific Research Innovation Capability Support Project for Young Faculty(ZYGXQNJSKYCXNLZCXM-H8)Fundamental Research Funds for the Central Universities(2024ZYGXZR077)+3 种基金Guangdong Basic and Applied Basic Research Foundation(2023B1515120006)Guangzhou Basic and Applied Basic Research Foundation(2024A04J5776)the Research Fund(2023QN10Y421)Guangzhou Talent Recruitment Team Program(2024D03J0004),all related to this study.
文摘Osteoporosis is a known risk factor for rotator cuff tears(RCTs),but the causal correlation and underlying mechanisms remain unclear.This study aims to evaluate the impact of osteoporosis on RCT risk and investigate their genetic associations.Using data from the UK Biobank(n=457871),cross-sectional analyses demonstrated that osteoporosis was significantly associated with an increased risk of RCTs(adjusted OR[95%CI]=1.38[1.25–1.52]).A longitudinal analysis of a subset of patients(n=268117)over 11 years revealed that osteoporosis increased the risk of RCTs(adjusted HR[95%CI]=1.56[1.29–1.87]),which is notably varied between sexes in sex-stratified analysis.Causal inference methods,including propensity score matching,inverse probability weighting,causal random forest and survival random forest models further confirmed the causal effect,both from cross-sectional and longitudinal perspectives.
文摘BACKGROUND Rotator cuff tears are a chief cause of shoulder pain and disability,and surgical repair is often required when conservative management fails.As digital health technologies have expanded,especially since the coronavirus disease 2019 pandemic,digitally augmented rehabilitation programs emerged as a potential alternative to conventional physical therapy.AIM To determine if digitally assisted rehabilitation could be as practical,or even more effective,than the traditional methods most patients currently follow.METHODS Six electronic databases,including PubMed,Scopus,Cochrane Library,Google Scholar,EMBASE,and Web of Science,were searched to find articles that compare digital-based rehabilitation and conventional treatment.Outcomes of interest were Disabilities of the Arm,Shoulder and Hand(DASH)score and range of motion.The quality assessment of the included studies was performed using the risk-of-bias tool for randomized trials tool.RESULTS Three randomized controlled trial studies were enrolled in this study,including 195 cases.We did not find any significant differences between the two groups in terms of DASH score,flexion range of motion,and external rotation range of motion.There was a significant difference between the two groups for abduction range of motion.CONCLUSION Digital home-based rehab seems to be a strong alternative to traditional methods,offering similar results for people recovering from rotator cuff surgery.This approach might also make rehab more accessible and engaging for patients.That said,further research is needed to fully understand the potential of digital rehabilitation and ensure it works effectively for everyone.
文摘BACKGROUND Shoulder arthroscopy is commonly used for the repair of glenohumeral ligament avulsions or tendon tears.The success of the operation depends on the ability of the ligaments or rotator cuff tendon to heal to their original attachment site.Soft tissue healing can be evaluated with imaging methods or alternatively with second-look arthroscopy.AIM To investigate shoulder tendon and capsule healing after arthroscopic rotator cuff and instability repair using second-look arthroscopy.METHODS In this study,24 adult patients with rotator cuff tears(13 patients)or anterior shoulder instability(11 patients)were included.All patients were initially subjected to arthroscopic repair using suture anchors and were re-evaluated with second-look arthroscopy for reasons not related to the original pathology.The second operation was performed in 8 patients due to mild but persistent pain or stiffness,in 3 patients for recalcitrant stiffness,in 5 patients for secondary biceps tenotomy,in 6 patients for persistent acromioclavicular joint pain and in 2 patients for suture anchor prominence causing shoulder grinding.Soft tissue healing was evaluated visually and by probing,whereas clinical outcomes were evaluated using the University of California–Los Angeles(UCLA)and Rowe rating scales.RESULTS In almost all patients,complete soft tissue healing occurred at the site of tissue reattachment,either on the glenoid articular surface or the greater humeral tuberosity.The strongest repair,as confirmed by probe palpation,was encountered at the site of suture passage through the soft tissue.All suture material was covered with bursal synovial tissue,with no cases of knot impingement or cartilage fraying.The mean preoperative and postoperative UCLA scores for rotator cuff repair patients were 1354±3205 and 2931±2898,respectively(P<0.001),whereas for shoulder instability patients,the mean Rowe scores preoperatively and postoperatively were 2591±1338 and 9272±754,respectively(P<0.001).The use of bioabsorbable implants did not cause synovitis or other tissue reactions.CONCLUSION Soft tissue healing in the shoulder is successful and strongest at the site of suture anchor placement.
基金funded by the Ministry of Education of the Russian Federation within the framework of a state assignment,number 1023032300071-6-2.3.1.
