A Preliminary Retrospective Study to Assess the Short-Term Safety of Traditional Smooth or Microtextured Silicone Gel-Filled Breast Implants in Korea

Background and objectives We conducted this preliminary retrospective study to assess the short-term safety of silicone gel-filled breast implants (SGBIs) that are commercially available in Korean women. Materials and methods The current retrospective, observational study was conducted in a total of 2612 patients (n =2612) who underwent augmentation mammaplasty using breast implants at our hospitals between 1 January, 2017 and 31 August 2021. Results Overall, there were a total of 248 cases (9.49%) of postoperative complications; these include 112 cases of early seroma, 52 cases of shape deformation, 32 cases of CC, 12 cases of early hematoma, 12 cases of rupture, 12 cases of infection, 12 cases of stretch deformities with skin excess and 4 cases of rippling. Overall complication-free survival of the breast implant was estimated at 1564.32 ± 75.52 days (95% CI 1416.39–1712.32). Then, the Motiva Ergonomix™SilkSurface showed the longest survival (1528.00 ± 157.92 days [95% CI 1218.48–1837.56]), followed by the BellaGelÒSmoothFine (1458.4 ± 65.76 days [95% CI 1329.56–1587.28]), the SebbinÒ Sublimity (1322.00 ± 51.20 days [95% CI 1221.64–1422.32]), the BellaGelÒ Smooth (1138.72 ± 161.28 days [95% CI 822.6–1454.84), the MentorÒ MemoryGel™ Xtra (698.4 ± 52.64 days [95% CI 595.28–801.52]) and the NatrelleÒ INSPIRA™ (380.00 ± 170.88 days [95% CI 45.04–714.96]) in the decreasing order. On subgroup analysis, both the Motiva ErgonomixTM and MentorÒ MemoryGel™ Xtra showed no postoperative complications. However, the BellaGelÒSmoothFine, SebbinÒ Sublimity and BellaGelÒ Smooth showed incidences of 8.87%, 4.84% and 1.61%, respectively. A subgroup analysis also showed differences in incidences of postoperative complications between microtextured and smooth breast implants (15.18% vs. 16.67%). Conclusions In conclusion, our results indicate that diverse types of an SGBI are commercially available and their safety profile varies according to the manufacturer. Plastic surgeons should consider the safety profile of each device in selecting the optimal types of the device for Korean women who are in need of an implant-based augmentation mammaplasty. However, this warrants a single-surgeon, single-center studywith long periods of follow-up.

Comparison of a Novel Silicone Gel Wound Dressing versus Bacitracin after Follicular Unit Extraction Hair Transplantation

Background Follicular unit extraction (FUE) hair transplantation subjects are excellent candidates to assess wound dressings. The wound surface area is large and adequately delineated to allow randomization, while in-patient split scalp designs allow patients to serve as their own controls. Objectives This randomized, single-blinded, split-scalp comparison trial compares a novel, film-forming silicone gel-- Stratamed (Stratpharma AG, Basel, Switzerland) -- to Bacitracin (McKesson Medical-Surgical Inc., Richmond, VA) in subjects undergoing FUE. Methods Twenty subjects were randomized to receive Stratamed and Bacitracin on alternating sides of the scalp. Primary outcome measures included blinded clinician assessments of edema, erythema, crusting, healing response and outcome preference. Secondary measures included subject-reported assessments of pain and pruritis as well as FaceQ scores taken at post-FUE days two through six. Results Twenty subjects were enrolled. Nineteen completed the trial. All subjects were non-smokers, and none had medical comorbidities expected to impact wound healing. An average of 1778 follicles per subject were harvested. No adverse events were reported, and all subjects healed by day 7. Healing response and outcome preference were significantly higher at day 1 in the Stratamed group and by day 7, both groups were similar. There were no significant differences between groups for edema, erythema, or crusting. There were no significant differences between groups for subject-reported outcomes of pain, pruritis, or FACE-Q scores. When asked which product they preferred using, 44% of subjects preferred using Stratamed versus 22% who preferred Bacitracin. Conclusions The Stratamed wound dressing was well-tolerated in patients undergoing FUE. Stratamed may speed the healing response in the early phase of wound healing.

