Clinical Efficacy and Safety of Foldable Capsular Vitreous Body Implant Surgery in 22 Cases of Silicone Oil-dependent Eyes

Objective This study aimed to evaluate the clinical efficacy and safety of foldable capsular vitreous body(FCVB)implant surgery in silicone oil-dependent eyes.Methods A total of 22 participants with silicone oil-dependent eyes who received treatment with FCVB implant surgery between January 2019 and June 2020 were included in this retrospective study.The intraocular pressure(IOP),best-corrected visual acuity(BCVA),demographic data,and any recorded complications were evaluated.Results The postoperative IOP(12.73±4.20 mmHg)was significantly improved(P=0.03)compared to the preoperative IOP(10.23±3.69 mmHg)(the main endpoint).There was no significant difference(P=0.33)in the final BCVA preoperation and 3rd month postoperation(the secondary endpoint).The most common postoperative complication was hyphema.Other common postoperative complications included corneal opacity,a shallow anterior chamber,and a low IOP.Conclusion FCVB implant surgery is a safe and effective method for treating silicone oil-dependent eyes;however,attention should be paid to the prevention and timely treatment of complications.

Silicone oil as a corneal lubricant to reduce corneal edema and improve visualization during

AIM:To evaluate the efficacy and safety of silicone oil(SO)as a corneal lubricant to improve visualization during vitrectomy.METHODS:Patients who underwent vitreoretinal surgery were divided into two groups.Group 1 was operated on with initial SO(Oxane 5700)as a corneal lubricant.Group 2 was operated on with initial lactated ringer’s solution(LRS)and then replaced with SO as required.Fundus clarity was scored during the surgery.Fluorescein staining was performed to determine the damage to corneal epithelium.RESULTS:Totally 114 eyes of 114 patients were included.Single SO use maintained a clear cornea and provided excellent visualization of surgical image.In group 1,the fundus clarity was grade 3 in 41/45 eyes and grade 2 in 4/45 eyes.In group 2,corneal edema frequently occurred after initial LRS use.The fundus clarity was grade 3 in 19/69 eyes,2 in 37/69 eyes and 1 in 13/69 eyes(P<0.05).SO was applied in 29 eyes of initial LRS use with subsequent corneal edema,which eliminated the corneal edema in 26 eyes.Corneal fluorescein staining score in group 1 was 0 in 28 eyes,1 in 11 eyes and 2 in 6 eyes,and 40,20 and 9,respectively,in group 2(all P>0.05).CONCLUSION:The use of SO as a corneal lubricant is effective and safe for preserving and improving corneal clarity and providing clear surgical field during vitrectomy.

The Various Complications Associated with Use of Silicone Oil in Rhegmatogenous Retinal Detachment (RRD) Surgery via Three-Port Vitrectomy (3PV): A Retrospective Study at the Ophthalmology Center of Abass Ndao Hospital

Introduction: RRD (Rhegmatogenous Retinal Detachment) is a separation between the neuroepithelium and the pigment epithelium due to the passage of fluid through a retinal dehiscence. It constitutes a major ophthalmologic emergency. Its management is primarily surgical, either through external or internal approaches, with tamponade using gas or silicone oil. The purpose of this study was to report the various complications associated with the use of silicone oil in vitreoretinal surgery. Patients et methods: We conducted a retrospective, descriptive, and analytical study from October 1, 2020, to October 31, 2023, which included all patients who underwent surgery for RRD using three-port vitrectomy (3PV) with tamponade using 1000 centistoke silicone oil (Group 1) and 5000 centistoke silicone oil (Group 2). All patients underwent a complete ophthalmologic examination and were operated on by the same surgeon. Data analysis was performed using Excel software. Results: Overall, 31 patient files representing 33 eyes were collected, with a mean age of 48.83 years and a sex ratio of 4.16. Group 1 consisted of 16 eyes (48.48%), and Group 2 consisted of 17 eyes (51.51%). The different complications observed were cataracts in all phakic subjects, accounting for 57.57%;ocular hypertonia in 69.69% (27.27% in Group 1;42.42% in Group 2);anterior chamber silicone oil migration in 24.24% (9.09% in Group 1;15.15% in Group 2);recurrence of retinal detachment in 21.21% (6.06% in Group 1;15.15% in Group 2);and silicone oil emulsification in 24.24% (15.15% in Group 1;9.09% in Group 2). Additionally, there was one case of corneal degeneration in Group 1. Conclusion: Silicone oil is an effective tamponade agent used in the treatment of retinal detachments. Close patient follow-up is necessary due to the complications associated with its use, which can occur either early or late after surgery.

