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1.
Sensors (Basel) ; 24(7)2024 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-38610278

RESUMO

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.


Assuntos
Lentes , Imagem Terahertz , Animais , Camundongos , Polietileno , Politetrafluoretileno , Temperatura Baixa
2.
Lab Chip ; 24(9): 2468-2484, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38563430

RESUMO

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.


Assuntos
Movimento Celular , Humanos , Movimento Celular/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana , Politetrafluoretileno/química , Membranas Artificiais , Dimetilpolisiloxanos/química , Desenho de Equipamento
3.
J Cardiothorac Surg ; 19(1): 245, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38632587

RESUMO

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.


Assuntos
Tórax Fundido , Sarcoma , Neoplasias Torácicas , Parede Torácica , Masculino , Humanos , Adulto , Parede Torácica/cirurgia , Titânio , Telas Cirúrgicas , Neoplasias Torácicas/cirurgia , Sarcoma/patologia , Politetrafluoretileno
4.
Water Res ; 256: 121594, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38615603

RESUMO

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.


Assuntos
Destilação , Membranas Artificiais , Nanofibras , Politetrafluoretileno , Politetrafluoretileno/química , Nanofibras/química , Destilação/métodos , Halogenação , Purificação da Água/métodos
5.
Sci Total Environ ; 929: 172577, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38641111

RESUMO

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.


Assuntos
Contaminação de Alimentos , Microplásticos , Microplásticos/análise , Contaminação de Alimentos/análise , Politetrafluoretileno , Utensílios de Alimentação e Culinária , Monitoramento Ambiental , Plásticos/análise , Culinária
6.
Nat Commun ; 15(1): 2187, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38467617

RESUMO

Advancements in congenital heart surgery have heightened the importance of durable biomaterials for adult survivors. Dystrophic calcification poses a significant risk to the long-term viability of prosthetic biomaterials in these procedures. Herein, we describe the natural history of calcification in the most frequently used vascular conduits, expanded polytetrafluoroethylene grafts. Through a retrospective clinical study and an ovine model, we compare the degree of calcification between tissue-engineered vascular grafts and polytetrafluoroethylene grafts. Results indicate superior durability in tissue-engineered vascular grafts, displaying reduced late-term calcification in both clinical studies (p < 0.001) and animal models (p < 0.0001). Further assessments of graft compliance reveal that tissue-engineered vascular grafts maintain greater compliance (p < 0.0001) and distensibility (p < 0.001) than polytetrafluoroethylene grafts. These properties improve graft hemodynamic performance, as validated through computational fluid dynamics simulations. We demonstrate the promise of tissue engineered vascular grafts, remaining compliant and distensible while resisting long-term calcification, to enhance the long-term success of congenital heart surgeries.


Assuntos
Prótese Vascular , Calcinose , Ovinos , Animais , Estudos Retrospectivos , Calcinose/cirurgia , Materiais Biocompatíveis , Politetrafluoretileno
7.
Eur J Cardiothorac Surg ; 65(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38479833

RESUMO

OBJECTIVES: The Ross procedure represents an excellent treatment option in younger patients with aortic stenosis but is limited by poor availability of homografts. In this study, we investigated the hydrodynamic performance of 3 different types of right ventricular outflow tract replacement with pericardium or synthetic material. METHODS: Three different types of valved conduits were constructed using pericardium and/or synthetic material (Group PEPE: pericardial cusps and pericardial conduit, Group PEPR: pericardial cusps and Dacron conduit, Group PRPR: expanded polytetrafluoroethylene cusps and Dacron conduit). The conduits were designed according to the Ozaki method. Their hydrodynamic performance (effective orifice area, mean pressure gradient and leakage volume) were evaluated in a mock circulation loop at different hydrodynamic conditions. RESULTS: Hydrodynamic assessment showed significantly larger effective orifice area of PEPE and PEPR compared to PRPR under all conditions and there were no significant differences between PEPE and PEPR [for condition 2: PEPE 2.43 (2.35-2.54) cm2, PEPR: 2.42 (2.4-2.5) cm2, PRPR: 2.08 (1.97-2.21) cm2, adjusted pairwise comparisons: PEPE versus PEPR: P = 0.80, PEPE versus PRPR: P < 0.001, PEPR versus PRPR: P < 0.001]. Mean pressure gradient was significantly lower for PEPE and PEPR compared with PRPR, whereas no significant differences were seen between PEPE and PEPR. Leakage volume was significantly lower for PEPE and PEPR compared with PRPR under all conditions while leakage was similar between PEPE and PEPR. CONCLUSIONS: Pulmonary graft reconstruction with pericardium cusps showed superior hydrodynamic performance compared with polytetrafluoroethylene cusps. Our results suggest that it could be considered as an alternative substitute for right ventricular outflow tract replacement during the Ross procedure.


