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.

Reduction of signal reflection along through silicon via channel in high-speed three-dimensional integration circuit

The through silicon via （TSV） technology has proven to be the critical enabler to realize a three-dimensional （3D） gigscale system with higher performance but shorter interconnect length. However, the received digital signal after trans- mission through a TSV channel, composed of redistribution layers （RDLs）, TSVs, and bumps, is degraded at a high data-rate due to the non-idealities of the channel. We propose the Chebyshev multisection transformers to reduce the signal reflec- tion of TSV channel when operating frequency goes up to 20 GHz, by which signal reflection coefficient （$11） and signal transmission coefficient （$21） are improved remarkably by 150% and 73.3%, respectively. Both the time delay and power dissipation are also reduced by 4% and 13.3%, respectively. The resistance-inductance-conductance-capacitance （RLGC） elements of the TSV channel are iterated from scattering （S）-parameters, and the proposed method of weakening the signal reflection is verified using high frequency simulator structure （HFSS） simulation software by Ansoft.

An analytical model of thermal mechanical stress induced by through silicon via

We present an accurate through silicon via （TSV） thermal mechanical stress analytical model which is verified by using finite element method （FEM）. The results show only a very small error. By using the proposed analytical model, we also study the impacts of the TSV radius size, the thickness, the material of Cu diffusion barrier, and liner on the stress. It is found that the liner can absorb the stress effectively induced by coefficient of thermal expansion mismatch. The stress decreases with the increase of liner thickness. Benzocyclobutene （BCB） as a liner material is better than SiO2. However, the Cu diffusion barrier has little effect on the stress. The stress with a smaller TSV has a smaller value. Based on the analytical model, we explore and validate the linear superposition principle of stress tensors and demonstrate the accuracy of this method against detailed FEM simulations. The analytic solutions of stress of two TSVs and three TSVs have high precision against the finite element result.

Through-silicon-via crosstalk model and optimization design for three-dimensional integrated circuits

Through-silicon-via （TSV） to TSV crosstalk noise is one of the key factors affecting the signal integrity of three- dimensional integrated circuits （3D ICs）. Based on the frequency dependent equivalent electrical parameters for the TSV channel, an analytical crosstalk noise model is established to capture the TSV induced crosstalk noise. The impact of various design parameters including insulation dielectric, via pitch, via height, silicon conductivity, and terminal impedance on the crosstalk noise is analyzed with the proposed model. Two approaches are proposed to alleviate the TSV noise, namely, driver sizing and via shielding, and the SPICE results show 241 rnV and 379 mV reductions in the peak noise voltage, respectively.

Preparation and properties of porous silicon carbide ceramics through coat-mix and composite additives process

The core-shell structure silicon-resin precursor powders were synthesized through coat-mix process and addition of Al2O3-SiO2-Y2O3 composite additives.A series of porous silicon carbide ceramics were produced after molding,carbonization and sintering.The phase,morphology,porosity,thermal conductivity,thermal expansion coefficient,and thermal shock resistance were analyzed.The results show that porous silicon carbide ceramics can be produced at low temperature.The grain size of porous silicon carbide ceramic is small,and the thermal conductivity is enhanced significantly.Composite additives also improve the thermal shock resistance of porous ceramics.The bending strength loss rate after 30 times of thermal shock test of the porous ceramics which were added Al2O3-SiO2-Y2O3 and sintered at 1 650 ℃ is only 6.5%.Moreover,the pore inside of the sample is smooth,and the pore size distribution is uniform.Composite additives make little effect on the thermal expansion coefficient of the porous silicon carbide ceramics.

基于TSV技术的硅基高压电容器

以微机电系统(MEMS)工艺设计并制作了一种基于TSV技术的高压电容器。给出了电容器的结构形式,理论分析计算了电容器的容值参数,设计得到了容值为2 nF,芯片尺寸为2 mm×2 mm×0.3 mm的硅基电容器。提出一套MEMS工艺的硅基电容器的制作流程,实现了电容器的工艺制作及测试。测试结果表明,获得的高压电容器的容值与设计值基本一致,击穿电压可以达到280 V。硅基高压电容器具有电容密度高、一致性好、易生产的特点,适合高压电子系统的应用发展需求。

