Autonomous Triboelectric Smart Textile Sensor for Vital Sign Monitoring.

Wearable smart textile sensors for monitoring vital signs are fast, noninvasive, and highly desirable for personalized health management to diagnose health anomalies such as cardiovascular diseases and respiratory dysfunction. Traditional biosignal sensors, with power consumption issues, constrain the use of wearable medical devices. This study introduces an autonomous triboelectric smart textile sensor (AUTS) made of reduced graphene oxide/manganese dioxide/polydimethylsiloxane (RGO-M-PDMS) and polytetrafluoroethylene (TEFLON)-knitted silver electrode, offering promise for vital sign monitoring with self-powering, flexibility, and wearability. The sensor exhibits impressive output performance, with a sensitivity of 7.8 nA/kPa, response time of ≈40 ms, good stability of >15,000 cycles, stretchability of up to 40%, and machine washability of >20 washes. The AUTS has been integrated to the TriBreath respiratory belt for monitoring respiratory signals and pulse strap for pulse signals concurrently at different body pulse points. These sensors wirelessly transmitted the acquired biosignals to a smartphone, demonstrating the potential of a self-powered and real-time vital sign monitoring system.

Ridge Preservation Combined With Open Barrier Membrane Technique in Case of Postextractive Oroantral Communication: A Case Series Retrospective Study.

After dental extraction, a physiological phenomenon of reabsorption of the dentoalveolar process is triggered, especially if periradicular lesions are present, which can sometimes be associated with oroantral communication in the upper posterior maxilla. To investigate a minimally invasive approach, 19 patients undergoing tooth extraction in the posterosuperior maxilla were recruited. All cases presented an oroantral communication with a diameter of 2-5 mm after tooth extraction and the alveolar process and, in some cases, with a partial defect of 1 or more bony walls. In these cases, a single surgical procedure was used to preserve the alveolar ridge using an open barrier technique with an exposed dense polytetrafluoroethylene membrane. The bottom of the extraction socket was filled with a collagen fleece. The residual bone process was reconstructed using a biomaterial based on carbonate-apatite derived from porcine cancellous bone. After 6 months, all patients were recalled and subjected to radiographic control associated with an implant-prosthetic rehabilitation plan. Data relating to the sinus health status and the average height and thickness of the regenerated bone were collected. Radiographic evaluation verified the integrity of the maxillary sinus floor with new bone formation, detecting a vertical bone dimension between 3.1 mm and 7.4 mm (average 5.13 ± 1.15 mm) and a horizontal thickness between 4.2 mm and 9.6 mm (average 6.86 ± 1.55 mm). The goal of this study was to highlight the advantage of managing an oroantral communication and, simultaneously, obtain the preservation and regeneration of the alveolar bone crest. The open barrier technique appears to be effective for the minimally invasive management of oroantral communication up to 5 mm in diameter in postextraction sites, with a good regeneration of hard and soft tissue.

Development of an efficient, effective, and economical technology for proteome analysis.

We present an efficient, effective, and economical approach, named E3technology, for proteomics sample preparation. By immobilizing silica microparticles into the polytetrafluoroethylene matrix, we develop a robust membrane medium, which could serve as a reliable platform to generate proteomics-friendly samples in a rapid and low-cost fashion. We benchmark its performance using different formats and demonstrate them with a variety of sample types of varied complexity, quantity, and volume. Our data suggest that E3technology provides proteome-wide identification and quantitation performance equivalent or superior to many existing methods. We further propose an enhanced single-vessel approach, named E4technology, which performs on-filter in-cell digestion with minimal sample loss and high sensitivity, enabling low-input and low-cell proteomics. Lastly, we utilized the above technologies to investigate RNA-binding proteins and profile the intact bacterial cell proteome.

Performances of PTFE and PVDF membranes in achieving the discharge limit of mixed anodic oxidation coating wastewaters treated by membrane distillation.

