Silicone Oil Research Articles

Endocytosis-Inspired Zwitterionic Gel Tape for High-Efficient and Sustainable Underoil Adhesion.

Marine oil exploration is important yet greatly increases the risk of oil leakage, which will result in severe environment pollution and economic losses. It is an urgent need to develop effective underoil adhesives. However, realizing underoil adhesion is even harder than those underwater, due to the stubborn attachment of a highly viscous oil layer on target surface. Here, inspired by endocytosis, a tough gel tape composed of zwitterionic polymer network and zwitterionic surfactants is developed. The amphiphilic surfactants can form micelle to capture the oil droplets and transport them from the interface to gel via electrostatic attraction of polymer backbone, mimicking the endocytosis and achieving robust underoil adhesion. Benefiting from the oil-resistance of polymer backbone, the gel further realizes a combination of i) long-term adhesion with high durability, ii) repeated adhesion in oil, and iii) renewable adhesion efficiency after exhausted use. The tape exhibits an ultra-high adhesive toughness of 2446.86 J m-2 to stainless steel in silicone oil after 30 days' oil-exposure; such value of adhesive toughness surpasses many of those achieved in underwater adhesion and is greater than underoil adhesion performance of commercial tape. The strategy illustrated here will motivate the design of sustainable and efficient adhesives for wet environments.

A robust antagonistically assembled triboelectric nanogenerator based on dead‐end closed pore through a one‐step improved phase separation

AbstractThe ongoing global energy crisis presents a significant challenge all over the world. In this study, triboelectric nanogenerator (TENG) made of recyclable thermoplastic polycarbonate has been proposed as a promising environmentally friendly solution due to its potential capability to convert low‐frequency mechanical energy sources such as human motion and ocean waves into electricity with potential applications including powering wearable electronic devices and self‐powered sensors. We introduce an antagonistically structured TENG (A‐TENG) composed of honeycomb porous polycarbonate (hc‐PC) and convex‐patterned dimethylsiloxane, employing a novel one‐stage improved phase separation method. This A‐TENG overcomes the demerits of others thanks to its high surface contact area, simplified fabrication process, enhanced energy conversion efficiency, and cost‐effectiveness, requiring minimal investment. More importantly, this work utilized hc‐PC as a framework for slippery liquid‐infused porous surface (SLIPS) based TENG owing to the special honeycomb porous structure to impregnate silicon oil within pore arrays and mechanically support the whole system. The practical application of SLIPS‐TENG was demonstrated while deployed on the house rooftop to harvest raindrop energy and act as a rain detection sensor.

Novel fillers for wearable technology: Impact of titanium carbide and thinners on room temperature vulcanized silicone rubber composites

Wearable technology has emerged as a robust pathway to achieve smart functionalities in healthcare, sports, fitness, and beyond. This study investigates the mechanical and electromechanical properties of silicone rubber (SR) composites. The SR was reinforced with titanium carbide (TiC) and modified with varying (room-temperature vulcanized) RTV-thinner (silicone oil) concentrations. RTV-SR was utilized, which cures at room temperature to form a flexible, durable, and moldable rubber widely used for sealing, bonding, and making molds. The addition of TiC enhanced tensile strength from 0.5 MPa (control) to 0.59 MPa (5 phr of TiC), and tensile modulus from 0.41 MPa to 0.51 MPa. However, the thinner inclusion reduced tensile properties. For instance, the T10 sample (10 phr thinner) showed a tensile strength of 0.51 MPa and a tensile modulus of 0.29 MPa making the composites soft. Thinner addition also increased ductility, with fracture strains rising from 151 % (control) to 217 % (T10). Compressive strength followed a similar trend, with the control and 5 phr TiC samples exhibiting compressive strengths of 0.18 MPa and 0.17 MPa, respectively, which decreased to 0.12 MPa for the T20 sample. Under cyclic loading, TiC-filled samples showed consistent load patterns, while thinner addition resulted in increased energy dissipation and reduced stiffness. Electromechanical analysis revealed that TiC 5 phr samples exhibited stable piezoelectric responses, with voltage outputs increasing from ±0.1 mV at 15 % strain to ±1.0 mV at 40 % strain. The T5 samples demonstrated significant voltage improvements, generating ±2.5 mV at 15 % strain and ±5 mV at 40 % strain. Long-term cyclic tests confirmed the stability of T5 samples, maintaining voltage outputs of −1.5 mV to 1.5 mV over 50 minutes. Response time analysis indicated faster response times for TiC 5 phr samples, decreasing from 145 ms at 15 % strain to 102 ms at 40 % strain, while thinner addition led to longer response times. Real-time electromechanical tests under mechanical study showed that T5 samples achieved optimal performance with voltage peaks up to ±2.4 mV under thumb pressing. These findings highlight the trade-off between mechanical strength and flexibility, suggesting that an optimal balance of TiC and thinner enhances the properties of silicone rubber composites for applications in wearable technology and sensors.