TSV阵列在温度循环下的晶格变化对电学性能影响的研究

针对TSV(Through Silicon Via,硅通孔)热机械可靠性较差且其结构特性变化对电学性能影响情况不明的问题,基于一种TSV阵列叉指电极对样品开展了-55~125℃的温度循环试验,测试了温循后阵列电极的电学性能与边界绝缘性能变化,跟踪测试了TSV铜柱的几何尺寸变化,对比分析了试验前后TSV结构的形貌和晶格特性等衍化规律。结果表明,温度循环载荷导致了TSV-Cu晶粒向上生长、铜柱体积变大、微观结构缺陷产生以及电学性能退化;此外,还定量地构建了晶格特性变化对TSV阵列电极电学性能影响的关系架构,具有一定的工程意义。

一种基于分压电路的绑定后TSV测试方法

对硅通孔(Through Silicon Via,TSV)进行绑定后测试可以有效地提升三维集成电路的性能和良率。现有的测试方法虽然对于开路和桥接故障的测试能力较高,但是对于泄漏故障的测试效果较差,并且所需的总测试时间较长。对此,提出了一种基于分压电路的TSV绑定后测试方法。该方法设计了一种分压电路,进行泄漏故障测试时可以形成一条无分支的电流路径,有效提高了对泄漏故障的测试能力。此外,该方法测试开路故障和泄漏故障时的电流路径不会相互干扰,可以同时测试相邻TSV的开路故障和泄漏故障。实验结果表明,该方法可以测试10 kΩ以下的弱泄漏故障,并且在工艺偏差下依然能够保持较高的测试能力。相比同类测试方法,该方法所需面积开销更小,所需总测试时间更少。

Alleviation of Chromium Toxicity by Silicon Addition in Rice Plants

The alleviatory effect of silicon （Si） on chromium （Cr） toxicity to rice plants was investigated using a hydroponic experiment with two Cr levels （0 and 100μmol L-1）,three Si levels （0,1.25,and 2.5 mmol L-1） and two rice genotypes,differing in grain Cr accumulation （Dan K5,high accumulation and Xiushui 113,low accumulation）.The results showed that 100μmol L-1 Cr treatment caused a marked reduction of seedling height,dry biomass,soluble protein content,and root antioxidant enzyme activity,whereas significantly increased Cr concentration and TBARS （thiobarbituric acid reactive substances） content.However,the reductions of seedling height,dry biomass,and soluble content were greatly alleviated due to Si addition to the culture solution.Compared with the plants treated with Cr alone,Si addition markedly reduced Cr uptake and translocation in rice plants.No significant differences were observed between the two Si treatments （1.25 and 2.5 mmol L-1） in shoot Cr concentration and Cr translocation factor.Under the treatment of 100μmol L-1 Cr＋2.5 mmol L-1 Si,higher root Cr concentration but lower shoot Cr concentration and Cr translocation factor were observed in Dan K5 than those in Xiushui 113,indicating that the beneficial effect of Si on inhibiting Cr translocation was more pronounced in Dan K5 than in Xiushui 113.Si addition also alleviated the reduction of antioxidative enzymes （superoxide dismutase （SOD） and ascorbate peroxidase （APX） in leaves;catalase （CAT） and APX in roots） and the increase of TBARS content in the Cr-stressed plants.Furthermore,the beneficial effects of Si on activities of antioxidative enzymes under Cr stress were genotype-dependent.The highest activities of SOD,POD （guaiacol peroxidase）,CAT,and APX in leaves occurred in the treatment of 100μmol L-1 Cr＋2.5 mmol L-1 Si for Xiushui 113 and in the treatment of 100μmol L-1 Cr＋1.25 mmol L-1 Si for Dan K5.The beneficial effect of Si on alleviating oxidative stress was much more pronounced in Dan K5 than in Xiushui 113.It may be concluded that Si alleviates Cr toxicity mainly through inhibiting the uptake and translocation of Cr and enhancing the capacity of defense against oxidative stress induced by Cr toxicity.

Purification of solar cell silicon materials through filtration

Silicon is the material most commonly used in the manufacturing of photovoltaic (PV) cells. In the current study, laboratory experiments of purification of solar cell silicon materials through filtration are carried out. Inclusion removal from silicon was investigated. The purpose is to achieve clean silicon materials for solar cells. Silicon samples and filter samples were analyzed using microscope observation, EPMA, and X-ray detection. Silicon nitride (Si3N4) and silicon carbide (SiC) particles are the main non-metallic inclusions present in top-cut silicon scrap. Almost all inclusions larger than 10 μm can be removed from silicon by the porous foam filter. In mass fraction, more than 90% inclusions are removed. Si3N4 particles are mainly removed on the top surface of the filter, and SiC particles are mainly removed by entering the pores and attaching to the filter material. SiC inclusions are not only simply attached on the surface of the filter material, but are found also inside the filter material. There are SiC bridges near the filter materials. These bridges may fill the spaces between filter material, and this will further retard inclusions passing through the filter. Three-dimensional turbulent fluid flow and inclusion motion in the filter was calculated. Both experimental observation and fluid flow simulation indicate that most of the inclusions are entrapped at the upper part of the filter.

