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1.
Materials (Basel) ; 17(13)2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38998134

RESUMO

Polytetrafluoroethylene (PTFE) is prized for its unique properties in electrical applications, but its natural hydrophobicity poses challenges as it repels water and can cause electrical short circuits, shortening equipment lifespan. In this work, the mentioned issue has been tackled by using two different fluorinated compounds, such as perfluorooctanoic acid (PFOA)/perfluorooctanol (PFOL), along with plasma processing to enhance the surface hydrophilicity (water attraction) of PTFE. This method, demonstrated on Teflon membrane, quickly transformed their surfaces from hydrophobic to hydrophilic in less than 30 s. The treated films achieved a water contact angle saturation of around 80°, indicating a significant increase in water affinity. High-resolution C 1s X-ray photoelectron spectroscopy (XPS) confirmed the formation of new bonds, such as -COOH and -OH, on the surface, responsible for enhanced hydrophilicity. Extended plasma treatment led to further structural changes, evidenced by increased intensity in infrared (IR) and Raman spectra, particularly sensitive to vibrations associated with the C-F bond. Moreover, Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR) showed the formation of surface-linked functional groups, which contributed to the improved water attraction. These findings decisively show that treatment with fluoro-compound along with plasma processing can be considered as a highly effective and rapid method for converting PTFE surfaces from hydrophobic to hydrophilic, facilitating its broader use in various electrical applications.

2.
J Control Release ; 372: 648-660, 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38936743

RESUMO

In vitro-In vivo correlation (IVIVC) is a main focus of the pharmaceutical industry, academia and the regulatory sectors, as this is an effective modelling tool to predict drug product in vivo performance based on in vitro release data and serve as a surrogate for bioequivalence studies, significantly reducing the need for clinical studies. Till now, IVIVCs have not been successfully developed for in situ forming implants due to the significantly different in vitro and in vivo drug release profiles that are typically achieved for these dosage forms. This is not unexpected considering the unique complexity of the drug release mechanisms of these products. Using risperidone in situ forming implants as a model, the current work focuses on: 1) identification of critical attributes of in vitro release testing methods that may contribute to differences in in vitro and in vivo drug release from in situ forming implants; and 2) optimization of the in vitro release method, with the aim of developing Level A IVIVCs for risperidone implants. Dissolution methods based on a novel Teflon shape controlling adapter along with a water non-dissolvable glass fiber membrane (GF/F) instead of a water dissolvable PVA film (named as GF/F-Teflon adapter and PVA-Teflon adapter, respectively), and an in-house fabricated Glass slide adapter were used to investigate the impact of: the surface-to-volume ratio, water uptake ratio, phase separation rate (measured by NMP release in 24 h post injection in vitro or in vivo), and mechanical pressure on the drug release patterns. The surface-to-volume ratio and water uptake were shown to be more critical in vitro release testing method attributes compared to the phase separation rate and mechanical pressure. The Glass slide adapter-based dissolution method, which allowed for the formation of depots with bio-mimicking surface-to-volume ratios and sufficient water uptake, has the ability to generate bio-relevant degradation profiles as well as in vitro release profiles for risperidone implants. For the first time, a Level A IVIVC (rabbit model) has been successfully developed for in situ forming implants. Release data for implant formulations with slightly different PLGA molecular weights (MWs) were used to develop the IVIVC. The predictability of the model passed external validation using the reference listed drug (RLD), Perseris®. IVIVC could not be developed when formulations with different PLGA molar ratios of lactic acid to glycolic acid (L/G) were included. The present work provides a comprehensive understanding of the impact of the testing method attributes on drug release from in situ forming implants, which is a valuable practice for level A IVIVC development.

3.
J Chromatogr A ; 1730: 465115, 2024 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-38936166

RESUMO

Introduced here is the on-line coupling of hollow-fiber flow field-flow fractionation (HF5) to depolarized multi-angle static light scattering (D-MALS). HF5 is a size-based separation alternative to size-exclusion and hydrodynamic chromatography and asymmetric flow field-flow fractionation. HF5 can separate larger sizes than its chromatographic counterparts and provides several advantages over its fractionation counterpart, including reduced sample consumption and greater ease of operation. D-MALS is a variant of MALS in which the depolarized scattering from the analyte solution is measured at a variety of angles simultaneously. Measurements of depolarized scattering have previously been employed in studying the optical properties of solutions or suspensions, to determine the length of rod-like analytes, and to gain increased accuracy in the determination of analyte molar mass. The coupling HF5/D-MALS allows for the depolarization ratio of a solution or suspension to be measured continuously across the fractogram. This is demonstrated here for a Teflon latex the size range of which extends beyond that accessible to commercial size-exclusion columns. The results presented provide the first reported on-line HF5/D-MALS coupling, showing the feasibility of the technique as well as its realized potential for providing continuous depolarization measurements, inter alia.

