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
7039 Al alloys are widely used in armor vehicles,given the material’s high specific strength and fracture toughness.However,laminar tearing in the thickness plane of the base metal(BM),specifically in the normal dire...7039 Al alloys are widely used in armor vehicles,given the material’s high specific strength and fracture toughness.However,laminar tearing in the thickness plane of the base metal(BM),specifically in the normal direction(ND)and rolling direction(RD)plane,was occasionally observed after the welding of thick plates,resulting in premature material failure.A vertically metal-inert gas(MIG)-welded laminar tearing component of a 30 mm thick plate was analyzed to determine the factors associated with this phenomenon.The texture,residual stress,microhardness,and tensile properties were also investigated.The results indicated that the crack extended along the RD as a transcrystalline fracture and terminated at the BM.The grains near the crack grew preferentially in the(001)crystal direction.Furthermore,the tensile strength(83 MPa)and elongation(6.8%)in the RD were relatively higher than those in the ND.In particular,the primary factors for crack initiation include stronger texture,higher dislocation density,increased Al_(7)Cu_(2)Fe phases,lower proportion of small-angle grain boundaries,and varying grain sizes in different regions,leading to the fragile microstructure.The higher residual stress of the BM promotes the formation and extension of cracks.The restraining force due to fixation and welding shrinkage force transformed the crack into laminar tearing.Preventive measures of laminar tearing were also proposed.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
Subduction zones are major convergent boundaries,where the downgoing oceanic plates usually form continuous tabular slabs extending deep into the Earth’s interior.However,many subducting slabs especially those with y...Subduction zones are major convergent boundaries,where the downgoing oceanic plates usually form continuous tabular slabs extending deep into the Earth’s interior.However,many subducting slabs especially those with young ages,exhibit complex geometry,with varying degrees of influence on the overlying continent and surface environment.To better understand the mechanism of such slab deformation,we apply four-dimensional finite element geodynamic models with data assimilation to investigate the evolution of the Cocos subduction in Central America,where a double-slab configuration with complex tearing has recently been observed.We reproduce the subduction history of the Cocos slab since the Eocene.During this period,multiple episodes of tearing occurred within the Cocos slab,starting at 25 Ma.We find that the ancient Farallon slab,subducted during the Mesozoic,enhances the lateral pressure gradient across the slab hinge,promoting eastward mantle flow and tearing of the Cocos slab.The repeated tearing and subduction of the young Cocos plate have shaped the complex slab configuration in the region.展开更多
A rotating neoclassical tearing mode(NTM)can increase the trapped ion losses when the frequency of the NTM is close to the precessional frequency of the trapped particles.When an equilibrium electric field,produced by...A rotating neoclassical tearing mode(NTM)can increase the trapped ion losses when the frequency of the NTM is close to the precessional frequency of the trapped particles.When an equilibrium electric field,produced by the rotation of the plasma and the density gradient,is present,the average precessional frequency of the trapped ions changes and so does the mode frequency corresponding to the maximum loss rate.Our results show that when an electric field with a value of 11.2 kV/m at q=2 is included the maximum of the trapped ion losses increases from 27% to 30% based on EAST equilibrium.展开更多
The Main Himalayan Thrust(MHT),where the 2015 MW7.8 Gorkha earthquake occurred,features the most seismicity of any structure in Nepal.The structural complexity of the MHT makes it difficult to obtain a definitive inte...The Main Himalayan Thrust(MHT),where the 2015 MW7.8 Gorkha earthquake occurred,features the most seismicity of any structure in Nepal.The structural complexity of the MHT makes it difficult to obtain a definitive interpretation of deep seismogenic structures.The application of new methods and data in this region is necessary to enhance local seismic hazard analyses.In this study,we used a well-designed machine learning-based earthquake location workflow(LOC-FLOW),which incorporates machine learning phase picking,phase association,absolute location,and double-difference relative location,to process seismic data collected by the Hi-CLIMB and NAMASTE seismic networks.We built a high-precision earthquake catalog of both the quiet-period and aftershock seismicity in this region.The seismicity distribution suggests that the quietperiod seismicity(388 events)was controlled by a mid-crustal ramp and the aftershock seismicity(12,669 events)was controlled by several geological structures of the MHT.The higher-level detail of the catalogs derived from this machine learning method reveal clearer structural characteristics,showing how the flat-ramp geometry and a possible duplex structure affect the depth distribution of the seismic events,and how a tear fault changes this distribution along strike.展开更多
In the author list,the corresponding author indicator(*)was inadvertently omitted from HOU Zengqian’s name.This has now been corrected to:“HOU Zengqian¹,*”.The online version of this article was corrected.