Preparation and performance study of silicon modified polyurethane-based magnetorheological elastomeric polishing pad

Abstract By employing Magnetorheological Elastomers (MREs) as polishing pads for chemical mechanical polishing (CMP), the magnetorheological properties are utilized to effectively control the flexible removal of materials in CMP. This study presents a method for preparing a Silicon modified Polyurethane (SPU)-based MRE polishing pad, aimed at demonstrating improved magnetorheological properties while preserving mechanical properties. The SPU-based MRE polishing pad was synthesized through the copolymerization of hydroxypropyl silicone oil and polyurethane prepolymers, with subsequent evaluation of its mechanical properties and polishing performance. Fourier Transform Infrared (FTIR) analysis confirmed the successful incorporation of the soft polydimethylsiloxane main chain from organosilicon into the polyurethane main chain, forming a soft segment that intertwines with the polyurethane main chain to create a soft-hard segment crosslinked structure. Comparison to Polyurethane (PU)-based MRE, SPU exhibits significantly reduced hardness but improved wear resistance, as well as enhanced resistance to acid and alkali corrosion. Due to the presence of a soft matrix, SPU shows better magnetorheological effects than PU-based MRE. Under a magnetic field intensity of 845 mT, the magnetorheological effect of PU-based MRE is only 18%, while Si-15.96 and Si-16.79 SPU-based MREs can reach 84% and 110%, respectively. Although the Material Removal Rate (MRR) of single-crystal SiC decreases after polishing with SPU compared to PU-based MRE, a higher surface quality is achieved, and the glazing degree of the polishing pad is significantly reduced. In the magnetic field-assisted polishing of single crystal SiC, the MRR increased by 38.4% when polished with an SPU-based MRE polishing pad, whereas the MRR was only 8.7% when polished with a PU-based MRE polishing pad. This study provides further evidence for the development and application of MRE in CMP.

Ultralong room temperature phosphorescence with multicolor afterglow achieved in a harsh polymeric viscous flow state.

Polymer-based ultralong room temperature phosphorescence (RTP) is more attractive than that of organic small molecules. However, the intrinsic contradictions between the motion of the chain and the stability of phosphors' triplet excitons make achieving ultralong lifetime in polymeric systems a big challenge. Herein, we have achieved ultralong RTP emission in a polymeric viscous flow state with free chain motion through a facile B-O click reaction among boric acid, polyvinyl alcohol, and hydroxyl silicone oil. The yielded RTP putties (RTPPs) exhibited long lifetimes under ambient conditions (up to 2.39 s), surpassing those of all reported elastic RTP polymers and most glassy RTP polymers. Furthermore, multi-color afterglow can be achieved in RTPPs using the triplet-to-singlet Förster resonance energy transfer strategy. Impressively, utilizing viscous liquid features combined with RTP performance, RTPPs can be easily applied in complex models, handiwork, and anti-counterfeiting. Therefore, this progress, achieving a long phosphorescence lifetime in a viscous flow state, greatly expands the application scope of polymeric RTP materials and further compels a conceptual advance of polymeric RTP.

Efficacy of Foldable Capsular Vitreous Body Implants Filled With Light or Heavy Silicone Oil in the Treatment of Silicone Oil-dependent Eyes.

