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Sample records for 10-0 polypropylene suture

  1. Suture loosening and ? sterilization of 10-0 nylon

    International Nuclear Information System (INIS)

    The tissue reaction to 10-0 nylon sutures sterilized with ?-rays was compared to the reaction caused by 10-0 nylon thread sterilized with ethylene oxide. In a vascularized cornea more tissue reaction was seen to 10-0 nylon thread sterilized with ?-rays than to sutures sterilized with ethylene oxide gas. (Auth.)

  2. 21 CFR 878.5010 - Nonabsorbable polypropylene surgical suture.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonabsorbable polypropylene surgical suture. 878... Nonabsorbable polypropylene surgical suture. (a) Identification. Nonabsorbable polypropylene surgical suture is... known as polypropylene and is indicated for use in soft tissue approximation. The polypropylene...

  3. COMPARISON OF ABSORBABLE EXTRA LONG TERM POLY HYDROXY BUTYRATE SUTURE VS NON ABSORBABLE (POLYPROPYLENE SUTURE FOR ABDOMINAL WALL CLOSURE

    Directory of Open Access Journals (Sweden)

    Mallikarjun

    2015-07-01

    Full Text Available PURPOSE: The aim of study is to compare Continuous technique with non - absorbable sutures, Interrupted technique with non - absorbable sutures and Continuous technique with slowly absorbable sutures Focusing mainly on incidence of incisional hernias, burst abdomen, wound infections, chronic wound pain, suture sinus, stitch granuloma, time for rectus closure. METHODOLOGY : Study was conducted for a period of one year on 271 randomized patients with primary elective midline laparotomy in our hospital . patients are divided into group I includes 102 patients with continuous technique using non absorbable polypropylene, group II includes 91 patients with interrupted technique using non absorbable polypropylene and group III includes 78 patients with continuous slowly absorbable polyhydroxybutyrate. RESULTS: No significant difference observed in incidence of wound infections and burst abdomen in all the 3 groups but relatively higher incidence of wound infections in noted our hospital. Incidence of stich granuloma suture sinus and chronic wound pain is more with interrupted technique than continuous technique and are more with non - absor bable suture material. CONCLUSION: Incidence of incisional hernias, suture complications like suture sinus, stitch granuloma can be more effectively reduced with slowly absorbable continuous sutures.

  4. Evaluation of endoscopic laser excision of polypropylene mesh/sutures following anti-incontinence procedures.

    LENUS (Irish Health Repository)

    Davis, N F

    2012-11-01

    We reviewed our experience with and outcome of the largest series to our knowledge of patients who underwent endoscopic laser excision of eroded polypropylene mesh or sutures as a complication of previous anti-incontinence procedures.

  5. Polypropylene Suture Versus Skin Staples for Securing Mesh in Lichtenstein Inguinal Hernioplasty

    International Nuclear Information System (INIS)

    Objective: To compare polypropylene suture and skin staples for securing mesh in Lichtenstein inguinal hernioplasty in terms of mean operating time and postoperative pain. Study Design: Randomized clinical trial. Place and Duration of Study: Surgical Ward, Combined Military Hospital, Kharian, from August 2011 to February 2012. Methodology: All individuals fulfilling inclusion criteria underwent elective Lichtenstein inguinal hernioplasty as admitted patients, under spinal anaesthesia and with aseptic measures. In group 1, during the operation, mesh fixation was done with 2/0 polypropylene suture and skin was closed with subcuticular 2/0 polypropylene suture whereas in group 2, the anchorage of mesh was done with skin staples and skin was closed with staples from the same stapler. Mean operative time and postoperative pain, assessed on a visual analog score, were compared between the groups. Results: The overall postoperative pain was lower (p = 0.026) when staples were used to anchor mesh. Moreover, operative time was also lower (37.42 A +- 2.69 minutes) in staple group versus (42.44 A +- 2.55 minutes in polypropylene group). Conclusion: Mean operating time and postoperative pain is less in securing mesh with skin staples as compared to polypropylene suture in Lichtenstein inguinal hernioplasty. (author)

  6. Polypropylene

    International Nuclear Information System (INIS)

    This book gives description of polypropylene with history, polypropylene chemistry such as polymerization reaction and manufacture method of polypropylene, structure and property of polypropylene like molecular weight, melt flow index and property of inter polymer, property of polypropylene the position of polypropylene among plastic and functional property of polypropylene, ageing resistance of polypropylene, processing of polypropylene like injection molding film and type use of polypropylene with using cases.

  7. Gross and Histologic Evaluation of Abdominal Adhesions Associated with Chromic Catgut and Polypropylene Sutured Enteropexies in Dog Evaluación Macroscópica e Histológica de las Adherencias Abdominales Asociadas a Enteropexias Suturadas con Catgut Crómico y Polipropileno en Perros

    OpenAIRE

    J.F. Akinrinmade; A. O. Lawal

    2010-01-01

    The gross and histologic patterns of abdominal adhesions formed by the use of chromic catgut and polypropylene suture materials were evaluated in dogs. Gross and histologic examinations did not reveal significant difference (p>0.05) in the degree of adhesions observed at enteropexy sites in both suture materials. The use of polypropylene with superior suture qualities should be considered instead of chromic catgut for procedures in which adhesion is desired in the dog.Fueron evaluados los pat...

  8. A Prospective Randomized Study Comparing Skin Staples and Polypropylene Sutures for Securing the Mesh in Lichtenstein's Repair

    Directory of Open Access Journals (Sweden)

    Pankaj Shivhare

    2014-06-01

    Results: Mesh fixation with skin staples is as effective as conventional sutures with the added advantage of significant reduction in the operating time and complications. Conclusions: The staples can be applied much more quickly than sutures for fixing the mesh, thus saving the operating time. The infection rate is significantly decreased with staples. The staples are not associated with any significant complications or recurrence. [Arch Clin Exp Surg 2014; 3(3.000: 147-152

  9. Gross and Histologic Evaluation of Abdominal Adhesions Associated with Chromic Catgut and Polypropylene Sutured Enteropexies in Dog Evaluación Macroscópica e Histológica de las Adherencias Abdominales Asociadas a Enteropexias Suturadas con Catgut Crómico y Polipropileno en Perros

    Directory of Open Access Journals (Sweden)

    J. F Akinrinmade

    2010-12-01

    Full Text Available The gross and histologic patterns of abdominal adhesions formed by the use of chromic catgut and polypropylene suture materials were evaluated in dogs. Gross and histologic examinations did not reveal significant difference (p>0.05 in the degree of adhesions observed at enteropexy sites in both suture materials. The use of polypropylene with superior suture qualities should be considered instead of chromic catgut for procedures in which adhesion is desired in the dog.Fueron evaluados los patrones macroscópicos e histológicos de las adherencias abdominales formadas por el uso de catgut crómico y materiales de sutura de polipropileno. Los exámenes macroscópicos e histológicos no revelaron diferencias significativas (p> 0,05 en el grado de adherencias observadas en los sitios de la enteropexia en ambos materiales de sutura. El uso de suturas de polipropileno con mejores cualidades debe ser considerado en lugar del catgut cromado para procedimientos en los que la adherencia en el perro es deseada.

  10. Comparação entre o uso de fio inabsorvível (polipropileno e fio absorvível (poliglactina 910 na fixação de prótese de polipropileno em correção de defeitos músculo-aponeurótico da parede abdominal: estudo experimental em ratos Comparison between fixation of polypropylene mesh with polypropylene suture and polyglactin 910 suture for treatment of muscle-aponeurotic defects of abdominal wall: experimental study in rats

    Directory of Open Access Journals (Sweden)

    Álvaro Gianlupi

    2004-04-01

    Full Text Available OBJETIVO: Comparar a fixação da tela de prolipropileno na correção de defeitos músculo-aponeuróticos da parede abdominal com fio absorvível (poliglactina 910 e fio inabsorvível (polipropileno. MÉTODOS: Oitenta e um ratos machos da linhagem Wistar foram submetidos a ressecção longitudinal de um segmento músculo-aponeurótico e peritoneal (3x2 cm da parede abdominal, seguida por reforço com tela de polipropileno, em forma de ponte sobre a aponeurose. Foram distribuídos em dois grupos de acordo com o fio usado para fixação da tela: grupo poliglactina 910 - fixada com 8 pontos separados e eqüidistantes em forma de "U" com fio 4-0; e grupo polipropileno - fixada com fio 4-0. A pele foi suturada com fio de nylon 4-0. Após 90 dias, os animais foram submetidos à eutanásia e avaliados macroscopicamente, quanto à presença de hérnia e avaliação histológica da reação inflamatória crônica, absorção do fio e percentagem de fibrose pela técnica vídeo-morfométrica assistida por computador. Utilizaram-se as técnicas de coloração de hematoxilina-eosina e picrossírius. RESULTADOS: Não houve diferença estatisticamente significante entre os grupos, quanto à presença de hérnia incisional (p=0,194. Houve maior fibrose no grupo polipropileno pela avaliação histológica de reação inflamatória crônica, o que não foi verificado quando avaliado pela técnica vídeo-morfométrica (p=0,0005. Não houve diferença entre os grupos quando avaliados os gigantócitos, linfócitos e neutrófilos. Houve maior número de macrófagos no grupo polipropileno (p=0,02. Não houve absorção do fio poliglactina 910 após 90 dias. CONCLUSÃO: A fixação de tela de polipropileno pode ser feita com êxito com fios absorvíveis como a poliglactina 910.PURPOSE: The aim of this study is to assess fixation of a polypropylene mesh in the repair of incisional hernias comparing an absorbable (polyglactin 910 suture and an inabsorbable (polypropylene one. METHODS: Eighty-one male rats of the Wistar breed, weighing from 180g to 220g, were submitted to a longitudinally resection of a musculoaponeurotic and peritoneal segment (3x2 cm of the abdominal wall. Reconstruction was performed by reinforcement with polypropylene mesh, overlaid on the aponeurosis. They were distributed in two groups according to the thread used for mesh fixation as follows: (1 polyglactin 910 group, fixed with 8 stitches 4.0 Polyglactin 910 suture; and (2 Polipropylene group, fixed with 4.0 polypropylene suture. The skin suture was performed with 4.0 nylon continuous stitches. After 90 days, animals were sacrificed and submitted to macroscopic evaluation for the presence of hernias. Histologic samples were stained for Hematoxylin-Eosine and Sirius-Red and were assessed for signs of cicatrization such as chronic inflammatory reaction, fibrosis, suture absortion and percentage of fibrosis by computer-assisted video morfometric technic. RESULTS: There was no significant difference between the groups studied in relation to hernia formation (p=0,194. The histologic study showed significant increase of fibrotic reaction in the polipropylene group (p=0,0005, but this finding was not confirmed in the video-morfometric evaluation. Considering chronic inflammatory reaction, there was no difference between groups in relation to giant cells, lymphocytes and neutrophils. However, in the polipropylene group, macrophages were significantly increased (p=0,02. Polyglactin 910 has not been absorved 90 days after the procedure. CONCLUSIONS: The results of this study suggest that the fixation of polipropilene mesh is effective using absorbable sutures in the repair of ventral (incisional hernias.

  11. Polypropylene; Polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2004-12-01

    Basell has signed an agreement with the Saudi Sahara Petrochemical firm for the construction of a polypropylene plant of 450000 t/year at Al-Jubail (Saudi Arabia). This project plans the construction of a propane dehydrogenation unit too. These two units should start at the end of the year 2007. (O.M.)

  12. Sutura arterial com técnicas contínua e de pontos separados, utilizando-se os fios polipropilene e polidioxanone: estudo experimental em coelhos / Arterial suture with continuous and interrupted techniques, using polypropylene and polydioxanone threads: experimental study in rabbits

    Scientific Electronic Library Online (English)

    Nelson Leonardo Kerdahi Leite de, Campos; Anete Kinumi, Ueda; Marcos Augusto de, Moraes-Silva.

    2003-10-01

    Full Text Available OBJETIVO: Observar o comportamento da sutura arterial em aortas abdominais de coelhos em crescimento, comparando-se as técnicas contínua e com pontos separados, empregando-se dois tipos de fios: Polipropilene 7-0 (inabsorvível) e Polidioxanone 7-0 (absorvível). MÉTODOS: Grupos: GI - Controle (sem su [...] tura); GII - Polipropilene, Pontos Separados; GIII - Polipropilene, Contínua; GIV - Polidioxanone, Pontos Separados e GV - Polidioxanone, Contínua. Cada grupo foi subdividido em quatro Momentos de Eutanásia: aos 7, 14, 30 e 60 dias de pós-operatório. Foram avaliados: peso dos animais, diâmetros e pulsos arteriais, estenose, trombose, aderências, aortografia, visibilidade do fio, cicatrização e microscopia. RESULTADOS: a) após 60 dias, o local da linha de sutura cresceu de forma significativa em todos os grupos; b) a técnica de sutura com pontos separados causou menor estenose da linha de sutura, observada tanto no ato cirúrgico, como na eutanásia dos animais; c) no exame histopatológico, as diferenças encontradas entre grupos foram transitórias, não persistindo após 60 dias de pós-operatório. CONCLUSÃO: O polidioxanone mostrou ser a melhor opção, entre os dois fios, para sutura de artérias em crescimento, pois causa pouca ou nenhuma restrição ao crescimento arterial na linha de sutura, mesmo quando se emprega a técnica contínua. Abstract in english PURPOSE: To assess the arterial suture, comparing continuous and interrupted techniques, in abdominal aorta of growing rabbbits, using two types of suture material: Polypropylene 7-0 (nonabsorbable) and Polydioxanone 7-0 (absorbable). METHODS: Groups: GI - Control, without arterial suture; GII - Pol [...] ypropylene, Interrupted technique; GIII - Polipropilene, Continuous technique; GIV - Polydioxanone, Interrupted technique and GV - Polydioxanone, Continuous technique. Each group was subdivided in four Moments of Euthanasia , according with the number of days after surgery: 7 , 14 , 30 and 60 days. The following itens were assessed: weight, arterial diameters and pulse, stenosis, thrombosis, tissue adherence at the suture line, aortography, suture material visibility, suture line healling visibility and microscopic study. RESULTS: a) after 60 days, the suture line site had a significant growing in all groups; b) interrupted technique result less suture line stenosis in surgical act and in euthanasia c) the difference between groups showed in the microscopic study, was transitory, not pesisting after 60 days post surgery; CONCLUSION: Polydioxanone is better than polypropylene for suture in growing artery, not causing (or causing little) restriction to the growing of the suture line, even though using continuous technique.

  13. Comparison of scar with polypropylene and polyglactin 910 in thyroid incisions

    International Nuclear Information System (INIS)

    To compare quality of scar after subcuticular stitches between Polypropylene (Prolene), a non-absorbable suture, with Polyglactin 910 (Vicryl), an absorbable suture after thyroid surgery. Study Design: Randomized controlled trail (RCT). Place and Duration of Study: Department of Surgery Combined Military Hospital and Military Hospital Rawalpindi from 1 Jan 2007 to 31 Dec 2007. Material and Methods: Sixty patients undergoing elective thyroid surgery were included and randomly divided into two groups using random number tables. Informed written consent was obtained from each patient. The neck wound was closed by subcuticular suturing technique and the suture material was used according to the sampling technique. The patients were followed up in OPD on tenth post operative day and twelve weeks after surgery for the quality of scar. Results: After 10 days, 1 patient in each of the Polypropylene group (3.3%) and Polyglactin 910 group (3.3%) had a bad scar (p = 1.000). After twelve weeks of surgery, 2 patients in the Polypropylene group (6.7%) and 3 patients in the Polyglactin 910 group (10.0%) had bad scars (p = 1.000). Conclusion: There is no significant difference between the frequency of bad scar formation in the Polypropylene and Polyglactin 910 group. It is thus recommended that absorbable Polyglactin 910 sutures should be used for wound closure after thyroid surgery as it does not require suture removal and thus prevents patient anxiety and discomfort and also saves surgeon and staff's time. (author)

  14. Sutura arterial com técnicas contínua e de pontos separados, utilizando-se os fios polipropilene e polidioxanone: estudo experimental em coelhos Arterial suture with continuous and interrupted techniques, using polypropylene and polydioxanone threads: experimental study in rabbits

    Directory of Open Access Journals (Sweden)

    Nelson Leonardo Kerdahi Leite de Campos

    2003-10-01

    Full Text Available OBJETIVO: Observar o comportamento da sutura arterial em aortas abdominais de coelhos em crescimento, comparando-se as técnicas contínua e com pontos separados, empregando-se dois tipos de fios: Polipropilene 7-0 (inabsorvível e Polidioxanone 7-0 (absorvível. MÉTODOS: Grupos: GI - Controle (sem sutura; GII - Polipropilene, Pontos Separados; GIII - Polipropilene, Contínua; GIV - Polidioxanone, Pontos Separados e GV - Polidioxanone, Contínua. Cada grupo foi subdividido em quatro Momentos de Eutanásia: aos 7, 14, 30 e 60 dias de pós-operatório. Foram avaliados: peso dos animais, diâmetros e pulsos arteriais, estenose, trombose, aderências, aortografia, visibilidade do fio, cicatrização e microscopia. RESULTADOS: a após 60 dias, o local da linha de sutura cresceu de forma significativa em todos os grupos; b a técnica de sutura com pontos separados causou menor estenose da linha de sutura, observada tanto no ato cirúrgico, como na eutanásia dos animais; c no exame histopatológico, as diferenças encontradas entre grupos foram transitórias, não persistindo após 60 dias de pós-operatório. CONCLUSÃO: O polidioxanone mostrou ser a melhor opção, entre os dois fios, para sutura de artérias em crescimento, pois causa pouca ou nenhuma restrição ao crescimento arterial na linha de sutura, mesmo quando se emprega a técnica contínua.PURPOSE: To assess the arterial suture, comparing continuous and interrupted techniques, in abdominal aorta of growing rabbbits, using two types of suture material: Polypropylene 7-0 (nonabsorbable and Polydioxanone 7-0 (absorbable. METHODS: Groups: GI - Control, without arterial suture; GII - Polypropylene, Interrupted technique; GIII - Polipropilene, Continuous technique; GIV - Polydioxanone, Interrupted technique and GV - Polydioxanone, Continuous technique. Each group was subdivided in four Moments of Euthanasia , according with the number of days after surgery: 7 , 14 , 30 and 60 days. The following itens were assessed: weight, arterial diameters and pulse, stenosis, thrombosis, tissue adherence at the suture line, aortography, suture material visibility, suture line healling visibility and microscopic study. RESULTS: a after 60 days, the suture line site had a significant growing in all groups; b interrupted technique result less suture line stenosis in surgical act and in euthanasia c the difference between groups showed in the microscopic study, was transitory, not pesisting after 60 days post surgery; CONCLUSION: Polydioxanone is better than polypropylene for suture in growing artery, not causing (or causing little restriction to the growing of the suture line, even though using continuous technique.

  15. Should nylon corneal sutures be routinely removed?

    OpenAIRE

    Jackson, H.(Physics Division, Argonne National Laboratory, Argonne, Illinois, 60439-4843, USA); BOSANQUET, R.

    1991-01-01

    Three groups of patients who had undergone cataract extraction through a corneal incision closed with 10/0 nylon sutures one, two, and three years previously were recalled to determine the incidence of suture related complications. Broken corneal sutures were found in 87.5% of patients after two years and 90% after three years and were causing symptoms in over half the patients. It is recommended that 10/0 nylon corneal sutures be routinely removed no later than one year after surgery.

  16. Deterioration of polypropylene by radiation

    International Nuclear Information System (INIS)

    Radiation sterilization is not applied to the medical implement using polypropylene because of the severe deterioration by gamma ray irradiation. It has been reported that the chain reaction due to oxygen and peroxide radical contributes to the process of deterioration. The authors concluded that by the irradiation of electron beam, the sterilization of the surgical sutures made of polypropylene is feasible, and reported on the correlation of the lowering of the tensile strength by irradiation and the radical formed. However, the ESR spectra of the radical formed in the surgical sutures made of polypropylene irradiated with electron beam and gamma ray were different from the wave form of the peroxide radical of polypropylene reported before, accordingly, the identification was necessary. By this research, the above ESR spectra were proved by the anisotropy of g of peroxide radical, and the second radical other than the above peroxide radical was found. The experimental method and the results are reported. The research on the deterioration of polypropylene by radiation must be forwarded by examining both conventional peroxide radical P and ''S'' radical. (Kako, I.)

  17. Effect of suture material on platelet deposition onto prosthetic material

    International Nuclear Information System (INIS)

    Previous studies have demonstrated the importance of employing prosthetic material with minimal thrombogenicity. However, the role of different suture materials in early thrombotic events on prosthetic materials has not been examined. Experiments were designed to analyze the effects of suture on platelet graft interaction using an in vivo baboon hemocompatability screen. 111Indium labeled, autologous platelet deposition was determined on expanded polytetrafluoroethylene (ePTFE) containing suture lines of polypropylene (Prolene), polybutester (Novafil), and ePTFE (Gore-Tex). A significant increase in platelet deposition was noted not only at the suture line, but proximal and distal to it as well. The results were different for each of the sutures employed and suggest that the suture line may influence early platelet deposition in the perianastomotic region, not only at the suture line, but proximally and distally as well

  18. Electron beam sterilization surgical sutures, 2

    International Nuclear Information System (INIS)

    Possibility of electron beam (1.5 MeV, Van de Graaff accelerator) sterilization of a polypropylene surgical suture was examined from the points of sterilization effect and material degradation by the reason of that ? ray sterilization has not been permitted of its high degree of degradation. The D values of B. pumilus ATCC 27142 dry spores were determined to be 0.11 x 104 Gy in air and 0.18 x 104 Gy under the nitrogen stream irradiation, and the sterilization doses for electron beam were calculated to be 1.6 x 104 Gy in air and 2.7 x 104 Gy under the nitrogen stream, corresponding to ? ray sterilization assurance level of 2.5 x 104 Gy. Tensile strength of the polypropylene suture was 95 % of original strength soon after electron beam irradiation in air and was changed to be 81 % after 6 months storage, this is within the limit of the recommended value of 80 %. Furthermore, heat treatment (85 deg C, 1 hr.) following irradiation reduced degradation of irradiated polypropylene: its tensile strength was 93 % soon after irradiation but 97 % after 6 months. In the case of irradiation under the nitrogen stream, tensile strength after 6 months storage was 73 % without heat treatment, but 93 % with heat treatment. Based on the above results, we concluded that electron beam sterilization is applicable to the polypropylene surgical suture used in this experiment and heat treatment successive irradiation is effective to restrain material degradation. (author)

  19. Sterilization of surgical sutures by electron beam irradiation, (2)

    International Nuclear Information System (INIS)

    For polypropylene threads as surgical sutures as irradiated with electron beam and also with gamma ray for sterilization, the tensile strength, elongation and their variation in course of time, and also the influence of remaining radicals and the effect of heat treatment after irradiation were examined. The index fungus used was the spore of B. pumilus ATCC 27142, and electron beam irradiation was made with a linear accelerator. Gamma ray irradiation was made with cobalt-60. Besides such suture threads as silk, gut, etc., the sterilization of polypropylene sutures, which is impossible by gamma ray, is possible by electron beam irradiation. For polypropylene threads, the heat treatment after irradiation is practically useful. (Mori, K.)

  20. An innovative method to evaluate the suture compliance in sealing the surgical wound lips

    Directory of Open Access Journals (Sweden)

    Farid Saleh, Beniamino Palmieri, Danielle Lodi, Khalid Al-Sebeih

    2008-01-01

    Full Text Available Background and aim: The increasing number of surgical procedures performed with local anesthesia, followed by immediate patient discharge from the hospital, emphasizes the need for a tight waterproof suture that is capable of maintaining its tensile strength in the postoperative phase when the wound tumescence, edema due to the anesthetic drug, and surgical trauma disappear. Moreover, the issue of having an accurate surgical wound closure is very relevant in vivo in order to prevent hemorrhage and exogenous microbial infections. This study aimed at designing a new a lab technique that could be used for evaluating the best surgical material. Using such a technique, we compared the wound-lip-sealing properties of three commonly-used suture threads, namely polyurethane, polypropylene, and polyamide. Materials and methods: The mechanical properties of same-size suture threads made from polyurethane, polypropylene, and polyamide, were compared in order to define the one that possess the best elastic properties by being able to counteract the tension-relaxation process in the first 12 hours following surgery. The tension holding capacity of the suture materials was measured in both in vivo and in vitro experiments. The surface area of the scar associated with the three different suture threads was measured and compared, and the permeability of the three different suture threads was assessed at 0 minute, 2 minute, 4 minute, 6 minute, and 8 minute- interval. Results: Results showed that polyurethane suture threads had significantly (P < 0.05 better tensile strength, elongation endurance before breakage, and better elasticity coefficient as compared to polypropylene and polyamide suture threads. Moreover, polyurethane suture threads were significantly (P < 0.05 more impermeable as compared to the other two suture thread types (polypropylene and polyamide. This impermeability was also associated with a tighter wound-lip-sealing ability, and with significantly (P < 0.05 less scar formation. Conclusion: Among the main concerns that surgeons, physicians, and patients often have is the development infection, oozing, and scar at the incision site following suturing. This always raises the question about which suture to use to avoid the above problems. This study provides evidence that the new technique developed in our lab could be used to compare the wound-lip sealing properties of different surgical suture threads. Using such a technique, the results show that polyurethane is significantly better than other commonly-used suture threads, like polypropylene and polyamide, in relation to wound sealing and scar formation.

  1. Radiochemical sterilization and its use for sutures

    International Nuclear Information System (INIS)

    Radiochemical sterilization (RC-S) represents a novel approach to medical device sterilization. It is a hybrid process encompassing the attributes of chemical and high-energy radiation sterilization without the drawbacks associated with the use of the parent processes. It entails the use of a 5-7.5 kGy of ? radiation and a polyformaldehyde insert capable of a radiolytic-controlled release of formaldehyde gas in a hermetically sealed package under dry nitrogen. The RC-S process has been applied successfully to radiation-sensitive sutures, namely polypropylene monofilaments and absorbable polyglycolide braids

  2. A new surgical technique using steel suture for trans-scleral fixation of posterior chamber intraocular lenses

    Directory of Open Access Journals (Sweden)

    Jagat Ram

    2013-01-01

    Full Text Available Background: A new emerging complication of trans-scleral fixation of posterior chamber (PC intraocular lens (IOL with polypropylene suture is high rates of spontaneous dislocation of the IOL due to disintegration or breakage of suture. Materials: We report a new surgical technique of trans-scleral fixation of posterior chamber intraocular lens (SF PCIOL with steel suture to eliminate the complication of dislocation of IOL fixed with polypropylene suture in one adult and a child. Results: We successfully achieved stable fixation and good centration of IOL after SF PCIOL with steel suture in these patient having inadequate posterior capsular support. Both eyes achieved best corrected visual acuity 20/40 at 18 months follow-up. Conclusions: Steel suture is a viable option for trans-scleral fixation of posterior chamber intraocular lens.

  3. 15 CFR 10.0 - General.

    Science.gov (United States)

    2010-01-01

    ... PRODUCT STANDARDS § 10.0 General. (a) Introduction. The Department of Commerce (hereinafter referred to as... current with respect to advancing technology and marketing practices. (e) Role of the National...

  4. [Vascular microsutures with resorbable and nonresorbable sutures. A comparative study].

    Science.gov (United States)

    Vasquez, G; Mascoli, F; Rubbini, M; Pollinzi, V; Ortolani, M; Occhionorelli, S; Donini, A; Navarra, G; Bresadola, V; Romano, D

    1991-05-01

    Modern technology has recently provided us with new resorbable suture material for use also in vascular surgery. Clinical use of these sutures has been impeded however by not little mistrust and by old dogmas without a rational experimental basis. We have therefore begun studies of two slowly resorbable materials, polyglactin 910 and polyglycolic acid, in comparison with two classic nonreabsorbable materials, nylon and polypropylene, used in experimental model of end-to-end anastomosis rats'infrarenal aorta, following up the healing process and its evolution after an interval. The results are discussed in relation to data collected from current literature. PMID:1659675

  5. A comparison of ultrasonic suture welding and traditional knot tying.

    Science.gov (United States)

    Richmond, J C

    2001-01-01

    The slippage of knots and the technical challenge of tying them securely are potential impediments to certain arthroscopic procedures. Ultrasonic energy delivered at 70 kHz can be used to weld No. 2 polypropylene suture. This method was compared with a traditional knot (surgeon's knot with four alternating half hitches) tied with an open technique to determine whether welding of sutures is comparable, in mechanical properties, to hand-tied knots. Both loops were fashioned around a 0.25-inch mandrel and then tested. The load to reach 3-mm elongation (point of likely biologic failure of a repair) was significantly greater for welded sutures than for knots. The elongation at ultimate failure was significantly less for welded sutures than for knots. The number of cycles to failure and the creep after initial displacement were similar for both welded and knotted suture loops. The ultimate load to failure was significantly greater for the knotted than for the welded suture. The welding of suture for the repair of musculoskeletal soft tissue presents an attractive alternative to traditional knot tying, particularly for arthroscopic applications. PMID:11394598

  6. [Suture materials in dermatology].

    Science.gov (United States)

    Hundeiker, M

    1988-01-01

    In a short review, we describe the chemical, physical, and mechanical properties of some skin suture materials. More attention must be paid to the elasticity of most modern synthetic materials as a cause for ingrowing loops in sutures with too much tension. In addition, we deal with the various dissolution times of absorbable materials. PMID:3073602

  7. GENIE Production Release 2.10.0

    CERN Document Server

    Alam, M; Athar, M; Bodek, A; Christy, E; Coopersmith, B; Dennis, S; Dytman, S; Gallagher, H; Geary, N; Golan, T; Hatcher, R; Hoshina, K; Liu, J; Mahn, K; Marshall, C; Morrison, J; Nirkko, M; Nowak, J; Perdue, G N; Yarba, J

    2015-01-01

    GENIE is a neutrino Monte Carlo event generator that simulates the primary interaction of a neutrino with a nuclear target, along with the subsequent propagation of the reaction products through the nuclear medium. It additionally contains libraries for fully-featured detector geometries and for managing various types of neutrino flux. This note details recent updates to GENIE, in particular changes introduced into the newest production release, version 2.10.0.

  8. USE OF POLYPROPYLENE MESH FOR INCISIONAL HERNIA REPAIR

    OpenAIRE

    Scripcariu V; Timofte D; Timofeiov S; Lefter L; Radu I; Dragomir C.

    2006-01-01

    Incisional hernia is an important complication of abdominal surgery. Procedures for the repair of these hernias with sutures and with mesh have been reported, but there is no consensus about which type of procedure is the best. We have performed a retrospective analysis on 1128 patients operated on in our unit between 1994 and 2004 for simple or recurrent incisional hernias. The polypropylene mesh has been used in a number of 138 patients. The mesh has been placed either intraperitone...

  9. Laser division of intraluminal sutures.

    Science.gov (United States)

    Bagley, D H; Schultz, E; Conlin, M J

    1998-08-01

    Neodymium:YAG and holmium:YAG lasers were used to remove intraluminal sutures from three patients. In two, the suture was in the bladder and had served as a nidus for stone formation. In the other, the suture was in the ureter. An in vitro study showed that the Nd:YAG laser could divide all types of suture readily, whereas the Ho:YAG laser could divide all materials except Gortex. These cases illustrate another application for lasers. PMID:9726402

  10. Selective suture cutting for control of astigmatism following cataract surgery

    Directory of Open Access Journals (Sweden)

    Bansal R

    1992-01-01

    Full Text Available Use of 10-0 monofilament nylon in ECCE cataract surgery leads to high with the rule astigmatism. Many intraoperative and post operative methods have been used to minimise post operative astigmatism. We did selective suture cutting in 38 consecutive patients. Mean keratometric astigmatism at three and six weeks post operative was 5.76 and 5.42 dioptres (D respectively. 77.5% of eyes had astigmatism above 2 D. Selective suture cutting along the axis of the plus high cylinder was done after six weeks of surgery. Mean post suture cutting keratometric astigmatism was 3.3 D and 70% of the eyes had astigmatism below 2 D. After 3 months of surgery mean keratometric astigmatism was reduced to 1.84 D. Axis of the astigmatism also changed following suture cutting. 40% of the eyes showed improvement in their Snellen acuity following reduction in the cylindrical power.

  11. Strength enhancement of the interlocking mechanism in cross-stitch peripheral sutures for flexor tendon repair: biomechanical comparisons by cyclic loading.

    Science.gov (United States)

    Takeuchi, N; Mitsuyasu, H; Hotokezaka, S; Miura, H; Higaki, H; Iwamoto, Y

    2010-01-01

    The fatigue strength of three peripheral suture techniques for flexor tendon repair was compared by cyclic loading of repairs in a cotton dental roll tendon model. Thirty pairs of dental roll were sutured using only peripheral sutures with 6-0 polypropylene. An initial cyclic load of 5 N for 500 cycles was applied and increased by 5 N for an additional 500 cycles at each new load until rupture. The fatigue strength of an interlocking cross-stitch suture was 113% greater than a running suture and 36% greater than a standard cross-stitch suture. Interlocking the cross-stitch prevented shortening of the transverse portions under load and appears to be a useful technique for increasing the strength of the peripheral suture. PMID:19786410

  12. Suturas mecânicas Mechanic sutures

    Directory of Open Access Journals (Sweden)

    Alexandre Miranda Duarte

    2002-10-01

    Full Text Available The authors review the use of staplers in General Surgery, mainly in Gastroenterological Surgery highlighting safety and effectiveness. They emphasize that the mechanic anastomosis are a viable technique and in some conditions, the best way to perform the anastomosis. The use of staplers makes surgery faster and easier and complications are, generally related to surgeon's experience in using them. Although its costs are higher compared to handsewn suture, it can make the patient total cost lower.

  13. Comparison of Subcuticular Suture Materials in Cesarean Skin Closure.

    Science.gov (United States)

    Hasdemir, P?nar Solmaz; Guvenal, Tevfik; Ozcakir, Hasan Tayfun; Koyuncu, Faik Mumtaz; Dinc Horasan, Gonul; Erkan, Mustafa; Oruc Koltan, Semra

    2015-01-01

    Aim. Comparison of the rate of wound complications, pain, and patient satisfaction based on used subcuticular suture material. Methods. A total of 250 consecutive women undergoing primary and repeat cesarean section with low transverse incision were prospectively included. The primary outcome was wound complication rate including infection, dehiscence, hematoma, and hypertrophic scar formation within a 6-week period after operation. Secondary outcomes were skin closure time, the need for use of additional analgesic agent, pain score on numeric rating scale, cosmetic score, and patient scar satisfaction scale. Results. Absorbable polyglactin was used in 108 patients and nonabsorbable polypropylene was used in 142 patients. Wound complication rates were similar in primary and repeat cesarean groups based on the type of suture material. Skin closure time is longer in nonabsorbable suture material group in both primary and repeat cesarean groups. There was no difference between groups in terms of postoperative pain, need for additional analgesic use, late phase pain, and itching at the scar. Although the cosmetic results tended to be better in the nonabsorbable group in primary surgery patients, there was no significant difference in the visual satisfaction of the patients. Conclusions. Absorbable and nonabsorbable suture materials are comparable in cesarean section operation skin closure. PMID:26413566

  14. Biodegradation of Polypropylene Nonwovens

    Science.gov (United States)

    Keene, Brandi Nechelle

    The primary aim of the current research is to document the biodegradation of polypropylene nonwovens and filament under composting environments. To accelerate the biodegradat ion, pre-treatments and additives were incorporated into polypropylene filaments and nonwovens. The initial phase (Chapter 2) of the project studied the biodegradation of untreated polypropylene with/without pro-oxidants in two types of composting systems. Normal composting, which involved incubation of samples in food waste, had little effect on the mechanical properties of additive-free spunbond nonwovens in to comparison prooxidant containing spunbond nonwovens which were affected significantly. Modified composting which includes the burial of samples with food and compressed air, the polypropylene spunbond nonwovens with/without pro-oxidants displayed an extreme loss in mechanical properties and cracking on the surface cracking. Because the untreated spunbond nonwovens did not completely decompose, the next phase of the project examined the pre-treatment of gamma-irradiation or thermal aging prior to composting. After exposure to gamma-irradiation and thermal aging, polypropylene is subjected to oxidative degradation in the presence of air and during storage after irradiat ion. Similar to photo-oxidation, the mechanism of gamma radiation and thermal oxidative degradation is fundamentally free radical in nature. In Chapter 3, the compostability of thermal aged spunbond polypropylene nonwovens with/without pro-oxidant additives. The FTIR spectrum confirmed oxidat ion of the polypropylene nonwovens with/without additives. Cracking on both the pro-oxidant and control spunbond nonwovens was showed by SEM imaging. Spunbond polypropylene nonwovens with/without pro-oxidants were also preirradiated by gamma rays followed by composting. Nonwovens with/without pro-oxidants were severely degraded by gamma-irradiation after up to 20 kGy exposure as explained in Chapter 4. Furthermore (Chapter 5), gamma-irradiated polypropylene nonwovens with pro-oxidants were invisible to the naked eye after 30 days of composting suggesting microbial attack was achieved. The final phase of the project encompasses the extrusion of bicomponent fibers. Because microorganisms desire to feed on hydrophilic molecules, commercially available starch-based polymers were spun with polypropylene resins in a sheath/core configuration. Similar to the previously discussed nonwovens studies, the bicomponent filaments were pretreated with heat (Chapter 6) and gamma-rays (Chapter 7) before evaluating the biodegradability under composting studies. The results from these chapters were reviewed to determine if bicomponent nonwovens under the same conditions could be manufactured.

  15. The biomechanical assessment of gap formation after flexor tendon repair using partial interlocking cross-stitch peripheral sutures.

    Science.gov (United States)

    Takeuchi, N; Mitsuyasu, H; Kikuchi, K; Shimoto, T; Higaki, H; Iwamoto, Y

    2011-09-01

    The gap formation of five core plus peripheral suture techniques for flexor tendon repair was evaluated by cyclic load testing. Fifty pairs of dental roll tendon models were sutured using six-strand Pennington modified Kessler core suture with 4-0 Polypropylene. One-half or three-fourths circumferential interlocking cross-stitch, or three complete circumferential peripheral suture techniques were performed using 6-0 Polypropylene. An initial cyclic load of 10 N for 500 cycles was applied and increased by 5 N for an additional 500 cycles at each new load until rupture. The complete circumferential interlocking cross-stitch had the greatest fatigue strength. The partial circumferential cross-stitches resulted in significantly larger gap formations at both the repaired and unrepaired sides than the complete circumferential sutures, and were also associated with early rupture. The full circumference of the cut tendon must be sutured using an interlocking cross-stitch peripheral suture to improve strength and avoid gap formation. PMID:21546417

  16. Influence of suture regularity on corneal astigmatism after penetrating keratoplasty

    DEFF Research Database (Denmark)

    Hjortdal, Jesper; SØndergaard, Anders

    2011-01-01

    Abstract. Purpose: To investigate whether suture regularity affects corneal astigmatism after keratoplasty. Methods: Twenty-one patients undergoing penetrating keratoplasty for various corneal diseases were included in the study. The grafts were sutured in place using a single-running Nylon 10-0 suture, taking 24 bites. Immediately after surgery, standard calibrated images of the grafted eye were captured and stored. Using a dedicated image analysis programme, stitches and needle points were identified, and a number of suture regularity variables were calculated. Corneal topographic images were obtained before suture removal (12 months after surgery) and 3 months after suture removal (18 months after surgery). Topographic measures of astigmatism [surface regularity (SRI), surface asymmetry index (SAI) and simulated keratometric astigmatism] were calculated and correlated with the computed suture regularity variables. Results: The average stitch length was 3.04 +/- 0.28 mm and the distance between the outer needle points was 2.53 +/- 0.09 mm. The SRI was 1.26 +/- 0.36 and the SAI was 1.59 +/- 0.67 after 12 months; these decreased to 1.03 +/- 0.48 and 0.92 +/- 0.46 after 18 months, respectively. Corneal astigmatism was 6.38 +/- 2.99 and 5.87 +/- 3.13 dioptres after 12 and 18 months, respectively. Suture regularity did not affect SAI, SRI or corneal astigmatism significantly 12 months after surgery. Eighteen months after surgery (3 months after suture removal), the standard deviation on the original stitch length was found to significantly increase corneal astigmatism. In addition, the size of the counter-clockwise angle between stitch and graft radian was correlated significantly with a lower SRI. Conclusion: The origin of corneal astigmatism after penetrating keratoplasty is multifaceted. Regular stitch length and stitch advancement on the surface appears to improve the optical quality of the graft after suture removal. Factors such as stitch depth, suture tension and variations in wound construction might also beimportant predictors of corneal astigmatism after penetrating keratoplasty.

  17. Releasable suture technique for trabeculectomy

    Directory of Open Access Journals (Sweden)

    Thomas Ravi

    1997-01-01

    Full Text Available A retrospective review of 154 trabeculectomies with releasable sutures was performed to assess the effect of suture release on intraocular pressure (IOP at various postoperative periods. Release of the suture was necessary in 38% of cases. The immediate reduction in IOP was significant (p <0.01 when the suture was released during the first three postoperative weeks. Seventy percent of eyes had a reduction in IOP more than 5 mmHg if released within the first week compared to 20% after the third week. With suture release after the third postoperative week, there was no clinically significant decrease in IOP. The decrease in IOP was similar in eyes undergoing trabeculectomy alone or when cataract extraction through a separate corneal incision was undertaken simultaneously. The period during which release of suture was effective was not prolonged by use of antimetabolites. Complications included a typical windshield-wiper keratopathy (18 eyes, failure to release the suture (13 eyes, epithelial abrasion (6 eyes and a sub-conjunctival bleed (1 eye.

  18. 31 CFR 10.0 - Scope of part.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Scope of part. 10.0 Section 10.0 Money and Finance: Treasury Office of the Secretary of the Treasury PRACTICE BEFORE THE INTERNAL REVENUE... public accountants, enrolled agents, and other persons representing clients before the Internal...

  19. Advances in polypropylene based materials

    International Nuclear Information System (INIS)

    Polypropylene is an extremely versatile thermoplastic polymer known for its good performance/price ratio, excellent heat, moisture and chemical resistance, favorable processing characteristics and recyclability. Due to its universal properties, polypropylene is applied in numerous industrial fields such as electronic and electrical, automobile, textile, pipeline, etc. Furthermore, the progress in its synthesis and property modification in the last decade has contributed to the development of new polypropylene based materials with advanced performance. This review aims at reporting on some recent developments in polypropylene based materials, such as nano fibers, natural fiber reinforced composites, self-reinforced polypropylene and polypropylene/clay hybrids, that have replaced many types of engineering thermoplastics in high-performance applications. (Author)

  20. CORNEAL ASTIGMATISM AFTER ECCE: A COMPARATIVE STUDY BETWEEN SILK VERSUS NYLON SUTURE

    Directory of Open Access Journals (Sweden)

    Sunita

    2013-11-01

    Full Text Available ABSTRAC T: INTRODUCTION: Cataract as a potent cause of loss of vision in old age persons is probably known since the dawn of human civilization. Post operative astigmatism after cataract extraction remains a big problem for cataract surgeons since Jacques Daviel e ra. Astigmatism is that type of refractive anomaly in which no point focus is formed owing to the unequal refraction of the incident light by the diopteric system of the eye in different meridians. The goal of modern cataract surgery is to produce a pseudo phakic with the quality of vision of a normal phakic eye. Various studies to find out any effect of IOL on post operative astigmatism were carried out but results are controversial. MATERIAL AND METHODS: 60 patients suffering from cataract and fit for extr action were enlisted during the month of August 2008 to February 2009. The general, physical and local examination including preoperative Keratometry, vision and tension were recorded. RESULTS: In the present study, male patients were 38 (63% and female p atients were 22 (37%. Out of the total 60 cases studied, corneo - scleral section of 28 cases (47% were sutured with 10 - 0 nylon suture (Group A while sections of 32 cases were sutured with 8 - 0 black virgin silk suture (Group B.Out of 28 cases of Group A, interrupted sutures were applied in 14 cases (50% (Group A 1 . Cross interrupted sutures were applied in 9 cases (32% Group A 2 , while bootlace continuous sutures were applied in 5 cases (18% (Group A 3 . Out of 32 cases of Group B, interrupted sutures we re applied in 26 cases (80% (Group B 1 , cross interrupted were applied in 3 cases (10% (Group B 2 , while bootlace continuous suture were applied in 3 cases (Group B 3 . In the present series, 19 cases (31% showed with the rule astigmatism, 21 cases (36% showed astigmatism against the rule and 20 cases (33% showed no astigmatism preoperatively, 16 cases were in the range of 0.50D to 1.0D and 12 cases were in the range of 1.0D to 1.50D. CONCLUSION: To conclude the findings, 10 - 0 nylon cross interrupted su tures and 8 - 0 silk cross interrupted sutures are relatively better and causes less degree of postoperative astigmatism in comparison to other suture technique. Decreased postoperative astigmatism can be achieved by posterior limbal incision, small section, limited use of sclera cauterization, proper depth of suture bite and limited use of topical steroids. Type of suture material and suture technique plays a minor role on postoperative astigmatism

  1. U10.0 Undulator conceptual design report

    Energy Technology Data Exchange (ETDEWEB)

    Hoyer, E.

    1994-06-01

    The U10.0 Undulator described here is a 43 period, 10 cm period, 4.5 meter long insertion device. Designed for the Advanced Light Source (ALS) storage ring at the Lawrence Berkeley Laboratory. This insertion device will provide high brightness, quasi-monochromatic radiation in the 5-950 eV energy range. This conceptual design report includes sections on: parameter development, spectral performance, and accelerator requirements, physics specifications and the detailed conceptual design of the magnetic structure, the support/drive systems, the insertion device control system, the vacuum system, and installation for the U10.0 Undulator.

  2. U10.0 Undulator conceptual design report

    International Nuclear Information System (INIS)

    The U10.0 Undulator described here is a 43 period, 10 cm period, 4.5 meter long insertion device. Designed for the Advanced Light Source (ALS) storage ring at the Lawrence Berkeley Laboratory. This insertion device will provide high brightness, quasi-monochromatic radiation in the 5-950 eV energy range. This conceptual design report includes sections on: parameter development, spectral performance, and accelerator requirements, physics specifications and the detailed conceptual design of the magnetic structure, the support/drive systems, the insertion device control system, the vacuum system, and installation for the U10.0 Undulator

  3. Torsion of monofilament and polyfilament sutures under tension decreases suture strength and increases risk of suture fracture.

    LENUS (Irish Health Repository)

    Hennessey, D B

    2012-08-01

    A continuous running suture is the preferential method for abdominal closure. In this technique the suture is secured with an initial knot and successive tissue bites are taken. At each tissue bite, the needle is rotated through the tissue; in doing so, the suture can twist around the knot which acts as an anchor.

  4. The radiation degradation of polypropylene

    International Nuclear Information System (INIS)

    Polypropylene is used extensively in the manufacture of disposable medical devices because of its superior properties. Unfortunately this polymer does not lend itself well to radiation sterilization, undergoing serious degradation which affects the mechanical properties of the polymer. In this paper the effects of radiation on the mechanical and physical properties of polypropylene are discussed. A programme of research to minimize the radiation degradation of this polymer through the addition of crosslinking agents to counteract the radiation degradation is proposed. It is furthermore proposed that a process of annealing of the irradiated polymer be investigated in order to minimize the post-irradiation degradation of the polypropylene

  5. Unusual sutural bones at pterion

    Directory of Open Access Journals (Sweden)

    Nayak SB

    2008-08-01

    Full Text Available The existence of Wormian (sutural bones in the skull is well known. We found three unusual Wormian bones at the right pterion in an adult Indian skull. The variation noted was unilateral. This type of variation has not been reported yet.

  6. Composite surgical sutures with bioactive glass coating.

    Science.gov (United States)

    Boccaccini, Aldo R; Stamboulis, Artemis G; Rashid, Azrina; Roether, Judith A

    2003-10-15

    A processing method was developed to coat polyglactin 910 (Vicryl) sutures with bioactive glass powder (45S5 Bioglass). High reproducibility and homogeneity of the coating in terms of microstructure and thickness along the suture length were achieved. Bioglass-coated sutures exhibited a high level of chemical reactivity in simulated body fluid (SBF), indicating their bioactive behavior. This was evident by the prompt formation of hydroxyapatite (HA) crystals on the surface after only 7 days of immersion in SBF. These crystals grew to form a thick HA layer (15 microm thickness) after 3 weeks in SBF. The tensile strength of the sutures was tested before and after immersion in SBF in order to assess the effect of the bioactive glass coating on suture degradation. The tensile strength of composite sutures was lower than that of as-received Vicryl sutures, 385 and 467 MPa, respectively. However, after 28 days of immersion in SBF the residual tensile strengths of coated and uncoated sutures were similar (83 and 88 MPa, respectively), indicating no negative effect of the HA layer formation on the suture strength. The effect of bioactive glass coating on the polymer degradation is discussed. The developed bioactive sutures represent interesting materials for applications in wound healing, fabrication of fibrous three-dimensional scaffolds for tissue engineering, and reinforcement elements for calcium-phosphate temporary implants. PMID:14528459

  7. The optimal blend ratio of recycling polypropylene waste with pure polypropylene

    International Nuclear Information System (INIS)

    Blends of thermomechanical degraded polypropylene and virgin polypropylene materials have been prepared with different compostttion by weight. To produce the same end-use items, mechanical properties showed that the optimal blend ratio by weight is 25% of Rafia polypropylene waste to 75% of virgin polypropylene. Blends containing ratios by weight of 40% Rafia polypropylene waste (R-PP). to 60% of either virgin polypropylene (V-PP), or photo-oxidized degraded polypropylene (W--PP) are both suitable to produce agricultural crates of acceptable performance. The experimental results are explained in terms of structural and morphological changes. (author). 19 refs., 8 figs.,3 tabs

  8. USE OF POLYPROPYLENE MESH FOR INCISIONAL HERNIA REPAIR

    Directory of Open Access Journals (Sweden)

    Scripcariu V

    2006-07-01

    Full Text Available Incisional hernia is an important complication of abdominal surgery. Procedures for the repair of these hernias with sutures and with mesh have been reported, but there is no consensus about which type of procedure is the best. We have performed a retrospective analysis on 1128 patients operated on in our unit between 1994 and 2004 for simple or recurrent incisional hernias. The polypropylene mesh has been used in a number of 138 patients. The mesh has been placed either intraperitoneal, extraperitoneal/ subfascial or onlay. Median follow-up was 36 months. There were 1 enterocutaneous fistula and 5 wound sinus developed. The mesh had to be removed in 6 cases. All of these complication developed when the mesh has been placed either extraperitoneally/subfascial or onlay. We note 5 recurrent incisional hernias after a period of up to 24 months. The recurrence rates after open mesh repair are less then after primary closure. The intraperitoneal use of polypropylene mesh with omental coverage is a good procedure with less complications.

  9. Suturing techniques and postoperative management in penetrating keratoplasty in the United Kingdom

    Directory of Open Access Journals (Sweden)

    Lee RM

    2012-08-01

    Full Text Available Richard MH Lee,1 Fook Chang Lam,1 Tassos Georgiou,1 Bobby Paul,1 Kong Yong Then,1 Ioannis Mavrikakis,1 Venkata S Avadhanam,1 Christopher SC Liu1,21Sussex Eye Hospital, Brighton, United Kingdom; 2Tongdean Eye Clinic, Hove, United KingdomAims: To report on the suturing techniques and aspects of postoperative management in penetrating keratoplasty in the United Kingdom.Methods: A postal questionnaire was sent to 137 ophthalmic consultants identified from a Royal College of Ophthalmology database as having a special interest in anterior segment surgery. The questionnaire surveyed surgeon preferences for surgical and suturing technique for penetrating keratoplasty surgery, and the postoperative care of corneal grafts.Results: In all, 68% of questionnaires were completed and returned: 73% of respondents used a Flieringa ring or equivalent, 94% routinely used cardinal sutures, with 50.5% removing them at the end of the procedure. The most common suturing technique for routine penetrating keratoplasty was a single continuous suture (35%. In these cases, a 10/0 nylon suture was used by 89%. Sixty-six percent changed their technique in high-risk cases, 52% used a 3-1-1 knot, and 75% made a distinction between a reef and granny knot, with 76% using a reef. Thirty percent buried the knots within the donor material, and 29% within the host tissue. Twenty-five percent had no routine time for graft suture removal, but 41% removed them between 1 and 2 years post-surgery. After suture removal, 98% used steroids and 88% used topical antibiotics. Thirty-four percent stopped topical steroids before suture removal, with 38% stopping topical steroids more than 3 months prior to suture removal.Conclusion: This survey demonstrates that there is considerable variation in suturing techniques and postoperative care for penetrating keratoplasty. These significant variations in practice need to be considered when interpreting outcomes and research.Keywords: corneal graft, penetrating keratoplasty, anterior segment surgery, cornea, corneal surgery, corneal transplantation

  10. Method for making thin polypropylene film

    Science.gov (United States)

    Behymer, R.D.; Scholten, J.A.

    1985-11-21

    An economical method is provided for making uniform thickness polypropylene film as thin as 100 Angstroms. A solution of polypropylene dissolved in xylene is formed by mixing granular polypropylene and xylene together in a flask at an elevated temperature. A substrate, such as a glass plate or microscope slide is immersed in the solution. When the glass plate is withdrawn from the solution at a uniform rate, a thin polypropylene film forms on a flat surface area of the glass plate as the result of xylene evaporation. The actual thickness of the polypropylene film is functional of the polypropylene in xylene solution concentration, and the particular withdrawal rate of the glass plate from the solution. After formation, the thin polypropylene film is floated from the glass plate onto the surface of water, from which it is picked up with a wire hoop.

  11. 21 CFR 878.4830 - Absorbable surgical gut suture.

    Science.gov (United States)

    2010-04-01

    ... false Absorbable surgical gut suture. 878.4830 Section...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...4830 Absorbable surgical gut suture. (a) Identification. An absorbable surgical gut suture, both plain...

  12. Argon plasma irradiation of polypropylene.

    Czech Academy of Sciences Publication Activity Database

    Vasina, A.; Malinský, Petr; Slepi?ka, P.; Macková, Anna; Švor?ík, V.

    Cambridge : IOP, Institute of physics, 2009. s. 83-83. [19th International conference on Ion beam analysis. 07.09.2009-11.09.2009, Cambridge] R&D Projects: GA MŠk(CZ) LC06041 Institutional research plan: CEZ:AV0Z10480505 Keywords : polypropylene * plasma treatment * RBS * XPS * zeta potential Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders

  13. Torrefied biomass-polypropylene composites

    Science.gov (United States)

    Torrefied almond shells and wood chips were incorporated into polypropylene as fillers to produce torrefied biomass-polymer composites. Response surface methodology was used to examine the effects of filler concentration, filler size, and lignin factor (relative lignin to cellulose concentration) on...

  14. Woodflour as Reinforcement of Polypropylene

    Directory of Open Access Journals (Sweden)

    José Cláudio Caraschi

    2002-10-01

    Full Text Available The effect of the filler content and size, as well as accelerated aging on the mechanical properties of polypropylene composites reinforced with woodflour (WF/PP were evaluated. The composites were prepared by the extrusion of polypropylene with woodflour (Pinus elliotti based on following ratios: 15, 25 and 40 wt% with two different granulometries. The specimens were injection molded according to ASTM standards. The composite properties did not show significant differences as a function of the filler granulometry. We also observed that by increasing the filler content, both the mechanical properties and the melt flow index (MFI decreased, and the elasticity modulus, hardness and density increased. Concerning the accelerated aging, the composite presented a reduction in tensile properties. The results showed that the composite properties are extremely favorable when compared to other commercial systems reinforced by inorganic fillers.

  15. Fracture Toughness Studies of Polypropylene- Clay Nanocomposites and Glass Fibre Reinfoerced Polypropylene Composites

    OpenAIRE

    A. Ramsaroop; K. Kanny; T.P. Mohan

    2010-01-01

    In this paper, a comparative study on the fracture toughness of woven glass fibre reinforced polypropylene, chopped glass fibre reinforced polypropylene and nanoclay filled polypropylene composites is presented. Nanoclays (Cloisite 15A) of 1 wt. % to 5 wt. % were filled in polypropylene (PP) matrix and they were subjected to fracture toughness stu-dies. The specimen with 5 wt. % nanoclay showed 1.75 times and 3 times improvement in critical stress intensity factor (KIC) and strain energy rele...

  16. Influence of different length of core suture purchase among suture row on the strength of 6-strand tendon repairs.

    Science.gov (United States)

    Okubo, Hirotaka; Kusano, Nozomu; Kinjo, Masaki; Kanaya, Fuminori

    2015-01-01

    In multi-strand suture methods consisting of several suture rows, the different length of core suture purchase between each suture row may affect the strength of repairs. We evaluated the influence of the different length of core suture purchase between each suture row on the strength of 6-strand tendon repairs. Rabbit flexor tendons were repaired by using a triple-looped suture technique in which the suture purchase length in each suture row was modified. Group 1, all lengths are 8-mm. Group 2, all lengths are 10-mm. Group 3, two are 10-mm and one is 8-mm. Group 4, one is 10-mm and two are 8-mm. The repaired tendons were subjected to load-to-failure test. The gap strength was significantly greater in Group 1 and Group 2 than in Group 3 and Group 4. This study demonstrates that maintaining equal core suture purchase lengths of each suture row increases the gap resistance. PMID:25609270

  17. Oxidation induced embrittlement in polypropylene

    OpenAIRE

    Fayolle, Bruno

    2001-01-01

    The thermooxidative ageing of polypropylene (PP) films, in the 70-140°C temperature range, has been studied by common (FTIR spectrophotometry, tensile testing) and less common (molecular mass measurements, Essential Work of Fracture) methods. It appears that the polymer, initially very ductile, adopts a brittle behaviour in tensile test, whereas oxidation remains undetectable by FTIR measurements. This embrittlement, corresponding to a localization of the plastic deformation, appears to be li...

  18. Changes in mechanical properties of recycled polypropylene.

    OpenAIRE

    Weckström, Dan

    2012-01-01

    The objective of the thesis was to find out how recycling affects the mechanical properties of polypropylene. The mechanical properties were tensile strength, Young`s modulus and melt flow index. The mechanical properties for the raw material of polypropylene were compared with the recycled ones. The same material was recycled 14th times in order to get a view of how the recycling affects the mechanical properties of polypropylene. The mechanical properties were tested with a testometric tens...

  19. Mechanics of cranial sutures using the finite element method.

    Science.gov (United States)

    Jasinoski, S C; Reddy, B D; Louw, K K; Chinsamy, A

    2010-12-01

    To investigate how cranial suture morphology and the arrangement of sutural collagen fibres respond to compressive and tensile loads, an idealised bone-suture-bone complex was analysed using a two-dimensional finite element model. Three suture morphologies were simulated with an increasing interdigitation index (I.I.): butt-ended, moderate interdigitated, and complex interdigitated. The collagen matrix within all sutures was modelled as an isotropic material, and as an orthotropic material in the interdigitated sutures with fibre alignment as reported in studies of miniature pigs. Static uniform compressive or tensile loading was applied to the complex. In interdigitated sutures with isotropic material properties, the orientation of the maximum (tensile) principal stresses within the suture matched the collagen fibre orientation observed in compressed and tensed sutures of miniature pigs. This suggests that randomly arranged sutural collagen fibres could optimise to an orientation most appropriate to withstand the predominant type of loading. A compression-resistant fibre arrangement imparted the highest suture strain energy relative to the isotropic and tension-resistant arrangements, indicating that this configuration maximises energy storage. A comparison across the different suture morphologies indicated that bone strain energy generally decreased with a decrease in I.I., irrespective of the sutural fibre arrangement. However, high bone stress at the interdigitation apices shifted to the limbs of the suture with an increase in I.I. These combined findings highlight the importance of suture morphology and anisotropy as properties having a significant influence on sutural mechanics. PMID:20825945

  20. Suturing technique for extraocular muscle surgery.

    Science.gov (United States)

    Kraushar, M F; Mercur, L

    1977-10-01

    A method for suturing extraocular muscles is presented which provides a safe, anatomically perfect means of reattaching extraocular muscles after recession, resection, or after disinsertion at retinal surgery. PMID:335948

  1. Suture refixation and recentration of a subluxated capsular tension ring-capsular bag-intraocular lens complex.

    Science.gov (United States)

    Gimbel, Howard V; Amritanand, Anika

    2013-12-01

    We describe a 3-point ab externo technique to refixate and recenter a subluxated Cionni capsular tension ring (CTR)-intraocular lens (IOL)-capsular bag complex to the sclera. A 9-0 polypropylene suture on a curved needle is looped through the eyelet of the CTR and back through a Hoffman scleral tunnel. Two other sutures passed in a similar fashion through the fibrotic continuous curvilinear capsulorhexis (CCC) edge are used to complete a tripod fixation, which centers and stabilizes the IOL. This surgical approach avoids the surgical trauma of removing and replacing a subluxated CTR-IOL-capsular bag complex, retains the optimal anatomical position, and ensures centration of the IOL. PMID:24286838

  2. A contact invariant in sutured monopole homology

    OpenAIRE

    Baldwin, John A.; Sivek, Steven

    2014-01-01

    We define an invariant of contact 3-manifolds with convex boundary using Kronheimer and Mrowka's sutured monopole Floer homology theory (SHM). Our invariant can be viewed as a generalization of Kronheimer and Mrowka's contact invariant for closed contact 3-manifolds and as the monopole Floer analogue of Honda, Kazez, and Mati\\'c's contact invariant in sutured Heegaard Floer homology (SFH). In the process of defining our invariant, we construct maps on SHM associated to contact handle attachme...

  3. Needle and suture contamination in strabismus surgery

    OpenAIRE

    Betül Tu?cu; Seyhan Ördekçi; F?rat Helvac?o?lu; Nazire Terzi; Sad?k ?encan

    2007-01-01

    Objective: To evaluate the level of bacterial contamination of needles and sutures used in strabismus surgery. Material and Methods: Strabismus surgery was performed on 30 eyes of 20 patients in our clinic between January 2004 and June 2004. Preoperative site preparation included installation of 5% povidine-iodine in the conjunctival fornices in all cases. A total of 60 needles and 60 sutures were cultured immediately after final scleral passage. Results: Ten of the 20 cases (50%) produced at...

  4. Prolene monofilament suture in Boston Keratoprosthesis surgery

    OpenAIRE

    Kyrillos,, Ralph; Harissi-Dagher, Mona

    2011-01-01

    Toxic reaction to nylon following uncomplicated cataract surgery and vitrectomy has been documented in the literature. We report the case of an aniridic patient with a known adverse reaction to nylon in whom Prolene suture was used in Boston Keratoprosthesis type 1 (KPro) surgery. During follow-up the cornea was checked for signs of inflammation and toxic reaction; at last follow-up (18 months) the patient showed no signs of complications due to Prolene. Our study suggests that Prolene suture...

  5. Laparoscopic fascial suture repair of parastomal hernia

    OpenAIRE

    Zia, Khawaja; McGowan, David Ross; Moore, Etienne

    2013-01-01

    Parastomal hernia is a recognised complication following stoma formation, representing a challenging problem to surgeons. At least three approaches for parastomal hernia repair have been described: fascial suture repair, relocation of stoma and local repair with use of mesh. In simple fascial suture repair only open techniques have been described. Relocation of stoma can be complicated with another parastomal hernia at the new site and risk of incisional hernia at the site of previous stoma. ...

  6. Unicoronal suture immobilization in the fetal rabbit.

    Science.gov (United States)

    Mommaerts, M Y; Caemaert, J; Dermaut, L R; Stricker, M

    2004-03-01

    Pre-clinical evaluation of surgical procedures aimed to correct craniosynostosis is ideally performed in species of small animals characterized by perinatal brain development, early skeletal maturation, and genuine synostosis in all newborns. It would be nearly impossible to breed such a colony to homozygosity, so most researchers have resorted to artificial postnatal suture immobilization. Our aim was to test the hypothesis that artificial immobilization of a unicoronal suture in the fetal rabbit (25 days of gestation) would result in neurocranial growth alterations similar to those seen in the 9-day postnatally immobilized or congenital synostotic rabbit models. The advantages of prenatal immobilization are that rabbits can undergo the tested corrective procedure at postnatal day 9. This age corresponds to a human age of 6 months and allows the deformity and the effects of its correction to be more readily detected. The heads of 25-day-old fetuses of five time-dated pregnant New Zealand white rabbits were exposed by hysterotomy. The left unicoronal suture of 4 fetuses in each litter was immobilized with a polyglactin suture piercing the frontal and parietal bone plates. The remaining two fetuses were sham-operated. Nine days after spontaneous delivery, all rabbits were marked with four titanium screws close to the sagittal and coronal sutures. Growth was recorded with dorsoventral cephalograms at 9 and 90 days. The group with the immobilized suture showed a small increase in growth across the sagittal sutures. However, the decreases in growth at the unicoronal suture in both the immobilized (5.41-mm difference with sham-treated group) and nonimmobilized (1.17-mm difference with sham-treated group) were significant. Fetal immobilization results in growth alterations similar to those observed after postnatal immobilization. PMID:15167228

  7. Massive obstetric haemorrhage following removal of a cervical suture

    OpenAIRE

    Howarth, Louise Ann; Sherliker, Sarah

    2011-01-01

    The authors present an unusual case of massive ante partum haemorrhage following removal of a cervical suture. This patient was admitted for routine removal of a McDonald’s cervical suture at 37 weeks gestation. The suture was densely adherent and after removal she suffered a haemorrhage of 2500 ml from where the suture was removed which led to fetal distress and an emergency caesarean section. The cervix was sutured and a vaginal pack inserted. During the procedure she developed hypovolaemic...