4.
Acta Neurochir (Wien) ; 166(1): 239, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38814504

RESUMO

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.


Assuntos
Espasmo Hemifacial , Cirurgia de Descompressão Microvascular , Politetrafluoretileno , Humanos , Espasmo Hemifacial/cirurgia , Cirurgia de Descompressão Microvascular/métodos , Nervo Facial/cirurgia , Craniotomia/métodos , Endoscopia/métodos , Neuroendoscopia/métodos , Microcirurgia/métodos , Feminino , Pessoa de Meia-Idade , Masculino
5.
Biol Proced Online ; 26(1): 7, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38504200

RESUMO

BACKGROUND: Osteoclasts are the tissue-specific macrophage population of the bone and unique in their bone-resorbing activity. Hence, they are fundamental for bone physiology in health and disease. However, efficient protocols for the isolation and study of primary human osteoclasts are scarce. In this study, we aimed to establish a protocol, which enables the efficient differentiation of functional human osteoclasts from monocytes. RESULTS: Human monocytes were isolated through a double-density gradient from donor blood. Compared to standard differentiation schemes in polystyrene cell culture dishes, the yield of multinuclear osteoclasts was significantly increased upon initial differentiation of monocytes to macrophages in fluorinated ethylene propylene (FEP) Teflon bags. This initial differentiation phase was then followed by the development of terminal osteoclasts by addition of Receptor Activator of NF-κB Ligand (RANKL). High concentrations of RANKL and Macrophage colony-stimulating factor (M-CSF) as well as an intermediate cell density further supported efficient cell differentiation. The generated cells were highly positive for CD45, CD14 as well as the osteoclast markers CD51/ITGAV and Cathepsin K/CTSK, thus identifying them as osteoclasts. The bone resorption of the osteoclasts was significantly increased when the cells were differentiated from macrophages derived from Teflon bags compared to macrophages derived from conventional cell culture plates. CONCLUSION: Our study has established a novel protocol for the isolation of primary human osteoclasts that improves osteoclastogenesis in comparison to the conventionally used cultivation approach.

6.
Surgeon ; 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38395646

RESUMO

INTRODUCTION: "Subureteric Teflon INGection" (STING) of polytetrafluoroethylene (PTFE/polytef) paste to treat vesicoureteral reflux (VUR) in children was popularised in 1984. It was later abandoned as an implantation material because of the possibility of migration from the injection site. Giant-cell foreign-body granuloma to Polytef in the bladder is a rare cause of ureteric obstruction. Only a handful of cases have been reported in the literature. METHODS: We performed a prospective analysis of a series of 6 adult patients who had childhood STING and presented with foreign-body granuloma to Polytef in the bladder. We report their clinical presentation, findings and treatment. RESULTS: 1 male and 5 females with a history of STING procedure in childhood for VUR presented in later life with foreign-body granuloma to Polytef. The median age at first STING procedure and at presentation to the Urology Department was 3 and 34 years respectively. The most common clinical presentations were flank pain and urinary tract infection (UTI) and all patients had radiological findings of calcified lesions at the vesicoureteric junction(s). 4 patients had histological findings of giant-cell foreign-body granuloma. 4 patients required definitive ureteric reimplantation. CONCLUSION: Polytef granuloma causing distal ureteric obstruction may give rise to significant morbidity and renal damage. Due to the likelihood of progression of the granuloma, excision and ureteric reimplantation is considered the standard approach in the management of patients with viable kidneys. LEVEL OF EVIDENCE: Level 5.

