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1

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

LENUS (Irish Health Repository)

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.

Davis, N F

2012-11-01

2

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)

3

Development of advanced antimicrobial and sterilized plasma polypropylene grafted muga (antheraea assama) silk as suture biomaterial.  

Science.gov (United States)

Surface modification of silk fibroin (SF) materials using environmentally friendly and non-hazardous process to tailor them for specific application as biomaterials has drawn a great deal of interest in the field of biomedical research. To further explore this area of research, in this report, polypropylene (PP) grafted muga (Antheraea assama) SF (PP-AASF) suture is developed using plasma treatment and plasma graft polymerization process. For this purpose, AASF is first sterilized in argon (Ar) plasma treatment followed by grafting PP onto its surface. AASF is a non-mulberry variety having superior qualities to mulberry SF and is still unexplored in the context of suture biomaterial. AASF, Ar plasma treated AASF (AASFAr ) and PP-AASF are subjected to various characterization techniques for better comparison and the results are attempted to correlate with their observed properties. Excellent mechanical strength, hydrophobicity, antibacterial behavior, and remarkable wound healing activity of PP-AASF over AASF and AASFAr make it a promising candidate for application as sterilized suture biomaterial. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 355-365, 2014. PMID:23913788

Gogoi, Dolly; Choudhury, Arup Jyoti; Chutia, Joyanti; Pal, Arup Ratan; Khan, Mojibur; Choudhury, Manash; Pathak, Pallabi; Das, Gouranga; Patil, Dinkar S

2014-04-01

4

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.

5

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  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Akinrinmade, J. F.; Lawal, A. O.

2010-01-01

6

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)

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.

Álvaro Gianlupi

2004-04-01

7

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 seg [...] mento 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. Abstract in english 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.

Álvaro, Gianlupi; Manoel Roberto Maciel, Trindade.

2004-04-01

8

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)

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.

Nelson Leonardo Kerdahi Leite de Campos

2003-10-01

9

Effect of suture material on postoperative astigmatism.  

Science.gov (United States)

Two hundred patients were enrolled in a randomized, prospective clinical trial comparing the use of 10-0 nylon, 10-0 polypropylene (Prolene), 11-0 polyester (Mersilene), and 10-0 polyethylene (Novafil) suture materials on the amount and decay curves of surgically induced astigmatism following intraocular lens (IOL) surgery. Patients with Mersilene and nylon sutures had the highest amounts of induced with-the-rule (WTR) cylinder (significantly more than Prolene) at one day after surgery. However, the WTR cylinder decayed rapidly for nylon during the first three months but more slowly for Mersilene because of its lack of stretchability. The Prolene group had the lowest level of induced WTR cylinder at one day, but against-the-rule (ATR) drift occurred, leaving cases with ATR astigmatism by a year. The nylon group had the second highest amount of induced WTR cylinder at one day, which had decayed to ATR cylinder by five months. Between one and two years postoperatively, the nylon group experienced a significant ATR shift. The amount of early induced WTR cylinder seemed to be related to the knot-tying technique and tissue gripping characteristics, whereas the shape of the decay curve was related to the material characteristics of the suture. PMID:1531234

Gimbel, H V; Raanan, M G; DeLuca, M

1992-01-01

10

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish 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 e [...] n 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. Abstract in english 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 sut [...] ure 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.

J. F, Akinrinmade; A. O, Lawal.

1221-12-01

11

Knotting technique and suture materials.  

Science.gov (United States)

Three groups of knots were examined using six no. 1 (metric 4) suture materials to identify the most effective and efficient knotting techniques. The three groups were the square or reef knot, the surgeon's knot and a double throw knot. Sequential single additional throws were added to these in order to determine when the strength of the knot reached the breaking force of the material, thus nullifying the need for additional throws. This strength was reached in all cases by a maximum of two additional throws. Suture materials examined were the non-absorbable monofilaments nylon and polypropylene, the absorbable monofilaments polyglyconate and polydioxanone and the braided materials polyglactin and polyglycolic acid, both coated. These were examined for their knot-holding capacity and breaking force to determine the best materials, which were polypropylene, polyglyconate and polyglycolic acid. PMID:1596717

Brown, R P

1992-05-01

12

Knot security of suture materials.  

Science.gov (United States)

The knot security of chromic gut, polyglycolic acid, polyglactin 910, polydioxanone, polypropylene, and monofilament nylon size 2-0 suture materials were tested biomechanically in vitro. Twenty reproducible knots were tied and incubated in canine serum at 37 degrees for 24 hours before testing. A "secure knot" was defined as a knot that, when tested to failure, broke rather than untied by slippage. The minimum number of throws necessary to make a secure, snug (1500 g tension) square knot was three for gut, polyglycolic acid, polyglactin 910, and polypropylene and four for polydioxanone and nylon. All throws including the first were counted. With all suture materials tested, surgeon's knots were as secure as square knots. Only gut, polyglycolic acid, and polydioxanone granny knots were as secure as square knots; no loosely tied (500 g tension) asymmetric square knots were as secure as snug square knots, and only polydioxanone and polypropylene loose square knots were as secure as snug square knots. Square knots used to start a continuous pattern required one additional throw with gut, polydioxanone, and nylon. Square knots used to end a continuous pattern required two to three additional throws with all materials tested. PMID:2505438

Rosin, E; Robinson, G M

1989-01-01

13

Effect of suture material on platelet deposition onto prosthetic material  

Energy Technology Data Exchange (ETDEWEB)

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. Indium 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.

Connolly, R.; McEnroe, C.S.; Li, S.; Coleman, J.; Callow, A.D.

1988-07-01

14

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 resccessive irradiation is effective to restrain material degradation. (author)

15

Suture materials in contaminated wounds: a detailed comparison of a new suture with those currently in use.  

Science.gov (United States)

The relationship between five different suture materials (expanded polytetrafluoroethylene (PTFE), polypropylene, polyglycolic acid, polydioxanone and polyglactin 910) and infection has been studied in 540 guinea-pig wounds contaminated with synergistic enteric organisms. The recently introduced expanded PTFE suture has been studied because, unlike the others, it has not previously been studied under these contaminated conditions. The incidence of wound infection in the control series was 26 per cent and all suture materials increased this figure significantly. The infection rate using expanded PTFE of 51 per cent was similar to all other sutures except polyglycolic acid, which produced an infection rate of 41 per cent. This difference was not statistically significant at the 5 per cent level. This confirms other studies including our own which show that the presence of most suture materials in contaminated wounds increases the incidence of infection. It further demonstrates that expanded PTFE is no different from other materials in this regard. PMID:2820538

Paterson-Brown, S; Cheslyn-Curtis, S; Biglin, J; Dye, J; Easmon, C S; Dudley, H A

1987-08-01

16

Quantitative evaluation of stiffness of commercial suture materials.  

Science.gov (United States)

The bending stiffness of 22 commercial suture materials of varying size, chemical structure and physical form was quantitatively evaluated using a stiffness tester (Taber V-5, model 150B, Teledyne). The commercial sutures were Chromic catgut; Dexon (polyglycolic acid); Vicryl (polyglactin 910); PDS (polydioxanone); Maxon (polyglycolide-trimethylene carbonate); Silk (coated with silicone); Mersilene (polyester fiber); Tycron (polyester fiber); Ethibond (polyethylene terephthalate coated with polybutylene); Nurolon (nylon 66); Surgilon (nylon 66 coated with silicone); Ethilon (coated nylon 66), Prolene (polypropylene); Dermalene (polyethylene), and Gore-tex (polytetraflouroethylene). These are both natural and synthetic, absorbable and nonabsorbable and monofilament and multifilament sutures. All of these sutures were size 2-0, but Prolene sutures with sizes ranging from 1-0 to 9-0 were also tested to determine the effect of suture size on stiffness. The bending stiffness data obtained showed that a wide range of bending stiffness was observed among the 22 commercial sutures. The most flexible 2-0 suture was Gore-tex, followed by Dexon, Silk, Surgilon, Vicryl (uncoated), Tycron, Nurolon, Mersilene, Ethibond, Maxon, PDS, Ethilon, Prolene, Chromic catgut, coated Vicryl, and lastly, Dermalene. The large porous volume inherent in Gore-tex monofilament suture was the reason for its lowest flexural stiffness. Sutures with a braided structure were generally more flexible than those of a monofilament structure, irrespective of the chemical constituents. Coated sutures had significantly higher stiffness than the corresponding uncoated ones. This is particularly true when polymers rather than wax were used as the coating material. This increase in stiffness is attributable to the loss of mobility under bending force in the fibers and yarns that make up the sutures. An increase in the size of the suture significantly increased the stiffness, and the magnitude of increase depended on the chemical constituent of the suture. The flexural stiffness of sutures was also found to depend on the duration of bending in the test for stiffness. In general, monofilament sutures exhibited the largest time-dependent stiffness. This was most pronounced with the Gore-tex suture. Most braided sutures also showed less time-dependence in stiffness. Nylon sutures did not exhibit this time-dependent phenomenon regardless of physical form. PMID:2919353

Chu, C C; Kizil, Z

1989-03-01

17

The pH dependence of monofilament sutures on hydrolytic degradation.  

Science.gov (United States)

Hydrolytic degradation of two nonabsorbable sutures, four absorbable sutures, and a new type of absorbable suture was studied in buffered media of various pHs at 37 degrees C. The pH levels fixed in this study were 1.0, 7.4, 8.5, and 10.5. Physical measurements were made on the retention of tensile strength and melting temperature of the sutures after hydrolysis for 12 weeks. Sutures containing glycolic acid as a comonomer exhibited enhanced degradation in alkaline media, similar to polyglycolide multifilament sutures. Poly-p-dioxanone (PDS II) suture lost strength to a significant extent at pH 1.0, suggesting that care should be taken when this suture is used for closing tissues in contact with acidic media, such as the stomach. In marked contrast, the degradation of lactide-epsilon-caprolactone copolymer [P(LA/CL)] suture was not sensitive to the pH of media. The surface morphology of hydrolyzed sutures varied, depending on the pH of media. Particularly, moon-crater-shaped impressions were observed on glycolide-epsilon-caprolactone copolymer (MONOCRYL) and glycolide-trimethylene carbonate-dioxanone copolymer (BIOSYN) sutures. Among the nonabsorbable sutures, nylon (ETHILON) exhibited the fastest loss of strength in acidic buffer solution, and polypropylene (PROLENE) suture retained most of its initial strength at all pHs studied. PMID:11505425

Tomihata, K; Suzuki, M; Ikada, Y

2001-01-01

18

The effect of suture material on platelet deposition onto prosthetic material.  

Science.gov (United States)

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. PMID:3196613

Connolly, R; McEnroe, C S; Li, S; Coleman, J; Callow, A D

1988-01-01

19

[The role of suture material on healing of vascular anastomosis].  

Science.gov (United States)

The effect of suture material on healing of vascular anastomosis was examined. Four types of vascular grafts, i.e., autogenous vein, preserved human umbilical cord vein, expanded polytetrafluoroethylene and double velour knitted Dacron, were implanted into the abdominal aorta of 78 adult mongrel dogs using two kinds of absorbable sutures (multifilament polyglycolic acid: PGA and monofilament polydioxanone: PDS) and a nonabsorbable suture (polypropylene: PP). The macroscopic findings and the histologic examinations showed that hyalinoid degeneration and calcification resulting from tissue ischemia due to tight and long lasting suture loops interfered with tissue healing at the PP-anastomotic site. On the other hand, fairly good healing of the anastomoses was observed with absorbable sutures because of the reduction of ischemia. The absorbable suture-anastomoses could tolerate systemic blood pressure within one month after implantation, and there was no anastomotic disruption at 1000 mmHg pressure in the bursting test 12 months after grafting. From Dec., 1984, 55 anastomoses in 34 bypass-operations employing autogenous vein grafts were performed using PGA and PDS in 28 cases clinically. There were no anastomotic complications. In conclusion, the synthetic absorbable suture material, especially in the form of monofilament, seems to be most suitable for suturing or anastomosing autogenous small vessels at present. PMID:2552281

Naoe, A

1989-06-01

20

Pyloric exclusion. Suture material of choice.  

Science.gov (United States)

Pyloric exclusion was first reported in 1977 as a temporary method of providing duodenal decompression in an attempt to protect the duodenum in the early postoperative period during the healing phase, followed by the return of normal gastrointestinal transit. It has been adopted by several trauma centers across the country as part of their armamentarium for managing moderate to severe duodenal injuries. Most series report using a polyglycolic acid (PGA) suture in performing the exclusion, anticipating a 3- to 4-week interval before pyloric patency is re-established. A comparison of polypropylene (PP), polyglycolic acid (PGA), and polydioxanone (PDS) sutures in the dog model suggests, however, that only PDS reliably accomplishes this goal. The low (approximately 5-10%) but finite incidence of fistula formation reported with pyloric exclusion using PGA may be improved by using PDS instead. PMID:2827549

DeSantis, M; Devereux, D F; Thompson, D

1987-12-01

 
 
 
 
21

New-Fangled Slowly-Absorbable versus Non-Absorbable Sutures for Abdominal Fascial Closure. Have the Goals towards an Advantageous Suture Been Met?  

Directory of Open Access Journals (Sweden)

Full Text Available Background-Aim: The technique of abdominal closure along with the material to be used is constantly evolving. The aim of the present study is to evaluate differences in midline laparotomy closure with a standard closure technique and new-fangled slow-absorbable versus non-absorbable sutures. Material and Methods: A prospective, comparative study of patients undergoing laparotomy closure with either STARDIOX (Polydioxanone or STARLENE (Polypropylene sutures during a 9 month period was performed. Patients were evaluated and compared in terms of surgical site infection, incisional hernia, burst abdomen, and suture sinus formation. Results: A total of 284 patients were included [141 in the STARDIOX (Polydioxanone group and 143 in the STARLENE (Polypropylene group]. Sinus formation was not noticed and no palpable knots were reported in both groups. Moreover burst abdomen was never encountered. Incisional hernia rates were similar for both suture materials: n = 6 (4.3% for the STARDIOX (Polydioxanone group and n = 5 (3.5% for the STARLENE (Polypropylene group. There was not statistically significant relationship between the type of suture that was used and wound infection: n = 5 (3.5% in the STARDIOX (Polydioxanone group and n = 6 (4.2% in the STARLENE (Polypropylene group. Complications did not occur in 96.1% of all patients. Conclusions: Our study suggests that there are no significant differences between these two new-fangled sutures. It seems that progress of suture materials has led to a step towards the goals of a beneficial suture and from then on complications of surgical wound closure should be merely a matter of operative technique.

Georgios Anthimidis

2013-05-01

22

The sutured Thurston norm  

Digital Repository Infrastructure Vision for European Research (DRIVER)

For sutured 3-manifolds M, there is a sutured Thurston norm due to Scharlemann. We show how depth one foliations of M and corresponding fibrations and the usual Thurston norm on the double of M are useful tools for computing this norm. In many examples, the faces of the unit ball of the sutured norm are related to cones of depth one foliations of M but examples indicate this is not a general relationship.

Cantwell, John; Conlon, Lawrence

2006-01-01

23

Comparison of seven different suture materials in the feline oral cavity.  

Science.gov (United States)

Seven different suture materials were implanted into the oral tissues of 12 cats. The sutures and surrounding tissues were retrieved en bloc from each of two cats on days one, three, seven, 14, 21, and 28 postimplantation. Tissue reaction and suture duration were evaluated by gross visual observation and histological examination. Chromic gut disappeared between days three and seven; polyglactin 910 disappeared between days 14 and 21; and polyglycolic acid disappeared as early as seven to 14 days. Polydioxanone still was intact at day 28 and is recommended as an absorbable material for procedures in which longer healing time is anticipated. All the nonabsorbable suture materials (i.e., polypropylene, stainless steel, and nylon) were intact at day 28 postimplantation. Visual inspection showed polypropylene to have the least tissue reaction. PMID:8680924

DeNardo, G A; Brown, N O; Trenka-Benthin, S; Marretta, S M

1996-01-01

24

Performance of sliding knots in monofilament and multifilament suture material.  

Science.gov (United States)

Three different sliding knots were tested using five recently developed monofilament and multifilament suture materials. The resorbable materials were polyglactin-910 (Vicryl), polyglycolic-acid (Dexon-Plus), polyglyconate (Maxon), and polydioxanone (PDS), and the nonresorbable material was polypropylene (Prolene). For each type of sliding knot, three or five throws of suture were tested. Knot strength was determined by the loop holding capacity, which was defined as the strength at which the knot broke, or at which slippage in the knot amounted to more than 2 mm. When the three kinds of sliding knots were compared, identical sliding knots with identical throws around a single suture were found to be the most unreliable. Nonidentical and parallel sliding knots differed little with respect to knot reliability. Five-throw knots were generally stronger than three-throw knots. However, the effect of adding two extra throws to three-throw sliding knots was only significant if monofilament suture material was used. Comparison of the different suture materials revealed major differences in knot holding ability. These findings indicate that knot strength is dependent on both the type of knot and the type of suture material, and surgeons should be cognizant of these variables. PMID:3016627

Trimbos, J B; Van Rijssel, E J; Klopper, P J

1986-09-01

25

Cobordisms of sutured manifolds  

CERN Document Server

We introduce a natural notion of cobordism between sutured manifolds. Then we construct a map on sutured Floer homology, induced by cobordisms between balanced sutured manifolds. This map is a common generalization of the hat version of the cobordism map in Heegaard-Floer theory, and the contact gluing map recently defined by Honda, Kazez, and Matic. We show that SFH, together with the above cobordism maps, form a type of TQFT in the sense of Atiyah. As a special case, our theory gives rise to a map on link Floer homology, induced by decorated link cobordisms.

Juhasz, Andras

2009-01-01

26

Hypersensitivity to suture anchors.  

Science.gov (United States)

Hypersensitivity to suture anchor is extremely rare. Herein, we present a case in which hypersensitivity to suture anchor was strongly suspected. The right rotator cuff of a 50-year-old woman was repaired with a metal suture anchor. Three weeks after the surgery, she developed erythema around her face, trunk, and hands, accompanied by itching. Infection was unlikely because no abnormalities were detected by blood testing or by medical examination. Suspicious of a metallic allergy, a dermatologist performed a patch testing 6 months after the first surgery. The patient had negative reactions to tests for titanium, aluminum, and vanadium, which were the principal components of the suture anchor. The anchor was removed 7 months after the first surgery, and the erythema disappeared immediately. When allergic symptoms occur and persist after the use of a metal anchor, removal should be considered as a treatment option even if the patch test result is negative. PMID:23956902

Goto, Masafumi; Gotoh, Masafumi; Mitsui, Yasuhiro; Tanesue, Ryo; Okawa, Takahiro; Higuchi, Fujio; Shiba, Naoto

2013-01-01

27

Band taut sutured manifolds  

CERN Document Server

Attaching a 2-handle to a genus two or greater boundary component of a 3-manifold is a natural generalization of Dehn filling a torus boundary component. We prove that there is an interesting relationship between an essential surface in a sutured 3-manifold, the number of intersections between the boundary of the surface and one of the sutures, and the cocore of the 2-handle in the manifold after attaching a 2-handle along the suture. We use this result to show that tunnels for tunnel number one knots or links in any 3-manifold can be isotoped to lie on a branched surface corresponding to a certain taut sutured manifold hierarchy of the knot or link exterior. In a subsequent paper, we use the theorem to prove that band sums satisfy the cabling conjecture, and to give new proofs that unknotting number one knots are prime and that genus is superadditive under band sum. To prove the theorem, we introduce band taut sutured manifolds and prove the existence of band taut sutured manifolds.

Taylor, Scott A

2011-01-01

28

New sutures and suture anchors in sports medicine.  

Science.gov (United States)

Arthroscopic surgery requires appropriate surgical implants for effective fixation of tendons and ligaments to bone. Biodegradable suture anchors are being used with increasing frequency for various procedures in sports medicine. As companions to these biodegradable suture anchors, new sutures have been developed which possess greater strength and different material properties from the conventional braided polyester suture. Biodegradable polymers currently found in sutures and suture anchors include poly-L-lactic acid, poly-D, L lactic acid, polydioxanone, polyglycolic acid and their copolymers. Suture anchors are now available preloaded with a choice of conventional braided polyester sutures or some version of ultrahigh molecular weight polyethylene ("super") sutures. Most new suture anchors come with 2 sutures. The manner in which these sutures are attached to the anchor varies and may consist of 2 separate eyelets or 2 slots either parallel to one another or at different angles to one another. Some anchors have a very large single eyelet that allows for 2 or more sutures. PMID:17135965

Alan Barber, F; Boothby, Michael H; Richards, David P

2006-09-01

29

Selective suture cutting for control of astigmatism following cataract surgery  

Directory of Open Access Journals (Sweden)

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.