  8. Welded polypropylene liners for large descaling tanks

    Science.gov (United States)

    Abel, H. P.

    1971-01-01

    Liners for nitric and hydrofluoric acid tanks show no sign of deterioration after 18 months of continuous use. Each side of each edge of the polypropylene sheets is chamfered, and sheets are welded from both sides with polypropylene filler rod and a special hot-air welding torch.

  9. Modified method for bronchial suture by Ramirez Gama compared to separate stitches suture: experimental study

    Directory of Open Access Journals (Sweden)

    Vitor Mayer de Moura

    2014-06-01

    Full Text Available OBJECTIVE: To experimentally compare two classic techniques described for manual suture of the bronchial stump. METHODS: We used organs of pigs, with isolated trachea and lungs, preserved by refrigeration. We dissected 30 bronchi, which were divided into three groups of ten bronchi each, of 3mm, 5mm, and 7mm, respectively. In each, we performed the suture with simple, separated, extramucosal stitches in five other bronchi, and the technique proposed by Ramirez and modified by Santos et al in the other five. Once the sutures were finished, the anastomoses were tested using compressed air ventilation, applying an endotracheal pressure of 20mmHg. RESULTS: the Ramirez Gama suture was more effective in the bronchi of 3, 5 and 7 mm, and there was no air leak even after subjecting them to a tracheal pressure of 20mmHg. The simple interrupted sutures were less effective, with extravasation in six of the 15 tested bronchi, especially in the angles of the sutures. These figures were not significant (p = 0.08. CONCLUSION: manual sutures of the bronchial stumps were more effective when the modified Ramirez Gama suture was used in the caliber bronchi arms when tested with increased endotracheal pressure.

  10. Resorbable suture support for ventricular aneurysmectomy.

    Science.gov (United States)

    Vincent, J G; Skotnicki, S H; van der Meer, J J; Kubat, K

    1987-09-01

    The edge of tissue left after ventricular aneurysmectomy requires very careful placement and tying of the sutures. The use of Teflon felt as a support appears to redistribute the pressure and thus prevent the sutures from cutting through the vulnerable tissue. In many cases, Teflon felt reinforcement is preferred to direct unsupported closure because of perioperative of immediately postoperative bleeding complications. However, the unavoidable full immobilization of the sutured area, the possible risk of foreign body infection, and the extensive adhesions and calcification in the long term compelled us to search for a better alternative, combining the convenience of both methods and limiting the risks. PDS (polydioxine) resorbable pledgets and strips, provided by Ethicon GmbH, were used as a suture support during the past 2 years for closure of 29 ventricular aneurysmectomies and four ischemic ventricular septal defects, all except one in combination with coronary bypass grafting. The PDS material was easy and efficient to apply and caused no complications during and after the operation. In one case, we had the opportunity to review the supported scar during a second operation for new coronary grafts after 18 months. The formerly feared "linear scar petrification," usual after use of Teflon felt, was absent. The scar was free from difficult adhesions. Our initial experience suggests the further extensive use of this resorbable material as a support for various sutures at risk. PMID:3114566

  11. Electret Stability Related to the Crystallinity in Polypropylene

    DEFF Research Database (Denmark)

    Thyssen, Anders; Almdal, Kristoffer; Thomsen, Erik Vilain

    Through mixing isotactic-polypropylene (i-PP) and atactic-polypropylene (a-PP), we have demonstrated the importance of the crystallinity in polypropylene as an electret material. A high degree of crystallinity in polypropylene, used as an electret, gives a better charge stability towards...

  12. Natural Nanotubes Reinforcing Heterophasic Polypropylene

    Scientific Electronic Library Online (English)

    Suellem Barbosa, Cordeiro; Maria de Fátima Vieira, Marques.

    2015-04-01

    Full Text Available Nanocomposites of high-impact polypropylene resin and organosilane-functionalized nanotubes in halloysite clay were prepared with the introduction of peroxide to promote selective incorporation of the filler into the polypropylene phase of the matrix, with minor insertion into the EPR elastomeric ph [...] ase, thus improving the stiffness while preserving the high toughness of the material. Silica composites were also prepared as standard filler. The effect of increasing load content on the morphological and mechanical properties of this material was evaluated by SEM and DMA. The content of the hexane-extracted fraction of these composites after processing was evaluated. Halloysite was well-dispersed in the matrix. Composites with 10% of filler and 0.5% w/w of dicumyl peroxide had increased stiffness and higher loss factor. An increase of the E’ was generated by halloysite addition, but there was a higher decrease in Tan delta. Studies using experimental planning as a tool enabled choosing appropriate amounts of DCP to obtain a high performance composite.

  13. Cauterization technique for suture erosion in transscleralfixation of intraocular lenses

    Directory of Open Access Journals (Sweden)

    Xu-Ting Hu

    2013-12-01

    Full Text Available Transscleral suturing is a commonly applied technique to fix intraocular implants in the sulcus. A major problem after transscleral implantation is suture erosion that normally happens in the late post-surgery period and may result in an increased incidence of endophthalmitis. Here we describe an original cauterization method by using a glass rod to melt the exposed suture end without damaging the suture knot in the sclera to avoid suture exposure in sclera-fixed IOL implantation. This is a simple, quick and effective technique that can be performed without conjunctiva incisions and will help to reduce suture erosion related complications.

  14. Acute Airway Obstruction from a Suture Granuloma

    Directory of Open Access Journals (Sweden)

    Jawad Khan

    2010-03-01

    Full Text Available The complications of tracheotomy are routinely categorized from the time of operation to the onset of the complication and are thus divided into intraoperative, early, and late postoperative. A very common late complication is the development of granulation tissue. We describe a case of granulation tissue that formed around a retained silk suture obscuring about 40% of the lumen at exhalation and about 80% of the lumen with inspiration. The patient clinically experienced stridor, poor exercise tolerance, and difficulty in clearing tracheobronchial secretions. As a result, the patient required CO2 laser excision of the suture granuloma using a rigid ventilating bronchoscope and removal of the suture. We present an unusual but serious case of progressive airway obstruction.

  15. Flexor Tenorrhaphy Using Absorbable Suture Materials

    Directory of Open Access Journals (Sweden)

    Hyung Joo Kang

    2012-07-01

    Full Text Available Background Nonabsorbable sutures are favorable for repairing flexor tendons. However,absorbable sutures have performed favorably in an animal model.Methods Two-strand sutures using the interlocking modified Kessler method with polydioxanoneabsorbable sutures 4-0 were used to repair completely ruptured flexor tendons in 55 fingersfrom 41 consecutive patients. The medical records of average 42 follow up weeks were analyzedretrospectively. The data analyzed using the chi-squared test, and Fisher’s exact test was used forpostoperative complications. The results were compared with those of other studies.Results Among the index, middle, ring, and little fingers were injured in 9, 17, 16, and13 fingers, respectively. The injury levels varied from zone 1 to 5. Of the 55 digits in ourstudy, there were 26 (47% isolated flexor digitorum profundus (FDP injuries and 29 (53%combined FDP and with flexor digitorum superficialis injuries. Pulley repair was also conducted.Concomitant injuries of blood vessels and nerves were found in 17 patients (23 fingers; nerveinjuries occurred in 5 patients (10 fingers. Two patients had ruptures (3.6%, and one patienthad two adhesions (3.6%. Using the original Strickland criteria, all the patients were assessedto be excellent or good. Also, fibrosis and long-term foreign body tissue reactions such as stitchgranuloma were less likely occurred in our study. Compared to the Cullen’s report that usednonabsorbable sutures, there was no significant difference in the rupture or adhesion rates.Conclusions Therefore, this study suggests that appropriate absorbable core sutures can beused safely for flexor tendon repairs.

  16. Influence of the elastomeric polypropylene addition on the properties of commercial metallocenic polypropylene

    OpenAIRE

    Maria de Fátima V. Marques; Mariana Poloponsky; Érica Gervasoni Chaves

    2001-01-01

    Polypropylene with special properties can be obtained by metallocenic catalysts. These catalytic systems represent the beginning of a new age in polyolefins technology. In this work, the influence of the addition of a syndiotactic polypropylene (s-PP) on the processability and mechanical properties of a commercial isotactic polypropylene (i-PP) obtained by metallocenic catalysts was evaluated. Increasing addition of s-PP promoted better processability, with an increase in the impact strength ...

  17. Le choix d'un matériel de suture

    OpenAIRE

    Olivieri, Michel; Bonneau, Norbert H.

    1985-01-01

    This review summarizes the physical properties of the most frequently used suture materials. It also describes the different healing processes involved in various tissues and discusses the main points of consideration in the proper selection of a suture material.

  18. Comparison of suture types in the closure of scalp wounds.

    LENUS (Irish Health Repository)

    Bonham, Joseph

    2011-06-01

    Innovation in practice can benefit patients and healthcare providers but must be evidence based. This article describes a quantitative study of whether absorbable sutures are as beneficial as non-absorbable sutures in the management of simple scalp lacerations in adults. The results suggest that absorbable sutures can provide the same cosmetic and functional results as non-absorbable sutures. Their use can also reduce patient returns and save money and resources.

  19. Clinical Applications of Barbed Suture in Aesthetic Breast Surgery.

    Science.gov (United States)

    Mitchell, Ryan T M; Bengtson, Bradley P

    2015-10-01

    The breadth of literature regarding barbed suture applications in plastic surgical procedures and of importance to this article, barbed suture applications in breast surgery, is growing dramatically as surgical practitioners are becoming more familiar with the advantages of this new suture technology. Barbed suture devices were first implemented by plastic surgeons for the use in various minimally invasive techniques for facial rejuvenation, but have now surpassed these applications and are now much more commonly used in Breast and Body closures. PMID:26408446

  20. A modified suture technique produces consistent cerebral infarction in rats

    OpenAIRE

    Zhao, Honggang; Mayhan, William G.; Sun, Hong

    2008-01-01

    Intraluminal occlusion of the middle cerebral artery (MCA) is used extensively in cerebral ischemia research. We tested a modified nylon suture in a rat model of middle cerebral artery occlusion (MCAO) under two anesthesia regimens. Sprague-Dawley rats were divided into six groups (Group 1, Poly-L-lysine-coated suture under ketamine/xylazine anesthesia; Group 2, modified suture under ketamine/xylazine anesthesia; Group 3, Poly-L-lysine-coated suture under ketamine/xylazine anesthesia with mec...

  1. Medical quality of the radiation resistant polypropylene

    International Nuclear Information System (INIS)

    Modified polypropylene (PP-M) has been obtained in the Institute of Nuclear Research and Technology (INCT). The main component of PP-M is polypropylene MALEN P-J603, produced in Poland, with melt flow index MFR = 8,58 g/10 min (230oC/2,26 kg). PP-M material can be especially useful for medical application. Radicals which are formed during polypropylene (PP) irradiation have fundamental influence on its properties. Those radicals are located both in crystal and amorphous phase and can be respectively recognized as stable and unstable ones. The radical species formed during the irradiation of the polypropylene has been described on the base of electron spin resonance spectra. Detail investigation of medical quality of PP-M was performed. Chemical (water and hexane extract control), biological (toxicity, sterility, hemolytic properties) and physical (mechanical parameters) properties were investigated and described. (Author)

  2. [Behavior of resorbable and nonresorbable suture material in lymph vessel suture].

    Science.gov (United States)

    Baumeister, R G; Seifert, J; Wiebecke, B

    1982-01-01

    After transverse division of the abdominal thoracic duct of the rat, 14 anastomoses were performed using synthetic absorbable (Polyglactin 910, Vicryl) and synthetic non-absorbable (Polyamid 6.6, Ethilon) suture material. The anastomoses were achieved by means of a tension-free technique using interrupted sutures. The follow-up period was from 28 to 133 days. Clinical observation showed that all anastomoses were patent. However, with the aid of staining methods only five out of seven anastomoses were shown to be patent. Using absorbable suture material, a lumen was demonstrable at all anastomoses, while using non-absorbable suture material this could be proved in only four out of seven anastomoses. The foreign body reaction diminished with time when absorbable material was employed, whereas it persisted with non-absorbable material. PMID:6763587

  3. 21 CFR 878.4830 - Absorbable surgical gut suture.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Absorbable surgical gut suture. 878.4830 Section 878.4830 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... surgical gut suture. (a) Identification. An absorbable surgical gut suture, both plain and chromic, is...

  4. Horizontal running mattress suture modified with intermittent simple loops

    Directory of Open Access Journals (Sweden)

    Anna H Chacon

    2013-01-01

    Full Text Available Using the combination of a horizontal running mattress suture with intermittent loops achieves both good eversion with the horizontal running mattress plus the ease of removal of the simple loops. This combination technique also avoids the characteristic railroad track marks that result from prolonged non-absorbable suture retention. The unique feature of our technique is the incorporation of one simple running suture after every two runs of the horizontal running mattress suture. To demonstrate its utility, we used the suturing technique on several patients and analyzed the cosmetic outcome with post-operative photographs in comparison to other suturing techniques. In summary, the combination of running horizontal mattress suture with simple intermittent loops demonstrates functional and cosmetic benefits that can be readily taught, comprehended, and employed, leading to desirable aesthetic results and wound edge eversion.

  5. Aksa plans polypropylene joint venture

    International Nuclear Information System (INIS)

    Turkish acrylic fiber maker Aksa (Yalova), part of the Akkok textile conglomerate, is studying construction of a world-scale polypropylene (PP) plant as part of its diversification plans. The company says it is engaged in discussions with three 'multinations in the PP business' on the possibility of a joint venture. One of the firms is understood to be Amoco. Aksa is looking at three possible locations for the 100,000 m.t.-150,000 m.t./year plant: Yalova, near Istanbul, where its existing plants are located; Zonguldak, on the Black Sea coast; and within one of the existing complexes or a new site belonging to state-owned Petkim. Aksa has not yet discussed that option with Petkim, which recently received approval to build a $2.5-billion petrochemical complex. The Aksa PP plant would cost about $100 million and would use propylene from world markets. The onstream date depends on Aksa's ability to link up with a foreign partner, but it hopes to complete the unit within three years. Turkey has only one PP plant, a 65,000-m.t./year Petkim unit at Aliaga. The domestic market is currently two to three times that amount and is growing. Petkim also plans a 200,000-m.t./year PP plant as part of its new complex

  6. SKIN STAPLED OR SUTURED: A COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    Veerendra Kumar

    2015-01-01

    Full Text Available BACKGROUND: The choice of wound closure after a surgical procedure has been a surgeon’s dilemma . The concerns have been as to how fast , uneventful , less painful , with minimal complications and comfortable will the patient’s recovery be. A well - known technology is surgical staples which are easier to use , less time consuming and a needle free method o f wound closure. OBJECTIVE: To compare skin staples with non - absorbable skin suture for skin closure in surgical laparotomy procedures for the following character : wound infection , dehiscence , cosmesis and postoperative pain . METHODS: This is a comparative study conducted on 100 patients divided in two groups randomly at Bapuji Hospital for cases undergoing surgical laparotomy procedures. Skin closure was done with 2 - 0 polyamide skin sutures in one group and skin closure was achieved with skin staples in th e other group. The outcome of wound was assessed on 3rd , 5th and 7th postoperative days using ASEPSIS score. Wound cosmesis was assessed on the 7th postoperative day and followed up at 1st month and 3rd month , using modified Hollander cosmesis scale. Postoperative pain was assessed using the visual analogue scale on the 1st , 3rd and 7th postoperative days. RESULTS : The mean wound ASPESIS scores on day 3 for skin staples and sutured group was 0.28 and 0.36 (p=0.7 respectively. The score on day 5 for staples and sutured group was 0.12 and 0.28 (p=0.4 respectively. The results in both the groups were the same , 0.08 on day 7(p=0. Wound cosmesis mean score assessment on day 7 for skin staples suturing group was 5.84 and 5.68 respectively (p=0.3. The mean score for cosmesis assessment at 1 month , and 3 rd month for skin staples and suturing group was 5.92 and 5.68 (p=0.1 and was 6.00 and 5.92 (p=0.36 respectively which was not satistically significant . The visual analogue scale score for postopera tive pain on 1st day , 3 rd and 7 th day for skin staples and suturing group 54.0 and 68.57 (p<0.0001; 24.86 and 34.7 (p <0.0017 and 12.57 and 19.43 (p<0.0009 respectively CONCLUSIONS : Skin staples provides an effective , quicker and reliable means of skin closure and yields similar cosmetic results as with skin sutures but have less postoperative pain. The advice as to which method is used for closure of wound may come down to the cost factor , economics and surgeons preference.

  7. A century's worth of arterial sutures.

    Science.gov (United States)

    Barker, W F

    1988-01-01

    In light of the advanced state of vascular surgery today, it is hard to realize that the technique of vascular suturing is barely 100 years old. Even more remarkable is the skill with which the early surgeons applied almost all of the techniques we use today. Eck's experiments in the laboratory with portal vein-to-vena caval anastomoses were followed by pessimistic predictions concerning the future of arterial sutures. Jassinowsky had just performed the first successful arterial suture when he did a clinical arterial repair and, within 15 years, Carrel had developed nearly all the technical maneuvers which we use today. Knowledge of Carrel's work spread rapidly, and practical application of his work was reflected in the development of vascular replacements, such as venous grafting, the bypass technique used for vein grafts before World War I. There was, however, a lag in further developments until the end of the forties when dos Santos and Kunlin revived old methods and opened the way for further arterial surgical advances. These early developments are well-documented, but the reasons for delaying the acceptance of their applications remain a matter for speculation. PMID:3067741

  8. Cranial suture biology of the Aleutian Island inhabitants.

    Science.gov (United States)

    Cray, James; Mooney, Mark P; Siegel, Michael I

    2011-04-01

    Research on cranial suture biology suggests there is biological and taxonomic information to be garnered from the heritable pattern of suture synostosis. Suture synostosis along with brain growth patterns, diet, and biomechanical forces influence phenotypic variability in cranial vault morphology. This study was designed to determine the pattern of ectocranial suture synostosis in skeletal populations from the Aleutian Islands. We address the hypothesis that ectocranial suture synostosis pattern will differ according to cranial vault shape. Ales Hrdlicka identified two phenotypes in remains excavated from the Aleutian Island. The Paleo-Aleutians, exhibiting a dolichocranic phenotype with little prognathism linked to artifacts distinguished from later inhabitants, Aleutians, who exhibited a brachycranic phenotype with a greater amount of prognathism. A total of 212 crania representing Paleo-Aleuts and Aleutian as defined by Hrdlicka were investigated for suture synostosis pattern following standard methodologies. Comparisons were performed using Guttmann analyses. Results revealed similar suture fusion patterns for the Paleo-Aleut and Aleutian, a strong anterior to posterior pattern of suture fusion for the lateral-anterior suture sites, and a pattern of early termination at the sagittal suture sites for the vault. These patterns were found to differ from that reported in the literature. Because these two populations with distinct cranial shapes exhibit similar patterns of suture synostosis it appears pattern is independent of cranial shape in these populations of Homo sapiens. These findings suggest that suture fusion patterns may be population dependent and that a standardized methodology, using suture fusion to determine age-at-death, may not be applicable to all populations. PMID:21328563

  9. Cyclic viscoelastoplasticity of polypropylene/nanoclay composites

    DEFF Research Database (Denmark)

    Drozdov, A.; Christiansen, Jesper de Claville

    2012-01-01

    Observations are reported on isotactic polypropylene/organically modified nanoclay hybrids with concentrations of filler ranging from 0 to 5 wt.% in cyclic tensile tests with a stress–controlled program (oscillations between various maximum stresses and the zero minimum stress). A pronounced effect...... of nanofiller is demonstrated: reinforcement with 2 wt.% of clay results in strong reduction of maximum and minimum strains per cycle and growth of number of cycles to failure compared with neat polypropylene. To rationalize these findings, a constitutive model is developed in cyclic viscoelasticity...... crystalline phase. To assess the influence of loading conditions on the changes in the material parameters, experimental data on polypropylene are studied in cyclic tests with a strain–controlled program (oscillations between fixed maximum and minimum strains) and a mixed program (oscillations between various...

  10. Flammability of polypropylene/organoclay nanocomposites

    International Nuclear Information System (INIS)

    The flammabilities of nanocomposites made with three polypropylene grades (homo and copolymers) with 5 wt % of organoclay (Cloisite 20A), 5 or 15 wt % of maleated polypropylene as compatibilizer, and 0, 0.5 or 1 wt % of cis-13-docosenamide (Erucamide) as co-intercalant, were studied using the horizontal burning test UL94HB. Masterbatches prepared in an internal mixer were diluted in the polypropylene matrix using a corotating twin-screw extruder, with different screw configurations and operating at 240 or 480 rpm. Results indicate that the high burning rate of the composites was not affected by the processing conditions. For all formulations was observed a significant reduction in smoke release, lack of dripping and the formation of a char surface layer, that protected the core of the samples. (author)

  11. Internal friction studies of particulate filled polypropylene

    International Nuclear Information System (INIS)

    Internal friction of injection-molded polypropylene with various fractions of magnetite, barite, copper, talc, strontium ferrite and glass fibers was measured in the temperature range 170-425 K with frequencies of 0.1-100 Hz. Peaks of the ?- and ?'-relaxation were found while no peak of the ?-relaxation was detected. At high temperatures a drastic increase of the loss factor superposes the ?'-peak. The crystallinity of the filled polypropylene varies in the range from 23% to 35%. The samples consist of ?- and ?-crystallites depending on the material and amount of filler

  12. Electret Stability Related to Spherulites in Polypropylene

    DEFF Research Database (Denmark)

    Thyssen, Anders; Almdal, Kristoffer

    2015-01-01

    Electret charge stability has been related to the size of the spherulites in polypropylene. As the size of the spherulites is decreased the stability is increased. This is seen for isothermal conditions at 90 °C and 120 °C as well as for 90 % relative humidity at 50 °C. The charge release temperature is also increased in thermally stimulated voltage discharge experiments as the size of the spherulites is decreased. The size of the spherulites is controlled though the cooling rate from polypropylenes liquid state.

  13. Production and properties of polypropylene track membranes

    International Nuclear Information System (INIS)

    This paper describes the results of the method of manufacturing of the polypropylene track membranes produced by physicochemical treatment under irradiation of accelerated heavy ions of polymer films. The developed method allows one to produce membranes 0.1-0.2 ?m in diameter and more with an improved structural and physicochemical properties. Polypropylene track membranes of a novel sample are characterized by high homogeneity of pore sizes in magnitude, considerable mechanical strength, increased thermostability and resistance in aggressive media. It opens new fields for their usage. 16 refs., 5 figs., 4 tabs

  14. Electret Stability Related to Spherulites in Polypropylene

    DEFF Research Database (Denmark)

    Thyssen, Anders; Almdal, Kristoffer; Thomsen, Erik Vilain

    2015-01-01

    Electret charge stability has been related to the size of the spherulites in polypropylene. As the size of the spherulites is decreased the stability is increased. This is seen for isothermal conditions at 90 °C and 120 °C as well as for 90 % relative humidity at 50 °C. The charge release...... temperature is also increased in thermally stimulated voltage discharge experiments as the size of the spherulites is decreased. The size of the spherulites is controlled though the cooling rate from polypropylenes liquid state....

  15. Permeation of tritiated water through polypropylene

    International Nuclear Information System (INIS)

    The permeability of water through the polypropylene film was studied using tritiated water. Experiments were carried out in a flow type vessel designed for the determination of the permeability of water. All permeated water was captured by a water bubbler. The permeability was evaluated from the amount of tritiated water permeated through the polymer. The obtained apparent permeability increased with increasing temperature. The temperature dependence was governed by the water vapor pressure. The permeability of water through polypropylene normalized by water vapor pressure was found to be 1.9x10-13 g cm cm-2s-1 Torr-1 at 296 K. (author)

  16. Polypropylene mesh repair of incisional hernia

    International Nuclear Information System (INIS)

    Objective: The purpose of this study is to report the results of tension-free repair of primary and recurrent incisional hernias using polypropylene (Prolene) mesh. Results: The mean age was 43.7 years. The only death occurred in a known cirrhotic presenting with obstructed hernia. Another patient was seen developing seroma and wound infection in one case. No recurrence was seen during the mean follow-up period of 2.2 years. Conclusion: the tension-free repair of incisional hernia, with polypropylene mesh in extra facial position, is safe and easy procedure with acceptable morbidity and no recurrence. (author)

  17. The frontosphenoidal suture: fetal development and phenotype of its synostosis

    International Nuclear Information System (INIS)

    Isolated synostosis of the frontosphenoidal suture is very rare and difficult to diagnose. Little has been reported on the clinical presentation and fetal development of this suture. To understand the development of the frontosphenoidal suture and the outcome of its synostosis. We studied the normal fetal development of the frontosphenoidal suture in dry human skulls and the clinical features of four patients with isolated synostosis of the frontosphenoidal suture. The frontosphenoidal suture develops relatively late during the second trimester of pregnancy, which explains the mild phenotype when there is synostosis. This rare craniosynostosis results in a deformity that causes recession of the lateral part of the frontal bone and supraorbital rim, with minimal facial asymmetry. Three-dimensional CT is the best examination to confirm the diagnosis. Isolated frontosphenoidal synostosis should be considered in patients with unilateral flattening of the forehead at birth that does not improve within the first few months of life. (orig.)

  18. The frontosphenoidal suture: fetal development and phenotype of its synostosis

    Energy Technology Data Exchange (ETDEWEB)

    Mathijssen, Irene M.J.; Meulen, Jacques J.N.M. van der; Adrichem, Leon N.A. van; Vaandrager, J.M.; Vermeij-Keers, Christl [Erasmus MC, University Medical Centre, Department of Plastic and Reconstructive Surgery, Rotterdam (Netherlands); Hulst, Rene R.W.J. van der [University Hospital Maastricht, Department of Plastic and Reconstructive Surgery, Maastricht (Netherlands); Lequin, Maarten H. [Erasmus MC, University Medical Centre, Department of Radiology, Rotterdam (Netherlands)

    2008-04-15

    Isolated synostosis of the frontosphenoidal suture is very rare and difficult to diagnose. Little has been reported on the clinical presentation and fetal development of this suture. To understand the development of the frontosphenoidal suture and the outcome of its synostosis. We studied the normal fetal development of the frontosphenoidal suture in dry human skulls and the clinical features of four patients with isolated synostosis of the frontosphenoidal suture. The frontosphenoidal suture develops relatively late during the second trimester of pregnancy, which explains the mild phenotype when there is synostosis. This rare craniosynostosis results in a deformity that causes recession of the lateral part of the frontal bone and supraorbital rim, with minimal facial asymmetry. Three-dimensional CT is the best examination to confirm the diagnosis. Isolated frontosphenoidal synostosis should be considered in patients with unilateral flattening of the forehead at birth that does not improve within the first few months of life. (orig.)

  19. A technique for introducing looped sutures in flexor tendon repair

    Directory of Open Access Journals (Sweden)

    Kamath B

    2006-01-01

    Full Text Available Stronger flexor tendon repairs facilitate early active motion therapy protocols. Core sutures using looped suture material provide 1 ½ to twice the strength of Kessler?s technique (with four strand and six strand Tsuge technique respectively. The technique is well-described and uses preformed looped sutures (supramid. This is not available in many countries and we describe a technique whereby looped sutures can be introduced in flexor tendon repair by the use of 23 G hypodermic needle and conventional 4.0 or 5.0 sutures. This is an alternative when the custom made preformed sutures are not available. This can be practiced in zone 3 to zone 5 repairs. Technical difficulties limit its use in zone 2 repairs.

  20. Effect of Braiding and Hot Stretching Conditions on Sutures Performances

    OpenAIRE

    Faten Debbabi; Saber Ben Abdessalem

    2011-01-01

    The success of wound healing depends on suture performances, such as slippage ratio, deformation recovery, knot performance and tensile properties. The main objective of this study is to determine the effect of manufacturing parameters related to braiding and hot stretching steps on suture performances. Obtained results showed that hot stretching contributes to macromolecular chains arrangement as well as suture performances and structural properties improving. The percentage of crystallinity...

  1. Effect of electron beam radiation on the polypropylene/polyethylene blends: Radiation stabilization of polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhari, C.V. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)], E-mail: chaaudhari@yahoo.com; Dubey, K.A.; Bhardwaj, Y.K. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Naxane, G. [College of Engineering and Technology, Akola, Maharashtra (India); Sarma, K.S.S.; Sabharwal, S. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2007-10-15

    The effect of incorporation of polyethylene in the polypropylene matrix, on the radiation sensitivity of polypropylene, has been investigated. The changes in the properties such as tensile strength, elongation at break, Shore D hardness, density and melt flow index were monitored as function of polyethylene content and electron beam radiation dose. A correlation between the mechanical properties and morphology of the irradiated polymeric blends has been observed, which has been explained on the basis of Fourier-transform infrared spectroscopy, scanning electron microscope and X-ray diffraction studies. Improvement in the mechanical properties of the polypropylene, irradiated to an optimum electron beam dose, could be achieved by blending it with polyethylene >20%. The optimum radiation dose was found to be dependent on blend composition and morphology, however, an absorbed dose of 250 kGy found to be effective enough to ensure good mechanical properties of the polypropylene/polyethylene blends.

  2. Effect of electron beam radiation on the polypropylene/polyethylene blends: Radiation stabilization of polypropylene

    International Nuclear Information System (INIS)

    The effect of incorporation of polyethylene in the polypropylene matrix, on the radiation sensitivity of polypropylene, has been investigated. The changes in the properties such as tensile strength, elongation at break, Shore D hardness, density and melt flow index were monitored as function of polyethylene content and electron beam radiation dose. A correlation between the mechanical properties and morphology of the irradiated polymeric blends has been observed, which has been explained on the basis of Fourier-transform infrared spectroscopy, scanning electron microscope and X-ray diffraction studies. Improvement in the mechanical properties of the polypropylene, irradiated to an optimum electron beam dose, could be achieved by blending it with polyethylene >20%. The optimum radiation dose was found to be dependent on blend composition and morphology, however, an absorbed dose of 250 kGy found to be effective enough to ensure good mechanical properties of the polypropylene/polyethylene blends

  3. Study of metopic suture in south Indian skulls

    Directory of Open Access Journals (Sweden)

    Moula P. Akbar Basha

    2015-09-01

    Full Text Available Background: The cranial sutures and their development is the most interesting in the field of cranial growing and shaping. Metopism is partially or totally persisting suture extending from the nasion to the anterior angle of the bregma of frontal bone. Methods: Total 100 human adult dry skulls were collected from south India for present study to find out the incidence of metopic suture. Results: Out of 100 skulls, found one complete and one incomplete metopic suture. Conclusions: Present study may be useful for diagnostic and surgical intervention, particularly during frontal craniotomy. [Int J Res Med Sci 2015; 3(9.000: 2237-2239

  4. Midwives conducting perineal repair: The Danish Suture Trial

    DEFF Research Database (Denmark)

    Kindberg, Sara

    2007-01-01

    Midwives conducting perineal repair: The Danish Suture Trial.     Background Suture techniques and materials for repair of 2nd degree perineal lacerations and episiotomies have been tested in several clinical trials. Danish midwives and obstetricians have developed a new, simple and time-efficien......Midwives conducting perineal repair: The Danish Suture Trial.     Background Suture techniques and materials for repair of 2nd degree perineal lacerations and episiotomies have been tested in several clinical trials. Danish midwives and obstetricians have developed a new, simple and time......-efficient suture technique which needed systematic evaluation. Objective To compare two standardized suture techniques for perineal repair of 2nd degree perineal lacerations or episiotomies. Design and setting A double-blind randomised clinical trial conducted in Aarhus University Hospital, Denmark. Initiated...... haemorrhage >1000 ml, Diabetes, mental disorders. Both suture techniques were 2-layered using a polyglactin 910 multifilament suture (Vicryl Rapid or Vicryl). Treatment A was a continuous suture technique and treatment B was interrupted, inverted stitches. Primary outcomes: Perineal pain and wound healing...

  5. Polypropylene/aspen/liquid polybutadienes composites.

    Czech Academy of Sciences Publication Activity Database

    Kokta, B. V.; Fortelný, Ivan; Kruliš, Zden?k; Michálková, Danuše

    Erfurt : Thüringisches Institut für Textil- und Kunststoff-Forschung e.V, 2005, S1-03/1-S1-03/7. [International Symposium on Materials /5./. Erfurt (DE), 01.09.2005-02.09.2005] Institutional research plan: CEZ:AV0Z40500505 Keywords : Polymer composites * cellulose fibers * polypropylene Subject RIV: CD - Macromolecular Chemistry

  6. Toxicity of pyrolysis gases from polypropylene

    Science.gov (United States)

    Hilado, C. J.; Schneider, J. E.; Brauer, D. F.

    1979-01-01

    A sample of polypropylene was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. The gases from this sample appeared to be equivalent or less toxic than the gases from a sample of polyethylene under these particular test conditions. Carbon monoxide appeared to be the principal toxicant.

  7. Plant growth responses to polypropylene--biocontainers

    Science.gov (United States)

    The influence of bio-fillers incorporated into polypropylene (PP) on the growth of plants was evaluated. Biocontainers were created by injection molding of PP with 25-40% by weight of Osage orange tree, Paulownia tree, coffee tree wood or dried distillers grain and 5% by weight of maleated polypropy...

  8. Does UV disinfection compromise sutures? An evaluation of tissue response and suture retention in salmon surgically implanted with transmitters

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Ricardo W.; Brown, Richard S.; Deters, Katherine A.; Eppard, M. B.; Cooke, Steven J.

    2013-10-01

    Ultraviolet radiation (UVR) can be used as a tool to disinfect surgery tools used for implanting transmitters into fish. However, the use of UVR could possibly degrade monofilament suture material used to close surgical incisions. This research examined the effect of UVR on monofilament sutures to determine if they were compromised and negatively influenced tag and suture retention, incision openness, or tissue reaction. Eighty juvenile Chinook salmon Oncorhynchus tshawytscha were surgically implanted with an acoustic transmitter and a passive integrated transponder. The incision was closed with a single stitch of either a suture exposed to 20 doses of UV radiation (5 minute duration per dose) or a new, sterile suture. Fish were then held for 28 d and examined under a microscope at day 7, 14, 21 and 28 for incision openness, ulceration, redness, and the presence of water mold. There was no significant difference between treatments for incision openness, redness, ulceration or the presence of water mold on any examination day. On day 28 post-surgery, there were no lost sutures; however, 2 fish lost their transmitters (one from each treatment). The results of this study do not show any differences in negative influences such as tissue response, suture retention or tag retention between a new sterile suture and a suture disinfected with UVR.

  9. 21 CFR 878.4494 - Absorbable poly(hydroxybutyrate) surgical suture produced by recombinant DNA technology.

    Science.gov (United States)

    2010-04-01

    ...surgical suture produced by recombinant DNA technology. 878.4494 Section...surgical suture produced by recombinant DNA technology. (a) Identification...Surgical Suture Produced by Recombinant DNA Technology.” For the...

  10. Granuloma formation secondary to Achilles tendon repair with nonabsorbable suture

    OpenAIRE

    Kara, Adnan; Celik, Haluk; Seker, Ali; Uysal, Mehmet Ali; UZUN, Metin; Malkoc, Melih

    2014-01-01

    •Achilles tendon ruptures are generally observed after sport traumas and results of primary repair are good.•Several complications after surgery were reported.•In tendon repairs generally nonabsorbable sutures are used.•Ethibond suture is a strong and safe material for Achilles tendon repairs it may cause soft tissue problems such as granuloma.

  11. 21 CFR 878.4495 - Stainless steel suture.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4495 Stainless steel suture. (a...) Classification. Class II (special controls). The special control for this device is FDA's “Class II Special Controls Guidance Document: Surgical Sutures; Guidance for Industry and FDA.” See § 878.1(e) for...

  12. High-resolution sonography of the abnormal cranial suture

    Energy Technology Data Exchange (ETDEWEB)

    Soboleski, D.; Mussari, B.; McCloskey, D.; Sauerbrei, E.; Espinosa, F.; Fletcher, A. [Department of Diagnostic Radiology, Kingston General Hospital, 76 Stuart St., Kingston, Ontario K7L 2V7 (Canada)

    1998-02-01

    Objective. The purpose of this investigation is to elucidate the sonographic features of abnormal major cranial sutures. Materials and methods. Eight excised synostosed suture specimens were evaluated. The high-resolution sonographic appearance was correlated with the histological section, plain radiographs, CT and MRI. Diastatic and molded sutures were also evaluated with sonography and compared with the normal cranial suture appearance. Results. Synostosed sutures demonstrated one or more of the following features: (a) loss of echo-poor fibrous gap between bony plates (five sagittal and coronal synostoses); (b) irregular thickened inner sutural margin (three lambdoid synostoses); (c) loss of bevelled edge (one lambdoid synostosis); (d) asymmetric anterior fontanelle (one coronal synostosis). Cranial molding results in an overlap of echogenic bony plates. Sutural width (the distance between bony plates) is increased in cases of elevated intracranial pressure. Conclusion. Sonography is an inexpensive, radiation-free modality which can confirm synostosis versus molding versus an underlying intracranial lesion as a cause of plagiocephaly. The high-resolution sonographic images also provide a relatively easy means to assess sutural width and may provide information in regard to increased intracranial pressure. (orig.) With 5 figs., 12 refs.

  13. High-resolution sonography of the abnormal cranial suture

    International Nuclear Information System (INIS)

    Objective. The purpose of this investigation is to elucidate the sonographic features of abnormal major cranial sutures. Materials and methods. Eight excised synostosed suture specimens were evaluated. The high-resolution sonographic appearance was correlated with the histological section, plain radiographs, CT and MRI. Diastatic and molded sutures were also evaluated with sonography and compared with the normal cranial suture appearance. Results. Synostosed sutures demonstrated one or more of the following features: (a) loss of echo-poor fibrous gap between bony plates (five sagittal and coronal synostoses); (b) irregular thickened inner sutural margin (three lambdoid synostoses); (c) loss of bevelled edge (one lambdoid synostosis); (d) asymmetric anterior fontanelle (one coronal synostosis). Cranial molding results in an overlap of echogenic bony plates. Sutural width (the distance between bony plates) is increased in cases of elevated intracranial pressure. Conclusion. Sonography is an inexpensive, radiation-free modality which can confirm synostosis versus molding versus an underlying intracranial lesion as a cause of plagiocephaly. The high-resolution sonographic images also provide a relatively easy means to assess sutural width and may provide information in regard to increased intracranial pressure. (orig.)

  14. Reacción tisular a materiales de sutura no absorbibles en piel de equinos / Tissue reaction to nonabsorbable suture materials in horse skin

    Scientific Electronic Library Online (English)

    F, Maldonado; L, Muñoz; M, Quezada; M, Briones; P, Urrutia.

    Full Text Available Se evaluó clínica e histológicamente el grado de reacción tisular frente a cuatro materiales de sutura no absorbibles (lino, nylon, caprolactam polimerizado y polipropileno), implantados en la piel de 8 equinos. Se determinó clínicamente el edema provocado y la ausencia o presencia de exudado a los [...] 5 y 10 días de haber sido implantados los materiales de sutura, además al 10º día se realizó una biopsia para determinar histológicamente el grado de reacción tisular. Los resultados obtenidos mostraron que el lino causó un mayor edema al día 5, mientras que al día 10 el nylon y caprolactam provocaron un menor de edema. Con respecto a la presencia o ausencia de exudado, al día 5 la sutura de nylon fue la única que no presentó exudado en ninguno de los 8 ejemplares, sin embargo, al día 10, salvo un ejemplar que presentó exudado en todos los materiales, el nylon, caprolactam y polipropileno no presentaron exudado. En cuanto a la evaluación histológica tanto el nylon como el caprolactam mostraron menor grado de reacción tisular. En conclusión, el lino resultó tener el mayor grado de reacción tisular durante el presente estudio, y el nylon si bien es similar al caprolactam y polipropileno respecto a la reacción tisular, causó una menor cantidad de equinos con presencia de exudado que los otros materiales utilizados. Abstract in english The degree of tissue reaction of 4 nonabsorbable suture materials (linen, nylon, polymerized caprolactum and polypropylene) implanted into health skin of 8 horses was clinically and histologically evaluated. Cutaneous oedema and absence or presence of the exudation were clinically evaluated 5 and 10 [...] days following suture material implantation. Biopsies were taken to histologically evaluate tissue reaction at 10 days. The results obtained showed that linen caused more oedema by the 5th day, whereas the nylon and caprolactum had less oedema on the 10th day. With respect to the presence or absence of exudation, nylon was the only material which did not show exudation by the 5th day in any of the 8 samples, but on the 10th day, neither the nylon, caprolactum or polypropylene showed exudation, except one horse that showed exudation for all suture materials. The histological evaluation showed that nylon and caprolactum caused less tissue reaction. In conclusion, linen was found to have a higher degree of tissue reaction in the present study, and nylon although similar to caprolactum and polypropylene in terms of tissue reaction, caused less cases of exudate than the other suture materials used.

  15. Effect of Braiding and Hot Stretching Conditions on Sutures Performances

    Directory of Open Access Journals (Sweden)

    Faten Debbabi

    2011-01-01

    Full Text Available The success of wound healing depends on suture performances, such as slippage ratio, deformation recovery, knot performance and tensile properties. The main objective of this study is to determine the effect of manufacturing parameters related to braiding and hot stretching steps on suture performances. Obtained results showed that hot stretching contributes to macromolecular chains arrangement as well as suture performances and structural properties improving. The percentage of crystallinity of fabricated suture was ameliorated by hot stretching suture and reaches 25.51% under temperature of 170C and during 3 min. An increase of hot stretching load to 15 N reduces slippage ratio and improves percentage of deformation recovery as a consequence of the improving of macromolecular chains arrangement.

  16. Performance of antegrade suture passers according to tendon thickness

    Directory of Open Access Journals (Sweden)

    Myung-Sun Kim

    2015-01-01

    Full Text Available Purpose: To determine the effect of tendon thickness on the needle penetration ability of four different designs of antegrade suture passers. Materials and Methods: Four antegrade suture passers were tested: (a ExpresSew II (Depuy Mitek Inc., Raynham, MA, (b Arthrex Scorpion (Arthrex, Naples, FL, (c Concept (Linvatec Corp, Largo, FL, and (d ElitePass (Smith and Nephew Endoscopy, Andover, MA. Bovine tendons were divided into five thickness groups: 3, 5, 7, 9 and 11 mm. At each tendon thickness, we performed 15 trials with the suture loaded and 15 unloaded per device. Successful needle penetration was recorded, and in case of success, the exit point of the needle was noted in relation to the superior arm of the grasping component. Results: All tested suture passing devices successfully penetrated tendon thicknesses of 3 and 5 mm. With the suture loaded, one device (Concept only successfully penetrated 7 mm group tendons in 3/15 (20% trials. Success rates at 9 mm with the suture loaded were 40% in ExpresSew II, 53% in Arthrex Scorpion, 0% in Concept and 53% in ElitePass. Among successful passages with a loaded suture in the 7 and 9 mm-groups, about 20-50% of passages were oblique, and the needle came out distal to the superior arm of grasping the component. No trial with any device succeeded with 11 mm tendons in the suture loading condition. Conclusion: Using an antegrade suture passer during arthroscopic rotator cuff repair should be carefully considered when the torn end of the tendon is thicker than about 7-9 mm due to potential failure of needle penetration and/or too oblique a suture passage. Level of Evidence: Controlled laboratory study.

  17. Radiation stability of polypropylene/lead zirconate composites

    International Nuclear Information System (INIS)

    The effects of PbZrO3 filler in polypropylene were studied by isothermal and nonisothermal chemiluminescence and FT-IR spectroscopy after γ(137Cs)-irradiation at 20, 50, 100 and 250 kGy relative to neat material. For the two filler concentrations (2 and 5 wt%) the improvement in radiation stability can be noticed. The increase in the filler concentration stabilizes polypropylene matrix, whose oxidation rate decreases sharply even at 250 kGy. The interaction of polypropylene matrix with filler is discussed based on the adsorption of free radicals on zirconate particles and the electronic coupling of radiolysis intermediates and filler cations. - Highlights: • Polypropylene is more stable under gamma irradiation in the presence of lead zirconate. • Intermediate temperatures around 100 °C reveal a partial oxidation of polypropylene substrate. • Radiation stability of polypropylene compounded with lead zirconate is remarkable, leading to different applications in the manufacture of membranes

  18. Diffusion of oxygen into irradiated polypropylene films

    International Nuclear Information System (INIS)

    Polypropylene (PP) film samples were prepared using Isotactic Polypropylene (IPP) granules which were hot pressed and cooled by three different methods (annealing, quenching and water+ice and quenching liquid nitrogen) in order to obtain three different crystalline states with various thicknesses (95, 135, 150, 200 μm). These PP films were γ-irradiated with the sterilization dose of 25 kGy in vacuum at room temperature. The diffusion coefficient of oxygen into irradiated PP films were calculated by using Fick's second law of diffusion and by following the change in ESR spectra with time. It is shown that diffusion of oxygen has an inverse relation with crystallinity and film thickness. With increasing film thickness, it was observed that the diffusion coefficients of oxygen into irradiated PP film with different crystallinities were converging to a single value. (Author)

  19. Viscoelastic properties of vis-breaking polypropylenes

    Science.gov (United States)

    Nobile, Maria Rossella; Moad, Graeme; Habsuda, Jana; Li, Guoxin; Nichols, Lance; Dagley, Ian; Simon, George P.

    2015-12-01

    In this work hydrogen peroxide is used as a green initiator to cause scissioning of polypropylene (PP) with water as the only by-product replacing the organic peroxides that are usually used. The rheological properties of a commercial polypropylene and of the scissioned samples are determined by dynamic rheology and an inversion procedure for converting the linear viscoelastic data into molar mass distribution has been adopted. The results presented show that the molar mass distribution of the PP polymer is narrowed on scissioning. The process is found to produce polymers similar in molecular architecture and behavior to organic peroxide cleaved materials, the results of which are given as a comparison in this work.

  20. High strain rate behaviour of polypropylene microfoams

    OpenAIRE

    Martínez A.B.; Arencón D.; Rodríguez J.; Río T. Gómez-del; Garrido M.A.

    2012-01-01

    Microcellular materials such as polypropylene foams are often used in protective applications and passive safety for packaging (electronic components, aeronautical structures, food, etc.) or personal safety (helmets, knee-pads, etc.). In such applications the foams which are used are often designed to absorb the maximum energy and are generally subjected to severe loadings involving high strain rates. The manufacture process to obtain polymeric microcellular foams is based on the polymer satu...

  1. POLYPROPYLENE/CLAY NANOCOMPOSITES: SYNTHESIS AND CHARACTERIZATION

    OpenAIRE

    MÓNICA A PÉREZ; Bernabé L. Rivas; SADDYS M RODRÍGUEZ; ÁLVARO MALDONADO; CAROLA VENEGAS

    2010-01-01

    Polypropylene nanocomposites were synthesized by using the method of mixing in the molten state. Nanocomposites were obtained in twin-screw co-rotating extruders and the nanocomposites were prepared with percentage of nanoclay (C2) from 5 wt-%, with and without compatibilizer agent (PP-g-MA). The thermal (DSC, TGA), morphology (XRD, TEM), and dynamical mechanical (DMA) properties of the nanocomposites were characterized. All nanocomposites prepared are in intercalated state as corroborated by...

  2. 21 CFR 870.3470 - Intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or...

    Science.gov (United States)

    2010-04-01

    ... polypropylene, polyethylene terephthalate, or polytetrafluoroethylene. 870.3470 Section 870.3470 Food and Drugs... polypropylene, polyethylene terephthalate, or polytetrafluoroethylene. (a) Identification. An intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or polytetrafluoroethylene is a...

  3. Development and characterisation of injection moulded, all-polypropylene composites

    OpenAIRE

    A. Kmetty; T. Tabi; J. G. Kovacs; T. Barany

    2013-01-01

    In this work, all-polypropylene composites (all-PP composites) were manufactured by injection moulding. Prior to injection moulding, pre-impregnated pellets were prepared by a three-step process (filament winding, compression moulding and pelletizing). A highly oriented polypropylene multifilament was used as the reinforcement material, and a random polypropylene copolymer (with ethylene) was used as the matrix material. Plaque specimens were injection moulded from the pellets with either a f...

  4. Effect of stabilizers on polypropylene composition resistance to ioniozing radiation

    International Nuclear Information System (INIS)

    Full text: Polypropylene is widely used for the manufacture of medical devices and pharmaceutical packaging that is in those areas where the products are usually sterilized. Radiation emanation is used for sterilization of such products, as it is the most efficient and environmentally friendly inducstrial method. Ionizing radiation significantly affects the physical and mechanical properties of polypropylene. Study of the influence of stabilizers on radiation resistance of polypropylene-based compositions was the aim of this work

  5. High strain rate behaviour of polypropylene microfoams

    Science.gov (United States)

    Gómez-del Río, T.; Garrido, M. A.; Rodríguez, J.; Arencón, D.; Martínez, A. B.

    2012-08-01

    Microcellular materials such as polypropylene foams are often used in protective applications and passive safety for packaging (electronic components, aeronautical structures, food, etc.) or personal safety (helmets, knee-pads, etc.). In such applications the foams which are used are often designed to absorb the maximum energy and are generally subjected to severe loadings involving high strain rates. The manufacture process to obtain polymeric microcellular foams is based on the polymer saturation with a supercritical gas, at high temperature and pressure. This method presents several advantages over the conventional injection moulding techniques which make it industrially feasible. However, the effect of processing conditions such as blowing agent, concentration and microfoaming time and/or temperature on the microstructure of the resulting microcellular polymer (density, cell size and geometry) is not yet set up. The compressive mechanical behaviour of several microcellular polypropylene foams has been investigated over a wide range of strain rates (0.001 to 3000 s-1) in order to show the effects of the processing parameters and strain rate on the mechanical properties. High strain rate tests were performed using a Split Hopkinson Pressure Bar apparatus (SHPB). Polypropylene and polyethylene-ethylene block copolymer foams of various densities were considered.

  6. Effects of ?-ray irradiation on polypropylene

    International Nuclear Information System (INIS)

    The authors have found that the G-value of free radical formation by ?-ray irradiation on polyolefin depends on the higher order structure. Therefore, efforts were made to separately observe the changes in the amorphous and crystalline phases by ?-irradiation using visco-elastic measurement, differential scanning calorimetry, and X-ray method. Isotactic polypropylene was chosen as the material. The drawn and bulk samples were irradiated by ?-ray of 60Co at room temperature. Wide angle X-ray diffraction was measured to estimate the lattice constant and the halfwidth of the diffraction peak. The results obtained were discussed for the change of dynamic loss modulus E'' with temperature for the bulk samples, irradiation effects on the viscoelastic behavior of the drawn samples, and thermograms for the undrawn and drawn samples. Polypropylene has been classified as a cross-linking type polymer. In the amorphous phase, cross-linking occurs to increase the temperature location of ?a absorption. While it was found that crystal imperfection was introduced by irradiation from the illustrated facts. This crystal imperfection can be introduced by two mechanisms, (1) cross-linking formation between adjacent chains, and (2) chain scission to form chain ends. The mechanism (2) seems to be responsible for the crystal imperfection resulting in decrease of maximum temperature in polypropylene. (Wakatsuki, Y.)

  7. High strain rate behaviour of polypropylene microfoams

    Directory of Open Access Journals (Sweden)

    Martínez A.B.

    2012-08-01

    Full Text Available Microcellular materials such as polypropylene foams are often used in protective applications and passive safety for packaging (electronic components, aeronautical structures, food, etc. or personal safety (helmets, knee-pads, etc.. In such applications the foams which are used are often designed to absorb the maximum energy and are generally subjected to severe loadings involving high strain rates. The manufacture process to obtain polymeric microcellular foams is based on the polymer saturation with a supercritical gas, at high temperature and pressure. This method presents several advantages over the conventional injection moulding techniques which make it industrially feasible. However, the effect of processing conditions such as blowing agent, concentration and microfoaming time and/or temperature on the microstructure of the resulting microcellular polymer (density, cell size and geometry is not yet set up. The compressive mechanical behaviour of several microcellular polypropylene foams has been investigated over a wide range of strain rates (0.001 to 3000 s−1 in order to show the effects of the processing parameters and strain rate on the mechanical properties. High strain rate tests were performed using a Split Hopkinson Pressure Bar apparatus (SHPB. Polypropylene and polyethylene-ethylene block copolymer foams of various densities were considered.

  8. Cyclic viscoelastoplasticity of polypropylene/nanoclay composites

    DEFF Research Database (Denmark)

    Drozdov, A.; Christiansen, Jesper de Claville

    2012-01-01

    Observations are reported on isotactic polypropylene/organically modified nanoclay hybrids with concentrations of filler ranging from 0 to 5 wt.% in cyclic tensile tests with a stress–controlled program (oscillations between various maximum stresses and the zero minimum stress). A pronounced effect of nanofiller is demonstrated: reinforcement with 2 wt.% of clay results in strong reduction of maximum and minimum strains per cycle and growth of number of cycles to failure compared with neat polypropylene. To rationalize these findings, a constitutive model is developed in cyclic viscoelasticity and viscoplasticity of polymer nanocomposites. Adjustable parameters in the stress–strain relations are found by fitting experimental data. The model correctly describes the growth of the ratcheting strain and shows that fatigue failure is driven by a pronounced increase in plastic strain in the crystalline phase. To assess the influence of loading conditions on the changes in the material parameters, experimental data on polypropylene are studied in cyclic tests with a strain–controlled program (oscillations between fixed maximum and minimum strains) and a mixed program (oscillations between various maximum strains and the zero minimum stress). Numerical simulation confirms the ability of the model to predict the evolution of stress–strain diagrams with the number of cycles.

  9. Influence of the elastomeric polypropylene addition on the properties of commercial metallocenic polypropylene

    Directory of Open Access Journals (Sweden)

    Maria de Fátima V. Marques

    2001-10-01

    Full Text Available Polypropylene with special properties can be obtained by metallocenic catalysts. These catalytic systems represent the beginning of a new age in polyolefins technology. In this work, the influence of the addition of a syndiotactic polypropylene (s-PP on the processability and mechanical properties of a commercial isotactic polypropylene (i-PP obtained by metallocenic catalysts was evaluated. Increasing addition of s-PP promoted better processability, with an increase in the impact strength and a decrease in the stress at break. A reduction of the crystallinity in the polymeric blends was verified. The more significant influence of the s-PP addition was observed for the mi-PP, compared to the ZNi-PP.

  10. Influence of the elastomeric polypropylene addition on the properties of commercial metallocenic polypropylene

    Scientific Electronic Library Online (English)

    Maria de Fátima V., Marques; Mariana, Poloponsky; Érica Gervasoni, Chaves.

    2001-10-01

    Full Text Available Polypropylene with special properties can be obtained by metallocenic catalysts. These catalytic systems represent the beginning of a new age in polyolefins technology. In this work, the influence of the addition of a syndiotactic polypropylene (s-PP) on the processability and mechanical properties [...] of a commercial isotactic polypropylene (i-PP) obtained by metallocenic catalysts was evaluated. Increasing addition of s-PP promoted better processability, with an increase in the impact strength and a decrease in the stress at break. A reduction of the crystallinity in the polymeric blends was verified. The more significant influence of the s-PP addition was observed for the mi-PP, compared to the ZNi-PP.

  11. Polypropylene surface modification by entrapment of polypropylene-graft-poly(butyl methacrylate)

    International Nuclear Information System (INIS)

    Surface modification of polypropylene was carried out by entraping a copolymer of polypropylene grafted poly(butyl methacrylate) into polypropylene. The effects of structure of copolymers, contact die and content of modifiers on their surface enrichment were studied by attenuated total reflection infrared spectroscopy (ATR-FTIR), contact angle measurements and scanning electron microscopy (SEM). The results indicated that PPw-g-PBMA could diffuse preferably onto the surface and effectively increase the hydrophilicity of PP. Lower content and higher surface energy die were in favor of the copolymer to enrich on the PP surface. PPw-g-PBMA with low PBMA contents, short length of PBMA distributed in PP with smaller phase domains and favored its selective enrichment on the surface of PP, especially at lower loadings in blends. The modified material exhibited excellent solvent-resistance

  12. Polypropylene surface modification by entrapment of polypropylene-graft-poly(butyl methacrylate)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.J. [School of Chemistry and Chemical Engineering, Key Laboratory for Polymeric Composite and Functionality Materials of Education, Materials Science Institute, Sun Yat-sen University, Guangzhou 510275 (China); School of Science, Shantou University, Shantou 515063 (China); Shi, X.H. [School of Science, Shantou University, Shantou 515063 (China); Zhu, Y.F. [Instrument and Testing Center, Sun Yat-sen University, Guangzhou 510275 (China); Zhang, Y. [School of Chemistry and Chemical Engineering, Key Laboratory for Polymeric Composite and Functionality Materials of Education, Materials Science Institute, Sun Yat-sen University, Guangzhou 510275 (China); Xu, J.R. [School of Chemistry and Chemical Engineering, Key Laboratory for Polymeric Composite and Functionality Materials of Education, Materials Science Institute, Sun Yat-sen University, Guangzhou 510275 (China)], E-mail: xjr@mail.sysu.edu.cn

    2008-02-15

    Surface modification of polypropylene was carried out by entraping a copolymer of polypropylene grafted poly(butyl methacrylate) into polypropylene. The effects of structure of copolymers, contact die and content of modifiers on their surface enrichment were studied by attenuated total reflection infrared spectroscopy (ATR-FTIR), contact angle measurements and scanning electron microscopy (SEM). The results indicated that PPw-g-PBMA could diffuse preferably onto the surface and effectively increase the hydrophilicity of PP. Lower content and higher surface energy die were in favor of the copolymer to enrich on the PP surface. PPw-g-PBMA with low PBMA contents, short length of PBMA distributed in PP with smaller phase domains and favored its selective enrichment on the surface of PP, especially at lower loadings in blends. The modified material exhibited excellent solvent-resistance.

  13. Polypropylene surface modification by entrapment of polypropylene-graft-poly(butyl methacrylate)

    Science.gov (United States)

    Chen, H. J.; Shi, X. H.; Zhu, Y. F.; Zhang, Y.; Xu, J. R.

    2008-02-01

    Surface modification of polypropylene was carried out by entraping a copolymer of polypropylene grafted poly(butyl methacrylate) into polypropylene. The effects of structure of copolymers, contact die and content of modifiers on their surface enrichment were studied by attenuated total reflection infrared spectroscopy (ATR-FTIR), contact angle measurements and scanning electron microscopy (SEM). The results indicated that PPw- g-PBMA could diffuse preferably onto the surface and effectively increase the hydrophilicity of PP. Lower content and higher surface energy die were in favor of the copolymer to enrich on the PP surface. PPw- g-PBMA with low PBMA contents, short length of PBMA distributed in PP with smaller phase domains and favored its selective enrichment on the surface of PP, especially at lower loadings in blends. The modified material exhibited excellent solvent-resistance.

  14. Radiation cross-linking of montmorillonite/polypropylene composite

    International Nuclear Information System (INIS)

    Polypropylene/montmorillonite composite was prepared via melt compounding process. The dispersion of montmorillonite in the composite was analyzed by XRD (X Ray Diffraction) and TEM (Transmission Electron Microscope). Electronic radiation was applied to the composite in air. The effects of cross-linking agent and montmorillonite on polypropylene cross-linking was studied. The results indicated that cross-linking did not take place in absence of cross-linking agent, while in presence of both cross-linking agent and montmorillonite polypropylene cross-lining occurred in certain radiation dose range. The cross-linked polypropylene/montmorillonite composite exhibited improved mechanical properties. (authors)

  15. Interlocking circumareolar suture with undyed polyamide thread: a personal experience.

    Science.gov (United States)

    Salgarello, Marzia; Visconti, Giuseppe; Barone-Adesi, Liliana

    2013-10-01

    In plastic breast surgery, the interlocking areolar suture has gained wide popularity since its introduction in 2007 by Hammond and colleagues. The interlocking circumareolar suture plays its role in the setting of circumareolar excisions to achieve a durable areola shaping and to prevent scar widening/hypertrophy and areola spreading/distortion. This study retrospectively reviewed 49 breasts that underwent interlocking suture after July 2011 for both aesthetic and reconstructive indications. For the suturing, 3-0 undyed polyamide thread with a straight cutting needle (Dafilon; B. Braun Melsungen AG, Melsungen, Germany) was used. This suture material was preferred to Gore-Tex reported by Hammond and colleagues because it is undyed without any microporous configuration, more wieldy, and less expensive. All 49 breasts showed good results in terms of areola shaping and diameter control as well as good scar quality during a mean follow-up period of 12 months (range 2-18 months) (Fig. 2). No infection, suture extrusion, skin fistula, or granuloma were experienced. The suture was not visible at all, and the patients did not report its palpability. However, at careful examination, the thread resulted slightly palpable. PMID:23860820

  16. Mechanical properties of biodegradable polymer sutures coated with bioactive glass.

    Science.gov (United States)

    Stamboulis, A; Hench, L L; Boccaccini, A R

    2002-09-01

    Combining commercially available Polyglactin 910 (Vicryl) sutures with bioactive glass powder offers new possibilities for application of composite materials in tissue engineering. Commercial bioactive glass (45S5 Bioglass) powder was used to coat Vicryl sutures and the tensile strength of the sutures was tested before and after immersion in simulated body fluid (SBF) as a means to assess the effect of the bioactive glass coating on suture degradation. Different gauge lengths (126.6 and 111.6 mm) and strain rates (2.54, 11.4 and 25.4 mm/min) were tested. The tensile strength of composite sutures was slightly lower than that of as-received Vicryl sutures (404 MPa versus 463 MPa). However after 28 days immersion in SBF the residual tensile strength of the coated sutures was significantly higher, indicating a protective function of the Bioglass coating. The tensile strength results were similar for the different gauge lengths and strain rates investigated. A qualitative explanation for the effect of bioactive glass coating on polymer degradation is offered. PMID:15348548

  17. Complications with mechanical suture use in colorectal surgery

    International Nuclear Information System (INIS)

    The great development of mechanical suture and its qualitative impact in colorectal surgery has not been able to avoid persistent mortality due to suture failure which is still about 5% and rectal stenosis, which is significantly higher than with manual sutures.The present paper analyses 63 cases of colorrectal anastomosis performed of coordination with mechanical suture at CASMU, in a period of four years (1991-1995).There were 51 rectum resections and colorrectal anastomosis and 12 reconstruction of intestinal transit.There were 28 females and 35 males with and average age of 66 years.Three patients died (4,7%), 20 (31,7%) suffered various complications among which some are pointed out in relation to mechanical suture to suture failures(3,1%) who died and 8 rectal stenosis(12,9%)with favourable evolution after dilations.The authors analyse the issues that incide on the production of complications in colorrectal surgery and conclude that the incidence of global complications in their series is elevated, although mortality, suture failure and rectal stenosis figures are comparable to those in international literature analysed.The incidence of machine width proximal ostomies and radiotherapy on the development of stenosis in our milieu require a multicentric studie with a greater number of patients

  18. A multiphase transitioning peptide hydrogel for suturing ultrasmall vessels

    Science.gov (United States)

    Smith, Daniel J.; Brat, Gabriel A.; Medina, Scott H.; Tong, Dedi; Huang, Yong; Grahammer, Johanna; Furtmüller, Georg J.; Oh, Byoung Chol; Nagy-Smith, Katelyn J.; Walczak, Piotr; Brandacher, Gerald; Schneider, Joel P.