Non-contact wide-field viewing system-assisted scleral buckling surgery for retinal detachment in silicone oilfilled eyes

AIM:To evaluate scleral buckling(SB)surgery using a noncontact wide-field viewing system and 23-gauge intraocular illumination for the treatment of rhegmatogenous retinal detachment in silicone oil(SO)-filled eyes.METHODS:Totally 9 patients(9 eyes)with retinal detachment in SO-filled eyes were retrospectively analyzed.All patients underwent non-contact wide-field viewing system-assisted buckling surgery with 23-gauge intraocular illumination.SO was removed at an appropriate time based on recovery.The patients were followed up for at least 3mo after SO removal.Retinal reattachment,complications,visual acuity and intraocular pressure(IOP)before and after surgery were observed.RESULTS:Patients were followed up for a mean of 8.22mo(3-22mo)after SO removal.All patients had retinal reattachment.At the final follow-up,visual acuity showed improvement for 8 patients,and no change for 1 patient.The IOP was high in 3 patients before surgery,but it stabilized after treatment;it was not affected in the other patients.None of the patients had infections,hemorrhage,anterior ischemia,or any other complication.CONCLUSION:This new non-contact wide-field viewing system-assisted SB surgery with 23-gauge intraocular illumination is effective and safe for retinal detachment in SO-filled eyes.

Silicone oil migrating into the conjunctival space and orbit after surgery for an eye-penetrating injury:A case report

BACKGROUND We report a case of eye-penetrating injury in which a massive silicone oil migration into the patient’s subconjunctival space and orbit occurred after vitrectomy.CASE SUMMARY A 30-year-old male patient sought medical attention at Ganzhou People’s Hospital after experiencing pain and vision loss in his left eye due to a nail wound on December 9,2023.Diagnosis of penetrating injury caused by magnetic foreign body retention in the left eye and hospitalization for treatment.On December 9,2023,pars plana vitrectomy was performed on the left eye for intraocular foreign body removal,abnormal crystal extraction,retinal photocoagulation.Owing to the discovery of retinal detachment at the posterior pole during surgery,silicone oil was injected to fill the vitreous body,following which upper conjunctival bubble-like swelling was observed.Postoperative orbital computed tomography(CT)review indicated migration of silicone oil to the subconjunctival space and orbit through a self-permeable outlet.On December 18,2023,the patient sought treatment at the First Affiliated Hospital of Nanchang University,China.The patient presented with a pronounced foreign body sensation following left eye surgery.On December 20,2023,the foreign body was removed from the left eye frame and an intraocular examination was conducted.The posterior scleral tear had closed,leading to termination of the surgical procedure following supplementary laser treatment around the tear.The patient reported a significant reduction in ocular surface symptoms just one day after surgery.Furthermore,a notable decrease in the migration of silicone oil was observed in orbital CT scans.CONCLUSION The timing of silicone oil injection for an eye-penetrating injury should be carefully evaluated to avoid the possibility of silicone oil migration.

Endophthalmitis in silicone oil-filled eye: A case report

BACKGROUND Endophthalmitis occurring in silicone oil-filled eyes is a very rare occurrence,with reported incidence rates ranging between 0.07%and 0.039%.Traditional methods of management of infectious endophthalmitis include the removal of silicone oil,washout of the vitreous cavity,administration of intravitreal antibiotics,and reinjection of silicone oil.CASE SUMMARY Herein,we report the case of a 39-year-old man with unilateral endophthalmitis after pars plana vitrectomy and silicone oil tamponade.Intravitreal injections of full-dose antibiotics and anterior chamber washout were used to treat the patient.No signs of retinal toxicity were observed during the follow-up period.CONCLUSION Intravitreal full-dose antibiotic injections and anterior chamber washout are promising alternatives to traditional therapies for endophthalmitis in silicone oilfilled eyes.