Post-Buckling Spring Vibration Isolator Using Silicone Gel Column: A Theoretical and Experimental Study

Based on the design of a post-buckling silicone gel column (SGC), a novel type of low-frequency vibration isolator is presented, and the vibration isolation performance of this isolator is studied by combining theoretical analysis and experimental verification. The stiffness characteristics of the post-buckling SGC are derived, and its recovery force curves with different parameters are analyzed using two kinds of elliptic integral functions. Displacement transmissibility is formulated using harmonic balance method (HBM), and the influences of the excitation amplitude, damping ratio, SGC section diameter, and Young’s modulus are discussed in terms of the transmissibility. The performance of the SGC system is verified through a series of experimental studies based on the developed experimental prototype. The result shows that the proposed post-buckling spring vibration isolator has a good vibration isolation effect, especially in the low-frequency domain, which may provide a feasible novel design idea for a low-frequency vibration isolator.

Characteristics of the Polishing Effects for the Stainless Tubes in Magnetic Finishing with Gel Abrasive

Magnetic abrasive finishing (MAF) is a fast, high efficiency and high-precision polishing method on the surface machining of the metals. Furthermore, MAF also can be utilized to polish the stainless tubes in industrial applications; however, stainless tubes are often a non-magnetic material that makes it difficult for the magnetic field line to penetrate into the stainless tubes, thus reducing the magnetic forces in the inner tubes polishing. That is why stainless tubes are not easy to finish using traditional MAF. Therefore, magnetic finishing with gel abrasive (MFGA) applies gels mixed with steel grit and abrasives that were developed to improve the polishing efficiency and surface uniformity of the steel elements. In this study, a guar gum or silicone gel mixed with steel grit and silicon carbides are used as the magnetic abrasive gel to polish the stainless inner tubes. A DC motor was used to control the rotation speed of the chuck and an AC induction motor connected with an eccentric cam to produce the reciprocating motion of the workpiece were utilized to finish the inner surface of stainless tubes in the polishing process. The parameters of abrasive concentration, abrasive particle sizes, rotation speeds of motor and electric currents were used to investigate the surface roughness and the removal of materials from the stainless tubes. The experimental results showed that since guar gum had better fluidity than the silicone gel did, guar gum created excellent polishing efficiency in MFGA. Furthermore, the surface roughness of the stainless tube decreased from 0.646 μm Ra to below 0.056 μm Ra after processing for 30 min with the parameters of current 3A, gel abrasive with guar gum, rotational speed 1300 rpm and vibration frequency 4 Hz.

Assembly Reliability and Molding Material Comparison of Miniature Integrated High Power Module with Insulated Metal Substrate

Given the increasing demand for power density and lightweight specifications, the discrete transistor outline-type package is no longer sufficient for personal vehicle. The new generation of high-power drive needs excellent heat dissipation and miniaturized system simultaneously. However, a traditional architecture of power module, direct bonding copper substrate, has serious warpage deformation and limitation of the heat dissipation. Therefore, a power module with an insulated metal substrate (IMS) is proposed. The proposed power module has a smaller volume, better electrical and thermal performance, and high reliability to be utilized in personal vehicles. A fine-quality assembly process is also presented and verified. Furthermore, two different kinds of molding materials that are widely used in power modules, silicone gel and epoxy, are utilized. The IMS-type module with silicone gel molding fails the temperature cycling test (TCT) with the delamination of the solder layer. The module with epoxy successfully passes the automotive-grade reliability tests, including TCT, highly accelerated stress test, high-temperature reverse bias, and intermittent operational life test according to the standard of AEC-Q101. The finite element analysis for the IMS power module is presented and analyzed under the condition of TCT to estimate the mechanical behavior of the solder layer. The equivalent plastic strain of solder layer with silicone gel and epoxy are 0.76 and 0.08 after TCT, separately. The main reason can be attributed to the coefficient of thermal expansion between the IMS and molding material. According to the analyzed results, the effect of molding material should not be ignored in the power modulus.