文摘Thermal vibrational convection(TVC)refers to the time-averaged convection of a non-isothermal fluid subjected to oscillating force fields.It serves as an effective mechanism for heat transfer control,particularly under microgravity conditions.A key challenge in this field is understanding the effect of rotation on TVC,as fluid oscillations in rotating systems exhibit unique and specific characteristics.In this study,we examine TVC in a vertical flat layer with boundaries at different temperatures,rotating around a horizontal axis.The distinctive feature of this study is that the fluid oscillations within the cavity are not induced by vibrations of the cavity itself,but rather by the gravity field,giving them a tidal nature.Our findings reveal that inertial waves generated in the rotating layer qualitatively alter the TVC structure,producing time-averaged flows in the form of toroidal vortices.Experimental investigations of the structure of oscillatory and time-averaged flows,conducted using Particle Image Velocimetry(PIV)for flow velocity visualization,are complemented by theoretical calculations of inertial modes in a cavity with this geometry.To the best of our knowledge,this study represents the first of its kind.The agreement between experimental results and theoretical predictions confirms that the formation of convective structures in the form of toroidal vortices is driven by inertial waves induced by the gravity field.A decrease in the rotational velocity leads to a transformation of the convective structures,shifting from toroidal vortices of inertial-wave origin to classical cellular TVC.We present dimensionless parameters that define the excitation thresholds for both cellular convection and toroidal structures.
基金supported by the National Natural Science Foundation of China(31971855)the Agricultural Science and Technology Innovation Project of the Chinese Academy of Agricultural Science(CAAS-ASTIP-2021-OCRI)+2 种基金the Hubei Provincial Natural Science Foundation of China(2024AFB442)the Wuhan Knowledge Innovation Special Program(2023020201020400)the China Agriculture Research System(CARS-12)。
文摘Global food production faces enormous challenges in increasing yields while promoting environmental sustainability.A field experiments in the ecotone between the Yangtze River Basin and the HuangHuai-Hai Plain evaluated the effects of changing preceding crop rotation cycles(wheat and rapeseed)on long-term wheat-rice(W)and rapeseed-rice(R)rotation systems.A comprehensive evaluation of crop rotation systems was conducted using life cycle assessment,considering productivity,economic benefits,carbon footprint(CF),and soil health.Compared with fallow-rice rotation(F),alternating rapeseed and wheat rotations increased equivalent yield by 60.4%-82.2%,reduced CF by 0.3%-5.7%,and improved soil health by 0.3%-47.5%.Additionally,adding rapeseed to rotations increased soil nutrient content and raised soil organic carbon stocks by 31.3%-40.5%.The 3R rotation(3-year rapeseed-rice and 1-year wheat-rice)boosted rice yield by 82.2%and annual economic benefits by 84.4%,offering an effective model for optimizing long-term R rotations.Similarly,the 2W rotation(2-year wheat-rice and 1-year rapeseed rice)enhanced rice yield by 70.0% and annual economic benefits by 65.9%,providing a successful example for optimizing long-term W rotations.The 3R rapeseed-based rotation and the 2W wheatbased rotation demonstrated good environmental sustainability.These rotation systems have broad potential in sustainable intensive farming,especially in China and similar regions.
基金funded by the Ministry of Education of the Russian Federation within the framework of a state assignment,number 1023032300071-6-2.3.1.
文摘The dynamics of fluid and non-buoyant particles in a librating horizontal annulus is studied experimentally.In the absence of librations,the granular material forms a cylindrical layer near the outer boundary of the annulus and undergoes rigid-body rotation with the fluid and the annulus.It is demonstrated that the librational liquefaction of the granular material results in pattern formation.This self-organization process stems from the excitation of inertial modes induced by the oscillatory motion of liquefied granular material under the influence of the gravitational force.The inertial wave induces vortical fluid flow which entrains particles from rest and forms eroded areas that are equidistant from each other along the axis of rotation.Theoretical analysis and experiments demonstrate that a liquefied layer of granular material oscillates with a radian frequency equal to the angular velocity of the annulus and interacts with the inertial wave it excites.The new phenomenon of libration-induced pattern formation is of practical interest as it can be used to control multiphase flows and mass transfer in rotating containers in a variety of industrial processes.
基金Supported by the General Program of the Hubei Provincial Natural Science Foundation of China Key Project,No.2021CFB520.