Research Progress of Carbon-Silicone Composite Materials

Silicone is a kind of polymer material with high cross-linked structure,which is com-posed by Si-O-Si main chain.Due to the special molecular chain structure,silicone mate-rials are characterized by oxidation resistance,aging resistance,high and low temperature resistance and chemical corrosion resistance.Moreover,silicone materials have process-able properties,simple forming process,good mechanical property,non-toxic and pollution-free.Therefore,silicone has been widely concerned by researchers at home and abroad.In this paper,the main research progress and application directions of carbon-silicone composite at home and abroad in recent years are reviewed.

Endoscopic dacryocystorhinostomy with bicanalicular silicone tube intubation for treating chronic dacryocystitis secondary to nasolacrimal duct stent incarceration

AIM:To investigate the feasibility of endoscopic dacryocystorhinostomy(En-DCR)with bicanalicular silicone tube intubation for treating chronic dacryocystitis secondary to nasolacrimal duct stent(NDS)incarceration.METHODS:En-DCRs were performed on 44 chronic dacryocystitis patients(46 eyes)secondary to NDS incarceration from April 2016 to October 2022.The granuloma and scar tissues were separated,and the removal of NDS incarceration was achieved during the surgery;the flap of the lacrimal sac was trimmed and anastomosed with nasal mucosal,a bicanalicular silicone tube was implanted,and lacrimal size and condition were assessed.The tube was removed 3mo after surgery.During the final follow-up of 12mo when the surgery was completed,the complications and the rates of surgical success were assessed.RESULTS:This study covered 40 patients(42 eyes).Intraoperatively,it was found that the lacrimal sac became small,and the sac wall had granulation and scar tissue attached to the incarcerated NDS in all eyes.At 12mo after surgery completed,the rates of the functional and anatomical success reached 80.95%(34/42)and 83.33%(35/42),respectively.Under the effect of intranasal ostial closure,seven eyes failed to achieve anatomical success.No serious complications(e.g.,visual impairment,sinusitis,and orbital fat prolapse)was observed.CONCLUSION:With the success rate over 80%and no serious complications,En-DCR with bicanalicular silicone tube implantation is effective in treating chronic dacryocystitis secondary to NDS incarceration.

Axial length,vitreoretinal pathology,and anterior chamber depth can predict postoperative refractive outcomes in phacovitrectomy/silicone oil removal

AIM:To evaluate the postoperative refractive prediction error(PE)and determine the factors that af fect the refractive outcomes of combined pars plana vitrectomy(PPV)or silicone oil removal(SOR)with cataract surgery.METHODS:The study is a retrospective,case-series study.Totally 301 eyes of 301 patients undergoing combined PPV/SOR with cataract surgery were enrolled.Eligible individuals were separated into four groups according to their preoperative diagnoses:silicone oil-filled eyes after PPV(group 1),epiretinal membrane(group 2),macular hole(group 3),and primary retinal detachment(RD;group 4).The variables af fecting postoperative refractive outcomes were analyzed,including age,gender,preoperative best-corrected visual acuity(BCVA),axial length(AL),keratometry average,anterior chamber depth(ACD),intraocular tamponade,and vitreoretinal pathology.The outcome measurements include the mean refractive PE and the proportions of eyes with a PE within±0.50 diopter(D)and±1.00 D.RESULTS:For all patients,the mean PE was-0.04±1.17 D,and 50.17%of patients(eyes)had a PE within±0.50 D.There was a significant difference in refractive outcomes among the four groups(P=0.028),with RD(group 4)showing the least favorable refractive outcome.In multivariate regression analysis,only AL,vitreoretinal pathology,and ACD were strongly associated with PE(all P<0.01).Univariate analysis revealed that longer eyes(AL>26 mm)and a deeper ACD were correlated with hyperopic PE,and shorter eyes(AL<26 mm)and a shallower ACD were correlated with myopic PE.CONCLUSION:RD patients have the least favorable refractive outcome.AL,vitreoretinal pathology,and ACD are strongly associated with PE in the combined surgery.These three factors affect refractive outcomes and thus can be used to predict a better postoperative refractive outcome in clinical practice.

