Efficient mapping of the thalamocortical monosynaptic connectivity in vivo by tangential insertions of high-density electrodes in the cortex.

The thalamus provides the principal input to the cortex and therefore understanding the mechanisms underlying cortical integration of sensory inputs requires to characterize the thalamocortical connectivity in behaving animals. Here, we propose tangential insertions of high-density electrodes into mouse cortical layer 4 as a method to capture the activity of thalamocortical axons simultaneously with their synaptically connected cortical neurons. This technique can reliably monitor multiple parallel thalamic synaptic inputs to cortical neurons, providing an efficient approach to map thalamocortical connectivity in both awake and anesthetized mice.

Ultrafast universal fabrication of configurable porous silicone-based elastomers by Joule heating chemistry.

Silicone-based elastomers (SEs) have been extensively applied in numerous cutting-edge areas, including flexible electronics, biomedicine, 5G smart devices, mechanics, optics, soft robotics, etc. However, traditional strategies for the synthesis of polymer elastomers, such as bulk polymerization, suspension polymerization, solution polymerization, and emulsion polymerization, are inevitably restricted by long-time usage, organic solvent additives, high energy consumption, and environmental pollution. Here, we propose a Joule heating chemistry method for ultrafast universal fabrication of SEs with configurable porous structures and tunable components (e.g., graphene, Ag, graphene oxide, TiO2, ZnO, Fe3O4, V2O5, MoS2, BN, g-C3N4, BaCO3, CuI, BaTiO3, polyvinylidene fluoride, cellulose, styrene-butadiene rubber, montmorillonite, and EuDySrAlSiOx) within seconds by only employing H2O as the solvent. The intrinsic dynamics of the in situ polymerization and porosity creation of these SEs have been widely investigated. Notably, a flexible capacitive sensor made from as-fabricated silicone-based elastomers exhibits a wide pressure range, fast responses, long-term durability, extreme operating temperatures, and outstanding applicability in various media, and a wireless human-machine interaction system used for rescue activities in extreme conditions is established, which paves the way for more polymer-based material synthesis and wider applications.

Bioinspired Structures Made of Silicone Nanofilaments for Upcycling Waste Masks to Reusable N95 Respirators.

The increasing demand for personal protective equipment such as single-use masks has led to large amounts of nondegradable plastic waste, aggravating economic and environmental burdens. This study reports a simple and scalable approach for upcycling waste masks via a chemical vapor deposition technique, realizing a trichome-like biomimetic (TLB) N95 respirator with superhydrophobicity (water contact angle ≥150°), N95-level protection, and reusability. The TLB N95 respirator comprising templated silicone nanofilaments with an average diameter of ∼150 nm offers N95-level protection and breathability comparable to those of commercial N95 respirators. The TLB N95 respirator can still maintain its N95-level protection against particulate matter and viruses after 10 disinfection treatment cycles (i.e., ultraviolet irradiation, microwave irradiation, dry heating, and autoclaving), demonstrating durable reusability. The proposed strategy provides new insight into upcycle waste masks, breaking the existing design and preparation concept of reusable masks.

Highly Durable Silicone-Based Elastomers Achieved Through the Synergy of Bi-Incompatible Soft Segments and Multi-Scale Hydrogen Bonds.

Developing a silicone elastomer with high strength, exceptional toughness, good crack tolerance, healability, and recyclability, poses significant challenges due to the inherent trade-offs between these properties. Herein, the design of silicone-based elastomers with a nanoscopic microphase separation structure and comprehensive mechanical properties is achieved by combining bi-incompatible soft segments and multi-scale hydrogen bonds. The formation of multi-scale hydrogen bonds involving urethane, urea, and 2-ureido-4[1H]-pyrimidinone (UPy) facilitates efficient reversible crosslinking of the synthesized polymer containing thermodynamically incompatible poly(dimethylsiloxane) (PDMS) and poly(propylene glycol) (PPG). The dynamic dissociation and recombination of hydrogen bonds, coupled with the forced compatibility and spontaneous separation of bi-incompatible soft segments, can effectively dissipate energy, particularly in the crack region during the stretching process. The obtained silicone-based elastomer exhibits a high break strength of 8.0 MPa, good elongation at break of 1910%, ultrahigh toughness of 67.8 MJ m-3, and unprecedented fracture energy of 31.8 kJ m-2 while maintaining their thermal stability, hydrophobicity, healability, and recyclability. This resilient and long-lasting silicone-based elastomer exhibits significant potential for use in flexible electronic devices.