Unintended dural tear(DT)is not an infrequent complication of biportal percutaneous endoscopic spinal surgery(BESS).DT manifests in neurological deficits,including seizure,headache,and intracranial hemorrhage.Meanwhil...Unintended dural tear(DT)is not an infrequent complication of biportal percutaneous endoscopic spinal surgery(BESS).DT manifests in neurological deficits,including seizure,headache,and intracranial hemorrhage.Meanwhile,DT may be a risk of emergence agitation(EA)after BESS,which has not yet been reported.We presented a case of a 55-year-old man with L5-S1 intervertebral disc herniation receiving BESS under general anesthesia.A DT about 3-4 mm occurred during the operation,and was repaired immediately.The patient presented EA shouting for a headache after the surgery in post anesthesia care unit(PACU).Sedative agents(midazolam,propofol and dexmedetomidine)were used,only continuously infusion of dexmedetomidine for about 4 h successfully improved EA in PACU.He had no neurologic deficits in following 3 months.This case report highlights the risk of EA when a DT occurs during BESS.Adequate sedation in early phase is critical to resolve the mass effect caused by EA.展开更多
In order to solve the issues concerning high hot tearing susceptibility(HTS)of Mg-Al-Ca series alloys,a rotating magnetic field(RMF)was applied during their solidification.The effect of RMF at different excitation cur...In order to solve the issues concerning high hot tearing susceptibility(HTS)of Mg-Al-Ca series alloys,a rotating magnetic field(RMF)was applied during their solidification.The effect of RMF at different excitation current intensities(50 A,100 A,and 150 A)on the solidification and hot tearing behavior of AXJ530(Mg-5Al-3Ca-0.17Sr)alloy was investigated.The results indicated that the HTS of AXJ530 alloy decreased with the increase of excitation current intensity.This aspect can be attributed to significant grain refinement under the action of RMF,which improved the intergranular bonding and relieved the stress concentration.On the other hand,the stirring effect of the electromagnetic force on the melt could break up the developed dendrites and delay the dendrite coherence,as well as optimize the feeding channels and improve the feeding drive of the residual liquid at the end of solidification.Therefore,under the action of RMF,the hot tearing initiation of the alloy was suppressed and the feeding efficiency of the liquid was greatly improved,which led to a noticeable reduction of the HTS of the alloy.Moreover,no significant hot tearing was detected in castings at the excitation current parameters of 150 A and 10 Hz.展开更多
Tearing modes may play an important role in the density limit disruption.The Magnetohydrodynamic(MHD)code CLT with impurity modules is used to study the tearing mode excited and driven by impurity radiation.The impuri...Tearing modes may play an important role in the density limit disruption.The Magnetohydrodynamic(MHD)code CLT with impurity modules is used to study the tearing mode excited and driven by impurity radiation.The impurity radiation can lead to plasma contraction and local enhancement of the current density.When the locally enhanced region of the current density approaches to the resonance surface,the tearing mode can be excited,even if the tearing mode is stable in the initial equilibrium.Through a scan of the initial atomic number(Z)and impurity concentrations,it is found that impurities with different Z values exhibit similar behaviors in the radiation-driven tearing mode.The impurity radiation can drive tearing mode growth through temperature cooling near the resonance surface,and there exists a linear relationship between the temperature perturbation caused by impurity radiation and the linear growth rate of the tearing mode.Additionally,the impurity can promote the growth of magnetic islands through the radiation cooling inside the magnetic island,and there exists a correlation between the initial parameters of impurity and the width of the saturated magnetic island.展开更多
The influence of pouring temperature and mold temperature on the fluidity and hot tearing behavior of Al-2Li-2Cu-0.5Mg-0.15Sc-0.1Zr-0.1Ti alloys was investigated by experimental investigation and simulation assessment...The influence of pouring temperature and mold temperature on the fluidity and hot tearing behavior of Al-2Li-2Cu-0.5Mg-0.15Sc-0.1Zr-0.1Ti alloys was investigated by experimental investigation and simulation assessment.The results showed that the length of the spiral fluidity sample increases from 302 to 756 mm as the pouring temperature increases from 680 to 740℃,and from 293 to 736 mm as the mold temperature increases from 200 to 400℃.The hot tearing susceptibility(HTS)firstly decreases and then increases with increasing pouring and mold temperatures,which is mainly caused by the oxide inclusion originating from the high activity of Li at excessive pouring temperature.Excessive pouring and mold temperatures easily produce oxide inclusions and holes,leading to a reduction in fluidity and an increase in HTS of the alloy.Combining the experimental and simulation results,the optimized pouring and mold temperatures are~720℃ and~300℃ for the cast Al-Li alloy,respectively.展开更多