Bansal R

1992-01-01

30

Mechanical comparison of 10 suture materials before and after in vivo incubation.  

Science.gov (United States)

The material properties of ten 2-O suture materials were evaluated tensiometrically at time = 0 and again after 6 weeks incubation in rats. All suture material was incubated and tested without knots. Specialized machinery was used with a custom securing apparatus to pull suture material apart at constant speed. Stress-strain curves were derived, and from these strength, toughness, strain at rupture, and elastic modulus were determined. Sutures tested included Vicryl [poly(glycolide-lactide)], Dexon (polyglycolic acid), Ethibond (polyester), silk, plain gut, chromic gut, Maxon (polyglyconate), PDS (polydioxanone), nylon, and Prolene (polypropylene). Elastic modulus was greatest for braided, least for monofilament, and intermediate for gut sutures, regardless of chemical composition (ANOVA, P = 0.0001). Strength, strain, and toughness decreased in all of the sutures over time in vivo with the exception of braided polyester (Ethibond), which remained stable. Silk demonstrated the least strength and toughness while PDS and Maxon were the strongest and toughest at time = 0. Vicryl, Dexon, and gut sutures were absorbed to the point that they could not be tested after 6 weeks in vivo. Performance tables are provided for all sutures. PMID:8152233

Greenwald, D; Shumway, S; Albear, P; Gottlieb, L

1994-04-01

31

Nonabsorbable suture material in cataract surgery: a comparison of Novafil and nylon.  

Science.gov (United States)

We compared the performance of 10-0 Novafil (polybutester, Davis & Geck, American Cyanamid Company, New South Wales, Australia.) with that of 10-0 nylon (Alcon) in 60 patients undergoing extracapsular cataract extraction and implantation of a posterior chamber intraocular lens. A standard technique was used, and the incision was closed with interrupted sutures of either 10-0 Novafil or 10-0 nylon. Length of follow up ranged from 6 to 26 months (average, 15 months). We assessed the intraoperative handling qualities of the suture materials, as well as their effect on wound healing and inflammation. We also compared the surgically-induced astigmatism in the two suture groups over the first 3 postoperative months and then in long-term follow up (average, 15 months). Sutures removed at long-term follow up were examined by scanning electron microscopy (SEM). Both suture materials handled easily at operation and were well tolerated by all patients. There was no significantly different surgically-induced astigmatism in the two suture groups after 12 weeks (P = .962) or during longer follow up (P = .401). SEM confirmed more advanced biodegradation of nylon as compared with Novafil sutures after they had been in place an average of 18 months. PMID:1508484

Seeto, R; Ng, S; McClellan, K A; Billson, F A

1992-08-01

32

Suturas mecânicas Mechanic sutures  

Directory of Open Access Journals (Sweden)

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.

Alexandre Miranda Duarte

2002-10-01

33

Regulation of cranial suture morphogenesis.  

Science.gov (United States)

The cranial sutures are the primary sites of bone formation during skull growth. Morphogenesis and phenotypic maintenance of the cranial sutures are regulated by tissue interactions, especially those with the underlying dura mater. Removal of the dura mater in fetuses causes abnormal suture development and premature suture obliteration. The dura mater interacts with overlying tissues of the cranial vault by providing: (1) intercellular signals, (2) mechanical signals and (3) cells, which undergo transformation and migrate to the suture. The intercellular signaling governing suture development employs the fibroblast growth factors (FGFs). In rats during formation of the sutures in the fetus, FGF-1 is localized mainly in the dura mater, while other FGFs are expressed in the overlying tissues. By birth, FGF-2 largely replaces FGF-1 in the dura mater. FGFs present in the calvaria bind either the IIIb or IIIc mRNA splice variants of the FGF receptors (FGFRs) 1, 2, or 3. Monoclonal antibodies to the b variant of FGFR2 were used to determine the distribution of FGFR2IIIb during suture development and its extracellular localization. FGFR2IIIb is present in association with mature osteoblasts and osteogenic precursor cells of the suture in the fetus. Ectodomains of FGFR2IIIb, the products of proteolytic cleavage of the receptors, were present throughout the extracellular matrix of sutures resisting obliteration (coronal and sagittal), but absent from the core of sutures undergoing normal fusion (posterior intrafrontal). This observation is consistent with a possible mechanism, in which truncated receptors bind FGFs, thus regulating free FGF available to nearby cells. Mechanical signaling in the calvaria results from tensional forces in the dura mater generated during rapid expansion of the neurocranium. Posterior intrafrontal sutures of rats, which fuse between days 16 and 24, were subjected to cyclical tensional forces in vitro. Significant delay in the timing of suture fusion and increases in the expression domains of FGFR1 and 2 were observed, demonstrating the sensitivity of suture patency to mechanical signals and a possible role of the FGF system in mediating such stimuli. Finally, cells of the dura mater beneath the intrafrontal and sagittal sutures were observed to undergo a morphological transformation to a dendritic morphology and migrate into the suture mesenchyme between days 10 and 16 of development. This process may participate in suture and bone morphogenesis and influence the patency of the sutures along the anterior-posterior axis. PMID:14745235

Ogle, Roy C; Tholpady, Sunil S; McGlynn, Kathryn A; Ogle, Rebecca A

2004-01-01

34

The best suture for hypospadias?  

Science.gov (United States)

In a study designed to determine the best suture for use in hypospadias surgery, polydioxanone (PDS), chromic catgut, and polyglycolic acid (Dexon) were studied under similar conditions in the penile foreskin of 16 baboons. Gross and microscopic observations were made at intervals of six to forty-eight days. The wounds sutured with catgut were all healed by twenty-four days with complete suture resorption and no evidence of scar formation. Both polyglycolic acid and polydioxanone sutures showed delayed resorption, wound abscesses, and granulomas. Catgut remains the best available suture to use in the penile foreskin. Polyglycolic acid and polydioxanone sutures, because of their prolonged resorption and excess reaction, should not be used in hypospadias surgery. PMID:3107191

Bartone, F; Shore, N; Newland, J; King, L; DuPlessis, D

1987-05-01

35

Nonabsorbable suture material in corneoscleral sections--a comparison of novafil and nylon.  

Science.gov (United States)

We compared a newly available nonabsorbable monofilament ophthalmic suture, 9/0 Novafil (Davis & Geck), with 10/0 nylon (Alcon), currently the most popular suture for closure of corneoscleral sections. Surgery was performed on nine rats and ten rabbits. In each case a 120 degrees corneoscleral section was made in each eye and closed with interrupted sutures of 9/0 Novafil in one eye and 10/0 nylon in the other. We compared their handling qualities during surgery, as well as their effect on postoperative wound inflammation. In addition we examined the suture material from each eye of the rats by scanning electron microscopy (SEM) after 3 months, and we compared the surgically induced astigmatism in the rabbits in the two suture groups. Both suture materials were easy to handle and well tolerated. Nylon sutures from six of the eight rat eyes studied showed SEM evidence of surface disintegration after 3 months, whereas all the Novafil sutures remained intact. PMID:2779951

McClellan, K A; Knol, A; Billson, F A

1989-07-01

36

Influence of suture regularity on corneal astigmatism after penetrating keratoplasty  

DEFF Research Database (Denmark)

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.

Hjortdal, Jesper; SØndergaard, Anders

2011-01-01

37

Suturas mecânicas / Mechanic sutures  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese [...] Abstract in english 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 surge [...] ry 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.

Alexandre Miranda, Duarte; Elizabeth Gomes dos, Santos.

2002-10-01

38

Radiation resistant polypropylene  

International Nuclear Information System (INIS)

Polypropylene (PP) is used, among other application, for medical devices production. It was applied also for nuclear track membranes and nuclear track filters development beside other materials like polyethylene terephthalate and polycarbonate. The various crystal structure of PP has significant influence on bi-axially oriented PP films 10 ?m thick formation, which is suitable to this application. Modified polypropylene (PP-M) has been obtained in the Institute of Nuclear Chemistry and Technology. This material can be used for production any kind of medical devices. Radicals which are form during PP irradiation are located in crystal phase (stable radicals) and amorphous phase (unstable radicals). Those species have fundamental influence on PP properties after irradiation process. The basic properties of PP-M are described in presented lectures. (author)

39

Releasable suture technique for trabeculectomy  

Directory of Open Access Journals (Sweden)

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.

Thomas Ravi

1997-01-01

40

The Role of Fibrin Glue Polypropylene Mesh Fixation in Open Inguinal Hernia Repair  

Science.gov (United States)

ABSTRACT The aim: of this study was to compare two methods of polypropylene mesh fixation for inguinal hernia repair according to Lichtenstein using fibrin glue and suture fixation. Material and Methods: The study included 60 patients with unilateral inguinal hernia, divided into two groups of 30 patients – Suture fixation and fibrin glue fixation. All patients were analyzed according to: age, gender, body mass index (BMI), indication for surgery–the type, localization and size of the hernia, preoperative level of pain and the type of surgery. Overall postoperative complications and the patient’s ability to return to regular activities were followed for 3 months. Results and discussion: Statistically significant difference in the duration of surgery, pain intensity and complications (p<0.05) were verified between method A, the group of patients whose inguinal hernia was repaired using polypropylene mesh–fibrin glue and method B, where inguinal hernia was repaired with polypropylene mesh using suture fixation. Given the clinical research, this systematic review of existing results on the comparative effectiveness, will help in making important medical decisions about options for surgical treatment of inguinal hernia. Conclusions: The results of this study may impact decision making process for recommendations of methods of treatment by professional associations, making appropriate decisions on hospital procurement of materials, as well as coverage of health funds and insurance. PMID:24937929

Odobasic, Amer; Krdzalic, Goran; Hodzic, Mirsad; Hasukic, Sefik; Sehanovic, Aida; Odobasic, Ademir

2014-01-01

 
 
 
 
41

Microindentation of oriented polypropylene  

Science.gov (United States)

The thesis focuses on the measurement of conventional engineering mechanical properties like yield strength, and dynamic mechanical (viscoelastic) properties of polymers using microindentation. In order to obtain high spatial resolutions, a flat punch indenter with a relatively small diameter of 80 mum was used. The present work emphasizes anisotropic materials: in particular oriented polypropylene. The initial test material was prepared by two solid state forming processes: uniaxial tensile drawing at elevated temperatures, and channel die forming. The latter allowed for greater control of the deformation ratio during forming over a much wider range of tensile strains. The mechanism of deformation under the tip of the indenter was studied using optical microscopy of thin sections viewed in transmission. The deep penetration mechanism changed with direction of indentation relative to the orientation axis. The observations were consistent with the mechanisms observed for unidirectional fiber reinforced composites. In particular, when penetrated parallel to the orientation direction, sharply defined zones of deformation which were similar to kink bands seen in compressed composites were seen. Detailed analysis of this behaviour showed that a modified version of the kink band formation theories developed for fiber composites could be successfully applied to oriented polypropylene. To confirm this, experiments on oriented polypropylene were compared to similar experiments on unidirectional carbon fiber reinforced epoxy. The development of deformation during deep penetration could be monitored by using a dynamic mechanical test which measured the stress amplitude response to an applied oscillating strain. One possible interpretation of these experimental observations involved the progressive development of the kink band deformation structure as the indenter was pushed into the material. The results of the first part of the thesis were used in a practical application: namely the measurement of the gradient of mechanical properties in the near surface region of a processed polypropylene. For this, a novel processing method was developed in which a strain gradient was produced in the near surface region of the material. The tensile strain gradation resulted in a corresponding gradient in mechanical properties. The micro indentation dynamic mechanical test was used to measure this variation in near surface properties. The usefulness of the microindentation test to measure local variations in viscoelastic properties was thus demonstrated on a scale which is similar to that expected in many processed plastics.

Lo, James C. W.

42

Influence of suture technique and suture material selection on the mechanics of end-to-end and end-to-side anastomoses.  

Science.gov (United States)

Experiments were performed in dogs to evaluate the mechanics of 26 end-to-end and 42 end-to-side artery-vein graft anastomoses constructed with continuous polypropylene sutures (Surgilene; Davis & Geck, Division of American Cyanamid Co., Danbury, Conn.), continuous polybutester sutures (Novafil; Davis & Geck), and interrupted stitches with either suture material. After construction, the grafts and adjoining arteries were excised, mounted in vitro at in situ length, filled with a dilute barium sulfate suspension, and pressurized in 25 mm Hg steps up to 200 mm Hg. Radiographs were obtained at each pressure. The computed cross-sectional areas of the anastomoses were compared with those of the native arteries at corresponding pressures. Results showed that for the end-to-end anastomoses at 100 mm Hg the cross-sectional areas of the continuous Surgilene anastomoses were 70% of the native artery cross-sectional areas, the cross-sectional areas of the continuous Novafil anastomoses were 90% of the native artery cross-sectional areas, and the cross-sectional areas of the interrupted anastomoses were 107% of the native artery cross-sectional areas (p < 0.05). At physiologic pressures, there were no differences in compliance among the three types of anastomosis. These data suggest that when constructing an end-to-end anastomosis in a small vessel, one should use an interrupted suture line or possibly continuous polybutester suture. Forty-two end-to-side anastomoses demonstrated no differences in cross-sectional areas or compliance for the three suture techniques. This suggests that, unlike with end-to-end anastomoses, when constructing an end-to-side anastomosis in patients any of the three suture techniques may be acceptable. PMID:8622304

Baumgartner, N; Dobrin, P B; Morasch, M; Dong, Q S; Mrkvicka, R

1996-05-01

43

Mechanical performance of monofilament synthetic absorbable sutures.  

Science.gov (United States)

The purpose of this study was to evaluate the mechanical performance of two new synthetic monofilament absorbable sutures. The polydioxanone sutures is prepared by polymerizing and extruding the monomer, paradioxanone, in the presence of a suitable catalyst. The other suture is a modified polyglycolic acid suture, made by reacting trimethylene carbonate and glycolide. The knot configuration (1 = 1 = 1, 1 x 1 x 1, and 2 = 1 = 1) required for knot security was identical for the two synthetic monofilament sutures. The mean knot breaking strengths for the polydioxanone and modified polyglycolic acid sutures did not differ significantly. The surfaces of these sutures exhibited a low coefficient of friction which was slightly increased by hydration. The most distinctive difference between the handling characteristics of these two sutures was their flexural rigidity. The stiffness of the polydioxanone suture was 60 percent greater than that of the modified polyglycolic acid suture. PMID:3118727

Rodeheaver, G T; Powell, T A; Thacker, J G; Edlich, R F

1987-11-01

44

Comparison of two techniques: interrupted mass closure and continuous mass closure with polypropylene in laparotomy  

International Nuclear Information System (INIS)

Wound dehiscence is an acute wound failure. It commonly presents about one week after surgery and may be preceded by a serosanguinuous discharge. Wound dehiscence is an important cause of postoperative morbidity and mortality. To compare the early postoperative complications of closure of laparotomy wound by interrupted mass closure and continuous mass closure techniques. Sixty patients were included in this study and divided in two groups; group A and group B. Closure of laparotomy wound with monofilament polypropylene No.1 suture by interrupted mass closure technique for group A and continuous mass closure technique with same suture material in group B was done. In group A, 2 patients developed wound infection and 1 patient was found with wound dehiscence, while in group B, 3 patients suffered wound infection and 2 patients developed wound dehiscence. The closure of laparotomy wound by interrupted mass closure technique with polypropylene No.1 is better closure technique with low rate of wound infection and wound dehiscence as compared to continuous suturing technique with same suture material. (author)

45

New bactericidal surgical suture coating.  

Science.gov (United States)

This paper demonstrates the effectiveness of a new antimicrobial suture coating. An amphiphilic polymer, poly[(aminoethyl methacrylate)-co-(butyl methacrylate)] (PAMBM), inspired by antimicrobial peptides, was bactericidal against S. aureus in time-kill experiments. PAMBM was then evaluated in a variety of polymer blends using the Japanese Industrial Standard (JIS) method and showed excellent antimicrobial activity at a low concentration (0.5 wt %). Using a similar antimicrobial coating formula to commercial Vicryl Plus sutures, disk samples of the coating material containing PAMBM effectively killed bacteria (98% reduction at 0.75 wt %). Triclosan, the active ingredient in Vicryl Plus coatings, did not kill the bacteria. Further Kirby-Bauer assays of these disk samples showed an increasing zone of inhibition with increasing concentration of PAMBM. Finally, the PAMBM-containing coating was applied to sutures, and the morphology of the coating surface was characterized by SEM, along with Vicryl and uncoated sutures. The PAMBM-containing sutures killed bacteria more effectively (3 log(10) reduction at 2.4 wt %) than Vicryl Plus sutures (0.5 log(10) reduction). PMID:22877364

Li, Yan; Kumar, Kushi N; Dabkowski, Jeffrey M; Corrigan, Meagan; Scott, Richard W; Nüsslein, Klaus; Tew, Gregory N

2012-08-21

46

Comparative study of skin wound closure with polybutester (Novafil) and polypropylene.  

Science.gov (United States)

A prospective study of skin wound closure using polybutester (Novafil) and polypropylene was carried out in 100 elective procedures in 77 patients over a 1-year period at the Plastic Surgery Unit of Mubarak Al Kabeer Hospital, Kuwait. In this comparative study based on clinical evaluation, particular note was made of the handling characteristics of the suture material, wound infection, healing and eventual scar in each case. The tensile strength of both sutures was comparable and the wound infection rate and wound healing characteristics in the two groups were more or less the same. Our study has shown Novafil to be a superior suture for skin wound closure because of its handling qualities, easier removal from the healed wound and because of a cosmetically better scar in a significant number of patients. PMID:2810182

Bang, R L; Mustafa, M D

1989-08-01

47

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

48

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

LENUS (Irish Health Repository)

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.

Hennessey, D B

2012-08-01

49

Novafil. A dynamic suture for wound closure.  

Science.gov (United States)

Abdominal wound dehiscence was quantitatively studied in a rat model. Polybutester suture is a new monofilament nonabsorbable suture that has unique stress-strain properties that are potentially beneficial for abdominal wound closure. The abdominal volume at the moment of wound dehiscence was correlated with the extensibility of the suture material used for closure. Interrupted sutures of polybutester cut through the tissues at a mean abdominal volume of 212 +/- 3 ml. This volume was significantly (p less than or equal to 0.005) greater than the mean volumes reached with nylon (197 +/- 3 ml) or polyglycolic acid (187 +/- 4 ml). Closure of abdomens with continuous polybutester suture resulted in a mean rupture volume of 218 +/- 3 ml, which was significantly (p less than or equal to 0.005) greater than that achieved with the same suture employed as simple interrupted sutures (212 +/- 4 ml). The influence of width of tissue bite, suture size, and needle configuration was also evaluated. PMID:3017248

Rodeheaver, G T; Nesbit, W S; Edlich, R F

1986-08-01

50

Polypropylene-Process selection criteria  

Energy Technology Data Exchange (ETDEWEB)

Production based on traditional catalysts involved, after the polymerization reaction, catalyst residues removal (deashing) and separation of isotactic polypropylene (desired product) from atactic polypropylene (low-value product). The deashing reaction poisoned the unreacted monomers and any solvents, requiring purification of these before recycle to the reaction. An effluent treatment section was also needed. The new catalysts developed by Montedison* in cooperation with Mitsui Petrochemicals in the last few years allow the polymer structure, yield, selectivity and morphology to be controlled in the reaction stage. The production processes have therefore been drastically simplified. In addition, the complete control over catalysis has resulted in remarkable quality improvements and in an expanded product range.

Di Drusco, G.; Rinaldi, R.

1984-11-01

51

Oral tissue reactions to suture materials.  

