AIM: To evaluate anatomical and visual outcomes of episcleral macular buckling (EMB) for posterior retinal detachment in silicone oil filled eyes associated with myopic macular hole.METHODS: Five cases of EMB for init...AIM: To evaluate anatomical and visual outcomes of episcleral macular buckling (EMB) for posterior retinal detachment in silicone oil filled eyes associated with myopic macular hole.METHODS: Five cases of EMB for initial failure of retinal reattachment after internal limiting membrane (ILM) peeling and silicone oil tamponade caused by myopic macular hole were retrospectively reviewed. A silicone sponge sutured directly across the macular region was performed on the silicone oil filled eyes. Silicone oil was removed no sooner than 1 month post- EMB. The duration of follow -up time after removal of silicone oil was more than 3 months.RESULTS: Retinas of five eyes were all reattached at the last follow-up. The postoperative vision ranged from counting fingers to 0.08.CONCLUSION: Anatomical results improved after EBM for posterior retinal detachment in silicone oil filled eyes associated with myopic macular hole, which was not evident for visual outcome.展开更多
The aim of the present study was to evaluate the efficacy and safety of the treatment of myopic foveoschisis patients using the macular buckling with L-shaped titanium plate and silicon sponge combined with vitrectomy...The aim of the present study was to evaluate the efficacy and safety of the treatment of myopic foveoschisis patients using the macular buckling with L-shaped titanium plate and silicon sponge combined with vitrectomy. The data of the patients who underwent macular buckling combined with vitrectomy was collected. The study recorded the following parameters：best corrected visual acuity（BCVA）, axial length, intraocular pressure, central macular thickness, and the position of the titanium plate. Following the surgery, the BCVA of the included patients were improved, whereas the axial lengths were reduced followed by resolution of the foveoschisis compared with that noted prior to the operations. All patients had orbital CT examination and the results indicated that the titanium plates were appropriately placed and were not in contact with the optic nerve. Therefore, it is effective to treat myopic foveaschisis by macular buckling using the L-shaped titanium plate and silicon sponge in the presence of vitrectomy.展开更多
Existing evidence suggests residential greenness is beneficial to human,while no research to date explored the associations of greenness with age-related macular degeneration(AMD).To evaluate the association of greenn...Existing evidence suggests residential greenness is beneficial to human,while no research to date explored the associations of greenness with age-related macular degeneration(AMD).To evaluate the association of greenness with AMD,modification and mediation effect of air pollution,we conducted this prospective study.We con-structed weighted quantile sum(WQS)index as co-exposure to nitrogen oxides(NO_(x)),particulate matter<2.5μm(PM_(2.5)),particulate matter<10μm(PM10).Stratified Cox regression models were applied to test the effect of exposure.Effect modification of air pollution was assessed.Stratified Cox models through the indirect method and Aalen additive risk models were used in mediation analysis.Over median follow-up of 11.67 years,4596 AMD events were ascertained.Hazard ratios(HRs)and 95%confidence intervals(95%CIs)of incident AMD for pollution per interquartile range(IQR)increment were 1.10(1.04–1.16)for nitrogen dioxide(NO_(2)),1.09(1.03–1.15)for NO_(x),1.14(1.05–1.24)for PM_(2.5),1.13(1.05–1.21)for PM10.The HR(95%CI)of AMD associated with greenness 1000 m buffer per IQR increment was 0.91(0.86–0.97),300 m buffer was 0.94(0.89–0.99).The as-sociation between greenness 1000 m and AMD was 28.59%,44.77%,35.59%,32.31%and 27.08%mediated by the decreased WQS index,NO_(2),NO_(x),PM_(2.5) and PM10,respectively.Increased greenness was associated with lower AMD incidence,and air pollution partly mediate it,which implies that interventions aimed at improving air quality and increasing greenness could have a dual benefit in mitigating AMD risk.展开更多
Dear Editor,Diabetic macular edema(DME)is a major cause of visual loss in diabetic patients,which is mainly caused by disruption of the blood-retinal barrier and loss of pericytes and endothelial cells,resulting in th...Dear Editor,Diabetic macular edema(DME)is a major cause of visual loss in diabetic patients,which is mainly caused by disruption of the blood-retinal barrier and loss of pericytes and endothelial cells,resulting in the leakage of plasma and lipids[1].Nowadays,laser photocoagulation,intravitreal injections of anti-vascular endothelial growth factor(anti-VEGF)drugs and dexamethasone implant.展开更多
Dear Editor,I diopathic macular telangiectasia(MacTel)type 1 is a retinal vascular disease characterized by abnormal dilation of macular capillaries,leading to metamorphopsia,progressive vision loss,and temporal scoto...Dear Editor,I diopathic macular telangiectasia(MacTel)type 1 is a retinal vascular disease characterized by abnormal dilation of macular capillaries,leading to metamorphopsia,progressive vision loss,and temporal scotoma enlargement.Currently,there is no standardized treatment protocol for MacTel type 1[1-2].Treatment outcomes can vary significantly among individuals,highlighting the ongoing need for further exploration of new and more effective treatment options.This paper presents a case of refractory macular edema associated with MacTel type 1,which showed a favorable response to pars plana vitrectomy(PPV)and internal limiting membrane(ILM)peeling.展开更多
Subretinal fibrosis is the end-stage sequelae of neovascular age-related macular degeneration.It causes local damage to photoreceptors,retinal pigment epithelium,and choroidal vessels,which leads to permanent central ...Subretinal fibrosis is the end-stage sequelae of neovascular age-related macular degeneration.It causes local damage to photoreceptors,retinal pigment epithelium,and choroidal vessels,which leads to permanent central vision loss of patients with neovascular age-related macular degeneration.The pathogenesis of subretinal fibrosis is complex,and the underlying mechanisms are largely unknown.Therefore,there are no effective treatment options.A thorough understanding of the pathogenesis of subretinal fibrosis and its related mechanisms is important to elucidate its complications and explore potential treatments.The current article reviews several aspects of subretinal fibrosis,including the current understanding on the relationship between neovascular age-related macular degeneration and subretinal fibrosis;multimodal imaging techniques for subretinal fibrosis;animal models for studying subretinal fibrosis;cellular and non-cellular constituents of subretinal fibrosis;pathophysiological mechanisms involved in subretinal fibrosis,such as aging,infiltration of macrophages,different sources of mesenchymal transition to myofibroblast,and activation of complement system and immune cells;and several key molecules and signaling pathways participating in the pathogenesis of subretinal fibrosis,such as vascular endothelial growth factor,connective tissue growth factor,fibroblast growth factor 2,platelet-derived growth factor and platelet-derived growth factor receptor-β,transforming growth factor-βsignaling pathway,Wnt signaling pathway,and the axis of heat shock protein 70-Toll-like receptors 2/4-interleukin-10.This review will improve the understanding of the pathogenesis of subretinal fibrosis,allow the discovery of molecular targets,and explore potential treatments for the management of subretinal fibrosis.展开更多
This study focused on the buckling characteristics of egg-shaped shells with single crack and double cracks under axial pressure.First,the geometric parameters of the egg-shaped shell were designed,and a numerical mod...This study focused on the buckling characteristics of egg-shaped shells with single crack and double cracks under axial pressure.First,the geometric parameters of the egg-shaped shell were designed,and a numerical model of the egg-shaped shell was established.Then,the initial crack was introduced into the equatorial weld of the egg-shaped shell,and the effects of the crack on the buckling characteristics under different wall thicknesses were explored,as were the effects of the single crack direction,double crack angle and spacing on the buckling characteristics.Finally,crack-free,single crack and double crack egg-shaped shells were fabricated from Q235 steel.The buckling loads and failure modes of the three egg-shaped shells were obtained via axial compression experiments.The numerical critical buckling loads and buckling modes were compared with the experimental results to verify the accuracy of the numerical model.The results of this study are valuable for the design of egg-shaped shells under axial loading.展开更多