文摘BACKGROUND Long head of biceps tendon(LHBT)transposition is a novel technique based on the double-row suture bridge method,utilizing autologous reconstruction to treat massive rotator cuff tears.AIM To evaluate the mid-to-long-term clinical outcomes following the double-row repair method for massive rotator cuff tears.METHODS This retrospective analysis included data from 53 patients with massive rotator cuff tears treated at our hospital between 2020 and 2021.The patients were divided into the double-row repair group(conventional group)and the doublerow repair combined with the LHBT transposition group(transposition group).Postoperative pain was assessed using the visual analogue scale at one week,one year,and the final follow-up.Shoulder function was evaluated using the American Shoulder and Elbow Surgeons and Constant-Murley scores at one year and the final follow-up.Rotator cuff healing was assessed postoperatively for one year using the Sugaya classification,which categorizes tendon integrity based on magnetic resonance imaging findings.RESULTS No perioperative complications were observed in any of the patients at any time.There were no significant differences between the groups regarding operative time and intraoperative blood loss.The transposition group had significantly lower visual analogue scale scores than the conventional group at one week postoperatively;however,there were no significant differences between the groups at one year or the final follow-up.At one year postoperatively,the transposition group showed significantly higher American Shoulder and Elbow Surgeons and Constant-Murley scores than the conventional group;no significant differences were observed at the final followup.There were no significant differences in rotator cuff healing between the groups at one year postoperatively.CONCLUSION Compared to double-row repair alone,double-row repair combined with LHBT transposition for treating massive rotator cuff tears more effectively alleviates short-term postoperative pain and improves shoulder function within the first year.
基金supported by the National Key Research and Development Program of China under Grant No.2022YFA1405000Innovation Program for Quantum Science and Technology under Grant No.2024ZD0300101the National Natural Science Foundation of China under Grant Nos.12274212,12174184,12347102。
文摘Active matter exhibits collective motions at various scales.Geometric confinement has been identified as an effective way to control and manipulate active fluids,with much attention given to external factors.However,the impact of the inherent properties of active particles on collective motion under confined conditions remains elusive.Here,we use a highly tunable active nematics model to study active systems under confinement,focusing on the effect of the self-driven speed of active particles.We identify three distinct states characterized by unique particle and flow fields within confined active nematic systems,among which circular rotation emerges as a collective motion involving rotational movement in both particle and flow fields.The theoretical phase diagram shows that increasing the self-driven speed of active particles significantly enhances the region of the circular rotation state and improves its stability.Our results provide insights into the formation of high quality vortices in confined active nematic systems.
基金supported by the National Natural Science Foundation of China(Grant Nos.11902002 and 51705002)the Sichuan Provincial Natural Science Foundation(Grant No.2022NSFSC0275)the University Outstanding Youth Researcher Support Program of the Education Department of Anhui Province,and the Teaching Project of the Education Department of Anhui Province(Grant No.2022xxsfkc023).
文摘This study focuses on coupled vibrations of rotating thin-walled composite beams subjected to hygrothermal effects.In the existing literature,many studies have been conducted on coupled bending-torsional vibration and resonance in hygrothermal environments.Few studies considered the coupled flapwise-edgewise and resonances of composite thin-walled beams.Considering this,the flapwise-edgewise coupling effects and resonant characteristics of rotating thin-walled composite beams in a hygrothermal environment are studied.The Rayleigh–Ritz method is used to solve the equations of the beam.Results indicate that flapwise-edgewise coupling factors are essential for the vibration analysis of rectangular thin-walled beams.The ply angle and setting angle strongly affect the internal and external resonances.Large ply angles can significantly reduce the chances of primary internal and external resonances occurring when the permitted rotational speed is lower.
基金supported by the National Natural Science Foundation of China(32172125 and U21A20218)。
文摘Diversifying crop rotation aims to balance production and ecological concerns.However,yield and water use efficiency(WUE)of crop in diversified rotation systems have not been well documented,especially under limited irrigation.Here,we conducted a 6-year experiment with five treatments:1)wheatmaize cropping system(WM),as control;2)WMME,spring maize→WM rotation;3)WMML,spring millet→WM rotation;4)WMMP,spring peanut→WM rotation;and 5)WMMS,spring soybean→WM rotation,to explore how diversified rotations affected yield and WUE of wheat.Results showed that approximately 60% higher precipitation during wheat growing season in Cycle 1(2015-2017)resulted in yield increases by 33.8%-55.7% compared to those in Cycle 2(2017-2019)and Cycle3(2019-2021).Grain yield and WUE of wheat were 16.7% and 9.6% higher in Cycle 1,81.5% and 86.8% higher in Cycle 2,and 56.1% and 78.7% higher in Cycle 3 on average in diversified rotations compared to those in WM,respectively.Further analysis revealed that spike number and aboveground biomass were the main contributors to the increments,which can be explained by the increased evapotranspiration during the middle-late wheat growth stages(e.g.,regreening,jointing,and anthesis)in diversified rotations.In general,diversified rotations enhanced synchronization of soil water supply with crop water demand by affecting the spatiotemporal dynamics of soil moisture under varied precipitation conditions,thereby increasing yield and WUE of wheat.Hence,diversified spring crops→WM rotations offer a sustainable and efficient strategy for enhancing wheat production and water conservation in dry areas.