Science.gov (United States)

Tissue reactions to natural and synthetic braided and monofilament suture materials in gingiva and oral mucosa were studied. A total of 138 sutures made of four commonly used materials were placed in the edentulous ridges and vestibular mucosa of eight beagle dogs. Biopsy specimens including the suture loop and surrounding tissues were obtained after 3, 7, and 14 days and processed for histologic analysis. The inflammatory reaction was more rapid and intense than the reaction that has been reported after suture placement in skin. Bacterial invasion of the suture track was a common sequela regardless of the material used, but it was particularly prominent for silk. The formation of a perisutural epithelial sleeve was well under way at 3 days and in some instances included the entire suture track within 7 days. Connective tissue reactions consisted of several well-defined, concentric perisutural zones. At 14 days, these zones were partly replaced by granulation tissue surrounded by a fibrous capsule. The synthetic monofilament suture elicited a mild inflammatory tissue response. The results showed that sutures placed in gingiva and oral mucosa produce a prolonged tissue response that is most likely a result of the continual influx of microbial contamination along the suture channel, which may be a lesser problem when sutures are placed in other surgical compartments. The results indicate that chromic gut sutures are rapidly and unpredictably absorbed when used in an environment characterized by moisture and infectious potential. PMID:10093524

Selvig, K A; Biagiotti, G R; Leknes, K N; Wikesjö, U M

1998-10-01

52

Inflammatory synovial fluid and absorbable suture strength.  

Science.gov (United States)

The effect of inflammatory synovial fluid upon several absorbable sutures commonly used for meniscus repair was studied by implanting lengths of these sutures into unstable, arthritic rabbit knees and, after varying lengths of time (1-6 weeks), testing their breaking strength. Both polyglactin-910 (Vicryl) and polyglycolic-acid (Dexon) sutures retained only minimal breaking strength 3 weeks after implantation. Chromic gut sutures demonstrated a steady reduction in breaking strength until they retained only 6% of their original strength at 5 weeks and none at 6 weeks. Polydioxanone (PDS) sutures began to lose breaking strength at 2 weeks and retained only 40% of their original strength 5 weeks after implantation. The rate of loss in polydioxanone breaking strength was faster in inflammatory synovial fluid than previously reported in the normal synovial joint. Braided polyester sutures (Mersiline) showed no loss of breaking strength over the duration of this test. While the choice of suture is only one variable influencing the outcome of a meniscus repair, this study demonstrates that only polydioxanone and green braided polyester sutures retain any strength 6 weeks after implantation (the time of immobilization commonly recommended for meniscal repairs). Complete meniscal healing can require several months. In the absence of compelling evidence to the contrary, the use of nonabsorbable suture materials for meniscal repair seems the most appropriate choice. PMID:3233117

Barber, F A; Gurwitz, G S

1988-01-01

53

Geometrically controlled tensile response of braided sutures.  

Science.gov (United States)

Sutures are the materials used for wound closure that are caused by surgery or trauma. The main pre-requisite to the success of the suture is to obtain ultimate level of tensile properties with defined geometrical constraints. In this communication, the model for tensile properties of braided sutures has been proposed by elucidating the most important geometrical and material parameters. The model has accounted for the kinematical changes occurring in the braid and constituent strand geometries under defined level of strain. A comparison has been made between the theoretical and experimental results of stress-strain characteristics of braided sutures. PMID:25579946

Rawal, Amit; Sibal, Apurv; Saraswat, Harshvardhan; Kumar, Vijay

2015-03-01

54

Radiolytic oxidation of national polypropylene  

International Nuclear Information System (INIS)

National polypropylene studied in this paper is isotatic, thermoplastic and partially crystalline. It is used in the medical supplies fabrication which must be sterilized before using. The radiosterilization is a commercial process employed world-widely. It happens at room temperature and in the air presence taking effect of the radiolytic oxidation besides another degradation process specially if the polymer was not protected adequately. The radiolytic oxidation was investigated by infrared spectroscopy. The polypropylene samples were irradiated by gamma rays from 60 Co source at doses up to 255 kGy. The infrared spectra showed the presence of phenolic antioxidant and the occurrence of the radiolytic oxidation from 100 kGy and the formation of carbonyl group and water. (author). 13 refs., 5 figs., 1 tab

55

Positron irradiation effects on polypropylene  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Positron irradiation effects on polypropylene (PP) and polyethylene during the positron lifetime measurements have been studied in detail. The effect, which was to decrease I3, has been found to be larger in air than in vacuum. For PP, when the lifetime measurements were performed at temperatures above 348K, the radiation effect was scarcely observable. However at low temperature the radiation effect was accumulated and I3 was decreased during the measurements. Irradiation of Co-60 ?-ray up ...

Suzuki, T.; Miura, T.; Oki, Y.; Numajiri, M.; Kondo, K.; Ito, Y.

1993-01-01

56

21 CFR 878.5020 - Nonabsorbable polyamide surgical suture.  

Science.gov (United States)

...2010-04-01 false Nonabsorbable polyamide surgical suture. 878.5020 Section...Devices § 878.5020 Nonabsorbable polyamide surgical suture. (a) Identification. Nonabsorbable polyamide surgical suture is a...

2010-04-01

57

Carbon dioxide laser-assisted nerve repair: effect of solder and suture material on nerve regeneration in rat sciatic nerve.  

Science.gov (United States)

In order to further improve and explore the role of lasers for nerve reconstruction, this study was designed to investigate regeneration of sharply transected peripheral nerves repaired with a CO(2) milliwatt laser in combination with three different suture materials and a bovine albumin protein solder as an adjunct to the welding process. Unilateral sciatic nerve repair was performed in 44 rats. In the laser group, nerves were gently apposed, and two stay sutures (10-0 nylon, 10-0 polyglycolic acid, or 25 microm stainless steel) were placed epi/perineurially. Thereafter, the repair site was fused at 100 mW with pulses of 1.0 s. In the subgroup of laser-assisted nerve repair (LANR), albumen was used as a soldering agent to further reinforce the repair site. The control group consisted of nerves repaired by conventional microsurgical suture repair (CMSR), using 4-6 10-0 nylon sutures. Evaluation was performed at 1 and 6 weeks after surgery, and included qualitative and semiquantitative light microscopy. LANR performed with a protein solder results in a good early peripheral nerve regeneration, with an optimal alignment of nerve fibers and minimal connective tissue proliferation at the repair site. All three suture materials produced a foreign body reaction; the least severe was with polyglycolic acid sutures. CMSR resulted in more pronounced foreign-body granulomas at the repair site, with more connective-tissue proliferation and axonal misalignment. Furthermore, axonal regeneration in the distal nerve segment was better in the laser groups. Based on these results, CO(2) laser-assisted nerve repair with soldering in combination with absorbable sutures has the potential of allowing healing to occur with the least foreign-body reaction at the repair site. Further experiments using this combination are in progress. PMID:12740882

Menovsky, Tomas; Beek, Johan F

2003-01-01

58

Needle and suture contamination in strabismus surgery  

Directory of Open Access Journals (Sweden)

Full Text Available 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 least one positive specimen. 8.3% of the needles and 15% of the sutures were culture positive. In all culture positive specimens 40% of the needles and 55% of the sutures produced 3 or less colony forming units (CFU. 4-6 CFU in 20% of needles and 11% of sutures, 7 or more CFU in 40% of needles and 34% of sutures were demonstrated accordance with dilution scheme. Coagulase-negative staphylococci were overwhelmingly predominated. Conclusion: The amount of bacterial contamination is usually below the level known to produce endophthalmitis in strabismus surgery. Needles and sutures used in strabismus surgery can become contaminated during surgery despite povidine-iodine usage. Needles and sutures with high contamination could potentially cause postoperative intraocular infection.

Betül Tu?cu

2007-01-01

59

Using Novafil: would it make suturing easier?  

Science.gov (United States)

The use of monofilament nonabsorbable suture materials is not common in Dentistry. Although it is known that multifilament suture materials induce greater cellular reaction, most Dentists prefer to use cotton and silk. Rigidity and package memory are disadvantages of monofilament nonabsorbable suture materials. A new material, Polybutester (Novafil), has been used successfully in Medicine but its use is not common in Dentistry. Seventy male and female Wistar rats were used to study the clinical response of skin and abdominal wall muscle to the use of Novafil and nylon sutures. Under general anesthesia, standard wounds were created in the dorsum and abdomen of the animals and sutured with either Novafil or nylon. The animals were sacrificed immediately, 12, 24, and 72 hours and at 4, 5 and 7 days to evaluate the clinical aspect of both wounds. Polybutester presented some advantages such as strength, lack of package memory, elasticity and flexibility which made suturing quicker and easier. Some subjects presented abdominal wound edema during the period and six animals developed infection of abdominal wounds within seven days. These initial findings show that Novafil is easy to handle and would be better tolerated in the mouth than nylon resulting in less discomfort for the patient. Novafil can be used safely on skin and mucosal wounds and, if necessary, it can be used in internal sutures because it irritates less than nylon. PMID:9485633

Pinheiro, A L; de Castro, J F; Thiers, F A; Cavalcanti, E T; Rêgo, T I; de Quevedo, A S; Lins, A J; Aca, C R

1997-01-01

60

Effects of primary suture and fib sealant on hemostasis and liver regeneration in an experimental liver injury  

Directory of Open Access Journals (Sweden)

Full Text Available AIM: To investigate the effects of fib sealant on hemostasis and liver regeneration and intra-abdominal adhesions in an experimental liver injury.METHODS: Thirty-six Wistar rats were randomly divided into primary suture group (n = 15, fib sealant group (n = 15 and control group (n = 6. A wedge resection was performed on the left lobe of the liver. In primary suture group, liver was sutured using polypropylene material, while fib glue was administrated on the liver surface in fib sealant group.RESULTS: More intra-abdominal adhesions were observed in the primary suture group compared to the fib sealant group on 3rd (2.50 ± 0.5 vs 0.25 ± 0.5, P = 0.015, 10th (2.75 ± 0.5 vs 0.50 ± 0.6, P = 0.06 and 20th (1.75 ± 0.5 vs 0.70 ± 0.5, P = 0.015 postoperative days. Histopathological scores were better in the fib sealant group in comparison with the primary suture group on 3rd (8.75 ± 0.5 vs 6.75 ± 0.5, P = 0.006, 10th (7.50 ± 1.0 vs 5.5 ± 0.6, P = 0.021 and 20th (6.40 ± 1.7 vs 3.20 ± 1.6, P = 0.025 postoperative days.CONCLUSION: Out data suggest that fib sealant is preferred over primary suture in appropriate cases including liver trauma since it causes less intra-abdominal adhesions while allowing shorter hemostasis time as assessed in experimental liver trauma.

Arif Hakan Demirel, Ozgur Taylan Basar, Ali Ulvi Ongoren, Erkut Bayram, Mustafa Kisakurek

2008-01-01

 
 
 
 
61

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

Science.gov (United States)

...made of polypropylene, polyethylene terephthalate, or polytetrafluoroethylene...made of polypropylene, polyethylene terephthalate, or polytetrafluoroethylene...made of polypropylene, polyethylene terephthalate, or...

2010-04-01

62

Suture versus mesh repair for incisional hernia.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

OBJECTIVES To compare suture with mesh repair, for incisional hernia in terms of early and late outcomes. METHODS We reviewed the records of all the patients who presented with primary or recurrent incisional hernia in the Department of General Surgery, Riyadh Medical Complex, Riyadh, Kingdom of Saudi Arabia, from January 2000 to December 2004. We divided patients, who underwent repair, in 2 groups: Group A (suture repair) and Group B (...

Al-salamah, Saleh M.; Hussain, Muhammad I.; Kamran Khalid; Al-akeely, Muhammed H.

2006-01-01

63

Histopathological evaluation of rotation sutures for involutional entropion.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rotation sutures are a popular method of temporarily correcting involutional entropion. The permanence of the procedure depends on a fibrotic scar along the suture tracks. Sutures which create generous scars would probably produce the most satisfactory results. In this study 4-0 chromic gut, nylon, and silk sutures were evaluated in rabbit lower eyelids for their ability to create histologically demonstrable fibrous tracks. All three sutures incited inflammatory cells and fibroblastic activit...

Seiff, S. R.; Kim, M.; Howes, E. L.

1989-01-01

64

[Suture material and suturing of the laparotomy wound in horses and cattle].  

Science.gov (United States)

Wound healing is discussed in the introduction. Subsequently in a review of the suture materials used in large animal laparotomies is presented. In the discussion examples are given of the suture materials that are used at the Department of General and Large Animal Surgery. PMID:7785041

van der Zaag, E J; Klein, W R

1995-06-01

65

Skin closure in vascular neurosurgery: A prospective study on absorbable intradermal suture versus nonabsorbable suture  

Science.gov (United States)

Background: The craniotomy performed with minimal hair removal and closure with intradermal suture alone is an option in neurosurgical procedures, which can help faster psychological recovery of the patient, as it allows a better cosmetic result. This study is aimed at evaluating if such method is safe and effective, compared with continuous skin sutures with 2-0 nylon. Methods: We analyzed the sutures in 117 patients undergoing craniotomies for cerebral aneurysm clipping. In the case group (n = 49), closure of the scalp was performed only with intradermal absorbable sutures using wire Monocryl® 2-0. In the control group (n = 68), closure was performed with continuous suture using 2-0 nylon. Results: The case group was composed of 49 patients in whom just intradermal suture was performed. One (2.2%) patient developed wound infection and was given proper medical treatment. No cases of dehiscence or cerebrospinal fluid leaks were observed. The control group was composed of 68 patients in whom the skin was closed with 2-0 nylon continuous suture. Three (5.3%) patients developed wound infection and were given proper medical treatment. There were no cases of wound dehiscence. The overall infection rate in the control group was 4%. There was no statistically significant difference in the number of wound infections between the two groups (P = 0.73). Conclusion: The closure with intradermal suture alone in craniotomies is as safe as the traditional skin closure with nylon sutures, besides eliminating the need for suture removal and providing a cosmetic advantage. PMID:23050208

Pereira, Julio Leonardo Barbosa; Vieira, Gerival; de Albuquerque, Lucas Alverne Freitas; Mendes, George de Albuquerque Cavalcanti; Salles, Ludmila Rezende; de Souza, André Felipe Ferreira; Dellaretti, Marcos; de Sousa, Atos Alves

2012-01-01

66

Acute Airway Obstruction from a Suture Granuloma  

Directory of Open Access Journals (Sweden)

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.

Jawad Khan

2010-03-01

67

Laparoscopic fascial suture repair of parastomal hernia.  

Science.gov (United States)

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. Mesh repair can be either open or laparoscopic. The recurrence rate and complications of parastomal hernia repair remain very high. We have invented a simple fascial suture laparoscopic repair of parastomal hernia with the use of the Crochet hook needle (EndoClose). This new technique may result in reduced pain, earlier discharge from hospital and reduced risk of infection as there is no mesh used as well as reduced risk of seroma formation. PMID:23780775

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

2013-01-01

68

Double suture technique to delineate PASTA lesions.  

Science.gov (United States)

A common method of treating PASTA (partial articular surface tendon avulsion) lesions involves completing the tear followed by arthroscopic repair. Frequently, the boundaries of the tear are difficult to determine from the bursal side with the use of a single marking stitch. Therefore, we describe a simple technique that allows the surgeon to reproducibly define the boundaries of the partial tear. Following a standard arthroscopic examination of the articular portion of the shoulder joint, the PASTA lesion is identified. A spinal needle is introduced and the most anterior and posterior aspects of the tear are marked by passing 2 sutures. Following a bursectomy, the 2 sutures that clearly define the boundaries of the tear are identified. The tear is then completed by "connecting the dots" outlined by the sutures and an arthroscopic repair is performed in the standard manner. PMID:16762713

Sperling, John W; Dahm, Diane L

2006-06-01

69

Flexor Tenorrhaphy Using Absorbable Suture Materials  

Directory of Open Access Journals (Sweden)

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.

Hyung Joo Kang

2012-07-01

70

Polypropylene nanogel: “Myth or reality”  

International Nuclear Information System (INIS)

The objective of this work is the investigation of the nanogel and microgel formation in modified PP. The modified PP in pellets was synthesized by gamma irradiation of pristine PP under a crosslinking atmosphere of acetylene in dose of 5, 12.5 and 20 kGy, followed by thermal treatment for radical recombination and annihilation of the remaining radicals. The thin film gel of the polypropylenes was obtained by extraction in boiling xylene for period of 12 h at 138 °C, followed by decantation in beaker at room temperature of 25 °C with the total volatilization of the xylene and deposition of dried material film on glass substrate under agitation by Settling process. The thin film gel formed of pristine PP and modified PP (i.e., irradiated) was characterized using scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and differential scanning calorimetry (DSC). The PP morphology indicated the nanogels and microgel formation with increase of spherulitic concentration and crystallinity at dose of 12.5 kGy. - Highlights: ? The formation of nanogels comes from irradiated sites prior to crosslink bonds. ? Evolution of nanogels in size creates domains with lower crosslink density and defects. ? In conclusion nanogel is present in the irradiated PP and has crystallinity.

71

Polypropylene nanogel: “Myth or reality”  

Science.gov (United States)

The objective of this work is the investigation of the nanogel and microgel formation in modified PP. The modified PP in pellets was synthesized by gamma irradiation of pristine PP under a crosslinking atmosphere of acetylene in dose of 5, 12.5 and 20 kGy, followed by thermal treatment for radical recombination and annihilation of the remaining radicals. The thin film gel of the polypropylenes was obtained by extraction in boiling xylene for period of 12 h at 138 °C, followed by decantation in beaker at room temperature of 25 °C with the total volatilization of the xylene and deposition of dried material film on glass substrate under agitation by Settling process. The thin film gel formed of pristine PP and modified PP (i.e., irradiated) was characterized using scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and differential scanning calorimetry (DSC). The PP morphology indicated the nanogels and microgel formation with increase of spherulitic concentration and crystallinity at dose of 12.5 kGy.

Oliani, W. L.; Parra, D. F.; Riella, H. G.; Lima, L. F. C. P.; Lugao, A. B.

2012-09-01

72

Polypropylene nanogel 'myth or reality'  

International Nuclear Information System (INIS)

Complete text of publication follows. The objective of this work is to study the formation of nanogel and microgel in modified PP. The modified PP in pellets was synthesized by gamma irradiation of pristine PP under a crosslinking atmosphere of acetylene in dose of 12.5 kGy, followed by thermal treatment for radical recombination and annihilation of the remaining radicals. The thin film gel of the polypropylenes was obtained by extraction in boiling xylene for period of 12 h at 138 deg C, followed by decantation in becker at room temperature of 25 deg C with the total volatilization of the xylene and deposition of dried material film on fine glass blades under agitation by Settling process. The thin film gel formed of pristine PP and modified (i.e., irradiated) was characterized using scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and differential scanning calorimetry (DSC). The PP morphology indicated the nanogels and microgel formation with increase of spherulitic concentration and crystallinity at dose 12.5 kGy. Acknowledgement. The authors thank FAPESP, CAPES for grants, CCTM/IPEN, for microscopy analysis SEM, Eleosmar Gasparin for DSC analysis and Embrarad/CBE for irradiating the samples.

73

Argon plasma irradiation of polypropylene  

International Nuclear Information System (INIS)

Polypropylene samples were exposed to argon plasma discharge and the changes of the PP surface properties were studied by different methods. Surface wettability was derived from contact angle measured by standard goniometry and chemical structure of the plasma modified PP was studied using X-ray photoelectron spectroscopy (XPS) and by Rutherford backscattering spectroscopy (RBS), surface morphology and roughness of samples using AFM. Zeta potential of pristine and modified PP was determined with the SurPASS. The presence of incorporated oxygen in the PP surface layer, about 60 nm thick, was observed in RBS spectra. Oxygen concentration is a decreasing function of the depth. With progressing aging time the oxygen concentration on the PP surface decreases. Plasma treatment results in a rapid decrease of the contact angle, which increases again with increasing aging time. In XPS measurement the oxygen containing structures, created by the plasma treatment, were found on the very surface of the modified PP and the zeta potential being changed too. The significant difference in zeta potential between pristine and plasma treated PP clearly indicates that the plasma treatment leads to a more hydrophilic PP surface.