AIM:To quantitatively assess central macular thickness(CMT),macular neovascularization(MNV)area,vascular tortuosity(VT),and vascular dispersion(VDisp)in neovascular age-related macular degeneration(nAMD),type 1 and ty...AIM:To quantitatively assess central macular thickness(CMT),macular neovascularization(MNV)area,vascular tortuosity(VT),and vascular dispersion(VDisp)in neovascular age-related macular degeneration(nAMD),type 1 and type 2 MNV,by means of optical coherence tomography(OCT)and OCT angiography(OCTA)techniques.METHODS:In this retrospective and observational case series,patients were classified into type 1 or type 2 MNV groups.A comprehensive panel of OCT and OCTA metrics was evaluated,including CMT,MNV area,VT,and VDisp.All subjects underwent a standardized intravitreal conbercept(IVC)regimen[3+pro re nata(PRN)]with a 12-month follow-up.MNV area was obtained by manual measurements with OCTA software,and VT and VDisp were calculated by automated analysis with Image J software.RESULTS:A total of 101 participants were included,with 51 patients in the type 1 MNV group(mean age 67.32±9.12y)and 50 patients in the type 2 MNV group(mean age 64.74±5.21y).The mean number of IVC injections was 3.98±1.53 for type 1 MNV and 3.73±0.81 for type 2 MNV.Both subtypes exhibited significant improvements in visual acuity,accompanied by marked reductions in CMT and MNV area(P<0.05)at 12mo after treatment.In type 2 MNV,VT significantly decreased(P<0.05),whereas no significant change was observed in VT for type 1 MNV.VDisp did not significantly changed in either sybtypes.Moreover,in type 1 MNV,final best-corrected visual acuity(BCVA)using logMAR correlated positively with both pre-and post-treatment CMT,while in type 2 MNV,a significant positive correlation was found between the number of injections and final CMT.CONCLUSION:This study shows that conbercept treatment significantly improves visual acuity and macular structure in both type 1 and type 2 MNV with reductions in CMT and MNV area.The significant reduction in VT in type 2 MNV suggests its potential as a biomarker for disease activity.The findings imply the quantitative assessment useful for the stratification,prognostication,and personalized management of MNV in nAMD.展开更多
AIM:To assess whether the implantation of a posterior chamber phakic intraocular lens produces changes in optical coherence tomography(OCT)measurements of macular thickness(MT)and two parameters that define the struct...AIM:To assess whether the implantation of a posterior chamber phakic intraocular lens produces changes in optical coherence tomography(OCT)measurements of macular thickness(MT)and two parameters that define the structure of the optic nerve,the peripapillary nerve fiber layer(RNFL)and the Bruch’s membrane opening-minimum rim width(BMO-MRW).METHODS:This nonrandomized prospective pre-post study included 86 eyes of 48 patients(age,20-47y;axial length:23.10-28.95 mm)scheduled for myopia or myopic astigmatism correction with implantation of the implantable collamer lens(ICL).Eyes with glaucoma or any other ocular disease that could alter OCT results were excluded.RNFL,BMO-MRW and MT were measured preoperatively,and at 1 and 6mo after surgery using spectral-domain OCT.Changes between preoperative and postoperative values were evaluated.RESULTS:There was a significant increase in BMOMRW at 1mo(mean change:3.48±15.07μm,P=0.041).No significant changes were found during the rest of followup(1-6mo postop.,P=0.623).There was also a significant increase in RNFL thickness at 1mo af ter surger y(1.45±2.18μm,P<0.001),but with a significant reduction from 1 to 6mo postoperatively(P=0.002).Regarding MT,it increased significantly at 1mo(2.46±3.76μm,P<0.001),with a significant decrease afterwards(P=0.048).Measurements of the three parameters at 6mo were slightly superior to preoperative values(P<0.01).CONCLUSION:Minimal changes are induced in BMOMRW,RNFL and MT after ICL implantation in healthy eyes,confirming the safety of the surgical procedure regarding the structure of the optic nerve head and the macula,and indicating that this phakic intraocular lens seems to have a slight impact on OCT measurements.展开更多
Proliferative diabetic retinopathy(PDR)affects approximately 6%of diabetic patients globally.The overall prevalence of diabetic retinopathy is around 22%.Wet age-related macular degeneration(ARMD),the sight-threatenin...Proliferative diabetic retinopathy(PDR)affects approximately 6%of diabetic patients globally.The overall prevalence of diabetic retinopathy is around 22%.Wet age-related macular degeneration(ARMD),the sight-threatening type of ARMD,affects approximately 1.2%-1.3%of the general population and represents 15%of total ARMD cases.While intravitreal anti-vascular endothelial growth factor injections are still the mainstay therapy,there are a few challenges,such as frequent administration,cost burden,and compliance barriers that prompt the need for exploration into systemic oral alternative drugs like fenofibrate,candesartan,and vorolanib.These oral therapies have the advantage of being noninvasive and systemically accessible with few logistical burdens.This review highlights current evidence supporting the use of oral therapies in PDR and wet ARMD management,along with practical limitations and future prospects.展开更多
This investigation aims to analyze thermal buckling and post-buckling behavior of functionally graded graphene nanoplateletreinforced composite(FG-GPLRC)beams.The beams are classified into two types of ideal and non-i...This investigation aims to analyze thermal buckling and post-buckling behavior of functionally graded graphene nanoplateletreinforced composite(FG-GPLRC)beams.The beams are classified into two types of ideal and non-ideal FG-GPLRC beams in which the ideal beams have smooth profiles of material distributions and another beams have layer-wise distributions of materials.The material profiles of the ideal beams are utilized as the controlling tracks for producing the material distributions of the non-ideal beams via a layer-to-layer integration technique.This technique confirms that the overall weight fraction of the materials is the same for both types of beams.The proposed models can be used to determine the material properties of the beams for further investigation on thermal buckling and post-buckling of the beams.Third-order shear deformation theory is employed to construct the energy equations of the problems,and then they are solved by the implementation of the Jacobi-Ritz method cooperating with the direct iteration procedure and Newton-Raphson technique.From our investigation,it can be disclosed that when non-ideal beams are created using ideal beams parabolic profile,the results differ significantly.However,the differences between the results of ideal and non-ideal beams can be eliminated by adding more layers.展开更多
Age-related macular degeneration is a serious neurodegenerative disease of the retina that significantly impacts vision.Unfortunately,the specific pathogenesis remains unclear,and effective early treatment options are...Age-related macular degeneration is a serious neurodegenerative disease of the retina that significantly impacts vision.Unfortunately,the specific pathogenesis remains unclear,and effective early treatment options are consequently lacking.The microbiome is defined as a large ecosystem of microorganisms living within and coexisting with a host.The intestinal microbiome undergoes dynamic changes owing to age,diet,genetics,and other factors.Such dysregulation of the intestinal flora can disrupt the microecological balance,resulting in immunological and metabolic dysfunction in the host,and affecting the development of many diseases.In recent decades,significant evidence has indicated that the intestinal flora also influences systems outside of the digestive tract,including the brain.Indeed,several studies have demonstrated the critical role of the gut-brain axis in the development of brain neurodegenerative diseases,including Alzheimer’s disease and Parkinson’s disease.Similarly,the role of the“gut-eye axis”has been confirmed to play a role in the pathogenesis of many ocular disorders.Moreover,age-related macular degeneration and many brain neurodegenerative diseases have been shown to share several risk factors and to exhibit comparable etiologies.As such,the intestinal flora may play an important role in age-related macular degeneration.Given the above context,the present review aims to clarify the gut-brain and gut-eye connections,assess the effect of intestinal flora and metabolites on age-related macular degeneration,and identify potential diagnostic markers and therapeutic strategies.Currently,direct research on the role of intestinal flora in age-related macular degeneration is still relatively limited,while studies focusing solely on intestinal flora are insufficient to fully elucidate its functional role in age-related macular degeneration.Organ-on-a-chip technology has shown promise in clarifying the gut-eye interactions,while integrating analysis of the intestinal flora with research on metabolites through metabolomics and other techniques is crucial for understanding their potential mechanisms.展开更多
BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic im...BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic implications and longterm management strategies.Vascular and metabolic factors are being thought to play a role in such autoimmune neuro-inflammatory disorders,apart from the obvious immune mediated damage.With the advent of optical coherence tomography angiography(OCTA),it is easy to pick up on these subclinical macular microvascular and structural changes.AIM To study the macular microvascular and structural changes on OCTA in atypical optic neuritis.METHODS This observational cross-sectional study involved 8 NMOSD and 17 MOGAD patients,diagnosed serologically,as well as 10 healthy controls.Macular vascular density(MVD)and ganglion cell+inner plexiform layer thickness(GCIPL)were studied using OCTA.RESULTS There was a significant reduction in MVD in NMOSD and MOGAD affected as well as unaffected eyes when compared with healthy controls.NMOSD and MOGAD affected eyes had significant GCIPL thinning compared with healthy controls.NMOSD unaffected eyes did not show significant GCIPL thinning compared to healthy controls in contrast to MOGAD unaffected eyes.On comparing NMOSD with MOGAD,there was no significant difference in terms of MVD or GCIPL in the affected or unaffected eyes.CONCLUSION Although significant microvascular and structural changes are present on OCTA between atypical optic neuritis and normal patients,they could not help in differentiating between NMOSD and MOGAD cases.展开更多
AIM:To explore the morphological and functional parameters to evaluate the effectiveness of intravitreal injections of ranibizumab(IVR)in treating macular edema(ME)secondary to retinal vein occlusion(RVO).METHODS:This...AIM:To explore the morphological and functional parameters to evaluate the effectiveness of intravitreal injections of ranibizumab(IVR)in treating macular edema(ME)secondary to retinal vein occlusion(RVO).METHODS:This retrospective study involved 65 RVO patients(65 eyes)who received IVR and were followedup for more than 3mo.ME was categorized into cystoid macular edema(CME),diffuse retinal thickening(DRT),and serous retinal detachment(SRD)according to optical coherence tomography(OCT)images.The comparison of best corrected visual acuity(BCVA;logMAR)and central macular thickness(CMT)among different follow-up points and those among 3 groups were performed by Kruskal-Wallis test.The correlation between BCVA and baseline parameters during treatment was analyzed using Spearman correlation analysis.RESULTS:BCVA tended to improve in all groups,with marked improvement in CME and DRT groups.CMT showed the greatest reduction after 1wk,and remained stable over the following 3mo.DRT patients had the worst BCVA and the highest CMT at baseline,but the differences became smaller after IVR treatment.CMT in SRD group was significantly better than in CME and DRT groups 3mo after IVR.Most patients of CME and SRD groups transitioned to a normal pattern at 3mo follow-up.DRT patients were most likely to transform into the other morphological groups,while SRD patients showed minimal transitions.BCVA at baseline was identified as the most important prognostic indicator in all 3 groups.Additionally,DRT patients with a longer clinical course,higher CMT and central retinal vein occlusion(CRVO)tend to exhibit worse BCVA after treatment.In addition,CRVO patients are more likely to have worse BCVA at 2 and 3mo follow-up compared with branch retinal vein occlusion(BRVO)patients in CME group.SRD patients with higher baseline CMT were prone to experiencing worse BCVA after treatment.CONCLUSION:The effectiveness of IVR is strongly correlated with baseline BCVA in all 3 groups.Baseline parameters including clinical course,CMT,and RVO position are also useful in predicting the BCVA at different time points after treatment.展开更多
Background: Exudative, or “wet” age-related macular degeneration (wAMD), characterized by choroidal neovascularization and consequent accumulation of subretinal fluid, is the leading cause of visual loss in elderly ...Background: Exudative, or “wet” age-related macular degeneration (wAMD), characterized by choroidal neovascularization and consequent accumulation of subretinal fluid, is the leading cause of visual loss in elderly patients in Western countries. Objective: To compare the effectiveness of aflibercept vs. ranibizumab for treatment-naive wAMD patients in the real world. Methods: PubMed, Web of Science and Cochrane Library were searched to compare aflibercept with ranibizumab. 21 studies with a total of 13,004 eyes were selected and assessed in this meta-analysis. Results: Compared to ranibizumab, aflibercept was more effective in improving best-corrected visual acuity (BCVA) at 12 months (WMD: −0.04;95% CI: −0.07 to 0.00;p = 0.04). At 3 months, aflibercept was superior to ranibizumab in reducing central retinal thickness in patients with worse baseline BCVA (WMD: −36.19;95% CI: −71.47 to −0.92;p = 0.04), reducing subfoveal choroidal thickness in patients with better baseline BCVA (WMD: −12.67;95% CI: −21.33 to −4.02;p = 0.004), reducing height of subfoveal pigment epithelial detachment (WMD: −43.88;95% CI: −73.88 to −13.87;p = 0.004) and improving the incidence of “dry macula” occurrence (OR: 2.26;95% CI: 1.33 to 3.82;p = 0.003). Conclusions: Compared with ranibizumab, aflibercept showed better efficacy in improving morphological changes at 3 months and visual acuity at 12 months post treatment initiation in community clinical setting.展开更多
The stiffness properties of variable stiffness(VS) composite plates can be controlled by manipulating the variation in the fiber angle, thereby significantly improving their buckling properties. Nonlinear fiber paths ...The stiffness properties of variable stiffness(VS) composite plates can be controlled by manipulating the variation in the fiber angle, thereby significantly improving their buckling properties. Nonlinear fiber paths have attracted attention in the field of composites due to their large design space. The major challenge in adopting nonlinear fiber paths is obtaining a fiber path function within the design space that is easily computable and efficiently yields the highest buckling load of a VS plate. In this investigation, an innovative nonlinear function was proposed to describe the fiber orientation by integrating a center fiber angle into the conventional linear function. The parameters of the nonlinear function can directly represent the fiber angles at a fixed position. This novel approach has promising potential for improving the optimal efficiency of fiber paths because the linear and nonlinear functions are simplified with two identical path parameters. Furthermore, a multilevel optimization method was developed by combining finite element analysis(FEA) with an adaptive radial basis function(RBF) surrogate model, and it was found that the number of FEA cases could be reduced by iteratively inheriting training points. The integration of this nonlinear function with a surrogate model is a significant advancement in the structural optimization of composites. Subsequently, the optimal linear and nonlinear fiber paths were computed to maximize the buckling load of VS plates. The FEA results show that the computational efficiency was greatly improved by the proposed nonlinear function and optimization method. The buckling resistance could be enhanced by the nonlinear fiber path, and the reinforcement mechanism was the redistribution and reduction of in-plane compressive stress.展开更多