The purpose of this study was to compare the clinical efficacy of foldable capsular vitreous body (FCVB) filled with either light or heavy silicone oil and the incidence of complications after their implantation for the treatment of severe ocular trauma and silicone oil-dependent eyes. FCVB filled with either light (n = 16) or heavy (n = 8) silicone oil was implanted in 24 patients. During the 12-month follow-up period, the intraocular pressure, final best-corrected visual acuity, retinal reattachment condition, position of the FCVB, and complications were assessed. All surgeries were performed without issue. There was no significant difference in preoperative and postoperative best-corrected visual acuity between the two groups. A significant improvement in the intraocular pressure was observed after surgery in both the light silicone oil (P = 0.029) and heavy silicone oil (P = 0.035) groups. None of the patients developed displacement or prolapse of the FCVB. The most common early and late postoperative complications were postoperative hemorrhage (33.3%) and corneal opacification (50%), respectively. FCVB filled with heavy silicone oil can be used as a supplemental therapy for patients who have lost the anterior segment of their eye, have lesions of the inferior retina, or cannot maintain the prone position for various reasons. Implantation of FCVB combined with heavy silicone oil compensates for the shortcomings of this with light silicone oil, providing patients with more personalized treatment.

Preoperative OCT-Derived Nasal Perifoveal Retinal Nerve Fiber Layer Thickness Predictively Correlates Long-Term Visual Acuity Post Oil Removal Surgery.

With the widespread application of silicone oil in vitreoretinal surgery, the purpose of this study was to determine the risk factors of long-term vision loss 12months post oil removal in retina-detached eyes treated with vitrectomy and silicone oil tamponade. Of the 592 patients approached, eligible eyes completed the investigation up to 12months post-oil-removal. Eligible eyes underwent pars-plana vitrectomy following oil tamponade. Oil removal was performed after 3 to 28months in different individuals, under the condition that the retina has reattached as well as the hemorrhage and inflammation has dissolved. Postoperative best-corrected visual acuity (BCVA), age, sex, and interval between tamponade and removal were recorded, and retinal thickness was determined using optical coherence tomography (OCT). Fifty eyes of 50 participants aged 31 to 83years were enrolled. BCVA (LogMAR) 12months post-oil-removal improved in 25 of 40 (62.5%) patients, varying from 0.05 (20/22) to 1.0 (20/200) (mean ± SD = 0.55 ± 0.32). Pre-oil-removal nasal perifoveal retinal nerve fiber layer thickness varied from 16 to 83µm (38.40 ± 18.50), and was significantly linked with post-oil-removal BCVA (0.5%, 95% confidence interval 0.0%-1.0%; P = 0.046). This study demonstrates the risk factors and prognosis of visual function after long-term regeneration post vitrectomy, oil tamponade, and oil removal, thereby underscoring the need for a complete, dynamic examination of retinal structure via OCT measurement. Related studies should be conducted on a larger scale to facilitate the stratification of late-period vision damage in retina-detached eyes. This study developed OCT-based clinical markers for the postoperative visual prognosis of eyes affected by retinal detachment.

Clinical characteristics and outcomes of band keratopathy: a 10-year retrospective analysis