74

Optimal Suturing Technique and Number of Sutures for Surgical Implantation of Acoustic Transmitters in Juvenile Salmonids  

Energy Technology Data Exchange (ETDEWEB)

The size reduction of acoustic transmitters has led to a reduction in the length of incision needed to implant a transmitter. Smaller suture knot profiles and fewer sutures may be adequate for closing an incision used to surgically implant an acoustic microtransmitter. As a result, faster surgery times and reduced tissue trauma could lead to increased survival and decreased infection for implanted fish. The objective of this study was to assess the effects of five suturing techniques on mortality, tag and suture retention, incision openness, ulceration, and redness in juvenile Chinook salmon Oncorhynchus tshawytscha implanted with acoustic microtransmitters. Suturing was performed by three surgeons, and study fish were held at two water temperatures (12°C and 17°C). Mortality was low and tag retention was high for all treatments on all examination days (7, 14, 21, and 28 days post-surgery). Because there was surgeon variation in suture retention among treatments, further analyses included only the one surgeon who received feedback training in all suturing techniques. Incision openness and tissue redness did not differ among treatments. The only difference observed among treatments was in tissue ulceration. Incisions closed with a horizontal mattress pattern had more ulceration than other treatments among fish held for 28 days at 17°C. Results from this study suggest that one simple interrupted 1 × 1 × 1 × 1 suture is adequate for closing incisions on fish under most circumstances. However, in dynamic environments, two simple interrupted 1 × 1 × 1 × 1 sutures should provide adequate incision closure. Reducing bias in survival and behavior tagging studies is important when making comparisons to the migrating salmon population. Therefore, by minimizing the effects of tagging on juvenile salmon (reduced tissue trauma and reduced surgery time), researchers can more accurately estimate survival and behavior.

Deters, Katherine A.; Brown, Richard S.; Boyd, James W.; Eppard, M. B.; Seaburg, Adam

2012-01-02

75

Joining and gluing sutured Floer homology  

CERN Document Server

We give a partial characterization of bordered Floer homology in terms of sutured Floer homology. The bordered algebra and modules are direct sums of certain sutured Floer complexes. The algebra multiplication and algebra action correspond to a new gluing map on SFH. It is defined algebraically, and is a special case of a more general "join" map. In a follow-up paper we show that this gluing map can be identified with the contact cobordism map of Honda-Kazez-Matic. The join map is conjecturally equivalent to the cobordism maps on SFH defined by Juhasz.

Zarev, Rumen

2010-01-01

76

Polydioxanone suture in the gastrointestinal tract  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A randomized prospective trial was undertaken of polydioxanone suture (PDS) versus conventional suture material in 98 patients undergoing anastomoses in the gastrointestinal tract. Nine patients died within 6 months of surgery, one of these being related to an anastomotic leak. All other patients were followed up for between one and three and a half years. In 57 colonic anastomoses, 30 were randomized to a single layer of 2/0 (BPC) interrupted PDS and 27 to a single of 2/0 (BPC) interrupted s...

Gillatt, D. A.; Corfield, A. P.; May, R. E.; Bartolo, D. C.; Leaper, D. J.

1987-01-01

77

Haemostatic treatment of a bleeding hepatocarcinoma by polypropylene mesh wrapping in a cirrhotic patient.  

Science.gov (United States)

Spontaneous rupture of hepatocarcinoma (HCC) in a cirrhotic patient is a serious complication with a high incidence of mortality. The pathogenesis of this complication is unknown. Several hypotheses have been proposed in the literature worldwide. The diagnosis, in the absence of specific symptoms, is made by ultrasound, sometimes followed by a CT scan, and finally by exploratory paracentesis. An angiogram is performed to locate the site of the bleeding and possibly allow transcatheter arterial chemo-embolisation. Therapeutic options include one-stage or delayed resection, packing for sub-diaphragmatic bleeding HCC's, and hepatic artery ligation. Suture ligation of the bleeding source is usually impossible due to the friability of the tumor. No sizeable experience with the use of alcoholisation for haemostasis has been reported to date. We report a case of HCC bleeding from segment VI successfully treated by manual compression and placement of a polypropylene mesh (Biomesh P1, Cousin Biotech). PMID:11200006

Donataccio, M; De Bonis, A; Tatulli, F; Cuttitta, A

2000-01-01

78

A simple device for loading radioactive seeds into absorbable sutures  

International Nuclear Information System (INIS)

Radioactive I-125 seeds that are loaded into absorbable sutures are convenient for permanent or removable interstitial-implantation. A simple device for loading radioactive seeds into commercially available sutures is described. This loader permits fast placement of seeds in the suture with minimal exposure to the involed personnel. Variable spacing is accomplished either by absorbable spacers or by minor manipulation of the loaded suture

79

Comparison of suture types in the closure of scalp wounds.  

LENUS (Irish Health Repository)

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.

Bonham, Joseph

2011-06-01

80

A modified suture technique for plastic periodontal and implant surgery--the double-crossed suture.  

Science.gov (United States)

To enable uneventful and accelerated healing processes to occur, common techniques in plastic periodontal and implant surgery focus on stable postoperative flap positions. Flap stability is, in particular, positively influenced by an adequate suturing technique, which therefore represents one important factor with regard to the predictability of successful treatment outcomes. The following article illustrates the use of a modified suturing technique, which aims to improve wound adaptation and soft tissue stabilization after surgical treatment with tunneling flap preparation techniques. Anchored at the incisal contact points of the affected teeth, the suture is crossed through the buccal as well as through the palatal aspect. In this manner, the suture maintains the surgically established coronal displacement of the buccal flap and provides a stable and intimate contact to the underlying tissues. PMID:20111759

Zuhr, Otto; Rebele, Stephan F; Thalmair, Tobias; Fickl, Stefan; Hürzeler, Markus B

2009-01-01

 
 
 
 
81

Resistance forces acting on suture needles.  

Science.gov (United States)

Understanding the resistance forces encountered by a suture needle during tissue penetration is important for the development of robotic surgical devices and virtual reality surgical simulators. Tensile forces applied to skin and tendon during suturing were measured. Fresh sheep achilles tendons were tensioned with a static load 4.9 N, 9.8 N or 19.6 N and sheepskin with 0.98 N, 2.9 N or 4.9 N static load. A straight 2/0 cutting suture needle in series with a load cell on a materials testing machine penetrated the tissue at 90 degrees with a velocity of 1, 5 or 10mm/s for each tissue tension (n=5). Continuous load versus displacement data was obtained and penetration load and stiffness were noted. The load versus displacement curve for skin during needle penetration demonstrated two characteristic peaks, corresponding to initial penetration and emergence of needle from the undersurface of the tissue. Increasing the tension within the tissue (skin and tendon) increased the amount of force required to penetrate the tissue with a suture needle (p<0.05). Needle displacement rate did not affect the resistance to needle penetration (p<0.05). This study provides a simple model for measuring force-feedback during needle penetration of soft tissues and is a good starting point for future studies of the penetration resistance properties of human tissues. PMID:11522313

Frick, T B; Marucci, D D; Cartmill, J A; Martin, C J; Walsh, W R

2001-10-01

82

Microstructural evolution during tensile deformation of polypropylenes  

Energy Technology Data Exchange (ETDEWEB)

Tensile deformation processes occurring at varying strain rates in high and low crystallinity polypropylenes and ethylene-propylene di-block copolymers have been investigated by scanning electron microscopy. This is examined for both long and short chain polymeric materials. The deformation processes in different polymeric materials show striking dissimilarities in spite of the common propylene matrix. Additionally, the deformation behavior of long and their respective short chain polymers was different. Deformation mechanisms include crazing/tearing, wedging, ductile ploughing, fibrillation, and brittle fracture. The different modes of deformation are depicted in the form of strain rate-strain diagrams. At a constant strain rate, the strain to fracture follows the sequence: high crystallinity polypropylenespolypropylenes

Dasari, A.; Rohrmann, J.; Misra, R.D.K

2003-06-25

83

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)

84

Microstructural evolution during tensile deformation of polypropylenes  

International Nuclear Information System (INIS)

Tensile deformation processes occurring at varying strain rates in high and low crystallinity polypropylenes and ethylene-propylene di-block copolymers have been investigated by scanning electron microscopy. This is examined for both long and short chain polymeric materials. The deformation processes in different polymeric materials show striking dissimilarities in spite of the common propylene matrix. Additionally, the deformation behavior of long and their respective short chain polymers was different. Deformation mechanisms include crazing/tearing, wedging, ductile ploughing, fibrillation, and brittle fracture. The different modes of deformation are depicted in the form of strain rate-strain diagrams. At a constant strain rate, the strain to fracture follows the sequence: high crystallinity polypropylenes< low crystallinity polypropylenes< ethylene-propylene di-block copolymers, indicative of the trend in resistance to plastic deformation

85

Arthroscopic suture fixation of tibial eminence fractures.  

Science.gov (United States)

Tibial eminence avulsion fractures are relatively rare injuries, most frequently occurring in skeletally immature patients. Screws or suture fixation can be used, with each offering different potential advantages. The purpose of this retrospective study was to evaluate the clinical outcomes of a suture fixation technique for displaced tibial eminence avulsion fractures using the Rotator Cuff Guide (RCG; Acufex Microsurgical, Mansfield, Massachusetts). In a 12-year period from 1998 to 2010, a total of 17 tibial avulsion fractures were treated using the RCG for suture fixation. Outcomes evaluated included pain at final assessment and findings from Lachman, drawer, pivot shift, flexion, extension, and varus/valgus stress tests. Demographic data, fracture type, mechanism of injury, and postoperative activity were obtained for 17 patients (16 males and 1 female) who underwent surgery during the study period. Average patient age was 16.8 years (range, 13-37 years). Average follow-up was 25 months (range, 2 months to 13 years). Postoperatively, all fractures in all patients were radiographically healed, and all patients had stable Lachman and negative pivot shift tests. Two patients had 3° of extension loss, and 1 patient lost greater than 10° of knee flexion. The length of follow-up was broad. Further limitations include a small sample size and suture versus T-Fix (Acufex Microsurgical, Mansfield, Massachusetts) fixation methods. This technique offers a simplified, reliable method of suture fixation that provides few long-term complications and predictable results. Patients can expect to return to preinjury levels of activity, with the majority of patients achieving full range of motion. PMID:24200444

Kluemper, Chase T; Snyder, Garret M; Coats, Aaron C; Johnson, Darren L; Mair, Scott D

2013-11-01

86

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

87

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)

88

Effect of ?-irradiation on commercial polypropylene based mono and multi-layered retortable food packaging materials  

International Nuclear Information System (INIS)

Irradiation processing of food in the prepackaged form may affect chemical and physical properties of the plastic packaging materials. The effect of ?-irradiation doses (2.5-10.0 kGy) on polypropylene (PP)-based retortable food packaging materials, were investigated using Fourier transform infrared (FTIR) spectroscopic analysis, which revealed the changes happening to these materials after irradiation. The mechanical properties decreased with irradiation while oxygen transmission rate (OTR) was not affected significantly. Colour measurement indicated that Nylon 6 containing multilayer films became yellowish after irradiation. Thermal characterization revealed the changes in percentage crystallinity

89

Skin tension related to tension reduction sutures.  

Science.gov (United States)

The aim of this study was to compare the skin tension of several fascial/subcutaneous tensile reduction sutures. Six upper limbs and 8 lower limbs of 4 fresh cadavers were used. At the deltoid area (10 cm below the palpable acromion) and lateral thigh (midpoint from the palpable greater trochanter to the lateral border of the patella), and within a 3 × 6-cm fusiform area of skin, subcutaneous tissue defects were created. At the midpoint of the defect, a no. 5 silk suture was passed through the dermis at a 5-mm margin of the defect, and the defect was approximated. The initial tension to approximate the margins was measured using a tensiometer.The tension needed to approximate skin without any tension reduction suture (S) was 6.5 ± 4.6 N (Newton). The tensions needed to approximate superficial fascia (SF) and deep fascia (DF) were 7.8 ± 3.4 N and 10.3 ± 5.1 N, respectively. The tension needed to approximate the skin after approximating the SF was 4.1 ± 3.4 N. The tension needed to approximate the skin after approximating the DF was 4.9 ± 4.0 N. The tension reduction effect of approximating the SF was 38.8 ± 16.4% (2.4 ± 1.5 N, P = 0.000 [ANOVA, Scheffé]). The tension reduction effect of approximating the DF was 25.2% ± 21.9% (1.5 ± 1.4 N, P = 0.001 [ANOVA, Scheffé]). The reason for this is thought to be that the SF is located closely to the skin unlike the DF. The results of this study might be a basis for tension reduction sutures. PMID:25569413

Hwang, Kun; Kim, Han Joon; Kim, Kyung Yong; Han, Seung Ho; Hwang, Se Jin

2015-01-01

90

Sutural simplification in Physodoceratinae (Aspidoceratidae, Ammonitina  

Directory of Open Access Journals (Sweden)

Full Text Available The estructural analysis of the shell septum interrelationship in sorne Jurassic ammonites allows us to conclude that sutural simplifications occurred throughout the phylogeny, were originated by alterations in the external morphology of the shell. In the case of Physodoceratinae the simplification observed in the morphology of the septal suture may have a double origin. First, an increase in the size of periumbilical tubercles may determine a shallowing of sutural elements and a shortening of saddle and lobe frilling. In other cases, shallowing is determined by a decrease in the whorl expansion rate, an apparent shortening of secondary branching not being observed.El análisis estructural de la interrelación concha-septo en algunos ammonites del Jurásico superior lleva a concluir que las simplificaciones suturales aparecidas a lo largo de la filogenia fueron originadas por alteraciones ocurridas en la morfología externa de la concha. En el caso concreto de la subfamilia Physodoceratinae, la simplificación observada en la morfología de la sutura puede tener un doble origen. En primer lugar, un incremento en el tamaño de los tubérculos periumbilicales puede determinar una pérdida de profundidad de los elementos de la sutura. siempre acompañada de una disminución en las indentaciones (frilling de sillas y lóbulos. En otros casos el acortamiento en profundidad está determinado por una disminución de la tasa de expansión de la espira, sin que se observe un acortamiento aparente de las ramificaciones secundarias.

Checa, A.

1987-08-01

91

Automatic Detection of Wild-type Mouse Cranial Sutures  

DEFF Research Database (Denmark)

In the study of craniofacial malformations, the cranial sutures are often of interest. The premature fusion of sutures occurring in e.g. Crouzon and Apert syndrome can lead to asymmetric head shape, enlarged intracranial pressure and blindness. In large population studies of such syndromes, automatic detection of the cranial sutures becomes important. We have previously built a craniofacial, wild-type mouse atlas from a set of 10 Micro CT scans using a B-spline-based nonrigid registration method by Rueckert et al. Subsequently, all volumes were registered nonrigidly to the atlas. Using these transformations, any annotation on the atlas can automatically be transformed back to all cases. For this study, two rounds of tracing seven of the cranial sutures, were performed on the atlas by one observer. The average of the two rounds was automatically propagated to all the cases. For validation, the observer traced the sutures on each of the mouse volumes as well. The observer outperforms the automatic approach by approximately 0.1 mm. All mice have similar errors while the suture error plots reveal that suture 1 and 2 are cumbersome, both for the observer and the automatic approach. These sutures can be hard to detect with the eye. We still believe that overall, the errors are not considerable and by qualitatively estimating the accuracy, the automatic sutures are very close to the observer sutures. Our plan is to improve the results by local feature detection methods.

Ólafsdóttir, Hildur; Darvann, Tron Andre

92

The use of imbricated sutures in radioactive plaque brachytherapy surgery  

Directory of Open Access Journals (Sweden)

Full Text Available Kaan Gündüz1, Jose S Pulido1, Peter D Yeakel2, Michael King3, Kelly L Classic1, Keith M Furutani21Department of Ophthalmology, 2Department of Radiation Oncology, 3Section of Media Support Services, Mayo Clinic, Rochester, MN, USAAbstract: This paper describes a new technique to suture the radioactive plaque to sclera. The radioactive plaque is conventionally sutured to the sclera using 5/0 nylon sutures. The imbricated suture technique involves using a 1/0 silk or 2/0 mersilene suture imbricated with the 5/0 nylon suture when the nylon suture is tied and cut. The imbricated suture technique allows easy identification of the plaque at removal and provides a surface that separates the 5/0 nylon from the surface of the eyelet platform, making suture cutting easier and safer. The radiation exposure times ranged from 9.1 minutes to 14 minutes (mean: 10.8 minutes during plaque insertion and from 2.8 to 3.3 minutes (mean: 3.0 minutes during plaque removal with the imbricated suture technique. This technique may decrease radiation exposure time and may prevent inadvertent scleral damage.Keywords: plaque radiotherapy, Iodine-125, Ruthenium-106, Collaborative Ocular Melanoma Study, choroidal melanoma, ciliary body melanoma, retinoblastoma, plaque placement, plaque removal, radiation exposure

Kaan Gündüz

2010-03-01

93

Cranial suture biology of the Aleutian Island inhabitants.  

Science.gov (United States)

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

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

2011-04-01

94

Use of barbed suture in robot-assisted mitral valvuloplasty.  

Science.gov (United States)

Robot-assisted annuloplasty using a mitral band has a major issue: suturing is time consuming because knot tying is performed mechanically under endoscopic view. We suture the mitral band to the native valve by running sutures using the V-Loc barbed suture nonabsorbable wound closure device (Covidien, Mansfield, MA) with 3-0 monofilament. This technique allows rapid suturing of the band to the valve. Although conventional interrupted sutures leave multiple knots protruding on the band, using the V-Loc eliminates the need to tie surgical knots and leaves a clean surface, which may potentially reduce the risk of thrombogenesis. This method is highly useful for robotic mitral annuloplasty. PMID:25555967

Watanabe, Go; Ishikawa, Norihiko

2015-01-01

95

A comparison of different suture techniques for microvascular anastomosis.  

Science.gov (United States)

Of the various techniques known, simple interrupted sutures remain the gold standard in the microanastomosis of vessels. Tying many knots, however, is time consuming. This may be of more significance with tissue such as the jejunum, which is significantly effected by ischemia time, or when several vessels are to be anastomosed. In this study, 60 femoral arteries of rabbits were divided into three equal groups. The arteries were then divided and repaired using simple interrupted, simple continuous, and continuous locked sutures. Application of the Bonferroni t-test revealed that both groups of arteries repaired using continuous sutures exhibited a statistically significant (p < 0.02) reduction in anastomosis time (50%) compared with interrupted suture techniques. However, there also was a 45% incidence of reduction in flow (9 of 21 anastomoses) when the simple running suture technique was utilized, giving the running locked suture unquestionable superiority. PMID:7944193

Schlechter, B; Guyuron, B

1994-07-01

96

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.)

97

The frontosphenoidal suture: fetal development and phenotype of its synostosis  

Energy Technology Data Exchange (ETDEWEB)

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.)

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

98

The Effect of Anchoring Sutures on Medicinal Leech Mortality  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Objective: The implementation of leech therapy for surgical flaps is not always logistically easy or comfortable for patients or healthcare providers. We examine different methods of placing sutures in the medicinal leech, Hirudo medicinalis, to make the implementation of leech therapy easier. Methods: Sixteen leeches were randomly divided into 3 groups: a control group, a deep anchoring suture group, and a superficial anchoring suture group. The leeches were observed to determine if either o...

Davila, Victor J.; Hoppe, Ian C.; Landi, Rocco; Ciminello, Frank S.

2009-01-01

99

The use of imbricated sutures in radioactive plaque brachytherapy surgery  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Kaan Gündüz1, Jose S Pulido1, Peter D Yeakel2, Michael King3, Kelly L Classic1, Keith M Furutani21Department of Ophthalmology, 2Department of Radiation Oncology, 3Section of Media Support Services, Mayo Clinic, Rochester, MN, USAAbstract: This paper describes a new technique to suture the radioactive plaque to sclera. The radioactive plaque is conventionally sutured to the sclera using 5/0 nylon sutures. The imbricated suture technique involves using a 1/0 silk or 2/0 mersil...

Kaan Gündüz; Pulido, Jose S.; Yeakel, Peter D.; et al.

2010-01-01

100

11-0 mersilene as running suture for penetrating keratoplasty.  