Efficacy and safety of active silicone oil removal through a 23-gauge transconjunctival cannula using an external vacuum pump

AIM: To evaluate the efficacy and safety of active removal of silicone oil with low and high viscosity through a 23-gauge transconjunctival cannula using an external vacuum pump.METHODS: This study was conducted as a prospective, interventional case series. A total of 22 eyes of 21 patients [1000 centistokes(c St): 17 eyes, 5700 c St:5 eyes] were included in this study. All patients underwent active silicone oil removal via the entire lumen of a 23-gauge microcannula with suction pressure of a650-700 mm Hg vacuum using an external vacuum pump. A tubing adaptor from the Total Plus Pak誖(Alcon,Fort Worth, USA) was used to join the microcannula and silicone vacuum tube connected to an external vacuum pump. Main outcome measures were mean removal time,changes of intraocular pressure(IOP) and visual acuity,and intraoperative and postoperative complications.RESULTS: Mean removal time(min) was 1.49±0.43 for1000 c St and 7. 12 ± 1. 27 for 5700 c St. The IOP was18.57±7.48 mm Hg at baseline, 11.68 ±4.55 mm Hg at day1 postoperatively(P <0.001), and 15.95±4.92, 16.82±3.81,17.41 ±3.50, and 17.09 ±3.01 mm Hg after one week, one month, three months, and six months, respectively. All patients showed improved or stabilized visual acuity.There was no occurrence of intraoperative or postoperative complications during the follow up period.CONCLUSION: This technique for active removal of silicone oil through a 23-gauge cannula using an external vacuum pump is fast, effective, and safe as well as economical for silicone oil with both low and high viscosity in all eyes with pseudophakia, aphakia, or phakia.

A modified approach to actively remove high viscosity silicone oil through 23-gauge cannula

AIM：To report a simple approach to actively remove high viscosity silicone oil through a 23-gauge cannula via pars plana.METHODS：Forty-eight eyes of 48 patients underwent silicone oil（5700 centistokes） removal（SOR） were enrolled.A section of blood transfusion set was prepared to connect a standard 23-gauge cannula and vitrectomy machine.Silicone oil was removed with suction of500-mm Hg vacuum through the cannula.Main outcome measures were SOR duration,number of sutured sites,intraocular pressure（IOP）,best-corrected visual acuity（BCVA）,and complications.RESULTS：Silicone oil was successfully removed in all cases.The mean SOR time was 5.70±0.85 min.Nine eyes（18.75%） needed suture partial sclerotomies.No intraoperative complications were noted.Transient hypotony（≤8 mm Hg） was seen in 3 eyes（6.25%） on postoperative day 1,but all resolved within 1wk.Retinal reattachment was achieved in all cases and no other postoperative complications were noted during 3-month following-up.BCVA at the final visit improved or stabilized in all patients comparing to the preoperative level.CONCLUSION：Active removal of high viscosity silicone oil through a 23-gauge instrument cannula jointed with blood transfusion set is a practical and reliable technique when considering two sides of efficacy and safety.

基于两步刻蚀工艺的锥形TSV制备方法

以硅通孔(TSV)为核心的2.5D/3D封装技术可以实现芯片之间的高速、低功耗和高带宽的信号传输。常见的垂直TSV的制造工艺复杂,容易造成填充缺陷。锥形TSV的侧壁倾斜,开口较大,有利于膜层沉积和铜电镀填充,可降低工艺难度和提高填充质量。在相对易于实现的刻蚀条件下制备了锥形TSV,并通过增加第二步刻蚀来改善锥形TSV形貌。成功制备了直径为10~40μm、孔口为喇叭形的锥形TSV。通过溅射膜层和铜电镀填充,成功实现了直径为15μm、深度为60μm的锥形TSV的连续膜层沉积和完全填充,验证了两步刻蚀工艺的可行性和锥形TSV在提高膜层质量和填充效果方面的优势。为未来高密度封装领域提供了一种新的TSV制备工艺,在降低成本的同时提高了2.5D/3D封装技术的性能。