基于In Silicon模拟消化的北极虾DPP-Ⅳ抑制肽活性分析

北极虾具有很高的营养价值,在食品领域已引起越来越多的关注。对北极虾蛋白进行In Silicon模拟消化获得寡肽,通过PeptideRanker活性评分及理化性质分析,从中筛选出具有潜在生物活性的寡肽。使用ToxinPred分析和BIOPEP-UWM生物活性预测,发现部分寡肽具有二肽基肽酶-Ⅳ(dipeptidyl peptidase-Ⅳ,DPP-Ⅳ)抑制活性,最终确定WFP(一种三肽,Trp-Phe-Pro)具有最优的DPP-Ⅳ抑制活性肽。分子对接表明,WFP和DPP-Ⅳ能够形成稳定的复合物,其结合能为-6.93 kcal/mol,进一步研究表明,WFP通过与DPP-Ⅳ S1、S2、S3三个活性口袋中的9个氨基酸残基发生相互作用而抑制其活性。本研究为阐释北极虾营养价值及生物活性肽的开发提供了理论依据。

Innovative Solutions for High-Performance Silicon Anodes in Lithium-Ion Batteries:Overcoming Challenges and Real-World Applications

Silicon(Si)has emerged as a potent anode material for lithium-ion batteries(LIBs),but faces challenges like low electrical conductivity and significant volume changes during lithiation/delithiation,leading to material pulverization and capacity degradation.Recent research on nanostructured Si aims to mitigate volume expansion and enhance electrochemical performance,yet still grapples with issues like pulverization,unstable solid electrolyte interface(SEI)growth,and interparticle resistance.This review delves into innovative strategies for optimizing Si anodes’electrochemical performance via structural engineering,focusing on the synthesis of Si/C composites,engineering multidimensional nanostructures,and applying non-carbonaceous coatings.Forming a stable SEI is vital to prevent electrolyte decomposition and enhance Li^(+)transport,thereby stabilizing the Si anode interface and boosting cycling Coulombic efficiency.We also examine groundbreaking advancements such as self-healing polymers and advanced prelithiation methods to improve initial Coulombic efficiency and combat capacity loss.Our review uniquely provides a detailed examination of these strategies in real-world applications,moving beyond theoretical discussions.It offers a critical analysis of these approaches in terms of performance enhancement,scalability,and commercial feasibility.In conclusion,this review presents a comprehensive view and a forward-looking perspective on designing robust,high-performance Si-based anodes the next generation of LIBs.

Intraocular Silicone Oil Removed after 10 Years: A Case Report

Background: Silicone oil (SO) has been demonstrated with concrete efficacy and safety in the therapy of complex vitreoretinal diseases. SO is schemed to be cleared within several weeks or months after tamponade, but it’s inevitable for permanent or residual SO in a fraction of patients under extremely complicated clinical conditions. Here, we presented a case of silicone oil removal after 10 years, mainly to observe the disadvantages of long-term persistence. Case presentation: A 69-year-old female with pathologic myopia denied trauma history who had undergone pars plana vitrectomy (PPV), retinal reattachment, laser, and silicone oil tamponade in 2012 presented to our hospital with eye pain and headache, no light perception of her right eye for six months. The slit-lamp biomicroscopy examination for OD indicated evident conjunctival congestion, new blood vessels invasion to the limbus, foggy edema of corneal epithelium, folds of Descemet’s membrane and corneal endothelial edema. There were obvious emulsified silicone oil particles above the anterior chamber. Goldmann’s applanation tonometry test revealed the intraocular pressure was as high as 45/17mmHg. From ocular ultrasound, we saw that the vitreous cavity was filled with silicone oil in right eye;as for the left eye, it showed marked axial elongation and posterior scleral staphyloma. We were unable to obtain more information from fundus photography and macular optical coherence tomography (OCT) due to edema of the cornea. After the silicone oil was removed successfully from her vitreous cavity, although there was no improvement in the patient’s vision (no light perception), she was still satisfied with the relief from eye pain and headache benefited from the reduction of high intraocular pressure (Goldmann’s intraocular pressure decreased to 19/14mmHg). Conclusion: Patients after PPV should remove silicone oil in time to avoid corneal damage, intraocular hypertension, lens opacity and retinal damage induced by long-term silicone tamponade.