基金funded by the Ministry of Education of the Russian Federation within the framework of a state assignment,number 1023032300071-6-2.3.1.
文摘Time-averaged thermal convection in a rotating horizontal annulus with a higher temperature at its inner boundary is studied.The centrifugal force plays a stabilizing role,while thermal convection is determined by the“thermovibrational mechanism”.Convective flow is excited due to oscillations of a non-isothermal rotating fluid.Thermal vibrational convectionmanifests in the form of two-dimensional vortices elongated along the axis of rotation,which develop in a threshold manner with an increase in the amplitude of fluid oscillations.The objective of the present study is to clarify the nature of another phenomenon,i.e.,three-dimensional convective vortices observed in the experiments both before the excitation of the convection described above and in the supercritical region.The experimental study of the oscillatory and the time-averaged flow fields by particle image velocimetry is accompanied by the theoretical research of inertial waves.It is found that three-dimensional fluid flows owe their origin to inertial waves.This is confirmed by a high degree of agreement between the experimental and theoretical results.Experiments with cavities of different lengths indicate that the vortices are clearly seen in cavities thatmeet the conditions of resonant excitation of inertial modes.Furthermore,the length of the cavity has no effect on heat transfer,which is explained by the comparatively low intensity of the wave-induced flows.The main contribution to heat transfer is due to vortices elongated along the axis of rotation.The novel results are of significant practical importance in various fields.
文摘BACKGROUND Sub-acromial injections are a therapeutic option for rotator cuff injuries;however,evidence regarding the most effective drug in this context is unclear,which needs to be investigated.AIM To evaluate the effectiveness of various sub-acromial injections for rotator cuff injuries.METHODS We conducted a systematic review and pair-wise and network meta-analyses of randomized clinical trials(RCTs)comparing sub-acromial injections for rotator cuff injuries.The interventions evaluated were hyaluronic acid(HA),platelet-rich plasma(PRP),prolotherapy,and corticosteroids.The outcomes of interest were pain and functional improvement,which were evaluated with standardized scores.The Risk of Bias 2 tool and the Grading of Recommendations,Assessment,Development and Evaluation methodology were used to assess data quality.RESULTS Twenty RCTs,comprising 1479 participants,were included.In the short term,HA achieved the best outcomes[pain mean difference(MD)=-1.48,95%confidence interval(CI)-2.37 to-0.59;function MD=10.18,95%CI:4.96-15.41].In the medium term,HA,PRP,HA+PRP,and corticosteroids were not superior to placebo in improving pain.Based on function,HA+PRP was superior to placebo,corticosteroids,and PRP(MD=26.72;95%CI:8.02-45.41).In the long term,HA,PRP,and corticosteroids were not superior to placebo in reducing pain.However,based on function,HA+PRP,PRP,and HA were superior to placebo,and HA+PRP had the best result(MD=36.64;95%CI:31.66-33.62).CONCLUSION HA provides satisfactory short-term results,while HA with PRP demonstrates functional improvement in the medium and long terms.However,no intervention maintained the pain-relief effect on>3-month follow-up.
基金thank the staff of the accredited animal facility of the laboratory of anatomy,Histology and Embryology of Aristotle University of Thessaloniki’s veterinary school for their assistance in animal handling and care.
文摘BACKGROUND Massive rotator cuff tears(RCTs)result in impaired shoulder function and quality of life.These tears lead to structural changes in the rotator cuff muscles,which compromise recovery after repair and increase re-tear rates.AIM To investigate the potential inhibitory effects of alpha-tocopherol(vitamin E)and OTR-4131 on muscle atrophy,fatty infiltration,and fibrosis in rotator cuff muscles following a massive RCT using a Wistar rat model,and establish a standardized methodology for evaluating potential therapeutic agents.METHODS This protocol outlines a controlled animal study using 40 male Wistar rats,randomized into five groups.The experimental groups will receive either systemic administration of alpha-tocopherol or local administration of OTR-4131 via intramuscular injection into the supraspinatus and infraspinatus muscles.Two sham groups will receive systemic and local saline injections respectively,while a control group will undergo no intervention.The interventions will be administered after surgical transection of the supraspinatus and infraspinatus tendons.Outcomes will be assessed via wet muscle weight measurements,muscle fiber diameter,fatty infiltration percentage,and fibrosis evaluation using histological methods.RESULTS The study anticipates that alpha-tocopherol and OTR-4131 will reduce muscle atrophy,fatty infiltration,and fibrosis compared to control and sham groups,supporting their potential protective role in rotator cuff muscle degeneration.CONCLUSION The results are expected to improve the understanding on the role of alpha-tocopherol and OTR-4131 in rotator cuff muscle protection after massive RCT and may serve as a foundation for further preclinical and clinical research aimed at improving rotator cuff repair outcomes.