The mixed wastewater generated by anodic oxidation coating facilities contains high levels of various contaminants, including iron, aluminum, conductivity, chemical oxygen demand (COD), and sulfate. In this study, the effectiveness of the membrane distillation (MD) process using polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) membranes was investigated to treat mixed wastewater from an anodized coating factory. The results indicate that both hydrophobic membranes effectively removed targeted contaminants. However, the PTFE membrane achieved higher removal efficiencies, with over 99% removal of sulfate, conductivity, iron, and aluminum, 85.7% of COD, and 86% of total organic carbon (TOC). In contrast, the PVDF membrane exhibited a significant decline in removal efficiency as the temperature increased and performed well only at lower feed temperatures. The PTFE membranes outperformed the PVDF membranes in treating chemically intensive anodic oxidation wastewaters. This superiority can be attributed to the PTFE membrane's morphology and structure, which are less influenced by feed water temperature and chemicals. Additionally, its slippery surface imparts anti-adhesion properties, effectively preventing membrane fouling, and maintaining the treated water quality and flux for longer operation time.

Microbial colonization in the partially exposed nonabsorbable membrane during alveolar ridge preservation.

AIM: This study evaluated the impact of the partial exposition of the nonabsorbable membrane (dPTFE) on microbial colonization during bone healing. MATERIALS AND METHODS: Patients indicated for tooth extraction were randomized to dPTFE group (n = 22) - tooth extraction and alveolar ridge preservation (ARP) using an intentionally exposed dPTFE membrane and USH group (n = 22) - tooth extraction and unassisted socket healing. Biofilm samples were collected at the barrier in the dPTFE and on the natural healing site in the USH after 3 and 28 days. Samples from the inner surface of the dPTFE barrier were also collected (n = 13). The microbiome was evaluated using the Illumina MiSeq system. RESULTS: Beta diversity was different from 3 to 28 days in both groups, and at 28 days, different microbial communities were identified between therapies. The dPTFE was characterized by a higher prevalence and abundance of gram-negative and anaerobic species than USH. Furthermore, the inner surface of the dPTFE membrane was colonized by a different community than the one observed on the outer surface. CONCLUSION: Intentionally exposed dPTFE membrane modulates microbial colonization in the ARP site, creating a more homogeneous and anaerobic community on the inner and outer surfaces of the membrane. CLINICAL RELEVANCE: DPTFE promoted faster biofilm colonization and enrichment of gram-negative and anaerobes close to the regenerated site in the membrane's inner and outer surfaces. dPTFE membrane can be used exposed to the oral site, but approaches for biofilm control should still be considered. The study was retrospectively registered at Clinicaltrials.gov (NCT04329351).

Effect of ultraviolet aged polytetrafluoroethylene microplastics on copper bioavailability and Microcystis aeruginosa growth.

Microplastics (MPs) are ubiquitous in aquatic environments, which can act as carriers to affect the bioavailability of heavy metals. The aging process in the environment changes the physicochemical properties of MPs, thereby affecting their environmental behavior and co-toxicity with other pollutants. However, relevant research is limited. In this study, we compared the properties and Cu2+ adsorption capacity of pristine and aged polytetrafluoroethylene (PTFE) MPs and further explored the influence on copper bioavailability and bio-effects on Microcystis aeruginosa. Aging process induced surface oxidation and cracks of PTFE MPs, and decreased the stability of MPs in water by increasing zeta potential. PTFE MPs had a strong adsorption capacity for Cu2+ and increased the bioavailability of copper to microalgae, which was not affected by the aging process. Pristine and aged PTFE MPs adhered to cyanobacterium surfaces and caused shrinkage and deformation of cells. Inhibition of cyanobacterium growth, photosynthesis and reduction of total antioxidant capacity were observed in the treatment of PTFE MPs. Combined exposure of pristine MPs and Cu2+ had stronger toxic effects to cyanobacterium, and increased Microcystin-LR release, which could cause harm to aquatic environment. Aging reduced the toxic effects of PTFE MPs on microalgae. Furthermore, soluble exopolysaccharide (EPS) content was significantly higher in co-exposure of aged MPs and Cu2+, which could reduce the toxicity to cyanobacterium cells. These results indicate that aging process alleviates the toxicity to microalgae and environmental risks caused by PTFE MPs. This study improves understanding of the combined toxicity of aged MPs and metals in freshwater ecosystems.