Improved Outcomes with Heavy Silicone Oil in Complex Primary Retinal Detachment: A Large Multicenter Matched Cohort Study.

PURPOSE: To establish whether Densiron 68, a heavier-than-water endotamponade agent, is an effective alternative to conventional light silicone oil in primary rhegmatogenous retinal detachment (RD) surgery for eyes with inferior breaks in the detached retina and severe proliferative vitreoretinopathy (PVR). DESIGN: Cohort study of routinely collected data from the European Society of Retina Specialists and British and Eire Association of Vitreoretinal Surgeons vitreoretinal database between 2015 and 2022. PARTICIPANTS: All consecutive eyes that underwent primary rhegmatogenous RD surgery using Densiron 68 or light silicone oil as an internal tamponade agent. METHODS: To minimize confounding bias, we undertook 2:1 nearest-neighbor matching on inferior breaks, large inferior rhegmatogenous RDs, PVR, and, for visual analyses, baseline visual acuity (VA) between treatment groups. We fit regression models including prognostically relevant covariates, treatment-covariate interactions, and matching weights. We used g-computation with cluster-robust methods to estimate marginal effects. For nonlinear models, we calculated confidence intervals (CIs) using bias-corrected cluster bootstrapping with 9999 replications. MAIN OUTCOME MEASURES: Presence of a fully attached retina and VA at least 2 months after oil removal. RESULTS: Of 1061 eyes enrolled, 426 and 239 were included in our matched samples for anatomic and visual outcome analyses, respectively. The primary success rate was higher in the Densiron 68 group (113 of 142; 80%) compared with the light silicone oil group (180 of 284; 63%), with an adjusted odds ratio of 1.90 (95% CI, 1.63-2.23, P < 0.001). We also observed a significant improvement favoring Densiron 68 of -0.26 logarithm of the minimum angle of resolution (logMAR) in postoperative VA between the 2 groups (95% CI, -0.43 to -0.10, P = 0.002). The anatomic benefit of using Densiron 68 in eyes with inferior retinal breaks and large detachments was more pronounced among eyes with PVR grade C. We found no evidence of visual effect moderation by anatomic outcome or foveal attachment. CONCLUSIONS: Densiron achieved higher anatomic success rates and improved visual outcomes compared with conventional light silicone oil in eyes with inferior retinal pathology and severe PVR. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Skin simulants for wound ballistic investigation - an experimental study.

Gunshot wound analysis is an important part of medicolegal practice, in both autopsies and examinations of living persons. Well-established and studied simulants exist that exhibit both physical and biomechanical properties of soft-tissues and bones. Current research literature on ballistic wounds focuses on the biomechanical properties of skin simulants. In our extensive experimental study, we tested numerous synthetic and natural materials, regarding their macromorphological bullet impact characteristics, and compared these data with those from real bullet injuries gathered from medicolegal practice. Over thirty varieties of potential skin simulants were shot perpendicularly, and at 45°, at a distance of 10 m and 0.3 m, using full metal jacket (FMJ) projectiles (9 × 19 mm Luger). Simulants included ballistic gelatine at various concentrations, dental silicones with several degrees of hardness, alginates, latex, chamois leather, suture trainers for medical training purposes and various material compound models. In addition to complying to the general requirements for a synthetic simulant, results obtained from dental silicones shore hardness 70 (backed with 20 % by mass gelatine), were especially highly comparable to gunshot entry wounds in skin from real cases. Based on these results, particularly focusing on the macroscopically detectable criteria, we can strongly recommend dental silicone shore hardness 70 as a skin simulant for wound ballistics examinations.