Assuntos
Próteses Valvulares Cardíacas , Obstrução do Fluxo Ventricular Externo , Humanos , Polietilenotereftalatos , Prótese Vascular , Desenho de Prótese , Obstrução do Fluxo Ventricular Externo/cirurgia , Politetrafluoretileno , Resultado do Tratamento , Estudos Retrospectivos
8.
Sci Rep ; 14(1): 4803, 2024 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-38413764

RESUMO

To investigate the endothelialization of covered and bare stents deployed in the canine carotid arteries and subclavian arteries for treating experimental aneurysms and arteriovenous fistulas, twenty aneurysms were created in 10 dogs, and 20 fistulas in another 10 dogs. The Willis balloon-expandable covered stent and a self-expandable covered stent were used to treat these lesions, and a self-expandable bare stent was deployed in the subclavian artery for comparison. Followed up for up to 12 months, the gross observation, pathological staining, and scanning electronic microscopic data were analyzed. Two weeks after creation of animal model, thirty self-expandable covered stents and ten balloon-expandable covered stents were deployed. Fifteen bare stents were deployed within the left subclavian arteries. Twenty days after stenting, the aneurysm significantly shrank. At 6 months, the thrombi within the aneurysm cavity were organized. Three to 12 months later, most covered and bare stents were covered by a thin transparent or white layer of endothelial intima. Layers of intima or pseudomembrane were formed on the stent 20-40 days after stent deployment. Over three months, the pseudomembrane became organized, thinner, and merged into the vascular wall. Under scanning electronic microscopy, the surface of covered and bare stents had only deposition of collagen fibers and rare endothelial cells 20-40 days after stenting. From three to ten months, the endothelial cells on the internal surface of stent became mature, with spindle, stripe-like or quasi round morphology along the blood flow direction. Over time, the endothelial cells became mature. In conclusion, three months after deployment in canines' arteries, the self-expandable bare and covered stents have mostly been covered by endothelial cells which become maturer over time, whereas the balloon-expandable covered stents do not have complete coverage of endothelial cells at three months, especially for protruding stent struts and areas. Over time, the endothelialization will become mature.


Assuntos
Aneurisma , Fístula Arteriovenosa , Cães , Animais , Células Endoteliais , Aneurisma/cirurgia , Aneurisma/patologia , Stents/efeitos adversos , Artérias Carótidas/cirurgia , Artérias Carótidas/patologia , Fístula Arteriovenosa/patologia , Politetrafluoretileno
9.
Biosensors (Basel) ; 14(2)2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38392007

RESUMO

We report a three-dimensional (3D) SERS substrate consisting of a silver nanoparticle (AgNP) coating on the skeleton-fiber surfaces of a polytetrafluoroethylene (PTFE) membrane. Simple thermal evaporation was employed to deposit Ag onto the PTFE membrane to produce grape-shaped AgNPs. The 3D-distributed AgNPs exhibit not only strong localized surface plasmon resonance (LSPR) but also strong hydrophobic performance. High-density hotspots via silver nano-grape structures and nanogaps, the large 3D interaction volume, and the large total surface area, in combination with the hydrophobic enrichment of the specimen, facilitate high-sensitivity sensing performance of such a SERS substrate for the direct detection of low-concentration molecules in water. An enhancement factor of up to 1.97 × 1010 was achieved in the direct detection of R6G molecules in water with a concentration of 10-13 mol/L. The lowest detection limit of 100 ppt was reached in the detection of melamine in water. Such a SERS sensor may have potential applications in food-safety control, environmental water pollution monitoring, and biomedical analysis.


