Use of X-Ray Photoelectron Spectroscopy as an analytical tool for the study of contamination by Teflon in the synthesis of Mo(VI)Cl2O2Bipy/ TiO2 catalysts

The preparation of catalysts can involve various sources of contamination, which can seriously affect the quality of the prepared materials. In the present work, a case of fluorine contamination in a set of catalyst samples was studied, in which using the X-Ray Photoelectron Spectroscopy (XPS) technique, it was evidenced by the F 1s signal that this element was present in the form of Teflon, since its binding energy corresponded mainly to the CF2 species. Furthermore, using the C 1s signal, it was also possible to corroborate the presence of the CF2 group, which is associated with the main component of the Teflon carbon chains. The use of this information made it possible to identify that the solvent dehydration procedure (previous step to obtaining the catalysts) could lead to contamination with Teflon since it involved various accessories with Teflon, organic solvents and high temperature; the Teflon tape and the magnetic stirrer being the possible sources of contamination.

La preparación de catalizadores puede contener diversas fuentes de contaminación, las cuales pueden afectar seriamente las propiedades de los materiales preparados. En este artículo se estudió un caso de contaminación con flúor en una serie de muestras de catalizadores. Empleando la técnica de espectroscopia fotoelectrónica de rayos X (XPS) se evidenció la presencia de flúor en la superficie de los materiales, el cual estaba asociado al polímero teflón, ya que su energía de enlace correspondía principalmente con la de la especie CF2. Además, empleando la señal C 1s, se logró corroborar la presencia de la especie CF2, el cual está asociado al componente principal de las cadenas carbonadas de teflón. El uso de la información obtenida por XPS permitió determinar que durante la deshidratación del solvente (paso previo para la obtención de los catalizadores en el cual se emplean solventes orgánicos y alta temperatura) se podría estar llevando a cabo la contaminación con teflón, ya que este componente está presente en diversos accesorios empleados en el proceso de deshidratación, siendo la cinta de teflón y el agitador magnético las posibles fuentes de contaminación.

A preparação de catalisadores pode conter diversas fontes de contaminação, as quais podem afeitar seriamente as propriedades dos materiais preparados. No presente trabalho estudou-se um caso de contaminação com flúor numa série de amostras de catalisadores. Usando a técnica da espectroscopia fotoeletrônica de raios X (XPS), evidenciou-se a presença de flúor na superfície dos materiais, o qual estava associado ao polímero Teflon, já que sua energia de ligação correspondia principalmente à da espécie CF2. Além disso, usando a sinal C 1s, foi possível corroborar a presença do grupo CF2, o qual está associado ao componente principal das cadeias carbônicas do Teflon. O uso da informação obtida por XPS permitiu determinar que durante a desidratação do solvente (passo prévio para a obtenção dos catalisadores no qual são usados solventes orgânicos e alta temperatura) tem-se a contaminação com Teflon, já que este componente está presente em diversos acessórios utilizados no processo de desidratação, sendo a fita do Teflon e o agitador magnético as possíveis fontes da contaminação.

Bioglue-Coated Teflon Sling Technique in Microvascular Decompression for Hemifacial Spasm Involving the Vertebral Artery

OBJECTIVE: Microvascular decompression (MVD) for hemifacial spasm (HFS) involving the vertebral artery (VA) can be technically challenging. We investigated the therapeutic effects of a bioglue-coated Teflon sling technique on the VA during MVD in 42 cases. METHODS: A bioglue-coated Teflon sling was crafted by the surgeon and applied to patients in whom neurovascular compression was caused by the VA. The radiologic data, intra-operative findings with detailed introduction of the procedure, and the clinical outcomes of each patient were reviewed and analyzed. RESULTS: The 42 patients included in the analysis consisted of 22 females and 20 males, with an average follow-up duration of 76 months (range 24–132 months). Intraoperative investigation revealed that an artery other than the VA was responsible for the neurovascular compression in all cases : posterior inferior cerebellar artery (PICA) in 23 patients (54.7%) and anterior inferior cerebellar artery (AICA) in 11 patients (26.2%). All patients became symptom-free after MVD. Neither recurrence nor postoperative neurological deficit was noted during the 2-year follow-up, except in one patient who developed permanent deafness. Cerebrospinal fluid (CSF) leak occurred in three patients, and one required dural repair. CONCLUSION: Transposition of the VA using a bioglue-coated Teflon sling is a safe and effective surgical technique for HFS involving the VA. A future prospective study to compare clinical outcomes between groups with and without use of this novel technique is required.