Ongoing Laboratory Performance Study on Chemical Analysis of Hydrophobic and Hydrophilic Compounds in Three Aquatic Passive Samplers.

The quality of chemical analysis is an important aspect of passive sampling-based environmental assessments. The present study reports on a proficiency testing program for the chemical analysis of hydrophobic organic compounds in silicone and low-density polyethylene (LDPE) passive samplers and hydrophilic compounds in polar organic chemical integrative samplers. The median between-laboratory coefficients of variation (CVs) of hydrophobic compound concentrations in the polymer phase were 33% (silicone) and 38% (LDPE), similar to the CVs obtained in four earlier rounds of this program. The median CV over all rounds was 32%. Much higher variabilities were observed for hydrophilic compound concentrations in the sorbent: 50% for the untransformed data and a factor of 1.6 after log transformation. Limiting the data to the best performing laboratories did not result in less variability. Data quality for hydrophilic compounds was only weakly related to the use of structurally identical internal standards and was unrelated to the choice of extraction solvent and extraction time. Standard deviations of the aqueous concentration estimates for hydrophobic compound sampling by the best performing laboratories were 0.21 log units for silicone and 0.27 log units for LDPE (factors of 1.6 to 1.9). The implications are that proficiency testing programs may give more realistic estimates of uncertainties in chemical analysis than within-laboratory quality control programs and that these high uncertainties should be taken into account in environmental assessments.

Flame Retardant Exposure in Vehicles Is Influenced by Use in Seat Foam and Temperature.

Flame retardants (FRs) are added to vehicles to meet flammability standards, such as US Federal Motor Vehicle Safety Standard FMVSS 302. However, an understanding of which FRs are being used, sources in the vehicle, and implications for human exposure is lacking. US participants (n = 101) owning a vehicle of model year 2015 or newer hung a silicone passive sampler on their rearview mirror for 7 days. Fifty-one of 101 participants collected a foam sample from a vehicle seat. Organophosphate esters (OPEs) were the most frequently detected FR class in the passive samplers. Among these, tris(1-chloro-isopropyl) phosphate (TCIPP) had a 99% detection frequency and was measured at levels ranging from 0.2 to 11,600 ng/g of sampler. TCIPP was also the dominant FR detected in the vehicle seat foam. Sampler FR concentrations were significantly correlated with average ambient temperature and were 2-5 times higher in the summer compared to winter. The presence of TCIPP in foam resulted in ∼4 times higher median air sampler concentrations in winter and ∼9 times higher in summer. These results suggest that FRs used in vehicle interiors, such as in seat foam, are a source of OPE exposure, which is increased in warmer temperatures.

Structural Optimization of PA12/MVQ@POE-g-MAH Ternary Composite for Superior Toughness and Low-Temperature Resistance.

To enhance the low-temperature toughness and resistance of the engineering plastic polyamide PA12, this study introduces novel PA12/MVQ@POE-g-MAH ternary composites using a two-step process and dynamic curing. Analytical results indicate that incorporating MVQ@POE-g-MAH into the PA12 matrix markedly enhances its toughness and heat resistance. As the MVQ@POE-g-MAH content increases, the elongation at break of PA12 composites significantly expands from 52.83% to 204.69%, and the notch impact strength escalates from 8.69 to 74.34 kJ m-2. In addition, the brittleness temperature of PA12 decreases from -59.5 to -67.0 °C. Experimental findings confirm that POE-g-MAH is dispersed at the interface between MVQ and PA12, creating an encapsulated structure of MVQ@POE-g-MAH. This enhancement significantly broadens the potential applications of PA12 by improving its toughness, and resistance to both low and high temperatures, as well as impact endurance.

High Hydrophilic and Antibacterial Efficient UV-Curable Silicone-Containing Choline Chloride Quaternary Ammonium Salts Functionalized Materials.