Assuntos
Nanopartículas Metálicas , Análise Espectral Raman , Análise Espectral Raman/métodos , Prata/química , Nanopartículas Metálicas/química , Água , Politetrafluoretileno
10.
Environ Pollut ; 346: 123543, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38367691

RESUMO

The study focused on detecting and characterizing microplastics in outdoor and indoor air in Ranchi, Jharkhand, India during post-monsoon (2022) and winter (2023). Stereo microscopic analysis showed that plastic fibres had a dominant presence, fragments were less abundant, whereas fewer films could be detected in indoor and outdoor air. The atmospheric deposition of microplastics outdoors observed 465 ± 27 particles/m2/day in PM10 and 12104 ± 665 and 13833 ± 1152 particles/m2/day in PM2.5 in quartz and PTFE, respectively during the post-monsoon months. During winter, microplastic deposition rates in PM10 samples were found to be 689 ± 52 particles/m2/day and 19789 ± 2957 and 30087 ± 13402 in quartz and PTFE particles/m2/day respectively in PM2.5. The mean deposition rate in indoor environment during post-monsoon was 8.3 × 104 and 1.03 × 105 particles/m2/day in winter. During the post-monsoon period in PM10, there were fibres from 7.7 to 40 µm and fragments from 2.3 µm to 8.6 µm. Indoor atmospheric microplastics, fibres ranged from 1.2 to 47 µm and fragments from 0.9 to 16 µm present respectively during the post-monsoon season. Fibres and fragment sizes witnessed during winter were 3.6-6.9 µm and 2.3-34 µm, respectively. Indoor air films measured in the range of 4.1-9.6 µm. Fourier transform infrared analysis showed that outdoor air contained polyethylene, polypropylene, Polystyrene, whereas indoor air had polyvinyl chloride. Polyethylene mainly was present in outdoor air, with lesser polypropylene and polystyrene than indoors, where polyvinyl chloride and polyethylene were in dominant proportions. Elemental mapping of outdoor and indoor air samples showed the presence of elements on the microplastics. The HYSPLIT models suggest that the particles predominantly were coming from North-West during the post-monsoon season. Principal component analysis indicated wind speed and direction influencing the abundance of microplastics. Microplastics concentration showed strong seasonal influence and potential to act as reservoir of contaminants.


Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Poluição do Ar em Ambientes Fechados/análise , Poluentes Atmosféricos/análise , Microplásticos/análise , Plásticos/análise , Monitoramento Ambiental , Polipropilenos/análise , Poliestirenos/análise , Cloreto de Polivinila/análise , Quartzo , Índia , Polietileno/análise , Material Particulado/análise , Politetrafluoretileno
11.
Water Res ; 253: 121329, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38387269

RESUMO

Membrane fouling induced by oily substances significantly constrains membrane distillation performance in treating hypersaline oily wastewater. Overcoming this challenge necessitates a heightened fundamental understanding of the oil fouling phenomenon. Herein, the adsorption and penetration mechanism of oil droplets on hydrophobic membranes in membrane distillation process was investigated at the molecular level. Our results demonstrated that the adsorption and penetration of oil droplets were divided into four stages, including the free stage, contact stage, spreading stage, and equilibrium stage. Due to the extensive non-polar surface distribution of the polytetrafluoroethylene (PTFE) membrane (comprising 95.41 %), the interaction between oil molecules and PTFE was primarily governed by van der Waals interaction. Continuous oil droplet membrane fouling model revealed that the new oil droplet molecules preferred to penetrate into membrane pores where oil droplets already existed. The penetration of resin (a component of medium-quality oil droplets) onto PTFE membrane pores required the "pre-paving" of light crude oil. Finally, the ΔE quantitative structure-activity relationships (QSAR) models were developed to evaluate the penetration mechanism of pollutant molecules on the PTFE membrane. This research provides new insights for improving sustainable membrane distillation technologies in treating saline oily wastewater.