Science.gov (United States)

We evaluated astigmatic results and complications of the combined suturing technique in penetrating keratoplasty by using 11-0 Mersilene as a running suture. Twenty-seven grafts were studied for a follow-up that ranged between ten and 46 months (mean, 27.2 months). During the study, complications included three graft failures, one instance of inadvertent breakage of the running suture, one instance of one suture bite cutting through the recipient cornea, and suture microabscesses in two eyes. Keratometric astigmatism was 2.5 +/- 2.1 diopters at six months, was 2.4 +/- 2.3 diopters at 12 months, and was 2.5 +/- 2.0 diopters at 24 months. Our data indicate that 11-0 Mersilene is suitable for the running suture in corneal transplants in the combined technique. Spontaneous suture dissolution did not occur throughout the follow-up period. The use of a less biodegradable suture enables the maintenance of low levels of astigmatism for longer periods when compared with a previous study that used 11-0 nylon suture. PMID:1463036

Frueh, B E; Brown, S I; Feldman, S T

1992-12-15

 
 
 
 
101

Dynamic indentation on layered polypropylene foams  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Foams, and particularly the polypropylene foam, are more and more often used in the area of injury protection and passive safety for its energy absorption capacity. This multi-scale material is constituted of mesoscopic beads with a large variability of the material properties. First, to study the effects of these mesoscopic heterogeneities on both the macroscopic and the local behaviors, numerical simulations on virtual volumes of foam under dynamic loading have been performed. The influence...

Viot P.; Maheo L.

2012-01-01

102

EVALUATION OF COMPOSITE POLYPROPYLENE FIBRE REINFORCED CONCRETE  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Improvements in fly ash based concrete strength in compression and flexural direction are the main objectives of this study. The compressive and flexure strength of concrete for various mixtureproportions of concrete containing the inclusions of different percentage of polypropylene fibers from 0% to 0.3% and fly ash replacement levels at 25% , 50% of fly ash were investigated. The experimental test results showed that PP fibers possess increased extensibility and tensile strength, both at fi...

Sounthararajan, V. M.; Anshul Jain; Abhishek Kumar Singh; Thirumurugan, S.; Sivakumar, Dr A.

2013-01-01

103

EVALUATION OF COMPOSITE POLYPROPYLENE FIBRE REINFORCED CONCRETE  

Directory of Open Access Journals (Sweden)

Full Text Available Improvements in fly ash based concrete strength in compression and flexural direction are the main objectives of this study. The compressive and flexure strength of concrete for various mixtureproportions of concrete containing the inclusions of different percentage of polypropylene fibers from 0% to 0.3% and fly ash replacement levels at 25% , 50% of fly ash were investigated. The experimental test results showed that PP fibers possess increased extensibility and tensile strength, both at first crack and at ultimate, particular under flexural loading; and the fibers were able to hold the matrix together even after extensive cracking. The net result of all these is to impart to the fiber composite pronounced post – cracking ductility which is absence of ordinary concrete. To provide a basis for comparison, reference concrete specimens were cast without polypropylene fiber. The experimental test result showed that the addition of polypropylene fibers at 0.1% volume fraction (Vf showed a consistent improvement in the concrete strength of 44.50 MPa and 55.50 MPa at 7 and 28 days respectively.

V.M. Sounthararajan

2013-04-01

104

High strain rate behaviour of polypropylene microfoams  

Directory of Open Access Journals (Sweden)

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.

Martínez A.B.

2012-08-01

105

Techniques and applications of adjustable sutures.  

Science.gov (United States)

The 'rediscovery' of adjustable sutures some 10 years ago has given the ophthalmic surgeon much more confidence in his ability to correct strabismus. Three methods of use are described: during surgery under general anaesthesia with adjustment during the operation using the 'springback' test to centralise the eye; during surgery under general anaesthesia and subsequent adjustment under local anaesthesia using the patient's subjective responses to obtain optimal positioning; and performance of the operation and adjustment under topical local anaesthesia in one procedure. Full details are given of each technique and the indications for their application to particular problems are discussed. PMID:3297111

Fells, P

1987-02-01

106

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2013-10-01

107

Are intracostal sutures better than pericostal sutures for closing a thoracotomy?  

Science.gov (United States)

A best evidence topic was written according to a structured protocol. The question addressed was to identify which thoracotomy closure method lends itself to the least postoperative pain. Altogether 109 papers were found using the reported search; of which, seven represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that the closure by intracostal sutures with intercostal nerve sparing offers a superior postoperative pain profile for thoracotomy patients when compared with conventional techniques. Up to 1-year follow-up has shown that this technique (avoiding strangulation of the intercostal nerve) leads to lower postoperative pain and analgesic use, better ambulation and a quicker return to daily activities. Three papers (including two randomized trials) found intracostal sutures with intercostal nerve sparing techniques to be superior to conventional methods such as pericostal suture closure. Rib approximation with intercostal nerve sparing was found to be superior to rib approximation without nerve sparing in one study. Two studies associated with the creation of an intercostal muscle flap prior to the insertion of a rib retractor to be associated with significantly reduced postoperative pain. One study described a novel 'edge-closure' technique, comparable to the closure with intracostal sutures without drilling, to be superior to conventional closure with pericostal sutures. Postoperative pain is a significant issue faced by thoracic surgeons both in-hospital and in the longer term where patients may complain of chronic thoracotomy pain. We would therefore recommend that some form of intercostal nerve protection be implemented during thoracotomy opening and closure. PMID:22431654

Visagan, Ravindran; McCormack, David J; Shipolini, Alex R; Jarral, Omar A

2012-06-01

108

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)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish 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.

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

109

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

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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.

F Maldonado

2006-01-01

110

Weld line morphology of injection molded polypropylene  

Science.gov (United States)

One of the main goals of this research was to develop an understanding of the specific cause(s) of mechanical weakness at weld lines in injection molded plastic parts. In this study, a variety of techniques have been used to evaluate polypropylene weld lines: optical microscopy, electron microscopy, x-ray photoelectron microscopy, Fourier transform infrared spectroscopy and mechanical property measurements. Optical microscopy results showed that the weld line penetrates about 10 microns into the sample, and that the crystalline morphology near the weld line was very different than in the polymer further removed. Transmission electron microscopy was used to determine that the material at the weld line was of slightly different density and stained differently than the rest of the polypropylene material. X-ray photoelectron spectroscopy (XPS) determined that the material at the flow front was enriched in elemental sulfur and oxygen, which helped identify it as an antioxidant additive. Finally, FTIR was used to confirm that the flow front tip was enriched in the antioxidant material by comparing spectra of the neat antioxidant. The data cumulatively demonstrate that a low concentration (additive was accumulating at the flow front surface during mold filling, and was subsequently trapped at the weld line as it was formed. This additive accumulation is responsible in a large part for the weakness observed at the weld line in the polypropylene system studied. Other low concentration additives were also found to accumulate at polypropylene weld lines, also making the interface weak. Even an incompatible, higher surface free energy polymer, polystyrene, when added at low concentration to polypropylene, was found to accumulate at the weld line. Therefore, surface free energy was found not to play a role in these accumulations. Homogeneous elongation was found not to reproduce the enrichments observed. The mechanism by which low concentration additives accumulate at flow fronts is speculated to involve incompatible droplets experiencing a stress gradient due to the elongation gradient at the flow front during fountain flow which "pushes" them out toward the free surface. In addition, large concentrations of the heat stabilizer additive was also observed on the injection molded part surface, probably deposited there by fountain flow of the flow front. This observation could have practical implications for using low concentration additives to achieve surface modification of injection molded parts. Attempts were made to modify part surfaces to improve conductivity and part release from the mold. Unfortunately, the base polypropylene polymer used in these experiments contained low level heat stabilizer additives which masked any surface accumulation measurements of other added materials using XPS. In one instance, a mixture of polypropylene with a low concentration of low molecular weight polystyrene, the intended surface modifier was observed by TEM below a thin layer that was determined by XPS to be heat stabilizer. Obviously, a more controlled study of the surface deposition is necessary before it can be exploited.

Mielewski, Deborah Frances

111

Autoadjustable sutures and modified seldinger technique applied to laparoscopic jejunostomy.  

Science.gov (United States)

This is a simple technique to be applied to those patients requiring an alternative feeding method. This technique has been successfully applied to 25 patients suffering from esophageal carcinoma. The procedure involves laparoscopic approach, suture of the selected intestinal loop to the abdominal wall and jejunostomy using Seldinger technique and autoadjustable sutures. No morbidity or mortality was reported. PMID:25318452

Pili, Diego; Ciotola, Franco; Riganti, Juan Martín; Badaloni, Adolfo; Nieponice, Alejandro

2015-02-01

112

Arthroscopic hip labral repair: the iberian suture technique.  

Science.gov (United States)

Arthroscopic hip labral repair has beneficial short-term outcomes; however, debate exists regarding ideal surgical labral repair technique. This technical note presents an arthroscopic repair technique that uses intrasubstance labral suture passage to restore the chondrolabral interface. This "Iberian suture technique" allows for an anatomic repair while posing minimal risk of damage to the labral and chondral tissues. PMID:25126502

Stubbs, Allston J; Andersen, Jason S; Mannava, Sandeep; Wooster, Benjamin M; Howse, Elizabeth A; Winter, S Bradley

2014-06-01

113

Granuloma formation secondary to Achilles tendon repair with nonabsorbable suture  

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•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.

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

2014-01-01

114

STUDY ON METOPIC SUTURES IN SOUTH INDIAN SKULLS  

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Full Text Available The midline suture between two halves of the developing frontal bone usually fuses by infancy or early childhood. In some cases it may persist in complete or incomplete metopic sutures with variable morphology.  The incidence and morphological pattern of these sutures were being studied using 120 skulls from the Department of Anatomy, Yenepoya Medical College among which 4 skulls (3.33% showed complete metopism, 98 skulls (81.66% showed presence of incomplete metopic suture whereas 18 skulls (15% showed total absence of metopic suture. Of the skulls that showed incomplete metopic sutures, 96 (97.95% were on the anterior 1/3 starting from nasion extending over glabella, 2 (2.04% were on the middle 1/3. No suture could be found on the posterior 1/3.The morphological pattern was studied on the sutures present on anterior 1/3 of the skull. Among these, 26 (26.53% were linear, 13 (13.26% were double linear, 13 (13.26% were V shaped, 12 (12.24% were U shaped, 7 (7.14% were H shaped, 5 (5.1% were Y shaped. 2 (2.04% showed inverted-U pattern whereas 18 (18.36% showed side to side excursion patterns. The data obtained in this study will be useful in the field of Anatomy, Forensic medicine, radio diagnosis and neurosurgery.

Rani Nallathamby*, Ramakrishna Avadhani Sivarama CH, Boban Babu and Meera Jacob

2013-07-01

115

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

116

Effect of Braiding and Hot Stretching Conditions on Sutures Performances  

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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.

Faten Debbabi

2011-01-01

117

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

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Full Text Available 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 release rate (GIC, respectively, over virgin PP. On the other hand, 3 wt. % nanoclay PP composites showed superior crack containment properties. These structural changes of composite specimens were examined using Transmission Electron Microscopy (TEM and X-ray diffraction (XRD methods. It showed that exfoli-ated nanocomposite structures were formed up to 3 wt. % nanoclay, whereas, intercalated nanocomposite structures formed above 3 wt. % nanoclay in the PP matrix. Furthermore, the woven fibre reinforced PP composites demonstrated superior crack resistant properties than that of clay filled nanocomposites and chopped fibre PP composites. However, KIC and GIC values for woven fibre composites were lesser than that of chopped fibre composites. Moreover, KIC and GIC values for both nanoclay filled PP composites and woven fibre composites are comparable even though the clay filled PP demonstrated catastrophic failure. Also, the crack propagation rate of PP-nanoclay composites is comparable to that of chopped fibre composites.

A. Ramsaroop

2010-12-01

118

Structure development in melt processing isotactic polypropylene, polypropylene blends/compounds and dynamically vulcanized polyolefin TPEs  

Science.gov (United States)

The influence of various fillers, nucleating agents and ethylene propylene diene terpolymer (EPDM) additive on crystalline modification (alpha-, beta- and smectic forms) and crystalline orientation of polypropylene in die extrudates, melt spun filaments, thick rods, blow molded bottles and injection molded parts of isotactic polypropylene (PP), its blends/compounds and dynamically vulcanized polypropylene thermoplastic elastomers (TPEs) were experimentally studied under a range of cooling and processing conditions. The phenomena of crystallization, polymorphism and orientation in processing of both thin and thick samples (filaments, rods, bottles and injection molded parts) were simulated through transport laws incorporating polymer crystallization kinetics. Continuous cooling transformation (CCT) curves for the various material systems investigated were developed under quiescent and uniaxial stress conditions. We applied experimental data on polymorphism of thin sections to predict crystalline structure variation in thick parts. The predictions were consistent with experiments. For filaments, the polypropylene crystalline orientation-spinline stress relationship is generally similar for the neat PP, blends/compounds and TPEs. However, the blends and TPEs have much lower birefringence apparently due to a lack of orientation in the rubber phase. It was shown that the polypropylene contribution to the birefringence for the neat PP and its blends is the same at the same spinline stress. For bottles, the inflation pressures used have little effect on orientation of either polypropylene crystals or disc-shaped talc filler. The talc discs are highly oriented parallel to the bottle surface. For the bottles without talc, the orientation of polypropylene crystallographic axes are low. The polypropylene crystallographic b-axes in the talc filled bottles are more highly oriented. For injection molded parts, it was found that a low orientation layer exists between the part surface and an intermediate highly oriented layer in the parts of neat PP and its blends/compounds. The thickness of this layer increases as the injection pressure decreases. This layer was not formed in the TPE parts. This would seem to be associated with the TPEs exhibiting a yield stress in shear flow and not exhibiting fountain flow in mold filling. For all parts studied, the orientation characteristics of polypropylene crystallographic axes in the highly oriented layer are similar from sample to sample. The strong orientation of the c-axis parallel to the machine direction and the b-axis perpendicular to the machine direction are observed in the highly oriented layer. The talc discs in both the highly oriented layer and the intermediate position are highly oriented parallel to the part face due to melt flow. At intermediate position in the talc-filled parts, the polypropylene crystallographic (040) planes prefer to align themselves parallel to the part surface but are not so well oriented when the talc is absent.

Yu, Yishan

119

A combination of subcuticular suture and sterile Micropore tape compared with conventional interrupted sutures for skin closure. A controlled trial.  

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We have conducted a controlled trial to compare skin closure using conventional interrupted sutures with a combination of subcuticular suture and sterile Micropore tape in 169 patients undergoing appendicectomy, inguinal herniorrhaphy, or saphenofemoral ligation. We have found that the combination technique consistently gives a better cosmetic result and that the tape acts well as a dressing, is convenient, and is well tolerated by patients.

Taube, M.; Porter, R. J.; Lord, P. H.

1983-01-01

120

Modification of polypropylene fibres by preirradiation technique  

International Nuclear Information System (INIS)

Grafting of polypropylene fibres (POP) prepared by preirradiation techniques is discussed. A hydrophility change in irradiated and modified samples was studied. Irradiation was performed in a chamber type RCH-gamma-30 radiation equipment containing sup(60)Co. In the radiation modified samples of POP fibres prepared by preirradiation technique the humidity adsorption increased from 0.1% to 0.56% using a radiation dose of 24.5 kGy. The sorption properties of the samples were studied on McBeen balances with regard to temperature and water-vapour pressure. (author)

 
 
 
 
121

Usefulness of continuous suture using short-thread double-armed micro-suture for cerebral vascular anastomosis  

Science.gov (United States)

Background: When microvascular anastomosis is performed in a deep, narrow operating field, securing space to throw knots is difficult. To simplify the procedure and avoid obstruction of the anastomosis, we use a continuous suturing with short-thread double-armed micro-suture. Methods: Sixty-four patients (38 cerebral revasculazation, 16 moyamoya disease, and 10 aneurysm surgery) undergoing microvaucular anastomosis were included. During anastomosis, a continuous suture was placed with short-thread double-armed micro-suture. Results: During 64 microanastomosis procedures, 64 consecutive continuous sutures were performed with 1-year follow up. All patients showed patency of anastomosis with long-term follow up. Conclusions: This technique is especially useful for anastomosis in a deep, narrow surgical field, such as in superior cerebellar artery anastomosis. PMID:25396075

Haga, Sei; Nagata, Shinji

2014-01-01

122

Suture-related pseudoinfection after total hip arthroplasty.  

Science.gov (United States)

Absorbable sutures are widely used for wound closure after total hip replacement. Here we present two cases of suture-related foreign-body reaction that perfectly mimicked a periprosthetic joint infection, with sterile abscess formation and physical and laboratory signs of inflammation acutely presenting 7-8 weeks after surgery, at the time of suture absorption. Both recurred with analogous timing after irrigation and debridement, likely due to re-using the same suture material. Multiple negative microbiological samples and positive histological samples showing a foreign-body reaction are the fundamental steps towards the diagnosis of a suture-related pseudoinfection (SRPI). Only three other cases have been reported to date, but the recurrence, together with the self-healing course after relapse, represents a completely novel feature and possibly the strongest demonstration of the supposed aetiopathogenesis. The knowledge of this possible complication leads to some clinical implications: all potential periprosthetic joint infections should routinely undergo not only microbiological but also histological sampling; caution should be used when recommending prosthesis exchange for potential infections occurring in the time range of suture absorption; lastly, if SRPI is suspected, a suture with low propensity to induce foreign-body reactions should be chosen after irrigation and debridement and the volume of absorbable material left in the wound should be as small as possible. PMID:24916148

Pierannunzii, Luca; Fossali, Andrea; De Lucia, Orazio; Guarino, Arturo

2014-06-11

123

[Suture technics for the abdominal wall after midline laparotomy].  

Science.gov (United States)

During the last 10 years 268 laparotomies by a midline incision were performed. A high incidence of seromas, fistulas caused by suturing material and wound ruptures were observed. After finding only a small number of publications in the veterinary medicine about wound healing disturbances an analysis of the human medical literature was done. This induced the change of our surgical procedure and suturing technique: The midline incision and surgical management during the laparotomies in 14 horses suffering from colic were performed by a minimized trauma. The abdominal wall was closed layer by layer in the following manner: peritoneum by a running suture of catgut metric 5, linea alba by Sultan single sutures of polyglycolic acid material metric 5 (12 cases) or of polydioxanone metric 4 (2 cases), subcutaneous layer by a running suture of polyglycolic acid material metric 4, skin by single sutures of monofilamentous synthetic material metric 2. Thus, no complications in wound healing were observed in these 14 horses. Therefore, we recommend to prove the described surgical and suturing procedure by a larger number of horses undergoing a laparotomy by a midline incision. PMID:3907012

Becker, M

1985-01-01

124

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

125

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 anompared with commercial silk sutures in an in vivo comparative study.

126

Ectocranial suture fusion in primates: pattern and phylogeny.  

Science.gov (United States)

Patterns of ectocranial suture fusion among Primates are subject to species-specific variation. In this study, we used Guttman Scaling to compare modal progression of ectocranial suture fusion among Hominidae (Homo, Pan, Gorilla, and Pongo), Hylobates, and Cercopithecidae (Macaca and Papio) groups. Our hypothesis is that suture fusion patterns should reflect their evolutionary relationship. For the lateral-anterior suture sites there appear to be three major patterns of fusion, one shared by Homo-Pan-Gorilla, anterior to posterior; one shared by Pongo and Hylobates, superior to inferior; and one shared by Cercopithecidae, posterior to anterior. For the vault suture pattern, the Hominidae groups reflect the known phylogeny. The data for Hylobates and Cercopithecidae groups is less clear. The vault suture site termination pattern of Papio is similar to that reported for Gorilla and Pongo. Thus, it may be that some suture sites are under larger genetic influence for patterns of fusion, while others are influenced by environmental/biomechanic influences. PMID:24142900

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

2014-03-01

127

Iatrogenic Ulnar Nerve Injury post Laceration Suturing – An Unusual Presentation  

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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 scre...

Murali Mothilal; Mothilal S N; Ravichandran S; Jamal Mohammad

2013-01-01

128

Elution behavior of polyethylene and polypropylene standards on carbon sorbents.  