    2016-01-01

    Many surgeries are complicated by the need to anastomose, or reconnect, micrometre-scale vessels. Although suturing remains the gold standard for anastomosing vessels, it is difficult to place sutures correctly through collapsed lumen, making the procedure prone to failure. Here, we report a multiphase transitioning peptide hydrogel that can be injected into the lumen of vessels to facilitate suturing. The peptide, which contains a photocaged glutamic acid, forms a solid-like gel in a syringe and can be shear-thin delivered to the lumen of collapsed vessels (where it distends the vessel) and the space between two vessels (where it is used to approximate the vessel ends). Suturing is performed directly through the gel. Light is used to initiate the final gel–sol phase transition that disrupts the hydrogel network, allowing the gel to be removed and blood flow to resume. This gel adds a new tool to the armamentarium for micro- and supermicrosurgical procedures.

  19. Brief communication: Ectocranial suture closure in Pongo: pattern and phylogeny.

    Science.gov (United States)

    Cray, James; Cooper, Gregory M; Mooney, Mark P; Siegel, Michael I

    2010-11-01

    Ectocranial suture fusion patterns have been shown to contain biological and phylogenetic information. Previously the patterns of Homo, Pan, and Gorilla have been described. These data reflect the phylogenetic relationships among these species. In this study, we applied similar methodology to Pongo to determine the suture synostosis progression of this genus, and to allow comparison to previously reported data on other large-bodied hominoids. We hypothesized these data would strengthen the argument that suture synostosis patterns reflect the phylogeny of primate taxa. Results indicate that the synostosis of vault sutures in Pongo is similar to that reported for Gorilla (excluding Pan and Homo). However, the lateral-anterior pattern of fusion, in which there is a strong superior to inferior pattern, for Pongo is unique among these species, reflecting its phylogenetic distinctness among great ape taxa. PMID:20721941

  20. Ab initio study of semiconductor atoms impurities in zigzag edge (10,0) carbon nanotubes

    Science.gov (United States)

    Muttaqien, Fahdzi; Suprijadi

    2015-04-01

    The substitutional impurities in zigzag edge (10,0) carbon nanotubes have been studied by using first principles calculations. Silicon (Si), gallium (Ga), and arsenic (As) atom have been chosen as semiconductor based-atom for replacing carbon atoms in CNT's surface. The silicon atom changes the energy gap of pristine zigzag (10,0) CNT, it is 0.19 eV more narrow than that of pristine CNT. Geometrically, the silicon atom creates sp3 bond with three adjacent carbon atoms, where the tetrahedral form of its sp3 bond is consisted of free unoccupied state. The silicon atom does not induce magnetism to zigzag CNT. Due to gallium (Ga) and arsenic (As) atom substitution, the zigzag CNT becomes metallic and has magnetic moment of 1 µB. The valance and conduction band are crossed each other, then the energy gap is vanished. The electronic properties of GaAs-doped CNT are dominantly affected by gallium atom and its magnetic properties are dominantly affected by arsenic atom. These results prove that the CNT with desired properties can be obtained with substitutional impurities without any giving structural defect.

  1. Ab initio study of semiconductor atoms impurities in zigzag edge (10,0) carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Muttaqien, Fahdzi, E-mail: fahdzi@cphys.fi.itb.ac.id; Suprijadi, E-mail: supri@fi.itb.ac.id [Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung Ganeca 10, Bandung 40132 (Indonesia)

    2015-04-16

    The substitutional impurities in zigzag edge (10,0) carbon nanotubes have been studied by using first principles calculations. Silicon (Si), gallium (Ga), and arsenic (As) atom have been chosen as semiconductor based-atom for replacing carbon atoms in CNT’s surface. The silicon atom changes the energy gap of pristine zigzag (10,0) CNT, it is 0.19 eV more narrow than that of pristine CNT. Geometrically, the silicon atom creates sp{sup 3} bond with three adjacent carbon atoms, where the tetrahedral form of its sp{sup 3} bond is consisted of free unoccupied state. The silicon atom does not induce magnetism to zigzag CNT. Due to gallium (Ga) and arsenic (As) atom substitution, the zigzag CNT becomes metallic and has magnetic moment of 1?µ{sub B}. The valance and conduction band are crossed each other, then the energy gap is vanished. The electronic properties of GaAs-doped CNT are dominantly affected by gallium atom and its magnetic properties are dominantly affected by arsenic atom. These results prove that the CNT with desired properties can be obtained with substitutional impurities without any giving structural defect.

  2. Ophiolite belts in the sw-iberian variscan suture

    OpenAIRE

    Ribeiro, António; Pedro, Jorge; Tassinari, Colombo; Munhá, José; Araújo, Alexandre; Fonseca, Paulo; Mateus, António; Gil, Pedro

    2008-01-01

    The SW-Iberia Variscan suture is the boundary between the Iberian (IT) and the South-Portuguese (SPT) Terranes, materializing the closure of Rheic and related oceans by northeast ward subduction of the SPT under the IT. The western segment of this suture displays imbrications of various units belonging to: (1) Neoproterozoic - Lower Palaeozoic Ossa Morena Zone (OMZ) relative autochthonous (locally covered by Lower-Middle Devonian limestones and shales); and (2) allochthonous complexes. The la...

  3. Mechanical force-induced midpalatal suture remodeling in mice

    OpenAIRE

    Hou, Bo; Fukai, Naomi; Olsen, Bjorn R

    2007-01-01

    Mechanical stress is an important epigenetic factor for regulating skeletal remodeling, and application of force can lead to remodeling of both bone and cartilage. Chondrocytes, osteoblasts and osteoclasts all participate and interact with each other in this remodeling process. To study cellular responses to mechanical stimuli in a system that can be genetically manipulated, we used mouse midpalatal suture expansion in vivo. 6-weeks-old male C57BL/6 mice were subjected to palatal suture expan...

  4. Experimental evaluation of horse hair as a nonabsorbable monofilament suture

    Directory of Open Access Journals (Sweden)

    Swati R Yedke

    2013-01-01

    Full Text Available Background: Success of surgery depends on wound closure and healing. Ancients had coated many suture materials from plant and animal origin. As the quest for natural nonabsorbable, monofilament surgical suture continues, horsehair has been taken for study, which is mentioned in ancient literature. Objectives: Aim of the study was to evaluate detail mechanical and biophysical properties of horsehair. Materials and Methods: Physical properties, that are diameter, straight pull and knot pull tensile strength, bioburden, sterility tests were performed. Visual and histological wound healing parameters were studied in experimental Wistar rat incision wound model. Two experimental wounds about 5 cm long were created on each side of dorsal midline. Each animal received two sutures-Horsehair 4-0 and Ethilon 4-0. The sutured areas were grossly examined on 3 rd and 7 th days for visual observations like congestion, edema, infection, wound disruption, and impression of suture material on healed wound and then subjected for histological study. Results: Revealed that horsehair has got diameter of 0.19 mm which complies with the 4-0 size USP standard. Straight pull tensile strength was found 0.5851 ± 0.122 kg and knot pull tensile strength was 0.3998 ± 0.078 kg, which complies with the standards of United State Pharmacopia for class II nonabsorbable suture materials. In vivo study revealed that there was no evidence of edema, congestion, and discharge in both the groups. Wounds healed with minimum impressions of suture material with minimum scar mark. Mean histological scoring shows very mild tissue reaction. Conclusion: Horsehair has got properties of standard suture material except low tensile strength and hence can be used in reconstructive, plastic surgeries, and ophthalmic surgeries.

  5. Scar tissue orientation in unsutured and sutured corneal wound healing.

    OpenAIRE

    Melles, G R J; Binder, P.S.; Houdijn Beekhuis, W.; Wijdh, R.H.J.; Moore, M N; Anderson, J. A.; SundarRaj, N.

    1995-01-01

    AIMS--This study aimed to evaluate stromal wound healing morphology in short term unsutured compared with sutured corneal wounds, to define regional variation in healing within radial keratotomy wounds. METHODS--Stromal scar tissue orientation (fibroblast and collagen fibre orientation) was analysed in unsutured and adjacent sutured keratotomy wounds in monkeys, 2 to 9 weeks after surgery, using light and transmission electron microscopy. RESULTS--At 2 to 4 weeks, scar tissue orientation was ...

  6. Explosive spalling of concrete, the mitigating effect of Polypropylene Fibres

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt

    2003-01-01

    This paper briefly describes the main results of a recent investigation on the influence of polypropylene fibres and restraint on the susceptibility of concrete to explosive spalling at high temperatures. The results suggest that polypropylene fibres may prevent spalling in both unstrained and...

  7. Explosive spalling of concrete, the mitigating effect of Polypropylene Fibres

    DEFF Research Database (Denmark)

    SØrensen, Lars SchiØtt Technical University of Denmark,

    2003-01-01

    This paper briefly describes the main results of a recent investigation on the influence of polypropylene fibres and restraint on the susceptibility of concrete to explosive spalling at high temperatures. The results suggest that polypropylene fibres may prevent spalling in both unstrained and restrained structures.

  8. Characterization of flame retardant polypropylene-magnesium hydroxide composite foams

    OpenAIRE

    Sousa Pais Antunes, Marcelo de; Haurie Ibarra, Laia; Velasco Perero, José Ignacio

    2009-01-01

    Magnesium hydroxide filled polypropylene foams have been prepared in order to analyze the foaming effects on the microstructure, flame and thermo-mechanical beaviour of the polypropylene composites. Several load percentages as well as foam densities were considered. Results are discussed in terms of the observed dynamic-mechanical thermal analysis and flame behaviour.

  9. Development of braided drug-loaded nanofiber sutures

    Energy Technology Data Exchange (ETDEWEB)

    Hu Wen [School of Materials Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Huang Zhengming [School of Aerospace Engineering and Applied Mechanics, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Liu Xiangyang, E-mail: huangzm@tongji.edu.cn [Department of Physics, National University of Singapore, 2 Science Drive 3, 117542 (Singapore)

    2010-08-06

    The objectives of this work are twofold. Firstly, while most work on electrospinning is limited to the development of only functional materials, a structural application of electrospun nanofibers is explored. Secondly, a drug-loaded tissue suture is fabricated and its various properties are characterized. Braided drug-loaded nanofiber sutures are obtained by combining an electrospinning process with a braiding technique followed by a coating procedure. Two different electrospinning techniques, i.e. blend and coaxial electrospinning, to incorporate a model drug cefotaxime sodium (CFX-Na) into poly(L-lactic acid) (PLLA) nanofibers have been applied and compared with each other. Properties of the braided drug-loaded sutures are characterized through a variety of methods including SEM, TEM and tensile testing. The results show that the nanofibers had a preferable micromorphology. The drug was incorporated into the polymer nanofibers homogeneously, with no cross-linking. The nanofibers maintained their fibrous structures. An in vitro release study indicates that the drug-loaded nanofibers fabricated by blend electrospinning and coaxial electrospinning had a different drug release behavior. An inhibition zone experiment shows that both sutures obtained from the nanofibers of the different electrospinning techniques had favorable antibacterial properties. The drug-loaded sutures had preferable histological compatibility performance compared with commercial silk sutures in an in vivo comparative study.

  10. Development of braided drug-loaded nanofiber sutures

    International Nuclear Information System (INIS)

    The objectives of this work are twofold. Firstly, while most work on electrospinning is limited to the development of only functional materials, a structural application of electrospun nanofibers is explored. Secondly, a drug-loaded tissue suture is fabricated and its various properties are characterized. Braided drug-loaded nanofiber sutures are obtained by combining an electrospinning process with a braiding technique followed by a coating procedure. Two different electrospinning techniques, i.e. blend and coaxial electrospinning, to incorporate a model drug cefotaxime sodium (CFX-Na) into poly(L-lactic acid) (PLLA) nanofibers have been applied and compared with each other. Properties of the braided drug-loaded sutures are characterized through a variety of methods including SEM, TEM and tensile testing. The results show that the nanofibers had a preferable micromorphology. The drug was incorporated into the polymer nanofibers homogeneously, with no cross-linking. The nanofibers maintained their fibrous structures. An in vitro release study indicates that the drug-loaded nanofibers fabricated by blend electrospinning and coaxial electrospinning had a different drug release behavior. An inhibition zone experiment shows that both sutures obtained from the nanofibers of the different electrospinning techniques had favorable antibacterial properties. The drug-loaded sutures had preferable histological compatibility performance compared with commercial silk sutures in an in vivo comparative study.

  11. Sutured tendon repair; a multi-scale finite element model.

    Science.gov (United States)

    Rawson, Shelley D; Margetts, Lee; Wong, Jason K F; Cartmell, Sarah H

    2015-01-01

    Following rupture, tendons are sutured to reapproximate the severed ends and permit healing. Several repair techniques are employed clinically, with recent focus towards high-strength sutures, permitting early active mobilisation thus improving resultant joint mobility. However, the arrangement of suture repairs locally alters the loading environment experienced by the tendon. The extent of the augmented stress distribution and its effect on the tissue is unknown. Stress distribution cannot be established using traditional tensile testing, in vivo, or ex vivo study of suture repairs. We have developed a 3D finite element model of a Kessler suture repair employing multiscale modelling to represent tendon microstructure and incorporate its highly orthotropic behaviour into the tissue description. This was informed by ex vivo tensile testing of porcine flexor digitorum profundus tendon. The transverse modulus of the tendon was 0.2551 ± 0.0818 MPa and 0.1035 ± 0.0454 MPa in proximal and distal tendon samples, respectively, and the interfibrillar tissue modulus ranged from 0.1021 to 0.0416 MPa. We observed an elliptically shaped region of high stress around the suture anchor, consistent with a known region of acellularity which develop 72 h post-operatively and remain for at least a year. We also observed a stress shielded region close to the severed tendon ends, which may impair collagen fibre realignment during the remodelling stage of repair due to the lack of tensile stress. PMID:24840732

  12. Iatrogenic Ulnar Nerve Injury post Laceration Suturing – An Unusual Presentation

    Directory of Open Access Journals (Sweden)

    Murali Mothilal

    2013-07-01

    Full Text Available Introduction: Nerve entrapment while suturing a lacerated wound is a complication that is easily avoidable. We report a case low ulnar nerve palsy due to nerve entrapment while suturing a lacerated wound. Case Report: A 48 year old lady came with complaints of pain and a lacerated wound over the dorsomedial aspect of lower third of the left forearm. The lacerated wound was sutured elsewhere one week back. She had fracture of lower third of the ulna which was stabilised with plates and screws using a separate dorsal incision. She developed ulnar claw hand on the third postoperative day. Strength duration curve revealed neurotmesis of ulnar nerve. Ulnar nerve exploration was done and the nerve was found to be ligated at the site of original laceration. The ligature was released and nerve was found to be thinned out at the site. There was no neurological recovery at 5 months follow up and reconstruction procedures in form of tendon tranfer are planned for the patient. Conclusion: This is a case of iatrogenic ulnar nerve palsy which is very rare in our literature. This can be easily avoided if proper care is taken while suturing the primary laceration. A nerve can be mistakenly sutured for a bleeding vein and proper exposure while suturing will be necessary especially at areas where nerves are superficial. Keywords: Iatrogenic, ulnar nerve palsy

  13. The nonlinear viscoelastic behavior of polypropylene

    CERN Document Server

    Drozdov, A D

    2002-01-01

    A series of tensile relaxation tests is performed on isotactic polypropylene in the sub-yield and post-yield regions at room temperature. Constitutive equations are derived for the time-dependent response of a semicrystalline polymer at isothermal loading with small strains. Adjustable parameters in the stress-strain relations are found by fitting experimental data. It is demonstrated that the growth of the longitudinal strain results in an increase in the relaxation rate in a small interval of strains in the sub-yield domain. When the strain exceeds some critical value which is substantially less than the apparent yield strain, the relaxation process becomes strain-independent.

  14. Crystallization of polypropylene at high cooling rates

    OpenAIRE

    Boyer, Séverine A.E.; Haudin, Jean-Marc

    2009-01-01

    In the context of polymer crystallization under high and constant cooling rates, a new survey is presented. The growth kinetics of spherulites from the molten state and the corresponding temperature of crystallization under similar cooling rates are considered. An industrial grade of isotactic polypropylene (iPP) is investigated in the range of slow (from 1 to 10°C/min), of relatively moderate (from 30 to 500°C/min) and of high (from 500 to 1600°C/min) constant cooling rates. The growth kinet...

  15. Biopolymer synthesis on polypropylene supports: oligonucleotide arrays.

    Science.gov (United States)

    Matson, R S; Rampal, J; Pentoney, S L; Anderson, P D; Coassin, P

    1995-01-01

    High-density oligonucleotide arrays have been constructed on clear, aminated polypropylene film using conventional phosphoramidite-based synthesis chemistries. A semiautomated 64-channel fluidic chemical delivery system is used to prepare the 64 x 64 array containing 4096 oligonucleotide elements. The completed array has been successfully used in the hybridization and fluorescence (Streptavidin-FITC) detection of a biotinylated 18-mer oligonucleotide target complementary to the F508 codon region of the cystic fibrosis transmembrane conductance regulator gene. A hybridization simulation model based upon Nearest Neighbor approximations is used to predict the outcome of the array hybridization experiment. PMID:7710056

  16. Craniosynostosis of coronal suture in Twist1+/- mice occurs through endochondral ossification recapitulating the physiological closure of posterior frontal suture

    Directory of Open Access Journals (Sweden)

    NatalinaQuarto

    2011-07-01

    Full Text Available Craniosynostosis, the premature closure of cranial suture, is a pathologic condition that affects 1/2000 live births. Saethre-Chotzen syndrome is a genetic condition characterized by craniosynostosis. The Saethre-Chotzen syndrome, which is defined by loss-of-function mutations in the TWIST gene, is the second most prevalent craniosynostosis. Although much of the genetics and phenotypes in craniosynostosis syndromes is understood, less is known about the underlying ossification mechanism during suture closure. We have previously demonstrated that physiological closure of the posterior frontal (PF suture occurs through endochondral ossification. Moreover, we revealed that antagonizing canonical Wnt signaling in the sagittal suture leads to endochondral ossification of the suture mesenchyme and sagittal synostosis, presumably by inhibiting Twist1. Classic Saethre-Chotzen syndrome is characterized by coronal synostosis, and the haploinsufficient Twist1+/- mice represents a suitable model for studying this syndrome. Thus, we seeked to understand the underlying ossification process in coronal craniosynostosis in Twist1+/- mice. Our data indicate that coronal suture closure in Twist1+/- mice occurs between postnatal day 9 to 13 by endochondral ossification, as shown by histology, gene expression analysis and immunohistochemistry. In conclusion, this study reveals that coronal craniosynostosis in Twist1+/- mice occurs through endochondral ossification. Moreover, it suggests that haploinsufficency of Twist1 gene, a target of canonical Wnt-signaling, and inhibitor of chondrogenesis, mimics conditions of inactive canonical Wnt-signaling leading to craniosynostosis.

  17. Improved oil spill recovery using polypropylene fabric

    International Nuclear Information System (INIS)

    An active boom for recovering oil spills was tested in a tank with diesel fuel, a motor oil, and a heavy crude oil. The boom consisted of a porous pipe wrapped in a polypropylene fabric to which a vacuum was applied. The diesel was recovered at a rate of 29 gal/h per ft2 of fabric surface area (GHPF) using a vacuum of 17 in. of water without any entrained water. The motor oil was recovered at a rate of 2.5 GHPF using a vacuum of 20 in. of water without any entrained water. The crude oil test at a vacuum of 8 in. Hg also resulted in a fluid recovery rate of 2.5 GHPF, but half of the recovered fluid was water. The results suggest that a device presenting a large surface area of polypropylene fabric to a spill of light or medium oil will separate the oil from the water. Uses for the device extend to other situations where oil-water separation is required. 1 ref., 4 figs., 3 tabs

  18. Radiation induced grafting of TMPM onto polypropylene

    International Nuclear Information System (INIS)

    The gamma radiation induced graft copolymerization of 2,2,6,6-tetramethyl-4-piperidinyl-methacrylate (TMPM), a very effective hindered amine light stabilizer (HALS), onto polypropylene was investigated by simultaneous-irradiation technique. the effects of various synthesis conditions on the graft content were studied. It was shown that percent grafting in benzene, CCl4 and petroleum ether were higher than that in other solvents. The percent grafting was higher when graft copolymerization was carried out in argon atmosphere than that in air. For the grafting copolymerization carried out in benzene, percent grafting increased linearly from 10 to 60 kGy and beyond 60 kGy a tendency to level off was appeared. In CCl4, percent grafting increased linearly from 10 to 50 kGy and beyond 50 kGy a tendency to level off was appeared. Percent grafting also increased continuously with increasing monomer concentration up to 2.85 mol/L, but significant increase was observed only up to 1.14 mol/L. the percent grafting decreased when inhibitor was used, the difference of percent grafting between the samples with and without inhibitor became smaller with the increase of irradiation dose. The stabilizing effectiveness of grafted TMPM on the radiation resistance of Polypropylene was found to be better than that of TMPM monomer

  19. Diffuse reflectance spectrophotometry in polypropylene radiolysis study

    International Nuclear Information System (INIS)

    Application of diffuse reflectance spectrophotometry (DRS) in the investigation of stable and semi-stable products of radiolysis in solid state radiation chemistry creates the possibility of spectrophotometric measurements in the case of opaque objects of investigation, e.g. virgin polypropylene in powder. The main advantages of the method are: (1) the object of investigation may be used in any physical shape (hardly transparent films, opaque powders); (2) The measurement is non destructive; (3) No solvents which could influence transients and final products of radiolysis are necessary; (4) Only optical spectra (200-1000 nm) of intermediate species and final products created during irradiation are observed, since unirradiated sample is used as the reference; (5) the method is complementary to EPR, because it shows spectra of not paramagnetic species, which do not give EPR signals. Numerous spectra of irradiated polypropylene have been recorded, some of them have been identified as due to peroxides. Others remain to be identified or are waiting to be the subject of working hypotheses. (author)

  20. Effects of gamma irradiation on polypropylene, polypropylene + high density polyethylene and polypropylene + high density polyethylene + wood flour

    International Nuclear Information System (INIS)

    The effect of the gamma-irradiation on the mechanical properties of the composites, Polypropylene (PP), PP+high density Polyethylene (HDPE), PP+ HDPE+wood flour, where HDPE is virgin and recycled, was studied. This paper discusses the behavior of the composites after exposure to various doses of gamma irradiation (1-7 MRads) in the presence of oxygen. The dependence of mechanical properties on the integral dose for a constant dose rate of 0.48 MRads/h confirms the influence of the irradiation. Strong effects on the elongation at break and break strength is noticed. The mathematical analysis suggests for the PP+r-HDPE a bimolecular process of the elongation at break. On the order hand, for the PP+HDPE a complex process is represented for a three exponential equation. (orig.)

  1. Effect of recombinant human platelet-derived growth factor-BB-coated sutures on Achilles tendon healing in a rat model: A histological and biomechanical study

    Directory of Open Access Journals (Sweden)

    Stephen H Cummings

    2012-07-01

    Full Text Available Purpose: Repairing tendon injuries with recombinant human platelet-derived growth factor-BB has potential for improving surgical outcomes. Augmentation of sutures, a critical component of surgical tendon repair, by coating with growth factors may provide a clinically useful therapeutic device for improving tendon repair. Therefore, the purpose of this study was to (a coat Vicryl sutures with a defined dose of recombinant human platelet-derived growth factor-BB without additional coating excipients (e.g. gelatin, (b quantify the recombinant human platelet-derived growth factor-BB released from the suture, and (c use the recombinant human platelet-derived growth factor-BB-coated sutures to enhance tendon repair in a rat Achilles tendon transection model. Methods: Vicryl sutures were coated with 0, 0.3, 1.0, and 10.0 mg/mL concentrations of recombinant human platelet-derived growth factor-BB using a dip-coating process. In vitro release was quantified by an enzyme-linked immunosorbent assay. Acutely transected rat Achilles tendons were repaired using one of the four suture groups (n = 12 per group. Four weeks following repair, the tensile biomechanical and histological (i.e. collagen organization and angiogenesis properties were determined. Results: A dose-dependent bolus release of recombinant human platelet-derived growth factor-BB occurred within the first hour in vitro, followed by a gradual release over 48 h. There was a significant increase in ultimate tensile strength (p < 0.01 in the two highest recombinant human platelet-derived growth factor-BB dose groups (1.9 ± 0.5 and 2.1 ± 0.5 MPa relative to controls (1.0 ± 0.2 MPa. The modulus significantly increased (p = 0.031 with the highest recombinant human platelet-derived growth factor-BB dose group (7.2 ± 3.8 MPa relative to all other groups (control: 3.5 ± 0.9 MPa. No significant differences were identified for the maximum load or stiffness. The histological collagen and angiogenesis scores were comparable in all groups, although there was a trend for improved collagen organization in the recombinant human platelet-derived growth factor-BB-treated groups (p = 0.054. Conclusions: The results of this study suggest that recombinant human platelet-derived growth factor-BB can be used to reproducibly coat Vicryl sutures and improve remodeling in a rat Achilles tendon transection model by significantly decreasing the resulting cross-sectional area, thus improving the material properties of the repaired tendon.

  2. Effect of recombinant human platelet-derived growth factor-BB-coated sutures on Achilles tendon healing in a rat model: A histological and biomechanical study

    Science.gov (United States)

    Cummings, Stephen H; Grande, Daniel A; Hee, Christopher K; Kestler, Hans K; Roden, Colleen M; Shah, Neil V; Razzano, Pasquale; Dines, David M; Chahine, Nadeen O

    2012-01-01

    Purpose: Repairing tendon injuries with recombinant human platelet-derived growth factor-BB has potential for improving surgical outcomes. Augmentation of sutures, a critical component of surgical tendon repair, by coating with growth factors may provide a clinically useful therapeutic device for improving tendon repair. Therefore, the purpose of this study was to (a) coat Vicryl sutures with a defined dose of recombinant human platelet-derived growth factor-BB without additional coating excipients (e.g. gelatin), (b) quantify the recombinant human platelet-derived growth factor-BB released from the suture, and (c) use the recombinant human platelet-derived growth factor-BB-coated sutures to enhance tendon repair in a rat Achilles tendon transection model. Methods: Vicryl sutures were coated with 0, 0.3, 1.0, and 10.0 mg/mL concentrations of recombinant human platelet-derived growth factor-BB using a dip-coating process. In vitro release was quantified by an enzyme-linked immunosorbent assay. Acutely transected rat Achilles tendons were repaired using one of the four suture groups (n = 12 per group). Four weeks following repair, the tensile biomechanical and histological (i.e. collagen organization and angiogenesis) properties were determined. Results: A dose-dependent bolus release of recombinant human platelet-derived growth factor-BB occurred within the first hour in vitro, followed by a gradual release over 48 h. There was a significant increase in ultimate tensile strength (p < 0.01) in the two highest recombinant human platelet-derived growth factor-BB dose groups (1.9 ± 0.5 and 2.1 ± 0.5 MPa) relative to controls (1.0 ± 0.2 MPa). The modulus significantly increased (p = 0.031) with the highest recombinant human platelet-derived growth factor-BB dose group (7.2 ± 3.8 MPa) relative to all other groups (control: 3.5 ± 0.9 MPa). No significant differences were identified for the maximum load or stiffness. The histological collagen and angiogenesis scores were comparable in all groups, although there was a trend for improved collagen organization in the recombinant human platelet-derived growth factor-BB-treated groups (p = 0.054). Conclusions: The results of this study suggest that recombinant human platelet-derived growth factor-BB can be used to reproducibly coat Vicryl sutures and improve remodeling in a rat Achilles tendon transection model by significantly decreasing the resulting cross-sectional area, thus improving the material properties of the repaired tendon. PMID:22798983

  3. Recognizing surgeon's actions during suture operations from video sequences

    Science.gov (United States)

    Li, Ye; Ohya, Jun; Chiba, Toshio; Xu, Rong; Yamashita, Hiromasa

    2014-03-01

    Because of the shortage of nurses in the world, the realization of a robotic nurse that can support surgeries autonomously is very important. More specifically, the robotic nurse should be able to autonomously recognize different situations of surgeries so that the robotic nurse can pass necessary surgical tools to the medical doctors in a timely manner. This paper proposes and explores methods that can classify suture and tying actions during suture operations from the video sequence that observes the surgery scene that includes the surgeon's hands. First, the proposed method uses skin pixel detection and foreground extraction to detect the hand area. Then, interest points are randomly chosen from the hand area so that their 3D SIFT descriptors are computed. A word vocabulary is built by applying hierarchical K-means to these descriptors, and the words' frequency histogram, which corresponds to the feature space, is computed. Finally, to classify the actions, either SVM (Support Vector Machine), Nearest Neighbor rule (NN) for the feature space or a method that combines "sliding window" with NN is performed. We collect 53 suture videos and 53 tying videos to build the training set and to test the proposed method experimentally. It turns out that the NN gives higher than 90% accuracies, which are better recognition than SVM. Negative actions, which are different from either suture or tying action, are recognized with quite good accuracies, while "Sliding window" did not show significant improvements for suture and tying and cannot recognize negative actions.

  4. Polypropylene and polycarbonate radiosterilization: effects on the stress resistance

    International Nuclear Information System (INIS)

    The gamma radiation effect on polymer sterilization used in the fabrication of medical supplies, national polycarbonate and polypropylene, was studied in function of the tensile strength. During the polycarbonate irradiation occur the scission of polymer chain and the crosslinking/scission of the polypropylene, but in the sterilization dose, 25 kGy, does not occur expressive changes in the tensile strength. After the polypropylene sterilization the tensile strength continues increasing as consequence of the crosslinking. Since the sixth day the oxidation reaction predominates as consequence of the radical migration to the amorphous region. (author). 7 refs, 6 figs

  5. Fatigue mechanisms in unidirectional glass-fibre-reinforced polypropylene

    DEFF Research Database (Denmark)

    Gamstedt, E.K.; Berglund, L.A.; Peijs, T.

    1999-01-01

    Polypropylene (PP) and polypropylene modified with maleic anhydride (MA-PP) reinforced by continuous longitudinal glass fibres have been investigated. The most prominent effect of the modification with maleic anhydride in the composite is a stronger fibre/matrix interface. The effects of...... about one decade for the composite with the stronger interface by use of the maleic-anhydride grafted polypropylene matrix. During the fatigue testing, the microscopic mechanisms were monitored intermittently by a surface replication technique. From microscopic observations, it could be concluded that...

  6. Prosthetic abdominal wall hernia repair in emergency surgery: from polypropylene to biological meshes

    Directory of Open Access Journals (Sweden)

    Campanelli G

    2008-12-01

    Full Text Available Abstract The use of nonabsorbable prosthetic materials such as polypropylene, polyester, and ePTFE, have expanded and are now widely used in reparative surgery for abdominal wall hernias. There are still difficulties to find correct indication for prosthetic implant in emergency hernia surgery: as a matter of fact there is still a great debate if to use non-absorbable prostheses in potentially or truly infected operating fields [e.g. after intestinal resections]. All these problems can be avoided with the use of absorbable prosthetic materials such as those composed of lactic acid polymers or lactic and glycolic acid copolymers: however, the use of these absorbable prosthesis exposes the patient to a rapid and inevitable hernia recurrence. It is important to remember that prosthetic repair has been proven to have a significant less risk of recurrence than repair with direct sutures. Recently, new "biologic" prosthetic materials have been developed and proposed for the clinical use in infected fields. These materials can be called "remodeling" for the way by which they are replaced after their placement within the patient. The "remodeling" process is made possible through a process of incorporation, where a reproduction of a site-specific tissue similar to the original host tissue is created.

  7. POLYPROPYLENE/CLAY NANOCOMPOSITES: SYNTHESIS AND CHARACTERIZATION

    Directory of Open Access Journals (Sweden)

    MÓNICA A PÉREZ

    2010-12-01

    Full Text Available Polypropylene nanocomposites were synthesized by using the method of mixing in the molten state. Nanocomposites were obtained in twin-screw co-rotating extruders and the nanocomposites were prepared with percentage of nanoclay (C2 from 5 wt-%, with and without compatibilizer agent (PP-g-MA. The thermal (DSC, TGA, morphology (XRD, TEM, and dynamical mechanical (DMA properties of the nanocomposites were characterized. All nanocomposites prepared are in intercalated state as corroborated by XRD and TEM. The Tm and Xc were not affected by the presence of clay, PP-g-MA, or processing support. The incorporation of clay and compatibilizer agent increases the thermal stability and heat deflection temperature (HDT.

  8. Anisotropic thermal conductivity in sheared polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Shao Cong; Tanner, Roger I. [The University of Sydney, Rheology Research Group, School of Aerospace, Mechanical and Mechatronic Engineering, Sydney, NSW (Australia)

    2006-01-01

    We discuss the anisotropy of the thermal conductivity tensor in polymer flow in this paper. Isotactic polypropylene (iPP) specimens were deformed by injection moulding at high shear rates and by steady shear at low shear rates, and were then quenched. The thermal conductivities parallel and perpendicular to the shear direction were measured using modulated differential scanning calorimetry (MDSC) in accordance with the ASTM E1952-01. The measured results showed that the thermal conductivity of the sheared polymer was anisotropic with an increase in the shear direction. The thermal conductivity can be regarded as varying either with the strain or the stress, as suggested by Van den Brule (1989). In addition to the Van den Brule mechanism, crystallization during flow also changes the thermal conductivity and this effect may often be dominant. Suggestions for procedures in processing computations, based on both effects, are given. (orig.)

  9. POLYPROPYLENE/CLAY NANOCOMPOSITES: SYNTHESIS AND CHARACTERIZATION

    Scientific Electronic Library Online (English)

    MÓNICA A, PÉREZ; BERNABÉ L, RIVAS; SADDYS M, RODRÍGUEZ; ÁLVARO, MALDONADO; CAROLA, VENEGAS.

    2010-12-01

    Full Text Available Polypropylene nanocomposites were synthesized by using the method of mixing in the molten state. Nanocomposites were obtained in twin-screw co-rotating extruders and the nanocomposites were prepared with percentage of nanoclay (C2) from 5 wt-%, with and without compatibilizer agent (PP-g-MA). The th [...] ermal (DSC, TGA), morphology (XRD, TEM), and dynamical mechanical (DMA) properties of the nanocomposites were characterized. All nanocomposites prepared are in intercalated state as corroborated by XRD and TEM. The Tm and Xc were not affected by the presence of clay, PP-g-MA, or processing support. The incorporation of clay and compatibilizer agent increases the thermal stability and heat deflection temperature (HDT).

  10. Mechanical Properties of Nanofilled Polypropylene Composites

    Directory of Open Access Journals (Sweden)

    Cristina-Elisabeta PELIN

    2015-06-01

    Full Text Available The paper presents a study concerning mechanical performance of thermoplastic nanocomposites based on isotactic polypropylene matrix, nanofilled with montmorillonite modified with quaternary ammonium salt and carboxyl functionalized carbon nanotubes, respectively, added in the same concentration relative to the matrix. The nanofilled and single polymer materials were obtained by simple melt compounding through extrusion process followed by injection molding into specific shape specimens for mechanical testing of the samples. Mechanical properties were evaluated by tensile and 3 point bending tests. In terms of modulus of elasticity, the results showed overall positive effects concerning the effect of nanofiller addition to the thermoplastic polymer. The fracture cross section of the tested specimens was characterized by FT-IR spectroscopy and SEM microscopy.

  11. Ionizing radiation effect on Brazilian polypropylene

    International Nuclear Information System (INIS)

    Polypropylene is a thermoplastic polymer, partially crystalline that can be making in three conformations: atactic, sindiotactic and isotatic. Isotatic polypropylene (PP) that has practical interest, it is employed for manufacture of medical devices, which must be sterilized before using. PP was irradiated with gamma rays from 60 C Co source, whose dose rate was 1.1 and 4.5 kGy/h and the dose range was 0-255 kGy. The irradiations were realized in the presence of air at room temperature. The radiation effects on PP were investigated by IR spectroscopy, electron paramagnetic resonance, viscosimetric average molecular weight (Mw), at 1350 C in decaline and tensile strength at yield (TSy). The PP undergoes radiolytical oxidation up to 100 kGy. The observed radicals at room temperature are: polyenil and peroxyl in the greater concentration. The scission predominates at doses until 100 kGy and above 150 kGy predominates the crosslinking, indicating that the radiation promotes scissions of C - C H3 bonds with such frequency that the sterical hindered gives up existing. At sterilization doses the increase of dose rate promotes the crosslinking. None dose rate effects in Mw was observed at 100 kGy doses. Within 4 days after irradiation end the scissions of backbone remain occurring as consequence of macro radicals oxidation which migrate from the crystalline regions to the amorphous regions. This post-irradiation effect was also observed in macroscopic properties. TSy decays at 25% until about 2 months after the irradiation end. After this time the TSy increases and one year after the irradiation end reaches nearly initial value. The slow process of scission and crosslinking or polymeric backbones entanglement happens. The national PP is protected against radiolytic oxidation adequately during the radiosterilization but is not against backbone scission. After the radiosterilization the PP has a maximum fall of TSy of 25% which is restored after about one year. (author). 50 refs., 36 figs., 12 tabs

  12. Total laparoscopic hysterectomy via suture and ligation technique

    Science.gov (United States)

    Kang, Hye Won; Lee, Ji Won; Kim, Ho Yeon; Kim, Bo Wook

    2016-01-01

    Objective The term 'total laparoscopic hysterectomy (TLH) with classical suture method' refers to a surgical procedure performed using only sutures and ligations with intracorporeal or extracorporeal ties, without using any laser or electronic cauterization devices during laparoscopic surgery as in total abdominal hysterectomy. However, the method is not as widely used as electric coagulation equipment for TLH because further advances in technology and surgical technique are required and operative time can take longer. In the current study, we evaluated the benefits of the classical suture method for TLH. Methods This study retrospectively reviewed patients who received TLH using the classical suture method from August 2005 to April 2014. The patients' baseline characteristics were analyzed, including age, parity, cause of operation, medical and surgical history. Surgical outcomes analyzed included the weight of the uterus, operative time, complications, changes in hemoglobin level, blood transfusion requirements, and postoperative hospital stay. Results Of 746 patients who underwent TLH with the classical suture method, mean operation time was 96.9 minutes. Mean average decline in hemoglobin was 1.6 g/dL and transfusion rate was 6.2%. Urinary tract injuries were reported in 8 patients. Urinary tract injuries comprised 6 cases of bladder injury and 3 cases of ureter injury. There were no cases of vaginal stump infection, hematoma, bowel injury or abdominal wound complication. All cases involving complications occurred before 2010. Conclusion The classical suture method for TLH presents tolerable levels of complications and blood loss. Advanced surgical skill is expected to decrease operation time and complications.

  13. EVALUATION OF ADJUSTABLE SUTURE TECHNIQUE IN OUTCOME OF PTOSIS SURGERY

    Directory of Open Access Journals (Sweden)

    Nagaraju

    2015-10-01

    Full Text Available AIM: To evaluate the outcome of adjustable suture technique in ptosis surgery. INTRODUCTION : Surgical management of blepharoptosis is indicated in multiple situations and the post - operative outcomes can be as variable as the indications for surgery. Adjustable suture techniques in ptosis repair have been introduced and variable efficacies have been reported. MATERIALS AND METHODS: A retrospective case review of medical records from June 2010 to May 2011 (12 months of 5 eyes of 5 consecutive patients operated by a single surgeon at a Tertiary Eye care center in South India were reviewed. The clinical profile of patients included was r ecorded and results of adjustable suture technique described by Borman and collegues for these patients was reported. RESULTS: 5 eyes of 5 patients underwent adjustable suture ptosis repair in the study duration. 4 patients with moderate and 1 with severe ptosis, all having good levator function were diagnosed to have c ongenital ptosis in 3 cases and a cquired involutional ptosis in 2 cases. All 5 cases had a satisfactory outcome at day 4 post - operative after adjustment of lid height in the out - patient clini c. 1 patient with acquired involutional ptosis, identified with levator dehiscence intra - operatively had overcorrection at 6 months warranting re - surgery while the other 4 patients had satisfactory cosmetic lid height and functional outcome at 6 months fol low up after the adjustable suture technique for ptosis repair. CONCLUSION: Use of adjustable sutures in ptosis surgery can eliminate the intraoperative lid factors that can lead to unpredictable results. The technique described is easy to adapt and perfor m and can give repeatable and well acceptable results in the properly selected cases

  14. Interrupted or continuous-intradermal suturing? Statistical analysis of postoperative scars

    Directory of Open Access Journals (Sweden)

    Elif Sar?

    2014-12-01

    Full Text Available Background and Design: Postoperative scar development is an important problem for patients treated in plastic surgery clinics. Most patients think that continuous intradermal suturing is superior to interrupted suturing because they assume that it creates less scarring. We evaluated scars that form following intradermal and interrupted suturing. This article presents our controlled study that objectively compared the scars on patients' faces using a wound evaluation scale. Materials and Methods: Thirty-five patients, who had undergone operations on the bilateral cheeks, were included in this study. Thirty patients were female; five patients were male. Their mean age was 40.05 years. The average scar evaluation time after surgery was 9.05 months. Elliptical excisions were made on the lesions under local anesthesia. The incisions on the right cheeks were sutured with 6/0 monofilament nonabsorbable sutures using the continuous intradermal suturing technique. The left cheek incisions were sutured with same sutures using the interrupted suturing method. Results: The patients were evaluated 7–11 months after operation (mean: 9.05 months using the Stony Brook Scar Evaluation Scale. A Related Samples T-test was used for statistical evaluation of the differences between the suturing techniques. No significant differences were noted in scar formation between the two suturing methods (p>0.05. Conclusion: We found no differences in scar formation between the two frequently used suturing techniques studied here. We believe that the suturing technique is a less important determinant of scar formation than are other factors.

  15. Familial idiopathic hypertrophic osteoarthropathy and cranial suture defects in children

    International Nuclear Information System (INIS)

    Three children with idiopathic hypertrophic osteoarthropathy and cranial suture defects are reported. The syndrome was recognized after birth and in the two oldest siblings, the cranial defects and subperiosteal bone formation resolved almost completely by age 4 and 6 years. The joint swelling and clubbing persisted and mild bone reabsorption of the distal phalanges became apparent at an older age. Two siblings and both parents had normal bone X-rays and no clubbing. This study confirms the association of cranial sutural defects and familial idopathic hypertrophic osteoarthropathy. (orig.)

  16. Later reproductive health after B-Lynch sutures

    DEFF Research Database (Denmark)

    Fuglsang, Jens

    2014-01-01

    OBJECTIVE: To evaluate the reproductive prognosis after having a B-Lynch suture placed previously. DESIGN: Follow-up study based on patients' records. SETTING: University hospital setting (level three; 4,800 deliveries per year). PATIENT(S): All patients registered to have had a B-Lynch suture placed from 2002 to 2012. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Future pregnancies. RESULT(S): Forty-four B-Lynch procedures were identified in 43 women. Twenty-six were primiparas at the time of...

  17. Thermal conductivity of polypropylene filled with inorganic particles

    Energy Technology Data Exchange (ETDEWEB)

    Muratov, D.S., E-mail: muratov@misis.ru; Kuznetsov, D.V.; Il’inykh, I.A.; Mazov, I.N.; Stepashkin, A.A.; Tcherdyntsev, V.V.

    2014-02-15

    Highlights: ? Better thermal conductivity in PP samples filled with h-BN. ? Filler particle size affect composite thermal conductivity. ? Thermal conductivity was measured for different filler amount. -- Abstract: Boron and aluminium nitride, as well as carbon materials, were used as fillers for polypropylene to increase its thermal conductivity. Better thermal conductivity was observed for samples filled with nanosized BN. All composites show thermal stability up to 250 °C. Filling of polypropylene was shown to affect crystallinity degree, adding of BN and carbon nanotubes results in the increase in crystallinity of polypropylene. It was observed that BN forms chemical bonds with polymer matrix, whereas no evidence of such bonds was found in case of polypropylene filled with AlN particles.

  18. Effect of ultraviolet radiation (300-400 nanometers) on polypropylene

    International Nuclear Information System (INIS)

    Polypropylene discs and shavings were exposed to simulated ambient ultraviolet (UV) radiation (lambda 300-400 nm) for a period equivalent to at least two years of wear within the eye, assuming the eye to be exposed to ambient UV radiation for four hours per day at 1 mW/cm2. The polypropylene and the incubation media were measured by several forms of optical spectroscopy, and there was no photochemical change in either. Where polypropylene discs were exposed to a very high level of UV radiation (greater than 500 W/cm2), they became brittle and discolored within five to ten days. This level of exposure, however, was equivalent to a total of over 20 million joules/cm2, which is at least one million times levels for expected ambient UV exposure to polypropylene within the eye

  19. Radiation cross-linking of montmorillonite/polypropylene composite

    International Nuclear Information System (INIS)

    Polypropylene/montmorillonite composite was prepared via melt compounding process. The dispersion of montmorillonite in the composite was analyzed by XRD (X-ray diffraction) and TEM (Transmission electron microscope). Electronic radiation was applied to make the composite radiation cross-linked in air. The effect of cross-linking agent and montmorillonite on the properties of polypropylene cross-linking was studied. The results indicated that cross-linking did not take place in absence of cross-linking agent, while in presence of both cross-linking agent and montmorillonite polypropylene cross-linking occurred in certain absorbed dose range. The cross-linked polypropylene/montmorillonite composite exhibited improved mechanical properties. (authors)

  20. Thermal conductivity of polypropylene filled with inorganic particles

    International Nuclear Information System (INIS)

    Highlights: ► Better thermal conductivity in PP samples filled with h-BN. ► Filler particle size affect composite thermal conductivity. ► Thermal conductivity was measured for different filler amount. -- Abstract: Boron and aluminium nitride, as well as carbon materials, were used as fillers for polypropylene to increase its thermal conductivity. Better thermal conductivity was observed for samples filled with nanosized BN. All composites show thermal stability up to 250 °C. Filling of polypropylene was shown to affect crystallinity degree, adding of BN and carbon nanotubes results in the increase in crystallinity of polypropylene. It was observed that BN forms chemical bonds with polymer matrix, whereas no evidence of such bonds was found in case of polypropylene filled with AlN particles

  1. Preparation of Polypropylene/Montmorillonite Nanocomposites Using Ionizing Radiation

    International Nuclear Information System (INIS)

    Polymer/clay nanocomposites are new generation materials that bring significant changes in mechanical, thermal and permeation properties of base polymers by low clay loading. In this study, polypropylene/montmorillonite nanocomposites were prepared by melt intercalation method by using batch type mixer. Two polypropylene samples with different melt flow indexes are used as the matrix, maleic anhydride grafted polypropylene (PP-g-MAH), and polypropylene granules oxidized by radiation/ozone are used as compatibilizer and unmodified clay (Na+ montmorillonite, MMT) as the filler. Aim of this study is to examine the effect of different compatibilizers in the mechanical properties of polypropylene composite. Firstly, PP/clay samples were prepared and the effect of clay was examined, then 5, 10, 20kGy oxidized/degraded polypropylenes were used as compatibilizer and, 10 kGy was determined to be the most suitable irradiation dose for the best compatibilizing effect. Polypropylene granules were ozonated until they contained carbonyl groups equivalent to 10kGy oxidized PP, which was checked by FTIR-ATR spectroscopy. UV-visible reflectance measurements were also made on film samples and no significant changes were observed in visible region. Nano structures of some nanocomposites were characterized by PALS (Positron Annihilation Lifetime Spectroscopy) where it was observed that the addition of clay decreased the number of free volume holes and free volume hole radia. The dispersion state of MMT within polymer matrix was analyzed by XRD (X-ray diffraction). Tensile tests were made and the effect of the addition of clay and compatibilizers investigated. At low melt flow index PP, 1% MMT of PP/10kGyPP/MMT nanocomposite showed an increase in E-modulus 26% and in tensile strength 8% as compared to those of pristine PP. In conclusion radiation degraded (chain scissioned and oxidized) PP has been found to show very good compatibilizing effect for the natural montmorillonite/polypropylene composites. (author)

  2. Rheometric research of polypropylene Licocene PP2602 melts

    OpenAIRE

    V.V. Romanuke; I.A. Mandzyuk

    2011-01-01

    Purpose: To comprehend and ascertain reasons of the transition into the non-Newtonian viscosity zone for the melted polypropylene material, depending upon the number of recycling series.Design/methodology/approach: There were carried researches on rheological features of the primary material of the melted polypropylene Licocene PP2602, subjected to be processed repeatedly in as many series as needed, using the Brookfield viscometer CAP2000+ within the temperature range 130-200ºC and the shear...

  3. Graft copolymerization of acrylonitrile onto polypropylene membrane by preirradiation

    International Nuclear Information System (INIS)

    A porous, graft copolymer and amidoxime group containing membrane were prepared by radiation graft copolymerization of acrylonitrile onto porous polypropylene. In order to calculate the grafting and amidoxime ratios of porous polypropylene-acrylonitrile graft copolymer. We have done CHN elemental analysis. It is obtained the result that grafting rate is increased to linear and value was about 75 percent at 20 Mrad dose rate. (Author)

  4. Application of gas chromatography to the investigations on polypropylene radiolysis

    International Nuclear Information System (INIS)

    Refinement of the gas chromatography (GC) instrumental approach permitted not only improvement of investigation in basic research, but also development of a new kind of polypropylene blends, more suitable for the production of medical devices and radiation sterilization. It has been shown, that using the GC method not only methane and carbon dioxide can be measured, but also the consumption of oxygen which reacts with free radicals on the polypropylene chain

  5. Fatigue mechanisms in unidirectional glass-fibre-reinforced polypropylene

    DEFF Research Database (Denmark)

    Gamstedt, E.K.; Berglund, L.A.; Peijs, T.

    1999-01-01

    Polypropylene (PP) and polypropylene modified with maleic anhydride (MA-PP) reinforced by continuous longitudinal glass fibres have been investigated. The most prominent effect of the modification with maleic anhydride in the composite is a stronger fibre/matrix interface. The effects of interfacial strength on fatigue performance and on the underlying micromechanisms have been studied for these composite systems. Tension-tension fatigue tests (R = 0.1) were carried out on 0 degrees glass-fibre/...

  6. Radiation resistant modified polypropylene; Polipropylen modyfikowany odporny radiacyjnie

    Energy Technology Data Exchange (ETDEWEB)

    Bojarski, J.; Zimek, Z. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1997-10-01

    Radiation technology for production of radiation resistant polypropylene for medical use has been presented. The method consists in radiation induced copolymerization of polypropylene with ethylene and addition of small amount of copolymer of polyethylene and vinyl acetate. The material of proposed composition has a very good mechanical properties and elevated radiation resistivity decided on possibility of radiosterilization of products made of this material and designed for medical use. 3 figs, 3 tabs.

  7. Study on the Dynamic Performance of Polypropylene Fiber Reinforced Concrete

    OpenAIRE

    Zhang Ying; Zheng Chunhang; Wu Rujun; Chen Xi; Guoping Jiang

    2013-01-01

    The dynamic performance of polypropylene fiber reinforced concrete is studied with the SHPB experiment. The relationship of the strain-stress curves are all obtained in the experiment. The crack characteristics of polypropylene reinforced concrete and plain concrete are also investigated. Analyzed the relation between the character on the crack surface of concrete and material properties and the impact pressure. Also the multi-fractal characteristics are given on the crack surface of concrete...

  8. The fire resistance of concrete with polypropylene fibers

    OpenAIRE

    Corpas F.A.; González B; Gómez L.; Rosa F.; Figueroa J.M

    2013-01-01

    This paper presents the results and conclusions of an experimental study characterization performed on the polypropylene fibers for use in concretes (NPC, Normal Performance Concrete) to produce an improvement in the durability against exposure to high temperatures. It was used only one type of polypropylene fiber with two different lengths, 6 mm and 12 mm, to evaluate the effect of the length.

  9. Investigation of Mechanical Properties of Rice Straw Fibre Polypropylene Composites

    OpenAIRE

    K Sudhakar,; Ch. Srinivas

    2014-01-01

    The main objective of present work is to investigate the mechanical properties of rice straw fibre reinforced polypropylene composites at different weight fractions (0%, 5%, 10%, 15%, 20% and 25%) of rice straw fibre. Rice straw fibre reinforced polypropylene composites were manufactured according to ASTM standards using injection moulding technique. The developed composites were then tested for their tensile, bending and impact properties. The standard test methods ASTM-D638M...

  10. Polypropylene/graphite nanocomposites by in situ polymerization

    International Nuclear Information System (INIS)

    This work presents the synthesis of nanocomposites of polypropylene/graphite by in situ polymerization using metallocene catalyst and graphene nanosheets. Initially was analyzed which of the metallocene catalysts rac-Et(Ind)2ZrCl2 or rac-Me2Si(Ind)2ZrCl2 produces polypropylene with mechanical properties more relevant. Then it were performed the in situ polymerization reactions to obtain the nanocomposites. The polymeric materials were characterized by XRD, DSC, GPC and DMTA. (author)

  11. Absence of Endochondral Ossification and Craniosynostosis in Posterior Frontal Cranial Sutures of Axin2?/? Mice

    OpenAIRE

    Behr, Björn; Longaker, Michael T.; Quarto, Natalina

    2013-01-01

    During the first month of life, the murine posterior-frontal suture (PF) of the cranial vault closes through endochondral ossification, while other sutures remain patent. These processes are tightly regulated by canonical Wnt signaling. Low levels of active canonical Wnt signaling enable endochondral ossification and therefore PF-suture closure, whereas constitutive activation of canonical Wnt causes PF-suture patency. We therefore sought to test this concept with a knockout mouse model. PF-s...

  12. Comparison of the cheese-wiring effects among three sutures used in rotator cuff repair

    Directory of Open Access Journals (Sweden)

    Mark Lambrechts

    2014-01-01

    Full Text Available Purpose: The goal of this study was to compare the cheese-wiring effects of three sutures with different coefficients of friction. Materials and methods: Sixteen human cadaveric shoulders were dissected to expose the distal supraspinatus and infraspinatus muscle tendons. Three sutures were stitched through the tendons: #2 Orthocord™ suture (reference #223114, DePuy Mitek, Inc., Raynham, MA, #2 ETHIBONDFNx01 EXCEL Suture, and #2 FiberWire® suture (FiberWire® , Arthrex, Naples, FL. The sutures were pulled by cyclic axial forces from 10 to 70 N at 1 Hz for 1000 cycles through a MTS machine. The cut-through distance on the tendon was measured with a digital caliper. Results: The cut-through distance in the supraspinatus tendons (mean ± standard deviation, n = 12 were 2.9 ± 0.6 mm for #2 Orthocord™ suture, 3.2 ± 1.2 mm for #2 ETHIBONDFNx01 suture, and 4.2 ± 1.7 mm for #2 FiberWire® suture. The differences were statistically significant analyzing with analysis of variance (P = 0.047 and two-tailed Student?s t-test, which showed significance between Orthocord™ and FiberWire® sutures (P = 0.026, but not significant between Orthocord™ and ETHIBONDFNx01 sutures (P = 0.607 or between ETHIBONDFNx01 and FiberWire® sutures (P = 0.103. Conclusion: The cheese-wiring effect is less in the Orthocord™ suture than in the FiberWire® suture in human cadaveric supraspinatus tendons. Clinical Relevance: Identification of sutures that cause high levels of tendon cheese-wiring after rotator cuff repair can lead to better suture selection.

  13. Comparison between Silk Sutures and Cyanoacrylate Adhesive in Human Mucosa- A Clinical and Histological Study

    OpenAIRE

    Kumar, M Suresh; Natta, Sreelakshmi; Shankar, Gowri; Reddy, S Hari Krishna; Visalakshi, D; Seshiah, G V

    2013-01-01

    Background: Closing the surgical incision is an important step in the surgical procedures, the success of surgery is sometimes compromised by the defective suturing techniques or improper suturing materials, black silk sutures are more or less most often used materials in the day today surgical procedures, but these suture materials demand more time and effort from the surgeon and there is a need to substitute these materials with more user friendly and more successful wound closing materials...

  14. Suture supported P C IOL in a homocystinuric child.

    Directory of Open Access Journals (Sweden)

    Bhatti S

    1996-01-01

    Full Text Available A homocystinuric child presented with a secondary pupillary block glaucoma due to anteriorly subluxated lens. After removal of the subluxated lens, a suture supported posterior chamber IOL was implanted. Postoperative complication of cerebral venous thrombosis following general anaesthesia was managed with high doses of pyridoxine special diet and drugs.

  15. Healing of the suture line in the irradiated small intestine

    International Nuclear Information System (INIS)

    With the help of data from literature the author goes more deeply into the aetiology, treatment and possible prevention of lesions of the small intestine related to preceding irradiation. In a clinical retrospective study at twenty patients who, after irradiation of the abdominal and pelvic areas, have been submitted to abdominal surgery, the relation is studied between predistion factors for gastrointestinal complications after irradiation, the surgeries applied in case of small-intestine problems and postoperative complications. The third part of the thesis covers an experimental part in which the healing process of suture line in the terminal ileum has been studied after resection and reanastomosis in previously irradiated bowel of the rat. It was investigated whether differences occurred in the healing process of suture line after various periods - 4, 10 and 40 weeks, after irradiation. Also comparison took place with a control group which underwent a similar procedure with the exception of the radiation treatment, which was simulated in this group. In a second experiment it was investigated if the healing process of suture line depends on the type of anastomosis. An end-to-end anastomosis was chosen versus side-to-side anastomosis. Also in this experiment an irradiated group was compared with a control group. Furthermore a method was developed for performing micro-angiographies of the rat intestine in order to demonstrate obliteration of blood vessels in irradiated intestine and to assess neovascularization in the intestinal wall at the suture line. (author). 84 refs.; 18 figs.; 27 tabs

  16. Obliteration of serrated sutures of a human skull (review

    Directory of Open Access Journals (Sweden)

    Zaichenko A.A.

    2011-09-01

    Full Text Available The review presents information on obliteration of serrated sutures of a human skull. It considers the age-specific variability and sexual dimorphism. The causes of craniostenosis and dependence of cranial form on degree and type of craniostenosis are described

  17. 21 CFR 878.5030 - Natural nonabsorbable silk surgical suture.

    Science.gov (United States)

    2010-04-01

    ... SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.5030... color additive. (b) Classification. Class II (special controls). The special control for this device is FDA's “Class II Special Controls Guidance Document: Surgical Sutures; Guidance for Industry and...

  18. 21 CFR 878.5020 - Nonabsorbable polyamide surgical suture.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.5020 Nonabsorbable... for this device is FDA's “Class II Special Controls Guidance Document: Surgical Sutures; Guidance for Industry and FDA.” See § 878.1(e) for the availability of this guidance document....

  19. Cytology of suture granuloma in a recurrent thyroid nodule

    Directory of Open Access Journals (Sweden)

    G. J. Vani Padmaja

    2014-02-01

    Full Text Available Foreign body giant cell (FBGC reaction leading to suture granu-loma is known to occur in response to suture material used during surgery. It occurs most commonly in the gastrointestinal tract (GIT. It is rare to find a suture granuloma in the thyroid. After ex-tensive search of the literature, it was found that such a lesion has been reported so far on guided aspirates, but not on fine needle aspiration cytology (FNAC alone. The cytomorphology on FNAC is important to clinch the diagnosis and avoid unnecessary surgery as it can mimic a malignant thyroid nodule, multinodular goiter or a metastatic lymph node. This is the first case report of such a lesion to date. We report a 54 year old male with a recurrent firm thyroid nodule on the right side of the neck, for whom FNAC was done. It was reported as a suture granuloma on cytology. Hence the case was managed conservatively since malignancy was ruled out.

  20. Radiographic changes in non-operated isolated sagittal suture synostosis

    International Nuclear Information System (INIS)

    Purpose: To characterize the spontaneous clinical course of isolated sagittal synostosis based on planar skull radiography. Materials and Methods: In this retrospective analysis we evaluated a total of 155 radiographs of 55 children 2 weeks to 9 years old. The sagittal, coronal and lambdoid sutures were evaluated on the basis of pairs of ap and lateral radiographs. The sutures were examined with respect to their boundary, activity, and conspicuity to be visualized (based on a 3-grade score system). Six selected points on the skull X-ray defined eight measured distances, three angles, and a width-length index. To document changes over time, the measurements were correlated to normal values. In addition, a correlation between suture activity and selected parameters was evaluated. Results: The sagittal suture could be continuously or partially depicted in more then half of all radiographs taken during the first year of life. The measured distances and angles were concordant with results from the literature. With increasing age, the width-length index deviated from standard values while other parameters approximated the norm. (orig.)

  1. Neonatal subperiosteal cephalohematoma crossing a synostosed sagittal suture

    Energy Technology Data Exchange (ETDEWEB)

    Currarino, Guido [Texas Scottish Rite Hospital, Department of Radiology, Dallas, TX (United States)

    2007-12-15

    A newborn boy, born at term by a spontaneous delivery, presented in the first day of life with a soft-tissue mass across a synostosed segment of the sagittal suture. In the following week the mass became better defined and showed peripheral calcifications consistent with a calcified subperiosteal hematoma. (orig.)

  2. The fourth suture in MACS facelifting – adressing the neck

    Directory of Open Access Journals (Sweden)

    Kaye, Kai O.

    2014-12-01

    Full Text Available Objective: The MACS facelift alone shows poor results on the medial neck in cases of pronounced, rigid platysmabands (McKinney III–IV°. The original MACS (“Minimal Access Cranial Suspension” facelift delirs excellent results on the midface and leads to sustainably improved outcome on the neck by adding a fourth suture on the platysma. McKinney type I–II platysmabands can be treated only by lateral approach of the ‘fourth suture’, type III–IV should be treated with closed platysma myotomy before.Methods: Between October 2007 and November 2013 a number of 219 patients were treated with the MACS facelift technique accomplished by a fourth suture on the platysma and liposuction or optional lipectomy on the neck. On 47 patients closed transcutaneous platysma myotomy was performed.Results: Surgery time lasted on average 2.5 hours and was performed under sedation with local anesthesia in 85%. Recovery time ranged between 14 to 16 days until the patients were back to work. Due to their health status 54% of our patients had an inpatient arrangement for one night and 46% an outpatient arrangement.Conclusion: The modification of the MACS lift with the ‘fourth suture’ on the platysma keeps the benefits of the original technique but improves the aesthetic outcome on the neck.

  3. Penile torsion correction by diagonal corporal plication sutures

    Scientific Electronic Library Online (English)

    Brent W., Snow.

    2009-02-01

    Full Text Available Penile torsion is commonly encountered. It can be caused by skin and dartos adherence or Buck’s fascia attachments. The authors suggest a new surgical approach to solve both problems. If Buck’s fascia involvement is demonstrated by artificial erection then a new diagonal corporal plication suture is [...] described to effectively solve this problem.

