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Many modern anti-icing and anti-fouling coatings rely on soft, low surface energy elastomeric materials such as polydimethylsiloxane for their functionality. While the low surface energy is desirable for reducing adhesion, very little work considers the larger contribution to adhesive failure caused by the viscoelastic nature of elastomers. Here we examine several different siloxane elastomers using a JKR adhesion test, which was operated over a range of different speeds and temperatures. Additionally, we characterize the dynamic mechanical modulus over a large range of frequencies for each material. We note that surface energies of the materials are all similar, but variation in adhesion strength is clear in the data. The variation at low speeds is related to elastomer architecture but the speed dependence itself is independent of architecture. Qualitative correlations are noted between the JKR adhesion measurements and the dynamic moduli. Finally, an attempt is made to directly compare moduli and adhesion through the recent Persson–Brener model. Approximations of the model are shown to be inaccurate. The full model is found to be accurate at low speeds, although it fails to precisely capture higher speed behaviour. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the in vitro accuracy of impressions obtained with two silicone and corresponding stone models using two laboratory scanners. Materials and Methods: A master model with synthe:c resin teeth with two single-unit crown prepara:ons was created and scanned using a 12-megapixel scanner. Five conven:onal impressions of the physical model were prepared with different silicone impression systems (Zhermack and Coltene) using the double-mix technique and poured with gypsum. The impressions and stone models obtained were scanned using two extraoral scanning systems (Iden:ca T500, Medit; S600 ARTI, Zirkonzahn). All best-fit superimposi:ons of the teeth areas were conducted between the master model and the scans of the impressions and models obtained with the two scanners. A P < .05 level was considered significant. Results: The Iden:ca T500 Medit scanner showed an accuracy of 102.34 (89.67, 115.01) µm for Coltene silicone and 79.51 (67.82, 91.21) µm for Zhermack silicone, while the S600 ARTI Zirkonzhan scanner presented 110.79 (98.24, 123.33) µm and 91.91 (81.29, 102.54) µm, respec:vely, with significant differences between scanners for Zhermack silicone (P = .008) and for the corresponding stone models (P = .002). Zhermack silicone presented overall discrepancies lower than Coltene silicone, with sta:s:cally significant differences in both scanners analyzed (P < .001; P = .017). However, the discrepancies found were within clinically acceptable values. With the Zirkonzahn scanner, discrepancies found in the Zhermack impressions were lower than in the corresponding stone models (P < .001). Conclusions: The direct digi:za:on of silicone impressions with laboratory scanners presented comparable results to conven:onal techniques with stone models. [ABSTRACT FROM AUTHOR]

BackgroundDifferential risks for adverse pregnancy outcomes may be influenced by prenatal chemical exposures, but current exposure methods may not fully capture data to identify harms and differences.MethodsWe collected maternal and cord sera from pregnant people in Fresno and San Francisco, and screened for over 2420 chemicals using LC-QTOF/MS. We matched San Francisco participants to Fresno participants (N = 150) and compared detection frequencies. Twenty-six Fresno participants wore silicone wristbands evaluated for over 1500 chemicals using quantitative chemical analysis. We assessed whether living in tracts with higher levels of pollution according to CalEnviroScreen correlated with higher numbers of chemicals detected in sera.ResultsWe detected 2167 suspect chemical features across maternal and cord sera. The number of suspect chemical features was not different by city, but a higher number of suspect chemicals in cosmetics or fragrances was detected in the Fresno versus San Francisco participants' sera. We also found high levels of chemicals used in fragrances measured in the silicone wristbands. Fresno participants living in tracts with higher pesticide scores had higher numbers of suspect pesticides in their sera.ConclusionsMultiple exposure-assessment approaches can identify exposure to many chemicals during pregnancy that have not been well-studied for health effects.

Additive manufacturing (AM) is a disruptive manufacturing process that gives designers freedom to create highly complex shapes through free-form fabrication. The majority of polymers used in extrusion AM are thermoplastics because they are easy to process in affordable machines. While there are a number of moderate modulus thermoplastics in regular use in AM, thermoplastics are known to weaken with increases in temperature or exposure to solvents and many commodity thermoplastics used in AM are brittle. On the other hand, there are few elastomers, and even fewer elastomer reinforcement schemes, that are accessible using standard AM technologies. In this work, we report a novel dual extrusion process that integrates elastomeric silicone with reinforcing thermoplastic. By developing and demonstrating a dual extrusion 3D printer that can process common thermoplastics with commercially available thermosetting silicones, new types of composite elastomers are reported with good mechanical performance. The 0[degrees]/20[degrees]/-20[degrees] grid pattern thermoplastic reinforced samples achieved 2.5 MPa tensile strength in low extension region (0.5 strain), which improves the initial stiffness of the composite component. Desired mechanical responses of composite structures can be realized by tuning the reinforcement volume ratio and infill percentages, and applying various types of reinforcement mesh patterns and thermoplastics. Highlights * A dual extrusion process integrates fus filament fabrication and direct ink writing technologies. * Thermoplastic reinforced silicone composite with stiff/soft properties. * Tunable volume ratio, infill percentage, mesh pattern, and material option. KEYWORDS material characterization, material extrusion, thermoplastic composites additive manufacturing, thermoset composites, 1 | INTRODUCTION Additive manufacturing (AM) is the process of depositing material in a layer-by-layer manner through computer control such that the part produced has a three-dimensional structure built from [...]

Background: A common complication of bicanalicular intubation is dislocation of the silicone tube. Methods: Eleven patients with prolapsed silicone tubes who had undergone bicanalicular nasal intubation were injected with a 2 per cent lidocaine solution to infiltrate the lacrimal duct mucosa. A memory wire probe was used to pull a 4-0 suture through the lacrimal passage retrogradely, allowing the suture to grab the silicone tube. Paraffin oil was applied to the contact part of the rope and the silicone tube, then the distal end of the silk thread was removed from the nostril until the tube was pulled into place. Results: The prolapsed silicone tubes were restored by surgery in nine patients, with the drainage tube in the correct position in the eye and the lacrimal duct irrigation unobstructed. Conclusion: The optimisations made in this study are considered effective adjustments of reduction surgery for a prolapsed silicone tube. [ABSTRACT FROM AUTHOR]

Silicone oil is a commonly used lubricant in pre-filled syringes (PFSs) and can migrate over time into solution in the form of silicone oil particles (SiOPs). The presence of these SiOPs can result in elevated subvisible particle counts in PFS drug products compared to other drug presentations such as vials or cartridges. Their presence in products presents analytical challenges as they complicate quantitation and characterization of other types of subvisible particles in solution. Previous studies have suggested that they can potentially act as adjuvant resulting in potential safety risks for patients. In this paper we present several analytical case studies describing the impact of the presence of SiOPs in biotherapeutics on the analysis of the drug as well as clinical case studies examining the effect of SiOPs on patient safety. The analytical case studies demonstrate that orthogonal techniques, especially flow imaging, can help differentiate SiOPs from other types of particulate matter. The clinical case studies showed no difference in the observed patient safety profile across multiple drugs, patient populations, and routes of administration, indicating that the presence of SiOPs does not impact patient safety. [ABSTRACT FROM AUTHOR]