Science.gov (United States)

The elution behavior of linear polyethylene and isotactic, atactic and syndiotactic polypropylene was tested using three different carbon column packings: porous graphite (Hypercarb), porous zirconium oxide covered with carbon (ZirChrom-CARB), and activated carbon TA 95. Several polar solvents with boiling points above 150°C were selected as mobile phases: 2-ethyl-1-hexanol, n-decanol, cyclohexylacetate, hexylacetate, cyclohexanone, ethylene glycol monobutyl ether and one non-polar solvent, n-decane. Polyethylene standards were completely or partially adsorbed in all tested sorbent/solvent systems. Polypropylene standards were partially adsorbed on Hypercarb and carbon TA95, but did not adsorb on ZirChrom-CARB. ZirChrom-CARB retained polyethylene pronouncedly when 2-ethyl-1-hexanol, cyclohexylacetate or hexylacetate were used as mobile phases at temperature 150 or 160°C, while all three basic stereoisomers of polypropylene eluted in size exclusion mode in these sorbent/solvent pairs. This is very different from the system Hypercarb/1-decanol, which separated polypropylene according to its tacticity. The opposite elution behavior of polyethylene and polypropylene in system ZirChrom-CARB/2-ethyl-1-hexanol (polypropylene eluted, polyethylene fully adsorbed) enabled to realize separation of blends of polyethylene and polypropylene. Ethylene/1-hexene copolymers were separated according to their chemical composition using system Hypercarb/2-ethyl-1-hexanol/1,2,4-trichlorobenzene. PMID:21035809

Chitta, Rajesh; Macko, Tibor; Brüll, Robert; Kalies, Grid

2010-12-01

129

Study on thermal decomposition of calix[4]arene and its application in thermal stability of polypropylene  

Energy Technology Data Exchange (ETDEWEB)

Thermal decomposition kinetics of calix[4]arene (C4) was investigated using thermogravimetric analysis (TGA) and derivative of TG curve (DTG). TG experiments were carried out under static air atmosphere with nominal heating rates of 1.0, 2.5, 5.0 and 10.0 K/min. Model-fitting methods and model-free methods such as Friedman and Ozawa-Flynn-Wall methods were employed to evaluate the kinetic parameters such as activation energy (E{sub a}), exponential factor (ln A) and reaction order (n). To determine the antioxidant property of C4 the non-isothermal kinetics of polypropylene (PP) with C4 as additive was studied. The FTIR, ESR and {sup 13}C NMR CP-MAS techniques were used to propose the decomposition mechanism of C4 in the presence of PP.

Chennakesavulu, K., E-mail: chennanml@yahoo.com [National Metallurgical Laboratory Madras Centre, CSIR Complex, Taramani, Chennai 600113 (India); Basariya, M. Raviathul; Sreedevi, P.; Bhaskar Raju, G.; Prabhakar, S.; Rao, S. Subba [National Metallurgical Laboratory Madras Centre, CSIR Complex, Taramani, Chennai 600113 (India)

2011-03-10

130

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

131

Electrophysical Properties of Composites Based on Atactic Polypropylene  

Science.gov (United States)

Results of investigations of the dielectric permittivity and dielectric loss tangent are presented for a wide frequency range. Physical and chemical properties of modified atactic polypropylene are investigated and experimental parameters of its adhesion to the steel and concrete surfaces are given. It is demonstrated that atactic polypropylene can be used as an electric insulator and water repellent to protect from corrosion metal structures and concrete products used in power engineering. Modification of atactic polypropylene increases the real component of the dielectric permittivity and decreases the dielectric loss tangent, thereby significantly decreasing its conductive properties. This can be used for electric insulation of energy-intensive units.

Debelova, N. N.; Suslyaev, V. I.; Gorlenko, N. P.; Zhuravlev, V. A.; Zav'yalova, E. N.; Dotsenko, O. A.; Zav'yalov, P. B.; Ul'yanova, O. A.

2014-07-01

132

[Mechanical anastomosis without purse-string suture in esophageal surgery].  

Science.gov (United States)

A new surgical procedure for oesophago-enterostomy using staplers without purse-string suture is described. This technique is possible only using the CEEAP stapler, thanks to its new technical features. PMID:2223480

Liboni, A; Zamboni, P; Occhioni, G; Masia, S; Passerò, G; Trignano, M

1990-03-01

133

Cierre de la pared abdominal: qué técnica y qué sutura se deben usar / Closing the abdominal wall: what technique and type of suture to use  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Introducción: El cierre de la pared abdominal es un procedimiento frecuente en la práctica de los cirujanos generales. El tipo de cierre y el material de sutura en la mayoría de los casos se realizan y escogen en forma empírica. El presente estudio valora la mejor evidencia disponible sobre la técni [...] ca para el cierre de la fascia abdominal y el tipo de sutura. Métodos: Se realizó una búsqueda sistemática de la literatura y se evaluaron los artículos de más alta calidad (revisiones sistemáticas). Los resultados se analizaron particularmente. Resultados: La mejor técnica de sutura de la fascia abdominal es aquella con puntos continuos con material de absorción lenta (polidioxanona) o no absorbible (polipropileno), los cuales tienen índices de hernia incisional menores que las suturas de absorción rápida. Conclusiones: Es recomendable utilizar sutura de material de absorción lenta o no absorbible para el cierre de la pared abdominal. Abstract in english Introduction: Closure of the abdominal wall is a frequently performed procedure in general surgical practice. The type of closure and the suture material are often chosen on empirical bases. The present study evaluates the best evidence available regarding the technique of closure of the abdominal w [...] all and the best suture material to be used. Methods: A systematic literature search was undertaken and the best quality articles (systematic reviews) were analyzed. Results: The best technique appears to be the closure with interrupted sutures of slow absorption (polydioxanone) or non absorbable (polypropylene) material, which exhibit lower recurrence rates that those observed with materials of rapid absorption. Conclusions: It is recommended to utilize interrupted sutures of slow absorption or non absorbable material for closing the abdominal wall.

Carlos, Lehmann; Álvaro, Sanabria; Eduardo, Valdivieso; Gabriel, Gómez.

2007-06-01

134

SUTURE NON-SUTSRE CIRCUMFERENTIAL REPAIR OF CAROTID ARTERY  

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Full Text Available plastic adhesives, normal butyl cyanoacrylate monomer, isobutyl cyanoacrylate monomer and methyl 2 _ cyaooacrylate monomer, have been utilized in a comparative study with 5-{ silk suture in the repair of transected carotid arteries. Follow _ up arteriog ramS indicate isobutyl cyanoacrylate monomer and normal butyl cyanoacrylate monomer as having the most impressive rerults with only tWO thrombosis each. The silk suture had three thromboses and the adhesive methyl 2 _ cyanoacrylate monomer had nine, one of which a delayed

Jafar Nader

1969-01-01

135

Suture Granuloma Mimicking Recurrent Thyroid Carcinoma on Ultrasonography  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Although high resolution ultrasonography (US) is helpful in the differentiation of suture granulomas from recurrent thyroid cancer in most cases, a definite diagnosis cannot always be made. We report a case that mimicked recurrent thyroid cancer on US and 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET), but diagnosis of a suture granuloma was confirmed by a US-guided fine needle aspiration biopsy (FNAB). In order to avoid unnecessary operations, the different...

Chung, Yong Eun; Kim, Eun-kyung; Kim, Min Jung; Yun, Mijin; Hong, Soon Won

2006-01-01

136

Effect of Suture Lines on Lung Adenocarcinoma Cell in vitro  

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Background and objective The interaction of cell and medical biomaterial is one of the significant factors to affect clinical application of medical biomaterial. This research is to investigate three of suture lines how to affect the proliferation and cell cycle of Lung Adenocarcinoma cell A549. Methods Three of suture lines are respectively cultivated with Lung Adenocarcinoma cell A549, after of 72 hours, to detect absorptance of each groups by MTT method in order to reflect the proliferatio...

Ye, Lianhua; Huang, Yunchao; Li, Gaofeng; Jin, Qilin; Duan, Lincan; Xiang, Xudong; Guo, Gang

2009-01-01

137

Utilização do laser de argônio na remoção de sutura corneana Use of argon laser in corneal suture removal  

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Full Text Available OBJETIVO: Descrever a técnica da retirada de sutura em córnea clara, evitando-se o contato da parte externa do fio com o meio intra-ocular e avaliar se esse procedimento evitaria infecções. MÉTODOS: Foi realizado estudo retrospectivo de 1.233 casos de retirada de sutura de mononylon 10.0 em córnea clara, utilizando-se laser de argônio para cortar o fio, no qual se avaliou a incidência de infecções. RESULTADOS: Em 1.071 olhos, um tiro foi suficiente para cortar o ponto. Em 162 olhos, o tiro do laser atingiu a parte epitelial da sutura, sendo necessários disparos extras para cortar a parte intra-estromal e, assim, retirá-la sem que a parte externa do fio passasse pelo interior da córnea. Não ocorreram complicações após a retirada da sutura. CONCLUSÕES: A técnica utilizada mostrou-se eficaz na remoção das suturas e possivelmente apresenta risco menor de infecção, uma vez que a parte do fio sobrejacente ao epitélio não entra em contato com as camadas mais internas da córnea, nem com a câmara anterior, não tendo sido observado nenhum caso de infecção nesta pesquisa.PURPOSE: To describe the technique of clear-cornea suture removal, that avoids the contact of the external part of the thread with the intraocular medium, and to evaluate whether this procedure would prevent infections. METHODS: A retrospective study of 1.233 cases of clear-cornea mononylon 10.0 suture removal, by the use of an argon laser to cut the thread, was performed. Incidence of infection was then assessed. RESULTS: In 1.071 eyes, one shot was enough to cut the stitch. In 162 eyes, the laser shot hit the epithelial part of the suture, making new shots necessary to cut the intrastromal part, and thus to remove it assuring that the outer part of the stitch would not come in to contact with the interior of the cornea. There were no complications after suture removal. CONCLUSIONS: The technique has shown to be effective in suture removal. And, possibly, presents a lower risk for infection, since the external part of the thread does not come in to contact with the innermost parts of the cornea, or with the anterior chamber. No cases of infection have been observed during this research.

Edélcio Vieira

2004-12-01

138

Dynamic indentation on layered polypropylene foams  

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Full Text Available Foams, and particularly the polypropylene foam, are more and more often used in the area of injury protection and passive safety for its energy absorption capacity. This multi-scale material is constituted of mesoscopic beads with a large variability of the material properties. First, to study the effects of these mesoscopic heterogeneities on both the macroscopic and the local behaviors, numerical simulations on virtual volumes of foam under dynamic loading have been performed. The influence of the organized system of heterogeneities has also been studied in the cases of a random distribution and a multi-layered volume. Experimental dynamic compressive tests have been performed on multi-layered volumes of foam and compared with the results of the Finite Element Method. Second, indentation experiments have also been performed using a cylindrical shape indenter.

Viot P.

2012-08-01

139

Electron beam modification of polypropylen fabrics  

International Nuclear Information System (INIS)

In this study, Electron bombardment with the energy of 10-40 Kev and different period of time has been carried out. Electron beam processing of polypropylene (PP) fabrics is found to promote significant changes in physical and chemical properties. The obtained data show that, electron beam processing of PP fabrics allows an adjustable modification of their surface properties. The functional groups on the surface of samples were examined using FTIR spectrometer. Moreover, dyeing properties for treated fabrics has been tested. Relative increase in color strength has been achieved. Morphology of samples was examined by Scanning Electron Microscopy (SEM). The absorption times and contact angle were utilized to analyze the result of the treated samples. This process is promising for the compatibilization of PP fiber and matrix with various compound in blends and production of multilayered composites for versatile applications such as laminates and supported compound. (author)

140

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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 abdom [...] inal, 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. Abstract in english 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 abdom [...] inal 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.

Marcelo Seixo de Brito e, Silva; Renato Miranda de, Melo; Liliana Borges de, Menezes; Sonia Maria, Malmonge; Leandro Guimarães, Franco; Neusa Margarida, Paulo.

2010-08-01

 
 
 
 
141

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  

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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.

Marcelo Seixo de Brito e Silva

2010-08-01

142

Iatrogenic Ulnar Nerve Injury post Laceration Suturing – An Unusual Presentation  

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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

Murali Mothilal

2013-07-01

143

Effect of Suture Lines on Lung Adenocarcinoma Cell in vitro  

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Full Text Available Background and objective The interaction of cell and medical biomaterial is one of the significant factors to affect clinical application of medical biomaterial. This research is to investigate three of suture lines how to affect the proliferation and cell cycle of Lung Adenocarcinoma cell A549. Methods Three of suture lines are respectively cultivated with Lung Adenocarcinoma cell A549, after of 72 hours, to detect absorptance of each groups by MTT method in order to reflect the proliferation of Lung Adenocarcinoma cell A549 and to detect percentage of G1 period cell and S period cell of each of groups by flow cytometry. Results Different of suture lines have effect differently on the proliferation and cell cycle of Lung Adenocarcinoma cell A549 (P < 0.05. The effect of absorbent suture line on the proliferation and cell cycle of Lung Adenocarcinoma cell A549 is strong, the effect of chorda serica chirurgicalis is medium, the effect of slide wire is poor. Different length of each suture line have effect differently on the proliferation and cell cycle of Lung Adenocarcinoma cell A549 (P < 0.05. Conclusion Three of suture line materials have different effect on the proliferation and cell cycle of Lung Adenocarcinoma cell A549, to reflect dose-effect relation.

Lianhua YE

2009-09-01

144

Development of braided drug-loaded nanofiber sutures  

Energy Technology Data Exchange (ETDEWEB)

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.

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

145

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

146

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)

147

Thermal conductivity of polypropylene filled with inorganic particles  

Energy Technology Data Exchange (ETDEWEB)

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.

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

148

Investigation of Mechanical Properties of Rice Straw Fibre Polypropylene Composites  

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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...

K Sudhakar,; Ch. Srinivas

2014-01-01

149

Physicomechanical properties of polypropylene composites filled by modified nano silicates  

International Nuclear Information System (INIS)

This article is devoted to physicomechanical properties of polypropylene composites filled by modified nano silicates. Thus, the electron microscopy, mechanical, dynamical, and rheological study of polypropylene, filled by nano silica gel and silica gel modified by gamma-aminopropyltrimethoxysilane (C6H17O3N) was conducted. It was found that modification of silica gel surface by hydrophobic agent improve the interaction of filler particles with polymer matrix, improve the uniform distribution, prevent the agglomerate formation, increase the elasticity of composite material.

150

Compounds made of aluminium and irradiation grafted polypropylene  

International Nuclear Information System (INIS)

Radiation induced grafting of acrylic acid onto polypropylene surfaces by mutual radiation technique yields products which are especially suitable for making compounds with aluminium. Polypropylene can be used, for instance, as plates or foils, onto which grafting may be performed by a continuous or a discontinuous process. From these grafted plates or foils compounds have been made with aluminium, and their properties have been investigated in various tests. (author)

151

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

152

Radiation resistant modified polypropylene; Polipropylen modyfikowany odporny radiacyjnie  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1997-10-01

153

Environmental and Cost Assessment of a Polypropylene Nanocomposite  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper describes a study on the use of a polypropylene (PP)/layered silicate nanocomposite as packaging film, agricultural film, and automotive panels. The study’s main question was ‘‘Are the environmental impacts and costs throughout the life cycle of nanocomposite products lower than those of products manufactured from conventional materials?’’ The conventional (benchmark) materials studied were pure polypropylene as packaging film, pure polyethylene as agricultural film, and ...

Roes, A. L.; Marsili, E.; Nieuwlaar, E.; Patel, Martin Kumar

2007-01-01

154

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)

155

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

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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.

Stephen H Cummings

2012-07-01

156

Functionalized polypropylenes as efficient dispersing agents for carbon nanotubes in a polypropylene matrix; application to electromagnetic interference (EMI) absorber materials  

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Carbon nanotubes (CNTs) have been dispersed within polypropylene with the purpose to prepare electromagnetic interference (EMI) absorbers. In order to limit the reflectivity of the electromagnetic waves at the interface of the materials while achieving good absorbing properties, the CNTs concentration must be kept low (<3 wt%) which means that a perfect dispersion must be ensured. Since CNTs do not disperse well within apolar polymer matrices such as polypropylene, two compatibilizers bearing...

Thomassin, Jean-michel; Huynen, Isabelle; Je?ro?me, Robert; Detrembleur, Christophe

2010-01-01

157

Effect of Maleated Polypropylene (MAPP) on the Tensile, Impact and Thickness Swelling Properties of Kenaf Core – Polypropylene Composites  

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The study on the kenaf core fiber – polypropylene (PP) composites with treated and non-treated maleated polypropylene (MAPP) was done. Epolene-43 which is commercially MAPP was used to determine MAPP’s effectiveness as a coupling agent for kenaf fiber-composites. The hot pressing system for producing kenaf core-PP composite has been used. The tensile, impact and thickness swelling results of the epolene 43 treated composite samples were better than those of the ...

Mohamad Jani Saad

2011-01-01

158

Midwives conducting perineal repair: The Danish Suture Trial  

DEFF Research Database (Denmark)

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 August 2004, enrolment of patients finished October 2005. Sample size: 400. Inclusion: Healthy primipara sustaining a 2nd degree perineal laceration or an episiotomy following vaginal birth. Perineal repair was carried out by a midwife. Exclusion: Lacerations involving the sphincter ani, post partum haemorrhage >1000 ml, Diabetes, mental disorders. Both suture techniques were 2-layered using a polyglactin910 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 assessed day 1-2 and 10 post partum. Secondary outcomes: patient satisfaction with wound healing, need for secondary repair, superficial pain during intercourse.   Data management: Double entry of all data and intention-to-treat analysis.   Results The follow up rate was 97%. Baseline data were evenly distributed between the two treatment groups. Major difference in pain and healing was observed between spontaneous lacerations and episiotomies. Follow up 6 months post partum will be finished by April 2006.   Conclusion Primary results will be presented on the NFOG Congress in Göteborg, May 2006.

Kindberg, Sara

2007-01-01

159

Study of Insertion Force and Deformation for Suturing with Pre-Curved NiTi Guidewire.  

Science.gov (United States)

This research presents an experimental study evaluating stomach suturing using a pre-curved nickel-titanium (NiTi) guidewire for minimally invasive procedures. Precise path planning is critical for accurate and effective suturing. A position measurement system utilizing a hand-held magnetic sensor was used to measure the shape of a pre-curved guidewire and to determine the radius of curvature before and after suturing. Ex vivo stomach suturing experiments using four different guidewire tip designs varying the radius of curvature and bevel angles were conducted. The changes in radius of curvature and suturing force during suturing were measured. A model was developed to predict the guidewire radius of curvature based on the measured suturing force. Results show that a small bevel angle and a large radius of curvature reduce the suturing force and the combination of small bevel angle and small radius of curvature can maintain the shape of guidewire for accurate suturing. PMID:25480363

Wang, Yancheng; Chen, Roland K; Tai, Bruce L; Xu, Kai; Shih, Albert J

2014-12-01

160

[Behavior of modern suture materials in infected urine].  

Science.gov (United States)

The recently developed absorbable materials demonstrate a constant and reproducible high quality when compared with the resorbable suture materials. However, based on in vitro studies by different authors the use of these materials in infected urine is not recommended. We investigated in vivo in infected urines the stability of the suture materials composed of polyglycolic acid, and compared the results obtained in vitro and in vivo. In a controlled study the stability of the absorbable suture materials polyglycolic acid, polyglactin 910 and polydioxanon 4/0 USP were tested in infected urine in vivo and in vitro. In 21 patients with infected urine the suture materials were placed into the bladder for 7 days. In another experiment these materials were incubated up to 7 days in culture flasks with infected urine. After that the suture materials were examined by densitometry and electrone microscopy. When using the results obtained in vitro in clinical work caution is recommended. However, the in vivo tests show that the stability of the newly developed absorbable materials is not influenced dramatically by the infected urine. PMID:2820103

Osterhage, H R; Kottwitz, J; Heckl, W

1987-07-01

 
 
 
 
161

Anatomic features of metopic suture in adult dry skulls.  