Antibacterial materials with high hydrophobicity have drawbacks such as protein adsorption, bacterial contamination, and biofilm formation, which are responsible for some serious adverse health events. Therefore, antibacterial materials with high hydrophilicity are highly desired. In this paper, UV-curable antibacterial materials are prepared from silicone-containing Choline chloride (ChCl) functionalized hyperbranched quaternary ammonium salts (QAS) and tri-hydroxylethyl acrylate phosphate (TAEP). The materials show high hydrophilic performance because their water contact angle is as low as 19.3°. The materials also exhibit quite high antibacterial efficiency against S. aureus over 95.6%, fairly high transmittance over 90%, and good mechanical performance with tensile strength as high as 6.5 MPa. It reveals that it is a feasible strategy to develop antibacterial materials with low hydrophobicity from silicone-modified ChCl-functionalized hyperbranched QAS.

Silicone wristbands reveal ubiquitous human exposure to ortho-phthalates and non-ortho-phthalate plasticizers in Southern California.

In the United States and abroad, ortho-phthalates and non-ortho-phthalate plasticizers continue to be used within a diverse array of consumer products. Prior California-specific biomonitoring programs for ortho-phthalates have focused on rural, agricultural communities and, to our knowledge, these programs have not measured the potential for exposure to non-ortho-phthalate plasticizers. Therefore, the potential for human exposure to ortho-phthalates and non-ortho-phthalate plasticizers have not been adequately addressed in regions of California that have higher population density. Since there are numerous sources of ortho-phthalates and non-ortho-phthalate plasticizers in population-dense, urban regions, the objective of this study was to leverage silicone wristbands to quantify aggregate ortho-phthalate and non-ortho-phthalate plasticizer exposure over a 5-day period across two different cohorts (2019 and 2020) of undergraduate students at the University of California, Riverside (UCR) that commute from all over Southern California. Based on 5 d of aggregate exposure across two different cohorts, total ortho-phthalate plus non-ortho-phthalate plasticizer concentrations ranged, on average, from ∼100,000-1,000,000 ng/g. Based on the distribution of individual ortho-phthalate and non-ortho-phthalate plasticizer concentrations, the concentrations of di-isononyl phthalate (DiNP, a high molecular weight ortho-phthalate), di (2-ethylhexyl) phthalate (DEHP, a high molecular weight ortho-phthalate), and di-2-ethylhexyl terephthalate (DEHT, a non-ortho-phthalate plasticizer) detected within wristbands were higher than the remaining seven ortho-phthalates and non-ortho-phthalate plasticizers measured, accounting for approximately 94-97% of the total mass depending on the cohort. Overall, our findings raise concerns about chronic DiNP, DEHP, and DEHT exposure in urban, population-dense regions throughout California.

Degradation of trichloroacetic acid by Fe/Ni bimetallic reactive PMS with hierarchical layered structure.

Overuse of chlorinated disinfectants leads to a significant accumulation of disinfection by-products. Trichloroacetic acid (TCA) is a typical carcinogenic disinfection by-product. The efficacy of the conventional degradation process is reduced by the complex nature of its structure, causing a yearly increase in its prevalence within the ecological environment and consequent infliction of significant harm. In this paper, TCA was chosen as the research subject, Fe/Ni bimetallic nanoparticles were employed as the reducing catalyst, ZIF-8@HMON as the catalytic carrier combined with Fe/Ni nanoparticles, and peroxymonosulfate (PMS) was introduced to construct the reducing-advanced oxidation synergistic system and investigated the effect of this system on the degradation performance and degradation pathway of TCA. Various characterization techniques, including TEM, SEM, XRD, FT-IR, XPS, BET, were employed to investigate the morphology, element composition and structure of composite materials analysis. Moreover, the conditions for TCA degradation can be optimized by changing the experimental environment. The results showed that 25 mg of composite catalyst (mole ratio Fe: Ni = 1:1) and 10 mg of PMS effectively degraded TCA within 20-80 mg/L range at pH = 3 and 55 °C, achieving maximum degradation within 20 min. Finally, the potential pathways of TCA degradation were analyzed using EPR and LC-MS, and the corresponding reaction mechanisms were proposed.

Vision loss associated with silicone oil endotamponade in vitreoretinal surgery - a review.