A Case of Chemical Pneumonitis Induced by Teflon Inhalation / 대한내과학회지

Chemical pneumonitis is defined as lung irritation caused by inhalation of substances toxic to the lungs. Acute chemical pneumonitis causes swelling of the lung tissue, movement of fluid into the air spaces in the lung, and a decreased ability to absorb oxygen and eliminate carbon dioxide. Teflon (polytetrafluoroethylene) is a commonly used synthetic fiber or insulator. To our knowledge, chemical pneumonitis and acute respiratory failure induced by Teflon inhalation has not been previously reported in Korea. We experienced a 44-year-old patient who had a cough and dyspnea that were aggravated 10 h after smoking tobacco wet by Teflon for 5 min at his workplace. Upon arrival at the emergency room, his blood pressure was low and his arterial blood gas analysis revealed hypoxemia. A chest radiograph showed diffuse haziness on both mid- to-lower lung fields. Following treatment by conservative therapy, including oxygen supply and steroid use, his condition was relatively good and his chest radiograph normalized.

Hemolytic Anemia Associated with a Teflon Felt Strip on a Proximal Anastomotic Site for Aortic Replacement in a Patient with Aortic Dissection / 日本心臓血管外科学会雑誌

A 61-year-old man was referred to our hospital for treatment of hemolytic anemia after ascending aortic replacement aortic dissection. Cine mode magnetic resonance imaging (MRI) showed stenosis at the proximal anastomostic site of a Teflon strip. We diagnosed hemolytic anemia induced by collision of red blood cells on the inverted felt strip. Conservative therapy with Sarpogrelate and β-blockers was effective to treat his hemolytic anemia. However, 7 years later he was re-admitted because of infective endocarditis at the aortic valve, and underwent aortic root replacement. Intraoperative findings showed a stiff and inverted Teflon felt strip causing stenosis of the proximal anastomosis. Hemolytic anemia should be considered a rare complication of using a Teflon felt strip to reinforce anastomosis for acute aortic dissection.

O efeito teflon e o copy-paste na prevenção / The Teflon Effect and Copy-Paste in prevention

Fator subclínico de risco é palavra-chave na prevenção. Por isso, a denominação assassina silenciosa da fisiologia, originária da hipertensão arterial sistêmica, é expansível para demais fatores de risco. Em suma, quando se dispõe de armas-preventivas da Medicina e se mentalizam órgãos-alvo do paciente que está saudável, apertar o gatilho faz diferença na visão de oportunidade fisiopatológica, mas o efeito teflon pode funcionar como um colete salva-estilo de vida atual.

LiF TLD in TLD Holder for In Vivo Dosimetry / 대한방사선종양학회지

PURPOSE: LiF TLD has a problem to be used in vivo dosimetry because of the toxic property of LiF. The aim of this study is to develop new dosimeter with LiF TLD to be used in vivo dosimetry. MATERIALS AND METHODS: We designed and manufactured the teflon box(here after TLD holder) to put TLD in. The external size of TLD holder is 4x4x1 mm3. To estimate the effect of TLD holder on TLD response for radiation, the linearity of TLD response to nominal dose were measured for TLD in TLD holder. Measurement were performed in the 10 MV x-ray beam with LiF TLD using a solid water phantom at SSD of 100 cm. Percent Depth Dose (PDD) and Tissue-Maximum Ratio (TMR) with varying phantom thickness on TLD were measured to find the effect of TLD holder on the dose coefficient used for dose calculation in radiation therapy. RESULTS: The linearity of response of TLD in TLD holder to the nominal dose was improved than TLD only used as dosimeter. And in various measurement conditions, it makes a marginnal difference between TLD in TLD holder and TLD only in their responses. CONCLUSION: It was proven that the TLD in TLD holder as a new dosimetry could be used in vivo dosimetry.