This systematic review and meta-analysis evaluated the impact of a restrictive episiotomy protocol on the incidence of severe perineal tears in first vaginal deliveries. A comprehensive search was conducted in Pub Med...This systematic review and meta-analysis evaluated the impact of a restrictive episiotomy protocol on the incidence of severe perineal tears in first vaginal deliveries. A comprehensive search was conducted in Pub Med, CENTRAL, Embase, Latin American and Caribbean Health Sciences Literature and Clinical Trials. gov until June 2024. The study followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was registered in PROSPERO(CRD42024550295). Randomised controlled trials comparing restrictive episiotomy(for foetal indications only) with selective episiotomy in first-time vaginal deliveries were included. Two reviewers independently extracted data, assessed bias using the Cochrane Risk of Bias tool and conducted assessment according to Grading of Recommendations Assessment, Development and Evaluation(GRADE). Statistical analyses were performed using R(v.4.4.0) and Rev Man(v.8.6.1). Two trials with a total of 785 participants met the inclusion criteria. The restrictive episiotomy group showed a 51.8% reduction in severe perineal tears(risk ratio(RR)=0.50, 95% CI 0.21 to 1.21), though this result was not statistically significant. Episiotomy rates were lower in the restrictive group(RR=0.61, 95% CI 0.49 to 0.76). There were no significant differences in minor perineal tears, intact perineum rates or neonatal outcomes between the two groups. Despite the lack of statistical significance in the reduction of severe perineal tear occurrence, the findings suggest a trend towards improved perineal outcomes with restrictive episiotomy. Additionally, given the potential physical and psychological consequences of episiotomies, limiting their use to foetal indications may be beneficial. Further research is needed to confirm these findings and guide clinical practice.展开更多
AIM:To evaluate parameters measured using the tear film imager(TFI)prototype,a new technology that enables to quantify the tear film thickness of lipid and mucoaqueous layers.METHODS:In this cross-sectional study,pati...AIM:To evaluate parameters measured using the tear film imager(TFI)prototype,a new technology that enables to quantify the tear film thickness of lipid and mucoaqueous layers.METHODS:In this cross-sectional study,patients with dry eye,meibomian gland dysfunction(MGD),and non-dry eye/MGD from February 2020 to January 2021 were analyzed.Quantified TFI outputs included lipid layer thickness(LLT),mucoaqueous layer thickness(MALT),MALT rate of change(MALTR),and lipid breakup time.Two other interferometry devices,LipiView2 and DR-1α,were used for comparison.TFI outputs and other clinical parameters were analyzed using correlation coefficients.Each patient underwent one or several study visits.Baseline values of three device outputs,other clinical parameters,and their changes were examined.RESULTS:This study involved 28 patients(8 patients with dry eyes,13 with MGD,and 7 with non-dry eye/MGD).Baseline TFI,LipiView2,and DR-1αvalues were associated with various clinical parameters.The LLT values estimated using TFI had a correlation with the plugging score in the upper eyelid(r=−0.42).Several TFI values have correlated better than LipiView2 and DR-1α,particularly with questionnaire scores.MALTR by TFI revealed a correlation between standardized patient evaluation on eye dryness(SPEED)and dry eye-related quality of life score(DEQS)scores(r=0.59,0.43),respectively.CONCLUSION:TFI enabled to quantify the LLT and MALT separately over time and shows the moderate correlations between TFI measurements and clinical parameters,which yields the potential for TFI to serve as a complementary tool for assessing dry eye and MGD.展开更多
Cemental tear is a rare and indetectable condition unless obvious clinical signs present with the involvement of surrounding periodontal and periapical tissues. Due to its clinical manifestations similar to common den...Cemental tear is a rare and indetectable condition unless obvious clinical signs present with the involvement of surrounding periodontal and periapical tissues. Due to its clinical manifestations similar to common dental issues, such as vertical root fracture,primary endodontic diseases, and periodontal diseases, as well as the low awareness of cemental tear for clinicians, misdiagnosis often occurs. The critical principle for cemental tear treatment is to remove torn fragments, and overlooking fragments leads to futile therapy, which could deteriorate the conditions of the affected teeth. Therefore, accurate diagnosis and subsequent appropriate interventions are vital for managing cemental tear. Novel diagnostic tools, including cone-beam computed tomography(CBCT), microscopes, and enamel matrix derivatives, have improved early detection and management, enhancing tooth retention. The implementation of standardized diagnostic criteria and treatment protocols, combined with improved clinical awareness among dental professionals, serves to mitigate risks of diagnostic errors and suboptimal therapeutic interventions. This expert consensus reviewed the epidemiology, pathogenesis, potential predisposing factors, clinical manifestations, diagnosis,differential diagnosis, treatment, and prognosis of cemental tear, aiming to provide a clinical guideline and facilitate clinicians to have a better understanding of cemental tear.展开更多
Hot tearing is often a major casting defect in magnesium alloys and has a significant impact on the quality of their casting products.Hot tearing of magnesium alloys is a complex solidification phenomenon which is sti...Hot tearing is often a major casting defect in magnesium alloys and has a significant impact on the quality of their casting products.Hot tearing of magnesium alloys is a complex solidification phenomenon which is still not fully understood,it is of great importance to investigate the hot tearing behaviour of magnesium alloys.This review attempts to summarize the investigations on hot tearing of magnesium alloys over the past decades.The hot tearing criteria including recently developed Kou’s criterion are summarized and compared.The numeric simulation and assessing methods of hot tearing,factors influencing hot tearing,and hot tearing susceptibility(HTS)of magnesium alloys are discussed.展开更多