Rising Perfluorocyclobutane (PFC-318, c-C4F8) Emissions in China from 2011 to 2020 Inferred from Atmospheric Observations.

Global atmospheric emissions of perfluorocyclobutane (c-C4F8, PFC-318), a potent greenhouse gas, have increased rapidly in recent years. Combining atmospheric observations made at nine Chinese sites with a Lagrangian dispersion model-based Bayesian inversion technique, we show that PFC-318 emissions in China grew by approximately 70% from 2011 to 2020, rising from 0.65 (0.54-0.72) Gg year-1 in 2011 to 1.12 (1.05-1.19) Gg year-1 in 2020. The PFC-318 emission increase from China played a substantial role in the overall increase in global emissions during the study period, contributing 58% to the global total emission increase. This growth predominantly originated in eastern China. The regions with high emissions of PFC-318 in China overlap with areas densely populated with polytetrafluoroethylene (PTFE) factories, implying that fluoropolymer factories are important sources of PFC-318 emissions in China. Our investigation reveals an emission factor of approximately 3.02 g of byproduct PFC-318 emissions per kg of hydrochlorofluorocarbon-22 (HCFC-22) feedstock use in the production of tetrafluoroethylene (TFE) (for PTFE production) and hexafluoropropylene (HFP) if we assume all HCFC-22 produced for feedstock uses in China are pyrolyzed to produce PTFE and HFP. Further facility-level sampling and analysis are needed for a more precise evaluation of emissions from these factories.

Endoscope-assisted microvascular decompression in hemifacial spasm with a teflon bridge.

BACKGROUND: Microvascular conflicts in hemifacial spasm typically occur at the facial nerve's root exit zone. While a pure microsurgical approach offers only limited orientation, added endoscopy enhances visibility of the relevant structures without the necessity of cerebellar retraction. METHODS: After a retrosigmoid craniotomy, a microsurgical decompression of the facial nerve is performed with a Teflon bridge. Endoscopic inspection prior and after decompression facilitates optimal Teflon bridge positioning. CONCLUSIONS: Endoscope-assisted microsurgery allows a clear visualization and safe manipulation on the facial nerve at its root exit zone.

Enhancing polytetrafluoroethylene (PTFE) coated film for food processing: Unveiling surface transformations through oxygenated plasma treatment and parameter optimization using response surface methodology.

Spray drying fruit juice powders poses challenges because sugars and organic acids with low molecular weight and a low glass transition temperature inherently cause stickiness. This study employed a hydrophobic polytetrafluoroethylene (PTFE) film to mimic the surface of the drying chamber wall. The Central Composite Design (CCD) using response surface methodology investigated the impact of power (X1, Watt) and the duration of oxygenated plasma treatment (X2, minutes) on substrate contact angle (°), reflecting surface hydrophobicity. To validate the approach, Morinda citrofolia (MC) juice, augmented with maltodextrins as drying agents, underwent spray drying on the improved PTFE-coated surface. The spray drying process for MC juice was performed at inlet air temperatures of 120, 140, and 160°C, along with Noni juice-to-maltodextrin solids ratios of 4.00, 1.00, and 0.25. The PTFE-coated borosilicate substrate, prepared at a radio frequency (RF) power of 90W for 15 minutes of treatment time, exhibited a porous and spongy microstructure, correlating with superior contact angle performance (171°) compared to untreated borosilicate glass. Optimization data indicated that the PTFE film attained an optimum contact angle of 146.0° with a specific combination of plasma RF operating power (X1 = 74 W) and treatment duration (X2 = 10.0 minutes). RAMAN spectroscopy indicated a structural analysis with an ID/IG ratio of 0.2, while Brunauer-Emmett-Teller (BET) surface area analysis suggested an average particle size of less than 100 nm for all coated films. The process significantly improved the powder's hygroscopicity, resistance to caking, and moisture content of maltodextrin-MC juice. Therefore, the discovery of this modification, which applies oxygen plasma treatment to PTFE-coated substrates, effectively enhances surface hydrophobicity, contact angle, porosity, roughness, and ultimately improves the efficacy and recovery of the spray drying process.