  4. Effects of Citalopram on Sutural and Calvarial Cell Processes

    Science.gov (United States)

    Durham, Emily; Jen, Serena; Wang, Lin; Nasworthy, Joseph; Elsalanty, Mohammed; Weinberg, Seth; Yu, Jack; Cray, James

    2015-01-01

    The use of selective serotonin reuptake inhibitors (SSRIs) for the treatment of depression during pregnancy is suggested to increase the incidence of craniofacial abnormalities including craniosynostosis. Little is known about this mechanism, however based on previous data we propose a mechanism that affects cell cycle. Excessive proliferation, and reduction in apoptosis may lead to hyperplasia within the suture that may allow for differentiation, bony infiltration, and fusion. Here we utilized in vivo and in vitro analysis to investigate this proposed phenomenon. For in vivo analysis we used C57BL–6 wild-type breeders treated with a clinical dose of citalopram during the third trimester of pregnancy to produce litters exposed to the SSRI citalopram in utero. At post-natal day 15 sutures were harvested from resulting pups and subjected to histomorphometric analysis for proliferation (PCNA) and apoptosis (TUNEL). For in vitro studies, we used mouse calvarial pre-osteoblast cells (MC3T3-E1) to assess proliferation (MTS), apoptosis (Caspase 3/7-activity), and gene expression after exposure to titrated doses of citalopram. In vivo analysis for PCNA suggested segregation of effect by location, with the sagittal suture, showing a statistically significant increase in proliferative response. The coronal suture was not similarly affected, however there was a decrease in apoptotic activity at the dural edge as compared to the periosteal edge. No differences in apoptosis by suture or area due to SSRI exposure were observed. In vitro results suggest citalopram exposure increased proliferation and proliferative gene expression, and decreased apoptosis of the MC3T3-E1 cells. Decreased apoptosis was not confirmed in vivo however, an increase in proliferation without a concomitant increase in apoptosis is still defined as hyperplasia. Thus prenatal SSRI exposure may exert a negative effect on post-natal growth through a hyperplasia effect at the cranial growth sites perhaps leading to clinically significant craniofacial abnormalities. PMID:26431045

  5. Study on grafting acrylonitrile and acrylic acid onto polypropylene nonwoven fabrics polypropylene nonwoven fabrics

    International Nuclear Information System (INIS)

    In this paper, co-grafting reaction of acrylonitrile and acrylic acid onto pre-irradiated polypropylene nonwoven fabrics in air medium has been studied. The degree of grafting has been determined as a function of irradiation dose, reaction temperature, reaction time, monomer concentration, ratio of monomers and the concentration of Mohr's. The results showed that the best condition of grafting reaction was reaction temperature 75 degree C, reaction time 4 h, monomer concentration 50%. Structure of the grafted polymer have been studied by FT-IR. (authors)

  6. Post-irradiation degradation of polypropylene

    International Nuclear Information System (INIS)

    The mechanical changes (elongation at break, tensile strength, modulus of elasticity) and electrical changes (volume and surface resistivity, tg?, ?, breakdown voltage) of isotactic polypropylene (PP) due to ?-radiation. Ageing of PP was achieved in air by using a 137Cs ?-source with 400 Ci activity; the dose rate was of 8 x 104 rad/h, and the integrated doses ranged from 2 to 160 Mrad. Severe deterioration of mechanical properties was observed. The changes of electrical properties were not as significant as those of mechanical characteristics. These variations are caused by the increase in density of crosslinking chain-scission and by oxidative processes. The rate of extent of degradation has been evaluated by the growth of the hyydroxy and carbonyl bands in the IR spectrum. By using FTIR mapping, it was also investigated the degradation of PP which had been irradiated in air 15 years ago. It was determined the contour lines of FTIR absorption bands of carbonyl groups at different regions of the cross-section of an irradiated sample. Dust particles of irradiated brittle PP were also studied. The FTIR showed that the carbonyl band is broad, indicating a mixtures of many different functional groups (ester, acid, ketone, lactones). It was determined also the gel content at different irradiation doses. (author) 12 refs.; 4 figs.; 3 tabs

  7. Polypropylene matrix composites reinforced with coconut fibers

    Directory of Open Access Journals (Sweden)

    Maria Virginia Gelfuso

    2011-09-01

    Full Text Available Polypropylene matrix composites reinforced with treated coconut fibers were produced. Fibers chemically treated (alkalization-CCUV samples or mechanically treated (ultrasonic shockwave-CMUV samples were dried using UV radiation. The goal was to combine low cost and eco-friendly treatments to improve fiber-matrix adhesion. Composite samples containing up to 20 vol. (% of untreated and treated coconut fibers were taken from boxes fabricated by injection molding. Water absorption and mechanical properties were investigated according to ASTM D570-98 and ASTM D638-03, respectively. Electrical characterizations were carried out to identify applications of these composites in the electrical sector. NBR 10296-Electrical Tracking Standard (specific to industry applications and conductivity measurements were obtained applying 5 kV DC to the samples. CMUV samples containing 5 vol. (% fiber presented superior tensile strength values (?~28 MPa compared to the untreated fibers composite (?~22 MPa or alkali treatment (?~24 MPa. However, CMUV composites containing 10 vol. (% fiber presented best results for the electrical tracking test and electrical resistivity (3 × 10(7 ?.m. The results suggest that composites reinforced with mechanically treated coconut fibers are suitable for electrical applications.

  8. Electrical properties of ion irradiated polypropylene films

    Indian Academy of Sciences (India)

    N L Singh; Anita Sharma; V Shrinet; A K Rakshit; D K Avasthi

    2004-06-01

    The effect of high-energy (50 MeV) Li3+ ion beam irradiation on polypropylene (PP) film has been studied in the fluence range 2.4 × 1012-1.5 × 1014 ions/cm2. The a.c. electrical properties of PP films were measured in the frequency range from 0.05–100 kHz, and at temperature range between 30 and 140°C. This study indicates two peaks at 60°C and 120°C with comparatively high magnitudes. There is an exponential increase in conductivity with log of frequency and the effect is significant at higher fluences. The loss factor (tan ) vs frequency plot suggests that PP film based capacitors may be useful below 10 kHz. The capacitance is constant over a wide temperature range up to 130°C. FTIR spectra of the PP films before and after irradiation indicate that intensity of C–H stretching vibration at 2900 cm-1 is modified. The presence of many new peaks with the increase of fluence suggests the formation of alkanes and alkynes which might be responsible for the observed changes in the dielectric and electrical properties of PP films.

  9. Radiation Effects on Polypropylene Carbon Nanofibers

    Science.gov (United States)

    Hamilton, John; Mion, Thomas; Chipara, Alin C.; Ibrahim, Elamin I.; Lozano, Karen; Chipara, Magdalena; Tidrow, Steven C.; Chipara, Mircea

    2010-03-01

    Dispersion of carbon nanostructures within polymeric matrices affects most physical and chemical properties of the polymeric matrix (increased Young modulus, improved thermal stability, faster crystallization rates, higher equilibrium degree of crystallinity, modified glass, melting, and crystallization temperatures, enhanced thermal and electrical conductivity). Such changes have been reported and explained by thorough spectroscopic investigations. Nevertheless, little is known about the radiation stability of such nanocomposites. The research is focused on spectroscopic investigations of radiation-induced modifications in isotactic polypropylene (iPP)-vapor grown nanofiber (VGCNF)composites. VGCNF were dispersed within iPP by extrusion at 180^oC. Composites containing various amounts of VGCNFs ranging from 0 to 20 % wt. were prepared and subjected to gamma irradiation, at room temperature, at various integral doses (10 MGy, 20 MGy, and 30 MGy). Raman spectroscopy, ATR, and WAXS were used to assess the radiation-induced modifications in these nanocomposites. Acknowledgements: This research was supported by the Welch Foundation (Department of Chemistry at UTPA) and by US Army Research Office (AMSRD-ARL-RO-SI: 54498-MS-ISP).

  10. Polypropylene matrix composites reinforced with coconut fibers

    Scientific Electronic Library Online (English)

    Maria Virginia, Gelfuso; Pedro Vieira Gurgel da, Silva; Daniel, Thomazini.

    2011-09-01

    Full Text Available Polypropylene matrix composites reinforced with treated coconut fibers were produced. Fibers chemically treated (alkalization-CCUV samples) or mechanically treated (ultrasonic shockwave-CMUV samples) were dried using UV radiation. The goal was to combine low cost and eco-friendly treatments to impro [...] ve fiber-matrix adhesion. Composite samples containing up to 20 vol. (%) of untreated and treated coconut fibers were taken from boxes fabricated by injection molding. Water absorption and mechanical properties were investigated according to ASTM D570-98 and ASTM D638-03, respectively. Electrical characterizations were carried out to identify applications of these composites in the electrical sector. NBR 10296-Electrical Tracking Standard (specific to industry applications) and conductivity measurements were obtained applying 5 kV DC to the samples. CMUV samples containing 5 vol. (%) fiber presented superior tensile strength values (?~28 MPa) compared to the untreated fibers composite (?~22 MPa) or alkali treatment (?~24 MPa). However, CMUV composites containing 10 vol. (%) fiber presented best results for the electrical tracking test and electrical resistivity (3 × 10(7) ?.m). The results suggest that composites reinforced with mechanically treated coconut fibers are suitable for electrical applications.

  11. Severe Conjunctival Foreign Body Reaction Caused by Polyglactin 910 (Vicryl Suture Material Following Strabismus Surgery

    Directory of Open Access Journals (Sweden)

    Selim Demir

    2014-05-01

    Full Text Available Absorbable suture materials, such as polyglactin 910 (vicryl sutures, can cause a mild foreign body reaction in the eyes that can last up to 45 days. However, these absorbable suture ties can infrequently cause a severe foreign body reaction that can only heal by removal of the sutures. In this report, we present a case of severe conjunctival foreign body reaction in both eyes of a patient and filamentary keratitis in the patient’s left eye caused by the vicryl suture ties after surgery for esotropia. (Turk J Ophthalmol 2014; 44: 252-5

  12. Unravelling the molecular control of calvarial suture fusion in children with craniosynostosis

    Directory of Open Access Journals (Sweden)

    Morris C Phillip

    2007-12-01

    Full Text Available Abstract Background Craniosynostosis, the premature fusion of calvarial sutures, is a common craniofacial abnormality. Causative mutations in more than 10 genes have been identified, involving fibroblast growth factor, transforming growth factor beta, and Eph/ephrin signalling pathways. Mutations affect each human calvarial suture (coronal, sagittal, metopic, and lambdoid differently, suggesting different gene expression patterns exist in each human suture. To better understand the molecular control of human suture morphogenesis we used microarray analysis to identify genes differentially expressed during suture fusion in children with craniosynostosis. Expression differences were also analysed between each unfused suture type, between sutures from syndromic and non-syndromic craniosynostosis patients, and between unfused sutures from individuals with and without craniosynostosis. Results We identified genes with increased expression in unfused sutures compared to fusing/fused sutures that may be pivotal to the maintenance of suture patency or in controlling early osteoblast differentiation (i.e. RBP4, GPC3, C1QTNF3, IL11RA, PTN, POSTN. In addition, we have identified genes with increased expression in fusing/fused suture tissue that we suggest could have a role in premature suture fusion (i.e. WIF1, ANXA3, CYFIP2. Proteins of two of these genes, glypican 3 and retinol binding protein 4, were investigated by immunohistochemistry and localised to the suture mesenchyme and osteogenic fronts of developing human calvaria, respectively, suggesting novel roles for these proteins in the maintenance of suture patency or in controlling early osteoblast differentiation. We show that there is limited difference in whole genome expression between sutures isolated from patients with syndromic and non-syndromic craniosynostosis and confirmed this by quantitative RT-PCR. Furthermore, distinct expression profiles for each unfused suture type were noted, with the metopic suture being most disparate. Finally, although calvarial bones are generally thought to grow without a cartilage precursor, we show histologically and by identification of cartilage-specific gene expression that cartilage may be involved in the morphogenesis of lambdoid and posterior sagittal sutures. Conclusion This study has provided further insight into the complex signalling network which controls human calvarial suture morphogenesis and craniosynostosis. Identified genes are candidates for targeted therapeutic development and to screen for craniosynostosis-causing mutations.

  13. Water Absorption Properties and Morphology of Polypropylene/ Polycarbonate/Polypropylene-graft-Maleic Anhydride Blends

    Directory of Open Access Journals (Sweden)

    P.S.M. Megat-Yusoff

    2013-01-01

    Full Text Available This study investigates the effect of blending polycarbonate (PC into polypropylene (PP matrix polymer on water absorption properties and morphology. The blends, containing 5-35% of polycarbonate and 5% compatibilizer, were compounded using twin - screw extruder and fabricated into standard tests samples using compression molding. The compatibilizer used was polypropylene-graft-maleic anhydride (PP-g-MA. In water absorption test, specimens were immersed in distilled water at 23 and 100°C. In 23°C immersion, PC showed the highest absorption at 0.362 wt.% while PP was the lowest at 0.064 wt.%. The blends demonstrated transitional absorption value between PP and PC. In 100°C immersion, 90/5/5, 80/15/5 and 70/25/5 compositions (PP/PC/PP-g-MA exhibited lower absorption than PP, indicating enhanced long-term degradation resistance in water compared to PP. Microscopy analysis showed that PC existed as fibers, dispersed throughout PP matrix.

  14. Post irradiation degradation of polypropylene radiation durability of polypropylene stabilized with phenolic stabilizer (II)

    International Nuclear Information System (INIS)

    Post irradiation degradation of 60Co gamma irradiated polypropylene stabilized with a phenolic type stabilizer has been followed up to two years after being irradiated. The effectiveness of the stabilizer at various concentrations on the polypropylene samples irradiated up to 150 kGy has been studied and the buildup of carbonyl group in the irradiated samples measured. The obtained results indicated that the oxidative reactions are retarded by addition of stabilizer. The variation of bend strength of the irradiated samples with and without stabilizer was also followed. This property was found to be greatly improved for the stabilized samples irradiated at low doses. However at high doses the effectiveness of the stabilizer declined. In order to correlate these results with the change in the molecular weight of polymer, trends of the change in rheological behaviour such as melt viscosity (μa) and flow behavior parameters (K, n) of both stabilized and unstabilized samples have been investigated. Results showed that at low doses, addition of the stabilizer greatly reduces the extent of chain scission, and therefore, the mechanical properties of the irradiated polymer are retained. (Author)

  15. Synthesis, characterization and properties of carbon nanotubes microspheres from pyrolysis of polypropylene and maleated polypropylene

    International Nuclear Information System (INIS)

    Microspheres assembled from carbon nanotubes (MCNTs), with the diameters ranging from 5.5 to 7.5 μm, were synthesized by means of pyrolysis of polypropylene and maleated polypropylene in an autoclave. The characterization of structure and morphology was carried out by X-ray diffractometer (XRD), field-emission scanning electron microscopy (FESEM), (high resolution) transmission electron microscope [(HR)TEM)], selected-area electron diffraction (SAED) and Raman spectrum. As a typical morphology, the possible growth process of MCNTs was also investigated and discussed. The results of nitrogen adsorption-desorption indicate that the Brunauer-Emett-Teller (BET) surface area (140.6 m2/g) of the MCNTs obtained at 600 oC is about twice as that (74.5 m2/g) of carbon nanotubes obtained at 700 oC. The results of catalytic experiment show that MCNTs based catalyst has higher catalytic activity than the carbon nanotubes based catalyst for the preparation of methanol and dimethoxy-ethane by oxidation of dimethyl ether.

  16. Effect of wollastonite and talc on the micromechanisms of tensile deformation in polypropylene composites

    International Nuclear Information System (INIS)

    The work presented here describes the effect of wollastonite and talc on the micromechanisms of surface deformation and subsequent propagation into the bulk of low and high crystallinity polypropylenes during tensile straining. The potential of high resolution electron microscopy is utilized to examine deformation processes, and develop deformation mechanism maps. While mineral-reinforced polypropylenes exhibited an increase in tensile modulus, yield strength remained unaffected. Crystallization behavior indicated that the reinforcement minerals increase the rate of nucleation with consequent increase in percentage of bulk crystallinity. The reinforcement of polypropylene with wollastonite or talc alters the primary micromechanism of deformation from deformation bands/crazing in neat polypropylenes to wedge/ridge tearing in mineral-reinforced low crystallinity polypropylene composites. However, wedges were absent in high crystallinity polypropylene composites. The final fracture in reinforced polypropylene occurs by a mixed mode consisting of fibrillation and brittle mode, while crazing-tearing and brittle deformation are fracture modes for neat polypropylenes

  17. Plasma modification of polypropylene surfaces and its alloying with styrene in situ

    International Nuclear Information System (INIS)

    The treatment of polypropylene surfaces has been studied by dielectric barrier discharges plasma of Ar. The structure and morphology of polypropylene surfaces of Ar plasma modification are characterized by X-ray photoelectron spectroscopy, Fourier transform infrared spectrometers and scanning electron microscope. The modified by plasma treatment of iPP (isotactic polypropylene) surface properties have been examined in a determination of free radicals. The modified active surfaces of polypropylene can induce grafting copolymerization of styrene onto polypropylene. The structure of grafting copolymer is characterized and the grafting percent of styrene onto polypropylene is calculated. The homopolymer of styrene can be formed under grafting copolymerization of styrene onto polypropylene, which follows that the alloying of polypropylene with styrene is achieved in situ.

  18. Reacción tisular a materiales de sutura no absorbibles en piel de equinos Tissue reaction to nonabsorbable suture materials in horse skin

    Directory of Open Access Journals (Sweden)

    F Maldonado

    2006-01-01

    Full Text Available Se evaluó clínica e histológicamente el grado de reacción tisular frente a cuatro materiales de sutura no absorbibles (lino, nylon, caprolactam polimerizado y polipropileno, implantados en la piel de 8 equinos. Se determinó clínicamente el edema provocado y la ausencia o presencia de exudado a los 5 y 10 días de haber sido implantados los materiales de sutura, además al 10º día se realizó una biopsia para determinar histológicamente el grado de reacción tisular. Los resultados obtenidos mostraron que el lino causó un mayor edema al día 5, mientras que al día 10 el nylon y caprolactam provocaron un menor de edema. Con respecto a la presencia o ausencia de exudado, al día 5 la sutura de nylon fue la única que no presentó exudado en ninguno de los 8 ejemplares, sin embargo, al día 10, salvo un ejemplar que presentó exudado en todos los materiales, el nylon, caprolactam y polipropileno no presentaron exudado. En cuanto a la evaluación histológica tanto el nylon como el caprolactam mostraron menor grado de reacción tisular. En conclusión, el lino resultó tener el mayor grado de reacción tisular durante el presente estudio, y el nylon si bien es similar al caprolactam y polipropileno respecto a la reacción tisular, causó una menor cantidad de equinos con presencia de exudado que los otros materiales utilizados.The degree of tissue reaction of 4 nonabsorbable suture materials (linen, nylon, polymerized caprolactum and polypropylene implanted into health skin of 8 horses was clinically and histologically evaluated. Cutaneous oedema and absence or presence of the exudation were clinically evaluated 5 and 10 days following suture material implantation. Biopsies were taken to histologically evaluate tissue reaction at 10 days. The results obtained showed that linen caused more oedema by the 5th day, whereas the nylon and caprolactum had less oedema on the 10th day. With respect to the presence or absence of exudation, nylon was the only material which did not show exudation by the 5th day in any of the 8 samples, but on the 10th day, neither the nylon, caprolactum or polypropylene showed exudation, except one horse that showed exudation for all suture materials. The histological evaluation showed that nylon and caprolactum caused less tissue reaction. In conclusion, linen was found to have a higher degree of tissue reaction in the present study, and nylon although similar to caprolactum and polypropylene in terms of tissue reaction, caused less cases of exudate than the other suture materials used.

  19. Production of high melt strength polypropylene by gamma irradiation

    Science.gov (United States)

    Lugão, A. B.; Artel, B. W. H.; Yoshiga, A.; Lima, L. F. C. P.; Parra, D. F.; Bueno, J. R.; Liberman, S.; Farrah, M.; Terçariol, W. R.; Otaguro, H.

    2007-11-01

    High melt strength polypropylene (HMS-PP) has been recently developed and introduced in the market by the major international producers of polypropylene. Therefore, BRASKEM, the leading Brazilian PP producer, together with EMBRARAD, the leading Brazilian gamma irradiator, and the IPEN (Institute of Nuclear Energy and Research) worked to develop a national technology for the production of HMS-PP. One of the effective approaches to improve melt strength and extensibility is to add chain branches onto polypropylene backbone using gamma radiation. Branching and grafting result from the radical combinations during irradiation process. Crosslinking and main chain scission in the polymer structure are also obtained during this process. In this work, gamma irradiation technique was used to induce chemical changes in commercial polypropylene with two different monomers, Tri-allyl-isocyanurate (TAIC) and Tri-methylolpropane-trimethacrylate (TMPTMA), with concentration ranging from 1.5 to 5.0 mmol/100 g of polypropylene. These samples were irradiated with a 60Co source at dose of 20 kGy. It used two different methods of HMS-PP processing. The crosslinking of modified polymers was studied by measuring gel content melt flow rate and rheological properties like melt strength and drawability. It was observed that the reaction method and the monomer type have influenced the properties. However, the concentration variation of monomer has no effect.

  20. Comparison of life cycle assessment for different volume polypropylene jars

    Directory of Open Access Journals (Sweden)

    Krki? Nevena M.

    2012-01-01

    Full Text Available When deciding what packaging is the most appropriate for a product there are many factors to be considered. One of them is the impact of the packaging on environment. In this work, life cycle inventory and life cycle assessment of two different volume packagings were compared. The data were collected on the types and amounts of materials and energy consumption in the process of packaging and distribution of hand cream packed in polypropylene jars of 200 and 350 mL. Life cycle inventory (LCI and life cycle impact assessment (LCA were calculated. It was found that the total mass flow was higher for the jars of 350 mL. After analyzing individual flows, it was found that in both cycles (polypropylene jars of 200 and 350 mL,the consumption of fresh water was a dominant flow. This fresh water flow is mostly (95% consumed in the injection molding process of manufacturing jars from polypropylene granules. The LCA analysis showed no significant difference in global warming potential between different volume jars. The process that mostly affected global warming was the production of polypropylene jars from polypropylene granules by injection molding for both jar volumes. Judging by the global warming potential, there is no difference of the environmental impact between investigated jars, but considering the mass flow and water consumption, more environmental friendly were the 200 mL jars.

  1. Contribution of Thermal Modelisation to Understand adhesion Mechanisms in Extrusion Coating: Case of Polypropylene on Aluminium

    OpenAIRE

    Devisme, Samuel; Haudin, Jean-Marc; Agassant, Jean-François; Rauline, Damien; Chopinez, Fabrice

    2006-01-01

    A multilayered structure (polypropylene/grafted polypropylene/aluminium) manufactured by extrusion coating has been studied. The polypropylene film is extruded through a slit die, slightly stretched in air, coated on an aluminium foil in a laminator consisting of a chill roll and a flexible pressure roll, and finally cooled on successive chill rolls. Adhesive properties of polypropylene can be improved by grafting maleic anhydride on the polymer chain which may react with the aluminium surfac...

  2. Randomized clinical trial comparing manual suture and different models of mechanical suture in the mimicking of bariatric surgery in swine

    Directory of Open Access Journals (Sweden)

    Fernandes MA

    2014-02-01

    Full Text Available Marcos AP Fernandes,1 Bruno MT Pereira,2 Sandra M Guimarães,1 Aline Paganelli,3 Carlos Manoel CT Pereira,1 Claudio Sergio Batista4 1Institute of Obesity and Advanced Video Laparoscopic Surgery of Petropolis, Rio de Janeiro, Brazil; 2Division of Trauma, University of Campinas, São Paulo, Brazil; 3Laboratório de Patologia Micron Cell Diagnóstico, Rio de Janeiro, Brazil; 4Department of Gynecology and Obstetrics, Faculty of Medicine of Petropolis, Rio de Janeiro, Brazil Context and objective: Variations in the ability of surgeons served as motivation for the development of devices that, overcoming individual differences, allow the techniques to be properly performed, and of which the end result was the best possible. Every technique must be reproduced reliably by the majority of surgeons for their results to be adopted and recognized as effective. The aim of this study was to compare the results, from the point of view of anatomic pathology, of manual sutures versus mechanical sutures using different models of linear mechanical staplers, in the procedure of gastroenteroanastomosis and enteroanastomosis in swine. Methods: Thirty-six healthy, adult, male Sus scrofa domesticus pigs, weighing between 20.7 and 25.5 kg, were used. The swine were randomly divided into four groups of nine pigs, according to the type of suture employed: group A, manual suture with Polysorb® 3-0 wire; group B, 80-shear linear stapler (Covidien® Gia 8038-S; group C, 75-shear linear stapler (Ethicon® Tlc 75; and group D, 75-shear linear stapler (Resource® Yq 75-3. A temporal study was established on the seventh postoperative day for histopathological analysis, and the degree of inflammation, fibrosis, and newly formed vessels, as well as the presence or absence of granulation tissue, foreign body granuloma, and necrosis were all evaluated qualitatively and semiquantitatively. The results were analyzed statistically. Results: Observations during the histopathological analysis included the formation of foreign body granuloma in the gastroenteroanastomosis and enteroanastomosis in 88.9% of the swine that underwent manual suture and in none of the swine that underwent stapling. There was also a significant statistical difference among swine from Group A, and those from groups B, C and D regarding the degree of inflammation, being more intense in those swine that underwent manual suture. Conclusion: This study shows that both types of suture promoted proper healing of gastroenteroanastomosis and enteroanastomosis, although there was a higher degree of inflammation and an increased occurrence of foreign body granuloma in swine subjected to manual suture, although there have been similarities in safety, efficiency, and effectiveness between the models of linear mechanical staplers tested during the performance of these anastomoses on swine. Keywords: linear mechanical stapler, stapler, manual suture, surgery, gastroenteroanastomosis, enteroanastomosis, swine, randomized clinical trial

  3. HUESOS SUTURALES EN EL PTERION SUTURAL BONES IN THE PTERION

    Directory of Open Access Journals (Sweden)

    M. T. T. Braga

    2000-01-01

    Full Text Available Las variaciones de los huesos del cráneo son de interés para la anatomía, antropología física, imagenología y medicina legal. Con el propósito de aportar mayores detalles sobre los huesos suturales que se presentan en el pterion, fueron analizados 205 cráneos secos de individuos brasileños, adultos, de ambos sexos, blancos y no blancos. El hueso sutural fue observado en 31 cráneos (15,1%, localizándose 19 en el lado derecho (61,3%, 8 en el izquierdo (25,8% y 4 en ambos lados (12,9%. Con relación al sexo, 14 estuvieron presentes en cráneos masculinos (45,2% y 17 en femeninos (54,8%. En relación al grupo étnico, 20 eran del grupo blancos (64,5% y 11 de no blancos (35,5%. Las articulaciones de este hueso sutural con los huesos vecinos fueron clasificados en 4 tipos: Tipo I, donde se articuló con los huesos frontal, parietal, ala mayor del esfenoides y temporal, disposición encontrada en 17 cráneos (54,8%; Tipo II, donde se articuló con el parietal, temporal y ala mayor del esfenoides, encontrado en 11 cráneos (35,5%; Tipo III, donde se articuló con el temporal, frontal y ala mayor del esfenoides, observado en 2 cráneos (6,5 % y Tipo IV, donde se articuló con el parietal, frontal y ala mayor del esfenoides, encontrado en 1 cráneo (3,2%. Correlacionando las variables lado, sexo, grupo étnico y hueso sutural, el análisis estadístico reveló que la presencia de estos huesos es significativa en los individuos blancos y en el lado derechoCranium bones variations have been an object of interest for Anatomy, Physical Anthropology, X-Rays and Tomographic Images and Forensic Medicine. The aim of this article is to increase the knowledge of anatomical details about a sutural bone localized in the pterion. We observed 205 cranium of adult cadavers from Brazilian origin, of both sexs, white and non white ethnic group. The sutural bone was found in 31 cranium (15.1%, 19 in the right side (61.3%, 8 in the left side (25.5% and 4 in both sides (12.9%. In respect of the sex, 14 were observed in male cranium (45.2% and 17 in female cranium (54.8%. With respect to the ethnic group, 20 cases (64.5% corresponded to white individuals and 11 (35.5% to non white. Sutural bone joints with the next bones, were classified in four groups: Type I, the sutural bone joined with the frontal, parietal, greater wing of the sphenoid and temporal bones, this type was observed in 17 cranium (54.8%; Type II, it joined with the greater wing of the sphenoid, parietal and temporal bones, this type was observed in 11 cranium (35.5%; Type III, the sutural bone joined with the greater wing of the sphenoid, temporal and frontal bones, this type was observed in only 2 cranium (6.5% and Type IV, it joined with the greater wing of the sphenoid, parietal and frontal bones, this type was observed in only 1 cranium (3.2%. The statistical analysis of the different variables considered in this article showed that the presence of these bones is significative in white individuals and also in the right side in respect of all specimens

  4. HUESOS SUTURALES EN EL PTERION / SUTURAL BONES IN THE PTERION

    Scientific Electronic Library Online (English)

    M. T. T., Braga; C., Gabrielli; A, De Souza; C. F. S., Rodrigues; J. C., Marino.

    Full Text Available Las variaciones de los huesos del cráneo son de interés para la anatomía, antropología física, imagenología y medicina legal. Con el propósito de aportar mayores detalles sobre los huesos suturales que se presentan en el pterion, fueron analizados 205 cráneos secos de individuos brasileños, adultos, [...] de ambos sexos, blancos y no blancos. El hueso sutural fue observado en 31 cráneos (15,1%), localizándose 19 en el lado derecho (61,3%), 8 en el izquierdo (25,8%) y 4 en ambos lados (12,9%). Con relación al sexo, 14 estuvieron presentes en cráneos masculinos (45,2%) y 17 en femeninos (54,8%). En relación al grupo étnico, 20 eran del grupo blancos (64,5%) y 11 de no blancos (35,5%). Las articulaciones de este hueso sutural con los huesos vecinos fueron clasificados en 4 tipos: Tipo I, donde se articuló con los huesos frontal, parietal, ala mayor del esfenoides y temporal, disposición encontrada en 17 cráneos (54,8%); Tipo II, donde se articuló con el parietal, temporal y ala mayor del esfenoides, encontrado en 11 cráneos (35,5%); Tipo III, donde se articuló con el temporal, frontal y ala mayor del esfenoides, observado en 2 cráneos (6,5 %) y Tipo IV, donde se articuló con el parietal, frontal y ala mayor del esfenoides, encontrado en 1 cráneo (3,2%). Correlacionando las variables lado, sexo, grupo étnico y hueso sutural, el análisis estadístico reveló que la presencia de estos huesos es significativa en los individuos blancos y en el lado derecho Abstract in english Cranium bones variations have been an object of interest for Anatomy, Physical Anthropology, X-Rays and Tomographic Images and Forensic Medicine. The aim of this article is to increase the knowledge of anatomical details about a sutural bone localized in the pterion. We observed 205 cranium of adult [...] cadavers from Brazilian origin, of both sexs, white and non white ethnic group. The sutural bone was found in 31 cranium (15.1%), 19 in the right side (61.3%), 8 in the left side (25.5%) and 4 in both sides (12.9%). In respect of the sex, 14 were observed in male cranium (45.2%) and 17 in female cranium (54.8%). With respect to the ethnic group, 20 cases (64.5%) corresponded to white individuals and 11 (35.5%) to non white. Sutural bone joints with the next bones, were classified in four groups: Type I, the sutural bone joined with the frontal, parietal, greater wing of the sphenoid and temporal bones, this type was observed in 17 cranium (54.8%); Type II, it joined with the greater wing of the sphenoid, parietal and temporal bones, this type was observed in 11 cranium (35.5%); Type III, the sutural bone joined with the greater wing of the sphenoid, temporal and frontal bones, this type was observed in only 2 cranium (6.5%) and Type IV, it joined with the greater wing of the sphenoid, parietal and frontal bones, this type was observed in only 1 cranium (3.2%). The statistical analysis of the different variables considered in this article showed that the presence of these bones is significative in white individuals and also in the right side in respect of all specimens

  5. Dynamic mechanical characterization and modelling of polypropylene based organoclay nanocomposite

    Directory of Open Access Journals (Sweden)

    Wang Kui

    2015-01-01

    Full Text Available In order to investigate the dynamic behaviour of polypropylene based organoclay nanocomposite, the polypropylene matrix and a master batch of polypropylene modified anhydrid maleic were mixed by means of melt mixing technique. The experimental characterization was performed by using split Hopkinson pressure bars (SHPB, at different strain rates and temperatures. A significant increase of the yield stress of nanocomposite was shown with the present of organoclay, comparing to neat PP. A three-phase approach based on the micromechanical formulation of the cooperative model is proposed to model the yield behaviour of the polymer nanocomposite. Our proposed approach accounts for strain rate and temperature effects as well as the organoclay exfoliation effect. The predictions of models for the nanocomposite yield behaviour showed a good agreement with experimental data.

  6. Surface and mechanical properties of polypropylene/clay nanocomposite

    Directory of Open Access Journals (Sweden)

    Dibaei Asl Husein

    2013-01-01

    Full Text Available Huge consumption of polypropylene in the industries like automotive motivates academic and industrial R&Ds to find new and excellent approaches to improve the mechanical properties of this polymer, which has no degradation effect on other required performance properties like impact resistance, controlled crystallinity, toughness and shrinkage. Nowadays, nanoparticles play a key role in improving the mechanical and surface properties of polypropylene. In this study, three compositions of "Polypropylene/nanoclay", containing 0%, 2% and 5% of nanoclay were prepared in internal mixer. For characterizing the nanoclay dispersion in polymer bulk, TEM and XRD tests were used. For scratch resistance test, scratch lines were created on the load of 900 grain on sheets and SEM images were taken and compared with neat PP scratch image. Crystallinity and mechanical behavior were studied. The results showed that mechanical properties and scratch resistance of the composites have been improved.

  7. Gamma radiation resistance of tale-polypropylene composite materials

    International Nuclear Information System (INIS)

    Samples of isostatic polypropylene mixed with 10, 20 and 30 wt.% Talc were prepared. Sample films were gamma irradiated at 10 - 300 k Gy under air. The results from DSC suggested that fine particles of Talc showed pronounced nucleating effect by increasing the rate of crystallization and thermal stability. However, Talc-filled composites did not showed radiation resistant property. Absorbance intensity of carbonyl and hydroperoxide indicated the amount of oxidative degradation were increased with increasing radiation dose but would not depend on the Talc content. Talc was found to enhance polypropylene embrittlement and to lower the mechanical properties. However at appropriate concentration of Talc and low gamma dose. It is possible to improve the mechanical properties of the composites. In the field of environmental study, Talc-filled composites of iso tactic polypropylene may be used as a degradable plastic

  8. Separation of mineral oil droplets using polypropylene fibre bed coalescence

    Directory of Open Access Journals (Sweden)

    Govedarica Dragan D.

    2015-01-01

    Full Text Available This paper investigates the separation possibilities of model emulsion oil-in-water using polypropylene fibre bed coalescence. Experiments were carried out over a wide range of physico-chemical characteristics of mineral oils, bed permeability and operating fluid velocities. The aim of this study was to analyse the influence of the dispersed oil phase nature and of the bed geometry on the separation efficiency. From the obtained results, it can be concluded that polypropylene fibres in the broadest studied range of bed permeabilities and fluid velocities, effectively separate oil that is highly polar. On the contrary, for the other two investigated oils at low values of bed permeability a region was detected in which the coalescer is incapable to operate. It has to be emphasized that the polypropylene fibres efficiently separate all three investigated oils at the highest studied bed permeability. [Projekat Ministarstva nauke Republike Srbije, br. 172022

  9. Antioxidant action in irradiated polypropylene studied by ultraviolet spectroscopy

    International Nuclear Information System (INIS)

    Ultraviolet spectrum of 0.2 mm thick film of polypropylene containing 0.5% ORGANOX 1010 showed that in the sample prepared by slow cooling about 15% of the antioxidant reacted during the preparation process. The difference in turbidity between the samples obtained in the slow and the fast cooling process is attributed to the degree of crystallinity, which is in agreement with the DSC data. Very pronounced effects of the oxygen concentration and the degree of crystallinity on antioxidant uptake in irradiated polypropylene films were observed and discussed. It was also shown that a Febetron 707 pulsed electron accelerator is capable of producing both the single pulse dose (50 kGy) and the dose rate (2.5 TGy/s) large enough to enable a comparison of dose rate effects and LET effects in the study of the antioxidant reactions in polypropylene

  10. Suture contamination by surface powders on surgical gloves.

    Science.gov (United States)

    Khan, M A; Brown, J L; Logan, K V; Hayes, R I

    1983-06-01

    Recent studies have shown that many glove manufacturers still are using talc as a glove-mold release agent. The removal of talc particles from the patient-contact side of the gloves is difficult and incomplete with the use of recommended washing and wiping procedures. As a result, a shedding hazard exists that may ultimately be related to granulomatous reactions. In our study, shedding was demonstrated to be hazardous because of suture contamination with talc particles. PMID:6847370

  11. Transcutaneous Serdev Suture For Buttock’s Lift

    OpenAIRE

    Nikolay Serdev

    2013-01-01

    This article presents the author's technique and experience in the treatment of the flaccid "unhappy buttock" form with his surgical procedure of buttock lift by suture, without incision scars. The author first presented this new operation technique on a national level at the 2nd Annual Meeting of the National Bulgarian Society for Aesthetic Surgery and Aesthetic Medicine in Sofia on March 18, 1994 [1] and internationally at many scientific meetings over the world [2, 3, 4…]. The result is a ...

  12. Comparison of Subcuticular Suture Materials in Cesarean Skin Closure

    OpenAIRE

    P?nar Solmaz Hasdemir; Tevfik Guvenal; Hasan Tayfun Ozcakir; Faik Mumtaz Koyuncu; Gonul Dinc Horasan; Mustafa Erkan; Semra Oruc Koltan

    2015-01-01

    Aim. Comparison of the rate of wound complications, pain, and patient satisfaction based on used subcuticular suture material. Methods. A total of 250 consecutive women undergoing primary and repeat cesarean section with low transverse incision were prospectively included. The primary outcome was wound complication rate including infection, dehiscence, hematoma, and hypertrophic scar formation within a 6-week period after operation. Secondary outcomes were skin closure time, the need for use ...

  13. Arthroscopic Absorbable Suture Fixation for Tibial Spine Fractures

    OpenAIRE

    Verdano, Michele Arcangelo; Pellegrini, Andrea; Lunini, Enricomaria; Tonino, Pietro; Ceccarelli, Francesco

    2013-01-01

    The purpose of this technical note and accompanying video is to describe a modified arthroscopic suture fixation technique to treat tibial spine avulsion fractures. Twenty-one patients underwent arthroscopic treatment for tibial spine avulsion with our technique; they were clinically and biomechanically evaluated at 2 years' follow-up and showed optimal clinical and radiographic outcomes. Repair with this arthroscopic technique provides a significant advantage in the treatment of type III and...

  14. Geophysical images of the deep crust: the Iapetus suture

    OpenAIRE

    Beamish, D.; Smythe, D.K.

    1986-01-01

    The Iapetus suture, arguably the most fundamental lineament of British and Irish structure, has been previously identified on the BIRPS WINCH deep seismic reflection profiles offshore as a NW-dipping feature. New depth-migrated interpretations of these and other reflection data show good correlation of structure for 100 km along strike in the northern Irish Sea towards magnetotelluric stations onshore in the north of England and Southern Uplands of Scotland. Three different methods of inverti...

  15. Suturing of digital lacerations: digital block or local infiltration?

    OpenAIRE

    Evans, David M

    1991-01-01

    A prospective trial was carried out to assess the relative efficiency of digital block and local infiltration as methods of anaesthesia when suturing lacerations of the digits. A standard technique and questionnaire were applied to a consecutive group of 62 patients attending the Accident Department of the Bristol Royal Infirmary. Digital block was found to be a more effective technique than local infiltration for anaesthetising digital lacerations.

  16. ADJUSTABLE SUTURE STRABISMUS SURGERY: A REVIEW OF 850 CASES

    Directory of Open Access Journals (Sweden)

    M.E. Latronico

    2012-05-01

    Full Text Available Purpose. The aim of the study is to investigate the relationship between the different kinds of squint and the adjustament re- quired in post-op. Methods. Our personal case histories concerns 850 patients that underwent adjustable suture strabismus surgery during the last ten years, examinated in our Department of Ophtalmology over the period 2000-2009. The same surgeon (G.L. performed adjustable suture strabismus surgery as routine duties, whether on horizontal or vertical rectus muscles, but never on oblique muscles. Adjustments were always performed in the 24 postoperative hours. With regard to the relationship between previous surgeries, and requested regulation: 669 cases not underwent previous sur- gery; 181 cases peviously underwent surgery one or more times. results. First we seek for the statistical significant difference between the various results found, computing X2, ? and the rel- ative risk. We can conclude by saying that who made a vertical muscle squint surgery presents a relative risk of 3 times greater to take hypocorrection rather than hypercorrection and that who made before squint surgery presents a relative risk of 2,72 times greater to take regulation. Conclusions. We predicted this result because it confirms that the use of adjustable suture is the more frequent as the muscle fibrosis is the more significant. And the fibrosis is an usual outcome of previous squint surgery.

  17. Preparation of organophilic clays and polypropylene nano composites

    International Nuclear Information System (INIS)

    Polypropylene/montmorillonite nano composites were prepared by the melt intercalation technique. The clay was organically modified with different quaternary ammonium salts to obtain the organo clay. The modified clays with the quaternary ammonium salts were introduced in a polypropylene matrix with 3 wt. % of clay. The interlayer distance (d001) of the clay particles were obtained by X- ray diffraction and the thermal stability of the systems were investigated by thermogravimetry. The organo clay presence in the polymer matrix increased the degradation temperature in relation to the pure polymer. (author)

  18. Investigation into effects of environmental radiation on polypropylene bags

    International Nuclear Information System (INIS)

    Polypropylene woven bags were exposed to environmental conditions over a period of time. Samples were removed from woven bags and the tensile properties examined using an extensometer. Molar mass changes were monitored by dilute viscosity measurements. The concentration of the stabilisers was determined using UV spectroscopy. This study established the behaviour of polypropylene tapes under environmental conditions. The mechanical properties of the samples were found to deteriorate with exposure time. Also, the amount of stabiliser reduced with aging time whilst the molar mass increased suggesting crosslinking of the material occurring. The results of the study suggest that there was no difference in the performance between the stabilised and the unstabilised samples. (author)

  19. Evaluation of polypropylene/saw dust composites prepared with maleated polypropylene (mapp) produced by reactive extrusion

    Scientific Electronic Library Online (English)

    Ernani, Trombetta; Thais, Flores-Sahagun; Kestur G., Satyanarayana.

    Full Text Available Considering the importance of the environment and fuel economy, the Brazilian automotive industry has focused on the development of lightweight materials based on renewable resources. Replacement of PP- talc composite by PP- saw dust composite is a promising possibility. This paper presents the prep [...] aration of maleated polypropylene (MAPP) through reactive extrusion using different amounts of peroxides and maleic anhydride as well its characterization. Using 20% of saw dust coated with different amounts of prepared MAPP, several composites were prepared including one with commercial MAPP. Injection molded samples of all these composites along with that without the compatibilizer were characterized for mechanical properties. These studies indicated fulfilling the proposed objectives: (i) finding the optimal reactive extrusion conditions to prepare MAPP samples; (ii) preparation of PP/saw dust composites with and without MAPP coating; (iii) to arrive at optimized composite to get the best performance through their characterization for various properties of all the produced composites.

  20. Influence of different types of surgical suture materials on mehanical damage of oral mucosa

    Directory of Open Access Journals (Sweden)

    Mirkovi? Siniša

    2011-01-01

    Full Text Available Introduction. Throughout history many kinds of different suture materials have been used for closing and suturing surgical wounds. Medical literature describes four basic characteristics of suture material: knot safety, tensile strength, tissue reaction and wound safety. The tissue reaction is reflected in an inflammatory response, which, though minimal, occurs during first two to seven days after implanting suture into the tissue. The aim of this research was to investigate whether different suture materials affect the development of decubital damage of oral mucosa, which to a great extent can compromise the process of wound healing. Material and methods. The investigation was designed as a prospective clinical study including 150 patients of both genders, aged between 25 and 60. The patients were distributed into three groups of 50 persons. The suture Black Silk was used in the first group, designated as a control group. Nylon and Vicril were used in the second and third group, i.e. experimental groups, respectively. Decubital damage of the surrounding soft tissues was the main parameter for monitoring the effects of selected suture materials on the oral mucosa. Conclusion. The comparison of results obtained for the investigated suture materials after suturing oral mucosa revealed that certain advan­tage could be given to synthetic monofilament suture materials

  1. Análise das aderências resultantes da fixação de telas cirúrgicas com selantes de fibrina e sutura: modelo experimental intraperitoneal / Analysis of adhesions resulted from mesh fixation with fibrin sealant and suture: experimental intraperitoneal model

    Scientific Electronic Library Online (English)

    Juliano Hermes Maeso, Montes; André Vicente, Bigolin; Renata, Baú; Roberto, Nicola; João Vicente Machado, Grossi; Cláudia Juliana, Loureiro; Leandro Totti, Cavazzola.

    2012-12-01

    Full Text Available OBJETIVO: Comparar fixação cirúrgica de telas de polipropileno (PP) e telas de polipropileno revestido (PCD), usando fio de sutura de polipropileno e cola biológica, quanto à formação de aderências intraperitoneais. MÉTODOS: Amostra de 46 ratas Wistar, randomizadas em seis grupos: dois grupos-contro [...] le, com cinco ratas cada, que foram submetidos um à incisão medial (IM) e o outro à uma incisão em forma de U (IU); nenhum desses grupos recebeu tela. Dois grupos com tela de PP, um com dez ratas, fixada com sutura (PPF), e o outro, com seis ratas, fixada com cola biológica (PPC). E Dois grupos com tela de PCD, no primeiro, com dez animais, a tela foi fixada com sutura (PCDF), e no segundo, com dez animais, com cola biológica (PCDC). RESULTADOS: Após o prazo de 21 dias, os grupos-controle não apresentaram aderências significantes. O grupo PPC apresentou menor grau de aderência do que o grupo PPF (p=0,01). Não houve diferença entre as fixações nos grupos com PCD. CONCLUSÃO: A comparação da fixação apresentou diferença estatística significativa apenas à tela de PP, com menor grau de aderência utilizando a cola. As aderências se localizaram predominantemente nas extremidades das telas estudadas. Abstract in english OBJECTIVE: To compare surgical fixation of polypropylene mesh (PP) and coated polypropylene mesh (PCD) using polypropylene suture and fibrin glue, as for the formation of intraperitoneal adhesions. METHODS: A sample of 46 female Wistar rats were randomized into six groups: two control groups, with f [...] ive rats each, were subjected to one medial incision (MI) and the other to a U-shaped incision (UI), none of these groups received the mesh. Two groups of PP mesh, with ten rats, fixed with suture (PPF), the other with six rats, fixed with biological glue (PPC). And two groups of PCD mesh, at first, with ten animals, the mesh was fixed with sutures (PCDFs) and the second with ten animals with biological glue (PCDC). RESULTS: After 21 days, the control groups showed no significant adhesions. The PPC group showed a lower degree of adhesion than the PPF group (p = 0.01). There was no difference between the groups with PCD. CONCLUSION: Comparison of fixation was statistically different only with PP mesh, with lesser degrees of adherence when using the glue. Adhesions were predominantly located at the extremities of the meshes studied.

  2. Análise das aderências resultantes da fixação de telas cirúrgicas com selantes de fibrina e sutura: modelo experimental intraperitoneal Analysis of adhesions resulted from mesh fixation with fibrin sealant and suture: experimental intraperitoneal model

    Directory of Open Access Journals (Sweden)

    Juliano Hermes Maeso Montes

    2012-12-01

    Full Text Available OBJETIVO: Comparar fixação cirúrgica de telas de polipropileno (PP e telas de polipropileno revestido (PCD, usando fio de sutura de polipropileno e cola biológica, quanto à formação de aderências intraperitoneais. MÉTODOS: Amostra de 46 ratas Wistar, randomizadas em seis grupos: dois grupos-controle, com cinco ratas cada, que foram submetidos um à incisão medial (IM e o outro à uma incisão em forma de U (IU; nenhum desses grupos recebeu tela. Dois grupos com tela de PP, um com dez ratas, fixada com sutura (PPF, e o outro, com seis ratas, fixada com cola biológica (PPC. E Dois grupos com tela de PCD, no primeiro, com dez animais, a tela foi fixada com sutura (PCDF, e no segundo, com dez animais, com cola biológica (PCDC. RESULTADOS: Após o prazo de 21 dias, os grupos-controle não apresentaram aderências significantes. O grupo PPC apresentou menor grau de aderência do que o grupo PPF (p=0,01. Não houve diferença entre as fixações nos grupos com PCD. CONCLUSÃO: A comparação da fixação apresentou diferença estatística significativa apenas à tela de PP, com menor grau de aderência utilizando a cola. As aderências se localizaram predominantemente nas extremidades das telas estudadas.OBJECTIVE: To compare surgical fixation of polypropylene mesh (PP and coated polypropylene mesh (PCD using polypropylene suture and fibrin glue, as for the formation of intraperitoneal adhesions. METHODS: A sample of 46 female Wistar rats were randomized into six groups: two control groups, with five rats each, were subjected to one medial incision (MI and the other to a U-shaped incision (UI, none of these groups received the mesh. Two groups of PP mesh, with ten rats, fixed with suture (PPF, the other with six rats, fixed with biological glue (PPC. And two groups of PCD mesh, at first, with ten animals, the mesh was fixed with sutures (PCDFs and the second with ten animals with biological glue (PCDC. RESULTS: After 21 days, the control groups showed no significant adhesions. The PPC group showed a lower degree of adhesion than the PPF group (p = 0.01. There was no difference between the groups with PCD. CONCLUSION: Comparison of fixation was statistically different only with PP mesh, with lesser degrees of adherence when using the glue. Adhesions were predominantly located at the extremities of the meshes studied.

  3. Surface modification of polypropylene and compatibilization of interfaces in incompatible blends of polypropylene with polystyrene by plasma of CO2

    International Nuclear Information System (INIS)

    The effect of surface modification of polypropylene (PP) film is induced by CO2 plasma in this study. The change in chemical structures on the surface of PP film is characterized by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR). The polarity of modified surface of PP film is investigated by contact angle method. The compatibilization of interfaces between polypropylene and polystyrene phases in incompatible blends is studied by the treatment of plasma of CO2. Transition layer thickness is measured by small angle light scattering (SALS).

  4. Síntese da parede abdominal: avaliação de dois tipos de sutura contínua em ratos / Abdominal wall syntheses: comparison between two types of continuous suture

    Scientific Electronic Library Online (English)

    Vanessa Medeiros, Loureiro; Djalma José, Fagundes; Murched Omar, Taha.

    2003-06-01

    Full Text Available OBJETIVO: Comparar a sutura simples contínua e a sutura contínua em oito vertical no fechamento da parede abdominal de ratos. MÉTODOS: Quarenta e oito ratos machos Wistar, foram submetidos a laparotomia padronizada e fechamento da parede abdominal com sutura simples contínua (n=24) e sutura contínua [...] em oito-vertical (n=24), com fio de polipropileno. No 7° e 14° pós-operatório foram submetidos a eutanásia 12 animais de cada grupo e deles retirados a camada músculo-aponevrótica da parede abdominal envolvendo a cicatriz operatória e preparados para exames histológico e imunohistoquímico. Os segmentos levados ao exame histológico foram corados por Hematoxilina-eosina sendo feita observação qualitativa do processo cicatricial e Picrosirius red F3BA, para avaliação quantitativa do colágeno. Também foram estudadas as porcentagens de macrófagos na linha de sutura por imunohistoquímica. Para a quantificação de macrófagos e fibras colágenas foi utilizado avaliação histológica por digitalização de imagem, baseados nos princípios de espectrofotometria. Os dados encontrados foram analisados estatisticamente pelos testes qui-quadrado, exato de Fisher e Mann-Whitney (p Abstract in english PURPOSE: To establish morphologic relationship between the continuous "simple mass" suture and the continuous far-near, near-far mass suture of longitudinal midline abdominal incision. METHODS: A total of 48 male Wistar rats underwent longitudinal standard laparotomy with equal distribution to one o [...] f two groups: GI- continuous "simple mass" suture, GII-continuous far-near, near-far suture, both with polypropylene. On postoperative day 7th or14th, 12 animals of each group were submitted to euthanasia and anterior abdominal wall was removed (without skin) for histologic and immune- histochemistry analysis. The samples of the abdominal wall were stained by hematoxylin-eosin in order to performed a qualitative healing tissue reaction. Others samples were stained by Picrosirius red F3BA in order to performed a quantitative analysis of macrophages and collagen. Statistical analysis was done by use the chi-square test, Fisher exact test and Mann-Whitney variance test ( p

  5. Near-surface deformation in polypropylene blends

    Science.gov (United States)

    Tang, Honxiang

    Polypropylene blends with up to 20% rubber phase are known as thermoplastic polyolefin or TPO and have been widely used in the automotive industry in both painted and unpainted components. Poor scratch resistance and paint adhesion have been of great concern for TPO applications. The research described in this thesis has addressed both of these issues by studying the near-surface deformation under scratches in unpainted TPO, and the interfacial adhesion and deformation of painted TPO. A transmission electron microscopy approach has been developed to study the microstructure and microdeformation in this important class of engineering materials. It was observed that highly oriented near-surface material in injection-molded TPO plastically deformed by forming periodic shear bands under scratches. The material inside the shear band dilated as revealed by the difference in the angles between the shear band boundary and the rubber particles inside and outside the shear bands. The extent of material dilation inside the shear bands decreased with the distance from the free surface and increased with normal applied load. At high applied normal loads (>400 g), a significant amount of voiding caused by the debonding between the rubber phase and the PP matrix was observed. Talc particles were found to preferentially wet the rubber phase and this may prevent debonding between talc particles and the PP matrix as observed in talc-filled pure PP. The anisotropy in scratching behavior correlates with the anisotropy in mechanical properties. The morphology of the scratching deformation was found to be particularly sensitive to the near-surface structural anisotropy. A tensile cracking test was applied to quantitatively measure the interfacial adhesion between paint and TPO substrates. Interfacial structure between chlorinated polyolefin adhesion promoter and TPO substrate was studied by electron microscopy. The swelling of the rubber phase near the interface was observed, evidently arising from the interaction with the solvent in the paint and adhesion promoter. Diffusion of the rubber phase near the interface was also observed. Baking at high temperature enhanced both the swelling and interfacial diffusion of rubber phase. Paint adhesion was improved in TPO substrates with lower molecular weight PP homopolymer, which was ascribed to the enhanced interfacial diffusion.

  6. Effect of hot drawing process on physical and thermal properties of polypropylene fiber containing selective peroxide and comparison with conventional polypropylene fibers

    Scientific Electronic Library Online (English)

    Bahareh, Kalantari; Mohammad R. M., Mojtahedi; Ahmad M., Shoushtari; Aminoddin, Haji.

    Full Text Available In this research, the effect of the drawing process on the physical and thermal properties of commercially available polypropylene fiber containing selective peroxide was studied. Attempts have also been made to compare this drawn fiber sample with conventional polypropylene fibers produced from rea [...] ctor and with controlled rheology grades. The results showed that the drawn PP/Peroxide fiber has higher birefringence, tenacity, and initial modulus compared with that of the drawn polypropylene fiber. Moreover, the fraction of load carrying chains in various drawn polypropylene fibers was evaluated on the basis of simplified models.

  7. Effect of hot drawing process on physical and thermal properties of polypropylene fiber containing selective peroxide and comparison with conventional polypropylene fibers

    Directory of Open Access Journals (Sweden)

    Bahareh Kalantari

    2012-01-01

    Full Text Available In this research, the effect of the drawing process on the physical and thermal properties of commercially available polypropylene fiber containing selective peroxide was studied. Attempts have also been made to compare this drawn fiber sample with conventional polypropylene fibers produced from reactor and with controlled rheology grades. The results showed that the drawn PP/Peroxide fiber has higher birefringence, tenacity, and initial modulus compared with that of the drawn polypropylene fiber. Moreover, the fraction of load carrying chains in various drawn polypropylene fibers was evaluated on the basis of simplified models.

  8. CRUDE PALM OIL AS A BIOADDITIVE IN POLYPROPYLENE BLOWN FILMS

    Directory of Open Access Journals (Sweden)

    Emiliana Rose Jusoh,

    2012-01-01

    Full Text Available Growing public concern about environment and potential risks to health in the polymer and plasticizer industry promises to increase the market for a safer alternative plasticizer such as a vegetable oil-based agent. The purpose of this study was to investigate the potential of crude palm oil as a bio-additive in polypropylene blown films. The polypropylene was blended with 1%, 3%, and 5% dosages of CPO using a twin screw extruder. The extruded samples were blown using the blown thin film technique. Mechanical, physical, and morphological properties were characterized. Modifying polypropylene with CPO showed good enhancement in the mechanical properties of the polypropylene. Tensile strength, elongation at break, impact strength, and tear strength all increased. The scanning electron microscopy photographs of the CPO-modified PP clearly supported the results from the mechanical strength tests. The presence of CPO in the PP matrices decreased the density and increased the melt flow rate. These findings contribute new knowledge to the additives area and give important implications for designing and manufacturing polymer packaging materials.

  9. Conifer fibers as reinforcing materials for polypropylene-based composites

    DEFF Research Database (Denmark)

    Plackett, David; Chengzhi, Chuai; Almdal, Kristoffer; Poulsen, Lars

    2001-01-01

    Conifer fibers were used to reinforce polypropylene (PP). To improve the compatibility between the conifer fibers and the PP matrix, the fibers were either grafted with maleated PP (MAPP), treated by adding MAPP, or mixed with ethylene/propylene/diene terpolymer (EPDM). The treatments resulted in...

  10. Effects of high-energy electron radiation on polypropylene dielectric

    International Nuclear Information System (INIS)

    Polypropylene, a polymeric materials widely used as the main dielectric in many high-voltage components such as capacitors and cables, was exposed to electron irradiation in air at room temperature. The 25.4-?m-thick dry polypropylene films were irradiated to different doses up to 108 rads with electron beam having energies of 0.5, 1.0, and 1.5 MeV. Monoisopropyl biphenyl (MIPB)-impregnated polypropylene films were also exposed to 1-MeV electron beam to doses up to 108 rads and the post-irradiation effects on the electrical, mechanical, and morphological and chemical properties of the films were evaluated. The electrical properties included the AC, DC and pulsed breakdown strengths, dielectric constant, dissipation factor, conductivity, and pulsed life-endurance. The mechanical properties comprised the Young's modulus, elongation-at-break, tensile strength, complex modulus, and mechanical loss. Finally, the morphological and chemical diagnoses carried out included surface morphology, elemental analysis, crystallinity changes, and identification of newly formed bonds and degree of oxidation. The results obtained indicate that the dry polypropylene films started to exhibit degradation at doses as low as 106 rads. The properties that were mostly affected included the film's tensile properties, pulsed life, dissipation factor, and electrical conductivity

  11. Polypropylene/organoclay/SEBS nanocomposites with toughness-stiffness properties

    DEFF Research Database (Denmark)

    Sanporean (nee Potarniche), Catalina-Gabriela; Vuluga, Zina; Radovici, Constantin; Panaitescu, Denis Mihaela; Iorga, Michaela; Christiansen, Jesper deClaville; Mosca, Alessandra

    2014-01-01

    Polypropylene nanocomposites with a different amount of styrene-ethylene-butylene-styrene block copolymer (SEBS)/clay were prepared via a melt mixing technique. To improve the dispersion of commercial organoclay (denoted as OMMT), various amounts of SEBS were incorporated. At a fixed content of...

  12. Functional Block Copolymers as Compatibilizers for Nanoclays in Polypropylene Nanocomposites

    DEFF Research Database (Denmark)

    Jankova Atanasova, Katja; Daugaard, Anders Egede; Stribeck, Norbert; Zeinolebadi, Ahmad; Sari, Morteza Ganjaee; Potarniche, Catalina-Gabriela; Jensen, Erik Appel; Christiansen, Jesper de Claville; Hvilsted, Søren

    With the aim of creating tough nanocomposits (NC) [1] based on polypropylene (PP) and nanoclay (NCl) in the framework of the 7th EU program NANOTOUGH we have designed amphiphilic block copolymers utilizing Atom Transfer Radical Polymerization (ATRP) [2]. They consist of a hydrophobic block of...

  13. Packing parameters effect on injection molding of polypropylene nanostructured surfaces

    DEFF Research Database (Denmark)

    Calaon, Matteo; Tosello, Guido; Hansen, Hans Nørgaard; Ravn, C.; Islam, Aminul

    2012-01-01

    having a diameter of 500 nm was employed. The tool insert surface was produced using chemical-based-batch techniques such aluminum anodization and nickel electroplating. During the injection molding process, polypropylene (PP) was employed as material and packing phase parameters (packing time, packing...

  14. Propriedades mecânicas de nanocompósitos de polipropileno e montmorilonita organofílica / Mechanical properties of polypropylene and organophilic montmorillonite nanocomposites

    Scientific Electronic Library Online (English)

    Lucilene B. de, Paiva; Ana R., Morales; Thiago R., Guimarães.

    2006-06-01

    Full Text Available Neste trabalho foram preparados nanocompósitos de polipropileno e montmorilonita organofílica comercial Cloisite 20A em concentrações de 2,5%, 5,0%, 7,5% e 10,0% e polipropileno graftizado com anidrido maleico como agente compatibilizante pela técnica de intercalação do fundido em extrusora de dupla [...] rosca. Os materiais obtidos foram caracterizados por difração de raios x, ensaios de tração e impacto de acordo com as normas ASTM D638 e D256, respectivamente. Os resultados de difração de raios x indicaram a formação de nanocompósitos com estruturas parcialmente esfoliadas ou intercaladas, dependendo da composição, que proporcionaram aumento do módulo de elasticidade enquanto as propriedades de resistência ao impacto não foram satisfatórias. Abstract in english Nanocomposites of polypropylene and commercial montmorillonite organophilic Cloisite 20A containing 2.5%, 5%, 7.5% and 10% of clay with polypropylene-graft-maleic anhydride as coupling agent were prepared through the melt intercalation by twin-screw extruder. The materials were characterized by x-ra [...] y diffraction, tensile and impact properties according to ASTM D638 and D256 test methods, respectively. The x-ray diffraction results showed exfoliated or intercalated structures for different concentrations of the clay. The tensile modulus improved with the increase of the amount of the clay while the impact strength showed unsatisfactory results.

  15. Comparison of sutured and stapled closure of loop ileostomy after restorative proctocolectomy.

    OpenAIRE

    Bain, I M; Patel, R.; Keighley, M. R.

    1996-01-01

    Twenty consecutive stapled loop ileostomy closures in patients treated by restorative proctocolectomy were compared with the previous 20 sutured loop ileostomy closures in a non-randomised audit. Complications occurred in six of 20 stapled closures compared with seven of 20 sutured closures. Operating time and hospital stay were similar. The additional expense of stapling does not seem justified as complication rates, operating time and hospital stay are similar to sutured closures.

  16. On the equivalence of contact invariants in sutured Floer homology theories

    OpenAIRE

    Baldwin, John A.; Sivek, Steven

    2016-01-01

    We recently defined an invariant of contact manifolds with convex boundary in Kronheimer and Mrowka's sutured monopole Floer homology theory. Here, we prove that there is an isomorphism between sutured monopole Floer homology and sutured Heegaard Floer homology which identifies our invariant with the contact class defined by Honda, Kazez and Mati\\'c in the latter theory. One consequence is that the Legendrian invariants in knot Floer homology behave functorially with respect to Lagrangian con...

  17. Responses of intramembranous bone and sutures upon in vivo cyclic tensile and compressive loading

    OpenAIRE

    Peptan, Alexandra I.; Lopez, Aurora; Kopher, Ross A.; Mao, Jeremy J

    2007-01-01

    Cranial vault and facial sutures interpose between mineralized bones of the skull, and may function analogously to appendicular and cranial base growth plates. However, unlike growth plates that are composed of chondrocyte lineage, cranial and facial sutures possess heterogeneous cell lineages such as mesenchymal cells, fibroblasts, and osteoblasts, in addition to vascular-derived cells. Despite recently intensified effort, the biological responses of intramembranous bone and sutures to mecha...

  18. STUDY OF SKIN STAPLES AND CONVENTIONAL SUTURE FOR ABDOMINAL SKIN WOUND CLOSURE

    OpenAIRE

    Avinash K. Bhavikatti; Patil, R.B.; S. S. Karbhari

    2012-01-01

    Introduction: The use of automatic stapling device for skin closure has become more popular due to its minimum disadvantages as compared to conventional suturing. Hence, this study was undertaken to compare the time required for abdominal skin closure and pain during suture removal, between skin staplers and conventional suture.

    Materials and Methods: The study includes 1...

  19. End-on extramucosal single layer suture with double anchoring in the submucosa on rabbits

    OpenAIRE

    Nascimento Luiz Roberto do; Souza Virgínio Cândido Tosta de; Simões Manuel de Jesus; Ramos Eduardo Chibeni Fernandes; Bazzano Félix Carlos Ocáriz; Novo Neil Ferreira; Juliano Yara; Gomes Paulo de Oliveira

    1999-01-01

    The techniques of gastrointestinal surgical sutures have been frequently focused in controversial publications. These ones concern not only anastomosis? types but also about thread types and how to apply them. The values of the submucosa as layer of greatest resistence of the digestive tube was already known since the past century. The aim of this study is to avaluate the suture in an extramucosal single-layer suture with double anchoring of the submucosa, a technical detail not found in the...

  20. The shape memory effect in 50.3Mn-39.7Ni-10.0Al alloy

    International Nuclear Information System (INIS)

    The shape memory effect has been observed in 50.3Mn-39.7Ni-10.0Al alloy by thermal cycling under a load and bending at room temperature. A particular apparatus for bending tests is described. The second phase particles improve ductility of the intermetallic but result in incomplete shape recovery. Deformation of a dual phase material consisting the hard intermetallic matrix and the particles of the soft disordered phase is discussed. (orig.)