BACKGROUND Arthroscopic procedures are commonly performed for rotator cuff pathology.Repair of rotator cuff tears is a commonly performed procedure.The intraoperative evaluation of the tear size and pattern contribute...BACKGROUND Arthroscopic procedures are commonly performed for rotator cuff pathology.Repair of rotator cuff tears is a commonly performed procedure.The intraoperative evaluation of the tear size and pattern contributes to the choice and completion of the technique and the prognosis of the repair.AIM To compare the arthroscopic and open measurements with the real dimensions of three different patterns of simulated rotator cuff tears of known size using a plastic shoulder model.METHODS We created three sizes and patterns of simulated supraspinatus tears on a plastic shoulder model(small and large U-shaped,oval-shaped).Six orthopaedic surgeons with three levels of experience measured the dimensions of the tears arthroscopically,using a 5 mm probe,repeating the procedure three times,and then using a ruler(open technique).Arthroscopic,open and computerized measurements were compared.RESULTS A constant underestimation of specific dimensions of the tears was found when measured with an arthroscope,compared to both the open and computerized measurements(mean differences up to-7.5±5.8 mm,P<0.001).No differences were observed between the open and computerized measurements(mean difference-0.4±1.6 mm).The accuracy of arthroscopic and open measurements was 90.5%and 98.5%,respectively.When comparing between levels of experience,senior residents reported smaller tear dimensions when compared both to staff surgeons and fellows.CONCLUSION This study suggests that arthroscopic measurements of full-thickness rotator cuff tears constantly underestimate the dimensions of the tears.Development of more precise arthroscopic techniques or tools for the evaluation of the size and type of rotator cuff tears are necessary.展开更多
Pouring and mold temperatures are two important parameters during casting magnesium components. The present study examined their influence on hot tearing susceptibility （HTS） of commercial AZ91D and newly developed ...Pouring and mold temperatures are two important parameters during casting magnesium components. The present study examined their influence on hot tearing susceptibility （HTS） of commercial AZ91D and newly developed Mg-3Nd-0.2Zn-Zr （mass fraction, %; NZ30K） magnesium alloys in gravity permanent mold casting condition. The results indicate that mold temperature shows much more significant influence on the HTS of both alloys than pouring temperature whose influence only can be distinguished at low mold temperature （341 K for AZ91D alloy and 423 K for NZ30K alloy）. Hot tearing susceptibility prediction model concerning feeding parameters, grain size and solidification range, is more suitable to estimate the HTS of different magnesium alloys than the model only concerning feeding parameters. In order to achieve better hot tearing resistance, the ranges of pouring and mold temperatures are suggested to be 961-991 K and≥641 K for AZ91D alloy, 1003-1033 K and≥623 K for NZ30K alloy, respectively.展开更多
The solidification characteristics and the hot tearing susceptibility were investigated on two Ni-based superalloys for turbocharger turbine wheel, K418 and K419. The segregation behaviors of the alloying elements and...The solidification characteristics and the hot tearing susceptibility were investigated on two Ni-based superalloys for turbocharger turbine wheel, K418 and K419. The segregation behaviors of the alloying elements and the precipitation phases were also studied. The results show that the solidification behavior of K419 alloy is complicated when compared with K418 due to the interdendritic segregation of many kinds of strong interdendritic partitioning elements in the remaining liquid at the final stage of solidification. The segregation of multiple elements in interdendritic liquid results in an extremely low solidus in K419. A long residual liquid stage is found during the solidification of K419, giving rise to reduced cohesion strength of dendrites and increased sensitivity to hot tearing. A hot tearing susceptibility coefficient（HTS） criterion is proposed based on a hot tearing sensitive model. The HTS value of K419 alloy is larger than that of K418 alloy.展开更多
The instrumented applied rod casting apparatus （ARCA） was developed to investigate the effects of tensile forces in the hot tearing formation of cast AI-Si alloys. The obtained data of tensile forces/temperature was...The instrumented applied rod casting apparatus （ARCA） was developed to investigate the effects of tensile forces in the hot tearing formation of cast AI-Si alloys. The obtained data of tensile forces/temperature was used to identify hot tearing initiation and propagation and the fracture surface of samples was also investigated. The result shows that the applied tensile forces have a complex effect on load onset for the hot tearing initiation and propagation. During the casting solidification, the tensile forces are gradually increased with the increase of solid fraction. Under the action of tensile forces, there will appear hot tearing and crack propagation on the surface of the sample. When the tensile forces exceed the inherent strength of alloys, there will be fractures on the sample. As for the A356 alloy, the critical fracture stress is about 0.1 MPa. The hot tearing surface morphology shows that the remaining intergranular bridge and liquid films are thick enough to allow the formation of dendrite-tip bumps on the fracture surface.展开更多
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.