Background: Band keratopathy is a chronic, degenerative corneal disease resulting from gradual calcium deposition in the superficial cornea. Herein, we report the spectrum of causes, treatment outcomes, and recurrence rates of band keratopathy at a tertiary referral center throughout one decade. Methods: This retrospective study included patients with clinical diagnoses of band keratopathy who were treated with combined ethylenediaminetetraacetic acid (EDTA) and superficial keratectomy with or without amniotic membrane transplantation (AMT). Patient medical records were reviewed, and detailed demographic and ophthalmological data, such as baseline and last follow-up best-corrected distance visual acuity (BCDVA), ocular or medical comorbidities, type of intervention, postoperative follow-up duration, relevant complications, and recurrence were recorded. Results: A total of 32 eyes of 29 patients with 3 (10.3%) bilateral and 26 (89.7%) unilateral cases of treatment-requiring bank keratopathy were included. The mean (standard deviation [SD]) (range) age was 39.4 (22.4) (2–74) years, and most patients were female. The most common secondary cause was previous vitreoretinal surgery with silicone oil tamponade (15.6%); however, idiopathic cases were the most common (18.8%). Systemic comorbidities were present in 27.6% of patients, consisting of hypertension, diabetes mellitus, epilepsy, coronary artery disease, Behcet’s disease, and juvenile idiopathic arthritis; however, none of the patients had systemic diseases associated with hypercalcemia. Two of the 3 patients with bilateral involvement had chronic uveitis secondary to systemic rheumatological disease. The mean (SD) follow-up duration was 5.6 (4.0) years, and no serious postoperative complications occurred. The mean (SD) baseline and final BCDVA in logarithm of the minimum angle of resolution (logMAR) were 1.98 (1.0) and 1.7 (1.0), respectively (P > 0.05). Combined EDTA chelation and superficial keratectomy with and without AMT were performed in 12.5% and 87.5% of eyes, respectively. Recurrence was observed in 37.5% of eyes within the mean (SD) (range) follow-up of 9.4 (9.1) (1–32) months. Seven of the 12 eyes with recurrence underwent re-EDTA chelation combined with superficial keratectomy and AMT; however, 5 patients managed conservatively. Conclusions: In this study, band keratopathy requiring intervention more commonly affected female individuals and was unilateral. Most cases were idiopathic. Systemic comorbidities were present in approximately one-third of cases. Managing band keratopathy using a combination of EDTA chelation and superficial keratectomy with or without AMT could be a potential treatment modality. Further large-scale studies are required to provide robust conclusions regarding the efficacy and safety of this management approach.

Unveiling the Nanoscale Dielectric Gap and Its Influence on Ferroelectric Polarization Switching in Scanning Probe Microscopy

AbstractThe dielectric gap between the scanning probe microscopy (SPM) tip and the surface of a ferroelectric using conductive atomic force microscopy and piezoresponse force microscopy (PFM) is investigated. While the gap functions as a dielectric layer, it also allows tunneling current to inject charges into the ferroelectric when a critical loading force between 10–20 µN is applied to a tip with a radius of 25 nm under a bias voltage of 0.5 V. It is observed that the permittivity of the dielectric gap determines the coercive voltage measured by the piezoresponse hysteresis loop. While such studies done in air often produce coercive voltages much larger than those studied for the same materials in capacitor‐based studies, the use of high permittivity media such as water (ɛr = 79) or silicone oil (ɛr = 2.1‐2.8) produces coercive fields that more closely match those measured in conventional capacitor‐based polarization hysteresis loop measurements. Furthermore, using water as a dielectric medium in PFM imaging enhances the accuracy in extracting the amplitude and phase data from periodically poled lithium niobate crystals. These findings provide insight into the nanoscale phenomena of polarization switching instigated by the SPM tip and provide a pathway to improved quantitative studies.

Fabrication of multifunctional hybrid pigment for color cosmetics based on chitosan-modified palygorskite and sappanwood extract

Consumer perception and market demand have driven the replacement of synthetic colorants with naturally derived alternatives in the cosmetic industry. This study describes a facile way to prepare durable inorganic-organic hybrid pigment with advanced biocompatibility, antibacterial and hydrophobic properties tailored for color cosmetics by initial modification of palygorskite with chitosan to anchor sappanwood dye extract and subsequently coating with amino-modified silicone oil (ASO). The hybrid pigments were characterized by transmittance electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and the Brunauer–Emmett–Teller method. The results indicated that the sappanwood dye was loaded on chitosan-modified palygorskite via hydrogen bonding and electrostatic interaction. Furthermore, the chitosan-palygorskite/sappanwood hybrid pigment exhibited enhanced biocompatibility and color stability on exposure to different heating temperatures and UVA radiation after subsequent hydrophobic modification with amino-modified silicone oil. Moreover, facial foundation cosmetics based on the chitosan-palygorskite/sappanwood@ASO composites exhibited excellent brightening and skin color corrective effect on human volunteers without any adverse response. And no significant difference was observed in 12 out of 14 sensory evaluation indexes in the comparison of this hybrid pigment-based makeup with two commercially available products. This study provides a new route to stabilize natural botanical colorant for cosmetic use by chitosan-modified clay minerals.