7.
ACS Appl Mater Interfaces ; 16(7): 9544-9550, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38346935

RESUMO

Quantum dot light-emitting diodes (QLEDs) have attracted increasing attention due to their excellent electroluminescent properties and compatibility with inkjet printing processes, which show great potential in applications of pixelated displays. However, the relatively low resolution of the inkjet printing technology limits its further development. In this paper, high-resolution QLEDs were successfully fabricated by electrohydrodynamic (EHD) printing. A pixelated quantum dot (QD) emission layer was formed by printing an insulating Teflon mesh on a spin-coated QD layer. The patterned QLEDs show a high resolution of 2540 pixels per inch (PPI), with a maximum external quantum efficiency (EQE) of 20.29% and brightness of 35816 cd/m2. To further demonstrate its potential in full-color display, the fabrication process for the QD layer was changed from spin-coating to EHD printing. The as-printed Teflon effectively blocked direct contact between the hole transport layer and the electron transport layer, thus preventing leakage currents. As a result, the device showed a resolution of 1692 PPI with a maximum EQE of 15.40%. To the best of our knowledge, these results represent the highest resolution and efficiency of pixelated QLEDs using inkjet printing or EHD printing, which demonstrates its huge potential in the application of high-resolution full-color displays.

8.
JSES Int ; 7(6): 2379-2388, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37969513

RESUMO

Background: The graft material generally used in superior capsular reconstruction (SCR) may be a human dermal allograft or an autologous tensor fascia lata (TFL) graft. According to a previous biomechanical study, a dermal graft (3 mm) was found to be insufficient and a thicker and stiffer graft was required. However, graft-site mobility should be considered when harvesting TFL, especially in the elderly. We have used Teflon felt as a graft material for SCR in the elderly for pain relief. This study aimed to compare the pain-relieving effects and clinical outcomes between Teflon felt and TFL graft. Methods: This study included 39 patients (Teflon felt group: 19 patients, TFL group: 20 patients) who underwent SCR with a minimum of 2-year follow-up. Patients with painful irreparable rotator cuff tears but with shoulder elevation (abduction or flexion) of at least 130° were included in the study. Shoulder range of motion, acromiohumeral distance, and the numerical rating scale were evaluated preoperatively and 2 years postoperatively. Results: There were no significant differences between the Teflon felt and TFL groups in terms of shoulder elevation (151 ± 33° vs. 164 ± 15°, P = .57), acromiohumeral distance (8.3 ± 2.2 mm vs. 7.5 ± 2.5 mm, P = .14), and numerical rating scale (1.0 ± 1.2 vs. 0.9 ± 0.8, P = .93). Conclusion: SCR with Teflon graft provided pain relief equivalent to TFL graft. It may be an effective treatment option in elderly patients for irreparable rotator cuff tears with respect to pain relief.

9.
Acta Neurochir (Wien) ; 165(12): 3877-3885, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37955684

RESUMO

OBJECTIVE: Microvascular decompression (MVD) is a well-accepted treatment modality for trigeminal neuralgia (TN) with high initial success rates. The causes for recurrence of TN after previously successful MVD have not been fully clarified, and its treatment is still a matter of debate. Here, we present the surgical findings and the clinical outcome of patients with recurrent TN after MVD who underwent posterior fossa re-exploration. METHODS: Microsurgical posterior fossa re-exploration was performed in 26 patients with recurrent TN (mean age 59.1 years) who underwent MVD over a period of 10 years. The trigeminal nerve was exposed, and possible factors for recurrent TN were identified. Arachnoid scars and Teflon granulomas were dissected meticulously without manipulating the trigeminal nerve. Outcome of posterior fossa re-exploration was graded according to the Barrow Neurological Institute (BNI) pain intensity score. Follow-up was analyzed postoperatively at 3, 12, and 24 months and at the latest available time point for long-term outcome. RESULTS: The mean duration of recurrent TN after the first MVD was 20 months. Pain relief was achieved in all patients with recurrent TN on the first postoperative day. Intraoperative findings were as follows: arachnoid scar tissue in 22/26 (84.6%) patients, arterial compression in 1/26 (3.8%), venous contact in 8/26 (30.8%), Teflon granuloma in 14/26 (53.8%), compression by an electrode in Meckel's cave used for treatment of neuropathic pain in 1/26 (3.8%), evidence of pulsations transmitted to the trigeminal nerve through the Teflon inserted previously/scar tissue ("piston effect") in 15/26 (57.7%), and combination of findings in 18/26 (69.2%). At long-term follow-up (mean 79.5 months; range, 29-184 months), 21/26 (80.8%) patients had favorable outcome (BNI I-IIIa). New hypaesthesia secondary to microsurgical posterior fossa re-exploration occurred in 5/26 (19.2%) patients. CONCLUSIONS: Posterior fossa re-exploration avoiding manipulation to the trigeminal nerve, such as pinching or combing, may be a useful treatment option for recurrent TN after previously successful MVD providing pain relief in the majority of patients with a low rate of new hypaesthesia.