Robotic Renal Vein Bypass: A Novel Technique for Treating a Challenging Case of Nutcracker Syndrome.

This case report highlights the successful application of a robotic-assisted surgical approach in managing Nutcracker syndrome. The patient, a 36-year-old female presented with severe symptoms and underwent robotic left renal vein transposition after failing conservative management. The procedure was performed through a minimally invasive approach utilizing the Da Vinci robotic system™ which offers enhanced visualization and precision. However, challenges arose during the renal vein anastomosis due to tension and poor flow through the transposition, requiring two revisions with a bovine pericardial patch. Ultimately, an 8 mm ringed PTFE bypass was anastomosed from the distal left renal vein to the Inferior Vena Cava. Despite these challenges, the patient experienced a successful outcome with complete symptom resolution of this complicated pathology.

Histological Evaluation of Alveolar Ridge Preservation Using Different Bone Grafts: Clinical Study Analysis Part II.

To compare histologically the percentage of bone formation 12-20 weeks after ridge augmentation using 2 different techniques. Tooth loss is associated with 3-dimensional bone remodeling and ridge atrophy. Ridge preservation procedures can prevent alveolar bone volume loss. Different techniques and materials are used to preserve the alveolar ridge. Computer-generated randomization software was used to assign 2 ridge preservation techniques for 11 extraction sites. In group I, type I bovine Achilles tendon collagen plugs with bioactive resorbable calcium apatite crystals (CPCAC) were placed, and in group II, cortico-cancellous bone chips (CCBC) mix and an expanded polytetrafluoroethylene (ePTFE) barrier membrane were placed. The histomorphometric studies were performed using a computer-based image analysis system (ImageJ 1.4, National Institute of Health, Bethesda, Md) to calculate the pixel area of bone tissue and the remaining bone graft material. The histomorphometric data were analyzed using a Student t test to compare the measurements between the 2 experimental groups. This parametric statistical test was employed to determine if there were any statistically significant differences in the quantitative histological parameters between the groups. The sockets that received CPCAC showed a lower (31.89%) percentage of native bone surface area compared with the CCBC group (43.87%). However, the difference was not statistically significant (P < .05). In addition, the CPCAC group showed evidence of foreign-body reaction. The CCBC graft covered with an ePTFE barrier may induce more bone formation with minimal inflammation in an extraction socket compared with a collagen plug with calcium apatite crystals. In addition, histological analysis of the CPCAC graft showed evidence of foreign-body reaction, which indicates a negative clinical impact.

Snake-shaped ePTFE nasal tip graft combined with conchal cartilage in Asian rhinoplasty: a retrospective cohort study.