基于温度传感阵列的TSV内部缺陷检测技术研究

在TSV三维集成领域,由于TSV内部缺陷的微小化和检测的不可接触性,寻找一个无损、灵敏且高效的内部缺陷检测方法尤为重要。针对这一挑战,提出了一种基于温度传感阵列的TSV内部缺陷检测方法。内部缺陷对TSV三维封装芯片的外部温度分布产生了影响,这些温度分布呈现出有规律的变化,每一种缺陷类型都会导致外部温度分布产生不同的偏差。利用温度传感阵列测量这些分布变化对缺陷进行有效的识别与分类。根据工作状态下的芯片产生的热信号以揭示其内部的缺陷信息,设计了基于温度传感阵列的检测系统。通过理论分析与仿真模拟,构建了模拟芯片工作状态下的温度分布和热变化的模型。实验中,以芯片样品的样本制备和测试平台搭建为基础,同时利用分类识别模型成功实现了对内部缺陷的有效分类,准确率高达99.17%。这种检测方法为高密度和微型化芯片的可靠性分析和故障诊断提供了一个经济高效的新途径。

Sustainable silicon anodes facilitated via a double-layer interface engineering: Inner SiOx combined with outer nitrogen and boron co-doped carbon

Silicon-based(Si)materials are promising anodes for lithium-ion batteries(LIBs)because of their ultrahigh theoretical capacity of 4200 mA h g^(−1).However,commercial applications of Si anodes have been hindered by their drastic volume variation(∼300%)and low electrical conductivity.Here,to tackle the drawbacks,a hierarchical Si anode with double-layer coatings of a SiOx inner layer and a nitrogen(N),boron(B)co-doped carbon(C-NB)outer layer is elaborately designed by copyrolysis of Si-OH structures and a H3BO_(3)-doped polyaniline polymer on the Si surface.Compared with the pristine Si anodes(7mA h g^(−1) at 0.5 A g^(−1) after 340 cycles and 340 mA h g^(−1) at 5 A g^(−1)),the modified Si-based materials(Si@SiOx@C-NB nanospheres)present su perior cycling stability(reversible 1301 mA h g^(−1) at 0.5 A g^(−1) after 340 cycles)as well as excellent rate capability(690mA h g^(−1) at 5 A g^(−1))when used as anodes in LIBs.The unique double-layer coating structure,in which the inner amorphous SiOx layer acts as a buffer matrix and the outer defect-rich carbon enhances the electron diffusion of the whole anode,makes it possible to de liver excellent electrochemical properties.These results indicate that our double-layer coating strategy is a promising approach not only for the devel opment of sustainable Si anodes but also for the design of multielement-doped carbon nanomaterials.

Fabrication of multi-shell coated silicon nanoparticles via in-situ electroless deposition as high performance anodes for lithium ion batteries

Si-based materials have been extensively studied because of their high theoretical capacity,low working potential,and abundant reserves,but serious initial irreversible capacity loss and poor cyclic performance resulting from large volume change of Si during lithiation and delithiation processes restrict their widespread application.Herein,we report the preparation of multi-shell coated Si(DS-Si)nanocomposites by in-situ electroless deposition method using Si granules as the active materials and copper sulfate as Cu sources.The ratio of Si and Cu was readily tuned by varying the concentration of copper sulfate.The multi-shell(Cu@CuxSi/SiO2)coating on Si surface promotes the formation of robust and dense SEI films and the transportation of electron.Thus,the obtained DS-Si composites exhibit an initial coulombic efficiency of 86.2%,a capacity of 1636 mAh g^-1 after 100 discharge-charge cycles at 840 mA g^-1,and an average charge capacity of 1493 mAh g^-1 at 4200 mA g^-1.This study provides a low-cost and large-scale approach to the preparation of nanostructured Si-metal composites anodes with good electrochemical performance for lithium ion batteries.

基于倾斜旋转方法磁控溅射制备TSV阻挡层

硅通孔(TSV)是实现三维集成的关键技术,在TSV侧壁制备连续和均匀的阻挡层至关重要。提出了一种磁控溅射制备TSV侧壁阻挡层的方法,将溅射基台倾斜一定角度并水平匀速旋转,使溅射离子的掉落方向与TSV侧壁不平行,靶材离子更容易溅射沉积在TSV侧壁,使得TSV侧壁都能被溅射到,更有利于制备连续和均匀的阻挡层。使用Ti靶进行直流磁控溅射,优化溅射电流和溅射气压,通过扫描电子显微镜(SEM)对TSV侧壁阻挡层的形貌进行表征分析。随着溅射电流和溅射气压的增大,阻挡层的厚度会增加,但是溅射气压的增大使得溅射钛晶粒变得细长,从而导致阻挡层的均匀性和致密性变差。

Influence of Yb_2O_3-MgO on Mechanical Properties and Thermal Conductivity of Silicon Nitride Ceramics via Gas Pressure Sintering