Assuntos
Cirurgia de Descompressão Microvascular , Neuralgia do Trigêmeo , Humanos , Pessoa de Meia-Idade , Neuralgia do Trigêmeo/etiologia , Neuralgia do Trigêmeo/cirurgia , Cirurgia de Descompressão Microvascular/efeitos adversos , Cicatriz , Recidiva Local de Neoplasia/cirurgia , Dor/cirurgia , Politetrafluoretileno , Resultado do Tratamento , Estudos Retrospectivos
10.
J Clin Med ; 12(7)2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37048790

RESUMO

BACKGROUND: Superior capsular reconstruction (SCR) for massive, irreparable rotator cuff tears involves anchoring a graft between the superior glenoid and the greater tuberosity of the humerus. Optimizing the graft size is important. We aimed (1) to evaluate the reliability of plain film radiography in determining graft size for SCR and (2) to create a database to help predict future graft sizes. METHODS: An inter- and intra-rater reliability trial was conducted on 10 and 6 subjects with healthy shoulders, respectively, using plain film radiography to measure the distance between the superior glenoid and the supraspinatus footprint. The subjects were positioned upright with an abduction pillow modified to hold the shoulder at 30° abduction and 45° external rotation, afterwhich a true antero-posterior shoulder radiograph was captured. Thirty subjects were recruited for the database and grouped using the aforementioned protocol. RESULTS: The inter-rater and intra-rater trial agreement was excellent, with intraclass correlation coefficients of 0.94 (95% CI) and 0.76 (95% CI), respectively. Three medio-lateral patch sizes, of 33 mm, 38 mm, and 47 mm, were proposed based on the protocol in 30 subjects. CONCLUSIONS: Plain film radiography demonstrated excellent reliability in measuring the distance between the superior glenoid and the supraspinatus footprint. Three ordinal patch sizes are proposed.

11.
Environ Sci Pollut Res Int ; 30(8): 21360-21367, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36266595

RESUMO

It has been widely postulated that thermal degradation of polytetrafluoroethylene (PTFE; commercially known as Teflon) under the presence of moisture presents a likely source for the formation of the notorious perfluorocarboxylic acids (CF3(CF2)nCO(OH) PFCAs) and perfluorinated aldehydes (CF3(CF2)nCO(F/H). Thus, deployment of objects laden with Teflon at the peak of their thermal stability may contribute to the atmospheric budget of PFCAs. However, the underlying mechanism remains largely speculative. This study reports potential energy surfaces for reactions that govern oxidative transformation of n-C8F18 (as a model compound of PTFE) into tridecafluoroheptanoyl fluoride and perfluoroheptanoic acid. Central to computed pathways are dissociative addition reactions of water over the carbonyl group and elimination of hydroperoxyl radicals. Facile activation enthalpies are encountered in the involved steps. Our analysis discloses that formation of the building monomer C2F4 should be suppressed under thermolysis oxidation conditions at which synthesis of trifluoroacetic acids is preferred. Constructed kinetic model illustrates a near-complete conversion of the PTFE model compound into perfluorocarboxylic acids (CF3(CF2)nCO(OH) and perfluorinated aldehydes. Outcomes from this study should be instrumental in providing a better understanding of the likely contribution of fluoropolymers in the observed environmental loads of perfluorocarboxylic acids.


Assuntos
Fluorocarbonos , Politetrafluoretileno , Fluorocarbonos/análise , Polímeros de Fluorcarboneto/metabolismo , Ácidos , Oxirredução , Água , Ácidos Carboxílicos
12.
J Pharm Sci ; 112(3): 700-707, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36150468

RESUMO

The biocompatibility and effects on cells' bioactivity of developed pharmaceuticals are crucial properties, required to permit their safe delivery. Nanogel matrices offer a promising role in emerging pharmaceutics; however, it is crucial that they and their excipients do not demonstrate detrimental effects on the cells to which they interact. This study investigated the use of Teflon and the secondary bile acid deoxycholic acid in the formation of novel nanogel matrices. Each has properties which may be of benefit for the nanogels created and their use in the pharmaceutical industry. Rheological parameters and scanning electron microscopy studies were conducted. In order to assess the developed nanogels' impacts on cellular bioactivity, studies using Seahorse assays were conducted on three cell types, hepatic, muscle and pancreatic beta cells. Results demonstrated the addition of Teflon did not alter the morphological characteristics of resulting nanogels or the metabolic profiles of the cell lines. Interestingly, pancreatic beta cells highlighted the potential of Teflon to exert a protective profile from mitochondrial damage. Overall, the developed nanogels showed potentially promising profiles in certain studies conducted which may lead to future research.