基金supported by the National Key Research and Development Program of China(No.SQ2021YFF 0600011).
文摘7039 Al alloys are widely used in armor vehicles,given the material’s high specific strength and fracture toughness.However,laminar tearing in the thickness plane of the base metal(BM),specifically in the normal direction(ND)and rolling direction(RD)plane,was occasionally observed after the welding of thick plates,resulting in premature material failure.A vertically metal-inert gas(MIG)-welded laminar tearing component of a 30 mm thick plate was analyzed to determine the factors associated with this phenomenon.The texture,residual stress,microhardness,and tensile properties were also investigated.The results indicated that the crack extended along the RD as a transcrystalline fracture and terminated at the BM.The grains near the crack grew preferentially in the(001)crystal direction.Furthermore,the tensile strength(83 MPa)and elongation(6.8%)in the RD were relatively higher than those in the ND.In particular,the primary factors for crack initiation include stronger texture,higher dislocation density,increased Al_(7)Cu_(2)Fe phases,lower proportion of small-angle grain boundaries,and varying grain sizes in different regions,leading to the fragile microstructure.The higher residual stress of the BM promotes the formation and extension of cracks.The restraining force due to fixation and welding shrinkage force transformed the crack into laminar tearing.Preventive measures of laminar tearing were also proposed.
文摘Yesterday I lost my favorite watch.It was a gift from my grandfather.I was so sad and worried.I looked for it here and there,but I just couldn't find.
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.
基金supported by the Strategy Priority Research Program(Category B)of the Chinese Academy of Sciences(Grant No.XDB0710000)the National Natural Science Foundation of China(Grant No.92355302)supported by the National Supercomputer Center in Tianjin.
文摘Subduction zones are major convergent boundaries,where the downgoing oceanic plates usually form continuous tabular slabs extending deep into the Earth’s interior.However,many subducting slabs especially those with young ages,exhibit complex geometry,with varying degrees of influence on the overlying continent and surface environment.To better understand the mechanism of such slab deformation,we apply four-dimensional finite element geodynamic models with data assimilation to investigate the evolution of the Cocos subduction in Central America,where a double-slab configuration with complex tearing has recently been observed.We reproduce the subduction history of the Cocos slab since the Eocene.During this period,multiple episodes of tearing occurred within the Cocos slab,starting at 25 Ma.We find that the ancient Farallon slab,subducted during the Mesozoic,enhances the lateral pressure gradient across the slab hinge,promoting eastward mantle flow and tearing of the Cocos slab.The repeated tearing and subduction of the young Cocos plate have shaped the complex slab configuration in the region.
基金partially supported by the Comisión Nacional de Energía Atómica,CNEA(Controlled Nuclear Fusion Program),CONICET(No.11220200101929CO)Universidad Nacional de Cuyo(No.06-C565).
文摘A rotating neoclassical tearing mode(NTM)can increase the trapped ion losses when the frequency of the NTM is close to the precessional frequency of the trapped particles.When an equilibrium electric field,produced by the rotation of the plasma and the density gradient,is present,the average precessional frequency of the trapped ions changes and so does the mode frequency corresponding to the maximum loss rate.Our results show that when an electric field with a value of 11.2 kV/m at q=2 is included the maximum of the trapped ion losses increases from 27% to 30% based on EAST equilibrium.
基金funded by the National Key R&D Program of China(2022YFF0800601)National Natural Science Foundation of China(42174069,U1939204).
文摘The Main Himalayan Thrust(MHT),where the 2015 MW7.8 Gorkha earthquake occurred,features the most seismicity of any structure in Nepal.The structural complexity of the MHT makes it difficult to obtain a definitive interpretation of deep seismogenic structures.The application of new methods and data in this region is necessary to enhance local seismic hazard analyses.In this study,we used a well-designed machine learning-based earthquake location workflow(LOC-FLOW),which incorporates machine learning phase picking,phase association,absolute location,and double-difference relative location,to process seismic data collected by the Hi-CLIMB and NAMASTE seismic networks.We built a high-precision earthquake catalog of both the quiet-period and aftershock seismicity in this region.The seismicity distribution suggests that the quietperiod seismicity(388 events)was controlled by a mid-crustal ramp and the aftershock seismicity(12,669 events)was controlled by several geological structures of the MHT.The higher-level detail of the catalogs derived from this machine learning method reveal clearer structural characteristics,showing how the flat-ramp geometry and a possible duplex structure affect the depth distribution of the seismic events,and how a tear fault changes this distribution along strike.