  1. Rheometric research of polypropylene Licocene PP2602 melts

    Directory of Open Access Journals (Sweden)

    V.V. Romanuke

    2011-07-01

    Full Text Available Purpose: To comprehend and ascertain reasons of the transition into the non-Newtonian viscosity zone for the melted polypropylene material, depending upon the number of recycling series.Design/methodology/approach: There were carried researches on rheological features of the primary material of the melted polypropylene Licocene PP2602, subjected to be processed repeatedly in as many series as needed, using the Brookfield viscometer CAP2000+ within the temperature range 130-200ºC and the shear rate range 166-3000 s–1.Findings: There were obtained dependence of polypropylene melt viscosity against the shear rate at fixed temperatures, and dependence of polypropylene melt shear stress against the shear rate at fixed temperatures with the non-Newtonian viscosity transient zone shifting into the zone of greater shear rate values as the temperature increases. Also there was obtained dependence of the shear stress critical value on the number of recycling series, where the corresponding critical shear rate value grows as this number increases. This may be applied for predetermining the state of the repeatedly processed polymer material.Research limitations/implications: The found rheometric regularities reflect behaviour for a homologous series of the polymer, but most probably they are generic for all polyolefines, what should be investigated and ascertained subsequently.Practical implications: On the ground of the ascertained temperature-rate dependences of the polypropylene melt flow, there has appeared a possibility to gain a quantitative response about the secondary low-density-polyethylene material state, what allows selecting strategically the way of controlling this material properties, and that let develop new composites of those recycled materials for manufacturing footwear at enterprise “Vzuteks” (Khmelnytskyy.Originality/value: The present paper states that processing the polymer materials repeatedly influences directly on their rheological parameters, increasing, particularly, the melt shear rate critical value.

  2. Evaluation of healing prosthetic materials polyester mesh resorbable film and collagen elastin matrix /polypropylene used in rabbits abdominal wall defects Avaliação da cicatrização da tela de poliéster com lâmina absorvível e a tela de colágeno-elastina/polipropileno utilizadas no reparo de lesões da parede abdominal de coelhos

    OpenAIRE

    Danielle Duck Schulz; Nicolau Gregori Czeczko; Osvado Malafaia; Gustavo Justo Schulz; Leticia Elizabeth A. Czeczko; Larissa Santin Garcia; Ulrich Andreas Dietz

    2009-01-01

    PURPOSE: To compare polyester with absorbable layer prosthesis with collagen-elastin/polypropylene prosthesis in the repair of abdominal wall defects. METHODS: The 16 studied rabbits were divided in groups A and B (euthanized on the 30th and 60th days, after the implant of the mesh). The animals underwent laparotomy and received a 2cm wall "defect" on each side of the Alba linea. The repair was made with the suture of a polyester mesh with absorbable film on the left side of the Alba Linea an...

  3. Later reproductive health after B-Lynch sutures : a follow-up study after 10 years' clinical use of the B-Lynch suture

    DEFF Research Database (Denmark)

    Fuglsang, Jens

    2014-01-01

    OBJECTIVE: To evaluate the reproductive prognosis after having a B-Lynch suture placed previously. DESIGN: Follow-up study based on patients' records. SETTING: University hospital setting (level three; 4,800 deliveries per year). PATIENT(S): All patients registered to have had a B-Lynch suture placed from 2002 to 2012. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Future pregnancies. RESULT(S): Forty-four B-Lynch procedures were identified in 43 women. Twenty-six were primiparas at the time of B-Lynch suture. Follow-up took place a median 45 months (range, 17-126 months) after B-Lynch suture placement; one woman was lost to follow-up. Overall, 16 of 42 women obtained a new pregnancy. Among primiparas, 44% either had an ongoing pregnancy or a delivery. Among women not having a succeeding pregnancy, one woman had a peripartum hysterectomy, one was advised against pregnancy, one developed Asherman's syndrome, and three women were known to attempt to obtain pregnancy. In deliveries after a previous B-Lynch suture, 3 of 13 women had estimated bleeding above 1,000 mL, and 2 of these had severe bleeding. A time trend was observed indicating that B-Lynch sutures are placed increasingly often. CONCLUSION(S): The reproductive prognosis after a B-Lynch suture has been placed seems to be relatively good. Nonetheless, complications that might influence future pregnancy may occur, and advice given should address this.

  4. A Comparative In Vivo Study of Tissue Reactions to Four Suturing Materials

    Directory of Open Access Journals (Sweden)

    Shahla Kakoei

    2010-06-01

    Full Text Available INTRODUCTION: The purpose of this study was to compare the histopathologic reaction of four suturing materials: silk, polyvinylidene fluoride (PVDF, polyglycolic acid, and catgut in the oral mucosa of albino rabbits. MATERIALS AND METHODS: The twenty-one male mature albino rabbits which were used in this study were randomly divided into three groups of seven each. Silk, PVDF, polyglycolic acid and catgut suture materials were tested in the oral mucosa of these animals. The animals were sacrificed 2, 4, and 7 days after suturing. Two pathologists evaluated the samples by determining the presence and level of inflammation, granulation tissue, and fibrosis formation. Data were statistically analyzed by Kruskal Wallis and Mann-Whitney U tests. RESULTS: Histological features of the samples showed that PVDF and plain catgut suture materials produced more fibrous tissue (favorable response on the fourth day in comparison with silk suture (P=0.02. Also, in the 7-day samples PVDF sutures produced the mildest inflammation when compared with the silk sutures (P=0.015. CONCLUSION: According to the results of this study, it can be convey that PVDF suture materials created mild tissue reactions and can be a reasonable candidate for suturing oral tissues.

  5. 21 CFR 878.4493 - Absorbable poly(glycolide/l-lactide) surgical suture.

    Science.gov (United States)

    2010-04-01

    ... device is FDA's “Class II Special Controls Guidance Document: Surgical Sutures; Guidance for Industry and... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices §...

  6. Follow up CT findings of suture granuloma in the chest wall: A case report

    International Nuclear Information System (INIS)

    Suture granuloma is a benign tumor defined by an inflammatory reaction and the formation of granuloma, which is caused by the reaction of a foreign body in regards to suture material after surgery. Recently, it has been reported as one of the rare complications following surgery, mainly in regards to non absorbable sutures. The authors hereby report a case along with CT findings and literature review for suture granuloma in the chest wall after lung lobectomy for lung cancer in a 65 year old woman

  7. Recent advances in biodegradable metals for medical sutures: a critical review.

    Science.gov (United States)

    Seitz, Jan-Marten; Durisin, Martin; Goldman, Jeremy; Drelich, Jaroslaw W

    2015-09-16

    Sutures that biodegrade and dissolve over a period of several weeks are in great demand to stitch wounds and surgical incisions. These new materials are receiving increased acceptance across surgical procedures whenever permanent sutures and long-term care are not needed. Unfortunately, both inflammatory responses and adverse local tissue reactions in the close-to-stitching environment are often reported for biodegradable polymeric sutures currently used by the medical community. While bioabsorbable metals are predominantly investigated and tested for vascular stent or osteosynthesis applications, they also appear to possess adequate bio-compatibility, mechanical properties, and corrosion stability to replace biodegradable polymeric sutures. In this Review, biodegradable alloys made of iron, magnesium, and zinc are critically evaluated as potential materials for the manufacturing of soft and hard tissue sutures. In the case of soft tissue closing and stitching, these metals have to compete against currently available degradable polymers. In the case of hard tissue closing and stitching, biodegradable sternal wires could replace the permanent sutures made of stainless steel or titanium alloys. This Review discusses the specific materials and degradation properties required by all suture materials, summarizes current suture testing protocols and provides a well-grounded direction for the potential future development of biodegradable metal based sutures. PMID:26172399

  8. Ureteroscopic holmium laser cutting for inadvertently sutured drainage tube (report of five cases).

    Science.gov (United States)

    Gao, Xu; Lu, Xin; Ren, Shancheng; Xu, Chuanliang; Sun, Yinghao

    2008-07-01

    The aim of this paper is to report a simple solution for inadvertently sutured drainage tube after urological surgery and discuss the different managements according to different types of this embarrassing complication. From September 2001 to January 2007, five inadvertently sutured drainage tubes were treated with ureteroscopic holmium laser cutting for the suture. All drainage tubes were removed after the operation without other complications. Holmium laser cutting via ureteroscope is a simple solution for the embarrassing problem of inadvertently sutured drainage tube. It can save the patient from undergoing another open surgery. PMID:17713824

  9. HISTOPATHOLOGICAL EVALUATION OF TWO SUTURING TECHNIQUES FOR END-TO-END ANASTOMOSIS OF COLON OF DOGS

    OpenAIRE

    A.B. Kachiwal and A.B. Kalhoro

    2003-01-01

    An experimental study was conducted on 12 healthy adult dogs to determine the best method for anastomosis of colon. An appositional 2 layer (APP-2) suture pattern was compared with the inverting 2 layer (INV-2) suture pattern for end-to-end anastomosis. VicrylR (size 3-0) was used for anastomosis. At day 10 after surgery, all anastomotic lines were apposed but the mucosa did not cover the lumen of the anastomosis with APP-2 layer suture pattern. The specimens closed w1th INV-2 layer suture pa...

  10. Impaired Posterior Frontal Sutural Fusion in the Biglycan/Decorin Double Deficient Mice

    OpenAIRE

    Wadhwa, Sunil; Bi, Yanming; Ortiz, Ana T.; Embree, Mildred C.; Kilts, Tina; Iozzo, Renato; Opperman, Lynne A.; Young, Marian F.

    2006-01-01

    Biglycan (Bgn) and decorin (Dcn) are highly expressed in numerous tissues in the craniofacial complex. However, their expression and function in the cranial sutures is unknown. In order to study this, we first examined the expression of biglycan and decorin in the posterior frontal suture (PFS), which predictably fuses between 21–45 days post-natal and in the non-fusing sagittal (S) suture from wildtype (Wt) mice. Our data showed that Bgn and Dcn were expressed in both cranial sutures. We the...

  11. Evaluation of surgical implantation of electronic tags in European eel and effects of different suture materials

    DEFF Research Database (Denmark)

    Thorstad, Eva B.; Økland, Finn

    2013-01-01

    Effects of implanting data-storage tags in European eel, Anguilla anguilla, and the suitability of different suture materials (braided permanent silk, permanent monofilament, absorbable and absorbable antibacterial) were examined. The tags consisted of an electronic unit and three floats on a wire, making them flexible and able to follow the swimming movements of the eel. No mortality occurred, and tagged fish did not differ from the control fish in growth. Sutures were shed or dissolved slowly. After 4 weeks, there was no difference among the groups in the proportion of sutures left. After 6 months, fish with braided silk had largely shed their sutures, fish with monofilament sutures had the majority of sutures left, whereas the fish with absorbable sutures were intermediate in between. Fish with monofilament sutures showed the least-extensive inflammation reactions and fastest wound healing. Antibacterial treatment had no effect on inflammation or healing rates. After 6 months, the tag started to become expelled through the incision in five fish (12%). The internal reaction appeared stronger around the floats, suggesting that the coating material of the floats created a tissue reaction, which should be further investigated. Intraperitoneal implantation appears to be a suitable tagging method for European silver eel, and it is recommended to close incisions using permanent monofilament sutures

  12. Follow up CT findings of suture granuloma in the chest wall: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ka Eun; Lee, Young Kyung [Kyung Hee Univ. Hospital at Gangdong/School of Medicine/Kyung Hee Univ. Seoul, (Korea, Republic of); Sung, Dong Wook [Kyung Hee Univ. Hospital/School of Medicine/Kyung Hee Univ., Seoul, (Korea, Republic of)

    2012-09-15

    Suture granuloma is a benign tumor defined by an inflammatory reaction and the formation of granuloma, which is caused by the reaction of a foreign body in regards to suture material after surgery. Recently, it has been reported as one of the rare complications following surgery, mainly in regards to non absorbable sutures. The authors hereby report a case along with CT findings and literature review for suture granuloma in the chest wall after lung lobectomy for lung cancer in a 65 year old woman.

  13. Morphological Study of Vault Suture AND Its Correlation with Age in Central Rajasthan

    OpenAIRE

    William F Masih; Sumit Gupta; Pratima Jaiswal; Anita E Chand; Pramod Kumar Saraswat

    2014-01-01

    Introduction: The suture closure of skull has a time and sequence of their union and study of suture closure can be correlated to its age and the obliteration of sutures is affected by sex, race, climate, heredity and diet Aims: To study the closure of vault sutures on both inner and outer surface of skull and its correlation with age. Methods: Total 200 skulls in autopsy cases (157 males and 43 females) from all age groups were studied. Results: In males the minimal age of fusion i...

  14. Extrusion of bone anchor suture following flexor digitorum profundus tendon avulsion injury repair.

    LENUS (Irish Health Repository)

    Tiong, William H C

    2011-09-01

    Flexor digitorum profundus (FDP) zone I tendon avulsion injury is traditionally repaired with a pullout suture technique. More recently, bone anchor sutures have been used as a viable alternative and have largely replaced areas in hand surgery where pullout suture technique was once required. To date, there have been very few complications reported related to bone anchor suture use in FDP tendon reattachment to the bone. We report a very unusual case of extrusion of bone anchor through the nailbed, 6 years after zone I FDP tendon avulsion injury repair and a brief review of literature.

  15. Clinical Results of Meniscal Repair Using Submeniscal Horizontal Sutures

    Directory of Open Access Journals (Sweden)

    Amir Mohammad Navali

    2015-07-01

    Full Text Available Background:  Parts of the implants placed over the meniscus during meniscal repair can wear down the cartilage in the contact zones and cause chronic synovitis. Placing horizontal sutures under the meniscus may overcome this potential hazard. The purpose of this prospective study was to evaluate the midterm results of arthroscopic meniscal repair using submeniscally placed out-in horizontal sutures.  Methods:  One hundred and three meniscal repairs with submeniscal horizontal out-in technique in 103 patients were performed between 2009 and 2012. Our indications for meniscal repair were all longitudinal tear in red-red and redwhite zone with acceptable tissue quality. Clinical evaluation included the Tegner and Lysholm knee scores and clinical success was defined as absence of joint-line tenderness, locking, swelling, and a negative McMurray test. Results:  The average follow-up was 19 months (range, 14 to 40 months. The time interval from injury to meniscal repair ranged from 2 days to 390 days (median, 96 days. At the end of follow-up, the clinical success rate was 86.5%.  Fourteen of 103 repaired menisci (13.5% were considered failures according to Barrett’s criteria. The mean Lysholm score significantly improved from 39.6 preoperatively to 84.5 postoperatively (P?0.001. Eighty five patients (82.5% had an excellent or good result according to Lysholm knee score. Tegner activity score improved significantly (P?0.01 from an average of 3.4 (range, 2-6 preoperatively to 5.9 (range, 5-8 postoperatively. Statistical analysis showed that age, simultaneous anterior cruciate ligament reconstruction, chronicity of injury did not affect the clinical outcome.  Conclusion:  Our results showed that acceptable midterm results are expected from submeniscal horizontal out-in repair technique. This technique is cheap, safe and has the advantage of avoiding chondral abrasion caused by solid implants and suture materials placed over the meniscus.

  16. 2-hydroxyethyl methacrylate composite - polypropylene mesh for preventing peritoneal adhesions in female dogs Compósito 2-hidroxietil dimetacrilato-tela de polipropileno para prevenção de aderências peritoneais em cadelas

    Directory of Open Access Journals (Sweden)

    Marcelo Seixo de Brito e Silva

    2010-08-01

    Full Text Available PURPOSE: To evaluate whether the lining facing the visceral side of polypropylene mesh made with 2-hydroxyethyl methacrylate (p(HEMA hydrogel could avoid peritoneal adhesion in female dogs. METHODS: Eight animals (group PP had a polypropylene mesh implanted to correct a defect in the rectal abdominal muscle, whereas in the other group (group PH the polypropylene mesh was coated with p(HEMA composite on the surface facing the peritoneal area. RESULTS: Adhesions were observed on the mesh in 62.5% of the PP group. In the PH group adhesions were present only on the suture lines. CONCLUSION: p(HEMA hydrogel was well tolerated and effective in avoiding visceral and omental adhesions on the surface of the polypropylene mesh.OBJETIVO: Avaliar se o revestimento da face visceral de uma tela de polipropileno com 2-hidroxietil dimetacrilato (p(HEMA poderia evitar aderências peritoniais em cadelas. MÉTODOS: Em oito animais (Grupo PP foram implantadas telas de polipropileno para correção de um defeito do músculo reto abdominal, enquanto em outro grupo (Grupo PH fez-se a implantação de uma tela de polipropileno cuja face peritonial foi revestida por 2-hidroxietil dimetacrilato (p(HEMA. RESULTADOS: Foram observados 62,5% de aderências peritoniais sobre a tela nos animais do Grupo PP, enquanto que no Grupo PH estas não ocorreram, exceto sobre a linha se sutura. CONCLUSÃO: O hidrogel de p(HEMA foi bem tolerado pelos animais e mostrou-se efetivo na prevenção das aderências viscerais e omentais sobre a tela de polipropileno.

  17. Effectivity of intraoperative adjustable suture technique in horizontal strabismus

    Directory of Open Access Journals (Sweden)

    Ayse Gul Kocak Altintas

    2013-08-01

    Full Text Available AIM:To compare the long-term effectivity of intraoperative adjustable suture technique with traditional non-adjustable strabismus surgery.METHODS:Two hundred and thirty-three patients, who underwent strabismus surgery either with traditional procedures or one-stage intraoperative adjustable suture technique, were included in our long-term follow-up study. One hundred and eighteen patients were evaluated in traditional surgery group (TSG and 115 who underwent adjustable suture were in the one-stage intraoperative adjustable surgery group (ASG. In this group 9 patients had paralytic strabismus and 16 had reoperations, 2 patients had restrictive strabismus related to thyroid eye disease. The mean follow up in the TSG was 26.2 months and it was 24.8 months in the ASG group.RESULTS:In patients with exotropia (XT the mean correction of deviation for near fixation in ASG (32.4±13.2PD and in TSG (26.4±8.2PD were similar (P=0.112. The correction for distant fixation in ASG (33.2±11.4PD and TSG (30.9±7.2PD were not significantly different (P=0.321. In patients with esotropia (ET even the mean correction of deviation for both near (31±12PD and distant (30.6±12.8PD fixations were higher in ASG than in TSG, for both near (28.27±14.2PD and distant (28.9±12.9PD fixations, the differences were not significant (P=0.346, 0.824 respectively. The overall success rate of XT patient was 78.9% in TSG and 78.78% in ASG, the difference was not significant (P=0.629. The success rates were 78.75% in TSG and 75.51% in ASG in ET patient, which was also not significantly different (P=0.821.CONCLUSION:Although patients in ASG had more complex deviation such as paralysis, reoperations and restrictive strabismus, success rates of this tecnique was as high as TSG which did not contain complicated deviation. One-stage intraoperative adjustable suture technique is a safe and effective method for cooperative patient who has complex deviation.

  18. Sacrospinous Ligament Fixation Simplified with a New Endoscopic Suturing Device

    Science.gov (United States)

    Papasakelariou

    1996-08-01

    This study evaluated the effectiveness of the EndoStitch during sacrospinous ligament fixation in 28 women, in combination with correction of other pelvic floor disorders. Application and retrieval of Surgidac (a coated and braided polyester suture) were performed in under 5 minutes without any complications. The patients were followed in terms of vaginal vault support, vaginal length, vaginal axis deviation, sexual discomfort when applicable, and bladder or rectal dysfunction. There was one failure. The technique was easy, safe, and easy to teach. PMID:9074209

  19. Iris mattress suture: a technique for sectoral iris defect repair.

    Science.gov (United States)

    Tsao, Sean W; Holz, Huck A

    2015-03-01

    Achieving a cosmetic and functional outcome from iris defect repair is a surgical challenge. We describe an adaptation of techniques to address a case of 2.5 clock hours of sectoral iris tissue defect. Our method combines Siepser's modified closed-chamber sliding knot technique with the placement of a double-armed iris mattress suture to approximate iris tissue to the scleral wall and thereby create a pseudo-iris root. This technique reduces glare and achieves a cosmetic outcome for the patient. PMID:24879808

  20. Development of foams from linear polypropylene (PP) and high melt strength polypropylene (HMSPP) polymeric blends

    International Nuclear Information System (INIS)

    Foamed polymers are future materials, with a comprehensive application field. They can be used in order to improve appearance of insulation structures, for example, or to reduce costs involving materials. This work address to Isotactic Polypropylene / High Melt Strength Polypropylene blends, for foams production. Rheological behavior of polymer melt, especially referring to viscosity in processing temperature, plays a decisive role in applications where dominates extensional flow, as in case of foaming. If the viscosity is very low, it will correspond to a low melt strength, as in case of linear homopolymer (Isotact PP), and the foam will be prejudiced, due to the impossibility of expansion. Otherwise, if the viscosity is very high, with a high melt strength, the foam will collapse immediately after its formation. In order to get foams with an homogeneous and defined cellular structure, there were accomplished blends, 50% in weight, between linear homopolymer (isotactic PP) and HMSPP, from PP modified as per gamma radiation, in acetylene environment and at a 12.5 kGy doses. Extrusion process used a soluble foaming methodology, according to a processing/dissolution principle, which involves the dissolution of a Physical Blowing Agent (PBA), under 30 bar pressure, homogeneously mixed with polymeric melt. Extrusion conditions, that generally involve temperature, pressure and viscoelastic material flow control were experimentally investigated to define prevalent characteristics for producing foams. Nitrogen was the used PBA and process extrusion parameters were adapted to PP, HMSPP and their 50% in weight mixtures thereof. Major PP and HMSPP characteristics were obtained via melt Index and melt strength and thermal analyses (DSC/TGA), in order to make viable and to reproduce foaming as per extrusion process. Foams cellular morphology of PP, HMSPP and their 50% in weight mixtures thereof was investigated, with and without talc addition, as nucleating agent, by using Scanning Electron Microscope (SEM). Micrographs obtained pointed to closed cells foams, in which the pressure is kept during all cell formation stage, informing that closed cells foams are used in thermal insulation in Civil Construction and in thermal vials. Density analyses accomplished in foams produced in our work showed typical results for high density foams (320 to 800 kg/m3 range), around 500 kg/m3, used for wire and cables and for structural purposes (structural foams), by replacing wood, metals or solid plastics. Structural foams have high density (above 320 kg/m3) and cellular structures are specially composed by holes. (author)

  1. Antibacterial Surgical Silk Sutures Using a High-Performance Slow-Release Carrier Coating System.

    Science.gov (United States)

    Chen, Xiaojie; Hou, Dandan; Wang, Lu; Zhang, Qian; Zou, Jiahan; Sun, Gang

    2015-10-14

    Sutures are a vital part for surgical operation, and suture-associated surgical site infections are an important issue of postoperative care. Antibacterial sutures have been proved to reduce challenging complications caused by bacterial infections. In recent decades, triclosan-free sutures have been on their way to commercialization. Alternative antibacterial substances are becoming relevant to processing surgical suture materials. Most of the antibacterial substances are loaded directly on sutures by dipping or coating methods. The aim of this study was to optimize novel antibacterial braided silk sutures based on levofloxacin hydrochloride and poly(?-caprolactone) by two different processing sequences, to achieve suture materials with slow-release antibacterial efficacy and ideal physical and handling properties. Silk strands were processed into sutures on a circular braiding machine, and antibacterial treatment was introduced alternatively before or after braiding by two-dipping-two-rolling method (M1 group and M2 group). The antibacterial activity and durability against Staphylococcus aureus and Escherichia coli were tested. Drug release profiles were measured in phosphate buffer with different pH values, and release kinetics model was built to analyze the sustained drug release mechanism between the interface of biomaterials and the in vitro aqueous environment. Knot-pull tensile strength, thread-to-thread friction, and bending stiffness were determined to evaluate physical and handling properties of sutures. All coated sutures showed continuous antibacterial efficacy and slow drug release features for more than 5 days. Besides, treated sutures fulfilled U.S. Pharmacopoeia required knot-pull tensile strength. The thread-to-thread friction and bending stiffness for the M1 group changed slightly when compared with those of uncoated ones. However, physical and handling characteristics of the M2 group tend to approach those of monofilament ones. The novel suture showed acceptable in vitro cytotoxicity according to ISO 10993-5. Generally speaking, all coated sutures show potential in acting as antibacterial suture materials, and M1 group is proved to have a higher prospect for clinical applications. PMID:26378964

  2. Polypropylene/Graphene and Polypropylene/Carbon Fiber Conductive Composites: Mechanical, Crystallization and Electromagnetic Properties

    Directory of Open Access Journals (Sweden)

    Chien-Lin Huang

    2015-11-01

    Full Text Available This study aims to examine the properties of composites that different carbon materials with different measurements can reinforce. Using a melt compounding method, this study combines polypropylene (PP and graphene nano-sheets (GNs or carbon fiber (CF to make PP/GNs and PP/CF conductive composites, respectively. The DSC results and optical microscopic observation show that both GNs and CF enable PP to crystalize at a high temperature. The tensile modulus of PP/GNs and PP/CF conductive composites remarkably increases as a result of the increasing content of conductive fillers. The tensile strength of the PP/GNs conductive composites is inversely proportional to the loading level of GNs. Containing 20 wt% of GNs, the PP/GNs conductive composites have an optimal conductivity of 0.36 S/m and an optimal EMI SE of 13 dB. PP/CF conductive composites have an optimal conductivity of 10?6 S/m when composed of no less than 3 wt% of CF, and an optimal EMI SE of 25 dB when composed of 20 wt% of CF.

  3. Effect of maleated polypropylene emulsion on the mechanical and thermal properties of lignin-polypropylene blends

    Science.gov (United States)

    Abdelwahab, Mohamed; Misra, Manjusri; Mohanty, Amar

    2015-05-01

    The increasing oil rates and environmental concerns of the use of synthetic or petroleum-based polymers has newly led to a growing attention in eco-friendly materials. Lignin has received much attention as a novel eco-friendly material due to its abundant availability and its potential as a low-cost filler. Biobased blends from polypropylene (PP) and lignin were fabricated by extrusion followed by injection moulding. In order to improve the compatibility of the polar lignin and the non-polar matrix PP, three different maleated PP emulsions, namely ME91735 (nonionic PP emulsion), ME42035 (cationic water based emulsion of polyolefin waxes) and PP286 (containing 1-5% N,N-ethylethanolamine) were used as coupling agents. The mechanical properties such as tensile and flexural strength as well as tensile and flexural modulus of the blends were improved by using lignin treated with 2.5 wt.% of the emulsions. However, the elongation at break decreased in the case of the lignin treated with ME91735 and ME42035 as compared to the untreated lignin. The morphological and thermal properties of the blends were also studied.

  4. New insights into the relationship between suture closure and craniofacial dysmorphology in sagittal nonsyndromic craniosynostosis.

    Science.gov (United States)

    Heuzé, Yann; Boyadjiev, Simeon A; Marsh, Jeffrey L; Kane, Alex A; Cherkez, Elijah; Boggan, James E; Richtsmeier, Joan T

    2010-08-01

    Premature closure of the sagittal suture occurs as an isolated (nonsyndromic) birth defect or as a syndromic anomaly in combination with other congenital dysmorphologies. The genetic causes of sagittal nonsyndromic craniosynostosis (NSC) remain unknown. Although variation of the dysmorphic (scaphocephaly) skull shape of sagittal NSC cases has been acknowledged, this variation has not been quantitatively studied three-dimensionally (3D). We have analyzed the computed tomography skull images of 43 infants (aged 0.9-9 months) with sagittal NSC using anatomical landmarks and semilandmarks to quantify and characterize the within-sample phenotypic variation. Suture closure patterns were defined by dividing the sagittal suture into three sections (anterior, central, posterior) and coding each section as 'closed' or 'fused'. Principal components analysis of the Procrustes shape coordinates representing the skull shape of 43 cases of NSC did not separate individuals by sex, chronological age, or dental stages of the deciduous maxillary first molar. However, analysis of suture closure pattern allowed separation of these data. The central section of the sagittal suture appears to be the first to fuse. Then, at least two different developmental paths towards complete fusion of the sagittal suture exist; either the anterior section or the posterior section is the second to fuse. Results indicate that according to the sequence of sagittal suture closure patterns, different craniofacial complex shapes are observed. The relationship between craniofacial shape and suture closure indicates not only which suture fused prematurely (in our case the sagittal suture), but also the pattern of the suture closure. Whether these patterns indicate differences in etiology cannot be determined with our data and requires analysis of longitudinal data, most appropriately of animal models where prenatal conditions can be monitored. PMID:20572900

  5. A biodegradable button to augment suture attachment in rotator cuff repair.

    Science.gov (United States)

    Bravman, Jonathan T; Guttman, Dan; Rokito, Andrew S; Kummer, Frederick J; Jazrawi, Laith M

    2006-01-01

    Recent experimental studies suggest that the use of suture anchors for rotator cuff tear (RCT) repair transfers the "weak link" to the suture-tendon interface where failure occurs as the sutures cut through the tendon. The purpose of this study was to evaluate the effect of using a suture augmentation button on the fixation strength of rotator cuff tendon repair. A 1.5 cm by 2 cm defect was created in the supraspinatus tendon of seven cadaveric shoulder pairs and two suture anchors inserted in each humerus for suture attachment. For one of each pair, the defect was repaired with sutures placed in a horizontal mattress configuration. The other side was repaired with the sutures being passed through low profile, bioabsorbable buttons placed on the bursal tendon surface prior to knot tying. The supraspinatus tendon was cyclically loaded at a physiologic rate and load (33 mm/sec and 180 N, respectively). The number of loading cycles was recorded when the specimens developed 0.75 cm and 1.5 cm gaps at the repair site. The specimens were then tested to failure. Specimens in the unaugmented group developed 0.75 cm and 1.5 cm gaps at an average of 135 cycles and 362 cycles, respectively. The button augmented group developed these gaps at average of 420 cycles and 708 cycles, respectively. These differences were statistically significant (p < 0.05). The gaps progressively increased in all specimens, which eventually failed by suture cutting through tendon in all specimens. This study demonstrates that in vitro, suture augmentation with a low profile, bioabsorbable button provides significantly enhanced fixation when using suture anchors to repair torn rotator cuff tendon. This device may be a useful adjunct to current methods of rotator cuff repair. PMID:16878833

  6. Suture of a stab wound of the heart.

    Science.gov (United States)

    Ellis, Harold

    2015-01-01

    Over many centuries, from the early writings of Galen, 'the father of Medicine', wounds of the heart were considered fatal and outside the remit of surgery. With the advent of anaesthesia, (ether was introduced by William Morton in 1846) and of antiseptic surgery, (Joseph Lister's first publication was in 1867), there was an explosion in the surgery of the abdominal cavity, the chest, the skull and the limbs, yet the heart was considered by the surgical fraternity to be the 'no-go' area of the body. Theodor Billroth, Professor of Surgery in Vienna and himself a pioneer of modern surgery, (he performed the first successful partial gastrectomy for carcinoma of the stomach in 1881), wrote "the surgeon who would attempt to suture a wound of the heart should lose the respect of his colleagues". In London, Stephen Paget, in 1896, wrote: "No new method and no new discovery can overcome the natural difficulties that attend a wound of the heart. It is true that suture has been vaguely proposed as a possible procedure and has been done in animals but I cannot find that it has ever been attempted in practice". (In fact, the heart is an amazingly tough and efficient pump that goes on working, year after year, without ever stopping for a service!). PMID:26309960

  7. An experimental model to retraining in microvascular suture

    Scientific Electronic Library Online (English)

    Marcos Ricardo de Oliveira, Jaeger; Pedro Bins, Ely; Jefferson André, Pires; Lydia Masako, Ferreira.

    Full Text Available PURPOSE: To demonstrate an experimental model of up to four hours a week of independent study that allows relearning in microvascular sutures. METHODS: Wistar rats between 200 and 500 grams surplus research experiments were used. Femoral vessels are covered on one or both sides through a groin i [...] ncision obliquely along the inguinal ligament. Femoral artery and vein are isolated and measured being clamped and cut. The individual performs in microvascular anastomosis complexity arterial and venous terminoterminal sequence. terminolateral and venous and arterial grafts in vessels. Permeability is evaluated by testing vascular patency after creation of microvascular anastomosis. RESULTS: In the first specimen, only arterial and venous vascular anastomosis are performed terminoterminal. The average diameter of the femoral veins varies from 0.8 to 2 mm between rodents (artery, between 0.6 and 1.4 mm, between 0.8 and 2 mm vein). The superficiality of the vessels allows faster dissection, may also be held in other inguinal region. CONCLUSION: The model of individual retraining allows learning microvascular suture in individuals of permanent staff.

  8. Revisiting the Variscan transpressional tectonics in the Southwestern Iberian suture

    Science.gov (United States)

    Pérez Cáceres, Irene; Martínez Poyatos, David; Simancas, José Fernando; Azor, Antonio

    2014-05-01

    The boundary between the Ossa-Morena Zone (OMZ) and the South Portuguese Zone (SPZ) in southwest Iberia is a Variscan collisional suture with transpressive left-lateral kinematics, contrasting with the dextral component that characterizes most of the Variscan convergence in other regions of the Orogen. Recent work including new structural and radiometric data has improved our knowledge on the geometry and timing of deformations affecting the OMZ/SPZ suture, which can be summarized as follows: Closure of the Rheic Ocean in Late Devonian time is attested by high-pressure and ophiolitic thin allochthonous units emplaced on the southern border of the OMZ. The kinematic interpretation of early stretching lineations and tectonic fabrics indicate that these units were emplaced in a tectonic regime of oblique left-lateral convergence. Transient transtension in Early Carboniferous time gave way to a narrow aisle of newly-formed oceanic-like crust just over the foregoing Rheic Ocean suture, accompanied by mafic magmatism intruded/extruded at both continental sides. Radiometric dating has yielded the same age of around 340 Ma for the oceanic-like mafic protholiths and their granulite/amphibolite facies tectonic fabric, thus indicating the very ephemeral life of the oceanic-like strip. Oblique convergence was resumed immediately after transtension, first causing northward obduction of the oceanic-like unit and north-verging folding in metasedimentary units of the southern border of the suture. Later on, a south-vergent regional fold was developed synchronous with left-lateral granulite-amphibolite facies shearing. Finally, shear deformation gave way to a low pitch stretching lineation, thrusting the OMZ over SPZ, concentrated on the southern limb of this regional fold and constituting a complex ductile 2-3 km-thick shear band evolving from amphibolite to greenschist facies, developing: (i) high-temperature greenschists at the southern border of the mafic oceanic-like unit, which propagated southwards progressively cooling to low-temperature greenschists; (ii) disruption of layers that produced small fishes of weakly deformed rocks, previously interpreted as sedimentary mélanges. Radiometric dating of acid volcanic rocks included in the low-grade shear zone has yielded an age of 337 Ma, putting an older limit to shearing. At late Variscan time, a brittle left-lateral shear band partially obliterated the previous syn-metamorphic shear zone. Oblique convergence propagated southwards across the SPZ in Late Carboniferous time, though lateral displacements decreased rapidly in favor of shortening. This deformation has been roughly modelled as a transpressional band characterized by 40% shortening and ?=1 shearing. An age of 330 Ma yielded by a deformed granite at the northern part of the SPZ probably indicates the arrival of deformation at that point, while stratigraphic data suggest that deformation reached SW Portugal at around 310 Ma. To conclude, the transpressive OMZ/SPZ boundary shows strain partitioning, with left-lateral displacements concentrated in ductile to brittle shear zones affecting the suture units, and moderately oblique shortening affecting a broad zone of the SPZ foreland.

  9. Stress and strain analysis on the anastomosis site sutured with either epineurial or perineurial sutures after simulation of sciatic nerve injury?

    OpenAIRE

    Liu, Guangyao; Zhang, Qiao; Jin, Yan; Gao, Zhongli

    2012-01-01

    The magnitude of tensile stress and tensile strain at an anastomosis site under physiological stress is an important factor for the success of anastomosis following suturing in peripheral nerve injury treatment. Sciatic nerves from fresh adult cadavers were used to create models of sciatic nerve injury. The denervated specimens underwent epineurial and perineurial suturing. The elastic modulus (40.96 ± 2.59 MPa) and Poisson ratio (0.37 ± 0.02) of the normal sciatic nerve were measured by stra...

  10. 21 CFR 878.5000 - Nonabsorbable poly(ethylene terephthalate) surgical suture.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonabsorbable poly(ethylene terephthalate... Devices § 878.5000 Nonabsorbable poly(ethylene terephthalate) surgical suture. (a) Identification. Nonabsorbable poly(ethylene terephthalate) surgical suture is a multifilament, nonabsorbable, sterile,...

  11. Early secondary suture versus healing by second intention of incisional abscesses

    DEFF Research Database (Denmark)

    Hermann, G G; Bagi, P; Christoffersen, I

    1988-01-01

    A controlled trial was set up to compare the treatment of wound abscesses, occurring after laparotomy, with either early secondary suture combined with cefuroxime and metronidazole given intravenously or by healing by second intention. The secondary suture was performed two days after wound...

  12. Arthroscopic repair of peripheral triangular fibrocartilage complex tears with suture welding: a technical report.

    Science.gov (United States)

    Badia, Alejandro; Jiménez, Alexis

    2006-10-01

    This report presents a method of arthroscopic repair of the peripheral triangular fibrocartilage complex tears that replaces traditional suture knots with ultrasonic welding of sutures. This will help eliminate potential causes of ulnar-sided wrist discomfort during the postoperative period. PMID:17027791

  13. Preliminary calculations of coolant flow in a SCWR Fuel assembly with the code ANSYS CFX 10.0

    International Nuclear Information System (INIS)

    For the design of Supercritical-Water Cooled Reactors (SCWRs) it is important to get know the thermal phenomena and the flow field in the different fuel assembly concepts. The ANSYS-CFX-10.0 code, a commercial computational fluid dynamics code has been used for investigating this field. The specific feature of the supercritical heat transfer is that the material properties change dramatically in a specific temperature range around the so-called pseudo-critical temperature. Because of this specific feature, we had to validate the ANSYS-CFX-10.0 code to see if it is capable for handling the heat transfer phenomena for supercritical state fluids. The calculations of a 2950 mm long straight pipe model were compared with measurement data and the prediction of the Swenson correlation recommended by international literature. The validation has been successful and the study could keep on. Three different sub-channel models were developed based on the European SCWR fuel assembly concept. Several calculations were performed with these sub-channel models for different boundary conditions. The calculations performed have showed problems with imbalance values. This investigation has showed the difficulty of the calculation of heat transfer processes when the temperature is around the value of the pseudo-critical temperature

  14. Surface characterization of plasma-treated polypropylene fibers

    International Nuclear Information System (INIS)

    Plasma treatment is increasingly being used for surface modification of different materials in many industries. In this study, different techniques were employed to characterize the surface properties of plasma treated polypropylene fibers. The chemical nature of the fiber sufaces has been investigated by X-ray photoelectron spectroscopy (XPS). The XPS examination indicated the presence of oxygen-containing functional groups on fiber surfaces after plasma treatment. The Atomic Force Microscopy (AFM) scans revealed the evolution of surface morphology under different experimental conditions. A Philips Environmental Scanning Electron Microscopy (ESEM) was also used to study the wetting behavior of the fibers. In the ESEM, relative humidity can be raised to 100% to facilitate the water condensation onto fiber surfaces for wetting observation. The ESEM observation revealed that the plasma treatment significantly altered the surface wettability of polypropylene fibers

  15. DSC Study on Polypropylene Modified with Calcium Carbonate Nanoparticles

    International Nuclear Information System (INIS)

    The exposure of polypropylene containing various concentrations of calcium carbonate nanoparticles was performed in air and water. The radiolysis products of water determine different behaviour of polymer substrate. The irradiation effect induced on polymer and the contribution of nanoparticles to the scavenging of oxygenated products that were created during ? exposure were investigated by DSC measurements over the temperature range from 340-400 K, the usual temperatures for thermal overcharge. Two kinds of carbonate particles, one type is represented by unmodified filler, while the second type is the superficially modified with stearic acid. The covering of particle surface with stearic acid confers to them a different ability in the abstraction of degradation products formed in irradiated isotactic polypropylene

  16. Analysis of the fracture behavior of polypropylene: sawdust composites

    Scientific Electronic Library Online (English)

    João C. Miguez, Suarez; Fernanda M. B., Coutinho; Thais H., Sydenstricker.

    2005-06-01

    Full Text Available Natural fiber reinforced composite is an emerging area in Polymer science. The use of lignocellulosic materials in thermoplastic composites may contribute to reduce the waste of vegetal biomass. The natural fibers are biodegradable, low cost materials having density and specific properties comparabl [...] e to those of conventional fiber composites. In this work composites of polypropylene (PP) plus maleated polypropylene (MAPP) filled with sawdust were prepared under fixed processing conditions (mixing temperature, mixing time and rate of rotation). The composites were fractured by tension and the fracture mechanisms were characterized by scanning electron microscopy. The SEM studies of the fractured surfaces of the composites indicate that the failure is due to fiber pull-out accompanied by tearing of the matrix; the pull-out increases with MAPP content.

  17. Mechanical properties of pineapple leaf fibre reinforced polypropylene composites

    Energy Technology Data Exchange (ETDEWEB)

    Arib, R.M.N. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Sapuan, S.M. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia)]. E-mail: sapuan@eng.upm.edu.my; Ahmad, M.M.H.M. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Paridah, M.T. [Faculty of Forestry, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Zaman, H.M.D. Khairul [Radiation Processing Technology Division, Malaysian Institute for Nuclear Technology Research (MINT), Bangi 43000 Kajang, Selangor (Malaysia)

    2006-07-01

    Pineapple leaf fibre, which is rich in cellulose, relative inexpensive and abundantly available has the potential for polymer-reinforced composite. The present study investigates the tensile and flexural behaviours of pineapple leaf fibre-polypropylene composites as a function of volume fraction. The tensile modulus and tensile strength of the composites were found to be increasing with fibre content in accordance with the rule of mixtures. The tensile modulus and tensile strength with a volume fraction 10.8% are 687.02 and 37.28 MPa, respectively. The flexural modulus gives higher value at 2.7% volume fraction. The flexural strength of the composites containing 5.4% volume fraction was found to be higher than that of pure polypropylene resin by 5.1%. Scanning electron microscopic studies were carried out to understand the fibre-matrix adhesion and fibre breakage.

  18. Mechanical properties of pineapple leaf fibre reinforced polypropylene composites

    International Nuclear Information System (INIS)

    Pineapple leaf fibre, which is rich in cellulose, relative inexpensive and abundantly available has the potential for polymer-reinforced composite. The present study investigates the tensile and flexural behaviours of pineapple leaf fibre-polypropylene composites as a function of volume fraction. The tensile modulus and tensile strength of the composites were found to be increasing with fibre content in accordance with the rule of mixtures. The tensile modulus and tensile strength with a volume fraction 10.8% are 687.02 and 37.28 MPa, respectively. The flexural modulus gives higher value at 2.7% volume fraction. The flexural strength of the composites containing 5.4% volume fraction was found to be higher than that of pure polypropylene resin by 5.1%. Scanning electron microscopic studies were carried out to understand the fibre-matrix adhesion and fibre breakage

  19. Analysis of the fracture behavior of polypropylene: sawdust composites

    Directory of Open Access Journals (Sweden)

    João C. Miguez Suarez

    2005-06-01

    Full Text Available Natural fiber reinforced composite is an emerging area in Polymer science. The use of lignocellulosic materials in thermoplastic composites may contribute to reduce the waste of vegetal biomass. The natural fibers are biodegradable, low cost materials having density and specific properties comparable to those of conventional fiber composites. In this work composites of polypropylene (PP plus maleated polypropylene (MAPP filled with sawdust were prepared under fixed processing conditions (mixing temperature, mixing time and rate of rotation. The composites were fractured by tension and the fracture mechanisms were characterized by scanning electron microscopy. The SEM studies of the fractured surfaces of the composites indicate that the failure is due to fiber pull-out accompanied by tearing of the matrix; the pull-out increases with MAPP content.

  20. Rheological and Thermal Behavior of Polypropylene-Kaolin Composites

    International Nuclear Information System (INIS)

    Kaolins effect on rheological behaviour of polypropylene-kaolin composites was investigated. The research found that not only the kaolin content influence the rheological behaviour but also the compounding using internal mixer and twin screw extruder. In details, viscosity and shear stress increased with addition of kaolin content. These characteristics also exhibited higher in polypropylene-kaolin composite suspensions compounded using twin screw extruder than using internal mixer. Chain scission was assumed to occur and affect the melt properties. Further justification characterized by Differential Scanning Calorimeter (DSC) showed that the effect of kaolin and loading content were more evident on the onset melting temperature and crystallinity. Besides, due to the different cooling operation in both processes, the effect of compounding on melting characteristic was conspicuous. (author)

  1. Effects of environmental ageing on HMS-polypropylene/Cloisite nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Komatsu, L. G. H., E-mail: dfparra@ipen.br; Oliani, W. L., E-mail: dfparra@ipen.br; Ferreto, H. F. R., E-mail: dfparra@ipen.br; Lugao, A. B., E-mail: dfparra@ipen.br; Parra, D. F., E-mail: dfparra@ipen.br [Nuclear and Energy Research Institute, IPEN-CNEN/SP (Brazil)

    2014-05-15

    High melt strength polypropylene Nanocomposites (NC-HMSPP) were obtained with concentrations of 0.1 and 5 wt% of Cloisite 20A. The melt intercalation, using twin screw extruder was done to homogenize the nanocomposite in presence of polypropylene graft maleic anhydride (PP-g-MA) compatibilizer agent. In this work, the manufactured dumbbell samples were settled in device for natural ageing assay. The period of exposition was January to December of 2012. The effects of environmental ageing was determined by carbonyl index (FT-IR) and the results showed that nanocomposites were more stable than HMSPP. The mechanical properties (elongation and rupture strength) were evaluated and the thermal behavior was investigated by differential scanning calorimetry (DSC) and X ray diffraction (DRX). The morphology was observed by scanning electron microscopy (SEM) in which the nanocomposites showed intense cracks on the surface.

  2. Study of blends based on polypropylene and Epdm elastomer

    International Nuclear Information System (INIS)

    Polymer blends based on EPDM elastomer and isostatic polypropylene (P P) were prepared in a Bra bender plastograph, coupled with a Brabender mixer chamber, in different composition ranges and processing conditions. It was evaluated the mechanical and flow properties of EPDM/P P blends, and also the effect of the addition of controlled degraded polypropylene (P P-deg) on the properties of these mixtures. The characterization and the study of the compatibilization degree of EPDM/P P and EPDM/P P/P P-deg blends were analyzed by differential scanning calorimetry (DSC), thermal dynamic mechanical analysis (DTMA), thermal gravimetric analysis (TGA), 13 C-nuclear magnetic resonance (13C-NMR) and scanning electron microscopy (SEM). (author)

  3. Determination of physicochemical changes in ion beam irradiated polypropylene

    International Nuclear Information System (INIS)

    Polypropylene was irradiated with 12C+ ions of 3.6 MeV energy. The spectral changes owing to ion bombardment were investigated followed by UV-VIS spectrophotometry. A gradual increase of absorbance in visible and near visible region with increase influence of ions was observed. The difference spectra shows formation of chromophoric groups with wavelength maximum near 400 nm at lower fluence, but at high fluence we observe a red shift in peak. The chromophoric groups are likely to be the extended conjugated polyene system and the red shift in peak position at high fluence may be attributed to a greater degree of conjugation. Gases (in the range of 2-80 amu) evolved due to interaction of polypropylene with 12C+ ions were measured with Residual Gas Analyzer. A large number of gaseous components were detected. This shows that polymer chain breaks into some smaller fragments which concomitantly lead to extended conjugation. (author)

  4. Carbon ion irradiation induced surface modification of polypropylene

    International Nuclear Information System (INIS)

    Polypropylene was irradiated with 12C ions of 3.6 and 5.4 MeV energies in the fluence range of 5x1013-5x1014 ions/cm2 using 3 MV tandem accelerator. Ion penetration was limited to a few microns and surface modifications were investigated by scanning electron microscopy. At the lowest ion fluence only blister formation of various sizes (1-6 μm) were observed, but at higher fluence (1x1014 ions/cm2) a three-dimensional network structure was found to form. A gradual degradation in the network structure was observed with further increase in the ion fluence. The dose dependence of the changes on surface morphology of polypropylene is discussed

  5. Effects of environmental ageing on HMS-polypropylene/Cloisite nanocomposites

    International Nuclear Information System (INIS)

    High melt strength polypropylene Nanocomposites (NC-HMSPP) were obtained with concentrations of 0.1 and 5 wt% of Cloisite 20A. The melt intercalation, using twin screw extruder was done to homogenize the nanocomposite in presence of polypropylene graft maleic anhydride (PP-g-MA) compatibilizer agent. In this work, the manufactured dumbbell samples were settled in device for natural ageing assay. The period of exposition was January to December of 2012. The effects of environmental ageing was determined by carbonyl index (FT-IR) and the results showed that nanocomposites were more stable than HMSPP. The mechanical properties (elongation and rupture strength) were evaluated and the thermal behavior was investigated by differential scanning calorimetry (DSC) and X ray diffraction (DRX). The morphology was observed by scanning electron microscopy (SEM) in which the nanocomposites showed intense cracks on the surface

  6. Ziegler-Natta catalyst for polypropylene and polyethylene nanocomposites preparation

    International Nuclear Information System (INIS)

    Polypropylene and polyethylene nanocomposites are well known for their improved properties when compared with the neat polymers. In this work we report the preparation, characterization and the activity studies of a fourth generation Ziegler-Natta catalyst for the preparation of polyolefin/clay nanocomposites. The catalyst was prepared treating an organo-modified silicate with magnesium and titanium compounds. The content of titanium and that of the magnesium of the catalyst were determined by UV-vis spectroscopy and atomic absorption respectively. The first results show that the catalyst is active for propylene polymerization being suitable for polypropylene/clay nanocomposite preparation. The catalyst activity for ethylene polymerization was also investigated. The X-ray diffraction patterns of the polyethylene samples suggest the clay exfoliation occurs in the in situ polymerization, even with high clay loading (about 9 %) indicating that a nanocomposite was formed. (author)

  7. Mechanical properties of rubberwood fibers polypropylene epoxidized natural rubber composites

    International Nuclear Information System (INIS)

    Research on rubberwood fibers-thermoplastic composites have been carried out by several workers in the past several years. The main focus was to enhance the properties of the resultant composites in view of the incompatibility of the two components. Thus, efforts have been made to enhance their properties by using coupling agents, treating the fibers and modifying the matrices. In this study, the rubberwood polypropylene composite was used as a base material and the addition of epoxidized natural rubber (ENR) is to provide a damping property of the composite with the final aim to produce a sound and noise proofing products. Initially, the processing and compositions of rubberwood fibers and polypropylene was optimized at the 50:50 w/w ratio using melt blend internal mixer. The processing parameters were established. Subsequently, the mechanical properties of the composites were determined with addition of 1-4% of ENR. (Author)

  8. Structure Modification of Isotactic Polypropylene through Chemical Crosslinking: Toughening Mechanism

    OpenAIRE

    Bouhelal, S.; Cagiao, M. E.; D. Benachour; Baltá Calleja, F. J.

    2007-01-01

    Reversibly crosslinked isotactic polypropylene (iPP) was prepared in the presence of dicumyl peroxide. The effects of the peroxide oxy-radicals in the melt were investigated in relation to the modification of the polymer. The dynamic rheology analysis of the crosslinking process was carried out by using a plastograph. The crosslinking reaction was evaluated by the Monsanto method. The resulting structure of the modified samples was studied by means of differential scanning calorimetry (...

  9. Aqueous Processes for Dyeing Generic, Unmodified Polypropylene Fiber

    OpenAIRE

    Murari L. Gupta; Fred Cook

    2010-01-01

    Acid leuco vat dyeings of polypropylene (PP) fabrics in combinations of a trichromatic series of colorants (red, yellow and blue) plus an orange were performed in order to determine the compatibility of the component colorants in the developed single stage, batch exhaust dyeing process reported earlier. Cross-section micrographs of dyed fibers revealed the absence of "ring-dyeing". Tensile tests and X-ray crystallinity results confirmed that the developed dyeing process did not significantly...

  10. Mechanical properties of polypropylene/calcium carbonate nanocomposites

    OpenAIRE

    Daniel Eiras; Luiz Antonio Pessan

    2009-01-01

    The aim of this work was to study the influence of calcium carbonate nanoparticles in both tensile and impact mechanical properties of a polypropylene homopolymer. Four compositions of PP/CaCO3 nanocomposites were prepared in a co-rotational twin screw extruder machine with calcium carbonate content of 3, 5, 7 and 10 wt. (%) The tests included SEM analyzes together with EDS analyzer and FTIR spectroscopy for calcium carbonate, tensile and impact tests for PP and the nanocomposites. The result...

  11. Asymmetric metallocene catalysts: design of ultrahigh molecular weight polypropylene plastomers

    OpenAIRE

    Cobzaru, Cecilia

    2006-01-01

    This study focuses on the synthesis of novel asymmetric ansa-metallocene catalysts of the indenyl-fluorenyl type, designed to tailor the microstructures of the resulting polypropylenes so that the portfolio of the material properties is extended toward ultrahigh molecular weight plastomers. These materials offer both the flexibility of conventional elastomers and the processing properties of thermoplastics, plus various combinations of special features, such as good heat resistance and excell...

  12. Fracture toughness of injection moulded organoclay reinforced polypropylene composites

    OpenAIRE

    Pettarin, V.; Brun, F.; A. J. Pontes; J.C. Viana; Pouzada, A. S.; Frontini, P.

    2010-01-01

    The fracture behavior of polypropylene reinforced with different amounts of PP/50% organoclay masterbatch was studied. Test pieces were prepared using a two-gated hot runner injection mould. Morphology of final pieces was analyzed by polarized optical microscopy, Xray diffraction and transmission electron microscopy. Fracture toughness was evaluated under quasi-static conditions at different positions in the molded pieces. The brittle mode of failure of PP became more ductile w...

  13. Fracture Toughness of Polypropylene-Based Particulate Composites

    OpenAIRE

    David Arencón; José Ignacio Velasco

    2009-01-01

    The fracture behaviour of polymers is strongly affected by the addition of rigid particles. Several features of the particles have a decisive influence on the values of the fracture toughness: shape and size, chemical nature, surface nature, concentration by volume, and orientation. Among those of thermoplastic matrix, polypropylene (PP) composites are the most industrially employed for many different application fields. Here, a review on the fracture behaviour of PP-based particulate composi...

  14. Microstructure and mechanical properties of Polypropylene/Polycarbonate blends

    OpenAIRE

    J.C. Viana; Bilewicz, M.; Król, M.; L. A. Dobrza?ski

    2008-01-01

    Purpose: Researches, which are presented in this paper, consider the effect of chosen different weight ratios polycarbonate blended in a polypropylene matrix (PP/PC) at variable injection moulding conditions and its effect on the microstructure, and also on fracture and flexural properties.Design/methodology/approach: Composites contain between 0 and 30 wt % of polycarbonate and changes at constant rate of 10wt%. Specimens were produced with advantage of melt manipulation technology, further ...

  15. Modification of bentonite clay and application on polypropylene nano composites

    International Nuclear Information System (INIS)

    This work consisted on the modification of Brasgel PA clay with ionic surfactant Praepagen WB and its incorporation into polypropylene. The results of infrared and DR-X was showed that the intercalation of surfactant in the clay and the incorporation of organoclay in PP matrix resulted in the formation of an intercalated structure. The impact strength of PP increased with the incorporation of organoclay. (author)

  16. GC-MS OF POLYETHYLENE AND POLYPROPYLENE THERMAL CRACKING PRODUCTS

    OpenAIRE

    Martin Bajus; Elena Hájeková; Helena Jurdáková; Robert Kubinec; Ladislav Soják

    2006-01-01

    Low-density polyethylene and polypropylene were thermally decomposed individually in a batch reactor at 450°C as a recycling route from the aspect of the production of petrochemical feedstock. The resulting transformation liquid products were analysed by high resolution gas chromatographic-mass spectrometric analysis. More detailed separation of polyalkenes splitting compounds was achieved using high resolution GC (efficiencies up to 490 000 plates) than before. The GC-MS as well as the depen...

  17. Surface modification of polypropylene membrane by polyethylene glycol graft polymerization

    International Nuclear Information System (INIS)

    Polypropylene hollow fiber microporous membranes have been used in a wide range of applications, including blood oxygenator. The hydrophobic feature of the polypropylene surface causes membrane fouling. To minimize fouling, a modification consisting of three steps: surface activation in H2 and O2 plasma, membrane immersion in polyethylene glycol (PEG) and plasma graft polymerization was performed. The membranes were characterized by contact angle measurement, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), tensile test, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Oxygen transfer of modified membranes was also tested. The stability of grafted PEG was measured in water and in phosphate buffer saline (PBS) at 37 °C. Blood compatibility of modified surfaces was evaluated by the platelet adhesion method. Water contact angel reduction from 110° to 72° demonstrates the enhanced hydrophilicity, and XPS results verify the presence of oxygenated functional groups due to the peak existence in 286 eV as a result of PEG grafting. The results clearly indicate that plasma graft-polymerization of PEG is an effective way for antifouling improvement of polypropylene membranes. Also, the results show that oxygen transfer changes in PEG grafted membranes are not significant. - Highlights: • H2 and O2 plasma graft polymerization of PEG on polypropylene membrane was carried out. • Changes in surface properties were investigated by FTIR, XPS, SEM, and AFM. • Surface wettability enhanced as a result of poly ethylene glycol grafting. • PEG grafting degree increase causes reduction of fouling and adhesion

  18. Mechanical and morphological characterization of polypropylene toughened with olefinic elastomer

    Scientific Electronic Library Online (English)

    Cybele, Lotti; Carlos A., Correa; Sebastião V., Canevarolo.

    2000-04-01

    Full Text Available The effect of incorporating (C2-C8) ethylene-octene elastomer on the mechanical properties and morphology of polypropylene copolymers has been investigated employing two types of PP copolymer, with and without nucleating agent. The results were compared to the ones presented by a commercial PP heter [...] ophase (reactor impact modified PP/EPR). The addition of the elastomer increases the toughness of the blends but reduces their stiffness. PP blends in the low elastomer content region (

  19. Mechanical and morphological characterization of polypropylene toughened with olefinic elastomer

    OpenAIRE

    Cybele Lotti; Carlos A. Correa; Canevarolo, Sebastião V

    2000-01-01

    The effect of incorporating (C2-C8) ethylene-octene elastomer on the mechanical properties and morphology of polypropylene copolymers has been investigated employing two types of PP copolymer, with and without nucleating agent. The results were compared to the ones presented by a commercial PP heterophase (reactor impact modified PP/EPR). The addition of the elastomer increases the toughness of the blends but reduces their stiffness. PP blends in the low elastomer content region (< 20%) show ...

  20. Thermal simulation for geometric optimization of metallized polypropylene film capacitors

    OpenAIRE

    El-Husseini, M.,; Venet, Pascal; Rojat, Gérard; Joubert, Charles

    2002-01-01

    In this paper, we use an analytic model to calculate the losses in the metallized polypropylene film capacitors. The model is validated experimentally for capacitors having the same capacitance but different geometry. For each group of capacitors a temperature distribution in the roll is assumed with the aim of optimizing its thermal performance. It appears that the heating of a long capacitor is higher than that of an equivalent flat capacitor subjected to the same electric stresses.

  1. Physical and Mechanical Properties of Natural Fibers Filled Polypropylene Composites and Its Recycle

    OpenAIRE

    Myrtha Karina; Holia Onggo; Anung Syampurwadi

    2007-01-01

    This study discusses the influence of natural fiber type on the performance of polypropylene and its recycle. Composites consisting of polypropylene (PP) and natural fiber from wood (Acacia mangium), water hyacinth (Eichornia crassipes), kenaf (Hibiscus cannabinus), banana (Musa paradisiaca) and empty fruit bunch of oil palm (Elaeis guineensis) were prepared by extrusion and compression process based on the ratio of 50:50% (w/w) with the addition of 2.5% polypropylene modified with maleic anh...

  2. Effect of volume fraction of Polypropylene Fiber on Mechanical Properties of Concrete

    OpenAIRE

    R. S. Rajguru,; A. R. Ghode

    2014-01-01

    In this study, the result of polypropylene fiber on mechanical properties of concrete is studied. Polypropylene fibers of 12mm cut length and 6 denier were added at volume fraction of 0%, 0.25%, 0.50%, 0.75% & 1 %.The cube, cylinder and beams wear tested under two point loads on UTM. The results showed that the addition of polypropylene fiber significantly improved the compressive strength, split tensile strength, flexural strength, reserve strength and ductility of fiber rein...

  3. Study of gel formation in polypropylene modified by gamma irradiation

    International Nuclear Information System (INIS)

    The linearity of the chains of iPP (isotactic polypropylene) confers to this, low melt strength. This fact limits the use of iPP in processes that demand high stretching. The graft of branches confers improvements in its extensional viscosity, resulting in Polypropylene with High Melt Strength (HMS-PP). Preparation process of the HMS-PP, included iPP in pellets, conditioned in plastic container containing acetylene under pressure of 110 kPa and radiation with ? source of 60Co in the doses of 5, 12.5 and 20 kGy. The gel fraction of the samples was determined by the extraction of soluble components in xylene under boiling for 12 hours at 138 deg C. The soluble part of the samples was decanted with the total volatilization of the xylene to the room temperature (25 deg C) and deposition in glass blades. These samples had been characterized by Optic Microscopy, Scanning Electron Microscopy and Infrared Spectroscopy. In this study of the morphology, we obtained the formation of gel and microgel of polypropylene with higher incidence in HMS-PP 20 kGy. (author)

  4. Mixing of Isotactic and Syndiotactic Polypropylenes in the Melt

    Energy Technology Data Exchange (ETDEWEB)

    CLANCY,THOMAS C.; PUTZ,MATHIAS; WEINHOLD,JEFFREY D.; CURRO,JOHN G.; MATTICE,WAYNE L.

    2000-07-14

    The miscibility of polypropylene (PP) melts in which the chains differ only in stereochemical composition has been investigated by two different procedures. One approach used detailed local information from a Monte Carlo simulation of a single chain, and the other approach takes this information from a rotational isomeric state model devised decades ago, for another purpose. The first approach uses PRISM theory to deduce the intermolecular packing in the polymer blend, while the second approach uses a Monte Carlo simulation of a coarse-grained representation of independent chains, expressed on a high-coordination lattice. Both approaches find a positive energy change upon mixing isotactic PP (iPP) and syndiotactic polypropylene (sPP) chains in the melt. This conclusion is qualitatively consistent with observations published recently by Muelhaupt and coworkers. The size of the energy chain on mixing is smaller in the MC/PRISM approach than in the RIS/MC simulation, with the smaller energy change being in better agreement with the experiment. The RIS/MC simulation finds no demixing for iPP and atactic polypropylene (aPP) in the melt, consistent with several experimental observations in the literature. The demixing of the iPP/sPP blend may arise from attractive interactions in the sPP melt that are disrupted when the sPP chains are diluted with aPP or iPP chains.

  5. Pubovaginal sling with a low-cost polypropylene mesh

    Directory of Open Access Journals (Sweden)

    Fransber R. Rodrigues

    2007-10-01

    Full Text Available OBJECTIVE: The aim of this study was to present the results of pubovaginal sling with a low-cost polypropylene mesh in the treatment of stress urinary incontinence MATERIALS AND METHODS: 118 women diagnosed with stress urinary incontinence (SUI due to urethral hypermobility or intrinsic sphincteric deficiency, treated with pubovaginal sling (PVS with a low-cost polypropylene mesh confectioned by the surgeon, were analyzed. All patients had a basic evaluation that included a medical history, physical examination, stress tests and urodynamic investigation RESULTS: The average follow up was of 42 months. Urethral hypermobility was observed in 67% of the cases. The process was carried out on an outpatient basis on 67 patients. Intra-operative complications included 4 vesical injuries, treated with catheterization for 3 days. There were 13 early complications, of which 8 were urinary retentions treated with vesical drainage for 1 to 3 weeks and 3 vaginal extrusions of the mesh treated with covering of the sections with mucous membrane. There was a need for 6 urethrolysis in patients who presented irritative and postoperative obstructive symptoms; 81.3% of the patients were considered cured, while 9.3% had significant improvement. Three initially unsuccessful cases required sling reconfiguration. All cases were eventually cured CONCLUSION: The construction of a pubovaginal sling using a low-cost polypropylene mesh is a safe and effective technique for the relief of SUI. It should be considered an alternative, especially for patients in public health systems with low financial resources.

  6. Pubovaginal sling with a low-cost polypropylene mesh

    Scientific Electronic Library Online (English)

    Fransber R., Rodrigues; Romulo, Maroccolo Filho; Roberto R., Maroccolo; Lucio C., Paiva; Fernando A., Diaz; Eduardo C., Ribeiro.