[Display omitted] A high-temperature-resistance insulating layer with high thermal conductivity is the key component for fabricating the instant metal-based electric heating tube. However, it is still a challenge for materials to possess excellent high-temperature resistance, superior insulating property, and high thermal conductivity at the same time. Here, a novel SiO 2 bridged AlN/MSR composite based on methylphenyl silicone resin (MSR) and AlN filler was reported. MSR with a high thermal decomposition temperature of 452.0 °C and a high withstand voltage of 5.6 kV was first synthesized by adjusting the contents of alkyl and phenyl groups. The superior high-temperature resistant insulating property is 3.7 and 2.4 times higher than the national standard requirement of 1.5 kV and commercial silicone resin, respectively. The hydrogen bonds formed between SiO 2 , AlN, and MSR and the electrostatic adsorption between SiO 2 and AlN can remarkably improve the uniform dispersion of AlN in MSR and thus enhance the insulating property, thermal conductivity, and thermal stability. With the addition of 2 wt% SiO 2 and 50 wt% AlN, the SiO 2 -AlN/MSR composite exhibits an extremely high withstand voltage of 7.3 kV, a high thermal conductivity of 0.553 W·m−1·K−1, and an enhanced decomposition temperature of 475 °C. The superior insulating property and thermal conductivity are 4.9 and 1.3 times higher than the national standard requirement and pure MSR, respectively. This novel composite shows great potential for application in the fields requiring integrated superior insulating property, high-temperature resistance, and high thermal conductivity. [ABSTRACT FROM AUTHOR]

We report the synthesis and single-crystal X-ray diffraction, magnetic, and luminescence measurements of a novel family of luminescent cage-like tetranuclear silsesquioxanes (PhSiO15)8(LnO15)4(O)(C5H8O2)6(EtOH)2(CH3CN)2-2CH3CN (where Ln = Tb, 1; Tb/Eu, 2; and Gd, 3), featuring seven-coordinated lanthanide ions arranged in a one-capped trigonal prism geometry. Compounds 1 and 2 exhibit characteristic Tb[sup 3+] and Tb[sup 3+]/Eu[sup 3+]-related emissions, respectively, sensitized by the chelating antenna acetylacetonate (acac) ligands upon excitation in the UV and visible spectral regions. Compound 3 is used to assess the energies of the triplet states of the acac ligand. For compound 1, theoretical calculations on the intramolecular energy transfer and multiphonon rates indicate a thermal balance between the [sup 5]D4 Stark components, while the mixed Tb[sup 3+]/Eu[sup 3+] analog 2, with a Tb:Eu ratio of 3:1, showcases intra-cluster Tb[sup 3+]-to-Eu[sup 3+] energy transfer, calculated theoretically as a function of temperature. By utilizing the intensity ratio between the [sup 5]D4^[sup 7]F5 (Tb[sup 3+]) and [sup 5]D0^[sup 7]F2 (Eu[sup 3+]) transitions in the range 11-373 K, we demonstrate the realization of a ratiometric luminescent thermometer with compound 2, operating in the range 11-373 K with a maximum relative sensitivity of 2.0% K[sup -1] at 373 K. These findings highlight the potential of cage-like silsesquioxanes as versatile materials for optical sensing-enabled applications. [ABSTRACT FROM AUTHOR]

Current research on materials engineering focuses mainly on bio-based materials. One of the most frequently studied materials in this group is polylactide (PLA), which is a polymer derived from starch. PLA does not have a negative impact on the natural environment and additionally, it possesses properties comparable to those of industrial polymers. The aim of the work was to investigate the potential of organosilicon compounds as modifiers of the mechanical and rheological properties of PLA, as well as to develop a new method for conducting mechanical property tests through innovative high-throughput technologies. Precise dosing methods were utilized to create PLA/silicone polymer blends with varying mass contents, allowing for continuous characterization of the produced blends. To automate bending tests and achieve comprehensive characterization of the blends, a self-created workstation setup has been used. The tensile properties of selected blend compositions were tested, and their ability to withstand dynamic loads was studied. The blends were characterized through various methods, including rheological (MFI), X-ray (XRD), spectroscopic (FTIR), and thermal properties analysis (TG, DSC, HDT), and they were evaluated using microscopic methods (MO, SEM) to examine their structures. [ABSTRACT FROM AUTHOR]

Microcellulose materials are increasingly considered multifunctional candidates for emerging energy applications. Microcellulose fibers (MCF) are a kind of bio-based reinforcement in composites, and their hydrophilic character hinders their wide application in industry. Thus, in the present work, MCF was hybrid-modified by amino silicone oil-phosphorylated to fabricate hydrophobic, thermal stability, and flame-retardant microcellulose fibers for potential application in vehicle engineering. The results showed that the amino silicone oil-phosphorylated (ASOP) hybrid modification could transform the surface property of microcellulose from hydrophilic to hydrophobic and improve the compatibility between MCF and resin matrix. Meanwhile, the ASOP treatment led to the formation of an amino silicone oil film layer on the surface of the microcellulose, which improved the thermal stability of the MCF. Furthermore, the ASOP hybrid modification microcellulose fibers paper (100% microcellulose fibers paper) was transformed from flammable to flame-retardant and showed self-extinguishing behavior after burning under flame for 2 s. The flame-retardant mechanism was attributed to the formation of the char layer in the condensed phase and the production of non-combustible gases in the gaseous phase. [ABSTRACT FROM AUTHOR]

Background: Endotamponade of the vitreous body with silicone oil is a common procedure, being the basis of many vitreoretinal surgeries. However, emulsification may happen, which is a clinically relevant adverse event of silicone oil use. Methods: This review provides a thorough analysis of the emulsification process. It focuses on describing factors affecting this event as well as its possible subsequent complications. Results: The viscosity of silicone oil, the duration of emulsification, the status of the lens and many other factors have an influence on the onset and intensity of emulsification. This phenomenon carries several risks for operated eyes such as increased intraocular pressure, keratopathy or structural changes to the retina. Conclusions: The use of modern imaging techniques, especially optical coherence tomography, enables faster detection of the emulsification process. This allows for an adequate clinical response and more accurate follow-up of the patient. [ABSTRACT FROM AUTHOR]