Assuntos
Águas Residuárias , Purificação da Água , Adsorção , Destilação , Membranas Artificiais , Purificação da Água/métodos , Politetrafluoretileno
12.
Urology ; 186: 131-138, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38367711

RESUMO

OBJECTIVE: To evaluate the efficacy and safety of the polytetrafluoroethylene (PTFE) mesh by comparing conventionally used polypropylene (PP) mesh in tension-free vaginal mesh (TVM) surgery for pelvic organ prolapse (POP). METHODS: We conducted an observational cohort study of patients who underwent TVM using a PTFE or PP mesh. PTFE was used from June 2019 to May 2021, and PP mesh from January 2018 to May 2019. Outcomes included POP recurrence, perioperative complications, and patient satisfaction. Restricted mean survival time was used to analyze POP recurrence, comparing the time to recurrence between the two groups at 1year after TVM. RESULTS: Of 171 patients, 104 underwent PP mesh placement (PP group) and 67 underwent PTFE mesh placement (PTFE group). POP recurrence was observed in 10 and nine patients in the PP and PTFE groups, respectively. The mean time until the recurrence in the PTFE group was significantly shorter than that in the PP group (restricted mean survival time difference: -20.3days; 95% CI, -40.1 to -0.5; P = .044). Subgroup analysis revealed the meantime until recurrence was significantly shorter in the PTFE group for postoperative periods 3months or less, ages >70years, and POP stage ≥3. There were no intervention cases in either group and no significant differences in the perioperative complications. Patient satisfaction was greater in the PTFE group after 3months postoperatively. CONCLUSION: TVM surgery with a PTFE mesh is more prone to recurrence than that with a PP mesh, but with higher patient satisfaction. Within 3months of surgery, elderly patients and those with advanced-stage POP require care to prevent recurrence.


Assuntos
Prolapso de Órgão Pélvico , Slings Suburetrais , Feminino , Humanos , Idoso , Estudos de Coortes , Telas Cirúrgicas , Prolapso de Órgão Pélvico/cirurgia , Prolapso de Órgão Pélvico/complicações , Polipropilenos , Politetrafluoretileno , Resultado do Tratamento
13.
Molecules ; 29(3)2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38338429

RESUMO

Photodynamic inactivation (PDI) is a highly effective treatment that can eliminate harmful microorganisms in a variety of settings. This study explored the efficacy of a curcumin-rich extract, Curcuma L., (Cur)- and essential oil component, trans-cinnamaldehyde, (Ca)-mediated PDI against Listeria monocytogenes ATCC 15313 (Lm) including planktonic cells and established biofilms on silicone rubber (Si), polytetrafluoroethylene (PTFE), stainless steel 316 (SS), and polyethylene terephthalate (PET). Applying Ca- and Cur-mediated PDI resulted in planktonic cell reductions of 2.7 and 6.4 log CFU/cm2, respectively. Flow cytometric measurements (FCMs) coupled with CFDA/PI and TOTO®-1 staining evidenced that Ca- doubled and Cur-mediated PDI quadrupled the cell damage. Moreover, the enzymatic activity of Lm cells was considerably reduced by Cur-mediated PDI, indicating its superior efficacy. Photosensitization also affected Lm biofilms, but their reduction did not exceed 3.7 log CFU/cm2. Cur-mediated PDI effectively impaired cells on PET and PTFE, while Ca-mediated PDI caused no (TOTO®-1) or only slight (PI) cell damage, sparing the activity of cells. In turn, applying Ca-mediate PDI to Si largely diminished the enzymatic activity in Lm. SS contained 20% dead cells, suggesting that SS itself impacts Lm viability. In addition, the efficacy of Ca-mediated PDI was enhanced on the SS, leading to increased damage to the cells. The weakened viability of Lm on Si and SS could be linked to unfavorable interactions with the surfaces, resulting in a better effect of Ca against Lm. In conclusion, Cur demonstrated excellent photosensitizing properties against Lm in both planktonic and biofilm states. The efficacy of Ca was lower than that of Cur. However, Ca bears potent antibiofilm effects, which vary depending on the surface on which Lm resides. Therefore, this study may help identify more effective plant-based compounds to combat L. monocytogenes in an environmentally sustainable manner.