文摘In the author list,the corresponding author indicator(*)was inadvertently omitted from HOU Zengqian’s name.This has now been corrected to:“HOU Zengqian¹,*”.The online version of this article was corrected.
文摘Unintended dural tear(DT)is not an infrequent complication of biportal percutaneous endoscopic spinal surgery(BESS).DT manifests in neurological deficits,including seizure,headache,and intracranial hemorrhage.Meanwhile,DT may be a risk of emergence agitation(EA)after BESS,which has not yet been reported.We presented a case of a 55-year-old man with L5-S1 intervertebral disc herniation receiving BESS under general anesthesia.A DT about 3-4 mm occurred during the operation,and was repaired immediately.The patient presented EA shouting for a headache after the surgery in post anesthesia care unit(PACU).Sedative agents(midazolam,propofol and dexmedetomidine)were used,only continuously infusion of dexmedetomidine for about 4 h successfully improved EA in PACU.He had no neurologic deficits in following 3 months.This case report highlights the risk of EA when a DT occurs during BESS.Adequate sedation in early phase is critical to resolve the mass effect caused by EA.
基金support from Basic Research Projects of Higher Education Institutions of Liaoning Province(Key Research Projects)(No.JYTZD2023108)General Project of Liaoning Provincial Department of Education(Nos.LJKMZ20220462 and JYTMS20231199).
文摘In order to solve the issues concerning high hot tearing susceptibility(HTS)of Mg-Al-Ca series alloys,a rotating magnetic field(RMF)was applied during their solidification.The effect of RMF at different excitation current intensities(50 A,100 A,and 150 A)on the solidification and hot tearing behavior of AXJ530(Mg-5Al-3Ca-0.17Sr)alloy was investigated.The results indicated that the HTS of AXJ530 alloy decreased with the increase of excitation current intensity.This aspect can be attributed to significant grain refinement under the action of RMF,which improved the intergranular bonding and relieved the stress concentration.On the other hand,the stirring effect of the electromagnetic force on the melt could break up the developed dendrites and delay the dendrite coherence,as well as optimize the feeding channels and improve the feeding drive of the residual liquid at the end of solidification.Therefore,under the action of RMF,the hot tearing initiation of the alloy was suppressed and the feeding efficiency of the liquid was greatly improved,which led to a noticeable reduction of the HTS of the alloy.Moreover,no significant hot tearing was detected in castings at the excitation current parameters of 150 A and 10 Hz.
基金supported by the National Magnetic Confinement Fusion Energy R&D Program of China (Nos.2019YFE03030004 and 2022YFE03100001)。
文摘Tearing modes may play an important role in the density limit disruption.The Magnetohydrodynamic(MHD)code CLT with impurity modules is used to study the tearing mode excited and driven by impurity radiation.The impurity radiation can lead to plasma contraction and local enhancement of the current density.When the locally enhanced region of the current density approaches to the resonance surface,the tearing mode can be excited,even if the tearing mode is stable in the initial equilibrium.Through a scan of the initial atomic number(Z)and impurity concentrations,it is found that impurities with different Z values exhibit similar behaviors in the radiation-driven tearing mode.The impurity radiation can drive tearing mode growth through temperature cooling near the resonance surface,and there exists a linear relationship between the temperature perturbation caused by impurity radiation and the linear growth rate of the tearing mode.Additionally,the impurity can promote the growth of magnetic islands through the radiation cooling inside the magnetic island,and there exists a correlation between the initial parameters of impurity and the width of the saturated magnetic island.
基金financially supported by the National Natural Science Foundation of China(Nos.51871148,51821001)。
文摘The influence of pouring temperature and mold temperature on the fluidity and hot tearing behavior of Al-2Li-2Cu-0.5Mg-0.15Sc-0.1Zr-0.1Ti alloys was investigated by experimental investigation and simulation assessment.The results showed that the length of the spiral fluidity sample increases from 302 to 756 mm as the pouring temperature increases from 680 to 740℃,and from 293 to 736 mm as the mold temperature increases from 200 to 400℃.The hot tearing susceptibility(HTS)firstly decreases and then increases with increasing pouring and mold temperatures,which is mainly caused by the oxide inclusion originating from the high activity of Li at excessive pouring temperature.Excessive pouring and mold temperatures easily produce oxide inclusions and holes,leading to a reduction in fluidity and an increase in HTS of the alloy.Combining the experimental and simulation results,the optimized pouring and mold temperatures are~720℃ and~300℃ for the cast Al-Li alloy,respectively.