The electro-optical properties of methyl silicone oils with viscosities ranging from 10 to 10,000 cSt have been studied extensively to verify their suitability as immersion liquids. Immersion liquids are often used in nonlinear optics to protect hygroscopic crystals from moisture, reduce multiple reflections, and protect against electrical breakdown. However, the lack of experimental data makes it difficult to select an optimal liquid that does not exhibit a significant electro-optical Kerr effect in the fringing electric field around the electrodes on the crystal. Electro-optical measurements were performed using an improved dynamic polarimetric method, which compensates for the measurement errors caused by inaccurate positioning of the electro-optical modulator's operating point on its transmission characteristics. The values of the Kerr coefficient ranged from −8.83 × 10−16 to −6.79 × 10−16 m V−2 for all oil samples, at temperatures from 25 to 80 °C and frequencies from 67 to 1017 Hz. These exceptionally low values, together with a low dielectric constant, very good transparency, and high chemical stability, make methyl silicone oils highly suitable as immersion liquids. The Kerr coefficient and other electro-optical coefficients increased with increasing temperature. This unusual result cannot be adequately explained by Buckingham's molecular theory of the Kerr effect. [ABSTRACT FROM AUTHOR]

Introduction: The study presents the design and manufacturing of a custom silicone distal cup, with a high spatial resolution, to fit inside the prosthetic liner for the treatment of irregular morphology at the distal residual limb of a patient with lower-limb amputation. This distal cup for the inside of the prosthetic liner has intricate interior features matching the shape of the distal residual limb to prevent localized high-pressure regions. Methods: High-resolution 3D optical scanning, computer-aided design (CAD), and material extrusion (MEX) process for additive manufacturing of molds are three key techniques for designing and manufacturing this custom distal cup. A three-part mold for molding the distal cup with matching features was designed by CAD and fabricated by MEX. The subject evaluated the distal cup by walking using the distal cup before wearing the prosthetic liner in the lower-limb prosthesis. Results: A custom silicone distal cup was fabricated using a 3D-printed mold and evaluated using a Prosthetic User's Survey. Based on the survey, the insert has an acceptable comfort, suspension requirement, and ease of use. Conclusions: The scan by high spatial resolution Space Spider optical scanner could capture detailed features of the distal residual limb. The resulting distal cup had the protrusion that functioned to separate the invaginations. The subject was satisfied with the distal cup based on the Prosthetic User's Survey. Clinical Relevance: The approach to fabricate the custom silicone distal cup using a high-resolution 3D optical scanner and a 3D-printed mold can be applied to fabricate the distal cup with intricate features for a patient with irregular morphology at the distal residual limbs. [ABSTRACT FROM AUTHOR]

Organocatalytic ring-opening polymerization (ROP) is a versatile method for synthesizing well-defined polymers with controlled molecular weights, dispersities, and nonlinear macromolecular architectures. Despite spectacular advances in organocatalytic ROP, precision synthesis of polysiloxanes remains challenging due to the mismatch in polarity between highly polar initiators and nonpolar monomers and polymers and the difficulty in suppressing the formation of scrambling products via transetherification reactions during ROP of cyclic siloxanes. Here, we describe a binary organocatalytic ROP (BOROP) of hexamethylcyclotrisiloxane (D3) employing organic bases as catalysts and (thio)ureas as cocatalysts. The BOROP of D3 using triazabicyclodecene (TBD) and (thio)ureas generates polydimethylsiloxanes (PDMSs) with narrow dispersity (Mw/Mn < 1.1). Despite the similar basicities of TBD and 1,8-bis(tetramethylguanidino)naphthalene (TMGN), which is known as a proton sponge, a unitary organocatalytic system using TMGN was inactive for the ROP of D3. When the TMGN was paired with acidic urea, the BOROP of D3 yielded PDMSs with narrow dispersity (Mw/Mn < 1.1). Data suggest that the synergetic effect of TMGN and urea is results in an unprecedented activation–deactivation equilibrium between dormant and propagating species. The benefits of the present BOROP system are demonstrated by the formation of PDMS elastomers with more uniform network structures that are highly stretchy and have excellent mechanical properties. Organocatalytic ring-opening polymerization (ROP) is a versatile method for synthesizing well-defined polymers, however, precision synthesis of polysiloxanes remains challenging due to a mismatch in polarity between initiators, monomers, and polymers and the formation of scrambling products. Here, the authors describe a binary organocatalytic ROP of hexamethylcyclotrisiloxane employing organic bases as catalysts and (thio)urea as cocatalysts, achieving solubilization of multifunctional silanol initiators and 90% monomer conversion. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effect of two coating materials, a silicone sealing gel and a polytetrafluoroethylene (PTFE) tape, on the screw preload and removal torque value (RTV) to develop strategies to prevent prosthetic screw loosening. We examined 45 complexes comprising an implant, abutment, and prosthetic screw, of which 15 samples were uncoated, 15 were coated with GapSeal® (Hager & Werken GmbH & Co., Duisburg, Germany), and 15 were coated with PTFE tape (MIARCO®, Valencia, Spain). The screws were tightened to register the preload and then untightened to register the RTV. The preload values showed a statistically significant difference only in the PTFE group, suggesting that this lubricant negatively affects the preload. The RTVs showed statistically significant differences among all groups, with the GapSeal® group and PTFE group showing the highest and lowest values, respectively. It can be concluded that the application of the PTFE tape on the screw significantly reduced the preload and RTV. The silicone sealing gel did not affect the preload but increased the RTV. Therefore, the use of GapSeal® should be considered to prevent prosthetic screw loosening, while the use of PTFE tape should be avoided. [ABSTRACT FROM AUTHOR]

This study analyzed the dentin shear bond strength (SBS) of an etch-and-rinse (ER) or a self-etch (SE) adhesive incorporated with multifunctional polyhedral oligomeric silsesquioxanes (MA-POSS-8). An ER adhesive (Solobond Plus, VOCO GmbH, Cuxhaven, Germany) and a universal adhesive applied in SE mode (Scotchbond Universal, 3M, St. Paul, MN, USA) were infiltrated with MA-POSS-8 (Hybrid Plastics Inc., Hattiesburg, MS, USA) at 5 wt.% or 10 wt.%. Pure adhesives served as controls. Bovine dentin specimens were conditioned with one of the adhesives prior to the application of a nano-hybrid composite (Venus Diamond A3, Kulzer, Hanau, Germany). SBS and failure modes were determined after water storage for 24 h, 6 months, 12 months, or 24 months (each subgroup n = 20). Statistical analysis was performed using ANOVAs, Weibull statistics, and χ2 tests (p < 0.05). SBSs for the control groups after 24 h were 17.4 ± 4.9 MPa for the ER adhesive and 19.1 ± 5.2 MPa for the universal adhesive. After 24 months, the SBS of the ER adhesive was significantly higher for 5 wt.% MA-POSS-8 (17.9 ± 5.1 MPa) than for the control group (14.6 ± 3.6 MPa) and 10 wt.% MA-POSS-8 (12.8 ± 4.1 MPa), and more cohesive failures were observed. The SBS of the universal adhesive increased during aging, irrespective of the MA-POSS-8 concentration. 5 wt.% MA-POSS-8 improves the SBS of the ER adhesive and does not impair the SBS of the SE adhesive. [ABSTRACT FROM AUTHOR]