Assuntos
Acroleína/análogos & derivados , Listeria monocytogenes , Compostos de Quinolínio , Tiazóis , Curcuma , Antibacterianos/farmacologia , Biofilmes , Politetrafluoretileno
14.
Port J Card Thorac Vasc Surg ; 30(4): 75-79, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38345877

RESUMO

INTRODUCTION: Popliteal artery aneurysms (PAA) can be very challenging, especially in cases of very large PAAs, with a minimal number of case reports published in the literature. METHODS: This is a case report of a 68-year-old male patient with hypertension, hyperlipidemia, diabetes, and schizophrenia who was found to have a giant (10x8x6cm) partially thrombosed PAA, treated with interposition polytetrafluoroethylene (PTFE) graft via a posterior approach. RESULTS: Under general anesthesia, the patient was placed in a prone position, and an extended lazy "S" incision was made on the popliteal fossa. After obtaining proximal and distal exposure, the aneurysm sac was skeletonized, preserving the popliteal vein and the tibial nerve. After proximal and distal control was obtained, the patient was systemically heparinized, and the aneurysm sac was opened. Some genicular branches were ligated inside the aneurysm, and part of the aneurysm sac was excised. A 7 mm PTFE graft was used for reconstruction in an end-to-end fashion. Suction drains were placed in the popliteal space, and the fascia and skin were approximated. The patient was discharged home on the 2nd postoperative day on aspirin and statin with ultrasound surveillance. The patient has remained asymptomatic during follow-up with a patent graft. CONCLUSIONS: Open surgical repair constitutes the gold standard of care for huge PAAs to prevent distal thromboembolic events and mass pressure effects from the aneurysm. Documentation of additional experience with open repair of huge PAAs would be beneficial and could help clinical decision-making.


Assuntos
Aneurisma , Aneurisma da Artéria Poplítea , Masculino , Humanos , Idoso , Aneurisma/diagnóstico , Joelho , Extremidade Inferior , Politetrafluoretileno , Artéria Poplítea/diagnóstico por imagem
15.
Biomech Model Mechanobiol ; 23(3): 845-860, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38361084