AIM:To evaluate whether fluid-air exchange is an effective treatment for unclosed macular hole(MH)after primary vitrectomy.METHODS:This retrospective study included patients with an unclosed MH within 1–2wk after vit...AIM:To evaluate whether fluid-air exchange is an effective treatment for unclosed macular hole(MH)after primary vitrectomy.METHODS:This retrospective study included patients with an unclosed MH within 1–2wk after vitrectomy.Patients were divided into the vitrectomy,fluid-air exchange,and observation groups according to the secondary treatment.The anatomical outcomes and postoperative visual acuity were recorded.RESULTS:The analysis included 25 eyes in 25 patients(16 females)aged 37–74y(vitrectomy group,n=10;fluid-air exchange group,n=9;observation group,n=6).Closure rate after secondary treatment was 100%in the vitrectomy group,88.9%in the fluid-air exchange group and 33.3%in the observation group.Optical coherence tomography images obtained at the last follow-up revealed that continuity of the external limiting membrane(ELM)was significantly more common(P=0.004)in the fluid-air group(8/9 eyes,88.9%)than in the vitrectomy group(2/10 eyes,20.0%)and that macular morphology was better in the fluid-air group than in the vitrectomy group.No serious complications were observed after secondary treatment.CONCLUSION:Fluid-air exchange is an alternative option to repeat vitrectomy for patients with an unclosed MH after initial vitrectomy with elevated macular edge.展开更多
Armored vehicles,to accomplish missions in complex harsh conditions with high mobility,require the transmission system to achieve high energy density and high reliability.The wet multi-disc clutch becomes the perishab...Armored vehicles,to accomplish missions in complex harsh conditions with high mobility,require the transmission system to achieve high energy density and high reliability.The wet multi-disc clutch becomes the perishable component under heavy load,large speed difference,and frequent engagement.Due to the difficulty of maintenance in battlefield,clutch carrying post-buckling separate plate is common,and the clutch working process is obstructed.Therefore,considering the post-buckling plate,the multi-physics thermodynamic model of a wet multi-disc clutch is established to describe the entire engagement and separation process.The influence of the buckling degree on the stress-strain,uniformity of gaps,torque,and temperature characteristics is investigated by the numerical method and testified by bench tests.The results show that with the increasing buckling degree,the clutch engagement and separation times decrease gradually.For the separation process,the non-uniformity of gaps is increased,and gaps are eventually occupied,leading to the continuous rough contact among friction pairs.Therefore,the drag torque is increased.Squeezed by the post-buckling plate,the cooling rates of separate plates are decreased.During repeated engagement-separation,temperatures of plates may reach balance points.Since continuous sliding and temperature concentration,the wear form and degree changes,especially at outer radius.Extra drag torque,heat,and wear threats the friction components which increases the risk of failures of the transmission system and affects the mobility of armored vehicles.展开更多
AIM:To investigate the impact of renal dysfunction on clinical response to intravitreal conbercept injection(IVC)for diabetic macular edema(DME).METHODS:This retrospective study included a total of 100 eyes from 100 p...AIM:To investigate the impact of renal dysfunction on clinical response to intravitreal conbercept injection(IVC)for diabetic macular edema(DME).METHODS:This retrospective study included a total of 100 eyes from 100 patients with DME treated with IVC with 3+PRN regimen.Based on the estimated glomerular filtration rate(eGFR),the patients were divided into normal renal function group(n=37),impaired renal function group(n=27),and renal insufficiency group(n=36).The main outcome measures were best-corrected visual acuity(BCVA)and central subfield macular thickness(CST).Clinical parameters included blood urea nitrogen,serum creatinine,serum uric acid,glycosylated hemoglobin(HbA1c),and hemoglobin.RESULTS:The mean follow-up time was 3.9mo.The mean number of IVCs was 2.07±1.22 in the three groups.Mean BCVA improved significantly from 0.81±0.49 logMAR at baseline to 0.72±0.52 logMAR in the three groups at the final visit(P<0.001).Mean CST decreased significantly from 427.85±148.99μm at baseline to 275.31±108.31μm at final visit(P<0.001).Patients in the normal renal function group had higher baseline hemoglobin levels and thinner baseline CST than those in the impaired renal function and insufficiency renal function group(all P<0.001).Patients in the normal renal function group had higher baseline hemoglobin levels and thinner baseline CST than those in the impaired renal function and insufficiency renal function group(all P<0.001).The three groups had no differences in baseline HbA1c levels(P>0.05).Good baseline BCVA(logMAR,P=0.001)and thicker baseline CST(P=0.041)were associated with visual acuity improvement.Higher eGFR(P<0.001),hemoglobin(P=0.032)and thicker baseline CST(P=0.017)were associated with macular edema retrogression in the conbercept-treated diabetic patients,which showed better anatomical response to IVC.CONCLUSION:Our results indicate that the renal dysfunction is the risk factor associated with the efficacy of IVC for DME.展开更多
Steel cylindrical shells are widely used in engineering structures due to their high strength-to-weight ratio,but they are vulnerable to buckling under axial loads.To address this limitation,fiber-reinforced polymer(F...Steel cylindrical shells are widely used in engineering structures due to their high strength-to-weight ratio,but they are vulnerable to buckling under axial loads.To address this limitation,fiber-reinforced polymer(FRP)composites have emerged as promising materials for structural reinforcement.This study investigates the buckling behavior of steel cylindrical shells reinforced with inner and outer layers of polymer composite materials under axial compression.Using analytical and numerical modeling methods,the critical buckling loads for different reinforcement options were evaluated.Two-sided glass fiber reinforced plastic(GFRP)or carbon fiber reinforced plastic(CFRP)coatings,as well as combined coatings with layers of different composites,were considered.GFRP+CFRPIn the calculations,the coatings were treated as homogeneous orthotropic materials with equivalent averaged elastic characteristics.The numerical analysis revealed that CFRP reinforcement achieved the highest increase in buckling load,with improvements ranging from 9.84%to 47.29%,depending on the composite thickness and steel shell thickness.GFRP reinforcement,while beneficial,demonstrated a lower effectiveness,with buckling load increases between 5.89%and 19.30%.The hybrid reinforcement provided an optimal balance,improving buckling resistance by GFRP+CFRP6.94%to 43.95%.Statistical analysis further identified composite type and thickness as the most significant factors affecting buckling performance.The findings suggest that CFRP is the preferred reinforcement material,especially when applied to thin-walled cylindrical shells,while hybrid reinforcements can be effectively utilized for structures requiring a balance between stiffness and ductility.These insights provide a foundation for optimizing FRP reinforcement strategies to enhance the structural integrity of steel shells in engineering applications.展开更多
文摘AIM: To evaluate anatomical and visual outcomes of episcleral macular buckling (EMB) for posterior retinal detachment in silicone oil filled eyes associated with myopic macular hole.METHODS: Five cases of EMB for initial failure of retinal reattachment after internal limiting membrane (ILM) peeling and silicone oil tamponade caused by myopic macular hole were retrospectively reviewed. A silicone sponge sutured directly across the macular region was performed on the silicone oil filled eyes. Silicone oil was removed no sooner than 1 month post- EMB. The duration of follow -up time after removal of silicone oil was more than 3 months.RESULTS: Retinas of five eyes were all reattached at the last follow-up. The postoperative vision ranged from counting fingers to 0.08.CONCLUSION: Anatomical results improved after EBM for posterior retinal detachment in silicone oil filled eyes associated with myopic macular hole, which was not evident for visual outcome.