PURPOSE: To clarify the definition, prevalence and classification of different types of unexplained vision loss associated with silicone oil (SO) endotamponades (SO in situ (SOIS) or after removal of SO (ROSO)) in vitreoretinal surgery and identifying the most specific clinical findings and suggesting possible causes. METHODS: Review of the literature regarding randomized clinical trials (RCTs), retrospective case-control, cohort studies and case series evaluating the risk of using SO, published in English between 1994 and 2023, conducting a computer-based search of the following databases: PubMed, Web of Science, Scopus and Embase. The search was supplemented using the Medline option 'Related Articles' and consulting review articles on the topic. RESULTS: Findings from reported clinical examinations in SOIS and ROSO are analyzed and finally different theories regarding the underlying pathophysiology are described. From the clinical point of view, findings have been found in OCT, OCTA, microperimetry and electrophysiological studies. Other clearly identifiable causes of vision loss related to the use of SO are listed and commented as differential diagnosis. Finally, the different physiopathological theories of the two types of causes of unexplained vision have been analyzed. CONCLUSION: Unexpected vision loss under or after SO tamponade (SOIS and ROSO) is a significant concern which is probably underestimated because it is not a clearly defined and known entity. The most frequently described changes were in the ganglion cell complex but this unexpected vision loss remains a serious and unexplained concern for vitreoretinal surgeons and should be identified by clinicians, addressed by manufacturers and reported to Health Authorities as a serious incident according to the new regulation.

A minimum specification dataset for liquid ocular endotamponades: recommendations by a European expert panel.

PURPOSE: To propose a minimum specification dataset to characterize liquid ocular endotamponades (OEs), namely silicone oil (SO), heavy SO (HSO), perfluorodecalin (PFD), and perfluoro-octane (PFO), in terms of physicochemical properties, purity and available evidence of safety, in line with ISO16672:2020. METHODS: An evidence-based consensus using the expert panel technique was conducted. Two facilitators led a committee of 11 European experts. Facilitators prepared a dataset for each compound including the list of specifications relevant for the safety, identified by the group members on the basis of expertise and a comprehensive literature review. Each item was ranked by each member using a 9-point scale from 1 "absolutely to not include" to 9 "absolutely to include" in two rounds followed by discussion. Only items reaching consensus (score ≥ 7 from ≥ 75% of members) were included in the final datasets. RESULTS: For all OEs, consensus was reached to include manufacturer, density, refractive index, chemical composition, dynamic viscosity, interfacial and surface tension, endotoxins, in vitro cytotoxicity assessment, and any evidence from ex vivo and/or in vivo tests for safety assessment. Additional specifications were added for SO (molecular weight distribution, content of oligosiloxanes with MW ≤ 1000 g/mol, spectral transmittance) and PFD/PFO (% of pure PFD/PFO in the final product, vapor pressure, chemical analyses performed for safety assessment). CONCLUSION: The proposed evidence-based minimum specification datasets for SO, HSO, PFD, and PFO have the potential to provide surgeons and health service purchasers with an easily available overview of the most relevant information for the safety assessment of OEs.

Posterior capsular radial sign: a novel method to confirm anterior vitreous cortex resection in phacovitrectomy.

BACKGROUND: The main purpose of this paper is to introduce a method that can accurately locate the posterior capsule of the lens to facilitate a relatively complete resection of the anterior vitreous body. METHODS: A total of 51 patients in the experimental group and control group were enrolled in this study. Phacoemulsification combined with vitrectomy was performed in all cases. After the cataract procedure was completed in the control group, the surgeon performed a conventional anterior vitrectomy with the operative eye. In the experimental group, anterior vitrectomy was performed according to the threadiness corrugation of the posterior capsule of the lens. During the operation, with the help of triamcinolone, two surgeons confirmed the resection of the anterior vitreous cortex; the best corrected visual acuity and intraocular pressure of all patients were recorded at 1 week, 1 month and 3 months after surgery. RESULTS: Fifty patients underwent phacoemulsification combined with vitrectomy, except one patient in the experimental group who was lost to follow-up. After surgery, no significant complications were observed in all patients except two patients in the control group with temporary increases in intraocular pressure. There was no significant difference in preoperative visual acuity between the two groups (t = 0.83, P = 0.25). Both groups had varying degrees of improvement in best corrected visual acuity at 1 week, 1 month and 3 months after surgery. Moreover, there was no significant difference in BCVA between the two groups at the three follow-up time points (t=-1.15, -1.65, -1.09, P = 0.53, 0.21, 0.23). After surgery, no significant complications were observed in all patients except two patients in the control group with temporary increases in intraocular pressure. Incomplete resection of the anterior vitreous cortex was observed in 2 patients in each group, but there was no significant difference (χ2 = 7.81, P > 0.05). CONCLUSION: In the process of cataract surgery combined with vitrectomy, thready corrugation appears in the posterior capsule of the lens and is an important sign of its localization. Anterior vitrectomy can be accomplished safely and effectively with the help of thread-like corrugation, and the surgical effect is almost the same as that of traditional surgery. Especially suitable for beginners in vitreous surgery.