RESUMO

In complex cardiovascular surgical reconstructions, conduit materials that avoid possible large-scale structural deformations should be considered. A fundamental mode of mechanical complication is torsional buckling which occurs at the anastomosis site due to the mechanical instability, leading surgical conduit/patch surface deformation. The objective of this study is to investigate the torsional buckling behavior of commonly used materials and to develop a practical method for estimating the critical buckling rotation angle under physiological intramural vessel pressures. For this task, mechanical tests of four clinically approved materials, expanded polytetrafluoroethylene (ePTFE), Dacron, porcine and bovine pericardia, commonly used in pediatric cardiovascular surgeries, are conducted (n = 6). Torsional buckling initiation tests with n = 4 for the baseline case (L = 7.5 cm) and n = 3 for the validation of ePTFE (L = 15 cm) and Dacron (L = 15 cm and L = 25 cm) for each are also conducted at low venous pressures. A practical predictive formulation for the buckling potential is proposed using experimental observations and available theory. The relationship between the critical buckling rotation angle and the lumen pressure is determined by balancing the circumferential component of the compressive principal stress with the shear stress generated by the modified critical buckling torque, where the modified critical buckling torque depends linearly on the lumen pressure. While the proposed technique successfully predicted the critical rotation angle values lying within two standard deviations of the mean in the baseline case for all four materials at all lumen pressures, it could reliably predict the critical buckling rotation angles for ePTFE and Dacron samples of length 15 cm with maximum relative errors of 31% and 38%, respectively, in the validation phase. However, the validation of the performance of the technique demonstrated lower accuracy for Dacron samples of length 25 cm at higher pressure levels of 12 mmHg and 15 mmHg. Applicable to all surgical materials, this formulation enables surgeons to assess the torsional buckling potential of vascular conduits noninvasively. Bovine pericardium has been found to exhibit the highest stability, while Dacron (the lowest) and porcine pericardium have been identified as the least stable with the (unitless) torsional buckling resistance constants, 43,800, 12,300 and 14,000, respectively. There was no significant difference between ePTFE and Dacron, and between porcine and bovine pericardia. However, both porcine and bovine pericardia were found to be statistically different from ePTFE and Dacron individually (p < 0.0001). ePTFE exhibited highly nonlinear behavior across the entire strain range [0, 0.1] (or 10% elongation). The significant differences among the surgical materials reported here require special care in conduit construction and anastomosis design.


Assuntos
Teste de Materiais , Animais , Bovinos , Estresse Mecânico , Politetrafluoretileno/química , Suínos , Pressão , Criança , Humanos , Fenômenos Biomecânicos , Prótese Vascular , Torque , Pericárdio/fisiologia
17.
J Econ Entomol ; 117(2): 516-523, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38280183

RESUMO

Microplastics (MPs) have become a prominent environmental concern due to their ubiquity in various ecosystems and widespread distribution through multiple channels. In this study, the oral effects of 2,000 mesh polytetrafluoroethylene (PTFE) microplastics were tested against Drosophila melanogaster (Meigen), at concentrations of 0, 0.1, 1, 10, and 20. After exposure to a microplastic-containing medium for 20 days, energy metabolism, fecundity, spontaneous movement, and sleeping time were measured. The study results showed that glucose levels in male flies were significantly reduced after exposure to PTFE-MPs. Measurement of lipid and protein levels indicated an increase in males but decrease in females, whereas these changes were not statistically significant. Reduction in sleep time was also observed, especially in males at the concentration of 20 g/l. Our study indicates that chronic exposure of PTFE-MPs can change energy metabolism and the amount of sleep on D. melanogaster in a sex dependent and dose dependent way. The results of our study are hoped to contribute to a better understanding of the effects of microplastics as new pollutants on insects.


Assuntos
Drosophila melanogaster , Drosophilidae , Feminino , Masculino , Animais , Microplásticos/farmacologia , Plásticos/farmacologia , Politetrafluoretileno/farmacologia , Ecossistema
18.
Adv Mater ; 36(15): e2310216, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38237136

RESUMO

The sprayable hydrogel coatings that can establish robust adhesion onto diverse materials and devices hold enormous potential; however, a significant challenge persists due to monomer hydration, which impedes even coverage during spraying and induces inadequate adhesion post-gelation. Herein, a polycation-reinforced (PCR) surface bridging strategy is presented to achieve tough and sprayable hydrogel coatings onto diverse materials. The polycations offer superior wettability and instant electrostatic interactions with plasma-treated substrates, facilitating an effective spraying application. This PCR-based hydrogel coatings demonstrate tough adhesion performance to inert PTFE and silicone, including remarkable shear strength (161 ± 49 kPa for PTFE), interfacial toughness (198 ± 27 J m-2 for PTFE), and notable tolerance to cyclic tension (10 000 cycles, 200% strain, silicone). Meanwhile, this method can be applied to various hydrogel formulations, offering diverse functionalities, including underwater adhesion, lubrication, and drug delivery. Furthermore, the PCR concept enables the conformal construction of durable hydrogel coatings onto sophisticated medical devices like cardiovascular stents. Given its simplicity and adaptability, this approach paves an avenue for incorporating hydrogels onto solid surfaces and potentially promotes untapped applications.