Science.gov (United States)

The metopic suture (MS) lies on the midline of the forehead and extends from the frontal bone to the root of the nose. The aim of the current study was to evaluate morphologic features of the complete and incomplete MSs of skulls in the West Anatolian population and rates of the suture types. One hundred sixty crania of West Anatolian people with unknown ages and sex belonging to the anatomy department laboratory of Dokuz Eylül University Medical School were examined. When the MSs that extend from the nasion to the bregma are complete, this condition was named as metopism. The length of the complete sutures was measured using a flexible millimeter calibrated ruler. If the suture was not present throughout between these 2 landmarks (nasion and bregma), these were considered as the incomplete MSs. The incomplete MSs were classified as linear, V-shaped, and double types. The incidence of the complete and incomplete sutures was 75%. The complete (metopism) and incomplete MSs were found in 7.50% and 67.50% of the skulls, respectively. The most common type was linear (39.40%), followed by double shaped (23.10%) and V shaped (5%). The mean length of the complete MS was 12.30 cm. Because the localization and types of MSs are important during clinical approaches, while evaluating patients with head trauma in the emergency department, these should be considered. PMID:24699103

Aksu, Funda; Cirpan, Sibel; Mas, Nuket Gocmen; Karabekir, Selim; Magden, Abdurrahman Orhan

2014-05-01

162

Recognizing surgeon's actions during suture operations from video sequences  

Science.gov (United States)

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.

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

2014-03-01

163

Magnetic fluids stabilized by polypropylene glycol  

International Nuclear Information System (INIS)

A series of samples of magnetic fluids stabilized with low-molecular weight polypropylene glycol (PPG) of different molecular masses were synthesized. The use of PPG allowed the maximum extension of the carrier fluid range to include ethyl- and butyl-acetate, ethanol, butanol, acetone, carbon tetrachloride, toluene, kerosene and PPG itself. Magnetic and rheological properties of the samples were investigated. Based on the results of investigation it has been concluded that magnetic nanoparticles are covered by a monolayer of surfactant molecules. At low temperatures the propanol-based sample preserves fluidity up to -115 oC. Measurement of critical temperatures of other base fluids showed that alcohols are the best carrier medium. Coagulation stability of the ethanol-based ferrocolloid with respect to water and kerosene was explored. It has been found that kerosene, whose fraction by weight exceeds 22.5%, does not mix with the colloid. This effect can be used to produce magneto-controllable extractors of ethyl alcohol. Under the action of water the colloid coagulates, which allows one to substitute the carrier fluid and to separate the colloid into fractions. - Research highlights: ? PPG stabilizes the magnetic particles in the polar and non-polar media. ? The minimum operating temperature reaches -115 oC. ? Alcohols are the best environment for PPG-stabilized particles. ? PPG magnetic fluids can be used as magnetic extractors of alcohol.as magnetic extractors of alcohol. ? PPG MF can be divided into fractions by partial coagulation with water.

164

OLED-polypropylene bio-CD sensor  

Science.gov (United States)

With the goal of developing microfluidic platforms for sensing applications, flash-free micro patterns were embossed in polypropylene surfaces with ultrasonic heating for a biosensing lab-on-CD application. The embossed features were designed to act as reservoirs, valves, and reaction chambers to allow, in combination with a compact sensing platform, the monitoring of analyte levels using a standard PC-CD player. To generate the compact sensor, as an example, we chose the photoluminescence (PL)-based detection of lactate and glucose using an OLED-based sensing platform. Once embossed, the surface energy of the plastic substrate was chemically modified to make it hydrophilic. Reagents, placed in separate reservoirs, were directed through burst valves towards a reaction chamber via CD rotation. Lactate or glucose were monitored by measuring the effect of the related dissolved oxygen level on the PL decay time of an oxygen-sensitive dye, following analyte oxidation catalyzed by a suitable specific oxidase enzyme. The results demonstrate the potential of integrating OLEDs as excitation sources in PL-based sensors with microfluidic CD-based platforms, including for simultaneous multiple analyses.

Vengasandra, Srikanth; Cai, Yuankun; Grewell, David; Shinar, Joseph; Shinar, Ruth

2008-08-01

165

Grafting of styrene onto polypropylene membranes  

Energy Technology Data Exchange (ETDEWEB)

The grafting of styrene onto polypropylene (PP) by simultaneous radiation was carried out. The effects of absorbed dose and the pos radiation period on the grafting yield were investigated. The experiment comprised PP films with 40{mu}m thickness exposed to gamma ionizing radiation at room temperature and nitrogen atmosphere. The films were immersed in styrene/toluene and then irradiated at total dose of 40, 80 and 100 kGy. After irradiation the samples were evaluated at periods of 0, 7, 14, 21 and 28 days at room temperature in order to observe the behavior of grafting degree. Structural, chemical changes and surface morphologies of the modified PP films were characterized by infrared spectroscopic analysis (FTIR), differential scanning calorimetry analysis (DSC), thermogravimetric analysis (TGA) and the degree of grafting (DOG) was gravimetrically determined. The simultaneous radiation indicated the dependency of the percent graft on the absorbed dose. The DOG values are higher when the film was submitted at 100 kGy dose. The thermal stability shows a decrease in the degradation temperature of the modified samples in comparison with the pure polymer. (author)

Zen, Heloisa A.; Geraldes, Adriana N.; Parra, Duclerc F.; Lugao, Ademar B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], E-mail: helozen@ipen.br

2007-07-01

166

Polypropylene matrix composites reinforced with coconut fibers  

Directory of Open Access Journals (Sweden)

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.

Maria Virginia Gelfuso

2011-09-01

167

Polypropylene matrix composites reinforced with coconut fibers  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

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

2011-09-01

168

Surface modification of polypropylene based particle foams  

Science.gov (United States)

This paper deals with the modification of the surface properties of expanded polypropylene (EPP). EPP is a semi-hard to soft elastic thermoplastic foam. The characteristic surface of EPP shows process-related steam nozzle imprints and gussets. Therefore EPP does not satisfy the quality requirements for visible automotive applications. In order to meet these demands, plastic surfaces are usually enhanced with functional or decorative coatings, e.g. textiles, plastic films or paint. The coating of plastics with low surface energies such as PP often leads to adhesion problems by reason of the missing polar and functional groups. This paper gives an evaluation of activation and pre-treatment methods of EPP, with the aim to identify the most suitable pre-treatment method. For this purpose five typical surface treatment methods - flame treatment, corona, fluorination, atmospheric and low-pressure plasma - were performed on EPP samples. As a comparison criterion the maximum increase in the adhesion force between a polyurethane-based coating and the modified EPP substrate was selected. Moreover the influence of the selected pre-treatment method on the increase in the total surface energy and its polar component was investigated by the drop shape analysis method. The results showed that the contact angle measurement is a suitable method to determine the polar and disperse fractions of the surface tension of EPP. Furthermore, all performed methods increased the adhesion of EPP.

Schreier, P.; Trassl, C.; Altstädt, V.

2014-05-01

169

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 ?m, 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.

170

Study of Maleic Anhydride Grafted Polypropylene Effect on Resin Impregnated Bamboo Fiber Polypropylene Composit  

Directory of Open Access Journals (Sweden)

Full Text Available Previously, Polyvinyl Alcohol (PVA and phenolic resin were used for resin impregnated bamboo fiber reinforced PP composites which was manufactures for resin impregnated bamboo fiber with polypropylene (PP. Resin impregnation method can show improvement on tensile strength of fiber. However, to reduce the contact surface area and low inter-facial shear strength (IFSS between impregnated resin and matrix, using 40% weight fraction of bamboo fiber in PP matrix, PVA impregnated composites with mean flexural and tensile strength 10% higher than untreated composites were produced butphenolic resin impregnated fiber reinforced composition’s mechanical properties were decreased. In this study maleic anhydride grafted polypropylene (MAPP was used to increase interfacial shear strength between resin impregnated fiber and PP. With 10% MAPP, IFSS between resin impregnated fiber and PP increased more than 100% and reinforced composites. MAPP with untreated, phenolic resin and PVA impregnated cases showed similar mechanical properties. Yet in water absorption test, the PVA treatment with bamboo/PP composites increased water absorption ratio. But with 10% MAPP, matrix PP water absorption ratio decreased like phenolic resin impregnated fiber reinforced composites. 10% MAPP with resin impregnated bamboo fiber reinforced PP composites can improve IFSS, mechanical properties of composite and can decrease water absorption PVA resin impregnated bamboo fiber reinforced composites.

Gibeop Nam

2014-11-01

171

Toughening of polypropylene with ?-nucleated thermoplastic vulcanizates based on polypropylene/ethylene–propylene–diene rubber blends  

International Nuclear Information System (INIS)

Highlights: • We designed and prepared ? nucleated thermoplastic vulcanizates. • We adopted the ? 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 ?-nucleating agent (?-NA) were prepared and introduced into isotactic PP matrix as a toughening agent. The effect of ?-nucleated TPVs (?-TPVs) on the toughness and other properties of PP were studied. Differential scanning calorimetry and wide-angle X-ray diffraction results indicated that the ?-crystallinity and the relative content of ?-phase in ?-TPVs samples and the toughened blends increased with the content of ?-NA increasing. The notched impact strength of PP toughened by ?-TPVs, with limited loss in the tensile strength and rigidity, showed an almost linear increase with increasing ?-NA content. Especially when the content of ?-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

172

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

Science.gov (United States)

... 2010-04-01 false Intracardiac patch or pledget made of polypropylene...Prosthetic Devices § 870.3470 Intracardiac patch or pledget made of polypropylene...a) Identification. An intracardiac patch or pledget made of...

2010-04-01

173

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

Science.gov (United States)

...2010-04-01 false Intracardiac patch or pledget made of polypropylene, polyethylene... Intracardiac patch or pledget made of polypropylene, polyethylene...Identification. An intracardiac patch or pledget made of...

2010-04-01

174

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

Energy Technology Data Exchange (ETDEWEB)

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.

Hadal, R.S.; Dasari, A.; Rohrmann, J.; Misra, R.D.K

2004-05-15

175

Co-60 gamma radiation assisted diffusion of iodine in polypropylene  

International Nuclear Information System (INIS)

Thin films of polypropylene having dimensions 50 mm x 15 mm x 350 ?m were immersed in 1 N iodine solution and then irradiated with Co-60 gamma radiation for the periods of 48, 96 and 144 h at the doses varying from 14.4 to 43.2 kGy. The films were also kept immersed in iodine solution for similar periods but without irradiation. Furthermore, the films were also directly-irradiated with Co-60 gamma radiation for similar periods and doses. The radiation-iodinated, plain-iodinated and directly-irradiated samples were characterized by using various techniques such as weight gain EDS, SEM, FTIR, UV-visible spectroscopy, contact angle and XRD. Weight gain, EDS and SEM collectively reveal that gamma irradiation enhances iodine intake in polypropylene. FTIR, EDS and contact angle measurements indicate that presence of iodine during irradiation resists radiation induced carbonylation of polypropylene. FTIR also shows presence of HOI (Hypoiodous acid) species instead of expected C-I bonds. UV-visible analysis unambiguously shows that presence of iodine enhances radiation induced band gap reduction process of polypropylene. XRD indicates that iodine decreases the crystallinity of polypropylene.

176

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Devisme, Samuel; Haudin, Jean-marc; Agassant, Jean-franc?ois; Rauline, Damien; Chopinez, Fabrice

2006-01-01

177

Silicon oxide diffusion barrier coatings on polypropylene  

International Nuclear Information System (INIS)

In this study the influence of process conditions for the plasma-enhanced chemical vapor deposition of SiOx diffusion barrier coatings on polypropylene (PP) is investigated and compared to results obtained on polyethylene terephthalate (PET). It was observed that the thermal load during deposition is much more crucial in the case of PP. If the thermal load is not the limiting factor, the composite parameter (CP) energy input per mass of precursor showed to be valuable to describe plasma conditions at constant oxygen to monomer ratio. Low oxygen transmission rates (OTRs) of 5.1 ± 3.6 and 0.3 ± 0.1 cm3/m2day/atm were achieved on PP and PET foil, respectively, for an optimal CP of 4.1 x 105 J/g. Fourier transform infrared (FTIR) spectroscopy revealed that low carbon and silanol content is necessary for good barrier performance. Low RF power, necessary to reduce thermal load on PP, can be compensated by increasing the oxygen to monomer ratio. For favorable plasma conditions, the dependence of the OTR on the coating thickness follows a similar trend for both substrate materials with a critical thickness of approximately 12 nm. The residual permeation can be correlated to the defect density at each stage of film growth by means of a simple correlation. Further support for permeation through defects is found by the activated rate theory, since the apparent activation energy of oxygen permeation is below typical values of amorphoution is below typical values of amorphous glasses and remains unchanged due to the deposition of SiOx on both substrates.

178

On the scratch deformation of micrometric wollastonite reinforced polypropylene composites  

Energy Technology Data Exchange (ETDEWEB)

Scratch deformation characteristics of neat and wollastonite-containing polypropylenes under identical test conditions are examined by electron microscopy and atomic force microscopy techniques. The study indicates that the severity of plastic deformation during scratch deformation in filled polypropylenes is a strong function of the debonding/detachment of wollastonite mineral particles from the polypropylene matrix. Scratch resistance is evaluated in terms of scratch hardness, scratch depth, average scratch roughness, thickness and density of the scratch tracks. Atomic force microscopy suggests the presence of a localized region surrounding the reinforcement particle that is characterized by enhanced crystal nucleation in which the local chain conformation and kinetics are likely to be different from regions that are a significant distance away from the mineral particle.

Dasari, A.; Rohrmann, J.; Misra, R.D.K

2004-01-15

179

On the scratch deformation of micrometric wollastonite reinforced polypropylene composites  

International Nuclear Information System (INIS)

Scratch deformation characteristics of neat and wollastonite-containing polypropylenes under identical test conditions are examined by electron microscopy and atomic force microscopy techniques. The study indicates that the severity of plastic deformation during scratch deformation in filled polypropylenes is a strong function of the debonding/detachment of wollastonite mineral particles from the polypropylene matrix. Scratch resistance is evaluated in terms of scratch hardness, scratch depth, average scratch roughness, thickness and density of the scratch tracks. Atomic force microscopy suggests the presence of a localized region surrounding the reinforcement particle that is characterized by enhanced crystal nucleation in which the local chain conformation and kinetics are likely to be different from regions that are a significant distance away from the mineral particle

180

Modification of polypropylene with radiation-treated wood fiber  

International Nuclear Information System (INIS)

The dispersed wood material is used not only as filler for thermosetting polymers but also as a new type of fibrous additive for thermoplastics e.g. polypropylene. Benefit of this additive (filler or reinforcement) is determined by the coupling between the wood and the synthetic resin. Fibrous, dispersed wood material was preirradiated in air, treated with vinyl monomer containing polyester resin and then mixed in polypropylene. Processability of such thermoplastic blends as well as reactivity of the mixed components were followed by measuring energy, absorbed during the kneading of the melt. The vinylmonomer vinylmonomer - polyester additive, activated at higher temperature by the radiation-formed peroxy groups on the wood fiber, results in good processability of the thermoplastic blend, and gives interesting mechanical properties. Calandering, extrusion, pressmoulding and mechanical testing demonstrated good workability and practical value of the polypropylene composite material containing radiation-treated wood fiber. (author)

 
 
 
 
181

Effect of Polypropylene Fiber on Properties of Concrete  

Directory of Open Access Journals (Sweden)

Full Text Available Plain concrete has low tensile strength, less ductility, destructive and brittle failure. In order to improve these properties of plain concrete, an attempt has been made to study the effect of addition polypropylene fiber in ordinary portland cement concrete. In the this experimental investigation fibers in different percentage 0 to 0.7% has been studied for the effect on strength properties of concrete by carrying compressive strength test and flexural strength test at 28 days for M25 grade of concrete. Test results show that the addition of polypropylene fiber to concrete exhibit better performance than the plain concrete. The results have shown improvement in compressive strength and flexural strength with the addition of polypropylene fiber in ordinary portland cement concrete The fiber content is vary from 0.1%, 0.3%, 0.5% and 0.7% by weight of concrete.

Vinay Kumar Singh

2014-12-01

182

Evaluation of five different suture materials in the skin of the earthworm (Lumbricus terrestris)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The purpose of this study was to determine which suture material is the most appropriate for dermal closure of terrestrial annelids. This paper describes the tissue reactions of the earthworm, Lumbricus terrestris, to five different types of suture materials in order to determine which suture material is the most appropriate for dermal closure. Silk, monofilament nylon, polydiaxonone, polyglactin 910, and chromic gut were studied. There was mild to moderate tissue reaction to all five suture ...

Salgado, Melissa A.; Lewbart, Gregory A.; Christian, Larry S.; Griffith, Emily H.; Law, Jerry Mchugh

2014-01-01

183

Production of the oxidation-resistant polypropylene track membranes  

International Nuclear Information System (INIS)

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

184

Properties of antibacterial polypropylene/nanometal composite fibers.  

Science.gov (United States)

Melt spinning of polypropylene fibers containing silver and zinc nanoparticles was investigated. The nanometals were generally uniformly dispersed in polypropylene, but aggregation of these materials was observed on fiber surface and in fiber cross-sections. The mechanical properties of the resulted composite fibers with low concentration of nanometal were comparable to those for the control PP yarns. Extruded composite fibers that contained 0.72% silver and 0.60% zinc nanoparticles had outstanding antibacterial efficacy as documented by the percentage count reduction growth of Escherichia coli and Staphylococcus aureus. Fibers containing silver particles had improved antistatic properties. PMID:21156104

Gawish, S M; Avci, H; Ramadan, A M; Mosleh, S; Monticello, R; Breidt, F; Kotek, R

2012-01-01

185

CCMR: Synthesis and Characterization of Poly(Propylene Carbonate)  

Science.gov (United States)

The focus of this work was to synthesize and characterize poly(propylene carbonate) made from CO2 and propylene oxide. Reactions were conducted in a high-pressure Parr reactor using a double metal cyanide catalyst and a poly(propylene glycol) initiator. The polymers were analyzed using GPC and 1H NMR. It was found that increasing the mol % of initiator in the reaction decreased molecular weight without affecting carbonate percentage. It was also determined that the increase of CO2 pressure in the reaction increased the amount of carbonate units in the polymer, without affecting molecular weight.

Dallinger, Gregory C.

2004-08-17

186

Synthesis and Modification of Polypropylene by Radiation-induced Grafting  

Directory of Open Access Journals (Sweden)

Full Text Available Polypropylene fiber (PP was radiation-induced graft polymerization of lauryl acrylate (LA and butyl acrylate (BAusing a 60Co gamma radiation source. Then the grafted polypropylene fiber was characterized by a Fourier transforminfrared (FT-IR spectrometer, Scanning Electron Microscopy (SEM, differential scanning calorimetry (DSC andthermogravimetry (TG, which indicated that LA and BA have been grafted onto PP. The article focused on somefactors that influenced on the graft degree, such as the cross-linking agent concentration, monomer concentration. Theresults showed that: the degree of grafting BA reached the maximum of 20.53%, while the maximum graft degree of LAwas 29.90%.

Feng Yuan

2009-02-01

187

Seismic wavespeed images across the Iapetus and Tornquist suture zones  

Science.gov (United States)

Closures of the Iapetus Ocean and the Tornquist Sea lead to the collision of the paleocontinents of Laurentia, Baltica and Eastern Avalonia during the Caledonian orogeny. It has been speculated that relicts of these two closures may be preserved within the crust or upper mantle. Over the past decades, numerous wide-angle seismic profiles were gathered in northwestern Europe to search for related subsurface features. Although active source studies revealed detailed crustal structures across the Iapetus and Tornquist suture zones, there are relatively few clear three-dimensional upper mantle images beneath this region. We use a new European crust and upper mantle model, EU30, determined based on continental scale, nonlinear adjoint tomography, to explore upper mantle structures across these two suture zones. Model EU30 reveals two fast anomalies within the upper mantle: one dips in a northwesterly direction down to approximately 400 km beneath the North Sea, and the other dips in a southwesterly direction down to nearly 250 km across the Tornquist Suture Zone. In addition, we observe a “gap” between the lithospheres of Laurentia and Eastern Avalonia across the Iapetus Suture Zone beneath the central British Isles. These seismic images suggest that heterogeneity related to the closures of the Iapetus Ocean and the Tornquist Sea have been preserved within the upper mantle over hundreds of millions of years.

Zhu, Hejun; Bozda?, Ebru; Peter, Daniel; Tromp, Jeroen

2012-09-01

188

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

189

Performing handsewn coloanal anastomosis with the pursestring suture anoscope.  