基金Supported by National Natural Science Foundation of China(No.81000388)Health and Family Planning Commission of Hunan Province(No.132015-016)Natural Science Foundation of Hunan Province(No.12JJ3120)
文摘The aim of the present study was to evaluate the efficacy and safety of the treatment of myopic foveoschisis patients using the macular buckling with L-shaped titanium plate and silicon sponge combined with vitrectomy. The data of the patients who underwent macular buckling combined with vitrectomy was collected. The study recorded the following parameters：best corrected visual acuity（BCVA）, axial length, intraocular pressure, central macular thickness, and the position of the titanium plate. Following the surgery, the BCVA of the included patients were improved, whereas the axial lengths were reduced followed by resolution of the foveoschisis compared with that noted prior to the operations. All patients had orbital CT examination and the results indicated that the titanium plates were appropriately placed and were not in contact with the optic nerve. Therefore, it is effective to treat myopic foveaschisis by macular buckling using the L-shaped titanium plate and silicon sponge in the presence of vitrectomy.
基金supported by the High-level Talents Introduction Plan from Central South University(No.502045003)the National Natural Science Foundation of China(No.42277438)Hunan Provincial Natural Science Foundation for Distinguished Young Scholars(No.2024JJ2082)to Fang Xiao,and the Postgraduate Independent Exploration and Innovation Project of Central South University,China(Nos.2024ZZTS0557 and 2023ZZTS0993)。
文摘Existing evidence suggests residential greenness is beneficial to human,while no research to date explored the associations of greenness with age-related macular degeneration(AMD).To evaluate the association of greenness with AMD,modification and mediation effect of air pollution,we conducted this prospective study.We con-structed weighted quantile sum(WQS)index as co-exposure to nitrogen oxides(NO_(x)),particulate matter<2.5μm(PM_(2.5)),particulate matter<10μm(PM10).Stratified Cox regression models were applied to test the effect of exposure.Effect modification of air pollution was assessed.Stratified Cox models through the indirect method and Aalen additive risk models were used in mediation analysis.Over median follow-up of 11.67 years,4596 AMD events were ascertained.Hazard ratios(HRs)and 95%confidence intervals(95%CIs)of incident AMD for pollution per interquartile range(IQR)increment were 1.10(1.04–1.16)for nitrogen dioxide(NO_(2)),1.09(1.03–1.15)for NO_(x),1.14(1.05–1.24)for PM_(2.5),1.13(1.05–1.21)for PM10.The HR(95%CI)of AMD associated with greenness 1000 m buffer per IQR increment was 0.91(0.86–0.97),300 m buffer was 0.94(0.89–0.99).The as-sociation between greenness 1000 m and AMD was 28.59%,44.77%,35.59%,32.31%and 27.08%mediated by the decreased WQS index,NO_(2),NO_(x),PM_(2.5) and PM10,respectively.Increased greenness was associated with lower AMD incidence,and air pollution partly mediate it,which implies that interventions aimed at improving air quality and increasing greenness could have a dual benefit in mitigating AMD risk.
基金Supported by National Natural Science Foundation of China(No.82171062No.82301222)Zhejiang Provincial Natural Science Foundation of China(No.LY20H120002).
文摘Dear Editor,Diabetic macular edema(DME)is a major cause of visual loss in diabetic patients,which is mainly caused by disruption of the blood-retinal barrier and loss of pericytes and endothelial cells,resulting in the leakage of plasma and lipids[1].Nowadays,laser photocoagulation,intravitreal injections of anti-vascular endothelial growth factor(anti-VEGF)drugs and dexamethasone implant.
基金Supported by Science and Technology Project of Sichuan Provincial Health Commission(No.24WXXT13)North Sichuan Medical College Doctor Start-up Fund Project(No.CBY24-QDA01).
文摘Dear Editor,I diopathic macular telangiectasia(MacTel)type 1 is a retinal vascular disease characterized by abnormal dilation of macular capillaries,leading to metamorphopsia,progressive vision loss,and temporal scotoma enlargement.Currently,there is no standardized treatment protocol for MacTel type 1[1-2].Treatment outcomes can vary significantly among individuals,highlighting the ongoing need for further exploration of new and more effective treatment options.This paper presents a case of refractory macular edema associated with MacTel type 1,which showed a favorable response to pars plana vitrectomy(PPV)and internal limiting membrane(ILM)peeling.
基金supported by grants from National Key R&D Program of China,No.2023YFC2506100(to JZ)the National Natural Science Foundation of China,No.82171062(to JZ).
文摘Subretinal fibrosis is the end-stage sequelae of neovascular age-related macular degeneration.It causes local damage to photoreceptors,retinal pigment epithelium,and choroidal vessels,which leads to permanent central vision loss of patients with neovascular age-related macular degeneration.The pathogenesis of subretinal fibrosis is complex,and the underlying mechanisms are largely unknown.Therefore,there are no effective treatment options.A thorough understanding of the pathogenesis of subretinal fibrosis and its related mechanisms is important to elucidate its complications and explore potential treatments.The current article reviews several aspects of subretinal fibrosis,including the current understanding on the relationship between neovascular age-related macular degeneration and subretinal fibrosis;multimodal imaging techniques for subretinal fibrosis;animal models for studying subretinal fibrosis;cellular and non-cellular constituents of subretinal fibrosis;pathophysiological mechanisms involved in subretinal fibrosis,such as aging,infiltration of macrophages,different sources of mesenchymal transition to myofibroblast,and activation of complement system and immune cells;and several key molecules and signaling pathways participating in the pathogenesis of subretinal fibrosis,such as vascular endothelial growth factor,connective tissue growth factor,fibroblast growth factor 2,platelet-derived growth factor and platelet-derived growth factor receptor-β,transforming growth factor-βsignaling pathway,Wnt signaling pathway,and the axis of heat shock protein 70-Toll-like receptors 2/4-interleukin-10.This review will improve the understanding of the pathogenesis of subretinal fibrosis,allow the discovery of molecular targets,and explore potential treatments for the management of subretinal fibrosis.