BACKGROUND: Lacking a nasal tip projection is a common deformity of Asian nasals. Various commonly used nasal tip grafts require dissecting septal perichondrium, most of them are autologous cartilage with a nonintegrated design. A snake-shaped expanded polytetrafluoroethylene (ePTFE) nasal tip graft is an integrated, stable tip graft without any additional assembly and splicing, conforming to the nasal anatomy characteristics of Asians. METHOD: A retrospective study was performed on Asian patients who underwent rhinoplasty in the nasal tip at Peking University Third Hospital from 2015 to 2022. Nasal tip grafts were categorized into three groups: snake-shaped ePTFE combined with conchal cartilage (n = 15), only costal cartilage (n = 25), and only conchal cartilage (n = 17). Patients were excluded if their rhinoplasty did not involve any of the grafts above. Visual Analogue Scale, FACE-Q Nose, FACE-Q Nostril, Nasal Obstruction Symptom Evaluation scale, and Rhinoplasty Outcome Evaluation scale were used to evaluate the preoperative and postoperative results. RESULTS: Fifty-three (93.0%) cases had low nasal dorsum and 46 (80.7%) cases had short nose. There was no significant difference in complication rates among the three groups. The difference between preoperative and postoperative scale scores was statistically significant among the three groups (p < 0.05). Score improvements, including all scales, were the highest in the costal cartilage group and lowest in the conchal cartilage group. CONCLUSIONS: Snake-shaped ePTFE nasal tip grafts can be an effective integrated alternative that provides long-term safety and efficacy compared with traditional autogenous implants (conchal and costal cartilages).

Half- and full-grafting alveolar ridge preservation with different sealing materials: A three-arm randomized clinical trial.

OBJECTIVE: The objective of this study is to investigate the effect of different alveolar ridge preservation (ARP) approaches on bone resorption and their potential for facilitating implant placement. MATERIALS AND METHODS: Patients who underwent one or two tooth extractions with a desire for restoration were included in the study. The participants were randomly assigned to one of three groups for ARP. The groups were as follows: (1) Half grafting of bovine bone mineral (DBBM-C) covered with non-resorbable dense polytetrafluoroethylene (dPTFE) membrane (Test 1 group); (2) Half grafting of bovine bone mineral (DBBM-C) covered with collagen membrane (Test 2 group); and (3) Full grafting with collagen membrane (DBBM-C + Collagen membrane) as the Control group. After 6-month healing period, the evaluation encompassed clinical, radiographic, implant-related outcomes, and the factors contributing to hard and soft tissue alterations. RESULTS: Enrollment in this study comprised 56 patients. At the 6-month follow-up, radiographic analysis in computed beam computed tomography images was conducted for 18, 19, and 19 patients with 18, 20, and 20 tooth sites in Test 1, Test 2, and Control groups, respectively. Additionally, a total of 15, 17, and 17 patients with 15, 18, and 17 implants were evaluated. Based on radiographic analysis, all groups showed limited ridge resorption at 1 mm from crest horizontally (Test 1: 1.29 ± 1.37; Test 2: 1.07 ± 1.07; Control: 1.54 ± 1.33 mm, p = 0.328), while the Control group showed greater radiographic bone height gain in mid-crestal part vertically (Test 1: 0.11 ± 1.02; Test 2: 0.29 ± 0.83; Control: -0.46 ± 0.95 mm, p = 0.032). There were no significant intergroup differences in terms of keratinized mucosal width, bone density, insertion torque, and the need of additional bone graft. However, the use of a dPTFE membrane resulted in a significantly higher vertical mucosal thickness (Test 1: 2.67 ± 0.90; Test 2: 3.89 ± 1.08; Control: 2.41 ± 0.51 mm, p < 0.001). CONCLUSIONS: The study showed comparable dimensional preservation with limited vertical shrinkage, while thin buccal bone plate, non-molar sites, and large discrepancy between buccal and palatal/lingual height may contribute to greater shrinkage. Thicker mucosa with dPTFE membrane required further investigation for interpretation. CLINICAL TRIAL REGISTRATION NUMBER: NCT06049823. This clinical trial was not registered prior to participant recruitment and randomization.

UV-C side-emitting optical fiber-based disinfection: a promising approach for infection control in tight channels.