In this work,Yb2O3 and Mg O were used as sintering aids in preparing silicon nitride ceramics by gas pressure sintering（ 0. 6 MPa N2atmosphere） to investigate how the amounts of Yb2O3- Mg O influence the mechanical properties and thermal conductivity of silicon nitride ceramics. The total contents of Yb2O3- Mg O added were 1 mol%,2 mol%,4 mol%,6 mol%,8 mol%,10 mol%,12 mol%,14 mol%,keeping the Yb2O3-Mg O molar ratio of 1 ∶ 1 steadily. Curves of the relative density,thermal conductivity and bending strength plotted against the aids content present a ‘mountain＇shape with a maximum at nearly 10 mol% aids. The fracture toughness increased with the amounts of additives up to10 mol% and decreased slightly thereafter. The mechanical properties and thermal conductivity were almost proportional to the amount of the additives before10 mol%. When the content of aids exceeded 10 mol%,it would weaken the mechanical properties and thermal conductivity of the ceramics. The optimum content of Yb2O3- Mg O was 10 mol% by gas pressure sintering（ 0. 6MPa） at 1 850 ℃ for 4 h,which led to a relative density of 98. 9%,a flexural strength of（ 966 ± 38）MPa as well as a fracture toughness of（ 6. 29 ± 0. 29）MPa·m1 /2and thermal conductivity of 82 W /（ m·K）.

Enhancing Drought Tolerance in Wheat through Improving Morpho- Physiological and Antioxidants Activities of Plants by the Supplementation of Foliar Silicon

The main objective of the research is to assess the role of foliar application of silicon(Si)for enhancing the survival ability of wheat under drought stress through improving its morphology,physicochemical and antioxidants activities.Treatments were five doses of Si at the rate of 2,4,6 and 8 mM and a control.After completion of seeds germination,pots were divided into four distinct groups at various field capacity(FC)levels,such as 100%FC(well-irrigated condition),75%FC(slight water deficit),50%FC(modest water deficit)and 25%FC(severe water deficit stress condition).Foliar application of Si at the rate of 2,4,6 and 8 mM and a control were given after 30 days of sowing at the tillering stage of wheat.Findings of the present investigation indicated that increasing the level of water deficit stress reduced the morphological parameters(such as root and shoot fresh and dry-biomass weight)and physico-biochemical events((such as chlorophyll contents by estimating SPAD value),total free amino acid(TFAA),total soluble sugar(TSS),total soluble protein(TSP),total proline(TP),CAT(catalase),POD(peroxidase),SOD(superoxide dismutase)and APX(ascorbate peroxidase))of wheat;while foliar application of Si at 6 mM at tillering stage enhanced the drought tolerance in wheat by increasing morphology and physiochemical characters under all levels of drought stress.Similarly,antioxidants activities in wheat also enhanced by the application of Si at 6 mM under normal as well as all drought stress levels.There-fore,it may be concluded that foliar application of Si at 6 mM at the tillering stage of wheat is an important indication for increasing the drought tolerance by improving the morphology,physico-biochemical and antioxidants activities in plants under deficit water(drought)conditions.

Simple Fabrication of Hierarchical Micro/Nanostructure Superhydrophobic Surface with Stable and Superior Anticorrosion Silicon Steel via Laser Marking Treatment

To improve the weak corrosion resistance of silicon steel to acid solution and alkaline solution with high temperature,a stable hierarchical micro/nanostructure superhydrophobic surface with myriad irregular micro-scale hump and sheet-like nanostructure was successfully prepared on silicon steel by a simple,efficient and facile operation in large-area laser marking treatment.The morphology,composition,wettability of the as-prepared surface were studied.The superhydrophobic performance of the surface was investigated as well.Additionally,the corrosion resistance of the superhydrophobic surface to acidic solutions at room temperature and alkaline solutions at high temperature (80 ℃) was carefully explored.The corrosion resistance mechanism was clarified.Moreover,considering the practical application of the surface in the future,the hardness of the hierarchical micro/nanostructure superhydrophobic surface was studied.The experimental results indicate that the hierarchical micro/nanostructure surface with texture spacing of 100 μm treated at laser scanning speed of 100 mms/ presents superior superhydrophobicity after decreasing surface energy.The contact angle can be as high as 156.6°.Additionally,the superhydrophobic surface provide superior and stable anticorrosive protection for silicon steel in various corrosive environments.More importantly,the prepared structure of the surface shows high hardness,which ensures that the surface of the superhydrophobic surface cannot be destroyed easily.The surface is able to maintain great superhydrophobic performance when it suffers from slight impacting and abrasion.