While smaller polyhedral oligomeric silsesquioxanes TnRn (POSS) are readily accessible or even commercially available, unambiguously authenticated larger systems (n>12) have barely been reported. Synthesis and isolation procedures are lengthy, and yields are often very low. Herein, we present the surprisingly straightforward and high‐yielding access to the phenyl‐substituted derivative of a so far only postulated second D3h‐symmetric T14 isomer and with that the largest crystallographically characterized POSS cage with organic substituents. Treatment of the commercially available incompletely condensed T7Ph7(OH)3 silsesquioxane with catalytic amounts of trifluoromethanesulfonic acid results in high yields of the T14Ph14 framework, which is isolated in crystalline form by a simple work‐up. D3h‐T14Ph14 was analyzed by single crystal X‐ray diffraction, multinuclear NMR spectroscopy and thermal analysis. The relative energies of all four theoretically possible T14Ph14 isomers were determined by optimization of the corresponding structure using DFT methods. [ABSTRACT FROM AUTHOR]

This article presents a series of experimental investigations on the viscoelastic behavior of silica-filled and silver-filled silicone rubber on the unaged and aged states. The study of specific aging conditions relative to the electronics industry is proposed in this work, namely aging in a hermetic, initially inert atmosphere, at high temperatures. Viscoelastic properties of the materials are measured through DMA tests. Strain sweep tests are carried for the characterization of unaged materials, and frequency sweeps at ambient temperature are performed to characterize the aging-dependent behavior. As a result of the experimental studies, an aging-dependent generalized Maxwell model is proposed in an attempt to describe the evolution in the behavior of silicones due to aging. [ABSTRACT FROM AUTHOR]

Open in new tab Download slide OBJECTIVES Many types of congenital heart disease are amenable to surgical repair or palliation. The procedures are often challenging and require specific surgical training, with limited real-life exposure and often costly simulation options. Our objective was to create realistic and affordable 3D simulation models of the heart and vessels to improve training. METHODS We created moulded vessel models using several materials, to identify the material that best replicated human vascular tissue. This material was then used to make more vessels to train residents in cannulation procedures. Magnetic resonance imaging views of a 23-month-old patient with double-outlet right ventricle were segmented using free open-source software. Re-usable moulds produced by 3D printing served to create a silicone model of the heart, with the same material as the vessels, which was used by a heart surgeon to simulate a Rastelli procedure. RESULTS The best material was a soft elastic silicone (Shore A hardness 8). Training on the vessel models decreased the residents' procedural time and improved their grades on a performance rating scale. The surgeon evaluated the moulded heart model as realistic and was able to perform the Rastelli procedure on it. Even if the valves were poorly represented, it was found to be useful for preintervention training. CONCLUSIONS By using free segmentation software, a relatively low-cost silicone and a technique based on re-usable moulds, the cost of obtaining heart models suitable for training in congenital heart defect surgery can be substantially decreased. [ABSTRACT FROM AUTHOR]

Cilia are biological structures essential to drive the mobility of secretions and maintain the proper function of the respiratory airways. However, this motile self-cleaning process is significantly compromised in the presence of silicone tracheal prosthesis, leading to biofilm growth and impeding effective treatment. To address this challenge and enhance the performance of these devices, we propose the fabrication of magnetic silicone cilia, with the prospect of their integration onto silicone prostheses. The present study presents a fabrication method based on magnetic self-assembly and assesses the interaction behavior of the cilia array with biological mucus. This protocol allows for the customization of cilia dimensions across a wide range of aspect ratios (from 6 to 85) and array densities (from 10 to 80 cilia/mm2) by adjusting the fabrication parameters, offering flexibility for adjustments according to their required characteristics. Furthermore, we evaluated the suitability of different cilia arrays for biomedical applications by analyzing their interaction with bullfrog mucus, simulating the airways environment. Our findings demonstrate that the fabricated cilia are mechanically resistant to the viscous fluid and still exhibit controlled movement under the influence of an external moving magnet. A correlation between cilia dimensions and mucus wettability profile suggests a potential role in facilitating mucus depuration, paving the way for further advancements aimed at enhancing the performance of silicone prostheses in clinical settings. [ABSTRACT FROM AUTHOR]

Age-related vessel deterioration leads to changes in the structure and function of the heart and blood vessels, notably stiffening of vessel walls, increasing the risk of developing cardiovascular disease (CVD), which accounts for 17.9 million global deaths annually. This study describes the fabrication of custom-made silicon vessels with varying mechanical properties (arterial stiffness). The primary objective of this study was to explore how changes in silicone formulations influenced vessel properties and their correlation with features extracted from signals obtained from photoplethysmography (PPG) reflectance sensors in an in vitro setting. Through alterations in the silicone formulations, it was found that it is possible to create elastomers exhibiting an elasticity range of 0.2 MPa to 1.22 MPa. It was observed that altering vessel elasticity significantly impacted PPG signal morphology, particularly reducing amplitude with increasing vessel stiffness (p < 0.001). A p-value of 5.176 × 10−15 and 1.831 × 10−14 was reported in the red and infrared signals, respectively. It has been concluded in this study that a femoral artery can be recreated using the silicone material, with the addition of a softener to achieve the required mechanical properties. This research lays the foundation for future studies to replicate healthy and unhealthy vascular systems. Additional pathologies can be introduced by carefully adjusting the elastomer materials or incorporating geometrical features consistent with various CVDs. [ABSTRACT FROM AUTHOR]

Background: Critically ill patients are more vulnerable to medical adhesive‐related skin injuries (MARSI), whose prevention is a constant challenge and one of the main quality indicators of nursing care. MARSI associated with indwelling urinary catheter (IUC) fixation is a relevant adverse event, mainly because of the constant involuntary traction and high skin vulnerability of the fixation site. Silicone adhesive tape has appreciable qualities for fragile skin among the range of adhesives, leading to the inference that it reduces the risk of MARSI. Aim: To compare silicone adhesive tape for IUC fixation with acrylate tape regarding its safety and efficacy. Study Design: This was a randomized controlled trial blinded to the patients and evaluator. Data were collected from an intensive care unit (ICU) of a tertiary university hospital in Brazil. Patients with IUC and no MARSI at the fixation site were considered eligible. The omega (Ω) fixation technique was used for IUC fixation. A total of 132 participants were enrolled and divided into two research groups: 66 patients in the intervention group (silicone tape) and 66 in the control group (acrylate tape). Outcomes were the incidence of MARSI, patient outcome in the ICU and hospital and partial, total and overall spontaneous detachment of the tapes. Results: The overall incidence of MARSI was 28%, with 21% in the silicone group and 35% in the acrylate group, with no statistically significant difference (p =.121), including the severity of the lesions (p =.902). However, partial (p =.003) and overall (p <.001) detachment of the tapes were more frequent in the silicone group. Conclusions: Silicone tape is no safer than acrylate tape for IUC fixation and is less adhesively effective. Relevance to Clinical Practice: There is no evidence to support the extensive use of silicone tape in this context. [ABSTRACT FROM AUTHOR]