Regulation of 2-acetyl-1-pyrroline and grain quality in early-season indica fragrant rice by nitrogen and silicon fertilization under different plantation methods

Fragrant rice has a high market value,and it is a popular rice type among consumers owing to its pleasant flavor.Plantation methods,nitrogen(N)fertilizers,and silicon(Si)fertilizers can affect the grain yield and fragrance of fragrant rice.However,the core commercial rice production attributes,namely the head rice yield(HRY)and 2-acetyl-1-pyrroline(2-AP)content of fragrant rice,under various nitrogen and silicon(N-Si)fertilization levels and different plantation methods remain unknown.The field experiment in this study was performed in the early seasons of 2018 and 2019 with two popular indica fragrant rice cultivars(Yuxiangyouzhan and Xiangyaxiangzhan).They were grown under six N-Si fertilization treatments(combinations of two levels of Si fertilizer,0 kg Si ha^(−1)(Si0)and 150 kg Si ha^(−1)(Si1),and three levels of N fertilizer,0 kg N ha^(−1)(N0),150 kg N ha^(−1)(N1),and 220 kg N ha^(−1)(N2))and three plantation methods(artificial transplanting(AT),mechanical transplanting(MT),and mechanical direct-seeding(MD)).The results showed that the N-Si fertilization treatments and all the plantation methods significantly affected the HRY and 2-AP content and related parameters of the two different fragrant rice cultivars.Compared with the Si0N0 treatment,the N-Si fertilization treatments resulted in higher HRY and 2-AP contents.The rates of brown rice,milled rice,head rice,and chalky rice of the fragrant rice also improved with the N-Si fertilization treatments.The N-Si fertilization treatments increased the activities of N metabolism enzymes and the accumulation of N and Si in various parts of the fragrant rice,and affected their antioxidant response parameters.The key parameters for the HRY and 2-AP content were assessed by redundancy analysis.Furthermore,the structural equation model revealed that the Si and N accumulation levels indirectly affected the HRY by affecting the N metabolism enzyme activity,N use efficiency,and grain quality of fragrant rice.Moreover,high N and Si accumulation directly promoted the 2-AP content or affected the antioxidant response parameters and indirectly regulated 2-AP synthesis.The interactions of the MT method with the N-Si fertilization treatments varied in the fragrant rice cultivars in terms of the HRY and 2-AP content,whereas the MD method was beneficial to the 2-AP content in both fragrant rice cultivars under the N-Si fertilization treatments.

Fabrication of a flexible microwave absorber sheet based on a composite filler with fly ash as the core filled silicone rubber

A new type of composite filler was designed by a modified sol-gel method using fly ash(FA),Fe(NO_(3))_(3)·9H_(2)O,and Ni(NO_(3))_(2)·6H_(2)O as raw materials.The composite filler was a spherical core-shell structure composed of FA as the core and NiFe_(2)O_(4)as the shell.Further,the composite filler was added into the silicone rubber to fabricate the high temperature vulcanized microwave absorption materials;X-ray diffraction,fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy,and scanning electron microscope confirmed that NiFe_(2)O_(4)was successfully coated on the surface of FA and formed a uniform and continuous coating layer.As expected,silicone rubber filled with the composite filler had a minimum reflection loss of-23.8 dB at 17.5 GHz with the thickness of 1.8 mm,while the effective absorption bandwidth was as high as 12 GHz.The addition of the composite filler greatly enhanced the microwave absorption properties of the system,which was resulted from multiple losses mechanism:interface polarization losses,magnetic losses,and multiple reflection losses.Also,silicone rubber filled with the composite filler exhibited excellent thermal stability,flexibility,environmental resistance,and hydrophobicity compared with traditional silicone rubber.Therefore,this work not only responds to the green chemistry to achieve efficient FA recovery,but also devises a new strategy to prepare microwave absorption materials with strong potential for civilian applications.