Assuntos
Polietilenoglicóis , Politetrafluoretileno , Nanogéis , Polietilenoimina
13.
Front Surg ; 9: 904434, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36570809

RESUMO

Trigeminal Neuralgia is commonly triggered by stimuli in the area of the trigeminal nerve innervation. We report an exceptionally rare case of a 61-year-old woman who complained of recurrent trigeminal neuralgia, which sole trigger was seeing a bright light. Teflon felt that was placed on the nerve root in the initial surgery was suspected of causing this rare type of trigeminal neuralgia. A reflex circuit linking luminance to trigeminal nerve activity may be implicated in activating a trigeminal nociceptive pathway by a bright light trigger.

14.
Polymers (Basel) ; 14(22)2022 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-36433009

RESUMO

The bacterial contamination of cutting boards and other equipment in the meat processing industry is one of the key reasons for reducing the shelf life and consumer properties of products. There are two ways to solve this problem. The first option is to create coatings with increased strength in order to prevent the formation of micro damages that are favorable for bacterial growth. The second possibility is to create materials with antimicrobial properties. The use of polytetrafluoroethylene (PTFE) coatings with the addition of metal oxide nanoparticles will allow to the achieving of both strength and bacteriostatic effects at the same time. In the present study, a new coating based on PTFE and Fe2O3 nanoparticles was developed. Fe2O3 nanoparticles were synthesized by laser ablation in water and transferred into acetone using the developed procedures. An acetone-based colloidal solution was mixed with a PTFE-based varnish. Composites with concentrations of Fe2O3 nanoparticles from 0.001-0.1% were synthesized. We studied the effect of the obtained material on the generation of ROS (hydrogen peroxide and hydroxyl radicals), 8-oxoguanine, and long-lived active forms of proteins. It was found that PTFE did not affect the generation of all the studied compounds, and the addition of Fe2O3 nanoparticles increased the generation of H2O2 and hydroxyl radicals by up to 6 and 7 times, respectively. The generation of 8-oxoguanine and long-lived reactive protein species in the presence of PTFE/Fe2O3 NPs at 0.1% increased by 2 and 3 times, respectively. The bacteriostatic and cytotoxic effects of the developed material were studied. PTFE with the addition of Fe2O3 nanoparticles, at a concentration of 0.001% or more, inhibited the growth of E. coli by 2-5 times compared to the control or PTFE without NPs. At the same time, PTFE, even with the addition of 0.1% Fe2O3 nanoparticles, did not significantly impact the survival of eukaryotic cells. It was assumed that the resulting composite material could be used to cover cutting boards and other polymeric surfaces in the meat processing industry.

15.
Clin Case Rep ; 10(11): e6612, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36415719

RESUMO

Teflon has been proved to be able to extravasate and infiltrate into soft tissue to form an inflammatory giant-cell foreign-body reaction, a so-called Teflon granuloma. We present a rare case report of a patient with two Teflon granulomas of the head and neck, who were first interpreted as a neoplasm.

16.
Neurol India ; 70(4): 1412-1416, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36076637

RESUMO

Background: Microvascular decompression (MVD) of the trigeminal nerve is a well-accepted nondestructive procedure for trigeminal neuralgia. Usually, Teflon (PTFE) puff or felt graft techniques, which are most commonly used, are associated with arachnoiditis and recurrence among other complications. We use the "sleeve graft" technique using PTFE to separate the neurovascular conflict and here we describe our experience with the same in 376 cases. Objectives: To study the outcomes in 376 patients treated with sleeve graft technique for trigeminal neuralgia. Materials and Methods: For a period of 18 years, from 2002 to 2020, all cases of medically refractory trigeminal neuralgia were subjected to the "sleeve graft" technique for MVD. Pre- and post-operatively, pain score was given according to Barrow Neurological Institute pain intensity score. Cases were observed for any complications and pain relief in short and long-term follow-up. Results: In total, 376 cases of refractory primary trigeminal neuralgia cases, among which 198 patients underwent MVD with no prior intervention, 158 underwent MVD following percutaneous ablative procedure, 13 were "Revision MVD" previously done at other centers, and four were post gamma knife failure. There was no incidence of arachnoiditis or recurrence of symptoms. Further, 368 (97.8%) patients had complete recovery from symptoms while eight (2.2%) had partial recovery after 5 years of follow-up. Complications included hearing loss (n = 1), temporary hypoesthesia (n = 45), and permanent hypoesthesia (n = 7). Conclusion: "PTFE Sleeve Graft" technique to remove the neurovascular conflict in micro vascular decompression (MVD) for trigeminal neuralgia is a safe and effective technique that yields better results.