The growth of pathogenic bacteria in moist and wet surfaces and tubing of medically relevant devices results in serious infections in immunocompromised patients. In this study, we investigated and demonstrated the successful implementation of a UV-C side-emitting optical fiber in disinfecting medically relevant pathogenic bacteria (Pseudomonas aeruginosa and Methicillin-resistant Staphylococcus aureus [MRSA]) within tight channels of polytetrafluoroethylene (PTFE). PTFE is a commonly used material both in point-of-use (POU) water treatment technologies and medical devices (dental unit water line [DUWL], endoscope). For a 1-m-long PTFE channel, up to ≥6 log inactivation was achieved using a 1-m-long UV side-emitting optical fiber (SEOF) with continuous 16-h exposure of low UV-C radiation ranging from ~0.23 to ~29.30 µW/cm2. Furthermore, a linear model was used to calculate the inhibition zone constant (k`), which enables us to establish a correlation between UV dosage and the extent of inactivated surface area (cm2) for surface-bound Escherichia coli on a nutrient-rich medium. The k` value for an irradiance ranging from ~150 to ~271.50 µW/cm2 was calculated to be 0.564 ± 0.6 cm·cm2/mJ. This study demonstrated the efficacy of SEOFs for disinfection of medically relevant microorganisms present in medically and domestically relevant tight channels. The impact of the results in this study extends to the optimization of operational efficiency in pre-existing UV surface disinfection setups that currently operate at UV dosages exceeding the optimal levels.IMPORTANCEGermicidal UV radiation has gained global recognition for its effectiveness in water and surface disinfection. Recently, various works have illustrated the benefit of using UV-C side-emitting optical fibers (SEOFs) for the disinfection of tight polytetrafluoroethylene (PTFE) channels. This study now demonstrates its impact for disinfection of medically relevant organisms and introduces critical design calculations needed for its implementation. The flexible geometry and controlled emission of light in these UV-SEOFs make them ideal for light distribution in tight channels. Moreover, the results presented in this manuscript provide a novel framework that can be employed in various applications, addressing microbial contamination and the disinfection of tight channels.

Crosslinking and fluorination reinforced PTFE nanofibrous membrane with excellent amphiphobic performance for low-scaling membrane distillations.

Membrane distillation (MD) has emerged as a promising technology for desalination and concentration of hypersaline brine. However, the efficient preparation of a structurally stable and salinity-resistant membrane remains a significant challenge. In this study, an amphiphobic polytetrafluoroethylene nanofibrous membrane (PTFE NFM) with exceptional resistance to scaling has been developed, using an energy-efficient method. This innovative approach avoids the high-temperature sintering treatment, only involving electrospinning with PTFE/PVA emulsion and subsequent low-temperature crosslinking and fluorination. The impact of the PVA and PTFE contents, as well as the crosslinking and subsequent fluorination on the morphology and MD performance of the NFM, were systematically investigated. The optimized PTFE NFM displayed robust amphiphobicity, boasting a water contact angle of 155.2º and an oil contact angle of 132.7º. Moreover, the PTFE NFM exhibited stable steam flux of 52.1 L·m-2·h-1 and 26.7 L·m-2·h-1 when fed with 3.5 wt % and 25.0 wt % NaCl solutions, respectively, and an excellent salt rejection performance (99.99 %, ΔT = 60 °C) in a continuous operation for 24 h, showing exceptional anti-scaling performance. It also exhibited stable anti-wetting and anti-fouling properties against surfactants (sodium dodecyl sulfate) and hydrophobic contaminants (diesel oil). These results underscore the significant potential of the PTFE nanofibrous membrane for practical applications in desalination, especially in hypersaline or polluted aqueous environments.

Microplastic and PTFE contamination of food from cookware.

Microplastics are a prolific environmental contaminant that have been evidenced in human tissues. Human uptake of microplastic occurs via inhalation of airborne fibres and ingestion of microplastic-contaminated foods and beverages. Plastic and PTFE-coated cookware and food contact materials may release micro- and nanoplastics into food during food preparation. In this study, the extent to which non-plastic, new plastic and old plastic cookware releases microplastics into prepared food is investigated. Jelly is used as a food simulant, undergoing a series of processing steps including heating, cooling, mixing, slicing and storage to replicate food preparation steps undertaken in home kitchens. Using non-plastic cookware did not introduce microplastics to the food simulant. Conversely, using new and old plastic cookware resulted in significant increases in microplastic contamination. Microplastics comprised PTFE, polyethylene and polypropylene particulates and fibrous particles, ranging 13-318 µm. Assuming a meal was prepared daily per the prescribed methodology, new and old plastic cookware may be contributing 2409-4964 microplastics per annum into homecooked food. The health implications of ingesting microplastics remains unclear.