Vector fiber Bragg gratings accelerometer based on silicone compliant cylinder for low frequency vibration monitoring

Vector accelerometer has attracted much attention for its great application potential in underground seismic signal measurement. We propose and demonstrate a novel vector accelerometer based on the three fiber Bragg gratings(FBGs)embedded in a silicone rubber compliant cylinder at 120° distributed uniformly. The accelerometer is capable of detecting the orientation of vibration with a range of 0°–360° and the acceleration through monitoring the central wavelength shifts of three FBGs simultaneously. The experimental results show that the natural frequency of the accelerometer is about 85 Hz, and the sensitivity is 84.21 pm/g in the flat range of 20 Hz–60 Hz. Through experimental calibration, the designed accelerometer can accurately obtain vibration vector information, including vibration orientation and acceleration. In addition, the range of resonant frequency and sensitivity can be expanded by adjusting the hardness of the silicone rubber materials. Due to the characteristics of small size and orientation recognition, the accelerometer can be applied to low-frequency vibration acceleration vector measurement in narrow spaces.

Predictive factors of epiretinal membrane in complicated rhegmatogenous retinal detachment tamponaded with silicone oil

AIM:To determine the incidence and predictive factors for epiretinal membrane(ERM)formation in eyes with complicated primary rhegmatogenous retinal detachment(RRD)tamponaded with silicone oil(SO).METHODS:This retrospective case-control study included 141 consecutive patients with(51 eyes)and without(90 eyes)ERM formation after primary pars plana vitrectomy(PPV)and SO tamponade for complicated RRD.The risk factors for ERM were assessed using logistic regression analysis.RESULTS:The prevalence of postoperative ERM was 36.2%(51/141).Multivariate logistic regression analysis showed that the risk factors for ERM in SO-tamponaded eyes included preoperative proliferative vitreoretinopathy[PVR;odds ratio(OR),2.578;95%confidence interval(CI)1.580–4.205,P<0.001],preoperative choroidal detachment(OR,4.454;95%CI 1.369–14.498,P=0.013),and photocoagulation energy(OR,2.700;95%CI 1.047–6.962,P=0.040).The duration of the preoperative symptoms,intraocular SO tamponade time,giant retinal tear,preoperative vitreous hemorrhage,preoperative bestcorrected visual acuity,number of breaks,quadrants of RRD,axial length,and photocoagulation points were not predictive factors for ERM formation.CONCLUSION:Preoperative PVR,choroidal detachment,and photocoagulation energy are risk factors of ERM formation after complicated RRD repair.Better ophthalmic care as well as patient education are necessary for such patients with risk factors.

Multilevel carbon architecture of subnanoscopic silicon for fast‐charging high‐energy‐density lithium‐ion batteries

Silicon(Si)is widely used as a lithium‐ion‐battery anode owing to its high capacity and abundant crustal reserves.However,large volume change upon cycling and poor conductivity of Si cause rapid capacity decay and poor fast‐charging capability limiting its commercial applications.Here,we propose a multilevel carbon architecture with vertical graphene sheets(VGSs)grown on surfaces of subnanoscopically and homogeneously dispersed Si–C composite nanospheres,which are subsequently embedded into a carbon matrix(C/VGSs@Si–C).Subnanoscopic C in the Si–C nanospheres,VGSs,and carbon matrix form a three‐dimensional conductive and robust network,which significantly improves the conductivity and suppresses the volume expansion of Si,thereby boosting charge transport and improving electrode stability.The VGSs with vast exposed edges considerably increase the contact area with the carbon matrix and supply directional transport channels through the entire material,which boosts charge transport.The carbon matrix encapsulates VGSs@Si–C to decrease the specific surface area and increase tap density,thus yielding high first Coulombic efficiency and electrode compaction density.Consequently,C/VGSs@Si–C delivers excellent Li‐ion storage performances under industrial electrode conditions.In particular,the full cells show high energy densities of 603.5 Wh kg^(−1)and 1685.5 Wh L^(−1)at 0.1 C and maintain 80.7%of the energy density at 3 C.