    2007-10-01

    Full Text Available OBJECTIVE: The aim of this study was to present the results of pubovaginal sling with a low-cost polypropylene mesh in the treatment of stress urinary incontinence MATERIALS AND METHODS: 118 women diagnosed with stress urinary incontinence (SUI) due to urethral hypermobility or intrinsic sphincteric [...] deficiency, treated with pubovaginal sling (PVS) with a low-cost polypropylene mesh confectioned by the surgeon, were analyzed. All patients had a basic evaluation that included a medical history, physical examination, stress tests and urodynamic investigation RESULTS: The average follow up was of 42 months. Urethral hypermobility was observed in 67% of the cases. The process was carried out on an outpatient basis on 67 patients. Intra-operative complications included 4 vesical injuries, treated with catheterization for 3 days. There were 13 early complications, of which 8 were urinary retentions treated with vesical drainage for 1 to 3 weeks and 3 vaginal extrusions of the mesh treated with covering of the sections with mucous membrane. There was a need for 6 urethrolysis in patients who presented irritative and postoperative obstructive symptoms; 81.3% of the patients were considered cured, while 9.3% had significant improvement. Three initially unsuccessful cases required sling reconfiguration. All cases were eventually cured CONCLUSION: The construction of a pubovaginal sling using a low-cost polypropylene mesh is a safe and effective technique for the relief of SUI. It should be considered an alternative, especially for patients in public health systems with low financial resources.

  7. Property Relationship in Organosilanes and Nanotubes Filled Polypropylene Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Alejandra J. Monsiváis-Barrón

    2014-10-01

    Full Text Available Polypropylene composites with different filler contents were prepared by creating a masterbatch containing 3 wt%. filler. A variety of silanol groups were used to synthetized three compounds in different media trough a sol-gel process with acetic acid, formic acid and ammonium hydroxide as catalysts. Besides, four different nanotubular fillers were also used to analyze their behavior and compare it with the effect caused by the silanol groups. These tubular structures comprise: unmodified halloysite, carbon nanotubes and functionalized halloysite and carbon nanotubes. Morphological characterization in SEM and STEM/TEM showed dispersion in the polypropylene matrix. According to TGA and DSC measurements thermal behavior remain similar for all the composites. Mechanical test in tension demonstrate that modulus of the composites increases for all samples with a major impact for materials containing silanol groups synthetized in formic acid. Rheological measurements show a significantly increment in viscosity for samples containing unmodified and modified carbon nanotubes. No difference was found for samples containing silanol groups and halloysite when compared to neat polypropylene. Finally, the oxygen transmission rate increased for all samples showing high barrier properties only for samples containing natural and functionalized halloysite nanotubes.

  8. Nanocomposites of irradiated polypropylene with clay are degradable?

    Science.gov (United States)

    Komatsu, L. G. H.; Oliani, W. L.; Lugao, A. B.; Parra, D. F.

    2016-01-01

    In nowadays, polypropylene (PP) based nanocomposites containing organically modified montmorillonite (MMT), have gained great attention in the automobilistic industries, construction, paints, packageing, plastic components of the telecommunication industries. The HMSPP (high melt strength polypropylene) is a polypropylene modified by irradiation process, under acetylene atmosphere, in which irradiation occurs in 60Co gamma source. However, when those materials are submitted to environmental ageing nanocomposites demonstrated high decomposition level after 1 year. This fact can be due to presence the metallic ions present in the montmorillonite. The HMS-PP and the Cloisite 20A (MMT) were mixed in twin-screw extruder using maleic anhydride as compatibilizer. In this work two formulations of nanocomposites at 0.1 and 5 wt% of clay were submitted to the environmental and thermal ageing to analyze the effects of degradation on the HMSPP nanocomposites. The evaluation of thermal properties was analyzed by Differential Scanning Calorimetry (DSC) and the chemical alterations were investigated by Carbonyl Index (CI), through Fourier Transformed Infrared (FTIR) technique. The basal distance was measured by X-ray diffraction (DRX) and the clay elements were analyzed by X-ray Fluorescence (WDXRF). The aim of this work was to understand the effects of degradation of the HMS-PP/clay nanocomposites.

  9. Contact angle analysis of corona treated polypropylene films

    International Nuclear Information System (INIS)

    In this work, the effect of the surface modification of polypropylene films via corona treatment was investigated. Polypropylene films were treated with negative and positive corona discharge, at atmospheric pressure, for 5 minutes, at two different temperatures – 25 °C and 90 °C. The changes in the surface free energy were investigated by means of contact angle measurements. The Bickerman's method was applied to determine the polar and dispersion components of the polymer surface free energy, on the basis of the theory of Owens, Wendt, Kaelble and Uy. Atomic force microscopy was used to analyze the polymer surface morphology changes of the films with temperature. According to the findings, in all cases the corona treatment increases the surface free energy of polypropylene films and its polar part, in comparison with the untreated samples. The effects of negative and positive corona polarities display some specific features which could be associated with different charged group introduced onto the film surface during the corona treatment. The total final effect depends on the simultaneous action of the two competing factors – temperature and corona polarity. The most pronounced effect was observed for high temperature negative corona treatment.

  10. Development and characterisation of injection moulded, all-polypropylene composites

    Directory of Open Access Journals (Sweden)

    A. Kmetty

    2013-02-01

    Full Text Available In this work, all-polypropylene composites (all-PP composites were manufactured by injection moulding. Prior to injection moulding, pre-impregnated pellets were prepared by a three-step process (filament winding, compression moulding and pelletizing. A highly oriented polypropylene multifilament was used as the reinforcement material, and a random polypropylene copolymer (with ethylene was used as the matrix material. Plaque specimens were injection moulded from the pellets with either a film gate or a fan gate. The compression moulded sheets and injection moulding plaques were characterised by shrinkage tests, static tensile tests, dynamic mechanical analysis and falling weight impact tests; the fibre distribution and fibre/matrix adhesion were analysed with light microscopy and scanning electron microscopy. The results showed that with increasing fibre content, both the yield stress and the perforation energy significantly increased. Of the two types of gates used, the fan gate caused the mechanical properties of the plaque specimens to become more homogeneous (i.e., the differences in behaviour parallel and perpendicular to the flow direction became negligible.

  11. Tibetan Apples and Oranges: Surficial Sutures and Overlapping Lithospheres

    Science.gov (United States)

    Chen, W. P.; Hung, S. H.; Wang, C. Y.; Tseng, T. L.

    2014-12-01

    Multi-scale, finite-frequency tomography across the Himalayas-Tibet shows a clear, subhorizontal anomaly of high VP and VSin the upper mantle that can be traced from under N. India all the way to beneath central Tibet. This configuration of the "Greater India" (GI), or the submerged, northern portion of the Indian shield, is combined with other constraints to reconstruct position of the Indian lithospheric mantle (ILM) relative to Asia back to about 15 Ma ago, or the onset of the latest magmatic activity in Tibet. By then, the leading edge of the ILM (Indian mantle front, IMF) has advanced subhorizontally past the entire Lhasa terrane and also probably have caused the lithospheric mantle beneath the Qiangtang terrane to thicken. The thickening is likely to have led to Rayleigh-Taylor instability, causing widespread but small volume of magmatic activity in northern Tibet. Meanwhile, the detached lithospheric mantle foundered through the upper mantle to rest at the bottom of the mantle transition zone (MTZ), just above the lower mantle. This detached lithospheric mantle manifests itself as a large-scale seismic anomaly of high compressional wave speed (VP) but curiously is undetectable through shear-waves. Based on laboratory data for nominally anhydrous olivine and its high-pressure polymorphs (NAO), the discordant results between P- and S-waves is explained by abundant hydroxyls in the foundered lithospheric mantle, a hypothesis supported by other evidences as well. Since NAO can hold ~1 wt% of water throughout the upper mantle and the MTZ, foundering of thickened lithospheric mantle caused by continental collision is an under-appreciated but effective pathway for water to enter the deep mantle. Currently, the Indus-Yarlung suture between northern India and the Lhasa terrane appears to be an inactive, crustal feature, as the GI continues to pass beneath it. On the other hand, even though the IMF has now advanced northward beyond the Bangong-Nujiang suture (BNS), which marks the suture between the Lhasa (southern Tibet) and the Qiangtang terranes (central Tibet) in the Mesozoic, the BNS seems to have been a zone of deformation over lithospheric scale when the IMF interacted with the Qiangtang lithosphere about 15 Ma ago. Indeed the Moho around this zone is highly disturbed, a feature not found elsewhere under Tibet.

  12. Celastrol nanoparticles inhibit corneal neovascularization induced by suturing in rats

    Directory of Open Access Journals (Sweden)

    Li ZR

    2012-03-01

    Full Text Available Zhanrong Li1, Lin Yao1, Jingguo Li2, Wenxin Zhang1, Xianghua Wu1, Yi Liu1, Miaoli Lin1, Wenru Su1, Yongping Li1, Dan Liang11State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, 2School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, People's Republic of ChinaPurpose: Celastrol, a traditional Chinese medicine, is widely used in anti-inflammation and anti-angiogenesis research. However, the poor water solubility of celastrol restricts its further application. This paper aims to study the effect of celastrol nanoparticles (CNPs on corneal neovascularization (CNV and determine the possible mechanism.Methods: To improve the hydrophilicity of celastrol, celastrol-loaded poly(ethylene glycol-block-poly(?-caprolactone nanopolymeric micelles were developed. The characterization of CNPs was measured by dynamic light scattering and transmission electron microscopy analysis. Celastrol loading content and release were assessed by ultraviolet-visible analysis and high performance liquid chromatography, respectively. In vitro, human umbilical vein endothelial cell proliferation and capillary-like tube formation were assayed. In vivo, suture-induced CNV was chosen to evaluate the effect of CNPs on CNV in rats. Immunohistochemistry for CD68 assessed the macrophage infiltration of the cornea on day 6 after surgery. Real-time quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay were used to evaluate the messenger ribonucleic acid and protein levels, respectively, of vascular endothelial growth factor, matrix metalloproteinase 9, and monocyte chemoattractant protein 1 in the cornea.Results: The mean diameter of CNPs with spherical shape was 48 nm. The celastrol loading content was 7.36%. The release behavior of CNPs in buffered solution (pH 7.4 showed a typical two-phase release profile. CNPs inhibited the proliferation of human umbilical vein endothelial cells in a dose-independent manner and suppressed the capillary structure formation. After treatment with CNPs, the length and area of CNV reduced from 1.16 ± 0.18 mm to 0.49 ± 0.12 mm and from 7.71 ± 0.94 mm2 to 2.29 ± 0.61 mm2, respectively. Macrophage infiltration decreased significantly in the CNP-treated corneas. CNPs reduced the expression of vascular endothelial growth factor, matrix metalloproteinase 9, and monocyte chemoattractant protein 1 in the cornea on day 6 after suturing.Conclusion: CNPs significantly inhibited suture-induced CNV by suppressing macrophage infiltration and the expression of vascular endothelial growth factor and matrix metalloproteinase 9 in the rat cornea.Keywords: celastrol, PEG-b-PCL nanopolymeric micelles, corneal neovascularization, macrophages, VEGF, MMP-9

  13. Transcutaneous Serdev Suture For Buttock’s Lift

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    Nikolay Serdev

    2012-10-01

    Full Text Available This article presents the author's technique and experience in the treatment of the flaccid "unhappy buttock" form with his surgical procedure of buttock lift by suture, without incision scars. The author first presented this new operation technique on a national level at the 2nd Annual Meeting of the National Bulgarian Society for Aesthetic Surgery and Aesthetic Medicine in Sofia on March 18, 1994 [1] and internationally at many scientific meetings over the world [2, 3, 4…]. The result is a visual change in the buttock position to a higher one, which elongates the lower limbs and changes the proportions between lower and upper half of the body. The aim of this study is to describe a mini-invasive procedure of beautification of the buttock form without scars by creating a lifting effect on the buttock's subcutaneous tissue, using a suture that takes the inferiorly positioned deep fibrose tissue and fixes it upwards to the sacro-cutaneous fascia, discovered by the author. Aesthetic and technical considerations required properly sculpting the buttocks into a higher position, demonstrating nicely rounded form. Preoperative shape is discussed and patient evaluations, operative techniques, postoperative management and results after 4 years of experience are emphasized. 1032 female patients, and 26 male patients aged 18-62 years, with ptosis and cellulite on the buttocks were treated since 1993 on an outpatient basis by the "Serdev suture technique without visible scars". Important instrumentarium is a long, curved, elastic needle and Polycon semi-elastic Bulgarian antimicrobial polycaproamide long term (in 2 years absorbable surgical threads Polycon, produced in Bulgaria. This operation has been performed either alone or after ultrasonic assisted liposculpture (UAL that reduces the amount of fat and heaviness. All patients reported a high degree of satisfaction. A stable improvement in the buttock position and form was observed for the period described. In the postoperative period the complication rate was minimal and resolved in the first 4-5 days post operative period. The skin puncture in the perianal zone makes antibiotic prophylaxis obligatory as well as a strict follow up for the first 7 days. Some pain in the sitting position was observed for at least 5 to 10 days, but all other social and professional duties and activities were possible. This outpatient procedure is effective in the correction of buttock laxity and ptosis and creates a new form, universally accepted as "happy buttocks".

  14. End-on extramucosal single layer suture with double anchoring in the submucosa on rabbits

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    Nascimento Luiz Roberto do

    1999-01-01

    Full Text Available The techniques of gastrointestinal surgical sutures have been frequently focused in controversial publications. These ones concern not only anastomosis? types but also about thread types and how to apply them. The values of the submucosa as layer of greatest resistence of the digestive tube was already known since the past century. The aim of this study is to avaluate the suture in an extramucosal single-layer suture with double anchoring of the submucosa, a technical detail not found in the searched literature. This experiment was carried out using 36 white,male adults New Zealand, rabbits divided into three groups which differed only regarding day of re-operation and euthanasia, as followed: group I ( 4 days, group II (7 days and group III ( 15 days. Two transversal and parallel gastrotomies were perfomed in the same animal, one distal and other proximal, of with 4 cm extension each. In these gastrotomies two types of sutures were alternated : 1- End-on extramucosal single-layer suture and 2- End-on extramucosal single-layer suture, with double anchoring in the submucosa. Macroscopic and microscopic studies were perfomed on the suture line in both gastrotomies and in each period of euthanasia. Except for the serosa item whose results were similar for both sutures, statiscally, the extramucosal single-layer suture, with double anchoring of submucosa layer showed better macro and microscopic results than the extramucosal single-layer suture in group I (4 days. In the others periods of euthanasia (groups II and III, the statistical results were similar.

  15. Single-layer continuous suture contributes to the reduction of surgical complications in digestive tract anastomosis involving special anatomical locations

    OpenAIRE

    LI, GUO-CAI; ZHANG, YU-CHUN; Xu, Yong; Zhang, Fang-Cheng; Huang, Wei-hua; XU, JIAN-QING; MA, QING-JIU

    2013-01-01

    The key point of digestive cancer surgery is reconstruction and anastomosis of the digestive tract. Traditional anastomoses involve double-layer interrupted suturing, manually or using a surgical stapler. In special anatomical locations, however, suturing may become increasingly difficult and the complication rate increases accordingly. In this study, we aimed to investigate the feasibility and safety of a new manual suturing method, the single-layer continuous suture in the posterior wall of...

  16. The role of micrometric wollastonite particles on stress whitening behavior of polypropylene composites

    International Nuclear Information System (INIS)

    The micromechanism and susceptibility to stress whitening during tensile straining of micrometric wollastonite mineral-reinforced polypropylenes is studied by electron microscopy and compared with unreinforced neat polypropylenes. Mineral-reinforced polypropylene composite exhibit significantly reduced susceptibility to stress whitening, and are characterized by lower gray level in the plastically deformed stress whitened zone. This behavior is attributed to the effective reinforcement of polypropylene by wollastonite that acts in concert increasing the tensile modulus of the composite and restricts plastic deformation of the matrix. The increase in tensile modulus is explained in terms of a three-phase model involving matrix, particle, and interface zone. Furthermore, isothermal crystallization indicated that the reinforcement mineral increases the rate of nucleation with consequent increase in % bulk crystallinity. The reinforcement of polypropylene alters the primary micromechanism of stress whitening from deformation bands/crazing in neat polypropylenes to wedge/ridge-tearing in mineral-reinforced polypropylene composites. The final fracture in reinforced polypropylene occurs by a mixed mode consisting of fibrillation and brittle mode, while crazing-tearing and brittle deformation are fracture modes for neat polypropylene

  17. The effect of electrostatic force on air filtration by polypropylene filter media

    International Nuclear Information System (INIS)

    In this paper, the effect of irradiation with 60Co on the efficiency and strength of the polypropylene filter media is mainly researched. The charge density of polypropylene fibre is evaluated by radiation discharge method. Based on isolated cylinder model, the efficiency of the polypropylene filter media, which takes account of the effect of impaction, interception, diffusion and electrostatic, is calculated. A better agreement between theoretical analysis and experimental results is obtained. The results indicate that electrostatic force is the most important factor in solid aerosol filtration of the polypropylene filter media

  18. CFD Analysis of Coolant Flow in VVER-440 Fuel Assemblies with the Code ANSYS CFX 10.0

    International Nuclear Information System (INIS)

    From the aspect of planning the power upgrading of nuclear reactors - including the VVER-440 type reactor - it is essential to get to know the flow field in the fuel assembly. For this purpose we have developed models of the fuel assembly of the VVER-440 reactor using the ANSYS CFX 10.0 CFD code. At first a 240 mm long part of a 60 degrees segment of the fuel pin bundle was modelled. Implementing this model a sensitivity study on the appropriate meshing was performed. Based on the development of the above described model, further models were developed: a 960 mm long part of a 60-degree-segment and a full length part (2420 mm) of the fuel pin bundle segment. The calculations were run using constant coolant properties and several turbulence models. The impacts of choosing different turbulence models were investigated. The results of the above-mentioned investigations are presented in this paper. (authors)

  19. Cork extractives exhibit thermo-oxidative protection properties in polypropylene-cork composites and as direct additives for polypropylene

    OpenAIRE

    Aroso, Ivo; Fernandes, E. M.; Pires, R. A.; J.F. Mano; R. L. Reis

    2015-01-01

    The thermo-oxidative stability of polypropylene (PP) in composites containing 15 wt.% of cork and the performance of selected cork extracts as stabilizing additives for PP was evaluated by Oxidation Induction Time (OIT) and by Oxidation Onset Temperature (OOT). The results showed that cork increases the OIT of PP in the composite and it was identified that the cork extractives fraction is responsible for such behavior. Selected cork extracts with high antioxidant capacity (determined by dpph ...

  20. Application analysis on different suture of scleral flap in trabeculectomy

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    Ning Liu

    2014-05-01

    Full Text Available AIM: To research the application of scleral flap suture in trabeculectomy. METHODS: Totally 114 primary angle-closure glaucoma patients, aged from 36-72 years old, were selected as the objects, and randomly divided into research group and control group. The two groups received different administration methods. Traditional sewing method of sclera flap was used in research group and improved sewing method of sclera flap was used in control group. RESULTS: There was statistical differences between postoperative intraocular pressure of the patients in the observation group and the control group after 1d; 2wk; 1, 3mo(PPP>0.05.CONCLUSION: It is safe and effective that the improved sewing method of sclera flap for trabeculectomy of acute angle-closure glaucoma, and it is a better method to avoid the occurrence of shallow anterior chamber than the traditional sewing method in the early stage after operation.

  1. Single-incision laparoscopic splenectomy with innovative gastric traction suture

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    Srikanth G

    2011-01-01

    Full Text Available Laparoscopic splenectomy is now the gold standard for patients with idiopathic thrombocytopenic purpura (ITP undergoing splenectomy. There are a few reports in literature on single-incision laparoscopic (SIL splenectomy. Herein, we describe a patient undergoing SIL splenectomy for ITP without the use of a disposable port device. We report a 20-year-old female patient with steroid-refractory ITP having a platelet count of 14,000/cmm who underwent a SIL splenectomy. Dissection was facilitated by the use of a single articulating grasper and a gastric traction suture and splenic vessels were secured at the hilum with an endo-GIA stapler. She made an uneventful postoperative recovery and was discharged on the second postoperative day. She is doing well with no visible scar at 8-month follow-up.

  2. Monotonic and cyclic responses of impact polypropylene and continuous glass fiber-reinforced impact polypropylene composites at different strain rates

    KAUST Repository

    Yudhanto, Arief

    2016-03-08

    Impact copolymer polypropylene (IPP), a blend of isotactic polypropylene and ethylene-propylene rubber, and its continuous glass fiber composite form (glass fiber-reinforced impact polypropylene, GFIPP) are promising materials for impact-prone automotive structures. However, basic mechanical properties and corresponding damage of IPP and GFIPP at different rates, which are of keen interest in the material development stage and numerical tool validation, have not been reported. Here, we applied monotonic and cyclic tensile loads to IPP and GFIPP at different strain rates (0.001/s, 0.01/s and 0.1/s) to study the mechanical properties, failure modes and the damage parameters. We used monotonic and cyclic tests to obtain mechanical properties and define damage parameters, respectively. We also used scanning electron microscopy (SEM) images to visualize the failure mode. We found that IPP generally exhibits brittle fracture (with relatively low failure strain of 2.69-3.74%) and viscoelastic-viscoplastic behavior. GFIPP [90]8 is generally insensitive to strain rate due to localized damage initiation mostly in the matrix phase leading to catastrophic transverse failure. In contrast, GFIPP [±45]s is sensitive to the strain rate as indicated by the change in shear modulus, shear strength and failure mode.

  3. Polypropylene and polypropylene/polyglecaprone (Ultrapro(r)) meshes in the repair of incisional hernia in rats

    Scientific Electronic Library Online (English)

    Edivaldo Massazo, Utiyama; Maria Beatriz Sartor de Faria, Rosa; Marina de Paula, Andres; Jocielle Santos de, Miranda; Sérgio Henrique Bastos, Damous; Cláudio Augusto Vianna, Birolini; Luciana Lamarão, Damous; Edna Frasson de Souza, Montero.

    2015-06-01

    Full Text Available PURPOSE: To compare the inflammatory response of three different meshes on abdominal hernia repair in an experimental model of incisional hernia. METHODS: Median fascial incision and skin synthesis was performed on 30 Wistar rats. After 21 days, abdominal hernia developed was corrected as follows: [...] 1) No mesh; 2) Polypropylene mesh; and, 3) Ultrapro(r) mesh. After 21 days, the mesh and surrounding tissue were submitted to macroscopic (presence of adhesions, mesh retraction), microscopic analysis to identify and quantify the inflammatory and fibrotic response using a score based on a predefined scale of 0-3 degrees, evaluating infiltration of macrophages, giant cells, neutrophils and lymphocytes. RESULTS: No significant difference was seen among groups in adherences, fibrosis, giant cells, macrophages, neutrophils or lymphocytes (p>0.05). Mesh shrinkage was observed in all groups, but also no difference was observed between polypropylene and Ultrapro mesh (7.0±9.9 vs. 7.4±10.1, respectively, p=0.967). Post-operatory complications included fistula, abscess, dehiscence, serohematic collection and reherniation, but with no difference among groups (p=0.363). CONCLUSION: There is no difference between polypropylene (high-density) and Ultrapro(r) (low-density) meshes at 21 days after surgery in extraperitoneal use in rats, comparing inflammatory response, mesh shortening, adhesions or complications.

  4. Effects of maleated polypropylene on the morphology, thermal and mechanical properties of short carbon fiber reinforced polypropylene composites

    International Nuclear Information System (INIS)

    Highlights: → Carbon fibers (CFs) are the most widely used advanced reinforcing fiber materials. → Improvement of adhesion between polypropylene (PP) matrix and CF were aimed. → PP matrix was modified by addition of maleic anhydride grafted PP (PP-g-MAH). → Mechanical properties of the composites were improved by PP-g-MAH compatibilizer. → Modification of matrix with PP-g-MAH was improved the interfacial adhesion. -- Abstract: The aim of this study was to determine the effect of the maleic anhydride grafted polypropylene (PP-g-MAH) on the properties of short carbon fiber (CF) reinforced polypropylene (PP) composites. The composites were prepared by melt blending and injection molding techniques at different percentages of CF. Tensile tests, hardness, differential scanning calorimeter (DSC) and scanning electron microscopy (SEM) were performed to characterize the physical and morphological properties of the prepared composites. It was observed from SEM photographs that modification with PP-g-MAH improved the interfacial adhesion between the carbon fibers and PP matrix. The ultimate tensile strength, hardness and modulus values of modified PP composites were higher compared to the values of CF reinforced PP composites. Melting temperature of all composites was not changed significantly with increasing CF content; however degree of crystallinity values were decreased with the increasing CF content level.

  5. [Introduction, designs and assessment of a suture set for standard cardiovascular surgery].

    Science.gov (United States)

    Wariishi, Seiichiro; Nishimori, Hideaki; Fukutomi, Takashi; Yamamoto, Masaki; Sasaguri, Shiro

    2011-03-01

    A packing system for threads and needles has been introduced with the aim of efficient operations in the field of cardiovascular surgery. To provide competent and safe surgery to patients, a suture set was developed according to the standard cardiovascular surgery procedure with cooperation between doctors and nurses at Kochi University Hospital. This suture set was introduced to all surgeries for adults conducted under cardiopulmonary bypass. Herein, we describe problems before the introduction, the process of the introduction, and designs of the suture set. In addition, we assessed the present condition since the introduction of this suture set. Many positive opinions were obtained from both doctors and nurses, and the suture set thus yielded a satisfactory assessment. Psychological stability and safety provided by the suture set may lead not only to cost reduction but also to an increased level of surgery as a whole. In addition, it may now be possible to provide simpler and more efficient cardiovascular surgery with this set. This suture set will serve as a useful model for thread and needle packing systems to be developed at various facilities in the future. PMID:21404558

  6. Immunostimulatory sutures that treat local disease recurrence following primary tumor resection

    International Nuclear Information System (INIS)

    Neuroblastoma is a common childhood cancer that often results in progressive minimal residual disease after primary tumor resection. Cytosine-phosphorothioate-guanine oligonucleotides (CpG ODN) have been reported to induce potent anti-tumor immune responses. In this communication, we report on the development of a CpG ODN-loaded suture that can close up the wound following tumor excision and provide sustained localized delivery of CpG ODN to treat local disease recurrence. The suture was prepared by melt extruding a mixture of polylactic acid-co-glycolic acid (PLGA 75:25 0.47 dL g-1) pellets and CpG ODN 1826. Scanning electron microscopy images showed that the sutures were free of defects and cracks. UV spectrophotometry measurements at 260 nm showed that sutures provide sustained release of CpG ODN over 35 days. Syngeneic female A/J mice were inoculated subcutaneously with 1 x 106 Neuro-2a murine neuroblastoma wild-type cells and tumors were grown between 5 to 10 mm before the tumors were excised. Wounds from the tumor resection were closed using CpG ODN-loaded sutures and/or polyglycolic acid Vicryl suture. Suppression of neuroblastoma recurrence and mouse survival were significantly higher in mice where wounds were closed using the CpG ODN-loaded sutures relative to all other groups. (communication)

  7. Immunostimulatory sutures that treat local disease recurrence following primary tumor resection

    Energy Technology Data Exchange (ETDEWEB)

    Intra, Janjira; Zhang Xueqing; Salem, Aliasger K [Division of Pharmaceutics, College of Pharmacy, University of Iowa, Iowa City, IA 52242 (United States); Williams, Robin L; Zhu Xiaoyan [Department of Surgery, Roy J and Lucille Carver College of Medicine, University of Iowa, Iowa City, IA 52242 (United States); Sandler, Anthony D, E-mail: aliasger-salem@uiowa.edu [Department of Surgery and Center for Cancer and Immunology Research, Children' s National Medical Center, Washington DC 20010 (United States)

    2011-02-15

    Neuroblastoma is a common childhood cancer that often results in progressive minimal residual disease after primary tumor resection. Cytosine-phosphorothioate-guanine oligonucleotides (CpG ODN) have been reported to induce potent anti-tumor immune responses. In this communication, we report on the development of a CpG ODN-loaded suture that can close up the wound following tumor excision and provide sustained localized delivery of CpG ODN to treat local disease recurrence. The suture was prepared by melt extruding a mixture of polylactic acid-co-glycolic acid (PLGA 75:25 0.47 dL g{sup -1}) pellets and CpG ODN 1826. Scanning electron microscopy images showed that the sutures were free of defects and cracks. UV spectrophotometry measurements at 260 nm showed that sutures provide sustained release of CpG ODN over 35 days. Syngeneic female A/J mice were inoculated subcutaneously with 1 x 10{sup 6} Neuro-2a murine neuroblastoma wild-type cells and tumors were grown between 5 to 10 mm before the tumors were excised. Wounds from the tumor resection were closed using CpG ODN-loaded sutures and/or polyglycolic acid Vicryl suture. Suppression of neuroblastoma recurrence and mouse survival were significantly higher in mice where wounds were closed using the CpG ODN-loaded sutures relative to all other groups. (communication)

  8. Normal Development of Sutures and synchondroses in the central skull base : CT study

    International Nuclear Information System (INIS)

    To evaluate the developmental patterns of the sutures and synchondroses in the central skull base. We evaluated the CT scans of 109 children (age range 29 days to 15 years) with no skull base abnormality who had undergone axial CT of the skull base with 1-mm collimation. Using a five-tier scheme, we analyzed the developmental patterns of the 18 sutures and synchondroses related to the sphenoid and occipital bones. Fusion of the sutures and synchondroses related to the sphenoid bone progressed rapidly during the first two years. Thereafter, changes in the sphenoid bone were dominated by pneumatization of the sphenoid sinus. Fusion of the synchondroses within the sphenoid body, including intersphenoidal, intrapresphenoidal, intrapostsphenoidal synchondrosis occurred early and in most cases was graded ?3D4. Fusion of the sphenosquamosal, sphenoethmoidal, and frontosphenoidal sutures was delayed, and residual sclerosis was a common finding. Except for Kerckring-supraoccipital synchondrosis, fusion of the six sutures and synchondroses related to the occipital bone occurred more gradually than that of those related to the sphenoid bone. Among these, fusion of the occipitomastoidal suture and petro-occipital synchondrosis was the last to occur. A knowledge of the developmental patterns of sutures and synchondroses can help differentiate normal conditions from those such as fracture, osseous dysplasia, or congenital malformation, which are abnormal. Our results provide certain basic information about skull base maturity in children. (author)

  9. Study of comparison between skin sutures and skin staplers: 400 case studies

    Directory of Open Access Journals (Sweden)

    Vikash Lal

    2015-01-01

    Full Text Available Background: There are various ways the skin approximation whether be it sutures, staplers, glues, sterile tapes all of these have the same purpose of but the one which provides the best scar with least wound infection and consumes least time is the one that should be used. So here we have studied 400 patients over a period of 20 months comparing skin sutures with staplers and their outcome with respect to time consumed and percentage of complication. Methods: A prospective type of study was conducted from January 2013 to August 2014 at Dr. D Y Patil Hospital, Nerul for comparison between skin sutures and skin staplers in terms of effectiveness and complications in 400 patients who underwent various surgical procedures. The patients included in this study were randomly selected from those who underwent various surgical procedures which were either elective or emergency with various incisions. Results: The average time taken for skin closure by staplers is 1.84 min per 10 cm of wound and for skin sutures, it is 6.61 min per 10 cm of wound and complication rate for suturing is 30% and for staplers it is about 12%. Conclusion: Outcome of staplers is cosmetically superior to skin sutures with overall less complication as compared to skin sutures. [Int J Res Med Sci 2015; 3(1.000: 277-281

  10. Midpalatal suture maturation: Classification method for individual assessment before rapid maxillary expansion

    Science.gov (United States)

    Angelieri, Fernanda; Cevidanes, Lucia H. S.; Franchi, Lorenzo; Gonçalves, João R.; Benavides, Erika; McNamara, James A.

    2014-01-01

    Introduction In this study, we present a novel classification method for individual assessment of midpalatal suture morphology. Methods Cone-beam computed tomography images from 140 subjects (ages, 5.6-58.4 years) were examined to define the radiographic stages of midpalatal suture maturation. Five stages of maturation of the midpalatal suture were identified and defined: stage A, straight high-density sutural line, with no or little interdigitation; stage B, scalloped appearance of the high-density sutural line; stage C, 2 parallel, scalloped, high-density lines that were close to each other, separated in some areas by small low-density spaces; stage D, fusion completed in the palatine bone, with no evidence of a suture; and stage E, fusion anteriorly in the maxilla. Intraexaminer and interexaminer agreements were evaluated by weighted kappa tests. Results Stages A and B typically were observed up to 13 years of age, whereas stage C was noted primarily from 11 to 17 years but occasionally in younger and older age groups. Fusion of the palatine (stage D) and maxillary (stage E) regions of the midpalatal suture was completed after 11 years only in girls. From 14 to 17 years, 3 of 13 (23%) boys showed fusion only in the palatine bone (stage D). Conclusions This new classification method has the potential to avoid the side effects of rapid maxillary expansion failure or unnecessary surgically assisted rapid maxillary expansion for late adolescents and young adults. PMID:24182592

  11. Radiological assessment of skull base changes in children with syndromic craniosynostosis: role of ''minor'' sutures

    International Nuclear Information System (INIS)

    This study aims to identify the premature synostosis of ''major'' and ''minor'' sutures of the four ''sutural arches'' of the skull and to perform a morphometric analysis in children with syndromic craniosynostosis in order to evaluate changes in the skull base linked with premature suture synostosis. We reviewed multiplanar high-resolution CT images, implemented with 3D reconstructions, from 18 patients with complex syndromic craniosynostosis and compared them with 18 age-matched healthy subjects. We assessed the calvarial sutures and their extension to the skull base, and then we correlated specific types of synostosis with the size, shape and symmetry of the cranial fossae. We found a marked asymmetry of the skull base growth in all patients. The synostotic involvement around the coronal ring caused a reduction in the growth of the anterior and middle fossae. The size of the posterior cranial fossa was related not only to ''major'' but also to ''minor'' suture synostosis of the lambdoid and parieto-squamosal arches. Changes in the skull base and craniofacial axis symmetry are due to structural and functional relationships between ''major'' and ''minor'' skull sutures, suggesting a structural and functional relationship between the neurocranium and basicranium. The early recognition of prematurely closed skull base sutures may help clinicians and neurosurgeons to establish correct therapeutic approaches. (orig.)

  12. Introduction of a New Suture Method in Repair of Peripheral Nerves Injured with a Sharp Mechanism

    Directory of Open Access Journals (Sweden)

    Alireza Saied

    2015-09-01

    Full Text Available Background: The standard method for repair of an injured peripheal nerve is epineural repair with separate sutures. Herein we describe a method in which the nerve is sutured with continous sutures. In fact this method has not been utilized for nerve repair previously and our purpose was to compare it to the standard method. If it proved to be successful it would replace the standard method in certain circumstances. Methods: The proposal of the clinical trial was given a reference number form the ethics comitee. 25 dogs in which the scaitic nerve was cut by a sharp blade under genaeral anesthesia were divided randomly into three groups: control (5 dogs, repair of sciatic nerve with simple sutures (10 and repair with continous sutures (10. In the control group the nerve was not repaired at all. After 6 weeks the dogs were killed and the nerve was studied by light and electronic microscopes. The amount of consumed suture material, time of repair, myelin thickness and axon diiameter were examined. Ultrastructural studies were performed to assess degeneration and regeneration findings. Results: Time of repair and the amount of consumed suture material were significantly lower in the continous group (P

  13. Anatomy-Based navigation for ventriculostomy: Nasion-coronal suture distance measurement

    Directory of Open Access Journals (Sweden)

    Mevci Özdemir

    2014-09-01

    Full Text Available Objective: In this study we aimed to determine a landmark that can be measured through the skin with nasal mid-point (bregma to coronal suture, and additionally an average value was calculated. We report, to our knowledge, the distance between the nasion-coronal sutures is reported for the first time in Turkish population. Methods: The study included 30 craniums and 30 frontal bones. Each skull from midline nasal suture to coronal suture curved up at the distance was measured with tape measure. Results: Mean values were determined. Nasal suture between coronal suture distance average 12,2 cm (min10,3 cm, up to 13,5 cm were detected. Conclusion: Nasal suture is an easily palpable area through the skin. A small incision is carried down through skin to bone at the spot 12 cm back from the nasion 3 cm lateral to the midline for ventricular drainage operation. This data provide practical information for neurosurgeon and is available everywhere. J Clin Exp Invest 2014; 5 (3: 368-370

  14. Achilles tendon suture deteriorates tendon capillary blood flow with sustained tissue oxygen saturation – an animal study

    Directory of Open Access Journals (Sweden)

    Vogt Peter M

    2009-08-01

    Full Text Available Abstract Background Treatment of ruptured Achilles tendons currently constitutes of conservative early functional treatment or surgical treatment either by open or minimal invasive techniques. We hypothesize that an experimental Achilles tendon suture in an animal model significantly deteriorates Achilles tendon microcirculation immediately following suturing. Methods Fifteen Achilles tendons of eight male Wistar rats (275–325 g were included. After preparation of the Achilles tendon with a medial paratendinous approach, Achilles tendon microcirculation was assessed using combined Laser-Doppler and spectrophotometry (Oxygen-to-see regarding: - tendinous capillary blood flow [arbitrary units AU] - tendinous tissue oxygen saturation [%] - tendinous venous filling pressure [rAU] The main body of the Achilles tendon was measured in the center of the suture with 50 Hz. 10 minutes after Achilles tendon suture (6-0 Prolene, a second assessment of microcirculatory parameters was performed. Results Achilles tendon capillary blood flow decreased by 57% following the suture (70 ± 30 AU vs. 31 ± 16 AU; p Conclusion Achilles tendon suture in anaesthetised rats causes an acute loss of capillary perfusion and increases postcapillary venous filling pressures indicating venous stasis. The primary hypothesis of this study was confirmed. In contrast, tendinous tissue oxygen saturation remains unchanged excluding acute intratendinous hypoxia within the first 10 minutes after suture. Further changes of oxygen saturation remain unclear. Furthermore, it remains to be determined to what extent reduced capillary blood flow as well as increased postcapillary stasis might influence tendon healing from a microcirculatory point of view in this animal setting.

  15. [Quantification of Wood Flour and Polypropylene in Chinese Fir/Polypropylene Composites by FTIR].

    Science.gov (United States)

    Lao, Wan-li; Li, Gai-yun; Zhou, Qun; Qin, Te-fu

    2015-06-01

    The ratio of wood and plastic in Wood Plastic Composites (WPCss) influences quality and price, but traditional thermochemical methods cannot rapidly and accurately quantify the ratio of wood/PP in WPCss. This paper was addressed to investigate the feasibility of quantifying the wood flour content and plastic content in WPCss by Fourier Transform Infrared (FTIR) spectroscopy. With Chinese fir, polypropylene (PP) and other additives as raw materials, 13 WPCs samples with different wood flour contents, ranging from 9.8% to 61.5%, were prepared by modifying wood flour, mixing materials and extrusion pelletizing. The samples were analyzed by FTIR with the KBr pellets technique. The absorption peaks of WPCss at 1059, 1 033 and 1 740 cm(-1) are considered as characteristic of Chinese fir, and the absorption peaks at 1 377, 2 839 and 841 cm(-1) are typical of PP by comparing the spectra of WPCss with that of Chinese fir, PP and other additives. The relationship between the wood flour content, PP content in WPCss and their characteristic IR peaks height ratio was established. The results show that there is a strong linear correlation between the wood flour content in WPCss and I1 059/l 1 377/I1 033, /I1377, R2 are 0.992 and 0.993 respectively; there is a high linear correlation between the PP content in WPCss and I1 377/I1 740, I2 839 /I1 740 R2 are 0.985 and 0.981, respectively. Quantitative methods of the wood flour content and PP content in WPCss by FTIR were developed, the predictive equations of the wood flour content in WPCss are y = 53.297x-9. 107 and y = 55.922x-10.238, the predictive equations of the PP content in WPCss are y = 6.828 5x+5.403 6 and y = 8.719 7x+3.295 8. The results of the accuracy test and precision test show that the method has strong repeatability and high accuracy. The average prediction relative deviations of the wood flour content and PP content in WPCss are about 5%. The prediction accuracy has been improved remarkably, compared to thermochemical methods. More importantly, FTIR is more easy-handing. This experiment may provide a simple, rapid and accurate method for quantification of wood flour and PP in Chinese fir/PP composites. PMID:26601364

  16. A randomized controlled experimental study comparing chitosan coated polypropylene mesh and Proceed™ mesh for abdominal wall defect closure

    Directory of Open Access Journals (Sweden)

    S.T. Jayanth

    2015-12-01

    Conclusion: Chitosan coated polypropylene mesh was found to have similar efficacy to Proceed™ mesh. Chitosan coated polypropylene mesh, can act as an anti adhesive barrier when used in the repair of incisional hernias and abdominal wall defects.

  17. A miniature tension sensor to measure surgical suture tension of deformable musculoskeletal tissues during joint motion.

    Science.gov (United States)

    Kiriyama, Yoshimori; Matsumoto, Hideo; Toyama, Yoshiaki; Nagura, Takeo

    2014-02-01

    The aim of this study was to develop a new suture tension sensor for musculoskeletal soft tissue that shows deformation or movements. The suture tension sensor was 10 mm in size, which was small enough to avoid conflicting with the adjacent sensor. Furthermore, the sensor had good linearity up to a tension of 50 N, which is equivalent to the breaking strength of a size 1 absorbable suture defined by the United States Pharmacopeia. The design and mechanism were analyzed using a finite element model prior to developing the actual sensor. Based on the analysis, adequate material was selected, and the output linearity was confirmed and compared with the simulated result. To evaluate practical application, the incision of the skin and capsule were sutured during simulated total knee arthroplasty. When conventional surgery and minimally invasive surgery were performed, suture tensions were compared. In minimally invasive surgery, the distal portion of the knee was dissected, and the proximal portion of the knee was dissected additionally in conventional surgery. In the skin suturing, the maximum tension was 4.4 N, and this tension was independent of the sensor location. In contrast, the sensor suturing the capsule in the distal portion had a tension of 4.4 N in minimally invasive surgery, while the proximal sensor had a tension of 44 N in conventional surgery. The suture tensions increased nonlinearly and were dependent on the knee flexion angle. Furthermore, the tension changes showed hysteresis. This miniature tension sensor may help establish the optimal suturing method with adequate tension to ensure wound healing and early recovery. PMID:24436492

  18. Triclosan-coated sutures and sternal wound infections: a prospective randomized clinical trial.

    Science.gov (United States)

    Steingrimsson, S; Thimour-Bergström, L; Roman-Emanuel, C; Scherstén, H; Friberg, Ö; Gudbjartsson, T; Jeppsson, A

    2015-12-01

    Surgical site infection is a common complication following cardiac surgery. Triclosan-coated sutures have been shown to reduce the rate of infections in various surgical wounds, including wounds after vein harvesting in coronary artery bypass grafting patients. Our purpose was to compare the rate of infections in sternotomy wounds closed with triclosan-coated or conventional sutures. A total of 357 patients that underwent coronary artery bypass grafting were included in a prospective randomized double-blind single-center study. The patients were randomized to closure of the sternal wound with either triclosan-coated sutures (Vicryl Plus and Monocryl Plus, Ethicon, Inc., Somerville, NJ, USA) (n?=?179) or identical sutures without triclosan (n?=?178). Patients were followed up after 30 days (clinical visit) and 60 days (telephone interview). The primary endpoint was the prevalence of sternal wound infection according to the Centers for Disease Control and Prevention (CDC) criteria. The demographics in both groups were comparable, including age, gender, body mass index, and rate of diabetes and smoking. Sternal wound infection was diagnosed in 43 patients; 23 (12.8 %) sutured with triclosan-coated sutures compared to 20 (11.2 %) sutured without triclosan (p?=?0.640). Most infections were superficial (n?=?36, 10.1 %), while 7 (2.0 %) were deep sternal wound infections. There were 16 positive cultures in the triclosan group and 17 in the non-coated suture group (p?=?0.842). The most commonly identified main pathogens were Staphylococcus aureus (45.4 %) and coagulase-negative staphylococci (36.4 %). Skin closure with triclosan-coated sutures did not reduce the rate of sternal wound infection after coronary artery bypass grafting. (clinicaltrials.gov: NCT01212315). PMID:26432552

  19. Peritoneostomy with latex coated polypropylene: experimental study in rats Peritoniostomia com polipropileno revestido por látex: estudo experimental em ratos

    OpenAIRE

    Renato Hugues Atique Claudio; Augusto Diogo Filho; Divino Oliveira Mamede Filho

    2006-01-01

    PURPOSE: To evaluate if latex coated polypropylene mesh leads to less adhesions formation. METHODS: 90 rats were distributed in three groups. Group I (control) was submitted to median laparotomy and posterior synthesis; Group II (polypropylene) was submitted to a segment resection of the abdominal wall, and the defect was corrected with a polypropylene mesh; Group III using the new material (latex coated polypropylene). After 45 days the euthanasia procedure was done and the adhesions were ev...

  20. The interaction between the whipstitch sutures of multi-strand ACL grafts and interference screw fixation.

    Science.gov (United States)

    Bravman, Jonathan; Ishak, Charbel; Gelber, Jonathan; Namkoong, Suk; Jazrawi, Laith M; Kummer, Frederick J

    2006-01-01

    In a recent experiment examining the effect of interference screw sizing on the fixation stability of multi-strand anterior cruciate ligament grafts, we noticed a large variation in fixation strengths and attributed it to the suturing of the grafts and its interaction with the screw. We performed an experiment using interference screws for fixation of hamstring grafts within a bone tunnel model to compare how the presence of sutures affected graft fixation. We found that having sutures along the region of the graft that contacts the screw within the bone tunnel can increase graft fixation strength 100%. PMID:16878838

  1. [The influence of formaldehyde, ethylene oxide, high pressure on the tension of silk sutures].

    Science.gov (United States)

    Lin, Y L; Cai, J H

    1997-05-01

    120 pieces of silk suture (1# & 4#) were sterilized with formaldehyde at different time period. Group II and III each had 20 pieces and was disinfected with ethylene oxide or high pressure respectively. The tension of each silk suture was measured with tensomether. The result showed that there was no significant difference compared with the control groups (P > 0.05). This suggests that silk suture maintains the same tension in the experiments after repeated sterilization with formaldehyde, with ethylene oxide, or with highpressure sterilization once. PMID:9304983

  2. Interactions of lead with carboxyl and hydroxyl-decorated(10, 0) single-walled carbon nanotubes: First-principle calculations

    Energy Technology Data Exchange (ETDEWEB)

    Bastos, M., E-mail: mirele.quimica@gmail.com; Camps, I., E-mail: icamps@unifal-mg.edu.br

    2013-11-15

    Absorption of Pb on a zigzag (10, 0) carbon nanotube (CNT) surface, pure and functionalized with carboxyl (-COOH) and hydroxyl (-OH) groups was investigated using the density functional theory. Binding energy calculations were performed and indicated that adsorption of the Pb metal on the surface of the three nanotubes were stable, through a chemisorption. Therefore, CNTs are a feasible active material for filters that retain such metal. After Pb adsorption, the CNT and COOH-CNT conductivity changed, from semiconductor to half-metallic for CNT and from semiconductor to metallic for COOH-CNT, which can serve as a signal for Pb sensor. In all three cases adsorption produced a change in nanotube magnetism, which can also serve as a sensitive signal for chemical sensors. After adsorption of Pb, the changes in binding energy, charge transfer, conductance and magnetism may lead to the different response in the CNTs-based sensors. Thus, it is expected that these results could provide helpful information for the design and fabrication of the Pb sensing devices.

  3. Calculation and Determination of natural frequencies for fresh fuel transportation package set with ANSYS 10.0 software

    International Nuclear Information System (INIS)

    The fresh fuel for Bushehr Nuclear Power Plant-1 is due to be transported inside special containers which are supposed to be designed to stand against vibrations and impacts in order to protect the fuel from any possible damage. In order to perform die structural dynamic analysis of the containers, while being subjected to impact of dynamic forces, it is necessary to perform the vibration analysis which will lead to the vibrational modes and their natural frequencies for the structure of the containers. The vibration opposition of the containers must be far beyond the critical resonance. The resonance frequencies about the natural frequency of the structure will cause the enhancement of the oscillation range and may be ended with its disintegration. Determination of the natural frequencies and their mode shapes can be achieved by vibration-analyzing-methods. The amount of the natural frequency of any structure depends strongly on its shape, material and its lean points, as well as the amount and the type of the loads which the structure will be subjected to. In the present research, the container of the fresh fuel of Bushehr Nuclear Power Plant-1 is simulated by ANSYSR10.0 and their ten natural frequency modes have been calculated

  4. Tube Polypropylene: A Neglected Critical Parameter for Protein Adsorption During Biospecimen Storage.

    Science.gov (United States)

    Kofanova, Olga A; Mommaerts, Kathleen; Betsou, Fay

    2015-08-01

    This biospecimen research case study illustrates the importance of a neglected pre-analytical factor, the polypropylene type of storage tubes. We measured amyloid ?1-42 peptide and showed that a non-irradiated, homopolymer type of polypropylene has the lowest adsorption properties. PMID:26186497

  5. Changes to the chemical structure of isotactic-polypropylene induced by ion-beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Oka, T., E-mail: oka.toshitaka@jaea.go.j [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Naka, Ibaraki 319-1195 (Japan); Oshima, A. [The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Motohashi, R.; Seto, N.; Watanabe, Y.; Kobayashi, R.; Saito, K. [Research Institute for Science and Engineering, Waseda University, Shinjuku, Tokyo 169-8555 (Japan); Kudo, H. [School of Engineering, The University of Tokyo, Naka, Ibaraki 319-1188 (Japan); Murakami, T. [Department of Accelerator Physics and Engineering, National Institute of Radiological Sciences, Inage, Chiba 263-8555 (Japan); Washio, M.; Hama, Y. [Research Institute for Science and Engineering, Waseda University, Shinjuku, Tokyo 169-8555 (Japan)

    2011-02-15

    The chemical structures of various ion-beam irradiated isotactic-polypropylene samples were studied. Results of micro-Fourier transform infrared spectroscopy and ultraviolet-visible spectroscopy suggest not only the linear energy transfer, but also the fluence is effective in local transformation of the isotactic-polypropylene.

  6. Effect of particle size, coupling agent and DDGS additions on Paulownia wood polypropylene composites

    Science.gov (United States)

    The mechanical, flexural, thermal, and physical characteristics of wood plastic composites employing Paulownia wood (PP) flour derived from 36-mo-old trees blended with polypropylene (PP) were analyzed. Composites of 25% and 40% w/w of PW and 0-10% by weight of maleated polypropylene (MAPP) were pr...

  7. Polypropylene mesh repair of a unilateral, congenital hernia in the inguinal region in a Thoroughbred filly

    OpenAIRE

    Moorman, Valerie J.; Jann, Henry W.

    2009-01-01

    A 2-day-old Thoroughbred intact female was presented for a large subcutaneous swelling in the right inguinal region. Surgical repair was performed using a double layer polypropylene mesh. To the authors’ knowledge, there have been no previous reports of surgical repair of congenital body wall hernias with polypropylene mesh in foals.

  8. Conversion of atactic polypropylene waste to fuel oil. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bhatia, J.

    1981-04-01

    A stable, convenient thermal pyrolysis process was demonstrated on a large scale pilot plant. The process successfully converted high viscosity copolymer atactic polypropylene to predominantly liquid fuels which could be burned in commercial burners. Energy yield of the process was very high - in excess of 93% including gas phase heating value. Design and operating data were obtained to permit design of a commercial size atactic conversion plant. Atactic polypropylene can be cracked at temperatures around 850/sup 0/F and residence time of 5 minutes. The viscosity of the cracked product increases with decrease in time/temperature. A majority of the pyrolysis was carried out at a pressure of 50 psig. Thermal cracking of atactic polypropylene is seen to result in sigificant coke formation (0.4% to 0.8% on a weight of feed basis) although the coke levels were of an order of magnitude lower than those obtained during catalytic cracking. The discrepancy between batch and continuous test data can be atrributed to lowered heat transfer and diffusion rates. Oxidative pyrolysis is not seen as a viable commercial alternative due to a significant amount of water formation. However, introduction of controlled quantities of oxygen at lower temperatures to affect change in feedstock viscosity could be considered. It is essential to have a complete characterization of the polymer composition and structure in order to obtain useful and duplicable data because the pyrolysis products and probably the pyrolysis kinetics are affected by introduction of abnormalities into the polymer structure during polymerization. The polymer products from continuous testing contained an olefinic content of 80% or higher. This suggests that the pyrolysis products be investigated for use as olefinic raw materials. Catalytic cracking does not seem to result in any advantage over the Thermal Cracking process in terms of reaction rates or temperature of operation.

  9. GC-MS OF POLYETHYLENE AND POLYPROPYLENE THERMAL CRACKING PRODUCTS

    Directory of Open Access Journals (Sweden)

    Martin Bajus

    2006-03-01

    Full Text Available Low-density polyethylene and polypropylene were thermally decomposed individually in a batch reactor at 450°C as a recycling route from the aspect of the production of petrochemical feedstock. The resulting transformation liquid products were analysed by high resolution gas chromatographic-mass spectrometric analysis. More detailed separation of polyalkenes splitting compounds was achieved using high resolution GC (efficiencies up to 490 000 plates than before. The GC-MS as well as the dependence of homomorphy factors and isopropyl group increments on the number of carbon atoms of alk-1-enes, alk-2-enes, alka-?,?-dienes and alkanes were used for identification of separated analytes.Thermal cracking of LDPE products in the range C5-C23 were characterized by quintets of peaks in the chromatogram which were assigned to n-alkanes, alk-1-enes, (E-alk-2-enes, (Z-alk-2-enes and alka-?,?-dienes with average quantitative ratio 1 : 1.2 : 0.07 : 0.05 : 0.08. In fraction up to n-C8 140 GC peaks were separated and identified, including around 30 acyclic octenes.In contrast to the polyethylene thermal cracking which yields products with straight-chain hydrocarbon structure, polypropylene cracking is characterized by the formation of compounds with branched and high prevailingly unsaturated hydrocarbon structure. The pretention of this analytical problem lies in stereoisomerism and corresponding multicomponentity of branched alkenes, alkadienes and alkanes in a broad range of carbon atoms number as main decomposition products of polypropylene. In the liquid fraction up to n-C8 84 peaks including around 40 acyclic octenes were identified. Other 149 GC peaks were analysed in the C9-C25 fraction with quantitative ratio of alkane : alkene : alkadiene equal to 1 : 17 : 4. High resolution GC allowed more detailed and more reliable analysis of multicomponent polyalkenes cracking products.

  10. Synthesis and characterization of CNTs using polypropylene waste as precursor

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • A facile method for producing CNTs from polypropylene waste is proposed. • Optimization of Ni/Mo mole ratio using RSM suggests the adequacy of cubic model. • Process parameters were optimized by RSM using Box–Behnken four factorial design. • Maximum desirability of one suggested that 514% of CNTs would yield over Ni4Mo0.2MgO1. • Increase in Ni/Mo ratio from 0.5 to 20, inner diameter of CNTs decreases from 25 to 2 nm. - Abstract: We study the synthesis of MWCNTs using polypropylene waste as a precursor and Ni/Mo/MgO as a catalyst by the combustion technique. Molar ratios of Ni, Mo and MgO in the Ni/Mo/MgO catalyst were optimized using response surface methodology (RSM) to obtain the maximum yield of CNTs. The mole ratio 4/0.2/1 was found to yield more carbon product. Further, process parameters such as combustion temperature, combustion time, polymer and catalyst weight were optimized by RSM using Box–Behnken three-level and four-factorial design. The best possible combination of process parameters (combustion time of 10 min, combustion temperature of 800 °C, polymer weight of 5 g and catalyst weight of 150 mg) for maximum yield of CNTs was obtained. HRTEM indicates that the diameter of CNTs depends on the catalyst composition used for the synthesis of CNTs. The results of the study indicate a facile method for producing CNTs from polypropylene waste

  11. Use of polypropylene mesh in hernioplasty by Lichtenstein's technique

    International Nuclear Information System (INIS)

    INTRODUCTION. The aim of present study was to assess the benefit using the prosthesis (polypropylene mesh) in the hernioplasty using the Lichtenstein's technique in the 'Joaquin Albarran' Clinical Surgical Hospital. METHODS. A prospective study (with an interval of 14 months) was conducted in 140 surgical interventions carried out using the Lichtenstein's technique in patients presenting with inguinal hernia. One hundred and ten patients were excluded due to interventions were of ambulatory method. The following data were studied: type of hernia found in the physical examination, age, sex, and race, type of job, intervention's date, and technique used as well as the complications during the immediate postoperative time. Also, the hernia's relapse after operation, surgical complications and tolerance to polypropylene mesh were taking into account. RESULTS. There was predominance of male sex confirming a direct influence among types of jobs requiring a strong physical effort and the appearance of inguinal hernias (63,3 %). There were only three complications: a hematoma and two seromas. There were not relapses and any case of infection, both local and systemic. The use of prophylactic antibiotics showed an appropriate cost-benefit relationship. CONCLUSIONS. The old age, the male sex and a sustained physical effort have a directly proportional relation to appearance of inguinal hernias. The feasibility of Lichtenstein's hernioplasty, the null incidence of hernia relapses and no appearance of complications including the rejection to prosthetic material, favoured the use of polypropylene in this plasty. Authors recommended the use of perioperative prophylactic antibiotic therapy to avoid wound's infection and thus to secure the result of surgical intervention and its durability. (author)

  12. Polypropylene Track Membranes for Mikro and Ultrafiltration of Chemically Aggressive Agents

    CERN Document Server

    Kravets, L I; Apel, P Yu

    2000-01-01

    A production process for track membranes on the basis of chemically resistant polymer polypropylene has been developed. Research in all stages of the formation of the polypropylene track membranes has been conducted: the main principles of the process of chemical etching of polypropylene irradiated with accelerated ions have been investigated, the most effective structure of the etchant for a selective etching of the heavy ion tracks has been selected, the parameters of etching have been optimized. A method for sensibilization of latent tracks in polypropylene by effect of solvents has been developed. It helps to reach a significant increase in etching selectivity. A method for destruction of an absorbed chromocontaining layer on the surface of polypropylene track membranes formed during etching has been elaborated. Experimental samples of the membranes for micro and ultrafiltration have been obtained and their properties have been studied in course of their exploitation in chemically aggressive agents. For t...

  13. Radiation grafting of styrene and acrylic acid onto pre-irradiated polypropylene fabric

    International Nuclear Information System (INIS)

    Grafting copolymerization of styrene and acrylic acid onto polypropylene fabric has been studied by using a pre-irradiation technique. The polypropylene fabric samples were irradiated by γ-ray and electron beam under the conditions of air and nitrogen gas. The effect of absorbed dose, monomer concentration in solvent, reaction temperature and reaction time on the degree of grafting were determined. The effects of metallic salts and sulphuric acid on the grafting yield of acrylic acid were also examined. The samples irradiated by electron beam gave a much higher degree of grafting than those by γ-ray when styrene was grafted to polypropylene fabric. However, the grafting yield of acrylic acid on polypropylene fabric in the condition of metallic salts and sulphuric acid showed the opposite results from the case of styrene. This effect was reasonably interpreted by assuming that the grafting is dominated by trapped radicals and peroxides in polypropylene. (author)

  14. Physical and Mechanical Properties of Natural Fibers Filled Polypropylene Composites and Its Recycle

    Directory of Open Access Journals (Sweden)

    Myrtha Karina

    2007-01-01

    Full Text Available This study discusses the influence of natural fiber type on the performance of polypropylene and its recycle. Composites consisting of polypropylene (PP and natural fiber from wood (Acacia mangium, water hyacinth (Eichornia crassipes, kenaf (Hibiscus cannabinus, banana (Musa paradisiaca and empty fruit bunch of oil palm (Elaeis guineensis were prepared by extrusion and compression process based on the ratio of 50:50% (w/w with the addition of 2.5% polypropylene modified with maleic anhydride (MAPP. The effect of fiber type on the composites was evaluated. Physical and mechanical properties were studied. The composite showed significantly different properties based on the fiber type. Kenaf filled composite showed high tensile strength, break strain and modulus of elasticity properties but least absorbed water. Banana fiber filled propylene composite is comparable with that of kenaf. In general, recycle polypropylene can replace virgin polypropylene since their natural fibers filled composites showed similar mechanical and physical properties.

  15. Mechanical and Morphological Properties of Polypropylene/Polyoxymethylene Blends

    OpenAIRE

    Sirirat Wacharawichanant; Tanakorn Siripattanasak

    2013-01-01

    This work studies the mechanical and morphological properties of polypropylene (PP)/polyoxymethylene (POM) blends. The PP/POM blends were prepared by melting-blend with an internal mixer. The contents of PP were used at 10%, 20%, 30%, 70%, 80% and 90% by weight. The phase morphology of the blends was observed by scanning electron microscope (SEM) due to the mechanical properties depended on the phase morphology. The results show the decrease of the impact strength, Young’s modulus and tensil...

  16. Electron-beam processing of wood fiber reinforced polypropylene

    International Nuclear Information System (INIS)

    A reactive extrusion procedure has been developed for wood fiber reinforced thermoplastic composites, applying a small amount of reactive additive that compatibilizes the synthetic and natural polymer components, with a subsequent Electron Beam treatment which is a productive method of creating active sites on both matrix polymer and fibrous reinforcement. Wood fiber and polypropylene (PP) bound together through reactive additive results in a composite which has not only a high modulus of elasticity, but also significantly higher flexural and tensile strength and improved thermal tolerance over the conventional wood fiber-PP blends, and over the PP itself. (author)

  17. Morphology-mechanical Property Relationship of Polypropylene/starch Blends

    OpenAIRE

    C. H. Azhari; Wong, S F

    2001-01-01

    The influence of morphology on mechanical property of several polypropylene/starch (PP/starch) blends of varying compositions was studied. The blends prepared were at wt%PP/wt%starch of 97.5/2.5, 95/5, 92.5/7.7, 90/10, 87.5/12.5 and 85/15. The morphology of the blends observed, using scanning electron microscopy showed them to be immiscible blends with distinct polymer-starch domains at high starch volume fractions (85%PP/15%starch-87.5%PP/12.5%starch), which gradually showed the morphology o...

  18. Morphology, thermal properties and mechanical relaxations of metallocene syndiotactic polypropylenes

    OpenAIRE

    López Moya, Ester; Gómez-Elvira González, José Manuel; Benavente, R.; Pérez, Ernesto

    2012-01-01

    The complex polymorphic behaviour of four syndiotactic polypropylene (sPP) samples have been analysed by means of DSC and WAXD techniques. Two samples (sPP1, sPP2) were synthesised via metallocene polymerization by using the ansa-zirconocene Ph2C(Cp)(9-Flu)ZrCl2 as catalyst. Finally, two additional specimens with different molar masses (sPP1-Fr1, sPP1-Fr2) were prepared from the most syndiotactic sPP1 sample by temperature gradient extraction. The WAXD analysis shows that together with the or...

  19. [Alloplastics of median ventral hernias with polypropylene gauze].

    Science.gov (United States)

    Moshkova, T A

    2008-01-01

    The article summarizes an experience with 83 alloplastics with polypropylene gauze performed in 75 patients with median ventral hernias. An original method is described of confrontation and retention of the rectal abdominal muscles in the middle position with the help of prosthesis. The proposed method of operation improves its results: postoperative complications developed two times rarer, less amount of the implanted synthetic material used, the patients were at the hospital for a shorter time. In these patients there were no recurrent hernias and diastasis recti abdominis. PMID:18942434

  20. Comparison of life cycle assessment for different volume polypropylene jars

    OpenAIRE

    Krki? Nevena M.; Lazi? Vera L.; Šuput Danijela Z.

    2012-01-01

    When deciding what packaging is the most appropriate for a product there are many factors to be considered. One of them is the impact of the packaging on environment. In this work, life cycle inventory and life cycle assessment of two different volume packagings were compared. The data were collected on the types and amounts of materials and energy consumption in the process of packaging and distribution of hand cream packed in polypropylene jars of 200 and 350 mL. Life cycle inventory ...

  1. Recovering and recompounding polypropylene from lead-acid automotive batteries

    Science.gov (United States)

    Pfaff, Reinhard

    1990-10-01

    Materials recycling has to satisfy a number of criteria, including: it must not harm the environment; it should produce almost no residue; it should create high-level products with definable lifetimes; and it should be economical. With these requirements in mind, this article describes the reuse of plastic scrap recovered from spent automotive batteries. Necessary development work for separating, treating and recompounding polypropylene is described. Numerous tests have been performed on the resulting molding compounds in order to specify the materials and their processability.

  2. Casting thin films of cellulose nitrate, polycarbonate, and polypropylene

    International Nuclear Information System (INIS)

    Plastic films of cellulose nitrate (collodion), polycarbonate (LexanTM), and polypropylene have many uses in the production of nuclear targets, as well as in other research areas. The uses and properties of these films are summarized, and techniques for producing them by casting onto glass and other surfaces in controlled thicknesses are described. Special apparatus and precautions for producing such films in the thickness range from 0.04 ?m to 10 ?m, and in sizes up to 100 mmx125 mm have been developed. (orig.)