The effect of cumulative energy in repeated subliminal transscleral cyclophotocoagulation: a retrospective study.

BACKGROUND: The long-term safety and efficacy of repeated applications of subliminal transscleral cyclophotocoagulation (SL-TSCPC) with a focus on cumulative energy was evaluated in glaucoma patients. METHODS: In this retrospective, multicentric study the data of a total of 82 eyes with various causes of glaucoma that were treated with a single or multiple applications of SL-TSCPC were collected. Treatments were performed under general or local anesthesia with an 810 nm diode laser. Power was 2000 mW; duty cycle, 31.3%; total treatment duration, 80-320 s; equaling a total energy of 50-200 J per treatment session. Fifty-five eyes (55 patients) presented for all follow-ups, and these eyes were selected for further statistical analysis. The mean age was 60.0 ± 17.1 years, and 22 (40%) of the patients were female. Intraocular pressure (IOP) and dependence on further glaucoma medication were evaluated at 12 months following the initial treatment. RESULTS: Eyes underwent 1 or 2 consecutive SL-TSCPC treatments. Median (min-max) baseline IOP of 34 (13-69) decreased to 21.5 (7-61), 22 (8-68), 20 (9-68), and 19.5 (3-60) mmHg at the 1, 3, 6, and 12-month postoperative timepoints respectively. The mean (± SD) IOP decrease at 12 months was 26 ± 27%, 39 ± 32%, and 49 ± 33% in the low (below 120 J, n = 18), medium (120-200 J, n = 24), and high (above 200 J, n = 13) cumulative energy groups respectively. At the 12-month timepoint, oral carbonic anhydrase use was discontinued in ¾ of the cases. CONCLUSIONS: It was found that the repeated application of SL-TSCPC safely and efficiently decreases IOP in a Caucasian population with heterogenous causes of glaucoma, eyes with silicone oil responded to a greater extent. Inclusion of cumulative energy scales may contribute to better addressing repeated procedures in a standardized fashion.

Effect of silicone oil versus gas tamponade on macular layer microstructure after pars plana vitrectomy for macula on rhegmatogenous retinal detachment.

PURPOSE: To analyze structural changes in the macular retinal layers and sub-foveal choroidal thickness (SFCT) in eyes after macula-on rhegmatogenous retinal detachment (RRD) repair by pars plana vitrectomy with either silicone oil (SO) or gas tamponade, and the effect of these changes on visual acuity. PATIENTS AND METHODS: Retrospective study which included 26 eyes in the SO Group and 32 in the Gas Group. Optical coherence tomography (OCT) scans of the affected eyes were obtained before surgery, and 3 months after PPV in the Gas Group, and during silicone oil in situ and 3 months after SO removal, in the SO Group. Qualitative assessment of photoreceptor layer and foveal contour, along with quantitative assessment of macular retinal thickness and SFCT was performed. Postoperative OCT macular microstructural changes were recorded and correlated to corrected distance visual acuity (CDVA). Intraocular pressure (IOP) was measured preoperative and at 3 months post operative. RESULTS: There was a 2-line loss (from 20/28 preoperatively to 20/40 at final follow-up) of CDVA in the SO Group (p=0.051), while there was no statistically significant change in CDVA in the Gas Group (p=0.786). There was no significant correlation between CDVA loss and duration of silicon tamponade (r=-0.031, p=0.893). There was a statistically significant increase in IOP from its baseline to final follow-up of 0.7 mmHg in the SO Group (p=0.023) while there was no statistically significant change in IOP in the Gas Group. During silicone oil tamponade, there was approximately 11% and 5% of retinal and sub-foveal choroidal thinning respectively, which was moderately resolved following silicone oil removal. 20% (5/24) of eyes in the SO Group had qualitative flattening of foveal contour during SO tamponade that resolved after SO removal. CONCLUSION: Thinning of the macula was noticed after macula-on RRD repair with SO tamponade. Such thinning was only partially reversible after the removal of SO.