A self-assembly and cellular migration based fabrication of high-density 3D tubular constructs of barrier forming membranes.

Three-dimensional (3D) in vitro models, superior in simulating physiological conditions compared to 2D models, offer intricate cell-cell and cell-ECM interactions with diverse signaling cues like fluid shear stress and growth factor gradients. Yet, developing 3D tissue barrier models, specifically perfusable luminal structures with dense, multicellular constructs maintained for extended durations with oxygen and nutrients, remains a technical challenge. Here, we describe a molding-based approach for the fabrication of free-standing, perfusable, high cellular density tissue constructs using a self-assembly and migration process to form functional barriers. This technique utilizes a polytetrafluoroethylene (PTFE)-coated stainless-steel wire, held by stainless steel needles, as a template for a perfusable channel within an elongated PDMS well. Upon adding a bio-ink mix of cells and collagen, it self-assembles into a high cell density layer conformally around the wire. Removing the wire reveals a hollow construct, connectable to an inlet and outlet for perfusion. This scalable method allows creating varied dimensions and multicellular configurations. Notably, post-assembly, cells such as human umbilical vein endothelial cells (HUVECs) migrate to the surface and form functional barriers with adherens junctions. Permeability tests and fluorescence imaging confirm that these constructs closely mimic in vivo endothelial barrier permeability, exhibiting the lowest permeability among all in vitro models in the literature. Unlike traditional methods involving uneven post-seeding of endothelial cells leading to subpar barriers, our approach is a straightforward alternative for fabricating complex perfusable 3D tissue constructs and effective tissue barriers for use in various applications, including tissue engineering, drug screening, and disease modeling.

A Systematic Review and Meta-Analysis of Heparin-Bonded Expanded Polytetrafluoroethylene Grafts for Below-The-Knee Femoral Bypass Surgery.

BACKGROUND: Heparin-bonded expanded polytetrafluoroethylene (hb-ePTFE) synthetic grafts are an alternative to autologous vein grafts (AVG) for surgical bypass interventions in lower limb peripheral arterial disease (LLPAD). However, the clinical benefits of hb-ePTFE grafts have not been reviewed systematically for patients undergoing below-the-knee (BK) surgical bypass. This study aimed to meta-analyze available data on the utility of hb-ePTFE in patients undergoing BK surgical bypass. METHODS: Medline, Embase, and Cochrane databases were searched, restricted to material in English with no date restriction. In addition, proceedings from relevant congresses were screened going back 2 years. The search was performed in December 2021. Eligible studies included prospective or retrospective comparative studies or prospective single-arm cohorts with an hb-ePTFE arm. Methodological quality was assessed with the ROBINS-I criteria. Outcomes included primary patency, amputation/limb salvage, and overall survival. Clinical outcomes were expressed as event rates. Studies were compared using meta-analysis to generate a standardized mean event rate for each outcome, with its 95% confidence interval (95% CI), using a random-effects model. RESULTS: Following deduplication, 10,263 records were identified and 261 were assessed as full texts. No prospective comparative studies were identified. The level of evidence was uniformly low. Seventeen publications describing data from 9 individual patient cohorts met the inclusion criteria. These cohorts included a total of 1,452 patients undergoing BK surgical bypass with hb-ePTFE. The primary patency rate was 78.9% [95% CI: 72.2-85.7%] at 1 year, 68.2% [95% CI: 62.8-73.6%] at 2 years, decreasing to 48.0% [95% CI: 27.3-68.7%] at 5 years. The secondary patency rate was 84.8% [95% CI: 77.0-92.5%] at 1 year and 68.9% [95% CI: 43.0-94.9%] at 3 years; the 1-year limb salvage rate was 88.3% [95% CI: 79.6-97.1%] at 1 year and 79.0% [95% CI: 56.7-100%] at 3 years. CONCLUSIONS: In patients undergoing BK bypass surgery, hb-ePTFE synthetic grafts, compared to uncoated grafts, perform well for patency and limb salvage. However, the quality of the evidence is low, and well-performed randomized clinical trials are needed to inform clinical decision-making on the choice of synthetic graft.