文摘This systematic review and meta-analysis evaluated the impact of a restrictive episiotomy protocol on the incidence of severe perineal tears in first vaginal deliveries. A comprehensive search was conducted in Pub Med, CENTRAL, Embase, Latin American and Caribbean Health Sciences Literature and Clinical Trials. gov until June 2024. The study followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was registered in PROSPERO(CRD42024550295). Randomised controlled trials comparing restrictive episiotomy(for foetal indications only) with selective episiotomy in first-time vaginal deliveries were included. Two reviewers independently extracted data, assessed bias using the Cochrane Risk of Bias tool and conducted assessment according to Grading of Recommendations Assessment, Development and Evaluation(GRADE). Statistical analyses were performed using R(v.4.4.0) and Rev Man(v.8.6.1). Two trials with a total of 785 participants met the inclusion criteria. The restrictive episiotomy group showed a 51.8% reduction in severe perineal tears(risk ratio(RR)=0.50, 95% CI 0.21 to 1.21), though this result was not statistically significant. Episiotomy rates were lower in the restrictive group(RR=0.61, 95% CI 0.49 to 0.76). There were no significant differences in minor perineal tears, intact perineum rates or neonatal outcomes between the two groups. Despite the lack of statistical significance in the reduction of severe perineal tear occurrence, the findings suggest a trend towards improved perineal outcomes with restrictive episiotomy. Additionally, given the potential physical and psychological consequences of episiotomies, limiting their use to foetal indications may be beneficial. Further research is needed to confirm these findings and guide clinical practice.
基金Supported by Topcon Corporation and Santen Pharmaceutical Co.Ltd.
文摘AIM:To evaluate parameters measured using the tear film imager(TFI)prototype,a new technology that enables to quantify the tear film thickness of lipid and mucoaqueous layers.METHODS:In this cross-sectional study,patients with dry eye,meibomian gland dysfunction(MGD),and non-dry eye/MGD from February 2020 to January 2021 were analyzed.Quantified TFI outputs included lipid layer thickness(LLT),mucoaqueous layer thickness(MALT),MALT rate of change(MALTR),and lipid breakup time.Two other interferometry devices,LipiView2 and DR-1α,were used for comparison.TFI outputs and other clinical parameters were analyzed using correlation coefficients.Each patient underwent one or several study visits.Baseline values of three device outputs,other clinical parameters,and their changes were examined.RESULTS:This study involved 28 patients(8 patients with dry eyes,13 with MGD,and 7 with non-dry eye/MGD).Baseline TFI,LipiView2,and DR-1αvalues were associated with various clinical parameters.The LLT values estimated using TFI had a correlation with the plugging score in the upper eyelid(r=−0.42).Several TFI values have correlated better than LipiView2 and DR-1α,particularly with questionnaire scores.MALTR by TFI revealed a correlation between standardized patient evaluation on eye dryness(SPEED)and dry eye-related quality of life score(DEQS)scores(r=0.59,0.43),respectively.CONCLUSION:TFI enabled to quantify the LLT and MALT separately over time and shows the moderate correlations between TFI measurements and clinical parameters,which yields the potential for TFI to serve as a complementary tool for assessing dry eye and MGD.
基金supported by the National Natural Science Foundation of China(no. 82320108004)the Construction Engineering Special Fund of “Taishan Scholars” of Shandong Province (ts20190975)the National Clinical Key Specialty(Periodontology) Construction Project。
文摘Cemental tear is a rare and indetectable condition unless obvious clinical signs present with the involvement of surrounding periodontal and periapical tissues. Due to its clinical manifestations similar to common dental issues, such as vertical root fracture,primary endodontic diseases, and periodontal diseases, as well as the low awareness of cemental tear for clinicians, misdiagnosis often occurs. The critical principle for cemental tear treatment is to remove torn fragments, and overlooking fragments leads to futile therapy, which could deteriorate the conditions of the affected teeth. Therefore, accurate diagnosis and subsequent appropriate interventions are vital for managing cemental tear. Novel diagnostic tools, including cone-beam computed tomography(CBCT), microscopes, and enamel matrix derivatives, have improved early detection and management, enhancing tooth retention. The implementation of standardized diagnostic criteria and treatment protocols, combined with improved clinical awareness among dental professionals, serves to mitigate risks of diagnostic errors and suboptimal therapeutic interventions. This expert consensus reviewed the epidemiology, pathogenesis, potential predisposing factors, clinical manifestations, diagnosis,differential diagnosis, treatment, and prognosis of cemental tear, aiming to provide a clinical guideline and facilitate clinicians to have a better understanding of cemental tear.
基金the National Natural Science Foundation of China(Project 51531002,51474043)the Ministry of Science&Technology of China(2013DFA71070)+1 种基金the Ministry of Education of China(SRFDR 20130191110018)Chongqing Municipal Government(CSTC2013JCYJC60001,CEC project,Two River Scholar Project and The Chief Scientist Studio Project).