Increasing demand for fully recyclable polymers has prompted an interest in materials crosslinked via non-covalent interactions. Aggressive depolymerization can cleave backbone SiO bonds to generate linear oils or cyclic monomers from silicone rubbers, but one would rather recover the starting material oils simply by selectively breaking crosslinks. We demonstrate that ligand binding to metals can be used to reversibly crosslink silicone chains. Aminopropylsilicones were crosslinked via complexation with copper (II) acetate to form blue silicone oils. These oils slowly cured in air at room temperature to form soft, green elastomers over a month, or overnight at 50–55 °C in air to give robust, hard red elastomers. Potential explanations for the observed color changes are discussed. Elastomers prepared by either pathway underwent ready degradation by removal of the copper ions via competitive ligand binding using ethylenediamine, allowing for recovery of the unmodified silicone oil; the recovered amine could be reused with more copper to form a (softer) elastomer. This process provides a method for the synthesis of stable elastomeric silicones that are degradable on demand. [ABSTRACT FROM AUTHOR]

Incorporation of siloxane-functionalized units into polymers backbone has proven to be an efficient strategy to improve photovoltaic performance. In this work, a low-cost siloxane-containing unit was developed to construct a series of terpolymers, and the effects of siloxane on the polymer performance were systematically studied. Different contents of thiophene containing siloxane-functionalized side chain were introduced into PM6 to obtain a series of polymers (PM6, PM6-SiO-10, PM6-SiO-20 and PM6-SiO-30). The siloxane-functionalized side chains in polymers have only a slight effect on the absorption behavior and frontier molecular orbitals. However, when the siloxane content increased, the terpolymers' aggregation property decreased and the temperature-dependency increased, leading to improved donor-acceptor compatibility. The power conversion efficiency (PCE) based on PM6:Y6, PM6-SiO-20:Y6 and PM6-SiO-30:Y6 devices was 15.64%, 16.03% and 15.82%, respectively. In comparison, the active layer based on PM6-SiO-10:Y6 exhibits the most appropriate phase separation morphology, resulting in effective exciton dissociation, more balanced hole-electron transport and less recombination. Consequently, the highest PCE of 16.69% with an outstanding short-circuit current density of 26.96 mA·cm−2 was obtained, which are one of the highest values for siloxane-functionalized polymer-based devices. This work demonstrates that finely controlling the content of siloxane-functionalized thiophene is beneficial for obtaining high-performance terpolymer donors and provides a novel and low-cost method to improve photovoltaic performance. [ABSTRACT FROM AUTHOR]

Background: Trans-abdominal pre-peritoneal (TAPP) hernia repair is a complex procedure that presents several challenges. Even though, due to the high prevalence of inguinal hernia, TAPP technique is increasing in frequency and robotic Abdominal Wall Surgery (rAWS) is emerging as a valuable tool in this regard. Although inguinal TAPP procedure principles have been published and simulation is needed, the availability of validated models remains scarce. Methods: A new low-cost model was developed to simulate inguinal rTAPP repair. For validity assessment, a new TAPP-specific fidelity questionnaire and assessment scale were developed to compare the performance of novices and experts in the simulated procedure. The models used were assessed at 60 min for execution and quality score. Results: Twenty-five residents and specialists from all over the country participated in this study. Execution, quality, and global performance was higher in the seniors group compared to juniors (8.91 vs 6.36, p = 0.02; 8.09 vs 5.14, p <.001; and 17 vs. 11,5, p <.001, respectively). Overall fidelity was assessed as being very high [4.41 (3.5–5.0), α =.918] as well as face [4.31 (3.0–5.0), α =.867] and content validity [4.44 (3.2–5.0), α =.803]. Participants strongly agreed that the model is adequate to be used with the DaVinci® Robot [4.52 (3.5–5.0), α =.758]. Conclusion: This study shows face, content, and construct validity of the model for inguinal TAPP simulation, including for robotic surgery. Therefore, the model can be a valuable tool for learning, understanding, practicing, and mastering the TAPP technique prior to participating in the operating room. [ABSTRACT FROM AUTHOR]

Open-Label Extension (OLE) studies are important in the drug development process and are used to further support the licensing applications and regulatory approvals of products. We aimed to understand why women chose to join the HOPE OLE study – where women were offered the dapivirine vaginal ring after two pivotal trials were completed – through data collected from individual in-depth interviews. Ten women at each of the six HOPE research sites in Lilongwe, Malawi; Durban (2 sites) and Johannesburg, South Africa; Kampala, Uganda; and Chitungwiza, Zimbabwe, were enrolled (n = 60). Access to an effective user-initiated HIV prevention product was one of the main reasons women joined HOPE. Although many participants worried that their male partners might expose them to HIV, they chose to remain in their relationships and avoid conflict or confrontation with their partners by discreetly using the ring to protect themselves. Other reasons for joining were quality healthcare, reimbursement and altruism. Researchers should better understand social and personal motivators behind research participation in order to recognize community sociocultural norms and its influences on product acceptability and adherence challenges. [ABSTRACT FROM AUTHOR]

Purpose: To examine the role of the silicone stent in palliation of malignant central airway obstruction and identify potential preprocedural predictors for postprocedural outcome. Methods: Patients treated with endoscopic insertion of tracheobronchial silicone stents for malignant central airway obstruction at Aarhus University Hospital from 2012 to 2022 were identified from electronic medical records. Statistical analyses were carried out to identify factors affecting Days Alive and Out of Hospital, complications and overall survival. Results: 81 patients underwent a total of 90 tracheobronchial stent insertions. Days Alive and Out of Hospital (DAOH) for the first 30 days were affected negatively by urgent intervention, p < 0.001, preprocedural non-invasive respiratory support, p < 0.001, and preprocedural intubation, p = 0.02. Post-procedural oncological treatment was associated with a significant improved DAOH, p = 0.04. Symptomatology and lesion characteristics were not significantly associated with any impact on DAOH. Overall survival was poor (mean survival was 158 days), and only significantly affected by severe degree of dyspnea, p = 0.02, and postprocedural oncological treatment, p < 0.001. Complication where registered in 25.6% of cases within the first 30 days was observed. Procedure-related mortality was 3.7%. Based on chart annotations by an ENT-surgeon, 95% of the patients experienced relief of symptoms following stent insertion. Conclusions: Palliative tracheobronchial airway stenting with silicone stents is found to have a beneficial impact, more research is required for identification of predictors for postprocedural outcome based on preprocedural classifications. [ABSTRACT FROM AUTHOR]

Introduction: Body defects impact well-being, necessitating efficient prosthetic techniques. This report explores integrating CAD/CAM technology for auricular prostheses, emphasizing a digital approach. Material & Methods: The plan involved irreversible hydrocolloid impressions, generating a digital resin model through an indirect scanner. Traditional molding and 3D printing combined for pattern formation. The mold's investment, fabrication, and coloring used intrinsic and extrinsic painting. Results: CAD/CAM showcased enhanced compatibility and aesthetics. The digital resin model improved adaptability, streamlining production, and accelerating the wax try-in process. Patient satisfaction during follow-ups validated the prosthesis success. Conclusion: Exploring auricular prosthesis advancements via digital technology, particularly the digital resin model, demonstrated transformative outcomes. This approach not only enhances adaptability and aesthetics but also expedites production, promising a seamless and time-efficient restoration of ear aesthetics for individuals.