  3. Polypropylene/organoclay/SEBS nanocomposites with toughness-stiffness properties

    DEFF Research Database (Denmark)

    Sanporean (nee Potarniche), Catalina-Gabriela; Vuluga, Zina

    2014-01-01

    Polypropylene nanocomposites with a different amount of styrene-ethylene-butylene-styrene block copolymer (SEBS)/clay were prepared via a melt mixing technique. To improve the dispersion of commercial organoclay (denoted as OMMT), various amounts of SEBS were incorporated. At a fixed content of OMMT, the mechanical properties were improved with increasing SEBS content. The obtained nanocomposites were characterized through X-ray diffraction (XRD), differential scanning calorimetry (DSC-TG) and mechanical tests. The thermal-morphological-mechanical properties were investigated. The nanomaterials presented an improved decomposition temperature, a small decrease in tensile strength, a higher Young's modulus and a spectacular increase of 300% in impact strength.

  4. Radiation Damage of Polypropylene Fiber Targets in Storage Rings

    CERN Document Server

    Rohdjess, H; Bisplinghoff, J; Bollmann, R; Büsser, K; Diehl, O; Dohrmann, F; Engelhardt, H P; Eversheim, P D; Greiff, J; Gross, A; Gross-Hardt, R; Hinterberger, F; Igelbrink, M; Langkau, R; Maier, R; Mosel, F; Müller, M; Muenstermann, M; Prasuhn, D; Von Rossen, P; Scheid, H; Schirm, N; Schwandt, F; Scobel, W; Trelle, H J; Wellinghausen, A; Wiedmann, W; Woller, K; Ziegler, R

    2004-01-01

    Thin polypropylene (CH$_2$) fibers have been used for internal experiments in storage rings as an option for hydrogen targets. The change of the hydrogen content due to the radiation dose applied by the circulating proton beam has been investigated in the range $1\\cdot10^6$ to $2\\cdot10^8$~Gy at beam momenta of 1.5 to 3 GeV/c by comparing the elastic pp-scattering yield to that from inelastic p-carbon reactions. It is found that the loss of hydrogen as a function of applied dose receives contributions from a fast and a slow component.

  5. Precision Polyolefin Nanoalloy Polypropylene/Poly(ε-caprolactone).

    Science.gov (United States)

    Liu, Yuan; Wang, Ning; Dong, Jin-Yong

    2015-11-01

    This communication reports the first example of precision polyolefin nanoalloys where an exotic immiscible polymer is nanometrically dispersed with stability in a polyolefin matrix in a highly controlled mode. Following the preparation of polypropylene/multiwalled carbon nanotubes nanocomposites (PP/MWCNTs) by in situ Ziegler-Natta polymerization, the hydroxyl groups on the surfaces of individual MWCNTs are used to initiate ring-opening polymerization of ε-caprolactone, resulting in PP/poly(ε-caprolactone) (PCL) alloy with PCL grafted on MWCNTs. Upon phase formation, the PP/MWCNTs-g-PCL alloys exhibit a unique PCL dispersion morphology, which is stable and solely governed by PCL molecular weight. PMID:26345280

  6. Shyok Suture Zone, N Pakistan: late Mesozoic Tertiary evolution of a critical suture separating the oceanic Ladakh Arc from the Asian continental margin

    Science.gov (United States)

    Robertson, Alastair H. F.; Collins, Alan S.

    2002-02-01

    The Shyok Suture Zone (Northern Suture) of North Pakistan is an important Cretaceous-Tertiary suture separating the Asian continent (Karakoram) from the Cretaceous Kohistan-Ladakh oceanic arc to the south. In previously published interpretations, the Shyok Suture Zone marks either the site of subduction of a wide Tethyan ocean, or represents an Early Cretaceous intra-continental marginal basin along the southern margin of Asia. To shed light on alternative hypotheses, a sedimentological, structural and igneous geochemical study was made of a well-exposed traverse in North Pakistan, in the Skardu area (Baltistan). To the south of the Shyok Suture Zone in this area is the Ladakh Arc and its Late Cretaceous, mainly volcanogenic, sedimentary cover (Burje-La Formation). The Shyok Suture Zone extends northwards (ca. 30 km) to the late Tertiary Main Karakoram Thrust that transported Asian, mainly high-grade metamorphic rocks southwards over the suture zone. The Shyok Suture Zone is dominated by four contrasting units separated by thrusts, as follows: (1). The lowermost, Askore amphibolite, is mainly amphibolite facies meta-basites and turbiditic meta-sediments interpreted as early marginal basin rift products, or trapped Tethyan oceanic crust, metamorphosed during later arc rifting. (2). The overlying Pakora Formation is a very thick (ca. 7 km in outcrop) succession of greenschist facies volcaniclastic sandstones, redeposited limestones and subordinate basaltic-andesitic extrusives and flow breccias of at least partly Early Cretaceous age. The Pakora Formation lacks terrigenous continental detritus and is interpreted as a proximal base-of-slope apron related to rifting of the oceanic Ladakh Arc; (3). The Tectonic Melange (ocean ridge-type volcanics and recrystallised radiolarian cherts, interpreted as accreted oceanic crust. (4). The Bauma-Harel Group (structurally highest) is a thick succession (several km) of Ordovician and Carboniferous to Permian-Triassic, low-grade, mixed carbonate/siliciclastic sedimentary rocks that accumulated on the south-Asian continental margin. A structurally associated turbiditic slope/basinal succession records rifting of the Karakoram continent (part of Mega-Lhasa) from Gondwana. Red clastics of inferred fluvial origin ('molasse') unconformably overlie the Late Palaeozoic-Triassic succession and are also intersliced with other units in the suture zone. Reconnaissance further east (north of the Shyok River) indicates the presence of redeposited volcaniclastic sediments and thick acid tuffs, derived from nearby volcanic centres, presumed to lie within the Ladakh Arc. In addition, comparison with Lower Cretaceous clastic sediments (Maium Unit) within the Northern Suture Zone, west of the Nanga Parbat syntaxis (Hunza River) reveals notable differences, including the presence of terrigenous quartz-rich conglomerates, serpentinite debris-flow deposits and a contrasting structural history. The Shyok Suture Zone in the Skardu area is interpreted to preserve the remnants of a rifted oceanic back-arc basin and components of the Asian continental margin. In the west (Hunza River), a mixed volcanogenic and terrigenous succession (Maium Unit) is interpreted to record syn-deformational infilling of a remnant back-arc basin/foreland basin prior to suturing of the Kohistan Arc with Asia (75-90 Ma).

  7. Suture granuloma with false-positive finding on PET/CT after gastrectomy for gastric cancer.

    Science.gov (United States)

    Tsujita, Eiji; Ikeda, Yasuharu; Kinjo, Nao; Yamashita, Yo-Ichi; Kumagai, Reiko; Taguchi, Ken-Ichi; Yamaguchi, Shohei; Minami, Kazuhito; Yamamoto, Manabu; Morita, Masaru; Toh, Yasushi; Okamura, Takeshi

    2015-11-01

    This study is a case report on a 49-year-old woman who had a gastrectomy and lymphadenectomy for pStage IIIa gastric cancer. Shortly after a 12-month course of adjuvant chemotherapy, CT showed a nodule adjacent to the gallbladder. High (18) F-fluorodeoxyglucose accumulation was detected, with a standardized uptake value of 10. Therefore, laparoscopic excision was performed for diagnosis and treatment. The histopathological finding was suture granuloma. Suture granulomas with high standardized uptake values on PET scans are uncommon and often cause surgeons to provide an inaccurate diagnosis. Our study suggests that suture granuloma should be included in the differential diagnosis of a new or recurrent mass detected in patients with a history of prior surgery; however, surgeons must bear in mind that false-positive fluorodeoxyglucose-PET results can be observed in suture granuloma. PMID:26708585

  8. 77 FR 8117 - Medical Devices; Cardiovascular Devices; Classification of the Endovascular Suturing System

    Science.gov (United States)

    2012-02-14

    ... Testing Incompatibility with endograft Bench testing Migration or fracture of the endovascular Bench testing suture. Animal testing Clinical evaluation Imaging Incompatibility Bench testing Labeling... Testing Labeling Corrosion Bench testing Improper deployment or inability to deploy.. Bench testing...

  9. Bioinspired, mechanical, deterministic fractal model for hierarchical suture joints

    Science.gov (United States)

    Li, Yaning; Ortiz, Christine; Boyce, Mary C.

    2012-03-01

    Many biological systems possess hierarchical and fractal-like interfaces and joint structures that bear and transmit loads, absorb energy, and accommodate growth, respiration, and/or locomotion. In this paper, an elastic deterministic fractal composite mechanical model was formulated to quantitatively investigate the role of structural hierarchy on the stiffness, strength, and failure of suture joints. From this model, it was revealed that the number of hierarchies (N) can be used to tailor and to amplify mechanical properties nonlinearly and with high sensitivity over a wide range of values (orders of magnitude) for a given volume and weight. Additionally, increasing hierarchy was found to result in mechanical interlocking of higher-order teeth, which creates additional load resistance capability, thereby preventing catastrophic failure in major teeth and providing flaw tolerance. Hence, this paper shows that the diversity of hierarchical and fractal-like interfaces and joints found in nature have definitive functional consequences and is an effective geometric-structural strategy to achieve different properties with limited material options in nature when other structural geometries and parameters are biologically challenging or inaccessible. This paper also indicates the use of hierarchy as a design strategy to increase design space and provides predictive capabilities to guide the mechanical design of synthetic flaw-tolerant bioinspired interfaces and joints.

  10. A retrospective observational study comparing hair apposition technique, suturing and stapling for scalp lacerations

    OpenAIRE

    Ozturk, Derya; Sonmez, Bedriye Müge; Altinbilek, Ertugrul; Kavalci, Cemil; Engin Deniz ARSLAN; AKAY, Serhat

    2013-01-01

    Aim Scalp lacerations are commonly encountered in patients presenting to emergency department with trauma. Lacerations are repaired with suturing, stapling, adhesive tapes, and tissue adhesives. In this study, we aimed to compare the effectiveness of suturing, stapling, and hair apposition techniques used in repair of scalp lacerations in patients who presented to emergency department with scalp laceration. Materials and method After obtaining approval of local ethics committee, we examined t...

  11. Bioabsorbable Suture Anchor Migration to the Acromioclavicular Joint: How Far Can These Implants Go?

    OpenAIRE

    Medina, Giovanna; Garofo, Guilherme; D'Elia, Caio O.; Bitar, Alexandre C.; Castropil, Wagner; Schor, Breno

    2014-01-01

    Few complications regarding the use of bioabsorbable suture anchors in the shoulder have been reported. What motivated this case report was the unusual location of the anchor, found in the acromioclavicular joint which, to our knowledge, has never been reported so far. A 53-year old male with previous rotator cuff (RC) repair using bioabsorbable suture anchors presented with pain and weakness after 2 years of surgery. A suspicion of retear of the RC led to request of a magnetic resonance imag...

  12. Comperative analysis of unilateral cleft lip closure using absorbable and nonabsorbable sutures: a randomised clinical study

    Directory of Open Access Journals (Sweden)

    Abhay Nilkanth Datarkar

    2014-09-01

    Full Text Available Aim: Patients with cleft lip usually undergo multiple procedures that require hospitalization resulting in emotional stress to their family members. Young patients often require sedation or general anesthesia (GA for suture removal on a sensitive area to prevent disruption of the repair. In this study, we compared absorbable and nonabsorbable sutures for primary cleft lip repair. Methods: Patients with cleft lip who presented to Smile Train Unit, Child Hospital and Research Institute, Nagpur, India, were randomly assigned to two groups and underwent surgical repair using either Vicryl Rapid suture (Group 1 or Prolene suture (Group 2. Patients were followed up at 1 month, 6 months, and 1 year. Photographs of the patients were obtained at these visits and rated using a validated 100-mm cosmesis visual analogue scale (VAS by three people (social worker, surgeon, and patient's mother. A VAS score of 15 mm or greater was considered as clinically important difference. Results: A total of 60 patients were enrolled in this study, and they were equally divided into two groups. There was no difference in age, race, sex, wound length, number of sutures, and layered repair rates between the groups. The average age of the patient was 3 months. There was no significant difference in the rates of infection which was 6% in this study, wound dehiscence, and hypertrophic scar formation. No significant difference was found in cosmetic outcome in both the mean VAS score of 90.3 in Group 1 and 91.7 in Group 2. Conclusion: Absorbable sutures are a viable alternative to nonabsorbable sutures in the repair of primary cleft lip repair. We prefer absorbable sutures because they do not require removal under GA or sedation.

  13. Keratometric astigmatism after ECCE in eastern Nepal. Continuous versus interrupted sutures.

    OpenAIRE

    Sood Archana; Thakur Sanjay Kumar; Kumar Sandeep; Badhu Badri

    2003-01-01

    Purpose: The study aimed to compute and compare the keratometric astigmatism induced by wound closure with continuous and interrupted sutures in conventional extracapsular cataract extraction with intraocular lens implantation at a single centre in eastern Nepal. Methods: Sixty eyes of 60 patients were included in the study. All patients received conventional extracapsular cataract extraction and single piece modified C-loop posterior chamber intraocular lens. Thirty eyes were sutured with...

  14. Experimental studies on the influence of irradiation (60Co) on wound healing of colonic suture

    International Nuclear Information System (INIS)

    Effects of preoperative 60Co irradiation on wound healing of colonic suture in adult dogs of mixed breed were discussed. Wound healing 7 days after colonic suture was compared among dogs which received colonic suture immediately, or 3 days, or 7 days after the 60Co irradiation. As a result, there was not a big difference in their wound healing among these dogs, and disorders of wound healing were not found. Bursting pressure at sutured sites was always lower in irradiated dogs than controls. Recovery of the bursting pressure was 2 days slower in irradiated dogs than non-irradiated dogs for 7 days after the suture. Bursting pressure was the lowest on the 3rd day after the suture in both groups. As to fine changes in irradiated dogs, appearance of recommunicating phenomena in blood vessels, delay of a decrease in avascular regions, delay of granulation, and hypertrophy of vascular walls seemed to be influenced by 60Co irradiation, but there was not a big difference in these results between irradiated and non-irradiated dogs. An increase in postoperative concentration of hydroproline tended to be little lower in irradiated dogs than controls, which seemed to be influenced by the 60Co irradiation. This result was also suggested from delay of granulation and remaining inflammations. Effects of 60Co irradiation on wound healing of colonic suture seemed to be slight generally, because ruptured suture scarecely occurred in the irradiated dogs. When doses used in this experiment were calculated roughly by Ellis's method, irradiation of 60Co seemed not to influence seriously wound healing if the total of 2,000 to 2,500 rad was irradiated in 8 to 10 doses to human colon. (Tsunoda, M.)

  15. A single centre comparative study of laparoscopic mesh rectopexy versus suture rectopexy

    Directory of Open Access Journals (Sweden)

    Manash Ranjan Sahoo

    2014-01-01

    Full Text Available Aim: The aim of our study is to compare the results of laparoscopic mesh vs. suture rectopexy. Materials and Methods: In this retrospective study, 70 patients including both male and female of age ranging between 20 years and 65 years (mean 42.5 yrs were subjected to laparoscopic rectopexy during the period between March 2007 and June 2012, of which 38 patients underwent laparoscopic mesh rectopexy and 32 patients laparoscopic suture rectopexy. These patients were followed up for a mean period of 12 months assessing first bowel movement, hospital stay, duration of surgery, faecal incontinence, constipation, recurrence and morbidity. Results: Duration of surgery was 100.8 ± 12.4 minutes in laparoscopic suture rectopexy and 120 ± 10.8 min in laparoscopic mesh rectopexy. Postoperatively, the mean time for the first bowel movement was 38 hrs and 40 hrs, respectively, for suture and mesh rectopexy. Mean hospital stay was five (range: 4-7 days. There was no significant postoperative complication except for one port site infection in mesh rectopexy group. Patients who had varying degree of incontinence preoperatively showed improvement after surgery. Eleven out of 18 (61.1% patients who underwent laparoscopic suture rectopexy as compared to nine of 19 (47.3% patients who underwent laparoscopic mesh rectopexy improved as regards constipation after surgery. Conclusion: There were no significant difference in both groups who underwent surgery except for patients undergoing suture rectopexy had better symptomatic improvement of continence and constipation. Also, cost of mesh used in laparoscopic mesh rectopexy is absent in lap suture rectopexy group. To conclude that laparoscopic suture rectopexy is a safe and feasible procedure and have comparable results as regards operative time, morbidity, bowel function, cost and recurrence or even slightly better results than mesh rectopexy.

  16. Immunostimulatory sutures that treat local disease recurrence following primary tumor resection

    OpenAIRE

    Intra, Janjira; Zhang, XueQing; Williams, Robin L.; Zhu, Xiaoyan; Anthony D. Sandler; Salem, Aliasger K.

    2011-01-01

    Neuroblastoma is a common cancer of childhood that often results in progressive minimal residual disease after primary tumor resection. Cytosine-phosphorothioate-guanine oligonucleotides (CpG ODN) have been reported to induce potent anti-tumor immune responses. In this paper, we report on the development of a CpG ODN loaded suture that can close up the wound following tumor excision and provide sustained localized delivery of CpG ODN to treat local disease recurrence. The suture was prepared ...

  17. Vaginal cuff dehiscence in laparoscopic hysterectomy: influence of various suturing methods of the vaginal vault

    OpenAIRE

    Blikkendaal, M. D.; Twijnstra, A. R. H.; Pacquee, S. C. L.; Rhemrev, J. P. T.; Smeets, M. J. G. H.; de Kroon, C D; Jansen, F.W.

    2012-01-01

    Vaginal cuff dehiscence (VCD) is a severe adverse event and occurs more frequently after total laparoscopic hysterectomy (TLH) compared with abdominal and vaginal hysterectomy. The aim of this study is to compare the incidence of VCD after various suturing methods to close the vaginal vault. We conducted a retrospective cohort study. Patients who underwent TLH between January 2004 and May 2011 were enrolled. We compared the incidence of VCD after closure with transvaginal interrupted sutures ...

  18. Suture-related keratitis following cataract surgery caused by methicillin-resistant Staphylococcus aureus

    OpenAIRE

    Tarabishy, Ahmad B.; Steinemann, Thomas L

    2010-01-01

    Ahmad B Tarabishy1, Thomas L Steinemann21Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA; 2Cornea and External Eye Disease, MetroHealth Medical Center, Case Western Reserve University, Cleveland, OH, USAAbstract: A 54-year old-man presented with a two-day history of severe pain and decreased vision. Examination revealed a corneal ulcer associated with a loose suture from cataract surgery done approximately two years ago. The suture was removed and the patient was started on topic ant...

  19. Arthroscopic Posterior Bone Block Procedure: A New Technique Using Suture Anchor Fixation

    OpenAIRE

    Boileau, Pascal; Hardy, Marie-Béatrice; McClelland, Walter B.; Thélu, Charles-Edouard; Schwartz, Daniel G.

    2013-01-01

    We present a novel all-arthroscopic technique of posterior shoulder stabilization that uses suture anchors for both bone block fixation and capsulolabral repair. The bone graft, introduced inside the glenohumeral joint through a cannula, is fixed with 2 suture anchors. The associated posteroinferior capsulolabral repair places the bone block in an extra-articular position. In this article we present the detailed arthroscopic technique performed in a consecutive series of 15 patients and repor...

  20. Free Gingival Grafting; Epiglu VS. Silk Thread Suturing: A Comparative Study

    OpenAIRE

    M. Paknejad; Y. Soleymani Shayesteh; A. Esmaielieh

    2004-01-01

    Statement of the Problem: The routine procedure for immobilization of free gingival graft (FGG) is suturing. Due to the successful application of tissue adhesives their employment has also become the subject of interest.Purpose: The aim of present clinical trial was to compare using Epiglu (E.g) versus silk thread suturing in FGG.Materials and Methods: This study was a split mouth clinical trial. The study group comprised of 12 patients with symmetrical loss of attached gingiva whom were refe...

  1. Randomized clinical trial of self-gripping mesh versus sutured mesh for Lichtenstein hernia repair

    DEFF Research Database (Denmark)

    Jorgensen, L N; Sommer, Thorbjørn; Assaadzadeh, S; Strand, L; Dorfelt, A; Hensler, M; Rosenberg, J

    2013-01-01

    BACKGROUND: Many patients develop discomfort after open repair of a groin hernia. It was hypothesized that suture fixation of the mesh is a cause of these symptoms. METHODS: This patient- and assessor-blinded randomized multicentre clinical trial compared a self-gripping mesh (Parietene Progrip(®) ) and sutured mesh for open primary repair of uncomplicated inguinal hernia by the Lichtenstein technique. Patients were assessed before surgery, on the day of operation, and at 1 and 12 months after s...

  2. Randomized clinical trial of self-gripping mesh versus sutured mesh for Lichtenstein hernia repair

    DEFF Research Database (Denmark)

    Jorgensen, L N; Sommer, T; Assaadzadeh, S; Strand, L; Dorfelt, A; Hensler, Margaret Kathryn; Rosenberg, J; Sommer, Thorbjørn

    2012-01-01

    BACKGROUND: Many patients develop discomfort after open repair of a groin hernia. It was hypothesized that suture fixation of the mesh is a cause of these symptoms. METHODS: This patient- and assessor-blinded randomized multicentre clinical trial compared a self-gripping mesh (Parietene Progrip(®) ) and sutured mesh for open primary repair of uncomplicated inguinal hernia by the Lichtenstein technique. Patients were assessed before surgery, on the day of operation, and at 1 and 12 months after s...

  3. Sutural loosening and skeletal flexibility during growth: determination of drop-like shapes in sea urchins.

    OpenAIRE

    Johnson, Amy S.; Ellers, Olaf; Lemire, Jim; Minor, Melissa; Leddy, Holly A

    2002-01-01

    The shape of sea urchins may be determined mechanically by patterns of force analogous to those that determine the shape of a water droplet. This mechanical analogy implies skeletal flexibility at the time of growth. Although comprised of many rigid calcite plates, sutural collagenous ligaments could confer such flexibility if the sutures between plates loosened and acted as joints at the time of growth. We present experimental evidence of such flexibility associated with weight gain and grow...

  4. Keratometric astigmatism after ECCE in eastern Nepal. Continuous versus interrupted sutures.

    Directory of Open Access Journals (Sweden)

    Sood Archana

    2003-01-01

    Full Text Available Purpose: The study aimed to compute and compare the keratometric astigmatism induced by wound closure with continuous and interrupted sutures in conventional extracapsular cataract extraction with intraocular lens implantation at a single centre in eastern Nepal. Methods: Sixty eyes of 60 patients were included in the study. All patients received conventional extracapsular cataract extraction and single piece modified C-loop posterior chamber intraocular lens. Thirty eyes were sutured with continuous (Group 1 and 30 eyes with interrupted sutures (Group 2. The results were analysed by the unpaired student?s t-test. Results: At the end of 6 weeks, Group 1 patients had significantly higher astigmatism (3.53 ± 2.19D compared to Group 2 patients (1.7 ± 1.35. A majority of patients in both groups had with-the-rule astigmatism throughout the postoperative period. Conclusion: Interrupted sutures cause less astigmatism than continuous suture. The factors responsible for high astigmatism in continuous sutures call for further analysis.

  5. Cranial Suture Closure in Domestic Dog Breeds and Its Relationships to Skull Morphology.

    Science.gov (United States)

    Geiger, Madeleine; Haussman, Sinah

    2016-04-01

    Bulldog-type brachycephalic domestic dog breeds are characterized by a relatively short and broad skull with a dorsally rotated rostrum (airorhynchy). Not much is known about the association between a bulldog-type skull conformation and peculiar patterns of suture and synchondrosis closure in domestic dogs. In this study, we aim to explore breed-specific patterns of cranial suture and synchondrosis closure in relation to the prebasial angle (proxy for airorhynchy and thus bulldog-type skull conformation) in domestic dogs. For this purpose, we coded closure of 18 sutures and synchondroses in 26 wolves, that is, the wild ancestor of all domestic dogs, and 134 domestic dogs comprising 11 breeds. Comparisons of the relative amount of closing and closed sutures and synchondroses (closure scores) in adult individuals showed that bulldog-type breeds have significantly higher closure scores than non-bulldog-type breeds and that domestic dogs have significantly higher closure scores than the wolf. We further found that the prebasial angle is significantly positively correlated with the amount of closure of the basispheno-presphenoid synchondrosis and sutures of the nose (premaxillo-nasal and maxillo-nasal) and the palate (premaxillo-maxillary and interpalatine). Our results show that there is a correlation between patterns of suture and synchondrosis closure and skull shape in domestic dogs, although the causal relationships remain elusive. Anat Rec, 299:412-420, 2016. © 2016 Wiley Periodicals, Inc. PMID:26995336

  6. A clinical study on the influence of suturing material on oral wound healing

    Directory of Open Access Journals (Sweden)

    Gazivoda Dragan

    2015-01-01

    Full Text Available Background/Aim. Suture materials play an important role in healing, enabling reconstruction and reassembly of tissue separated by the surgical procedure or trauma, and at the same time facilitating and promoting healing and hemostasis. Suture materials are used daily in oral surgery, and are considered to be substances most commonly implanted in human body. The aim of this clinical study was to examine the speed of wound healing and complications incidence, after the use of three different absorbable synthetic suture materials in oral surgery (catgut, Dexon and Vicryl rapide, and to ascertain which one is the most suitable for oral surgery. Methods. The study was conducted on 96 patients undergoing root resection or surgical extraction of third molars. Each of the suture materials (catgut, Dexon and Vicryl rapide was used for 8 root resections and 8 surgical third molar extractions in the maxilla, as well as in the mandible (a total of 32 surgical interventions for each suture material. Results. The faster wound healing was obtained with Vicryl rapide compared to other two suturing material tested. There was no significant difference regarding the presence of local reaction in all the three groups of patients on the 21st postoperative day. Conclusion. The results of our clinical study point out that Vycrilrapid contributes more than catgut or Dexon to faster healing of human wounds, with fewer incidences of wound dehiscence and milder local reactions.

  7. Preparation and Characterization of Coir, Luffa Reinforced Polypropylene Composites

    Directory of Open Access Journals (Sweden)

    S.Tharaknath

    2014-10-01

    Full Text Available Natural fibres have been used to reinforce materials for over 3,000 years. More recently they have been employed in combination with plastics. Many types of natural fibres have been investigated for use in plastics including coir, luffa, flax, hemp, jute, sisal, and banana. Natural fibres have the advantages that they are renewable resources and have marketing appeal. These agricultural wastes can be used to prepare fibre reinforced polypropylene composites for commercial use. Application of composite materials to structures have presented the need for the engineering analysis this work focuses on the fabrication of polymer matrix composites by using natural fibres like coir, and luffa which are abundant nature in desired shapes by the help of various structures of patterns and calculating its material characteristics (tensile strength, flexural modulus, flexural rigidity, hardness number,% gain of water by conducting tests like tensile test, flexural test, hardness test, water absorption test, impact test, density test, sem analysis and their results are measured on sections of the material and make use of the natural fibre reinforced polypropylene composite material for automotive seat shell manufacturing.

  8. Investigation of Fibres Migration in Cotton/Polypropylene Blended Yarn

    Directory of Open Access Journals (Sweden)

    Dzmitry RYKLIN

    2014-09-01

    Full Text Available This study is devoted to theoretical and experimental research of fibres migration in blended yarns. A hypothesis states that due to fibres migration their tension in yarn becomes equal. On the basis of that hypothesis, we identified the factors that affect the migration. The main factors influencing are differences in Young's modulus and density of fibres. Simulating the fibres migration we obtained the formulae for determining the proportion of fibres in the external and inner layers of blended yarn. These formulae were proved by analysis of cross-section of cotton/polypropylene yarn. Results of blended yarn processing in knitting showed that migration of polypropylene fibres in direction to the yarn surface leads to significant increase of yarn breakages due to growth of its friction coefficient. Reduction of the input yarn tension by 10 % – 15 % helped to stabilize the process of knitting. It was found that the usage of theoretical information about fibres migration allows to draw conclusions about the necessity of adjustments to settings of subsequent processing of blended yarns. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4610

  9. Photodegradation of a polypropylene filled with lanthanide complexes

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    Valérie Massardier

    2015-01-01

    Full Text Available Abstract This research aims at studying the photodegradation of a polypropylene formulation filled with lanthanide complexes. These complexes can be used as tracers for the identification of polymer materials in order to facilitate an high speed automatic sorting of plastic wastes for an economically efficient recycling. By paying attention to the evolution of carbonyl absorption bands in FTIR spectra, it is observed that the addition of lanthanide complexes into our formulation improves UV stability of polypropylene by reducing the extent of photo-degradation. Furthermore, TG analyses show that the traced blends can maintain better thermal properties, after irradiation. A significant increase of the crystallinity degree and a decrease of the melting temperature are more pronounced for the unfilled UV–irradiated PP. This might result from chemi-crystallization that can occur when chain entanglements are broken as a result of chain scissions. From SEM analyses, it is observed that the severity of surface cracks induced by photo degradation is reduced for filled PP. The mechanical tests are in agreement with this result and show a fundamental change in the behavior of the as-exposed blends from a ductile to a brittle material.

  10. Aging effects of polypropylene used in heating systems

    International Nuclear Information System (INIS)

    The ageing effects of polypropylene targets used in heating systems were investigated using the nuclear reaction analysis (NRA) technique. Deuterium beams of energies 900, 1200 and 1500 keV, supplied from the University of Jordan Van de Graaff accelerator, were employed. Different working times between 1 and 6 years were investigated in addition to a new fresh sample which was considered as standard. The reactions resulting from 12C(d,p)13C, 16O(d,p1)17O and 14N(d,?1)12C were monitored. The oxygen and nitrogen concentrations data reveal similar behaviour for both elements. The initial concentration of both quantities resulting from fusion, processing and storage times decreases and then gradually increases to reach higher levels than those initially, as the working time is increased. A model, based on mass transfer of air-oxygen and nitrogen and solubility of polypropylene to both elements, was proposed to explain our observation. The uptake of these light impurities and their presence at high concentration levels in the thermopipes material, in addition to microstructural effects, are responsible for the degradation of many of its observed properties. The main effect was demonstrated by the influence of several parameters on strength and embrittlement. (Author)

  11. Acoustic properties of polypropylene composites reinforced with stone groundwood

    Directory of Open Access Journals (Sweden)

    Joan Pere López

    2012-11-01

    Full Text Available Currently, acoustic isolation is one of the problems raised with building construction in Spain. The publication of the Basic Document for the protection against noise of the Technical Building Code has increased the demand of comfort for citizens. This has created the need to seek new composite materials that meet the new required acoustical building codes. In this paper we report the results of the newly developed composites that are able to improve the acoustic isolation of airborne noise. These composites were prepared from polypropylene (PP reinforced with mechanical pulp fibers from softwood (Pinus radiata. Mechanical and acoustical properties of the composites from mechanical pulp (MP and polypropylene (PP have been investigated and compared to fiberglass (FG composites. MP composites had lower tensile properties compared with FG composites, although these properties can be improved by incorporation of a coupling agent. The results of acoustical properties of MP composites were reported and compared with the conventional composites based on fiberglass and gypsum plasterboards. Finally, we suggest the application of MP composites as a light-weight building material to reduce acoustic transmitions.

  12. Chemical modification of polypropylene induced by high energy carbon ions

    International Nuclear Information System (INIS)

    Polypropylene was irradiated with 12C+ ions of 3.6 and 5.4 MeV energy using 3 MV Pelletron. The spectral changes owing to ion bombardment were investigated by UV-VIS and Fourier-transform infrared (FTIR) spectroscopy. A gradual increase in absorbance was observed around visible and near visible region with increase in fluence of bombarding ions. The difference absorption spectra show formation of chromophoric groups with wavelength maximum near 380 nm at lower fluence, but at high fluence a shift in peak is observed. The chromophoric groups are likely to be the extended conjugated polyene system and the red shift in peak position at high fluence may be attributed to the greater degree of conjugation. The formation of unsaturated linkage is confirmed by the FTIR spectra with observed stretching band around 1650 cm-1 and its intensity was found to increase with increase in ion fluence studied. The gases (in the range 2-80 amu) which were evolved due to interaction of polypropylene with 12C+ ions were measured with Residual Gas Analyzer (RGA). A large number of gaseous components were detected. This shows that polymer chains break into some smaller fragments which concomitantly leads to extended conjugation

  13. Investigation of physical and chemical properties of polypropylene hybrid nanocomposites

    International Nuclear Information System (INIS)

    Highlights: → Effect of morphology and properties of PP hybrid nanocomposites was investigated. → Intercalated-exfoliated structures were in the system. → Significant improvement of physical and chemical properties in hybrid nanocomposites. → PP hybrid nanocomposites showed good thermal stability. -- Abstract: Hybrid nanocomposites fabricated based on an optimized physical and chemical properties modified polypropylene (PP)/polypropylene grafted maleic anhydride (PP-g-MA) with varied concentrations (1-7 wt% at a step of 2 wt%) of organoclay, montmorillonite (MMT). The morphology of the nanocomposites was studied by scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). It was found that partly intercalated and partly exfoliated structure (intercalated-exfoliated structures) existed in the system. The degree of exfoliation is a key factor to determine the reinforcement efficiency. The ratio of exfoliation to intercalation plays an important role in determining the properties of PP nanocomposites and only completely exfoliated silicate layers can significantly improve the properties. PP hybrid nanocomposites showed good thermal stability in the thermogravimetric analysis (TGA). Introduction of ∼3% MMT in the nanocomposites increased the onset temperature of degradation by 27.5 oC compared to that of pure PP, while the 5 wt% MMT resulted the maximum hardness in these nanocomposites. The solvent resistance of PP hybrid nanocomposites slightly increased with increasing the clay content.

  14. Radiation Modification of Polypropylene Waste for Using as Electrolyte Membranes

    International Nuclear Information System (INIS)

    Graft copolymerization of styrene onto polypropylene (PP) and waste polypropylene (WPP) films has been carried out by means of γ-irradiation. The parameters may affect the grafting yield such as irradiation dose, type of solvent, inhibitor concentration, irradiation atmosphere and monomer concentration were optimized. The grafted films were then treated with chlorosulfonic acid to introduce sulfonic group as a high proton exchange moiety. The obtained membranes were characterized by using fourier transform infrared spectroscopy (FTIR), and studying their swelling behavior, thermal and mechanical properties. The electrical properties of the prepared membranes were evaluated as a function of degree of grafting, hydration number and their ionic conductivity. The results showed that the ionic conductivity of the WPP increases from 6 x 10-10 to 2.8 multiplication sign 10-2 S/ cm and for PP increases from 7x10-10 to 4.1x10-3 S/cm by changing the grafting degree. The chemical, physical and electrical characteristics of the prepared membranes recommend these membranes as potential candidate for proton exchange membrane fuel cell (PEMFC) applications

  15. Susceptibility to scratch surface damage of wollastonite- and talc-containing polypropylene micrometric composites

    International Nuclear Information System (INIS)

    The paper describes the effect of wollastonite and talc on the scratch deformation behavior of low and high crystallinity polypropylenes under identical test conditions. The vertical resolution of atomic force microscopy and lateral resolution of scanning electron microscopy is utilized to examine the characteristics of scratch damage. Contrary to the expectations that high crystallinity and stiffness of polypropylene composites should increase resistance to scratch deformation, the susceptibility to mechanical deformation depends on bonding of mineral particles to the polymer matrix. Scratch deformed regions in neat polypropylenes were free of voids and grooves, while reinforced-polypropylenes exhibited voids and debonding/detachment of filler particles. The severity of plastic deformation in reinforced polypropylenes is a function of debonding/detachment of mineral particles, which is comparatively more for talc-reinforced polypropylenes than wollastonite-reinforced polypropylenes because of the layered structure of talc that encourages delamination. Usage of coating and coupling agents improved the resistance to scratch deformation by promoting adhesion and bonding between the reinforcement and matrix

  16. TENSILE STRENGTH CHARACTERISTICS OF POLYPROPYLENE COMPOSITES REINFORCED WITH STONE GROUNDWOOD FIBERS FROM SOFTWOOD

    Directory of Open Access Journals (Sweden)

    Joan P. López,

    2012-06-01

    Full Text Available The behavior of stone groundwood / polypropylene injection-molded composites was evaluated with and without coupling agent. Stone groundwood (SGW is a fibrous material commonly prepared in a high yield process and mainly used for papermaking applications. In this work, the use of SGW fibers was explored as a reinforcing element of polypropylene (PP composites. The surface charge density of the composite components was evaluated, as well as the fiber’s length and diameter inside the composite material. Two mixing extrusion processes were evaluated, and the use of a kinetic mixer, instead of an internal mixer, resulted in longer mean fiber lengths of the reinforcing fibers. On the other hand, the accessibility of surface hydroxyl groups of stone groundwood fibers was improved by treating the fibers with 5% of sodium hydroxide, resulting in a noticeable increase of the tensile strength of the composites, for a similar percentage of coupling agent. A new parameter called Fiber Tensile Strength Factor is defined and used as a baseline for the comparison of the properties of the different composite materials. Finally the competitiveness of stone groundwood / polypropylene / polypropylene-co-maleic anhydride system, which compared favorably to sized glass-fiber / polypropylene GF/PP and glass-fiber / polypropylene / polypropylene-co-maleic anhydride composite formulations, was quantified by means of the fiber tensile strength factor.

  17. Effects of surface modification of talc on mechanical properties of polypropylene/talc composites

    Science.gov (United States)

    Liu, Keyan; Stadlbauer, Wolfgang; Zitzenbacher, Gernot; Paulik, Christian; Burgstaller, Christoph

    2016-03-01

    Low compatibility of polymer matrix and dispersed filler negatively affects the performance of polymeric composites. In order to improve the adhesion between the components in a compound the polymer matrix or/and the filler particles should be modified with a compatibilizer or/and a coupling agent. An overview of our current research on the effect of the addition of silane treated and untreated talc powders on the mechanical properties of polypropylene/talc composites is presented in this paper. Different silane coupling agents (3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane) were used to improve the adhesion at the surface of talc powders. Maleic anhydride grafted polypropylene was utilized to increase the adhesion between the polypropylene matrix and talc powders. The content of maleic anhydride grafted polypropylene (MA-g-PP) was varied between 1 and 5 wt% in polypropylene/talc composites. The surface modification of talc powders has a significant effect on the interfacial structure and the mechanical properties such as tensile strength and impact strength of polypropylene/talc composites. The experiments show that polypropylene grafted with maleic anhydride together with silane surface treatment exhibits the highest potential for improvements in this field.

  18. Investigation of the nanostructure and mechanical properties of polypropylene/polyamide 6/layered silicate ternary nanocomposites

    International Nuclear Information System (INIS)

    This work aims to investigate the structure-property relationship in ternary nanocomposites consisting of polypropylene as the matrix, nanoclay as the reinforcement and polyamide 6 as the intermediate phase. In this regard, composites of polypropylene/organoclay, polyamide/organoclay, blends of polypropylene/polyamide, and ternary nanocomposites of polypropylene/polyamide/layered silicate with and without compatibilizer were produced via melt compounding. Nanostructure was investigated by wide-angle X-ray diffraction and transmission electron microscopy. Scanning electron microscopy was employed to study the microstructure. Modulus of elasticity and yield strength were measured by uniaxial tensile test. Results show that silicate layers can only be observed inside polyamide particles. Moreover, polypropylene was unable to intercalate the grade of organoclay used in this study. While polyamide/organoclay system exhibited an exfoliated structure, the nanostructure of ternary nanocomposites was chiefly intercalated, due to the high concentration of silicate layers inside polyamide particles. Incorporation of organoclay into the polypropylene/polyamide system was seen to have a noticeable effect on the shape and size of polyamide particles. In addition, elastic modulus and yield strength were observed to be directly affected by incorporation of nanoclay and compatibilizer into the polypropylene matrix, respectively. The simultaneous presence of the two constituents in the system resulted in samples with superior mechanical properties in the elastic as well as the plastic deformation regime.

  19. Toughening of polypropylene with β-nucleated thermoplastic vulcanizates based on polypropylene/ethylene–propylene–diene rubber blends

    International Nuclear Information System (INIS)

    Highlights: • We designed and prepared β nucleated thermoplastic vulcanizates. • We adopted the β nucleated TPV to toughen polypropylene. • Greatly improved toughness of iPP, limited loss in strength and rigidity was achieved. • A toughening mechanism was proposed. - Abstract: A series of dynamically vulcanized isotactic polypropylene (PP)/ethylene–propylene–diene rubber thermoplastic vulcanizates (TPVs) containing different content of β-nucleating agent (β-NA) were prepared and introduced into isotactic PP matrix as a toughening agent. The effect of β-nucleated TPVs (β-TPVs) on the toughness and other properties of PP were studied. Differential scanning calorimetry and wide-angle X-ray diffraction results indicated that the β-crystallinity and the relative content of β-phase in β-TPVs samples and the toughened blends increased with the content of β-NA increasing. The notched impact strength of PP toughened by β-TPVs, with limited loss in the tensile strength and rigidity, showed an almost linear increase with increasing β-NA content. Especially when the content of β-NA was 0.5 wt%, the impact strength of the toughened blends was ten times more than that of pure PP. The toughening mechanism based on classical rubber toughening mechanisms was discussed and a synergic toughening mechanism was proposed

  20. Deep suture zone in the North Barents Basin

    Science.gov (United States)

    Butsenko, Viktor; Kireev, Artem; Piskarev, Alexey; Savin, Vasily; Smirnov, Oleg

    2015-04-01

    Study of sedimentary basin evolution is a part of research for the forecast of oil and gas capacity of the North Barents shelf. Maps of potential fields anomalies are compiled on the basis of the latest geophysical databases, structural maps of the seismic horizons are analyzed, the location of sources of potential fields anomalies are calculated, 3D density and magnetic models of Earth's crust are constructed. Six seismic complexes are allocated in sedimentary cover structure: Devonian - Lower Carboniferous, Upper Carboniferous - Lower Permian, Mid Permian - Lower Triassic, Triassic - Lower Jurassic, Upper Jurassic - Lower Cretaceous, Lower Cretaceous - Quaternary. The research of lateral changes of allocated layers thickness gives an idea of sedimentation in the region on various time intervals. The structural and tectonic scheme of the region is made after analysis of new geologic-geophysical materials. Contact zones of heterogeneous blocks of the crystalline basement are marked, disjunctive dislocations in a sedimentary cover and the upper crust, and also zones of increase of sediments thickness in various seismic complexes are designated. The deep suture zone delimiting Mesozoic and Paleozoic sedimentary basins has the most important geological value among disjunctive zones of the region. This zone stretches along the Admiralty Arch in East part of the North Barents shelf and is marked by negative magnetic anomaly 30-50 km wide. In view of special tectonic value of the suture zone marked by this anomaly we have calculated the 3D magnetic crust model. The sedimentary layers of a model section is based on seismic data. As a result of modeling the studied anomaly of a magnetic field can be approximated by the block of basement rocks of the lowered magnetization (1.2 A/m). The surface of this block is located in a zone of anomaly at a depth of 12-14 km. The asymmetry of anomaly is accounted by an inclination to East of the borders of the block with low magnetization. Calculated basement magnetization is 1.9 A/m to the West from an anomaly zone that is a characteristic for many igneous and metamorphic rocks of the diorite composition. Magnetization of the basement formations sharply increases to 3.6 A/m to the East. Similar values of magnetization are characterized basalts and dolerites, and also many metamorphic rocks of the basic and ultrabasic composition. Thus, the simulated magnetic field anomaly not only corresponds to limits of the heterochronous sedimentary basins, but also shows the border between two heterogeneous basement blocks. "Bright spot" anomalies are marked out on seismic sections. Bright spots are mainly located near the zone of negative magnetic anomaly along the East part of the North Barents Basin. The AVO analysis of the anomalies of the seismic recording has allowed to allocate possible hydrocarbon reservoirs and to subdivide them into the gas-saturated and oil-gas-saturated.

  1. Editor's Choice - A Randomized Controlled Trial of the Fascia Suture Technique Compared with a Suture-mediated Closure Device for Femoral Arterial Closure after Endovascular Aortic Repair

    DEFF Research Database (Denmark)

    Larzon, T; Roos, H; Gruber, G; Henrikson, O; Magnuson, A; Falkenberg, M; Lönn, L; Norgren, L

    2015-01-01

    OBJECTIVES: The aim was to investigate whether the fascia suture technique (FST) can reduce access closure time and procedural costs compared with the Prostar technique (Prostar) in patients undergoing endovascular aortic repair and to evaluate the short- and mid-term outcomes of both techniques...

  2. Técnica de suturas ajustables: Resultados Technique of adjustable sutures: Results

    Directory of Open Access Journals (Sweden)

    Lourdes R. Hernández Santos

    2001-06-01

    Full Text Available Se realizó un estudio sensorial y motor preoperatorio y posoperatorio a 84 pacientes que acudieron a la consulta de Visión Binocular con el diagnóstico de estrabismo horizontal a partir de los 13 años de edad. El método estadístico utilizado fue "t" o Chi cuadrado. Nos trazamos como objetivo determinar los resultados posoperatorios de la cirugía de estrabismo realizada con la técnica de suturas ajustables, que fueron los siguientes: el 61 % de los pacientes con exotropía y el 71,4 % con el diagnóstico de exotropía se encontraban en ortotropía a los 6 meses de la intervención. El 71,4 % de los pacientes con esotropía y el 83,3 % con el diagnóstico de esotropía se encontraban en ortotropía al año de la intervención. Esta técnica quirúrgica permite la modificación de la desviación en el posoperatorio inmediato.A preoperative and postoperative sensorial and motor study was conducted among 84 patients who received attention at the consultation room of Binocular Vision with the diagnosis of horizontal strabismus from the age of 13 years old on. The statistical method used was "t" or chi square test. Our objective was to determine the postoperative results of the strabismus surgery performed by the technique of adjustable sutures. The results were as follows: 61 % of the patients with exotropia and 71.4 % with the diagnosis of exotropia were in orthotropia 6 months after the operation. 71.4 % of the patients with exotropia and 83.3 % with the diagnosis of exotropia were in orthotropia a year after the operation. This surgical technique allows the modification of the deviation in the immediate postoperative.

  3. Comparison of rheological and mechanical properties of modified polypropylene - short glass fiber composites

    International Nuclear Information System (INIS)

    Short glass fiber (SGF) reinforced composite materials were principally fabricated using polypropylene (PP) as thermo-plastic matrix. Short glass fiber and polypropylene frequently suffer from lack of adequate fiber-matrix adhesion. This problem was addressed by grafting polypropylene (PP) with maleic anhydride (MA) in the presence of benzyl peroxide (BPO) as an initiator. The results revealed that by increasing fiber contents from 5 to 40 %, tensile strength increases while elongation at break decreases. Rheological behavior was found to be pseudoplastic, whereas viscosity increases by increasing SGF contents. A decrease in die swell was observed with increase in SGF contents. (author)

  4. Effect of volume fraction of Polypropylene Fiber on Mechanical Properties of Concrete

    Directory of Open Access Journals (Sweden)

    R. S. Rajguru,

    2014-06-01

    Full Text Available In this study, the result of polypropylene fiber on mechanical properties of concrete is studied. Polypropylene fibers of 12mm cut length and 6 denier were added at volume fraction of 0%, 0.25%, 0.50%, 0.75% & 1 %.The cube, cylinder and beams wear tested under two point loads on UTM. The results showed that the addition of polypropylene fiber significantly improved the compressive strength, split tensile strength, flexural strength, reserve strength and ductility of fiber reinforced concrete.

  5. Estudo comparativo, em cães, entre a anastomose esôfago-esofágica cervical em dois planos de sutura e a em um plano único extramucoso Study in dogs comparing esophagus-esophageal cervical anastomosis in two planes of suture versus a single extramucosal plane

    Directory of Open Access Journals (Sweden)

    Amaury José Teixeira Nigro

    1997-03-01

    Full Text Available O objetivo é comparar a eficácia entre as anastomoses esôfago-esofágicas cervicais em dois planos de sutura com as feitas em um plano único extramucoso. Utilizou-se 60 cães, sadios, sem raça definida, de ambos os sexos, com peso médio de 15 kg. Foram separados em dois grupos iguais: no GRUPO I será feita a anastomose em dois planos de sutura e, no GRUPO II, a em um plano único extramucoso. Cada grupo foi subdividido em 3 subgrupos iguais, e para cada um deles foi estabelecido um determinado período de observação pós-operatório (PO de 7, 14 e 30 dias, respectivamente. As suturas foram feitas sempre com fio de polipropileno 4 zeros. Avaliou-se a incidência de complicações pós-operatórias imediatas e tardias e às características histológicas da cicatrização de cada tipo de anastomose. A análise estatística dos dados coletados permitiu verificar que na anastomose esôfago-esofágica cervical executada em um plano único extramucoso a porcentagem de fistulas (13,6%, e de estenoses (30% ao nível da zona de sutura foi significantemente menor do que a observada na sutura realizada em dois planos de sutura em que as porcentagens foram de (26,7% e (63,4%, respectivamente. A cicatrização das estruturas da parede esofágica ao nível da anastomose também foi significantemente melhor na anastomose em plano único extramucoso do que na em dois planos de sutura. Os resultados observados permitiram concluir que a anastomose em plano único extramucoso é mais eficaz do que a executada em dois planos de sutura.The objective of our study was to compare the efficacy of two types of cervical esophagus-esophageal anastomoses: two planes of suture versus a single extramucosal suture. Sixty healthy mongrel dogs of both sexes with a medium body weight of 15 kg. Were separated into two groups. Group one: anastomosis using two planes of suture; and Group two: anastomosis using one plane of extramucosal suture. Each group was divided into three subgroups based on post-operative time periods: 7, 14 and 30 days. Polypropylene 4-0 sutures were used in all anastomoses. The incidence of early and late post-operative complications and histological characteristics of the healing process at the site of the anastomoses were evaluated. Statistical analyses of the data collected permitted verification that the cervical esophagus-esophageal anastomoses done by only the extramucosal suture showed an incidence of 13.6% fistula and 30% stenosis at the level of the suture zone, which was significantly lower as compared to that observed in the two plane suture repair group where the percentages were 26.7 and 63.4 respectively. The healing of the structure of the esophageal wall at the level of the anastomosis was also significantly improved in the single plane extramucosal anastomosis group as compared to the two plane suture group. The observed results permitted conclusion that the extramucosal anastomosis in a single plane is more effícacious than that executed in two suture planes.

  6. Estudo comparativo, em cães, entre a anastomose esôfago-esofágica cervical em dois planos de sutura e a em um plano único extramucoso / Study in dogs comparing esophagus-esophageal cervical anastomosis in two planes of suture versus a single extramucosal plane

    Scientific Electronic Library Online (English)

    Amaury José Teixeira, Nigro; Neil Ferreira, Novo; Yara, Juliano.

    1997-03-01

    Full Text Available O objetivo é comparar a eficácia entre as anastomoses esôfago-esofágicas cervicais em dois planos de sutura com as feitas em um plano único extramucoso. Utilizou-se 60 cães, sadios, sem raça definida, de ambos os sexos, com peso médio de 15 kg. Foram separados em dois grupos iguais: no GRUPO I será [...] feita a anastomose em dois planos de sutura e, no GRUPO II, a em um plano único extramucoso. Cada grupo foi subdividido em 3 subgrupos iguais, e para cada um deles foi estabelecido um determinado período de observação pós-operatório (PO) de 7, 14 e 30 dias, respectivamente. As suturas foram feitas sempre com fio de polipropileno 4 zeros. Avaliou-se a incidência de complicações pós-operatórias imediatas e tardias e às características histológicas da cicatrização de cada tipo de anastomose. A análise estatística dos dados coletados permitiu verificar que na anastomose esôfago-esofágica cervical executada em um plano único extramucoso a porcentagem de fistulas (13,6%), e de estenoses (30%) ao nível da zona de sutura foi significantemente menor do que a observada na sutura realizada em dois planos de sutura em que as porcentagens foram de (26,7%) e (63,4%), respectivamente. A cicatrização das estruturas da parede esofágica ao nível da anastomose também foi significantemente melhor na anastomose em plano único extramucoso do que na em dois planos de sutura. Os resultados observados permitiram concluir que a anastomose em plano único extramucoso é mais eficaz do que a executada em dois planos de sutura. Abstract in english The objective of our study was to compare the efficacy of two types of cervical esophagus-esophageal anastomoses: two planes of suture versus a single extramucosal suture. Sixty healthy mongrel dogs of both sexes with a medium body weight of 15 kg. Were separated into two groups. Group one: anastomo [...] sis using two planes of suture; and Group two: anastomosis using one plane of extramucosal suture. Each group was divided into three subgroups based on post-operative time periods: 7, 14 and 30 days. Polypropylene 4-0 sutures were used in all anastomoses. The incidence of early and late post-operative complications and histological characteristics of the healing process at the site of the anastomoses were evaluated. Statistical analyses of the data collected permitted verification that the cervical esophagus-esophageal anastomoses done by only the extramucosal suture showed an incidence of 13.6% fistula and 30% stenosis at the level of the suture zone, which was significantly lower as compared to that observed in the two plane suture repair group where the percentages were 26.7 and 63.4 respectively. The healing of the structure of the esophageal wall at the level of the anastomosis was also significantly improved in the single plane extramucosal anastomosis group as compared to the two plane suture group. The observed results permitted conclusion that the extramucosal anastomosis in a single plane is more effícacious than that executed in two suture planes.

  7. Evaluation of high-strength orthopedic sutures: a head-to-head comparison.

    Science.gov (United States)

    Miller, Timothy; Feinblatt, Jeff; Craw, John; Litsky, Alan; Flanigan, David

    2010-09-01

    The goal of this study was to determine whether a difference in cycles to failure or mode of failure would be observed among specimens of 3 high-strength suture materials, and whether different suture configurations would affect knot security. Ten representative specimens of Ethibond (Ethicon, Inc, Somerville, New Jersey), FiberWire (Arthrex, Inc, Naples, Florida), MaxBraid (Biomet, Inc, Warsaw, Indiana), and Orthocord (DePuy Orthopaedics, Warsaw, Indiana) were tied in 6 different knot configurations commonly used in orthopedic procedures. Each specimen was cyclically loaded between 9 and 180 N at a rate of 1 Hz until the specimen failed or reached a maximum of 3500 cycles. Each suture material was subjected to tensile loading until failure at a rate of 1.25 mm/s. The 3 most secure knots all included the 3 reverse half-hitch on alternating posts (3-RHAP) configuration. All specimens tied with these 3 knot types failed by suture rupture. All knots using the overhand with 3 of the same half-hitches on the same post (O-3SHSP) configuration failed by knot slippage regardless of suture material. When the 3 strongest knots were combined, FiberWire resisted a significantly greater number of fatigue cycles than Orthocord or MaxBraid. In the single load to failure tests, Orthocord, FiberWire, and MaxBraid all had significantly higher ultimate strength than Ethibond. Knots using the 3-RHAP configuration provide security superior to that of those without this configuration. All 3 high-strength sutures tested outperformed Ethibond in single load to failure testing, with FiberWire resisting the greatest number of cycles. Postoperative strength and reliability of a soft tissue repair is inherently dependent on the properties of the suture materials used. PMID:20839707

  8. Influence of suturing material on wound healing: Experimental study in dogs

    Directory of Open Access Journals (Sweden)

    Gazivoda Dragan

    2015-01-01

    Full Text Available Background/Aim. The most common materials implanted in the human organism are suture materials that are classified on the basis of several criteria, usually the origin, structure, and properties. The properties of suture materials are related to its absorbability and non-absorbability. When using resorbable materials it is of great importance to determine whether its absorbability and tensile strength help wound healing in function of time. Sutures themselves can become a source of inflammation, that may reduce or compromise the potential of reparation and regeneration. The aim of this experimental study on dogs was to ascertain whether the absorption rate and the degree of local tissue reactions differ from information provided by the manufacturers, whether there are differences between the applied suture materials and which of the used suture materials have better effect on wound healing. Methods. Experimental testing of the selected suture materials basic characteristics was performed on 6 German Shepherd dogs, which, after induction of general anesthesia, were made 3 identical incisions each in all 4 quadrants (left and right side of the upper and lower jaws, so that 12 horizontal incisions were formed, 10 mm long, 20-25 mm distant from one another, on each animal. Randomly, incisions were stitched up in the following order, starting from back to front: catgut, Dexon®, Vicryl-Rapid®. The experiment was terminated by histopathological examination of tissue samples, taken on postoperative day 3, 7, 14 and 21 in order to identify the effect of healing and the degree of local reaction. Results. The obtained results suggest that catgut has the highest absorption rate, while Dexon® the lowest. Vicryl-Rapid® causes the lowest level of local reactions, while Dexon® the highest. Conclusion. There is no ideal suture material because various patient factors also influence the wound healing process.

  9. Changes to the cell, tissue and architecture levels in cranial suture synostosis reveal a problem of timing in bone development

    Directory of Open Access Journals (Sweden)

    J Regelsberger

    2012-11-01

    Full Text Available Premature fusion of cranial sutures is a common problem with an incidence of 3-5 per 10,000 live births. Despite progress in understanding molecular/genetic factors affecting suture function, the complex process of premature fusion is still poorly understood. In the present study, corresponding excised segments of nine patent and nine prematurely fused sagittal sutures from infants (age range 3-7 months with a special emphasis on their hierarchical structural configuration were compared. Cell, tissue and architecture characteristics were analysed by transmitted and polarised light microscopy, 2D-histomorphometry, backscattered electron microscopy and energy-dispersive-x-ray analyses. Apart from wider sutural gaps, patent sutures showed histologically increased new bone formation compared to reduced new bone formation and osseous edges with a more mature structure in the fused portions of the sutures. This pattern was accompanied by a lower osteocyte lacunar density and a higher number of evenly mineralised osteons, reflecting pronounced lamellar bone characteristics along the prematurely fused sutures. In contrast, increases in osteocyte lacunar number and size accompanied by mineralisation heterogeneity and randomly oriented collagen fibres predominantly signified woven bone characteristics in patent, still growing suture segments. The already established woven-to-lamellar bone transition provides evidence of advanced bone development in synostotic sutures. Since structural and compositional features of prematurely fused sutures did not show signs of pathological/defective ossification processes, this supports the theory of a normal ossification process in suture synostosis – just locally commencing too early. These histomorphological findings may provide the basis for a better understanding of the pathomechanism of craniosynostosis, and for future strategies to predict suture fusion and to determine surgical intervention.

  10. Aqueous Processes for Dyeing Generic, Unmodified Polypropylene Fiber

    Directory of Open Access Journals (Sweden)

    Murari L. Gupta

    2010-06-01

    Full Text Available Acid leuco vat dyeings of polypropylene (PP fabrics in combinations of a trichromatic series of colorants (red, yellow and blue plus an orange were performed in order to determine the compatibility of the component colorants in the developed single stage, batch exhaust dyeing process reported earlier. Cross-section micrographs of dyed fibers revealed the absence of "ring-dyeing". Tensile tests and X-ray crystallinity results confirmed that the developed dyeing process did not significantly alter the tensile strength and modulus of the dyed PP textiles. PP fabrics dyed with simulated, continuous acid vat dyeing processes (pad-steam and pad-dry heat demonstrated good color yields and levelness with adequate fastness to crocking, washing and dry cleaning.

  11. Effects of the Biodegradation on Biodegradable Polymer Blends and Polypropylene

    Science.gov (United States)

    Pereira, R. C. T.; Franchetti, S. M. M.; Agnelli, J. A. M.; Mattoso, L. H. C.

    2008-08-01

    The large use of plastics in the world generates a large amount of waste which persists around 200 years in the environment. To minimize this effect is important to search some new polymer materials: the blends of biodegradable polymers with synthetic polymers. It is a large area that needs an intensive research to investigate the blends properties and its behavior face to the different treatments to aim at the biodegradation. The blends used in this work are: some biodegradable polymers such as: poly(hydroxybutyrate) (PHB) and poly(?-polycaprolactone) (PCL) with a synthetic polymer, polypropylene (PP), in lower concentration. These blends were prepared using an internal mixer (Torque Rheometer), and pressed. These films were submitted to fungus biotreatment. The films analyses will be carried out by Fourier Transform Infrared (FTIR), UV-Vis absorption (UV-Vis), Scanning Electronic Microscopy (SEM), DSC and TGA.

  12. Identification of pressure-sensitive adhesive polypropylene tape.

    Science.gov (United States)

    Sakayanagi, Masataka; Konda, Yaeko; Watanabe, Kunio; Harigaya, Yoshihiro

    2003-01-01

    Identification of colorless, transparent, pressure-sensitive adhesive polypropylene tape (PP tape) was performed using infrared absorption spectrometry (IR) and pyrolysis gas chromatography mass spectrometry (Py-GC/MS) to determine the pressure-sensitive adhesive. Twenty different products of colorless, transparent PP tapes were examined in this study, and the results of analysis of IR spectra and Py-GC/MS were classified into twelve groups. In addition, the tapes were classified into 14 groups on the basis of IR measurement of release agent present in the backside. The results indicate that colorless, transparent PP tapes can be distinguished in terms of manufacturer, thereby demonstrating that this method of identifying colorless, transparent PP tape is effective. Moreover, the method was applied to the analysis of an actual forensic sample. PMID:12570201

  13. Characterization of Fibers Produced from Blends of Polybutylene and Polypropylene

    Directory of Open Access Journals (Sweden)

    Robert L. Shambaugh, Ph.D

    2007-11-01

    Full Text Available Blends of polybutylene (PB-1 and polypropylene were used to produce fibers at spinning speeds of 800-2100 m/min. Concentrations ranged from 0% PP to 100% PP. The stress-strain behavior of the resultant fibers was examined, and the fibers were analyzed for crystallinity via DSC (differential scanning calorimetry. Fibers produced from blends of PB-1/PP show mechanical properties that are in between the properties of the pure polymers. The tensile strength of 50% PB-1 fibers is comparable to the tensile strength of pure PP fibers. Fibers produced from blend compositions of 25 and 75% have higher tensile strengths than pure PP fibers, although these blend compositions have lower tensile strengths than pure PB fibers.

  14. Biocomposites from co-polypropylene and distillers' grains

    Science.gov (United States)

    Zarrinbakhsh, Nima; Mohanty, Amar K.; Misra, Manjusri

    2015-05-01

    In the present work, we have explored the polymeric composites of distillers' grains with co-polypropylene (co-PP). The effect of maleated-PP compatibilizer on mechanical, thermomechanical and physical properties was evaluated. The composite materials were produced by melt extrusion in a micro-compounder followed by injection molding in a micro-injection machine. The composites were characterized for their tensile, flexural and impact properties. Also, melt flow index and heat deflection temperature were measured. The results showed more than 30 % improvement in modulus when comparing the compatibilized biocomposite with neat co-PP. Also, the strength of the compatibilized biocomposite measured in tensile and flexural tests was comparable to or even better than that of the neat matrix. On the other hand, the reduced flexibility and toughness as a result of compatibilization were in an acceptable range. The biocomposites showed more rigidity at elevated temperatures. The produced distillers' grain biocomposites showed promises for industrial applications.

  15. [Treatment of postoperative abdominal hernias with polypropylene endoprosthesis].