Tracheobronchial stents: an expanding prospect.

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.

Management of macula-on giant retinal tear detachments- outcome of pars-plana-vitrectomy with silicone oil versus gas tamponade.

BACKGROUND: To compare the outcome of eyes with a macula-on giant retinal tear (GRT) detachment treated with pars-plana-vitrectomy (PPV) depending on the used endotamponade. METHODS: All consecutive cases with a macula-on GRT-associated rhegmatogenous retinal detachment (RRD) managed with PPV between 2007 and 2022 were retrospectively assessed depending on the selected endotamponade. By reviewing medical charts and surgical protocols the pre- and intraoperative parameters were analysed in detail. The number of vitreoretinal (VR) procedures needed for reattachment, the redetachment rate and the functional outcome were evaluated. Eyes treated with primary silicone oil (SO) tamponade were compared to eyes with primary gas tamponade. Cases with pre-existing conditions affecting outcome e.g. macula-off situation, history of trauma, status after complicated cataract surgery, former VR surgery or proliferative vitreoretinopathy grade C or higher were excluded. RESULTS: Overall, 51 eyes of 45 patients with a macula-on GRT detachment were treated with PPV and SO (n = 32; 63%) or gas (n = 19; 37%) endotamponade in the observed period. Eyes with primary SO tamponade underwent on average 2.3 (SD 0.8) VR procedures and had a redetachment rate of 13% (n = 4). Eyes with gas tamponade showed a higher redetachment rate of 32% (n = 6) with a mean number of 1.6 (SD 1.0) PPV procedures. Postoperative best-corrected visual acuity (BCVA) was significantly better in eyes with primary gas tamponade (mean logMAR BCVA 0.32; SD 0.30) compared to eyes with SO (mean logMAR BCVA 0.60; SD 0.42; p = 0.008). CONCLUSIONS: Surgical management of GRT-associated RRDs is complex. In clinical routine often SO is used as endotamponade. Because of known disadvantages (second procedure necessary for SO removal, unexplained SO-related visual loss, secondary glaucoma, SO emulsification) some VR surgeons prefer a gas tamponade. In our cohort, eyes with a gas compared to SO tamponade showed higher redetachment rates. However, the final postoperative BCVA was significantly better in eyes with gas compared to SO tamponade. TRIAL REGISTRATION: The trial protocol was approved by the local ethics committee on 25th of November 2022 (Ethikkommission der Universität Regensburg, Votum 22-3166-104).

Large skin defect in Type V aplasia cutis congenita treated with conservative treatment: a case report.

Aplasia cutis congenita (ACC) is a congenital disorder that can be classified into nine types, with Type I ACC being the most common. Type V ACC associated with fetus papyraceus is a rare subtype of ACC. We report the case of a Type V ACC in a male newborn with extensive abdominal skin defects. The patient received conservative treatment using hydrogel foam and silicone foam dressings. Approximately five weeks later, the patient was discharged when more than 60% of the skin had completed epithelialization. After discharge from West China Second University Hospital, Chengdu , the patient continued to be followed up regularly at the Burns and Plastic Surgery Clinic at local hospital in Gansu. We followed up the child by telephone. After 4 months of follow-up, scar tissue formation was observed in the trunk area. The infant is 2 years and 5 months old now, physical examination did not reveal any organ problems.