[Display omitted] Ranging from industrial facilities to residential infrastructure, functional surfaces encompassing functionalities such as anti-fouling, fog collection, anti-corrosion, and anti-icing play a critical role in the daily lives of humans, but creating these surfaces is elusive. Bionic dewetting and liquid-infused surfaces have inspired the exploitation of functional surfaces. However, practical applications of these existing surfaces remain challenging because of their inherent shortcomings. In this study, we propose a novel functional slippery lubricated coating (FSLC) based on a simple blend of polysilazane (PSZ), silicone oil, and nano silica. This simple, nonfluorine based, and low-cost protocol promotes not only hierarchical micro-nano structure but also favorable surface chemistry, which facilitates robust silicone oil adhesion and excellent slippery properties (sliding angle: ∼1.6°) on various solid materials without extra processing or redundant treatments. The highly integrated competence of FSLC, characterized by robustness, durability, strong adhesion to substrates, and the ability for large-area preparation, render them ideal for practical production and application. The proposed FSLC holds outstanding application potentials for anti-fouling, self-cleaning, fog collection, anti-corrosion, and anti-icing functionalities. [ABSTRACT FROM AUTHOR]

[Display omitted] • Developed an ultrahigh-strength silicone aerogel with an innovative armor-like epoxy framework using a temperature-controlled sequential reaction strategy. • Achieved superior mechanical properties in the aerogel with compressive modulus ranging from 37.8 to 244.3 MPa, significantly surpassing other polymer-reinforced silicone aerogels. • The aerogel demonstrates exceptional thermal insulation, maintaining a low thermal conductivity of 0.025 to 0.051 W m−1 K−1 and maintains thermal characteristics across a temperature range of −20 to 300 °C. • Enhanced aerogel composites exhibit significantly improved mechanical strength while maintain low thermal conductivities, further expanding their practical applications in various industries. Aerogels with low density and high porosity are extremely attractive for high-performance insulation, but their brittleness, complicated fabrication, and poor mechanical properties greatly limit their practical applications. Herein, we report an ultrahigh-strength silicone aerogel with an armor-like epoxy framework via a temperature-controlled sequential reaction strategy. The key to this synthesis is forming a Si-O-Si framework via the polycondensation of silanes at 100 °C, followed by in-situ armoring an epoxy framework via an intermolecular cyclization at an elevated temperature of 150 °C. Owing to the enhanced framework, the resulting aerogel could withstand capillary tension in the drying process, enabling it to be dried at ambient pressure without shrinkage. The obtained aerogel possesses a tunable density of 0.17–0.45 g/cm3 and ultrahigh-strength with compressive modulus up to 37.8–244.3 MPa, which surpasses other polymer-reinforced silicone aerogels by a factor of five in mechanical properties. It also demonstrates outstanding thermal insulation, with an extremely low thermal conductivity from 0.025 to 0.051 W m−1 K−1 at room temperature, and maintains thermal characteristics across a temperature range of −20 to 300 °C. Furthermore, the aerogel composites prepared by the reinforcement of low-density fiber mats have tunable densities of 0.36–0.87 g/cm3, much enhanced tensile strengths of 15.9–72.3 MPa, and low thermal conductivities at room temperature of 0.042–0.078 W m−1 K−1. This study presents a cost-effective method for enhancing the production of silicone aerogel materials, offering considerable opportunities for their application in insulation, energy transport, and the aerospace sector. [ABSTRACT FROM AUTHOR]

Recent advancements on electrohydrodynamic (EHD) soft pumps demonstrate their applicability to various fluid-driven systems such as soft robots, wearable devices, and stretchable electronics. In particular, fiber type EHD pumps reported more recently is a promising pumping element thanks to their versatile fibrous structure. Yet existing EHD fiber pumps are less stretchable and require sophisticated, complex fabrication equipment, implying opportunity for technology advancement. This paper presents a simplified method to create highly stretchable multifunctional fiber EHD pumps. The method employs highly compliant silicone elastomers for the fiber structure that is formed by simple dipping fabrication process. The fabricated pumps (length of 100 mm, inner diameter 4 mm, and mass 5.3 g) exhibit a high stretchability (up to 40% strain) and flow rate and pressure of 167.4 ± 7.6 mL/min (31.6 mL/min/g) and 4.1 ± 0.6 kPa (0.8 kPa/g), respectively. These performances are comparable or even higher than those of previously reported EHD pumps including fiber types. The output performance of the fabricated pumps remain constant for repeated strain cycles (0–25%, up to 2000 cycles) and bending angle up to 180° (corresponding to curvature of 0–30/m). Moreover, the pumps demonstrate unprecedented functionality as a sensor to distinguish the type of fluid inside the tube and to detect strains by reading the capacitance between the electrodes. The characterization result reveals the sensing ability of the pumps as high repeatability up to 30% strain with negligible hysteresis, which is consistent for 5000 cycles. [ABSTRACT FROM AUTHOR]

Organosilicon polymers (silicones) are of enduring interest both as an established branch of polymer chemistry and as a segment of commercial products. Their unique properties were exploited in a wide range of everyday applications. However, current silicone trends in chemistry and materials engineering are focused on new smart applications, including stretchable electronics, wearable stress sensors, protective coatings, and soft robotics. Such applications require a fresh approach to methods for increasing the durability and mechanical strength of polysiloxanes, including crosslinked systems. The introduction of self-healing options to silicones has been recognized as a promising alternative in this field, but only carefully designed multifunctional systems operating with several different self-healing mechanisms can truly address the demands placed on such valuable materials. In this review, we summarized the progress of research efforts dedicated to the synthesis and applications of self-healing hybrid materials through multi-component systems that enable the design of functional silicon-based polymers for smart applications. [ABSTRACT FROM AUTHOR]

Polysiloxane with multiple acryloxyl groups at the terminal site of the polymer chain was synthesized by the condensation reaction between hydroxyl-terminated polysiloxane and acryloyl chloride and used to improve the cross-linking density of UV-curable silicone materials initiated from dual acryloxy-terminated symmetric polysiloxane or single acryloxy-terminated asymmetric polysiloxane with the mixture of Irgacure 1173 and Irgacure 184 at a mass ratio of 1:1 as the photoinitiator. The effects of factors such as initiator composition, UV irradiation time, structure, and molecular weight of linear dual acryloxy-terminated or single acryloxy-terminated asymmetric siloxane oligomers on the gelation yield, thermal properties, water absorption, and water contact angle of UV-cured film were investigated. The synthesized cross-linking density modifier can be copolymerized with acryloxy-functionalized linear polysiloxanes under the action of a photoinitiator to increase the cross-link density of UV-cured products effectively. Both linear dual acryloxy-terminated or single acryloxy-terminated asymmetric siloxane oligomers can be copolymerized with cross-link density modifiers within 20 s of UV irradiation. The gelation yields of the UV-cured products obtained from the dual acryloxy-terminated siloxane oligomers were greater than 85%, and their surface water contact angles increased from 72.8° to 95.9° as the molecular weight of the oligomers increased. The gelation yields of UV-cured products obtained from single acryloxy-terminated asymmetric siloxane oligomers were less than 80%, and their thermal stabilities were inferior to those obtained from the dual acryloxy-terminated siloxane oligomers. However, the water contact angles of UV-cured products obtained from these single acryloxy-terminated asymmetric siloxane oligomers were all greater than 90°. [ABSTRACT FROM AUTHOR]