Assuntos
Hidrogéis , Polieletrólitos , Silicones , Politetrafluoretileno , Reação em Cadeia da Polimerase
19.
Tex Heart Inst J ; 51(1)2024 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-38291908

RESUMO

BACKGROUND: Left ventricular free wall rupture (LVFWR) is a rare and fatal complication after acute myocardial infarction. Early recognition and aggressive treatment are recommended. METHODS: Between August 1999 and February 2023, 11 patients aged between 64 and 79 years developed LVFWR after acute myocardial infarction (mean interval, 3.5 days). Three patients had active bleeding (blowout-type LVFWR), and the other 8 patients experienced the oozing or sealed state. Eight patients were treated using a sutureless technique with Teflon felt and glue, 2 patients were treated using the primary suture closure technique, and 1 was treated using both the primary suture and the sutureless technique with Teflon felt and glue. RESULTS: One patient died in the operating room as a result of bleeding. Cardiovascular stability and hemostasis were achieved in the other 10 patients. There were 3 early deaths (all 3 cases as a result of area bleeding; 1 was treated with primary suture, 2 with sutureless glue). Three patients received percutaneous coronary intervention before discharge. All 8 remaining patients survived and were discharged. Three patients were lost to follow-up. The follow-up period ranged from 2 to 97 months, with 4 patients exhibiting New York Heart Association class I symptoms and 1 exhibiting New York Heart Association class II symptoms. CONCLUSION: Optimal surgical treatment for postinfarction LVFWR remains controversial. The sutureless technique may be a promising strategy for treating postinfarction LVFWR.


Assuntos
Ruptura Cardíaca Pós-Infarto , Ruptura Cardíaca , Infarto do Miocárdio , Humanos , Lactente , Ruptura Cardíaca Pós-Infarto/diagnóstico , Ruptura Cardíaca Pós-Infarto/etiologia , Ruptura Cardíaca Pós-Infarto/cirurgia , Infarto do Miocárdio/complicações , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/cirurgia , Ruptura Cardíaca/complicações , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/cirurgia , Resultado do Tratamento , Politetrafluoretileno
20.
Retina ; 44(2): 360-363, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37972943

RESUMO

PURPOSE: To report a novel technique for refixation of dislocated CZ70BD intraocular lens (IOL). METHODS: Vitrectomy trocars are placed along the horizontal meridian 5 mm apart. A CV-8 Gore-Tex suture is introduced through a bare sclerotomy into the midvitreous cavity. Under chandelier illumination, a 27 G broad platform forceps is threaded through the eyelet of the dislocated CZ70BD IOL. Using another pair of intraocular forceps, the free intraocular end of the Gore-Tex suture is fed to the broad platform forceps and externalized, thus repositioning the IOL. Particular attention is drawn to pass the suture in an over and under configuration to avoid IOL tilt. An identical procedure is repeated for the other eyelet if the IOL is completely dislocated. The 23 gauge or 25 gauge instruments should not be used for this technique because they do not fit loosely through the eyelets of the IOL. RESULTS: Three eyes were successfully operated on using this technique with at least 6 months of follow-up. There was significant improvement in best-corrected visual acuity after the operation. Postoperative IOL centration and alignment were satisfactory. CONCLUSION: The described surgical technique is effective for transscleral Gore-Tex-assisted refixation of dislocated CZ70BD IOL.


Assuntos
Lentes Intraoculares , Humanos , Implante de Lente Intraocular/métodos , Acuidade Visual , Politetrafluoretileno , Esclera/cirurgia , Suturas , Técnicas de Sutura , Estudos Retrospectivos
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