Incidence of Akreos AO60 intraocular lens opacification after concurrent or subsequent intraocular oil or gas use.

To report the incidence of opacification in a consecutive series of 10 eyes that underwent scleral fixated Akreos AO60 placement with concurrent or subsequent contact with gas or silicone oil. Consecutive case series. Three cases of IOL opacification were noted. Two cases of opacification occurred in patients that underwent subsequent retinal detachment repair with C3F8 and one with silicone oil. One patient underwent explanation of the lens due to visually significant opacification. Scleral fixation of the Akreos AO60 IOL is associated with risk of IOL opacification when exposed to intraocular tamponade. While surgeons should consider the risk of opacification in patients at high risk of requiring intraocular tamponade, only 1 in 10 patients developed IOL opacification significant enough to require explantation.

Synthesis of amino silicone oil for use in oil agent in carbon fiber

Abstract An oil with uniform particle size distribution, good heat storage, and good wettability for carbon fiber was prepared. In other words, by mixing with non-ionic emulsifiers E1303 and E1309, the most suitable synthesis temperature, solid content, and the proportion of silicone oil emulsifiers were explored by using the control variable method. The results show that carbon fiber oil with uniform particle size distribution and good heat-resistant storage can be obtained when the synthesis temperature is 50°C, the solid content is 20% and the emulsifier ratio is 1:3. The particle size of the carbon fiber oil is 200 nm, the particle size distribution index is less than 0.3, and the particle size distribution is uniform.

Fabrication of superhydrophobic titanium surfaces: impact of different micropatterns

ABSTRACT Offshore and nuclear power plants use titanium condensers to cool exhaust steam from turbines. Preparation of robust superhydrophobic Titanium surfaces is necessary to protect these condensers from fouling and pitting phenomena. This study investigates the impact of various laser-textured Titanium grade 2 surface configurations followed by silicone oil heat treatment on enhancing its wettability and tribological properties. Seven distinct micropatterns were fabricated using a fiber laser with a laser power of 7.5 W, a scanning speed of 300 mm/s, a scan loop of 10, and a pulse frequency of 20 kHz. Patterned surfaces were characterized using different techniques, namely, micro-hardness, surface morphology, wettability, elemental analysis and wear. Improvement in wetting property was observed in laser textured samples after heating with silicone oil due to the adsorption of nonpolar groups (C=O, –CH3) resulting in a low energy surface. The grid pattern surface exhibited the highest water contact angle (WCA) of 151.01° due to a dense microstructure.

Shadowgraph Measurements of Rotating Convective Planetary Core‐Style Flows

AbstractThe local scale of rotating convection, ℓ, is a fundamental parameter in many turbulent geophysical and astrophysical fluid systems, yet it is often poorly constrained. Here we conduct rotating convection laboratory experiments analogous to convecting flows in planetary cores and subsurface oceans to obtain measurements of the local scales of motion. Utilizing silicone oil as the working fluid, we employ shadowgraph imagery to visualize the flow, from which we extract values of the characteristic cross‐axial scale of convective columns and plumes. These measurements are compared to the theoretical values of the critical onset length scale, ℓcrit, and the turbulent length scale, ℓturb. Our experimentally obtained length scale measurements simultaneously agree with both the onset and turbulent scale predictions across three orders of magnitude in convective supercriticality , a correlation that is consistent with inferences made in prior studies. We further explore the nature of this correlation and its implications for geophysical and astrophysical systems.

Intravitreal Silicone Oil with a Silicone-free versus a Siliconized Syringe

Intravitreal Silicone Oil with a Silicone-free versus a Siliconized Syringe

SURGICAL OUTCOMES OF RETINAL DETACHMENT ASSOCIATED WITH PROLIFERATIVE SICKLE CELL RETINOPATHY.