Embedded printing has emerged as a valuable tool for fabricating complex structures and microfluidic devices. Currently, an ample of amount of research is going on to develop new materials to advance its capabilities and increase its potential applications. Here, a novel, transparent, printable, photocrosslinkable, and tuneable silicone composite is demonstrated that can be utilized as a support bath or an extrudable ink for embedded printing. Its properties can be tuned to achieve ideal rheological properties, such as optimal self‐recovery and yield stress, for use in 3D printing. When used as a support bath, it facilitated the generation microfluidic devices with circular channels of diameter up to 30 µm. To demonstrate its utility, flow focusing microfluidic devices are fabricated for generation of Janus microrods, which can be easily modified for multitude of applications. When used as an extrudable ink, 3D printing of complex‐shaped constructs are achieved with integrated electronics, which greatly extends its potential applications toward soft robotics. Further, its biocompatibility is tested with multiple cell types to validate its applicability for tissue engineering. Altogether, this material offers a myriad of potential applications (i.e., soft robotics, microfluidics, bioprinting) by providing a facile approach to develop complicated 3D structures and interconnected channels. [ABSTRACT FROM AUTHOR]

In this research, a series of silicone foam/polytitanosiloxane composites (SF-pTS) were fabricated with hydroxy-, vinyl-, hydrogen-containing polydimethylsiloxanes, and polytitanosiloxane filler in the presence of a platinum catalyst under ambient conditions. The effect of the amount of polytitasiloxane on the micromorphology and flame retardancy of silicone foam was studied, and a relative flame retardancy mechanism was proposed. It could be found that the polytitanosiloxane exhibited a good dispersion level in the silicone foam, thus improving the flame retardancy of the composite. When the content of polytitanosiloxane is 9 wt%, the limiting oxygen index and UL-94 grade of the SF-pTS9 composite are increased to 29.2% and FV-0, respectively. Cone experiment results suggested that the SF-pTS9 possessed relative balanced PHRR (148.9 kW/m2), THR (58.5 MJ/m2), TSP (0.6 m2), and mass residue (83.9%) among the prepared silicone foam materials. This work provides a new avenue to fabricate a silicone foam composite with enhanced flame retardancy. [ABSTRACT FROM AUTHOR]

Treatment of long-segment tracheal defects remains a challenge in thoracic surgery with no standard surgical option. Aortic allografts have been used for this purpose with varying degrees of success. In a patient that suffered anastomotic dehiscence after tracheal resection with primary anastomosis, we performed complete tracheal resection and replacement using a stented circumferential aortic allograft. Currently, this patient is able to breathe normally without tracheostomy assistance 22 months postoperatively. Our report is the first in the English literature of long-term survival without tracheostomy dependence and close interval follow-up after circumferential tracheal resection and replacement with a cryopreserved aortic allograft. [ABSTRACT FROM AUTHOR]

Recycling of polyolefins has become a on-demand route to avoid its environmental threats. Nevertheless, drop of properties after re-extrusion necessitates use of reinforcing agents to compensate for poor mechanical properties. The incorporation of nanoparticles into plastics can boost their mechanical and rheological properties due to the hard nanocrystalline phases. This study aims to promote and identify a polyolefin-based nanocomposite by combination of TiO2 and polyhedral oligomeric silsesquioxane (POSS) at concentration of 1, 3, and 6 wt% in a twin-screw extruder. The nanocomposites were characterized for mechanical and rheological properties. Overall, the results showed that the mechanical properties were improved by adding particles up to 6 wt% loadings. The magnitude of this effect was dependent on the nanofiller weight fraction and particle size. Well-dispersion and, as a result, enhancing the viscosity, modulus, and hardness in the sample containing 3 wt% TiO2 and 3 wt%. POSS was due to the presence of hydroxyl functional groups on its surface. Glass transition temperature and crystallinity of the samples did not show a significant change due to the neutral role of nanoparticle nucleation in the matrix. [ABSTRACT FROM AUTHOR]

The first dedicated tracheobronchial silicone stent was designed by the French pulmonologist Jean‐Paul Dumon. The most common indications for stenting are to minimise extrinsic airway compression from mass effect, maintain airway patency due to intrinsic obstruction or treat significant nonmalignant airway narrowing or fistulae. Silicone stents require rigid bronchoscopy for insertion; however, they are more readily repositioned and removed compared with metallic stents. Metallic stents demonstrate luminal narrowing when loads are applied to their ends, therefore stents should either be reinforced at the ends or exceed the area of stenosis by a minimum of 5 mm. Nitinol, a nickel‐titanium metal alloy, is currently the preferred material used for airway stents. Airway stenting provides effective palliation for patients with severe symptomatic obstruction. Drug‐eluting and three‐dimensional printing of airway stents present promising solutions to the challenges of the physical and anatomical constraints of the tracheobronchial tree. Biodegradable stents could also be a solution for the treatment of nonmalignant airway obstruction. [ABSTRACT FROM AUTHOR]

While functioning in the oral cavity, denture soft linings (SL) are exposed to contact with the microbiota. Dentures can offer perfect conditions for the multiplication of pathogenic yeast-like fungi, resulting in rapid colonisation of the surface of the materials used. In vitro experiments have also shown that yeast may penetrate SL. This may lead to changes in their initially beneficial functional properties. The aim of this work was to investigate the effect of three months of exposure to a Candida albicans suspension on the mechanical properties of SL material and its bond strength to the denture base polymer, and to additionally verify previous reports of penetration using a different methodology. Specimens of the SL material used were incubated for 30, 60 and 90 days in a suspension of Candida albicans strain (ATCC 10231). Their shore A hardness, tensile strength, and bond strength to acrylic resin were tested. The colonization of the surface and penetration on fractured specimens were analysed with scanning electron and inverted fluorescence microscopes. Exposure to yeast did not affect the mechanical properties. The surfaces of the samples were colonised, especially in crystallized structures of the medium; however, the penetration of hyphae and blastospores into the material was not observed. [ABSTRACT FROM AUTHOR]

The article describes new silicone self-adhesive adhesives modified with the addition of talc. The obtained self-adhesive materials were characterized to determine their adhesive properties (adhesion, cohesion, and adhesion) and functional properties (pot life of the composition, shrinkage, and thermal properties of adhesives). Novel materials exhibited high thermal resistance above 225 °C while maintaining or slightly reducing other values (adhesion, cohesion, shrinkage, and tack). Selected composition: T 0.1 was used to prepare self-adhesives in industrial-scale production. Moreover, conducted test results revealed that the addition of talc delayed the thermal decomposition of the adhesive and provided reduced intensity of smoke emissions during combustion as well as the flammability of the adhesive layer. [ABSTRACT FROM AUTHOR]