文摘Hot tearing is often a major casting defect in magnesium alloys and has a significant impact on the quality of their casting products.Hot tearing of magnesium alloys is a complex solidification phenomenon which is still not fully understood,it is of great importance to investigate the hot tearing behaviour of magnesium alloys.This review attempts to summarize the investigations on hot tearing of magnesium alloys over the past decades.The hot tearing criteria including recently developed Kou’s criterion are summarized and compared.The numeric simulation and assessing methods of hot tearing,factors influencing hot tearing,and hot tearing susceptibility(HTS)of magnesium alloys are discussed.
文摘BACKGROUND Arthroscopic procedures are commonly performed for rotator cuff pathology.Repair of rotator cuff tears is a commonly performed procedure.The intraoperative evaluation of the tear size and pattern contributes to the choice and completion of the technique and the prognosis of the repair.AIM To compare the arthroscopic and open measurements with the real dimensions of three different patterns of simulated rotator cuff tears of known size using a plastic shoulder model.METHODS We created three sizes and patterns of simulated supraspinatus tears on a plastic shoulder model(small and large U-shaped,oval-shaped).Six orthopaedic surgeons with three levels of experience measured the dimensions of the tears arthroscopically,using a 5 mm probe,repeating the procedure three times,and then using a ruler(open technique).Arthroscopic,open and computerized measurements were compared.RESULTS A constant underestimation of specific dimensions of the tears was found when measured with an arthroscope,compared to both the open and computerized measurements(mean differences up to-7.5±5.8 mm,P<0.001).No differences were observed between the open and computerized measurements(mean difference-0.4±1.6 mm).The accuracy of arthroscopic and open measurements was 90.5%and 98.5%,respectively.When comparing between levels of experience,senior residents reported smaller tear dimensions when compared both to staff surgeons and fellows.CONCLUSION This study suggests that arthroscopic measurements of full-thickness rotator cuff tears constantly underestimate the dimensions of the tears.Development of more precise arthroscopic techniques or tools for the evaluation of the size and type of rotator cuff tears are necessary.
基金Project (2009AA033501) supported by the High-tech Research and Development Program of China
文摘Pouring and mold temperatures are two important parameters during casting magnesium components. The present study examined their influence on hot tearing susceptibility （HTS） of commercial AZ91D and newly developed Mg-3Nd-0.2Zn-Zr （mass fraction, %; NZ30K） magnesium alloys in gravity permanent mold casting condition. The results indicate that mold temperature shows much more significant influence on the HTS of both alloys than pouring temperature whose influence only can be distinguished at low mold temperature （341 K for AZ91D alloy and 423 K for NZ30K alloy）. Hot tearing susceptibility prediction model concerning feeding parameters, grain size and solidification range, is more suitable to estimate the HTS of different magnesium alloys than the model only concerning feeding parameters. In order to achieve better hot tearing resistance, the ranges of pouring and mold temperatures are suggested to be 961-991 K and≥641 K for AZ91D alloy, 1003-1033 K and≥623 K for NZ30K alloy, respectively.
基金Project(2010CB631200)supported by the National Basic Research Program of China
文摘The solidification characteristics and the hot tearing susceptibility were investigated on two Ni-based superalloys for turbocharger turbine wheel, K418 and K419. The segregation behaviors of the alloying elements and the precipitation phases were also studied. The results show that the solidification behavior of K419 alloy is complicated when compared with K418 due to the interdendritic segregation of many kinds of strong interdendritic partitioning elements in the remaining liquid at the final stage of solidification. The segregation of multiple elements in interdendritic liquid results in an extremely low solidus in K419. A long residual liquid stage is found during the solidification of K419, giving rise to reduced cohesion strength of dendrites and increased sensitivity to hot tearing. A hot tearing susceptibility coefficient（HTS） criterion is proposed based on a hot tearing sensitive model. The HTS value of K419 alloy is larger than that of K418 alloy.
基金Project(2011ZX04001-031)supported by National Science and Technology Major Project of"High-end CNC Machine Tools and Basic Manufacturing Equipment",ChinaProject(51371109)supported by the National Natural Science Foundation of China
文摘The instrumented applied rod casting apparatus （ARCA） was developed to investigate the effects of tensile forces in the hot tearing formation of cast AI-Si alloys. The obtained data of tensile forces/temperature was used to identify hot tearing initiation and propagation and the fracture surface of samples was also investigated. The result shows that the applied tensile forces have a complex effect on load onset for the hot tearing initiation and propagation. During the casting solidification, the tensile forces are gradually increased with the increase of solid fraction. Under the action of tensile forces, there will appear hot tearing and crack propagation on the surface of the sample. When the tensile forces exceed the inherent strength of alloys, there will be fractures on the sample. As for the A356 alloy, the critical fracture stress is about 0.1 MPa. The hot tearing surface morphology shows that the remaining intergranular bridge and liquid films are thick enough to allow the formation of dendrite-tip bumps on the fracture surface.