High-Density Polyethylene Custom Focusing Lenses for High-Resolution Transient Terahertz Biomedical Imaging Sensors.

Transient terahertz time-domain spectroscopy (THz-TDS) imaging has emerged as a novel non-ionizing and noninvasive biomedical imaging modality, designed for the detection and characterization of a variety of tissue malignancies due to their high signal-to-noise ratio and submillimeter resolution. We report our design of a pair of aspheric focusing lenses using a commercially available lens-design software that resulted in about 200 × 200-µm2 focal spot size corresponding to the 1-THz frequency. The lenses are made of high-density polyethylene (HDPE) obtained using a lathe fabrication and are integrated into a THz-TDS system that includes low-temperature GaAs photoconductive antennae as both a THz emitter and detector. The system is used to generate high-resolution, two-dimensional (2D) images of formalin-fixed, paraffin-embedded murine pancreas tissue blocks. The performance of these focusing lenses is compared to the older system based on a pair of short-focal-length, hemispherical polytetrafluoroethylene (TeflonTM) lenses and is characterized using THz-domain measurements, resulting in 2D maps of the tissue refractive index and absorption coefficient as imaging markers. For a quantitative evaluation of the lens effect on the image resolution, we formulated a lateral resolution parameter, R2080, defined as the distance required for a 20-80% transition of the imaging marker from the bare paraffin region to the tissue region in the same image frame. The R2080 parameter clearly demonstrates the advantage of the HDPE lenses over TeflonTM lenses. The lens-design approach presented here can be successfully implemented in other THz-TDS setups with known THz emitter and detector specifications.

Reconstruction method for massive lateral chest wall sarcoma using titanium plates and mesh: a case report.

BACKGROUND: Very large chest wall resections can lead to acute thoracic insufficiency syndrome due to the interdependence of lung expansion and thoracic volume. Chest wall tumor surgeries often encounter complications, with the size of the chest wall defect being a significant predictor. Several methods for large chest wall reconstruction have been described, aiming to provide stability, prevent flail chest, and ensure airtight closure. However, no single method fulfills all requirements. Composite chest wall reconstruction using titanium plates and Gore-Tex patches has shown the potential to minimize physiologic abnormalities caused by extensive defects. CASE PRESENTATION: A 42-year-old man with myxofibrosarcoma underwent multiple surgeries, chemotherapies, and radiation therapies due to repeated local recurrences. After right arm amputation and resection of the right third to fifth ribs, a local recurrence was detected. A 30 × 40 cm chest wall defect was resected en bloc, and a titanium plate was used for three-dimensional formability, preventing flail chest and volume loss. The Gore-Tex patch was then reconstructed into an arch shape, allowing lateral thoracic mobility. The patient recovered well and did not experience respiratory dysfunction or local recurrence but later succumbed to distant metastasis. CONCLUSIONS: In this case, the combination of a titanium plate and a Gore-Tex patch proved effective for reconstructing massive lateral chest wall defects. The approach provided stability, preserved thoracic volume, and allowed for lateral mobility. While the patient achieved a successful outcome in terms of local recurrence and respiratory function, distant metastasis remained a challenge for myxofibrosarcoma patients, and its impact on long-term prognosis requires further investigation. Nevertheless, the described procedure offers promise for managing extensive chest wall defects.