    Science.gov (United States)

    Chakhvadze, B Iu; Nakashidze, D Kh

    2009-06-01

    The results of the surgical treatment of 82 patients with postoperative abdominal hernias were analysed. All of the patients underwent surgery with polypropylene endoprosthesis. The choice of a hernioplasty method depended on relative volume of postoperative hernia. Middle-sized hernias were indications for reconstructive surgery (complete adaptation of muscular and aponeurotic layers was maintained). The large and gigantic hernias were indications for correcting surgery (specified diastasis of muscular and aponeurotic layers was maintained). In case of lacking of peritoneum (30 patients) greater omentum was used for isolation of the net from intestinal loops. It is concluded that greater omentum provides good extraperitonisation of transplant from intestinal loop and prevents complications due to contact of net with abdominal organs. Postoperative complications mainly were local and seen in 29% cases. There were no lethal outcomes. PMID:19578204

  16. Raman Spectra and Mechanical Properties of Graphene/Polypropylene Nanocomposites

    Directory of Open Access Journals (Sweden)

    Siti R. Ahmad

    2015-02-01

    Full Text Available Graphene/Polypropylene nanocomposites were prepared at different filler loading and different average surface diameter 5, 15 and 25?m of graphene nanoplatelets by using Haake Minilab mixer at 180oC and rotor speed 50rpm. Besides, Haake MiniJet is used to obtain dumbbell shape specimen. The effect of filler loading and average surface area of filler in PP/GnP composites on Raman spectrum and tensile properties were studied. Raman spectrum of graphene particles indicate three major spectrums such as D, G and 2D band. In addition, PP/GnP composites shows the Raman band shift quite strong by increasing GnP loading. In general, increased of graphene nanoplatelets loading have increased the value of modulus of elasticity, whereas tensile strength, elongation at break of composites reduced

  17. Use of Cellulose-Containing Fillers in Composites with Polypropylene

    Directory of Open Access Journals (Sweden)

    Marina TAVROGINSKAYA

    2011-07-01

    Full Text Available The composites, containing recycled polypropylene and fillers, obtained from different lignocellulosics by the thermocatalytic destruction method, were investigated. Birch sawdust, newsprint wastes, cotton residues and wood bleached sulphate pulp were used as raw materials for obtaining fillers. The indices of mechanical properties (tensile strength, modulus of elasticity, deformation at break, shear modulus, toughness, twisting moment of the composites' samples were determined. It has been found that the obtained composites have relatively good mechanical properties. Better results were obtained, using fillers from sawdust and wood pulp. After treating the fillers with rapeseed oil, their water vapour sorption and water retention value (WRV decreased. In this case, the strength of the composites was higher.http://dx.doi.org/10.5755/j01.ms.17.2.484

  18. Conifer fibers as reinforcing materials for polypropylene-based composites

    DEFF Research Database (Denmark)

    Plackett, David; Chengzhi, Chuai

    2001-01-01

    Conifer fibers were used to reinforce polypropylene (PP). To improve the compatibility between the conifer fibers and the PP matrix, the fibers were either grafted with maleated PP (MAPP), treated by adding MAPP, or mixed with ethylene/propylene/diene terpolymer (EPDM). The treatments resulted in improved processing, as well as improvements in the thermal and mechanical properties of the resultant composites compared with the composites filled with untreated conifer fibers. Moreover, MAPP grafting and MAPP treating displayed more obvious benefits than EPDM treating in terms of thermal properties, processing flowability, and tensile strength improvements. EPDM treating also produced more significant benefits than either MAPP grafting or MAPP treating in terms of impact strength and tensile elongation improvements. These improvements were attributed to surface coating of the fibers when EPDM was used. In addition, the effect of the concentration of the conifer fibers on the properties of the composites and the difference between MAPP grafting and MAPP treating were evaluated.

  19. Polypropylene grafted with glycidyl methacrylate using supercritical CO2 medium

    Scientific Electronic Library Online (English)

    M. H., Kunita; E. M., Girotto; E. C., Muniz; A. F., Rubira.

    2006-06-01

    Full Text Available Films of polypropylene (PP) were grafted with glycidil methacrylate (GMA) using supercritical CO2 as swelling agent and solvent. Different pressures and temperatures were used to study their effects on the soaking and grafting process. FTIR results showed signals at 1726 and 1640 cm-1, assigned to C [...] =O and C=C (after the soaking process), and a decreased signal at 1640 cm-1 (after the grafting procedure), suggesting the effective grafting of GMA. For the grafted material immersed in ethylenediamine, peaks in the 3600 to 3250 cm-1 range (N-H stretching) were evident. Contact angle measurements showed an increasingly hydrophilic nature in the direction from pure PP to grafted PP/GMA (PP-g-GMA) to PP-g-GMA immersed in ethylenediamine (PP-g-GMA/En). X-ray photoelectron spectroscopy provided evidenced of the effective incorporation of ethylenediamine in the grafted material.

  20. Packing parameters effect on injection molding of polypropylene nanostructured surfaces

    DEFF Research Database (Denmark)

    Calaon, Matteo; Tosello, Guido

    2012-01-01

    In today´s industry, applications involving surface patterning of sub-?m to nanometer scale structures have shown a high growth potential. To investigate the injection molding capability of replicating sub-?m surface texture on a large scale area, a 30x80 mm2 tool insert with surface structures having a diameter of 500 nm was employed. The tool insert surface was produced using chemical-based-batch techniques such aluminum anodization and nickel electroplating. During the injection molding process, polypropylene (PP) was employed as material and packing phase parameters (packing time, packing pressure) were investigated. The replicated surface topographies were quantitatively characterized by atomic force microscopy using specific three-dimensional surface parameters and qualitatively inspected by scanning electron microscopy. Results showed that the degree of replication from the tool to the polymer part was mainly influenced by packing pressure level and distance from the gate.

  1. Reinforcing effect of nanosilica on polypropylene-nylon fibre composite

    International Nuclear Information System (INIS)

    Polymer composites reinforced by both the micro and nano fillers is the subject of this paper. Polypropylene (PP)-nylon micro-fibre composites modified with nanosilica and modified nanosilica (using silane coupling agent) were prepared by melt compounding. The nanosilica prepared in the laboratory was used as reinforcing filler in PP-nylon fibre composites. The compounding characteristics and mechanical properties of the composites were studied. The equilibrium torque during compounding increased with the addition of nanosilica and modified nanosilica. The use of two types of fillers leads to synergistic effect on the mechanical properties of the composite. Composites with 1 wt.% nanosilica and 30 wt.% nylon fibre show high tensile strength, tensile modulus, flexural strength and flexural modulus. Composites modified with 1 wt.% nanosilica and 10 wt.% nylon fibre-PP composite show higher impact strength.

  2. Surface treated polypropylene (PP) fibres for reinforced concrete

    Energy Technology Data Exchange (ETDEWEB)

    López-Buendía, Angel M., E-mail: buendia@uv.es [AIDICO Technological Institute of Construction, Benjamin Franklin 17, 46380 Paterna, Valencia (Spain); Romero-Sánchez, María Dolores [AIDICO Technological Institute of Construction, Marble Technical Unit, Camí de Castella 4, 03660 Novelda. Alicante (Spain); Climent, Verónica [Lafarge Cementos, Polígono Sepes, Isaac Newton s/n, 46500 Sagunto, Valencia (Spain); Guillem, Celia [AIDICO Technological Institute of Construction, Marble Technical Unit, Camí de Castella 4, 03660 Novelda. Alicante (Spain)

    2013-12-15

    Surface treatments on a polypropylene (PP) fibre have contributed to the improvement of fibre/concrete adhesion in fibre-reinforced concrete. The treatments to the PP fibre were characterized by contact angle measurements, ATR-IR and XPS to analyse chemical alterations. The surface topography and fibre/concrete interaction were analysed by several microscopic techniques, namely optical petrographic, and scanning electron microscopy. Treatment modified the surface chemistry and topography of the fibre by introducing sodium moieties and created additional fibre surface roughness. Modifications in the fibre surface led to an increase in the adhesion properties between the treated fibres and concrete and an improvement in the mechanical properties of the fibre-reinforced concrete composite as compared to the concrete containing untreated PP fibres. Compatibility with the concrete and increased roughness and mineral surface was also improved by nucleated portlandite and ettringite mineral association anchored on the alkaline PP fibre surface, which is induced during treatment.

  3. Electrical properties of foamed polypropylene/carbon black composites

    Science.gov (United States)

    Iliev, M.; Kotzev, G.; Vulchev, V.

    2016-02-01

    Polypropylene composites containing carbon black fillers were produced by vibration assisted extrusion process. Solid (unfoamed) composite samples were molded by conventional injection molding method, while structural foams were molded by a low pressure process. The foamed samples were evidenced to have a solid skin-foamed core structure which main parameters were found to depend on the quantity of material injected in the mold. The average bubbles' sizes and their distribution were investigated by scanning electron microscopy. It is established that the conductivity of the foamed samples gradually decreases when reducing the sample density. Nevertheless, the conductivity is found to be lower than the conductivity of the unfoamed samples both being of the same order. The flexural properties of the composites were studied and the results were discussed in the context of the structure parameters of the foamed samples.

  4. Processing-property relationships of polypropylene/ciprofloxacin fibers

    Science.gov (United States)

    Botta, L.; Scaffaro, R.

    2015-12-01

    In this work we prepared polypropylene (PP) fibers incorporating an antibiotic, i.e. ciprofloxacin (CFX), by melt spinning. In particular, PP has been compounded with CFX at different concentrations by using a counter-rotating twin screw compounder. The PP/CFX fibers have been spun by using a capillary rheometer operating under a constant extrusion speed. The effect of "online" hot drawing during the melt spinning or of an "offline" cold drawing on the properties of PP/CFX fibers were evaluated. In particular, the influence of the drawing conditions on the mechanical properties and the release kinetics were studied. Moreover, the rheological behavior in non-isothermal elongation flow has been assessed.

  5. Preparation of polypropylene thermoplastic container via thermoforming process

    Science.gov (United States)

    Ruqiyah Nik Hassan, Nik; Amira Mohd Ghazali, Farah; Aziz Jaafar, Abdul; Mazni Ismail, Noor

    2016-02-01

    In this study, plastic containers made of polypropylene (PP) sheets were fabricated via vacuum thermoforming. Thermoforming is a process used in fabricating plastic parts by changing flat thermoplastic sheet to three dimensional shapes. In preparing these thermoplastic containers, the design and fabrication of mould were first done by using Catia V5 software and CNC milling machine, respectively. The thermoforming process was then performed at various temperatures ranging from 160°C until 200°C on the PP sheet to form the container. From the experiment, it can be suggested that the outcomes of final thermoplastic containers are significantly depends on temperature control during thermoforming process and also the vent holes design of the mould.

  6. Thermal degradation and viscoelasticity of polypropylene-clay nanocomposites

    CERN Document Server

    Drozdov, A D; Drozdov, D A; Gupta, R K

    2003-01-01

    Results of torsional oscillation tests are reported that were performed at the temperature T=230C on melts of a hybrid nanocomposite consisting of isotactic polypropylene reinforced with 5 wt.% of montmorillonite clay. Prior to mechanical testing, specimens were annealed at temperatures ranging from 250 to 310C for various amounts of time (from 15 to 420 min). Thermal treatment induced degradation of the matrix and a pronounced decrease in its molecular weight. An integro-differential equation is derived for the evolution of molecular weight based on the fragmentation-aggregation concept. This relation involves two adjustable parameters that are found by fitting observations. With reference to the theory of transient networks, constitutive equations are developed for the viscoelastic response of nanocomposite melts. The stress-strain relations are characterized by three material constants (the shear modulus, the average energy for rearrangement of strands and the standard deviation of activation energies) tha...

  7. Simulating the Oxidation of Polypropylene Using a Reactive Forcefield

    Science.gov (United States)

    Budzien, Joanne; Thompson, Aidan

    2007-03-01

    Oxidation of organic materials is a problem for seals and membranes in many environments. Any particular instance of a chemical reaction is fast with purely local effects. Over longer times, the cumulative effect of many reactions results in large changes in average stress, strain, and other macroscopic properties of the sample. We have had some success in developing constitutive models for rubber, which connect the topology of the network with the observed stress during aging under strain. As the next phase of the project, we have performed simulations using a reactive forcefield to examine the atomistic changes during oxidation. Results will be presented for polypropylene and compared with experimental data for labeled samples undergoing oxidation.

  8. Space Charge and Electrical Conduction Properties of Polypropylene Copolymer Films

    Science.gov (United States)

    Nakane, Emi; Kaneko, Kazue; Mori, Tatsuo; Mizutani, Teruyoshi; Takino, Hiroshi; Ishioka, Mitsugu

    We investigated the space charge and charging current characteristics in polypropylene copolymer films polymerized with metallocene and Ziegler-Natta catalysts, respectively. Positive and negative homo space charges were observed and their amounts showed maxima at 40 °C. Charge carriers injected from the semiconducting (SC) electrode were dominant at 60 °C. The copolymerization of ethylene enhanced the apparent carrier mobility and the charging current. Evaporated Al electrode showed much less carrier injection than Al plate or SC electrode (mechanically-contacted electrode). Carrier injection from SC electrode was dominant than that from Al plate. These suggest that the space charge formation depends on not only electrode materials but also contact conditions.

  9. Can Suture Repair of ACL Transection Restore Normal Anteroposterior Laxity of the Knee? An Ex Vivo Study

    Science.gov (United States)

    Fleming, Braden C.; Carey, James L.; Spindler, Kurt P.; Murray, Martha M.

    2009-01-01

    INTRODUCTION Recent work has suggested the transected ACL can heal and support reasonable loads if repaired with sutures and a bioactive scaffold; however, use of a traditional suture configuration results in knees with increased AP laxity. The objective was to determine whether one of five different suture repair constructs when performed at two different joint positions would restore normal AP knee laxity. METHODS AP laxity of the porcine knee at 60° of flexion was evaluated for five suture repair techniques. Femoral fixation for all repair techniques utilized a suture anchor. Primary repair was to either the tibial stump, one of three bony locations in the ACL footprint, or a hybrid bony fixation. All five repairs were tied with the knee in first 30° and then 60° of flexion for a total of 10 repair constructs. RESULTS Suture repair to bony fixation points within the anterior half of the normal ACL footprint resulted in knee laxity values within 0.5 mm of the ACL-intact joint when the sutures were tied with the knee at 60° flexion. Suture repair to the tibial stump, or with the knee at 30° of flexion, did not restore normal AP laxity of the knee. CONCLUSIONS Three specific suture repair techniques for the transected porcine ACL restored the normal AP laxity of the knee at the time of surgery. Additional studies defining the changes in laxity with cyclic loading and in vivo healing are indicated. PMID:18528857

  10. Crystallization and melting of biodegradable poly(propylene suberate)

    International Nuclear Information System (INIS)

    Highlights: ? Thermal behavior of biodegradable polyester poly(propylene suberate) is discussed. ? Tmo and ?Hmo were found 79.7 oC and 28.9 kJ/mol, respectively. ? Banded spherulitic morphology was observed. ? Crystallization regime II to III transition appears at 40 oC. ? Interestingly Ozawa model for non-isothermal crystallization fits experimental data. - Abstract: Thermal behavior of poly(propylene suberate) (PPSub) was studied. PPSub is a novel biodegradable polyester which always shows lower crystallinity, and thus faster biodegradation, than poly(?-caprolactone) or poly(butylene succinate). Crystalline structure, multiple melting behavior and re-crystallization of PPSub on heating were studied by using Wide Angle X-ray Diffraction (WAXD), Differential Scanning Calorimetry (DSC) and Step Scan DSC. The equilibrium melting point and the enthalpy of fusion of the pure crystalline polymer were found 79.7 oC and 28.9 kJ/mol, respectively. Polarized Light Microscopy (PLM) tests showed that PPSub forms banded spherulites. The Lauritzen-Hoffman theory was used. Values of spherulite growth rates and also overall crystallization rates after self-nucleation, from DSC data, were used. In the latter case the inverse of crystallization half times or the Avrami constant K values were supposed to be a measure of crystallization rates. Critical breakpoint in the Lauritzen-Hoffman plots appeared at 40 oC showing crystallization regime II to III transition. Non-isothermal crystallization kinetics was also analyzed. Interestingly, the Ozawa model seems to hold for PPSub. The iso-conversional method of Friedman was used to study the activation energy of PPSub crystallization on cooling and the Lauritzen-Hoffman parameters were also calculated by applying the Vyazovkin method.

  11. Evaluation of the Stability of Polypropylene toward Gamma Radiation

    International Nuclear Information System (INIS)

    Polypropylene (PP) is one of the polymers commonly employed in industry in fabrication of medical devices. However, PP tends to degrade when sterilized through gamma radiation at a dose of 25 kGy in an atmosphere containing oxygen, becoming a brittle material that could fail during its application. Therefore, the purpose of the present study was to analyze the use of different additives such as antioxidants (phenols and sterically hindered amines, BHT and Chimassorb 944, respectively), by adding them individually or as a blend into PP in order to increase its resistance to degradative effects caused by gamma radiation. Additives content varied from 0.1 to 0.8 wt.%. The effect of the radiation atmosphere (air, nitrogen) onto the polymer properties was also analyzed. The presence of carbonyl groups, decrease of the average molecular weight, abrupt increase of Melt Flow Index (MFI) and material elasticity loss with radiation clearly showed that polypropylene without any additive suffered degradation by a chain scission mechanism. Instead, addition of antioxidants, either individually or the blend of them, showed a stabilizing effect by retarding the carbonyl groups appearance, slowing down the molecular weight decrease and, in some cases, elasticity and thermal properties were maintained. Moreover, in some specific compositions, the use of a nitrogen atmosphere during the radiation process maintained MFI as well as molecular weight values under control. Finally, it can be concluded that the process of deterioration of the PP properties when exposed to gamma radiation can be retarded by the adequate use of commercial additives, and even more effectively if an inert atmosphere is employed when sterilization is performed

  12. Nuevo método de sutura subcutánea percutánea continua / New method of continuous percutaneous subcutaneous suture

    Scientific Electronic Library Online (English)

    Germán, Brito Sosa; Reinaldo, Echevarría Romero.

    2012-06-01

    Full Text Available Objetivos: realizar un método de sutura continua, en las personas operadas en el Hospital "Julio Trigo López", que disminuya los granulomas a nivel de la herida quirúrgica, y compararlas con el método tradicional. Métodos: se realizó un estudio experimental sobre la aplicación de un método de sutura [...] subcutánea percutánea continua, en un grupo de pacientes operados de diversas enfermedades, ya sea de urgencia, electivo o ambulatorio, en el Hospital "Julio Trigo López", en los años 2008 y 2009. Resultados: con el método de sutura subcutánea percutánea continua con nylon no se forman granulomas, mientras que con el método tradicional, sí ocurre en un porcentaje no despreciable. Las ventajas del método de sutura subcutánea percutánea continua con nylon son: en el plano celular subcutáneo de la pared abdominal no queda sutura, no se producen granulomas y es más económica. Conclusiones: la sutura de nylon es menos rechazada que la del cromado, ya que no se producen granulomas. El método de sutura subcutánea percutánea continua es una sutura más hemostática que el método tradicional, ya que el por ciento de hematomas es menor. El gasto económico es menor con el método de sutura subcutánea percutánea continua. Con el método de sutura subcutánea percutánea continua la sutura es extraída al 10mo. día de haberla aplicado. Abstract in english Objectives: to apply a continuous suture method to reduce granulomas in surgical wounds in patients operated on at "Julio Trigo Lopez" hospital, and to compare the results with those of the traditional method. Methods: an experimental study was conducted on the application of a continuous percutaneo [...] us subcutaneous suture in a group of patients operated on from several diseases, either under emergency, elective or outpatient conditions at "Julio Trigo Lopez" hospital during 2008 and 2009. Results: the continuous percutaneous subcutaneous suture method with nylon prevents formation of granulomas, whereas the traditional method did show a percentage of granulomas that is not small at all. The advantages of the former are the following: there is no suture left at subcutaneous cellular level of the abdominal wall, granulomas are absent and it is a more economic option. Conclusions: the nylon suture is less rejected than the chromated suture since granulomas do not appear. The continuous percutaneous subcutaneous suture method offers a more hemostatic suture than the traditional method, being the number of hematomas lower. The economic cost is reduced and the suture may be taken out ten days after surgery.

  13. A simple technique for performing laparoscopic purse-string suturing during circular stapling anastomosis.

    Science.gov (United States)

    Takiguchi, Shuji; Sekimoto, Mitsugu; Fujiwara, Yoshiyuki; Miyata, Hiroshi; Yasuda, Takushi; Doki, Yuichiro; Yano, Masahiko; Monden, Morito

    2005-01-01

    An esophagojejunostomy using a circular stapler requires the fixing of an anvil at the esophageal stump. When this placement procedure is laparoscopically performed, purse-string suturing is difficult, and there is a risk of loosening when a conventional needle driver is used. We herein present a simple but effective technique for performing laparoscopic purse-string suturing of the esophageal stump using a semiautomatic suturing device called the Endostitch. Gastrointestinal anvil placement was laparoscopically performed for 10 patients who underwent an esophagojejunostomy following a total gastrectomy. After the lumen of the esophagus was expanded using bowel forceps, the Endostitch was used to place approximately 12 encircling purse-string sutures. An anvil was positioned with support of the esophageal wall at three points with forceps. The Endostitch was used for the ligation with a sufficient degree of tension applied by extracorporeally pulling the sutures through the abdominal wall. The time for placement of the anvil averaged approximately 8 min. The ring formation following anastomosis was favorable in all patients. As a result, we consider our technique to be simple but very effective. PMID:16175476

  14. Bioactive and mechanically strong Bioglass-poly(D,L-lactic acid) composite coatings on surgical sutures.

    Science.gov (United States)

    Chen, Q Z; Blaker, J J; Boccaccini, A R

    2006-02-01

    New coating processes have been investigated for degradable (Vicryl) and nondegradable (Mersilk) sutures with the aim to develop Bioglass coated polymer fibers for wound healing and tissue engineering scaffold applications. First, the aqueous phase of a Bioglass particle slurry was replaced with a poly(D,L-lactic acid) (PDLLA) polymer dissolved in solvent dimethyle carbonate (DMC) to act as third phase. SEM observations indicated that this alteration significantly improved the homogeneity of the coatings. Second, a new coating strategy involving two steps was developed: the sutures were first coated with a Bioglass-PDLLA composite film followed by a second PDLLA coating. This two-step process of coating has addressed the problem of poor adherence of Bioglass particles on suture surfaces. The coated sutures were knotted to determine qualitatively the mechanical integrity of the coatings. The results indicated that adhesion strength of coatings obtained by the two-step method was remarkably enhanced. A comparative assessment of the bioactivity of one-step and two-step produced coatings was carried out in vitro using acellular simulated body fluid (SBF) for up to 28 days. Coatings produced by the two-step process were found to have similar bioactivity as the one-step produced coatings. The novel Bioglass/PDLLA/Vicryl and Bioglass/PDLLA/Mersilk composite sutures are promising bioactive materials for wound healing and tissue engineering applications. PMID:16161126

  15. Post operation recurrence of inguinal hernia in children and its relation with suture material

    Directory of Open Access Journals (Sweden)

    Omid Amanollahi

    2011-09-01

    Full Text Available Background: Using non-absorbable suture in children hernia repair to decrease of recurrence is recommended in the most pediatric surgery centers. The aim of this study was to determine relationship between kind of suture material and rate of hernia recurrence. Methods: In this clinical trial 200 children (age 1-5 years with inguinal hernia who operated in Imam-Reza Hospital (kermanshah –Iran Between April 2007 until April 2008 enrolled into the study. Cases were selected by convenience sampling method and then randomly divided into two groups (100 cases per group and operated with absorbable (silk 3-0 and non-absorbable (vicryli 3-0 suture material. Following period was 12 months after operation and collected data analyzed by statistical software. Emergency operations were excluded from the study.Results: 83% of patients were boy and 17% were girl. %53 showed right side inguinal, 29% left side and %18 were bilateral hernia. After one year follow up only one case of recurrence was observed in each group.Conclusion: Our study confirmed that recurrence of inguinal hernia in children after surgery, is not related to kind of suture material (absorbability and we didn’t find any significant difference. Other factors than suture material may influence recurrence rate of hernia operation in children.

  16. LED phototherapy on midpalatal suture after rapid maxilla expansion: a Raman spectroscopic study

    Science.gov (United States)

    Rosa, Cristiane B.; Habib, Fernando Antonio L.; de Araújo, Telma M.; dos Santos, Jean N.; Cangussu, Maria Cristina T.; Barbosa, Artur Felipe S.; de Castro, Isabele Cardoso V.; Soares, Luiz Guilherme P.; Pinheiro, Antonio L. B.

    2015-03-01

    A quick bone formation after maxillary expansion would reduce treatment timeand the biomodulating effects of LED light could contribute for it. The aim of this study was to analyze the effect of LED phototherapy on the acceleration of bone formation at the midpalatal suture after maxilla expansion. Thirty rats divided into 6 groups were used on the study at 2 time points - 7 days: Control; Expansion; and Expansion + LED; and 14 days: Expansion; Expansion + LED in the first week; Expansion and LED in the first and second weeks. LED irradiation occurred at every 48 h during 2 weeks. Expansion was accomplished using a spatula and maintained with a triple helicoid of 0.020" stainless steel orthodontic wire. A LED light (?850 ± 10nm, 150mW ± 10mW, spot of 0.5cm2, t=120 sec, SAEF of 18J/cm2) was applied in one point in the midpalatal suture immediately behind the upper incisors. Near infrared Raman spectroscopic analysis of the suture region was carried and data submitted to statistical analyzes (p?0.05). Raman spectrum analysis demonstrated that irradiation increased hydroxyapatite in the midpalatal suture after expansion. The results of this indicate that LED irradiation; have a positive biomodulation contributing to the acceleration of bone formation in the midpalatal suture after expansion procedure.

  17. Visibility of sutures of the orbit and periorbital region using multidetector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Gufler, Hubert; Preis, Markus; Koesling, Sabrina [Dept. of Diagnostic Radiology, Martin-Luther-University Halle-Wittenberg, Halle (Germany)

    2014-12-15

    Knowledge of cranial suture morphology is crucial in emergency medicine, forensic medicine, and maxillofacial reconstructive surgery. This study assessed the visibility of sutures of the orbit and periorbital region on multidetector computed tomography. Multidetector computed tomography scans of 200 patients (127 males, 73 females; mean age 51.3 years; range, 6-92 years) were evaluated retrospectively. The slice thicknesses varied from 0.5 to 1 mm, and the tube current from 25 to 370 mAs, depending on the CT indication. The visibility of sutures was estimated according to a 4-point scale from 'not visible to well visible' The chi-squared test was used to test the association of the visibility of sutures with the slice thickness, tube current, and age of patients. Statistical significance was assumed at p < 0.05. Overall, best visibility was found for the sutura frontozygomatica (98%), sutura frontonasalis (88.5%), and sutura sphenozygomatica (71.5%), followed by the sutura zygomaticomaxillaris (65.8%), sutura temporozygomatica (41.8%), sutura frontomaxillaris (44.5%), and sutura sphenofrontalis (31%). Poor visibility was found for the sutura frontolacrimalis (16.8%) and sutura frontoethmoidalis (1.3%). The sutura ethmoidomaxillaris, sutura lacrimomaxillaris, and sutura ethmoidolacrimalis were not visible. Although the sutures of the superior, lateral, and inferior orbit are well visible, those of the medial orbit are poorly visible on CT scans.

  18. Physical and dielectric properties of irradiated polypropylene and poly(ethylene terephthalate)

    International Nuclear Information System (INIS)

    The effect of high-energy electron irradiation in air and in nitrogen on the physical and dielectric properties of polypropylene and poly(ethylene terephthalate) has been studied by measurements of electric strength, dielectric constant, dissipation factor, tensile strength, gel fraction and molecular weight distribution. Electric strength of polypropylene was improved by irradiation, while dielectric properties of poly(ethylene terephthalate) were virtually unaffected by irradiation of 1.0-20 Mrad. Possible mechanisms for increasing electric strength are discussed from the point of view of degradation and oxidation taking place simultaneously with crosslinking of polypropylene. The maximum dose level to improve the electric strength of polypropylene is determined to be about 5 Mrad. (author)

  19. Effect of processing conditions on the mechanical and thermal properties of high-impact polypropylene nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Furlan, L.G. [Federal Institute of Rio Grande do Sul, IFRS, Campus Restinga, Estrada Joao Antonio da Silveira, 351, Porto Alegre 91790-400 (Brazil); Ferreira, C.I.; Dal Castel, C.; Santos, K.S.; Mello, A.C.E. [Chemistry Institute, Federal University of Rio Grande do Sul, UFRGS, Av. Bento Goncalves, 9500, Porto Alegre 91501-970 (Brazil); Liberman, S.A.; Oviedo, M.A.S. [Braskem S.A., III Polo Petroquimico, Via Oeste, Lote 5, Triunfo 95853-000 (Brazil); Mauler, R.S., E-mail: mauler@iq.ufrgs.br [Chemistry Institute, Federal University of Rio Grande do Sul, UFRGS, Av. Bento Goncalves, 9500, Porto Alegre 91501-970 (Brazil)

    2011-08-25

    Highlights: {yields} Polypropylene montmorillonite (PP-MMT) produced at different processing conditions. {yields} Polypropylene Nanocomposites with higher increase on impact resistance. {yields} Higher enhancement on mechanical properties. - Abstract: Polypropylene montmorillonite (PP-MMT) nanocomposites have been prepared by using a co-rotating twin screw extruder. The effects of processing conditions at fixed clay content (5 wt%) on polymer properties were investigated by means of transmission electron microscopy (TEM), flexural modulus, izod impact, dynamic mechanical analysis (DMA), and differential scanning calorimetry (DSC). It was noticed that the morphology and the mechanical properties of polypropylene nanocomposites were affected by different screw shear configuration. The results showed that the higher enhancement on mechanical properties was obtained by medium shear intensity profile instead of high configuration. An exceptional increase (maximum of 282%) on impact resistance was observed.

  20. Trapping of polycyclic aromatic hydrocarbons by amphiphilic cyclodextrin functionalized polypropylene nonwovens

    DEFF Research Database (Denmark)

    Lumholdt, Ludmilla; Nielsen, Ronnie Bo Højstrup; Larsen, Kim Lambertsen

    textile fibers. In this study we present the ability of amphiphilic CD coated polypropylene nonwovens to trap 8 different polycyclic aromatic hydrocarbons/endocrine disruptors from aqueous solutions thus demonstrating the potential of using the amphiphilic cyclodextrins for water purification....

  1. Long-term stability of irradiated polypropylene fibers and carboxylic cationites on their base

    International Nuclear Information System (INIS)

    Study is carried out of polypropylene fibers and fibrous carboxylic cationites on their base, which have been obtained by radiation graft polymerization of acrylic acid by the method of preliminary irradiation of polypropylene fibers on air (gamma-rays of 60Co, dose rate 0.37 Gy/s, dose 5-140 kGy). Mechanical and sorptive properties of polypropylene fibers and cationites are investigated after long-term storage in different conditions. The cationite obtained has excellent sorption properties towards cations of Cd, Pb, Cu. Zn, Fe and etc. It is shown that conditions of graft polymerization and storage influence on long-term stability of carboxylic cationites on the base of polypropylene fibers. It is pointed out that the use of cross-linking agent considerably increases long-term stability of grafted fibers

  2. Effect of processing conditions on the mechanical and thermal properties of high-impact polypropylene nanocomposites

    International Nuclear Information System (INIS)

    Highlights: → Polypropylene montmorillonite (PP-MMT) produced at different processing conditions. → Polypropylene Nanocomposites with higher increase on impact resistance. → Higher enhancement on mechanical properties. - Abstract: Polypropylene montmorillonite (PP-MMT) nanocomposites have been prepared by using a co-rotating twin screw extruder. The effects of processing conditions at fixed clay content (5 wt%) on polymer properties were investigated by means of transmission electron microscopy (TEM), flexural modulus, izod impact, dynamic mechanical analysis (DMA), and differential scanning calorimetry (DSC). It was noticed that the morphology and the mechanical properties of polypropylene nanocomposites were affected by different screw shear configuration. The results showed that the higher enhancement on mechanical properties was obtained by medium shear intensity profile instead of high configuration. An exceptional increase (maximum of 282%) on impact resistance was observed.

  3. Fluid handling and fabric handle profiles of hydroentangled greige cotton and spunbond polypropylene nonwoven topsheets

    Science.gov (United States)

    Absorbent nonwoven topsheets are traditionally spunbond (or spunbond-meltblown (SM)) polypropylene nonwoven fabrics, and are used for a wide range of incontinence applications. Here we describe how nonwoven greige cotton demonstrates positive incontinence performance indices suitable for top sheet ...

  4. Analysis of Flexural Strength for Steel, Glass and Polypropylene Fiber Reinforced Concrete

    OpenAIRE

    Chapala. Venkata x Venkata Ramana; CH. Naga Sindhura

    2012-01-01

    This analysis study is done by using different types of fibres such as steel, glass and polypropylene with aspect ratio varying from 20 to 120 for steel, 600 to 860 for glass and 30 to 100 for polypropylene fibres.The total fibre percentages of 0 to 2�0for steel, 0 to 2�0for glass and 0 to 2.5�0for polypropylene with variation of 0.25�he design mix varying from M20 to M60 with water cement ratio 0.3 to 0.55 for steel, 0.16 to 0.55 for glass and 0.46 for polypropylene.After being cured under t...

  5. Study on the method of identification of irradiated polypropylene by ESR spectroscopy

    International Nuclear Information System (INIS)

    Electron spin resonance (ESR) signals were detected from irradiated polypropylene, which is widely used as packing material of food products. Optimum conditions were investigated for identifying irradiated food indirectly using ESR spectroscopy. From the ESR spectra, the g1, g2 and g3 factors for irradiated polypropylene were 2.0350±0.0002, 2.0089±0.0002 and 2.0052±0.0002, respectively. ESR intensity of irradiated polypropylene was positively correlated with microwave power, modulation amplitude and absorbed dose, and the detection limit was 0.5 kGy within 30 days post irradiation. The study provides a basis for identifying irradiated food products packed by polypropylene. (authors)

  6. hermal Stability of Clay's Galleries in Polypropylene - Clay (montmorillonite Nanocomposites using Polypropylene-g-Maleic Anhydride as Compatibilizer

    Directory of Open Access Journals (Sweden)

    Pandu Lanang Kinasih

    2009-04-01

    Full Text Available Superior properties of food packaging can be achieved using nanocomposite technology. However, fabrication of this materials are complex and expensive. Long term objectives of this research is the synthesis of low cost polypropylene clay nanocomposites (PPCN via a short-cut method known as ‘cascade engineering'. Cascade engineering principle in PPCN fabrication is performed by using compatibilizer (to enable the mixing of PP and clay masterbatch, and PPCN in one pot process using melt mixer. This paper present the experimental results using small-angle x-ray diffraction (XRD on the thermal stability of the PPCN. Results from the XRD analysis showed that the clay was intercalated, however no significant changes were observed as a result of variation in mixing time. XRD patterns of the annealed PPCN showed reduction of MMT's gallery (deintercalation These phenomenon was probably caused by insufficient bonding and lack of compatibility between PP-g-MA and MMT.

  7. INVESTIGATION OF THE MORPHOLOGICAL AND THERMAL PROPERTIES OF WASTE NEWSPRINT/ RECYCLED POLYPROPYLENE/ NANOCLAY COMPOSITE

    OpenAIRE

    Mohammad Amin Danesh,; Hassan Ziaei Tabari,; Reza Hosseinpourpia; , Noradin Nazarnezhad,; Morteza Shams

    2012-01-01

    The main objective of this research was to study the potential of waste polypropylene and waste newsprint fiber for making wood-plastic nanocomposites. We used 30 wt.% waste newsprint fiber and 10 wt.% compatilizer in this study. Nanoclay was used at two levels: 2.5 and 5% by wt. Materials were mixed with either recycled or virgin polypropylene. The effects of nanoclay (NC) on the mechanical and thermal properties were also studied. The improvements in tensile properties of the blended compos...

  8. Functionalization of PP for the enhancement of adhesion between polypropylene and polyamide multilayers

    OpenAIRE

    Rustal, Claude

    2009-01-01

    The aim of the present work was the production of a polypropylene/polyamide three-layer film without using any tie-layers. These films could find an application, for instance, in the packaging or medical industries. To promote adhesion between the two immiscible polymers, two strategies were used: addition of compatibilizers in the polypropylene (PP) matrix and direct functionalization of the PP matrix with reactive monomers such as maleic anhydride and glycidyl methacrylate. In the first...

  9. Electron beam irradiations of polypropylene syringe barrels and the resulting physical and chemical property changes

    International Nuclear Information System (INIS)

    Mechanical, thermal, chemical decomposition and electron spin resonance (ESR) methods were used to study electron beam irradiated polypropylene syringe barrels that were irradiated to a total fractionated dose of 0, 20, 40, 60, and 80 kGy (in steps of 20 kGy). Dose mapping was conducted to determine dose to and through the syringe barrel. Analysis of these data indicated that degradation of the polypropylene syringes increased with an increase in electron beam irradiation.

  10. Effect of Polypropylene Fiber on Shrinkage Properties of Cement-stabilized Macadam

    OpenAIRE

    Zhifeng Chen

    2009-01-01

    A parametric experimental study has been conducted to investigate the effect of polypropylene fiber on the shrinkage of cement-stabilized macadam. By means of the micrometer gauge method and the strain gauge method, the dry shrinkage coefficient and thermal shrinkage coefficient of cement-stabilized macadam were measured respectively. The results indicate that polypropylene fiber can effectively decrease the average dry shrinkage coefficient and average thermal shrinkage coefficient of cement...

  11. Development of a Halogen Free Flame Retardant Masterbatch for Polypropylene Fibers

    Directory of Open Access Journals (Sweden)

    François Rault

    2015-02-01

    Full Text Available The efficiency of new phosphinates, in combination with melamine cyanurate, was studied using different polypropylene textile structures. The influence of different ratios up to a total amount of 6 wt% in the polypropylene fiber was investigated using the limiting oxygen index (LOI and cone calorimeter method for research purposes, while the performances were correlated to the standards FMVSS 302 (Federal Motor Vehicle Safety Standards and DIN 4102-l (Deutsches Institut für Normung used more specifically for automotive and building sector.

  12. Characterization of calcium carbonate obtained from oyster and mussel shells and incorporation in polypropylene

    OpenAIRE

    Michele Regina Rosa Hamester; Palova Santos Balzer; Daniela Becker

    2012-01-01

    There is a high content of calcium carbonate in mussel and oyster shells, which can be used in the formulation of medicine, in construction or as filler in polymer materials. This work has as its main objective to obtain calcium carbonate from mussel and oyster shells and used as filler in polypropylene compared their properties with polypropylene and commercial calcium carbonate composites. The shellfish was milling and heated at 500 ºC for 2 hours. The powder obtained from shellfish were ch...

  13. Antimicrobial polymers from polypropylene/silver composites—Ag+ release measured by anode stripping voltammetry

    OpenAIRE

    Radheshkumar, C.; Münstedt, H.

    2006-01-01

    Polypropylene/silver composites were subjected to silver ion release experiments in order to investigate their Ag+ release capabilities, a pertinent condition for antimicrobial efficacy. Polypropylene containing elementary silver powder having a specific surface area of 0.78 m2/g was considered as the principal antimicrobial filler. In addition the effectiveness of other commercial antimicrobials based on silver were also examined. Evidence is presented for the release of silver ions...

  14. Development of a Halogen Free Flame Retardant Masterbatch for Polypropylene Fibers

    OpenAIRE

    François Rault; Stéphane Giraud; Fabien Salaün; Xavier Almeras

    2015-01-01

    The efficiency of new phosphinates, in combination with melamine cyanurate, was studied using different polypropylene textile structures. The influence of different ratios up to a total amount of 6 wt% in the polypropylene fiber was investigated using the limiting oxygen index (LOI) and cone calorimeter method for research purposes, while the performances were correlated to the standards FMVSS 302 (Federal Motor Vehicle Safety Standards) and DIN 4102-l (Deutsches Institut für Normung) used mo...

  15. Enhancing the Dyeability of Polypropylene Fibers by Melt Blending with Polyethylene Terephthalate

    OpenAIRE

    Fereshteh Mirjalili; Siamak Moradian; Farhad Ameri

    2013-01-01

    Attempts were made to modify polypropylene fibers by melt blending with polyethylene terephthalate in order to enhance the dyeability of the resultant fiber. Five blends of polypropylene/polyethylene terephthalate/compatibilizer were prepared and subsequently spun into fibers. Three disperse dyes were used to dye such modified fibers at boiling and 130°C. The dyeing performance of the blend fibers, as well as the morphological, chemical, thermal, and mechanical properties, of the correspondin...

  16. Tensile strength characteristics of polypropylene composites reinforced with stone groundwood fibers from softwood

    OpenAIRE

    Joan P. López,; José A. Méndez,; Francesc X. Espinach,; Fernando Julián,; Pere Mutjé; Fabiola Vilaseca

    2012-01-01

    The behavior of stone groundwood / polypropylene injection-molded composites was evaluated with and without coupling agent. Stone groundwood (SGW) is a fibrous material commonly prepared in a high yield process and mainly used for papermaking applications. In this work, the use of SGW fibers was explored as a reinforcing element of polypropylene (PP) composites. The surface charge density of the composite components was evaluated, as well as the fiber’s length and diameter inside the composit...

  17. Application to refrigerator plastics by mechanical recycling from polypropylene in waste-appliances

    International Nuclear Information System (INIS)

    Highlights: → Polypropylene is mechanically recycled from waste-appliances. → Recycled polypropylene (RPP) is impact enhanced polypropylene with ethylene-propylene rubber (EPR). → Performance evaluation shows that RPP is applicable to refrigerator plastics. -- Abstract: For the application to refrigerator plastics by mechanical recycling from polypropylene (PP) in waste-appliances, it needs to identify the degradation and heterogeneity of recycled polypropylene (RPP). It is applicable the thermal analysis such as differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), spectroscopic analysis such as Fourier Transform Infrared (FTIR) and morphological analysis such as scanning electronic microscope (SEM). The analysis results show that RPP from waste-appliances is the polyethylene (PE) and polypropylene (PP) copolymer enhanced impact property (Impact-PP) and it is possible to apply refrigerator plastics with good impact property at low temperature. Finally, the performance evaluation of RPP is estimated by Gel Permeation Chromatography (GPC) analysis and is performed by the various mechanical and physical testing methods. It shows that RPP has relatively high molecular weight and balanced properties with strength and toughness. It is expected that RPP by the mechanical recycling from waste-appliances will have about 50% cost-merit.

  18. Effect of compatibilization and reprocessing on the isothermal crystallization kinetics of polypropylene/wood flour composites

    Directory of Open Access Journals (Sweden)

    Arieny Rodrigues

    2013-01-01

    Full Text Available Numerous studies have focused on polymer mixtures aimed at the potential applications of these materials. This work analyzed the effect of polymer reprocessing and the type and concentration of compatibilizer on the isothermal crystallization kinetics of polypropylene/wood flour composites. The composites, which were polypropylene grafted with acrylic acid (PP-g-AA and maleic anhydride (PP-g-MA, were processed in a twin screw extruder with and without compatibilizer. Reprocessed polypropylene reached complete crystallization in less time than the composites with virgin polypropylene. The addition of wood flour to the composites did not change the kinetics significantly compared to that of the pure polymers, but the compatibilizers did, particularly PP-g-AA. The nucleation exponent (n and crystallization rate (K were calculated from Avrami plots. The values of n ranged from 2 to 3, indicating instantaneous to sporadic nucleation. The crystallization half-time of reprocessed polypropylene was shorter than that of virgin polypropylene and of the compositions containing PP-g-AA compatibilizer. The activation energy of crystallization and the equilibrium melting temperature were calculated, respectively, from Arrhenius and Hoffman-Weeks plots. Both of these parameters showed lower values in the composites, particularly in the ones containing compatibilizers.

  19. Effect of compatibilization and reprocessing on the isothermal crystallization kinetics of polypropylene/wood flour composites

    Scientific Electronic Library Online (English)

    Arieny, Rodrigues; Benjamim de M., Carvalho; Luís A., Pinheiro; Rosário E. S., Bretãs; Sebastião V., Canevarolo; Juliano, Marini.

    Full Text Available Numerous studies have focused on polymer mixtures aimed at the potential applications of these materials. This work analyzed the effect of polymer reprocessing and the type and concentration of compatibilizer on the isothermal crystallization kinetics of polypropylene/wood flour composites. The comp [...] osites, which were polypropylene grafted with acrylic acid (PP-g-AA) and maleic anhydride (PP-g-MA), were processed in a twin screw extruder with and without compatibilizer. Reprocessed polypropylene reached complete crystallization in less time than the composites with virgin polypropylene. The addition of wood flour to the composites did not change the kinetics significantly compared to that of the pure polymers, but the compatibilizers did, particularly PP-g-AA. The nucleation exponent (n) and crystallization rate (K) were calculated from Avrami plots. The values of n ranged from 2 to 3, indicating instantaneous to sporadic nucleation. The crystallization half-time of reprocessed polypropylene was shorter than that of virgin polypropylene and of the compositions containing PP-g-AA compatibilizer. The activation energy of crystallization and the equilibrium melting temperature were calculated, respectively, from Arrhenius and Hoffman-Weeks plots. Both of these parameters showed lower values in the composites, particularly in the ones containing compatibilizers.

  20. Radiation modification and interaction mechanism of polypropylene and polyethylene by protons and electrons

    International Nuclear Information System (INIS)

    A systematic investigation of radiation effects on isotactic polypropylene (PP) and low-density polyethylene (PE) films by protons and electrons is reported. Electrons can make polyethylene cross-linked and polypropylene crached while protons can improve the PP mechanical properties and deteriorate polyethylene with increasing the irradiation dose. The structural analysis shows that conversion between ? and ? phases occurs and the crystallinity remains constant in the electron-irradiated polypropylene whereas the network structure is formed by allyl-type radicals in the e--irradiated polyethylene. The infrared spectra indicate that conformational changes have taken place in the polypropylene under proton bombardment, such as the transition from an ordered to a disordered state in the crystalline region, the formation of double bonds as well as trans-conformations. This leads to the cross-linking between macromolecules of polypropylene at the proper irradiation doses, thus enhancing its mechanical properties. The cross-linking of polypropylene by proton bombardment observed and its properties may have some potential applications

  1. Analysis of Flexural Strength for Steel, Glass and Polypropylene Fiber Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Chapala. Venkata x Venkata Ramana

    2012-12-01

    Full Text Available This analysis study is done by using different types of fibres such as steel, glass and polypropylene with aspect ratio varying from 20 to 120 for steel, 600 to 860 for glass and 30 to 100 for polypropylene fibres.The total fibre percentages of 0 to 2�0for steel, 0 to 2�0for glass and 0 to 2.5�0for polypropylene with variation of 0.25�he design mix varying from M20 to M60 with water cement ratio 0.3 to 0.55 for steel, 0.16 to 0.55 for glass and 0.46 for polypropylene.After being cured under the standard conditions for age of 28 days the specimens of each mixture were tested to determine the corresponding flexural strength. The parameters such as grade of concrete, aspect ratio, volume fraction and tensile strength of fibre for steel, glass and polypropylene fibres respectively, while the flexural strength of the concrete were chosen as output variable. The results obtained from the model and the experiments were compared by using regression analysis, and it was check in artificial neural networks. Finally form an empirical relation between flexural strength tograde of concrete, aspect ratio, volume fraction and tensile strength of fibre for steel, glass and polypropylene fibres.

  2. Thermal and mechanical properties of polypropylene/titanium dioxide nanocomposite fibers

    International Nuclear Information System (INIS)

    Highlights: â–º Wet synthesis method was used for the synthesis of TiO2 nano particles. â–º Mechanical properties of polypropylene fibers were increased by the addition of TiO2 nanoparticles. â–º Thermal stability of polypropylene fiber was improved significantly by the addition of TiO2 nano particles. â–º TiO2 nanoparticles dispersed well in polypropylene fibers. -- Abstract: Titanium dioxide nanoparticles were prepared by wet synthesis method and characterized by transmission electron microscopy and X-ray diffraction studies. The nanotitanium dioxide then used to prepare polypropylene/titanium dioxide composites by melt mixing method. It was then made into fibers by melt spinning and subsequent drawing. Mechanical properties of the fibers were studied using Favimat tensile testing machine with a load cell of 1200 cN capacity. Thermal behavior of the fibers was studied using differential scanning calorimetry and thermogravimetric analysis. Scanning electron microscope studies were used to investigate the titanium dioxide surface morphology and crosssection of the fiber. Mechanical properties of the polypropylene fiber was improved by the addition of titanium dioxide nanoparticles. Incorporation of nanoparticles improves the thermal stability of polypropylene. Differential scanning calorimetric studies revealed an improvement in crystallinity was observed by the addition of titanium dioxide nanoparticles.

  3. Photo-oxidative degradation of TiO2/polypropylene films

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Photo-oxidative degradation of polypropylene is accelerated by TiO2 incorporation. • Weight loss, FTIR, SEM and GPC shown high degree of degradation of polypropylene. • A mechanism of the photo-degradation of polypropylene by TiO2 is proposed. - Abstract: Photo-oxidative degradation of polypropylene films with TiO2 nanoparticles incorporated was studied in a chamber of weathering with Xenon lamps as irradiation source. TiO2 powder with crystalline structure of anatase was synthesized by thermal treatments at 400 and 500 °C starting from a precursor material obtained by sol–gel method. Composites of TiO2/polypropylene were prepared with 0.1, 0.5 and 1.0 wt% of TiO2. The mixture of components was performed using a twin screw extruder, the resulting material was pelletized by mechanical fragmenting and then hot-pressed in order to form polypropylene films with TiO2 dispersed homogeneously. Photo-oxidative degradation process was followed by visual inspection, weight loss of films, scanning electron microscopy (SEM), infrared spectroscopy with Fourier transformed (FTIR), and gel permeation chromatography (GPC)

  4. Performance Assessment of Suture Type in Juvenile Chinook Salmon Surgically Implanted with Acoustic Transmitters

    Energy Technology Data Exchange (ETDEWEB)

    Deters, Katherine A.; Brown, Richard S.; Carter, Kathleen M.; Boyd, James W.

    2009-02-27

    The objective of this study was to determine the best overall suture material to close incisions from the surgical implantation of Juvenile Salmon Acoustic Telemetry System (JSATS) acoustic microtransmitters in subyearling Chinook salmon Oncorhynchus tshawytscha. The effects of seven suture materials, four surgeons, and two water temperatures on suture retention, incision openness, tag retention, tissue inflammation, and tissue ulceration were quantified. The laboratory study, conducted by researchers at the Pacific Northwest National Laboratory, supports a larger effort under way for the U.S. Army Corps of Engineers, Portland District, aimed at determining the suitability of acoustic telemetry for estimating short- and longer-term (30-60 days) juvenile-salmonid survival at Columbia and Snake River dams and through the lower Columbia River.

  5. Deep electromagnetic (MT and AMT) sounding of the suture zones of the Ukrainian shield

    Science.gov (United States)

    Antsiferov, A. V.; Sheremet, E. M.; Nikolaev, Yu. I.; Nikolaev, I. Yu.; Setaya, L. D.; Antsiferov, V. A.; Omelchenko, Al. A.

    2011-01-01

    The article discusses the results of deep magnetotelluric sounding of suture zones in the Precambrian structures of the Ukrainian shield in the context of collisional settings. All the considered suture zones (Orekhovo-Pavlograd, West Ingulets-Krivoi Rog, Golovanevsk-Yadlov-Traktemir, Nemirov-Kocherov or Brusilov) are associated with the regional anomalies of increased electric conductivity, which mark deep fault zones and characterize collisional settings. The nature of such deep anomalies might be due to the transport of the ore components together with the fluids from the crust and the mantle during the tectonomagmatic activation, which offers the possibility to predict the prospective areas of endogenic mineralization. A correlation has been established between the endogenic ore deposits located close to or within the suture zones and the low-resistivity anomalies.

  6. NON ABSORBABLE INTERMITTENT MATTRESS SUTURES IN THE MANAGEMENT OF AURICULAR HAEMATOMA

    Directory of Open Access Journals (Sweden)

    Muralidhar Reddy

    2014-12-01

    Full Text Available Auricular haematoma of pinna usually occurs secondary to trauma. If left untreated usually result in a deformity known as cauliflower ear. Various treatments are employed so as to produce the best cosmetic results. The aim of this article was to evaluate the outcome and complications of the treatment of auricular haematoma using non-absorbable 3-0 prolene intermittent sutures. This study has been performed upon eight patients presented with auricular haematoma at tertiary center, Govt. ENT Hospital, Koti, Hyderabad between August 2013 to August 2014. Follow up was continued for 6 months. The commonest cause behind auricular haematoma was personal insult. It was found that incision and drainage followed by suturing with non-absorbable intermittent mattress sutures appear to be simple, well tolerated and excellent method in treatment and preventing re-accumulation of auricular haematoma and to avoid ear deformity (Cauliflower ear.

  7. Arthroscopic 4-Point Suture Fixation of Anterior Cruciate Ligament Tibial Avulsion Fractures

    Science.gov (United States)

    Boutsiadis, Achilleas; Karataglis, Dimitrios; Agathangelidis, Filon; Ditsios, Konstantinos; Papadopoulos, Pericles

    2014-01-01

    Tibial eminence avulsion fractures are rare injuries occurring mainly in adolescents and young adults. When necessary, regardless of patient age, anatomic reduction and stable internal fixation are mandatory for fracture healing and accurate restoration of normal knee biomechanics. Various arthroscopically assisted fixation methods with sutures, anchors, wires, or screws have been described but can be technically demanding, thus elongating operative times. The purpose of this article is to present a technical variation of arthroscopic suture fixation of anterior cruciate ligament avulsion fractures. Using thoracic drain needles over 2.4-mm anterior cruciate ligament tibial guidewires, we recommend the safe and easy creation of four 2.9-mm tibial tunnels at different angles and at specific points. This technique uses thoracic drain needles as suture passage cannulas and offers 4-point fixation stability, avoiding potential complications of bony bridge fracture and tunnel connection. PMID:25685674

  8. Light-guided localization within tissue using biocompatible surgical suture fiber as an optical waveguide

    Science.gov (United States)

    Choi, Woo June; Park, Kwan Seob; Lee, Byeong Ha

    2014-09-01

    In breast-conserving surgery, an optical wire is a useful surgical guiding tool to optically locate small lesions within the breast tissue. However, the use of a long silica glass fiber as the optical wire can be burdensome to patients because of its stiffness and nonbiocompatibility. We investigate the use of a biocompatible fiber for light localization in tissue. A surgical suture with a diameter of 400 ?m and a few centimeters long is employed as the biocompatible optical waveguide to transport the visible laser light to the inner tissue site. Optical location is confirmed with glow ball-like red laser illumination at the tip of the suture embedded within a fresh chicken breast tissue. Effective optical power coupling to the suture is made by using a double-cladding fiber coupler. From this preliminary result, we realize practical light localization with biopolymer waveguides.

  9. Application of Self-retaining Bidirectional Barbed Absorbable Suture in Retroperito- neoscopic Partial Nephrectomy

    Scientific Electronic Library Online (English)

    Wang, Ke; Zhang, Yu-Lian; Lin, Chun-Hua; Liu, Dong-Fu; Men, Chang-Ping; Wang, Jian-Ming; Gao, Zhen-Li.

    2014-04-01

    Full Text Available ObjectiveTo investigate the safety and feasibility of self-retaining bidirectional barbed absorbable suture application in retroperitoneoscopic partial nephrectomy.Materials and MethodsFrom Sep 2011 and Aug 2012, 76 cases of retroperitoneoscopic partial nephrectomy were performed at our hospital. Th [...] e patients were divided into two groups: self-retaining barbed suture (SRBS) group (n = 36) and non-SRBS group (n = 40). There was no significant difference in age, sex, tumor size and location between the two groups. Clinical data and outcomes were analyzed retrospectively.ResultsAll 76 cases of retroperitoneoscopic partial nephrectomy were successfully performed, without conversion to open surgery or serious intraoperative complications. In the SRBS group, the suture time, warm ischemia time and operation blood loss were significantly shorter than that of non-SRBS group (p

  10. Precision of suture placement with microscope- and loupe-assisted anastomoses.

    Science.gov (United States)

    Rooks, M D; Slappey, J; Zusmanis, K

    1993-01-01

    Twenty-eight anastomoses involving seven surgeons were done on 2 mm Gortex vascular prostheses to test the effect of magnification on the precision of suture placement. One-half were done with 3.5-4x prism loupe magnification and the other one-half with 8-30x microscope magnification. The variability of suture placement (defined here as precision) was measured in a blinded fashion. The mean suture puncture to prosthesis edge measurement for the microscope-assisted group was approximately 0.03 mm closer to the edge. The variability from the mean for the microscope-assisted group was approximately 0.01 mm less than that for the loupe-assisted group. This difference was statistically significant at a P value of 0.0123. PMID:8271935

  11. Emergency treatment of a ruptured huge omphalocele by simple suture of its membrane

    Directory of Open Access Journals (Sweden)

    Akakpo-Numado Gamedzi

    2012-02-01

    Full Text Available Abstract Background The rupture of a huge omphalocele is an emergency that threatens the newborn baby's life. It constitutes a therapeutical concern in the absence of prosthesis especially in developing countries. Methods We are reporting herein the case of a newborn baby that we managed in emergency successfully thanks to a simple treatment. Results It was a huge omphalocele, ruptured during delivery, in a male newborn baby. We conducted a simple and conservative surgical treatment without prosthesis, which consisted of reconstruction of the omphalocele's membrane by closing it with absorbable suture materials. The suture of the omphalocele's membrane was followed by treatment with the Grob's method. This treatment saved the newborn baby's life. The total skinning was obtained after 3 months. Conclusions In case of rupture of huge omphalocele in absence of prosthesis, it is better to suture the membrane, and continue the treatment according to the Grob's method; the residual disembowelment can be repaired later.

  12. Flexor tendon repair: a comparative study between a knotless barbed suture repair and a traditional four-strand monofilament suture repair.

    LENUS (Irish Health Repository)

    Joyce, C W

    2014-01-01

    We compared the tensile strength of a novel knotless barbed suture method with a traditional four-strand Adelaide technique for flexor tendon repairs. Forty fresh porcine flexor tendons were transected and randomly assigned to one of the repair groups before repair. Biomechanical testing demonstrated that the tensile strengths between both tendon groups were very similar. However, less force was required to create a 2 mm gap in the four-strand repair method compared with the knotless barbed technique. There was a significant reduction in the cross-sectional area in the barbed suture group after repair compared with the Adelaide group. This would create better gliding within the pulley system in vivo and could decrease gapping and tendon rupture.

  13. The role of biological adhesive and suture material on rabbit hepatic injury

    OpenAIRE

    Taha Murched Omar; De Rosa Karen; Fagundes Djalma José

    2006-01-01

    PURPOSE: To evaluate the performance of fibrin adhesive and absorbable suture thread in the repairing of hepatic injures in rabbits. METHODS: New Zealand albino rabbits (n=16), males and females, from 5 to 6 months old, average weight of 2500 g, were distributed randomly in Group A (n-8) - biological adhesive and Group B (n=8) - suture thread. After anesthesia with acepromazine (1mg/Kg), ketamine (50mg/Kg) and fentanyl EV (0,5ml/Kg), it was performed a supra-umbilical median laparotomy, the m...

  14. Image-based tracking of the suturing needle during laparoscopic interventions

    Science.gov (United States)

    Speidel, S.; Kroehnert, A.; Bodenstedt, S.; Kenngott, H.; Müller-Stich, B.; Dillmann, R.

    2015-03-01

    One of the most complex and difficult tasks for surgeons during minimally invasive interventions is suturing. A prerequisite to assist the suturing process is the tracking of the needle. The endoscopic images provide a rich source of information which can be used for needle tracking. In this paper, we present an image-based method for markerless needle tracking. The method uses a color-based and geometry-based segmentation to detect the needle. Once an initial needle detection is obtained, a region of interest enclosing the extracted needle contour is passed on to a reduced segmentation. It is evaluated with in vivo images from da Vinci interventions.

  15. Leyla loop: a time-saving suture technique for robotic atrial closure

    OpenAIRE

    K?l?ç, Leyla; ?enay, ?ahin; A. Ümit Güllü; Alhan, Cem

    2013-01-01

    The longer durations of cardiopulmonary bypass and aortic cross-clamp times remain the disadvantages of robotic or minimally invasive cardiac surgery. For this reason, every small contribution to speeding up these procedures is of the utmost importance. Here, we present a practical, easy and time-saving suture technique for atrial closure. It consists of a hand-made loop at one end of the suture and saves the time otherwise consumed by knotting. It may also be used during conventional or mini...

  16. Suture Granuloma Showing False-Positive Findings on FDG-PET

    OpenAIRE

    Kohei Takahara; Hiroaki Kakinoki; Saya Ikoma; Kazuma Udo; Shohei Tobu; Yuji Satoh(Institute of Physics, University of Tsukuba, Ibaraki 305-8571, Japan); Yuji Tokuda; Mitsuru Noguchi; Shigehisa Aoki; Jiro Uozumi

    2013-01-01

    We report a case of a 33-year-old male with a mixed germ-cell testicular tumor. Postoperative follow-up FDG-PET revealed concentration of FDG in the left inguinal area which is not tumor metastasis or local recurrence but suture reactivity granuloma. In this paper, we reviewed suture granulomas associated with false-positive findings on FDG-PET after surgery. If FDG-PET will be used more frequently in the future, it will be necessary to refrain from using silk thread in order to prevent any u...

  17. [Current status and perspectives of mechanical suture techniques in abdominal and thoracic surgery].

    Science.gov (United States)

    Kockel, N; Ulrich, B

    1991-01-01

    In surgery the application of mechanical suture techniques is increasing. In order to inform the surgeons in detail about the different surgical stapling instruments being available today, the mechanical suture devices are listed in this article. These instruments can be divided into linear staplers, circular and linear anastomosis staplers, ligating clips and skin and fascia staplers. Own experiences with stapling instruments, their advantages and disadvantages as well as the different forms of application are described. Further information is given on the increasing use of absorbable staples and of new anastomosis techniques, i.e. instruments creating an anastomosis on the principle of compression. PMID:2042415

  18. Randomised controlled study of two different techniques of skin suture in endoscopic release of carpal tunnel

    DEFF Research Database (Denmark)

    Hansen, Torben Bæk; Kirkeby, Lone

    2009-01-01

    In a prospective, randomised trial of 54 hands in 47 patients incisions were randomised to be closed by either absorbable subcuticular (polyglytone 6211, Caprosyn), or non-absorbable interrupted (polybutester, Novafil), sutures after single-portal endoscopic release of the carpal tunnel. There was a significant reduction in pain scores on days 1 and 2 in the patients treated with an absorbable continuous subcuticular suture, and no difference in inflammation or infection. There was no difference in the cosmetic appearance between the two groups after three months.

  19. Assessment of the shrinkage and ejection forces of reinforced polypropylene based on nanoclays and short glass fibre

    OpenAIRE

    Garcia, M. C. R.; Netto, A. C. S.; A. J. Pontes

    2013-01-01

    In this study the influence of nanoclay and glass fibre in the shrinkage and ejection forces in polypropylene matrix in tubular parts moulded by injection moulding were analysed. An instrumented mould was used to measure the part surface temperature and ejection forces in tubular parts. The materials used were a polypropylene homopolymer Domolen 1100L nanoclay for polyolefin nanocomposites P-802 Nanomax in percentages of 2%, 6% and 10% and a polypropylene homopolymer with conte...

  20. The Influence of Drawing on Molecular Mobility in Polypropylene Fibers

    International Nuclear Information System (INIS)

    The influence of drawing at a certain temperature on molecular mobility of polypropylene (PP) fibers has been studied by means of broad-line nuclear magnetic resonance (NMR). Both, drawing and temperature of drawing influence physical properties of PP fibers. NMR technique is shown to be advantageous for study of these changes on molecular level since the shape of broad-line NMR spectra and processes of the NMR relaxation depend on the spatial configuration and motion of the resonating nuclei. Our measurements were performed on the sets of polypropylene fibers made from isotactic PP marked as Tatren 430 produced in Slovakia. Fibers were drawn at the temperatures Td = 293 K and 373 K to draw ratio ? from 1 to 5.5. The NMR measurements were carried out on spectrometer RYa - 2301 in the temperature range 200 - 400 K at the resonance frequency f0 = 14.1 MHz. The samples were prepared from fibers densely wounded on a thin teflon rod in the form of small solenoid. The axis of solenoid was perpendicular to external magnetic field. NMR spectra have been analysed by means of modified Bergmann's method on assumption that each spectrum measured at a given temperature may be expressed as a sum of three elementary spectra y(x) = wnyn(x, Bm, ?L) + wmym(x, ?mL, ?mG) + wbyb(x, s) (1) in which x B - B0 is a difference between the applied magnetic field induction B and the resonance magnetic field B0, Bm is the amplitude of modulating magnetic field. The narrowest spectral component yn, corresponding to the chains with highest mobility, is the Lorentzian function influenced by modulation field. The middle component ym, corresponding to the chains with hindered mobility, is the product of the Lorentzian and Gaussian functions. The broad component yb, representing rigid (immobile) chains of crystalline and highly oriented non crystalline regions, is an experimental NMR spectrum measured at the lowest temperature - 200 K in our case. The weight factors wn, wm, wb determine the relative number of the macromolecular chains in the three above mentioned phases, differing in their structure and chain's mobility. The weight factors fulfil the condition wn + wm + wb = 1. Parameters ?L, ?mL, ?mG and s determine the widths of corresponding elementary spectra. The decomposition of the NMR spectrum has been realized by fitting the experimental spectra according to equation (1) by the least square method. The temperature dependences of the wi (i = n, m, b) indicate that drawing of PP fibers and temperature of drawing influence molecular mobility of PP chains in the temperature region corresponding to the ?-relaxation. (author)