基金supported by the National Natural Science Foundation of China(Grant No.52271277)the Natural Science Foundation of Jiangsu Province(Grant No.BK20211343)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.SJCX23_2150).
文摘This study focused on the buckling characteristics of egg-shaped shells with single crack and double cracks under axial pressure.First,the geometric parameters of the egg-shaped shell were designed,and a numerical model of the egg-shaped shell was established.Then,the initial crack was introduced into the equatorial weld of the egg-shaped shell,and the effects of the crack on the buckling characteristics under different wall thicknesses were explored,as were the effects of the single crack direction,double crack angle and spacing on the buckling characteristics.Finally,crack-free,single crack and double crack egg-shaped shells were fabricated from Q235 steel.The buckling loads and failure modes of the three egg-shaped shells were obtained via axial compression experiments.The numerical critical buckling loads and buckling modes were compared with the experimental results to verify the accuracy of the numerical model.The results of this study are valuable for the design of egg-shaped shells under axial loading.
基金Supported by Natural Science Foundation of Shandong Province(No.ZR2023MH363)Bethune Langmu Young Scholars Research Fund Project(No.BJ-LM2021007J).
文摘AIM:To quantitatively assess central macular thickness(CMT),macular neovascularization(MNV)area,vascular tortuosity(VT),and vascular dispersion(VDisp)in neovascular age-related macular degeneration(nAMD),type 1 and type 2 MNV,by means of optical coherence tomography(OCT)and OCT angiography(OCTA)techniques.METHODS:In this retrospective and observational case series,patients were classified into type 1 or type 2 MNV groups.A comprehensive panel of OCT and OCTA metrics was evaluated,including CMT,MNV area,VT,and VDisp.All subjects underwent a standardized intravitreal conbercept(IVC)regimen[3+pro re nata(PRN)]with a 12-month follow-up.MNV area was obtained by manual measurements with OCTA software,and VT and VDisp were calculated by automated analysis with Image J software.RESULTS:A total of 101 participants were included,with 51 patients in the type 1 MNV group(mean age 67.32±9.12y)and 50 patients in the type 2 MNV group(mean age 64.74±5.21y).The mean number of IVC injections was 3.98±1.53 for type 1 MNV and 3.73±0.81 for type 2 MNV.Both subtypes exhibited significant improvements in visual acuity,accompanied by marked reductions in CMT and MNV area(P<0.05)at 12mo after treatment.In type 2 MNV,VT significantly decreased(P<0.05),whereas no significant change was observed in VT for type 1 MNV.VDisp did not significantly changed in either sybtypes.Moreover,in type 1 MNV,final best-corrected visual acuity(BCVA)using logMAR correlated positively with both pre-and post-treatment CMT,while in type 2 MNV,a significant positive correlation was found between the number of injections and final CMT.CONCLUSION:This study shows that conbercept treatment significantly improves visual acuity and macular structure in both type 1 and type 2 MNV with reductions in CMT and MNV area.The significant reduction in VT in type 2 MNV suggests its potential as a biomarker for disease activity.The findings imply the quantitative assessment useful for the stratification,prognostication,and personalized management of MNV in nAMD.
文摘AIM:To assess whether the implantation of a posterior chamber phakic intraocular lens produces changes in optical coherence tomography(OCT)measurements of macular thickness(MT)and two parameters that define the structure of the optic nerve,the peripapillary nerve fiber layer(RNFL)and the Bruch’s membrane opening-minimum rim width(BMO-MRW).METHODS:This nonrandomized prospective pre-post study included 86 eyes of 48 patients(age,20-47y;axial length:23.10-28.95 mm)scheduled for myopia or myopic astigmatism correction with implantation of the implantable collamer lens(ICL).Eyes with glaucoma or any other ocular disease that could alter OCT results were excluded.RNFL,BMO-MRW and MT were measured preoperatively,and at 1 and 6mo after surgery using spectral-domain OCT.Changes between preoperative and postoperative values were evaluated.RESULTS:There was a significant increase in BMOMRW at 1mo(mean change:3.48±15.07μm,P=0.041).No significant changes were found during the rest of followup(1-6mo postop.,P=0.623).There was also a significant increase in RNFL thickness at 1mo af ter surger y(1.45±2.18μm,P<0.001),but with a significant reduction from 1 to 6mo postoperatively(P=0.002).Regarding MT,it increased significantly at 1mo(2.46±3.76μm,P<0.001),with a significant decrease afterwards(P=0.048).Measurements of the three parameters at 6mo were slightly superior to preoperative values(P<0.01).CONCLUSION:Minimal changes are induced in BMOMRW,RNFL and MT after ICL implantation in healthy eyes,confirming the safety of the surgical procedure regarding the structure of the optic nerve head and the macula,and indicating that this phakic intraocular lens seems to have a slight impact on OCT measurements.
文摘Proliferative diabetic retinopathy(PDR)affects approximately 6%of diabetic patients globally.The overall prevalence of diabetic retinopathy is around 22%.Wet age-related macular degeneration(ARMD),the sight-threatening type of ARMD,affects approximately 1.2%-1.3%of the general population and represents 15%of total ARMD cases.While intravitreal anti-vascular endothelial growth factor injections are still the mainstay therapy,there are a few challenges,such as frequent administration,cost burden,and compliance barriers that prompt the need for exploration into systemic oral alternative drugs like fenofibrate,candesartan,and vorolanib.These oral therapies have the advantage of being noninvasive and systemically accessible with few logistical burdens.This review highlights current evidence supporting the use of oral therapies in PDR and wet ARMD management,along with practical limitations and future prospects.
基金supported by the Thailand Science Research and Innovation Fund(Grant No.FRB660041/0227).
文摘This investigation aims to analyze thermal buckling and post-buckling behavior of functionally graded graphene nanoplateletreinforced composite(FG-GPLRC)beams.The beams are classified into two types of ideal and non-ideal FG-GPLRC beams in which the ideal beams have smooth profiles of material distributions and another beams have layer-wise distributions of materials.The material profiles of the ideal beams are utilized as the controlling tracks for producing the material distributions of the non-ideal beams via a layer-to-layer integration technique.This technique confirms that the overall weight fraction of the materials is the same for both types of beams.The proposed models can be used to determine the material properties of the beams for further investigation on thermal buckling and post-buckling of the beams.Third-order shear deformation theory is employed to construct the energy equations of the problems,and then they are solved by the implementation of the Jacobi-Ritz method cooperating with the direct iteration procedure and Newton-Raphson technique.From our investigation,it can be disclosed that when non-ideal beams are created using ideal beams parabolic profile,the results differ significantly.However,the differences between the results of ideal and non-ideal beams can be eliminated by adding more layers.