Effect of Teflon Membrane and Nylon Membrane on Guided Bone Regeneraton in Rabbit Tibia

The purpose of present study is comparing the effect of Teflon Membrane and Nylon Membrane on bone regeneration in rabbit tibia. The 6 defects of 8x8x5mm size were drilled with dental handpiece in rabbit tibia, which on left side as an order of Control group(no coverage), Group 1(Nylon 5 micrometer size), Group 3(Nylon 10 micrometer size), and on right side Control group, Group 2(5 micrometer Teflon), Group 4(10 micrometer Teflon). Animals were killed at 7, 10, 14, 42 days to make specimens and observed the difference of healing potentials with light microscopy. The results were as follows ; 1. New bone formation has taken place at 14 days in Guided Bone Regeneration (GBR) group comparing to the Control group of massive inflammatory status. 2. Larger pore membrane allows more favorable healing potentials. Bone formation started earlier in larger membrane pore groups than smaller groups, until 14 days. 3. Bone forming potentials of Teflon membrane group was higher than Nylon membrane groups, Control group has the lowest bone forming potentials. 4. New bone formation was almost ended in 42 days, and there was no difference of bone formation between Nylon and Teflon membrane group of different size. There was no difference of bone formation at final stage(42 days) between Nylon membrane and Teflon membrane of same pore size. So nylon membrane may be clinically usable in guided bone regeneration case with further studies.

Netting Operation to Control the Neurofibroma on Face

When the facial neurofibroma is involved with craniofacial skeleton and causes dysplastic bony anomaly, the deformity or the defect can be corrected by craniofacial surgery. However, it is impossible to radically remove all the involved facial soft tissues and facial nerve. Therefore, the partial excision may cause recurrence of the disease and thus result in the deformity of facial soft tissue because of the persisting force of gravity. We used Teflon mesh as replacement material for destroyed subcutaneous tissue or substitute for superficial fascia damaged by tumor infiltration. This method enables to prevent the deformity of facial soft tissue caused by recurrence and gravity effect after partial excision and to control the tumor growth. We performed suspension into the superio-posterior direction of Teflon mesh like the fish netting procedure after partial excision in attempt to prevent further progress of remnant tumor, thus compressing or capturing remnant neurofibroma. Surgical correction was performed for 8 patients of neurofibroma and all the patients were followed up for 5 or 6 years. According to the results, the Teflon mesh, which is inserted for replacement for subcutaneous tissue or superficial fascia after partial excision of the tumor mass, is well maintained as part of layers of facial structure along with collagen. No tumor proliferation under mesh was observed. Deformity of facial contour caused by recurrence of tumor or gravity effect was not observed. Our method using Teflon mesh for replacement of destroyed subcutaneous tissue and compression on the remnant tumor is considered a proper treatment modality for facial neurofibroma, thus hereby we report our studies with the review of the literature.