Background: Artificial tendons may be an effective alternative to autologous and allogenic tendon grafts for repairing critically sized tendon defects. The goal of this study was to quantify the in vivo hindlimb biomechanics (ground contact pressure and sagittal-plane motion) during hopping gait of rabbits having a critically sized tendon defect of the tibialis cranialis and either with or without repair using an artificial tendon. Methods: In five rabbits, the tibialis cranialis tendon of the left hindlimb was surgically replaced with a polyester, silicone-coated artificial tendon (PET-SI); five operated control rabbits underwent complete surgical excision of the biological tibialis cranialis tendon in the left hindlimb with no replacement (TE). Results: At 8 weeks post-surgery, peak vertical ground contact force in the left hindlimb was statistically significantly less compared to baseline for the TE group (p = 0.0215). Statistical parametric mapping (SPM) analysis showed that, compared to baseline, the knee was significantly more extended during stance at 2 weeks post-surgery and during the swing phase of stride at 2 and 8 weeks post-surgery for the TE group (p < 0.05). Also, the ankle was significantly more plantarflexed during swing at 2 and 8 weeks postoperative for the TE group (p < 0.05). In contrast, there were no significant differences in the SPM analysis among timepoints in the PET-SI group for the knee or ankle. Conclusions: Our findings suggest that the artificial tibialis cranialis tendon effectively replaced the biomechanical function of the native tendon. Future studies should investigate (1) effects of artificial tendons on other (e.g., neuromuscular) tissues and systems and (2) biomechanical outcomes when there is a delay between tendon injury and artificial tendon implantation. [ABSTRACT FROM AUTHOR]

Closed System Transfer Devices (CSTDs) are increasingly used in healthcare settings to facilitate compounding of hazardous drugs but increasingly also therapeutic proteins. However, their use may significantly impact the quality of the sterile product. For example, contamination of the product solution may occur by leaching of silicone or particulates from the CSTDs. It was therefore the aim of the present study to identify and quantify the types of silicone oil in a panel of typically used CSTDs. Particles found after simulated CSTD compounding processes were evaluated using Light Obscuration and Micro-Flow Imaging and were confirmed to be silicone oil particles. The number of particulates shed from CTSDs was in single cases exceeding pharmacopeial limits for a final parenteral product. Using X-ray microtomography, lubrication was shown to be primarily applied at connecting parts of the CSTD. Quantitative and qualitative analysis by Fourier transform infrared spectroscopy (FTIR) revealed a total released amount between 0.8 and 16 mg per CSTD of polydimethylsiloxane or polymethyltrifluoropropylsiloxane per CSTD. While pronounced differences in total silicone content between CSTDs were observed, it did not fully correlate with particle contamination in the test solutions, potentially due to variations in CSTD design. The impact of typical surfactants in biological formulations on silicone migration into product was additionally evaluated. We conclude that CSTDs may compromise final product quality, as (different types of) silicone oil may be released from these devices and contaminate the administered product. [ABSTRACT FROM AUTHOR]

Fabrication of waterproof decorative paintings has attracted a great deal of interest. In this work, in situ reaction using poly(glycidyl methacrylate) (PGMA) and polyhedral oligomeric silsesquioxane with amino group at end (amino-POSS) was utilized to fabricate coatings at surfaces of papery/cloth decorative paintings via spray, which endowed the decorative paintings with excellent hydrophobicity, transparency, and weather ability. Firstly, ring opening of epoxy groups in PGMA, cross-linking structure in coatings, and strong coating/painting interface adhesion were achieved. Then, surface morphology of coatings was observed, and high surface roughness was confirmed. Next, high transparency and thermal stability of coatings were confirmed. Finally, surface water-contact-angles (WCAs) of coatings with various substrates were tested as a function of POSS content. Weathering resistances of coating surface on cloth substrate were studied. Coatings exhibit excellent properties such as high light transmittance (over 80%), high glass-transition temperature (upper limit ~ 113 ℃), high hydrophobicity (maximum WCA ~ 149°), and strong weathering resistances (the aged WCAs over 140°). Work innovation lies in simultaneously gained high hydrophobicity, good transparency, and strong weather ability. This work might pave a road for fabricating excellent coatings for protecting decorative paintings. [ABSTRACT FROM AUTHOR]

Two families of room temperature vulcanized PDMS with different hardness were thermally aged. Mechanical properties were monitored by tensile tests, and macromolecular architecture was followed by differential scanning calorimetry (crystallization) and sol–gel analysis (swelling degree). Data showed that PDMS display a loss of plasticity due to a crosslinking process. The main novelty was to describe mechanical behaviour by a hyperelastic so-called Ogden's model whose coefficients were correlated with macromolecular properties and then ageing degree. The model coefficients were also used to derive an embrittlement criterion. [ABSTRACT FROM AUTHOR]

A versatile, robust, and stable tetrabutylammonium difluorotriphenylsilicate (TBAT) catalyst has been deployed for efficient depolymerization of silicones. This catalyst is soluble in a variety of organic solvents and is stable up to 170 °C, enabling a wide range of reaction conditions under which F−-catalysed siloxane bond cleavage can be initiated. This effort offers significant advancement overcoming the traditional limitations of silicone depolymerization, such as high catalyst loading, storage and handling, and few viable reaction media. [ABSTRACT FROM AUTHOR]

Field concentration is often regarded as a problematic issue in soft electronics applications, especially when using curved electrodes, and in particular, those with sharp edges. However, field concentration can be turned into an advantage with appropriate device design. Herein, the applications of field concentration in hydrogel‐elastomer devices are explored. Three different types of electroluminescent hydrogel‐elastomer devices are fabricated using different types of electrodes and different light patterns. In addition, the effect of the field concentration can be extended into the bulk of the elastomer by preparing porous silicone elastomers and filling them with silicone oil. These devices are shown to be flexible and possess both good luminance and a long lifetime. [ABSTRACT FROM AUTHOR]

The case report describes a case of a 78-year-old patient after microlaryngosurgery with intubation and with stenosis in the area of the posterior glottic commissure. The solution method is a new procedure using a silicone stent inserted and sewn into the tunnel in the area of the stenosis. The silicone stent was removed after 5 weeks, and the remaining part of the stenosis was interrupted. The surgical procedure in the patient led to decannulation, voice improvement and increased the quality of life. This treatment method appears to be a suitable way of solving some types of stenosis in the area of the posterior glottic commissure. [ABSTRACT FROM AUTHOR]

Polytitaniumorganosilsesquioxanes were synthesized by the hydrolysis of triethoxysilanes with octyl and vinyl groups followed by the reaction with tetrabutoxytitanium and studied. [ABSTRACT FROM AUTHOR]