To evaluate the long-term anatomic and visual outcomes in eyes with sickle cell retinopathy-related retinal detachments (RDs). Patients who underwent surgery for sickle cell retinopathy-related RDs at the Wilmer Eye Institute or Wills Eye Hospital between 2008 and 2020 and followed for at least 6 months postoperatively were retrospectively reviewed. The primary outcome was the rate of single-surgery anatomic success and final reattachment. This study included 30 eyes from 28 patients (16 women and 12 men) with tractional RD (n = 13), rhegmatogenous RD (n = 1), and combined tractional RD/rhegmatogenous RD (n = 16). Mean age was 42.1 ± 15.1 years. The mean follow-up duration was 47.8 ± 34.1 months. Twenty-five (83.3%) eyes underwent pars plana vitrectomy and five (16.7%) eyes underwent pars plana vitrectomy with scleral buckling. Single-surgery anatomic success was achieved in 21 (70.0%) eyes at 6 months. Final reattachment was achieved in 28 (93.3%) eyes (22 eyes [73.3%] without tamponade). Recurrence of RDs was significantly associated with male gender (P = 0.041), absence of previous laser (P = 0.032), iatrogenic breaks (P = 0.035), retinectomy (P = 0.034), and silicone oil tamponade (P = 0.024). Overall, the logarithm of the minimum angle of resolution visual acuity improved from 1.53 ± 0.57 (Snellen equivalent, 20/678) to 1.15 ± 1.01 (20/283) at the final visit (P = 0.03); however, eyes with recurrent RD did not achieve significant visual improvement. Pars plana vitrectomy to repair sickle cell retinopathy-related RDs was effective in achieving anatomic success and improving vision in most eyes. Single-surgery anatomic success is critical for optimizing visual outcomes.

Enhanced propagation of free films with fast spread-out phenomena under the influence of megahertz surface acoustic waves

In this study, a novel approach for enhancing the rapid spreading of free liquid film on lithium niobate (LiNbO3) substrate under megahertz (MHz) surface acoustic wave (SAW) excitation is presented by treating it with surfactants. Through the design of a specific interdigital transducer structure, it was discovered that exciting the SAW at a frequency of 32.3 MHz can achieve optimal spreading performance for water droplets on the surface of surfactant-treated LiNbO3 substrate. The maximum average velocity reaches 1.76 mm/s at position P2 = 1250 μm in the water film front, and the stable film spreading speed shows a 204.9% increase compared to the existing research. Simultaneously, through the investigation of the spreading experiment phenomenon of silicone oil and de-ionized water droplets at varying frequencies, we have discovered the dynamic mechanism of “reverse phase” propagation in liquid film for the first time. This entails that the advancing edge of the wetting film demonstrates a spreading motion law that is opposite to the traditional spreading phenomena, with the spreading velocity in the central exceeding that on both sides. Our research demonstrates that this microfluidic device developed by SAWs enhances the spreading efficiency of the free films, enabling rapid expansion of the target liquid to form a high-surface area film layer. This advancement holds promise for overcoming the limitations of low sensitivity and short response time in the field of rapid pathological diagnosis in contemporary medicine.

[formula omitted]OWCh: Optimally Windowed Chirp rheometry using combined motor transducer/single head rheometers

Recent advances in rheometry exploiting frequency-modulated (chirp) waveforms have dramatically reduced the time required to perform linear viscoelastic characterisation of complex materials. However, the technique was optimised for ‘separate motor transducer’ instruments, in which the drive motor imposing the strain deformation is decoupled from the torque transducer. Whilst the use of optimised windowed chirps (OWCh) using other rheometers has been recently reported in the literature, no systematic study concerning the use of ‘combined motor transducer’ instruments (in which the motor and transducer subsystems are integrated into a single ‘head’) has been undertaken. In the present study, we demonstrate the use of OWCh rheometry using combined motor transducer/single-head rheometers using a stress-controlled operating principle, thus avoiding the reliance on complicated and instrument-specific feedback control systems that would be required to perform strain-controlled experiments. The use of stress-controlled chirps requires a modification to the established OWCh analysis protocol such that the complex viscosity η∗(ω) is used as an intermediate proxy function for ultimately computing the complex modulus G∗(ω). This approach negates the effect of the strain offset that is inherent to stress-controlled oscillatory rheometry. Secondly, a correction algorithm and operational criteria for identifying inertial artefacts is established before we consider the impact of chirp digitisation on data acquisition. The use of stress-controlled OWCh rheometry (which we term Stress-OWCh, i.e. σOWCh) is demonstrated for a diverse range of material classes including, Newtonian calibration fluids (silicone oil), polymer solutions (polyethylene oxide in water), an entangled polymer melt (polydimethylsiloxane), worm-like micellar systems (cetylpyridinium chloride/sodium salicylate), time-evolving critical gels (gelatin) and aging elastoviscoplastic materials (Laponite®). This novel implementation of chirp waveforms using a single-head rheometer will facilitate the wider adoption of OWCh rheometry and allow the benefits of frequency-modulation techniques to be exploited where separate motor transducer instruments are unavailable/unsuitable.