基金supported by the National Natural Science Foundation of China,No.82171080Nanjing Medical Science and Technology Development Project,No.YKK23264Postgraduate Research&Practice Innovation Program of Jiangsu Province,Nos.JX10414151,JX10414152(all to KL)。
文摘Age-related macular degeneration is a serious neurodegenerative disease of the retina that significantly impacts vision.Unfortunately,the specific pathogenesis remains unclear,and effective early treatment options are consequently lacking.The microbiome is defined as a large ecosystem of microorganisms living within and coexisting with a host.The intestinal microbiome undergoes dynamic changes owing to age,diet,genetics,and other factors.Such dysregulation of the intestinal flora can disrupt the microecological balance,resulting in immunological and metabolic dysfunction in the host,and affecting the development of many diseases.In recent decades,significant evidence has indicated that the intestinal flora also influences systems outside of the digestive tract,including the brain.Indeed,several studies have demonstrated the critical role of the gut-brain axis in the development of brain neurodegenerative diseases,including Alzheimer’s disease and Parkinson’s disease.Similarly,the role of the“gut-eye axis”has been confirmed to play a role in the pathogenesis of many ocular disorders.Moreover,age-related macular degeneration and many brain neurodegenerative diseases have been shown to share several risk factors and to exhibit comparable etiologies.As such,the intestinal flora may play an important role in age-related macular degeneration.Given the above context,the present review aims to clarify the gut-brain and gut-eye connections,assess the effect of intestinal flora and metabolites on age-related macular degeneration,and identify potential diagnostic markers and therapeutic strategies.Currently,direct research on the role of intestinal flora in age-related macular degeneration is still relatively limited,while studies focusing solely on intestinal flora are insufficient to fully elucidate its functional role in age-related macular degeneration.Organ-on-a-chip technology has shown promise in clarifying the gut-eye interactions,while integrating analysis of the intestinal flora with research on metabolites through metabolomics and other techniques is crucial for understanding their potential mechanisms.
文摘BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic implications and longterm management strategies.Vascular and metabolic factors are being thought to play a role in such autoimmune neuro-inflammatory disorders,apart from the obvious immune mediated damage.With the advent of optical coherence tomography angiography(OCTA),it is easy to pick up on these subclinical macular microvascular and structural changes.AIM To study the macular microvascular and structural changes on OCTA in atypical optic neuritis.METHODS This observational cross-sectional study involved 8 NMOSD and 17 MOGAD patients,diagnosed serologically,as well as 10 healthy controls.Macular vascular density(MVD)and ganglion cell+inner plexiform layer thickness(GCIPL)were studied using OCTA.RESULTS There was a significant reduction in MVD in NMOSD and MOGAD affected as well as unaffected eyes when compared with healthy controls.NMOSD and MOGAD affected eyes had significant GCIPL thinning compared with healthy controls.NMOSD unaffected eyes did not show significant GCIPL thinning compared to healthy controls in contrast to MOGAD unaffected eyes.On comparing NMOSD with MOGAD,there was no significant difference in terms of MVD or GCIPL in the affected or unaffected eyes.CONCLUSION Although significant microvascular and structural changes are present on OCTA between atypical optic neuritis and normal patients,they could not help in differentiating between NMOSD and MOGAD cases.
基金Supported by the Suzhou Medical Innovation Application Research Project(SZM2023027).
文摘AIM:To explore the morphological and functional parameters to evaluate the effectiveness of intravitreal injections of ranibizumab(IVR)in treating macular edema(ME)secondary to retinal vein occlusion(RVO).METHODS:This retrospective study involved 65 RVO patients(65 eyes)who received IVR and were followedup for more than 3mo.ME was categorized into cystoid macular edema(CME),diffuse retinal thickening(DRT),and serous retinal detachment(SRD)according to optical coherence tomography(OCT)images.The comparison of best corrected visual acuity(BCVA;logMAR)and central macular thickness(CMT)among different follow-up points and those among 3 groups were performed by Kruskal-Wallis test.The correlation between BCVA and baseline parameters during treatment was analyzed using Spearman correlation analysis.RESULTS:BCVA tended to improve in all groups,with marked improvement in CME and DRT groups.CMT showed the greatest reduction after 1wk,and remained stable over the following 3mo.DRT patients had the worst BCVA and the highest CMT at baseline,but the differences became smaller after IVR treatment.CMT in SRD group was significantly better than in CME and DRT groups 3mo after IVR.Most patients of CME and SRD groups transitioned to a normal pattern at 3mo follow-up.DRT patients were most likely to transform into the other morphological groups,while SRD patients showed minimal transitions.BCVA at baseline was identified as the most important prognostic indicator in all 3 groups.Additionally,DRT patients with a longer clinical course,higher CMT and central retinal vein occlusion(CRVO)tend to exhibit worse BCVA after treatment.In addition,CRVO patients are more likely to have worse BCVA at 2 and 3mo follow-up compared with branch retinal vein occlusion(BRVO)patients in CME group.SRD patients with higher baseline CMT were prone to experiencing worse BCVA after treatment.CONCLUSION:The effectiveness of IVR is strongly correlated with baseline BCVA in all 3 groups.Baseline parameters including clinical course,CMT,and RVO position are also useful in predicting the BCVA at different time points after treatment.
文摘Background: Exudative, or “wet” age-related macular degeneration (wAMD), characterized by choroidal neovascularization and consequent accumulation of subretinal fluid, is the leading cause of visual loss in elderly patients in Western countries. Objective: To compare the effectiveness of aflibercept vs. ranibizumab for treatment-naive wAMD patients in the real world. Methods: PubMed, Web of Science and Cochrane Library were searched to compare aflibercept with ranibizumab. 21 studies with a total of 13,004 eyes were selected and assessed in this meta-analysis. Results: Compared to ranibizumab, aflibercept was more effective in improving best-corrected visual acuity (BCVA) at 12 months (WMD: −0.04;95% CI: −0.07 to 0.00;p = 0.04). At 3 months, aflibercept was superior to ranibizumab in reducing central retinal thickness in patients with worse baseline BCVA (WMD: −36.19;95% CI: −71.47 to −0.92;p = 0.04), reducing subfoveal choroidal thickness in patients with better baseline BCVA (WMD: −12.67;95% CI: −21.33 to −4.02;p = 0.004), reducing height of subfoveal pigment epithelial detachment (WMD: −43.88;95% CI: −73.88 to −13.87;p = 0.004) and improving the incidence of “dry macula” occurrence (OR: 2.26;95% CI: 1.33 to 3.82;p = 0.003). Conclusions: Compared with ranibizumab, aflibercept showed better efficacy in improving morphological changes at 3 months and visual acuity at 12 months post treatment initiation in community clinical setting.