The Effect of Microvascular Decompression in Trigeminal Neuralgia and Hemifacial Spasm

OBJECTIVE: Microvascular decompression(MVD) is an effective technique for the patients who have trigeminal neuralgia(TN) and hemifacial spasm(HS). But, the failed MVD cases have been reported in long term follow-up studies. We introduce our unique operative technique in MVD and analyze the effect of MVD through our modified operative technique, offending vessels in operative field, operative complications, and failed cases. PATIENTS AND METHODS: A series of 52 patients with intractable TN(32 cases) or HS(20 cases) were treated by MVD. Other 7 cases of TN were excluded because they were proved to have TNs secondary to other pathologies, such as nasopharyngeal carcionoma, trigeminal schwannoma, epidermoid tumors, postherpetic neuralgia. The follow-up time was from 3 months to 4 years. RESULT: All 52 patients were treated by retromastoid suboccipital approach. 28 patients of TN were treated with MVD only, and the other 4 patients, were treated with selective sensory root squeezing(1 case), partial sensory rhizotomy(PSR)(2 cases), and PSR with MVD(1 case). Among 20 patients of HS were treated with MVD, 3 patients were not relieved after first operation but were free of spasm after reoperation within 1 week. The degree of nerve root compression was classified as compression and contact and the final outcome compared each other. We used our uniquely designed horseshoe-shaped teflon ring to decompress the vessel from the nerve. In TN, the most common offending vessel was superior cerebellar artery(59.4%) and the final outcomes were as follows: excellent, 87.5%(28 cases): good, 3.1%(1 case): poor, 9.4%(3 cases). In HS, the most common offending vessel was anterior inferior cerebellar artery(55%) and the final outcomes were as follows: excellent, 85%(17 cases): good, 5%(1 case): poor, 10%(2 cases). CONCLUSION: In compressed group, the cure rate was 100%. However, in contact group the cure rate were 81.3% in TN and 75% in HS. RESULT: From the review of the literatures in failed MVD, the etiologies most commonly reported were inadequate decompression, new vessel compression, adhesion and lysis of prosthesis. Our specially designed horseshoe-shaped teflon ring has some advantages to prevent recurrence of symptom by dislodging or slippage of prosthesis or recompression by other vessels. The overall result of our unique MVD was excellent in patients with TN(87.5%) and HS(85%).

Pathological Changes of the Blood Vessel Wrapped in Teflon(polytetrafluoroethylene) Felt in the Cat

Teflon(polytetrafluoroethylene) felt it utilized well as an implanted material for suboccipital microvascular decompression of hemifacial spasm, trigeminal neuralgia and glossopharyngeal neuralgia. Although the effect of Teflon has been studied widely, there are no studies about the effect on the cerebral vessels. The authors have examined the porribilities of the change of cat cerebral vessels and femoral vessels by direct contact the Teflon. There was no changes of vessel wall. Also the authors couldn't find any aneurismal changes of vessels wall. Teflon han only effect of foreign body reaction. This experiment shows that Teflon is relatively inert when used for microvascular decompression.

Endoscopic teflon injection in vesicoureteral reflux / 대한비뇨기과학회지

Twenty vesicoureteral reflux patients with 31 reflux renal units were treated with endoscopic Teflon injection. Twenty one reflux renal units were cured and the success rate after first injection was 67.7 %. In 5 more renal units the second injection was done and the refluxes were subsided in all cases. The overall success rate was 83.9 %. Teflon injection was also effective in vesicoureteral reflux with neurogenic bladder. There are many benefits of endoscopic Teflon injection in the treatment of vesicoureteral reflux but long term follow-up is needed and we must consider the possibility or complication especially in child.

Two Cases of Vesicoureteric Reflux Treated by Endoscopic Injection of Teflon / 대한비뇨기과학회지

Primary vesicoureteric reflux is regarded as a congenital condition resulting from a short submucosal ureteral segment and an absence of adequate detrusor support behind the intravesical ureter. Several antireflux operations have been devised, all of which entail opening the bladder and performing a variety of procedures on the ureter. Polytef paste is a sterile, relatively inert, injectable paste, containing polytef, glycerine and polysorbate and polytef is Teflon that has been pyrolysed. Subureteric injection of Teflon is a good substitute for open operation which eliminate vesicoureteric reflux because it is well tolerated, avoids open operation and shortens Hospital day. Herein we report two case of vesicoureteric reflux treated by endoscopic injection of Teflon and review the literatures.