Dielectric anomalies and dc-resistivity degradation in PbNb2O6-based ceramics at high temperature

The lead metaniobate (PbNb2O6, PN) with high Curie temperature is widely used to fabricate transducer for high-temperature application up to 300 °C. However, evident dielectric anomalies and direct-current resistivity degradation were experimentally observed in PN-based ceramics at high temperature, which may significantly restrict the working temperature range for well logging application. When the sample was heat-treated at 260 °C for 3 h in silicon oil, the dc-resistivity of ceramics at 260 °C decreased from 3.8 × 108 to 1.0×107 Ω⋅cm, accompanied by 43 times increase in tanδ at 1 kHz. To investigate the cause of these phenomena, the in-situ piezoelectric, dielectric properties and dc-resistivity were systematically investigated in the samples subjected to heat-treatment at 260 °C in silicon oil. It is revealed that the porous structure of PN-based ceramics allows for the infiltration of silicon oil as a minor phase, and the accumulation of its decomposers within the pores would exert significant influence on the dielectric property and dc-resistivity of ceramics at elevated temperatures. However, the samples still demonstrate excellent thermal stability in piezoelectric property, with value of kt maintaining 0.39 at 260 °C in oil. In addition, the low Qm is not the intrinsic property of PN ceramics, but rather related to the phase transition of silicon oil within pores of ceramics, as indicated by the increase in Qm from 47 to 80 after heat-treatment in air.

Surgical Outcomes of Rhegmatogenous Retinal Detachment Associated with Regressed Retinopathy of Prematurity.

To evaluate the characteristics and surgical outcomes of late-onset rhegmatogenous retinal detachment (RRD) associated with regressed retinopathy of prematurity (ROP) and the status of fellow eyes. Retrospective review of consecutive cases undergoing surgery for regressed ROP-related RRD and the fellow eyes between 2012-2022. Demographic data, fundus findings, retinal detachment characteristics, surgical procedures, and anatomic and functional outcomes were analyzed. Anatomic success was defined as retinal attachment after silicone oil removal at final follow-up. Fifteen eyes of 14 patients with a history of regressed ROP underwent surgical repair for RRD at a mean age of 12 (range, 3-26) years. Primary surgical intervention yielded a 53% failure rate overall. This rate was 33% for scleral buckling (SB), 100% for pars plana vitrectomy (PPV), and 40% for combined SB-PPV surgery. Eyes with posterior cicatricial changes and/or proliferative vitreoretinopathy (PVR) demonstrated a higher tendency for recurrence. The final anatomic success rate was 73% after a mean number of 2.3 (range, 1-5) surgeries. The chances of restoring useful vision diminished with repeated surgery despite the improvement in anatomic success. In the fellow eyes, peripheral retinal pathologies were universally observed, with posterior cicatricial changes noted in 33%. The study reveals a significant initial failure rate in surgical treatment of cases with late-onset RRD associated with regressed ROP, particularly in eyes with posterior cicatricial changes or PVR, suggesting the need for a combined surgical approach as an initial strategy in such high-risk cases. The consistent presence of retinal abnormalities in fellow eyes calls for proactive monitoring and potential prophylactic intervention.