Assuntos
Aracnoidite , Cirurgia de Descompressão Microvascular , Neuralgia do Trigêmeo , Aracnoidite/complicações , Descompressão , Humanos , Hipestesia , Cirurgia de Descompressão Microvascular/métodos , Dor/etiologia , Politetrafluoretileno , Estudos Retrospectivos , Resultado do Tratamento , Neuralgia do Trigêmeo/etiologia , Neuralgia do Trigêmeo/cirurgia
17.
Brachytherapy ; 21(6): 754-763, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36088225

RESUMO

PURPOSE: To design the different Polytetrafluoroethylene (PTFE) based flexible implant tubes using an in-house developed device and to evaluate them for High dose rate (HDR) interstitial brachytherapy using computer tomography images. METHODS AND MATERIALS: PTFE hollow tube having a 2 mm (6 French) outer diameter (OD) and 1.4 mm inner diameter (ID) was used to design in-house single and/or double leader flexible catheters for interstitial brachytherapy implant. An in-house Plastic Wire Drawing Plate (PWDP) machine was developed. Customization of PTFE hollow flexible implant tube (FIT) was done through PWDP. Different percentages of BaSO4 (5%, 10%, & 15%) were added to Nylon 6 to make radiopaque button. Various quality assurance tests were performed with the PTFE tubes implanted in the brinjal (phantom) before using them on the patients. That is, coupling of brachytherapy machine transfer tube with flexible PTFE Tubes, CT scan artifacts, tube kinks, breast template, and free-hand compatibility. RESULTS: With the help of the PWDP machine, plastic wires of different lengths were made for single leader and double leader tubes. The different plastic leader ends of 1 cm to 50 cm lengths having 1 mm diameter were created. The radiopaque button of Nylon 6 in circular shape having 1 cm diameter and 0.5 cm thick was created. Developed radiopaque buttons were visible on CT scan images as well as on radiograph images. CONCLUSIONS: PTFE tubes of the desired length can be made depending upon the size of the brachytherapy implant and are inexpensive than commercially available flexible implant tubes.


Assuntos
Braquiterapia , Humanos , Braquiterapia/métodos , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Politetrafluoretileno , Imagens de Fantasmas
18.
Front Bioeng Biotechnol ; 10: 959512, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36091432

RESUMO

Implanted biomaterials elicit an immune-mediated foreign body reaction (FBR) that results in the fibrous encapsulation of the implant and can critically impact the performance of some implants. Consequently, understanding the molecular mechanisms that underpin cell-materials interactions that initiate biomaterial-induced inflammation and fibrosis is critical to improving the performance of biomaterial implants negatively impacted by the FBR. Damage-associated molecular patterns (DAMPs) are endogenous mediators of inflammation that are released upon tissue injury and induce sterile inflammation via Toll-like receptors (TLRs). However, the prevalence of DAMPs within the adsorbed protein layer on material surfaces and their role mediating cell-material interactions is unclear. Previously, our group demonstrated that molecules in fibroblast lysates adsorbed to various biomaterials and induced a potent TLR2-dependent inflammatory response in macrophages at 24 h. In this study, we examined the extended response of RAW-Blue reporter macrophages on lysate or serum-adsorbed Teflon™ AF surfaces to understand the potential role of adsorbed DAMPs in macrophage-material interactions at later time points. Lysate-conditioned surfaces maintained increased nuclear factor kappa B (NF-κB) and activator protein 1 (AP-1) transcription factor activity and increased expression Regulated upon Activation, Normal T Cell Expressed and Presumably Secreted (RANTES/CCL5) at 72 h and 120 h, compared to FBS-conditioned surfaces. In contrast, monocyte chemoattractant protein 1 (MCP-1/CCL2) was only elevated at 72 h in lysate conditions. Transforming growth factor beta 1 (TGF-ß1) secretion was significantly increased on lysate-conditioned surfaces, while conditioned media from macrophages on lysate-conditioned surfaces induced alpha smooth muscle actin (αSMA) expression in 3T3 fibroblasts. TLR2 neutralizing antibody treatment significantly decreased NF-κB/AP-1 activity and attenuated TGF-ß1 expression at both time points, and MCP-1 and RANTES at 72 h. Finally, multinucleated cells were observed on lysate-conditioned surfaces at 72 h, indicating adsorbed DAMPs induced a fusion permissive environment for adherent macrophages. This study demonstrates that adsorbed DAMPs continue to influence macrophage-material responses beyond the initial 24-h period and maintain a pro-inflammatory and fibrotic response that models aspects of the early FBR. Furthermore, the transient inhibition of TLR2 continued to exert an effect at these later time points, suggesting TLR2 may be a target for therapeutic interventions in FBR.