基金supported by the National Natural Science Foundation of China (No. 52305026)the China Postdoctoral Science Foundation (No. 2023M741941)。
文摘The stiffness properties of variable stiffness(VS) composite plates can be controlled by manipulating the variation in the fiber angle, thereby significantly improving their buckling properties. Nonlinear fiber paths have attracted attention in the field of composites due to their large design space. The major challenge in adopting nonlinear fiber paths is obtaining a fiber path function within the design space that is easily computable and efficiently yields the highest buckling load of a VS plate. In this investigation, an innovative nonlinear function was proposed to describe the fiber orientation by integrating a center fiber angle into the conventional linear function. The parameters of the nonlinear function can directly represent the fiber angles at a fixed position. This novel approach has promising potential for improving the optimal efficiency of fiber paths because the linear and nonlinear functions are simplified with two identical path parameters. Furthermore, a multilevel optimization method was developed by combining finite element analysis(FEA) with an adaptive radial basis function(RBF) surrogate model, and it was found that the number of FEA cases could be reduced by iteratively inheriting training points. The integration of this nonlinear function with a surrogate model is a significant advancement in the structural optimization of composites. Subsequently, the optimal linear and nonlinear fiber paths were computed to maximize the buckling load of VS plates. The FEA results show that the computational efficiency was greatly improved by the proposed nonlinear function and optimization method. The buckling resistance could be enhanced by the nonlinear fiber path, and the reinforcement mechanism was the redistribution and reduction of in-plane compressive stress.
文摘AIM:To evaluate whether fluid-air exchange is an effective treatment for unclosed macular hole(MH)after primary vitrectomy.METHODS:This retrospective study included patients with an unclosed MH within 1–2wk after vitrectomy.Patients were divided into the vitrectomy,fluid-air exchange,and observation groups according to the secondary treatment.The anatomical outcomes and postoperative visual acuity were recorded.RESULTS:The analysis included 25 eyes in 25 patients(16 females)aged 37–74y(vitrectomy group,n=10;fluid-air exchange group,n=9;observation group,n=6).Closure rate after secondary treatment was 100%in the vitrectomy group,88.9%in the fluid-air exchange group and 33.3%in the observation group.Optical coherence tomography images obtained at the last follow-up revealed that continuity of the external limiting membrane(ELM)was significantly more common(P=0.004)in the fluid-air group(8/9 eyes,88.9%)than in the vitrectomy group(2/10 eyes,20.0%)and that macular morphology was better in the fluid-air group than in the vitrectomy group.No serious complications were observed after secondary treatment.CONCLUSION:Fluid-air exchange is an alternative option to repeat vitrectomy for patients with an unclosed MH after initial vitrectomy with elevated macular edge.
基金supported by the National Natural Science Foundations of China(Grant Nos.52205047,52175037)Frontier Cross Project of Beijing Institute of Technology(Grant No.2024CX11006)。
文摘Armored vehicles,to accomplish missions in complex harsh conditions with high mobility,require the transmission system to achieve high energy density and high reliability.The wet multi-disc clutch becomes the perishable component under heavy load,large speed difference,and frequent engagement.Due to the difficulty of maintenance in battlefield,clutch carrying post-buckling separate plate is common,and the clutch working process is obstructed.Therefore,considering the post-buckling plate,the multi-physics thermodynamic model of a wet multi-disc clutch is established to describe the entire engagement and separation process.The influence of the buckling degree on the stress-strain,uniformity of gaps,torque,and temperature characteristics is investigated by the numerical method and testified by bench tests.The results show that with the increasing buckling degree,the clutch engagement and separation times decrease gradually.For the separation process,the non-uniformity of gaps is increased,and gaps are eventually occupied,leading to the continuous rough contact among friction pairs.Therefore,the drag torque is increased.Squeezed by the post-buckling plate,the cooling rates of separate plates are decreased.During repeated engagement-separation,temperatures of plates may reach balance points.Since continuous sliding and temperature concentration,the wear form and degree changes,especially at outer radius.Extra drag torque,heat,and wear threats the friction components which increases the risk of failures of the transmission system and affects the mobility of armored vehicles.
基金Supported by Basic and Applied Basic Research Project of Guangzhou Science and Technology Plan(No.202201020008,No.2023A03J0584).
文摘AIM:To investigate the impact of renal dysfunction on clinical response to intravitreal conbercept injection(IVC)for diabetic macular edema(DME).METHODS:This retrospective study included a total of 100 eyes from 100 patients with DME treated with IVC with 3+PRN regimen.Based on the estimated glomerular filtration rate(eGFR),the patients were divided into normal renal function group(n=37),impaired renal function group(n=27),and renal insufficiency group(n=36).The main outcome measures were best-corrected visual acuity(BCVA)and central subfield macular thickness(CST).Clinical parameters included blood urea nitrogen,serum creatinine,serum uric acid,glycosylated hemoglobin(HbA1c),and hemoglobin.RESULTS:The mean follow-up time was 3.9mo.The mean number of IVCs was 2.07±1.22 in the three groups.Mean BCVA improved significantly from 0.81±0.49 logMAR at baseline to 0.72±0.52 logMAR in the three groups at the final visit(P<0.001).Mean CST decreased significantly from 427.85±148.99μm at baseline to 275.31±108.31μm at final visit(P<0.001).Patients in the normal renal function group had higher baseline hemoglobin levels and thinner baseline CST than those in the impaired renal function and insufficiency renal function group(all P<0.001).Patients in the normal renal function group had higher baseline hemoglobin levels and thinner baseline CST than those in the impaired renal function and insufficiency renal function group(all P<0.001).The three groups had no differences in baseline HbA1c levels(P>0.05).Good baseline BCVA(logMAR,P=0.001)and thicker baseline CST(P=0.041)were associated with visual acuity improvement.Higher eGFR(P<0.001),hemoglobin(P=0.032)and thicker baseline CST(P=0.017)were associated with macular edema retrogression in the conbercept-treated diabetic patients,which showed better anatomical response to IVC.CONCLUSION:Our results indicate that the renal dysfunction is the risk factor associated with the efficacy of IVC for DME.
文摘Steel cylindrical shells are widely used in engineering structures due to their high strength-to-weight ratio,but they are vulnerable to buckling under axial loads.To address this limitation,fiber-reinforced polymer(FRP)composites have emerged as promising materials for structural reinforcement.This study investigates the buckling behavior of steel cylindrical shells reinforced with inner and outer layers of polymer composite materials under axial compression.Using analytical and numerical modeling methods,the critical buckling loads for different reinforcement options were evaluated.Two-sided glass fiber reinforced plastic(GFRP)or carbon fiber reinforced plastic(CFRP)coatings,as well as combined coatings with layers of different composites,were considered.GFRP+CFRPIn the calculations,the coatings were treated as homogeneous orthotropic materials with equivalent averaged elastic characteristics.The numerical analysis revealed that CFRP reinforcement achieved the highest increase in buckling load,with improvements ranging from 9.84%to 47.29%,depending on the composite thickness and steel shell thickness.GFRP reinforcement,while beneficial,demonstrated a lower effectiveness,with buckling load increases between 5.89%and 19.30%.The hybrid reinforcement provided an optimal balance,improving buckling resistance by GFRP+CFRP6.94%to 43.95%.Statistical analysis further identified composite type and thickness as the most significant factors affecting buckling performance.The findings suggest that CFRP is the preferred reinforcement material,especially when applied to thin-walled cylindrical shells,while hybrid reinforcements can be effectively utilized for structures requiring a balance between stiffness and ductility.These insights provide a foundation for optimizing FRP reinforcement strategies to enhance the structural integrity of steel shells in engineering applications.