A Boron-based Adhesion Aid for Efficient Bonding of Silicone Rubber and Epoxy Resin

We improved the adhesion between silicon based insulating materials and epoxy resin composites by adding the adhesion promoter cycloborosiloxane(BSi,cyclo-1,3,3,5,7,7-hexaphenyl-1,5-diboro-3,7-disiloxane).The experimental results show that the addition of BSi in the silicone rubber(SR)system significantly increases the tensile shear strength between BSi and epoxy resin(EP),reaching 309%of the original value.On this basis,the mechanism of BSi to enhance the adhesion effect was discussed.The electron deficient B in BSi attracted the electron rich N and O in EP to enhance the chemical interaction,combined with the interfacial migration behavior in the curing process,to improve the adhesion strength.This study provides the design and synthesis ideas of adhesive aids,and a reference for further exploring the interface mechanism of epoxy resin matrix composites.

Retrolaminar migration as a complication of intraocular silicone oil injection detected on unenhanced CT

AIM:To describe the clinical and radiologic features of retrolaminar migration silicone oil(SiO)and observe the dynamic position of ventricular oil accumulation in supine and prone.METHODS:For this retrospective study,29 patients who had a history of SiO injection treatment and underwent unenhanced head computed tomography(CT)were included from January 2019 to October 2022.The patients were divided into migration-positive and negative groups.Clinical history and CT features were compared using Whitney U and Fisher’s exact tests.The dynamic position of SiO was observed within the ventricular system in supine and prone.CT images were visually assessed for SiO migration along the retrolaminar involving pathways for vision(optic nerve,chiasm,and tract)and ventricular system.RESULTS:Intraocular SiO migration was found in 5 of the 29 patients(17.24%),with SiO at the optic nerve head(n=1),optic nerve(n=4),optic chiasm(n=1),optic tract(n=1),and within lateral ventricles(n=1).The time interval between SiO injection and CT examination of migration-positive cases was significantly higher than that of migration-negative patients(22.8±16.5mo vs 13.1±2.6mo,P<0.001).The hyperdense lesion located in the frontal horns of the right lateral ventricle migrated to the fourth ventricle when changing the position from supine to prone.CONCLUSION:Although SiO retrolaminar migration is unusual,the clinician and radiologist should be aware of migration routes.The supine combined with prone examination is the first-choice method to confirm the presence of SiO in the ventricular system.

Ultrafast dynamics of femtosecond laser-induced high spatial frequency periodic structures on silicon surfaces

Femtosecond laser-induced periodic surface structures(LIPSS)have been extensively studied over the past few decades.In particular,the period and groove width of high-spatial-frequency LIPSS(HSFL)is much smaller than the diffraction limit,making it a useful method for efficient nanomanufacturing.However,compared with the low-spatial-frequency LIPSS(LSFL),the structure size of the HSFL is smaller,and it is more easily submerged.Therefore,the formation mechanism of HSFL is complex and has always been a research hotspot in this field.In this study,regular LSFL with a period of 760 nm was fabricated in advance on a silicon surface with two-beam interference using an 800 nm,50 fs femtosecond laser.The ultrafast dynamics of HSFL formation on the silicon surface of prefabricated LSFL under single femtosecond laser pulse irradiation were observed and analyzed for the first time using collinear pump-probe imaging method.In general,the evolution of the surface structure undergoes five sequential stages:the LSFL begins to split,becomes uniform HSFL,degenerates into an irregular LSFL,undergoes secondary splitting into a weakly uniform HSFL,and evolves into an irregular LSFL or is submerged.The results indicate that the local enhancement of the submerged nanocavity,or the nanoplasma,in the prefabricated LSFL ridge led to the splitting of the LSFL,and the thermodynamic effect drove the homogenization of the splitting LSFL,which evolved into HSFL.