19.
J Environ Manage ; 319: 115749, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-35982559

RESUMO

Filter based PM2.5 samples are typically used to measure its chemical constituents. Such measurements are made in dense sampling networks to assess regulatory compliance and for source apportionment. Thus, quantifying sampling artefacts is crucial. In this study, 24-h integrated PM2.5 samples collected over Bhopal, India a COALESCE (CarbOnaceous AerosoL Emissions, Source apportionment and ClimatE impacts) site during 2019 and 2020, were used to estimate particulate organic carbon (OC) artefacts. Total OC and its thermal fractions (OC1, OC2, OC3, and OC4) measured on 349 bare quartz (Q) and QbQ filters each, were used to determine OC positive artefacts on quartz filters. 50 QbT (Quartz behind Teflon) filters in conjunction with the simultaneous QbQ samples (a subset of the total QbQ) were used to estimate OC volatilization from Teflon filters. On average, adsorbed gaseous OC contributed 17% and 11% to the measured total OC during 2019 and 2020, respectively. Further, the volatilization loss of organics from Teflon filter (used to quantify PM2.5 mass) ranged between 7% and 9%, and 5% and 6% of the PM2.5 mass during 2019 and 2020, respectively. The results of this study provide the first systematic long-term evaluation of thermal carbon fraction-wise sampling artefacts, estimates of organic volatilization losses from Teflon filters and their implications to PM2.5 mass closure, over a regionally representative location in India.


Assuntos
Poluentes Atmosféricos , Aerossóis/análise , Poluentes Atmosféricos/análise , Artefatos , Carbono/análise , Monitoramento Ambiental/métodos , Tamanho da Partícula , Material Particulado/análise , Politetrafluoretileno , Quartzo , Estações do Ano
20.
Indian J Otolaryngol Head Neck Surg ; 74(Suppl 1): 511-516, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36032831

RESUMO

Chronic Otitis Media is the most common cause of hearing impairment with ear discharge with which patients report to any otologist. The aim of management in such cases is to provide a safe ear and restore the hearing by Tympanoplasty. Many materials have been used for ossicular reconstruction, including both biological and synthetic materials. Minimally destroyed ossicle can be utilized for Ossiculoplasty while in case of complete destruction of ossicles, synthetic materials may be used such as teflon, titanium, hydroxyapatite etc. To evaluate the outcome of Ossiculoplasty using autograft versus synthetic graft. A prospective study done using non-probability convenience method of sampling involving a group of 50 patients were subjected to Tympanoplasty with Ossiculoplasty. Intra operative decision was taken on the type of graft to be used for Ossiculoplasty and the patients were divided into two equal groups, A (autograft) and B (synthetic graft) of 25 each. The patients were thereafter evaluated post surgery at periodic intervals of 3, 6 and 12 months. The improvement in hearing following surgery was significant (AB gap < 20 dB) in the range of 72% in Group A to 84% in Group B of patients 12 months after surgery. Also there was a 37% change in AC in Group A as compared to 40% in Group B, demonstrating marginally better improvement in hearing with synthetic graft as compared to autograft. The patients have significant improvement in hearing thresholds after ossiculoplasty with both autograft and synthetic graft. Teflon is an excellent alternative for ossiculoplasty when autologous incus is not available for use due to disease.

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