Science.gov (United States)

The pursestring suture anoscope, originally developed for the procedure for rectal prolapse and hemorrhoids, has been successfully used when performing coloanal anastomosis. The use of this tool for handsewn coloanal anastomosis can achieve relatively atraumatic results to the patient. It is a suitable and handy tool that makes handsewn transanal colonanal anastomosis simple and easy to perform. PMID:18597144

Chin, Chih-Chien; Huang, Wen-Shih; Yeh, Chung-Hung; Wang, Jeng-Yi

2008-09-01

190

Suture supported P C IOL in a homocystinuric child.  

Directory of Open Access Journals (Sweden)

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.

Bhatti S

1996-01-01

191

Surface modification of polypropylene and compatibilization of interfaces in incompatible blends of polypropylene with polystyrene by plasma of CO 2  

Science.gov (United States)

The effect of surface modification of polypropylene (PP) film is induced by CO 2 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 CO 2. Transition layer thickness is measured by small angle light scattering (SALS).

Ma, Gui-qiu; Liu, Xiang-ning; Huang, Ding-hai; Yuan, Xu-bo; Sheng, Jing

2009-06-01

192

In-vivo comparison of four absorbable sutures: Vicryl, Dexon Plus, Maxon and PDS.  

Science.gov (United States)

Absorbable sutures are initially equal or superior to nonabsorbable sutures in terms of tensile strength but are absorbed at variable rates by the action of hydrolysis. This study demonstrated that the in-vivo half-life tensile strength of the braided absorbable sutures polyglycolic acid (Dexon Plus) and polyglactin 910 (Vicryl) is 2 weeks, whereas those of the monofilament absorbable sutures polyglyconate (Maxon) and polydioxanone (PDS) are 3 and 6 weeks respectively. The addition of a single hitch or six knots reduced the in-vitro tensile strength by 30% to 35%. Polyglyconate (Maxon) suture demonstrated the best in-vitro knot security. PMID:2827875

Bourne, R B; Bitar, H; Andreae, P R; Martin, L M; Finlay, J B; Marquis, F

1988-01-01

193

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

Directory of Open Access Journals (Sweden)

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.

Morris C Phillip

2007-12-01

194

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)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

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

195

Adsorption of polypropylene from dilute solutions on a zeolite column packing.  

Science.gov (United States)

Faujasite type zeolite CBV-780 was tested as adsorbent for isotactic polypropylene by liquid chromatography. When cyclohexane, cyclohexanol, n-decanol, n-dodecanol, diphenylmethane, or methylcyclohexane was used as mobile phase, polypropylene was fully or partially retained within the column packing. This is the first series of sorbent-solvent systems to show a pronounced retention of isotactic polypropylene. According to the hydrodynamic volumes of polypropylene in solution, macromolecules of polypropylene should be fully excluded from the pore volume of the sorbent. Sizes of polypropylene macromolecules in linear conformations, however, correlate with the pore size of the column packing used. It is presumed that the polypropylene chains partially penetrate into the pores and are retained due to the high adsorption potential in the narrow pores. PMID:15688632

Macko, Tibor; Pasch, Harald; Denayer, Joeri F

2005-01-01

196

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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.

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

2006-06-01

197

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

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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.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-ray 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.

Lucilene B. de Paiva

2006-06-01

198

Broad-line NMR study of hot drawn polypropylene fibres  

International Nuclear Information System (INIS)

The influence of polypropylene fiber hot drawing on molecular mobility of polymer chains has been investigated by line broadening NMR method. Measurements have been done in the temperature range (200-420 K) where ?-relaxation processes in non crystalline regions are dominant and deformation are mostly probable

199

Broad-line NMR study of hot drawn polypropylene fibres  

Energy Technology Data Exchange (ETDEWEB)

The influence of polypropylene fiber hot drawing on molecular mobility of polymer chains has been investigated by line broadening NMR method. Measurements have been done in the temperature range (200-420 K) where {beta}-relaxation processes in non crystalline regions are dominant and deformation are mostly probable. 10 refs, 3 figs, 1 tab.

Mucha, L.; Murin, J.; Sevcovic, L. [Dept. of Physics, Technical Univ., Kosice (Slovakia)

1994-12-31

200

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

 
 
 
 
201

Irradiation effects on the weldability and adhesiveness of polypropylene  

International Nuclear Information System (INIS)

This paper describes the irradiation effects on the tensile characteristics of welded polypropylene and on the adhesiveness of this material. Polypropylene plates of 2 mm in thickness were but welded by using a semiautomatic heating plate welder and exposed to various irradiation doses of neutron. Tensile characteristics of these specimens were examined and measurements of melting point, dissolution rate and molecular weight were made. Examination of X-ray diffraction patterns was also made during tensile tests on neutron-irradiated specimens. Furthermore, the adhesive strength, infrared spectra and surface appearance of neutron-irradiated specimens were examined, and the irradiation effect on the adhesiveness of this materials was also discussed. The results obtained were summarized as follows; (1) The irradiation effects for the welded part are similar to those for the base material of polypropylene, that is, tensile strength decreases with excessive irradiation and brittleness becomes greater with an increase of irradiation dose. (2) The irradiation effects on the melting point, dissolution rate, molecular weight and molecular orientation tendency are correlative with those on the tensile characteristics of neutron-irradiated materials. (3) The adhesive strength of polypropylene increases with irradiation of neutron. This increase seems to be caused by polarization due to irradiation. (author)

202

Nanogels and microgels of polypropylene obtained by gamma irradiation  

International Nuclear Information System (INIS)

In preparation of HMS-PP (polypropylene modified by gamma irradiation), we use the iPP (isotactic polypropylene) in pellets, which was packaged in plastic container an then irradiated with 60Co gamma source containing acetylene pressure of 110 kPa and at doses of 5, 12.5 and 20 kGy. The gel fraction of the samples was determined by extraction of soluble components in boiling xylene for 12 hours at 138 deg C. The soluble portion of the sample was decanted with the total volatilization of xylene at room temperature (25 deg C) and deposited on glass slides. These samples were characterized by: scanning electron microscopy, scanning electron microscope with field emission. In this study the morphology, we obtained the formation of microgels with a higher incidence of polypropylene in PP 12.5 kGy and 20 kGy. Also it was found nanoscale structures of gels of polypropylene (nanogels) in samples of PP 12.5 kGy. (author)

203

PLASTIC SHRINKAGE CONTROLLING EFFECT BY POLYPROPYLENE SHORT FIBER WITH HYDROPHILY  

Science.gov (United States)

The aim of this research is to clarify the mechanism of controlling plastic shrinkage crack by adding small amout of synthetic short fiber, and to propose optimum polypropylene short fiber to control plastic shrinkage crack. In this research, the effect of the hydrophily of polypropylene fiber was investigated in the amount of plastic shrinkage of mortar, total area of plastic shrinkage crack, and bond properties between fiber and mortar. The plastic shrinkage test of morar was conducted under high temperature, low relative humidity, and constant wind velocity. When polypropylene fiber had hydrophily, the amount of plastic shrinkage of mortar was restrained, which was because cement paste in morar was captured by hydrophilic fiber and then bleeding of mortar was restrained. With hydrophily, plastic shrinkage of mortar was restrained and bridging effect was improved due to better bond, which led to remarkable reduction of plastic shrinkage crack. Based on experimental results, the way of developing optimum polypropylene short fiber for actual construction was proposed. The fiber should have large hydrophily and small diameter, and should be used in as small amount as possible in order not to disturb workability of concrete.

Hosoda, Akira; Sadatsuki, Yoshitomo; Oshima, Akihiro; Ishii, Akina; Tsubaki, Tatsuya

204

Effects of gamma irradiation on the physical properties of laminated packaging materials. 2. polypropylene-polypropylene, polypropylene-polyethylene, and polyester-polyethylene  

International Nuclear Information System (INIS)

This experiment was done to determine the effects of irradiation on the physical properties of three kinds of laminated packaging materials, i.e. polypropylene-polypropylene, polypropylene-polyethylene, polyester-polyethylene. Observations were made on pinhole production, leakage, oil resistance, resistance against insect penetration, colour, odour tensile strength, elongation at break, seal strength and tear resistance. The samples were irradiated with doses of 0, 5 and 10 kGy, then stored at room temperature and examined after 0, 3, 6 and 12 months of storage. The results showed that irradiation doses up to 10 kGy, as well as storage up to 12 months, did not create pinholes, or leakage in pouches prepared from laminated films. The resistance of the films to oil and insect penetration, the colour, and the odour were also unchanged. Both irradiation and storage treatments had a significant effect on physical properties of the laminated films. In general, the changes started to be significant after 6 months' storage either in unirradiated samples or in irradiated ones. It could be concluded that irradiation with doses up to 10 kGy had no meaningful effect on the physical strength of the laminated films, therefore such films could be used as packaging materials for irradiated foods. (author)

205

Rheometric research of polypropylene Licocene PP2602 melts  

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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.

V.V. Romanuke

2011-07-01

206

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

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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

Fernandes MA

2014-02-01

207

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)

208

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  

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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...

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

2009-01-01

209

HUESOS SUTURALES EN EL PTERION / SUTURAL BONES IN THE PTERION  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish 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

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

210

Local tissue reaction to implantation of biodegradable suture materials.  

Science.gov (United States)

Morphological changes in tissues adjacent to the implant were studied 1, 2, 6, and 12 months after implantation of biodegradable suture materials (catgut thread, DemeTECH polyfilament thread, and Surgilactin monofilament thread) into subcutaneous fat of rats. Tissue reaction to implantation of different suture materials developed as usual in response to a wound process and to a foreign body. By the end of month 1. the stage of traumatic perifocal inflammation was replaced in all groups by the proliferative phase with formation of new vessels and connective tissue. A trend to reduction of the productive inflammation activity from month 1 to month 12 was noted. Complete degeneration of the material after 12 months with complete recovery of the histoarchitecture of the adjacent tissues (restitution) was detected only after implantation of DemeTECH polyfilament thread. PMID:25065322

Kuznetsova, I V; Maiborodin, I V; Shevela, A I; Barannik, M I; Manaev, A A; Brombin, A I; Maiborodina, V I

2014-07-01

211

Facial Asymmetry Correction in Facial Palsy Patients with Silhouette Sutures  

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Full Text Available Introduction: over the last few decades several techniques static and dynamics, have been performed to improve facial asymmetry and functionality alter suffering facial paralysis. Methods: we present a pilot study to show and evaluate the benefits of a new form of facial suspension, with Silhouette sutures. We performed two patients with total and complete facial palsy due to otical tuberculosis in one case and to parotid carcinoma in the other. Results: one year after surgery, both patients have improved facial asymmetry, mastication and speech production which have lead to a higher self-esteem and major social interaction. Conclusions: static facial suspension with Silhouette sutures is a non invasive alternative to dynamic techniques in patients who don’t want or can’t undergo more complex surgeries.

Juan Fernando Fuentes

2012-01-01

212

Facial Asymmetry Correction in Facial Palsy Patients with Silhouette Sutures  

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Introduction: over the last few decades several techniques static and dynamics, have been performed to improve facial asymmetry and functionality alter suffering facial paralysis. Methods: we present a pilot study to show and evaluate the benefits of a new form of facial suspension, with Silhouette sutures. We performed two patients with total and complete facial palsy due to otical tuberculosis in one case and to parotid carcinoma in the other. Results: one year after surgery, both patients ...

Juan Fernando Fuentes; Lluisa Torrent; Ricard Palao; María Luisa Navarrete; Mireia González

2012-01-01

213

Primary thoracoscopic repair of diaphragmatic hernia with pericostal sutures.  

Science.gov (United States)

The surgical management of congenital diaphragmatic hernias has traditionally been via laparotomy or thoracotomy. Although laparoscopic and thoracoscopic repairs have been described, most reports are in older infants. We describe a method for primary thoracoscopic repair applied in the immediate neonatal period when no posterolateral rim of diaphragm exists. This simple technique for placing the pericostal sutures is a useful adjunct in the thoracoscopic management of diaphragmatic hernias. PMID:16366880

Rozmiarek, Andrew; Weinsheimer, Robert; Azzie, Georges

2005-12-01

214

[The prospects for using new suture materials in emergency gynecology].  

Science.gov (United States)

The results of using new bactericidal suturing material, Etikon (Germany), in 534 urgent surgical gynecological interventions are analyzed. Employment of new dissolving surgical threads helped reduce threefold the incidence of postoperative complications and almost 1.5-times the mean hospital stay after surgery. A favorable course of the postoperative period is explained by a more swift healing of the operation wound and reduction of the rate of postoperative complications. PMID:1814231

Kulakov, V I; Abramian, R A

1991-11-01

215

Efficacy of b-lynch brace suture in postpartum haemorrhage  

International Nuclear Information System (INIS)

Massive uncontrolled haemorrhage after childbirth is the leading cause of maternal death in developing countries. Postpartum haemorrhage is traditionally defined as blood loss of more than 500 ml after vaginal delivery and more than 1000 ml after caesarean section, but intraoperative estimation of blood loss is inaccurate. Uterine atony alone accounts for 75 - 90% of PPH. To estimate the effectiveness and safety of B-Lynch brace Suture in the management of primary postpartum haemorrhage (PPH). (author)

216

ADJUSTABLE SUTURE STRABISMUS SURGERY: A REVIEW OF 850 CASES  

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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.

M.E. Latronico

2010-11-01

217

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)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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

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

2003-06-01

218

Effect on early tear film function of different adjustable suture in glaucoma trabeculectomy  

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Full Text Available AIM:To compare the effects of different adjustable suture in glaucoma trabeculectomy on early tear film function. METHODS: Sixty-eight cases of primary glaucoma(76 eyesduring January 2012 to June 2014 in our hospital were selected and divided into exposure conjunctival suture group(34 cases, 36 eyesand embedded conjunctival suture group(34 cases, 40 eyesaccording to treatment. Adjustable suture exposed conjunctival suture and embedding conjunctival suture was given to two groups, respectively. Intraocular pressure(IOPbefore and after treatment 7, 14, 30d were observed and Schirmer test, tear break-up time, No Hikaru sensitivity and the occurrence of adverse reactions after treatment 1, 30d were recorded. RESULTS: After the treatment, the mean IOP of two groups were decreased significantly(PP>0.05, after treatment 7, 14, 30d embedded conjunctival suture group was significantly higher than that of exposure conjunctival suture group(PPPPCONCLUSION:Trabeculectomy operation with adjustable thread embedding conjunctival suture has few effects on the tear film function in patients with early postoperative complications, lower, and operation effect is better than that of exposed conjunctival suture.

Zhen-Hua Ge

2015-01-01

219

Ultrastructure, Histochemistry, and Mineralization Patterns in the Ecdysial Suture of the Blue Crab, Callinectes sapidus  

Science.gov (United States)

The ecdysial suture is the region of the arthropod exoskeleton that splits to allow the animal to emerge during ecdysis. We examined the morphology and composition of the intermolt and premolt suture of the blue crab using light microscopy and scanning electron microscopy. The suture could not be identified by routine histological techniques; however 3 of 22 fluorescein isothiocyanate-labeled lectins tested (Lens culinaris agglutinin, Vicia faba agglutinin, and Pisum sativum agglutinin) differentiated the suture, binding more intensely to the suture exocuticle and less intensely to the suture endocuticle. Back-scattered electron (BSE) and secondary electron observations of fracture surfaces of intermolt cuticle showed less mineralized regions in the wedge-shaped suture as did BSE analysis of premolt and intermolt resin-embedded cuticle. The prism regions of the suture exocuticle were not calcified. X-ray microanalysis of both the endocuticle and exocuticle demonstrated that the suture was less calcified than the surrounding cuticle with significantly lower magnesium and phosphorus concentrations, potentially making its mineral more soluble. The presence or absence of a glycoprotein in the organic matrix, the extent and composition of the mineral deposited, and the thickness of the cuticle all likely contribute to the suture being removed by molting fluid, thereby ensuring successful ecdysis.

Priester, Carolina; Dillaman, Richard M.; Gay, D. Mark

2005-12-01

220

Histopathologic comparison of chromic catgut suture materials from Iran and abroad  

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Full Text Available (Received 19 December, 2009 ; Accepted 3 April, 2010AbstractBackground and purpose: The chromic catgut sutures are the most common suture materials in surgical operations. The purpose of this in-vivo study was to evaluate the histopathological inflammatory reaction incited by four different kinds of catgut suture materials. Materials and methods: Twenty five adult New Zealand White rabbits, weighing approximately 2-3 kg, were divided into 5 groups of 5 rabbits in each group. Four types of catgut sutures were implanted in the dorsum and thigh muscles. After 2, 7, 14, 21 and 60 days, the animals were sacrificed and the sutures, subcutaneous and muscle tissues were removed from the implanted areas.Results: Statistical analysis for comparison of each two suture materials showed significant differences between groups (p<0.05 while ETHICON suture showed minimum inflammatory reaction and was considered the best. Conclusion: Uncontrolled raw materials of the catgut suture from the intestine of particular animals may cause a variety of pathological effects beyond the threshold set for medical surgery.Key words: Chromic catgut suture, implantation, suture material, pathology, rabbitJ Mazand Univ Med Sci 2009; 20(74: 33-42 (Persian.

Mehdi Marjani

2009-01-01

 
 
 
 
221

Polypropylene/calcium carbonate nanocomposites – effects of processing techniques and maleated polypropylene compatibiliser  

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Full Text Available The mechanical properties and crystalline characteristics of polypropylene (PP and nano precipitated calcium carbonate (NPCC nanocomposites prepared via melt mixing in an internal mixer and melt extrusion in a twin screw extruder, were compared. The effect of maleic anhydride grafted PP (PP-g-MAH as a compatibiliser was also studied using the internal mixer. At low filler concentration of 5 wt%, impact strength was better for the nanocomposites produced using the internal mixer. At higher filler loading of more than 10 wt%, the extrusion technique was more effective to disperse the nanofillers resulting in better impact properties. The impact results are consistent with the observations made from Scanning Electron Microscope (SEM morphology study. As expected, the flexural modulus of the nanocomposites increased with filler concentration regardless of the techniques utilised. At a same filler loading, there was also no significant difference in the moduli for the two techniques. The tensile strength of the mixed nanocomposites were found to be inferior to the extruded nanocomposites. Introduction of PP-g-MAH improved the impact strength, tensile strength and modulus of the mixed nanocomposites. The improvements may be attributed to better interfacial adhesion, as evident from the SEM micrographs which displayed better dispersion of the NPCC in the presence of the compatibiliser. Though NPCC particles have weak nucleating effect on the crystallization of the PP, addition of PP-g-MAH into the mixed nanocomposites has induced significant crystallization of the PP.

2010-10-01

222

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)

223

Functionalization of silica nanoparticles for polypropylene nanocomposites applications  

Energy Technology Data Exchange (ETDEWEB)

Synthetic silica nanospheres of different diameters produced via the sol-gel method were used in order to enhance the barrier properties of the polypropylene-silica nanocomposites. Modification of the silica surface by reaction with organic chlorosilanes was performed in order to improve the particles interaction with the polypropylene matrix and its dispersion. Unmodified and modified silica nanoparticles were characterized using electronic microscopy (TEM), elemental analysis, thermo gravimetric analysis (TGA), and solid state nuclear magnetic resonance (NMR) spectroscopy. Preliminary permeability tests of the polymer-silica nanocomposite films showed no significant change at low particles load (3 wt%) regardless its size or surface functionality, mainly because of the low aspect ratio of the silica nanospheres. However, it is expected that at a higher concentration of silica particles differences will be observed. (author)

NONE

2011-07-01

224

Effects of environmental ageing on HMS-polypropylene/Cloisite nanocomposites  

Energy Technology Data Exchange (ETDEWEB)

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.

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

225

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

226

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 ?m) 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

227

Analysis of the fracture behavior of polypropylene: sawdust composites  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

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

2005-06-01

228

Oxygen barrier property of polypropylene-polyether treated clay nanocomposite  

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Full Text Available Polypropylene (PP nanocomposites were obtained by solution blending of polyether treated montmorillonite and PP, with a coupling agent of maleic anhydride grafted polypropylene (PP-g-MA. The composition of the inorganic clay was varied in 1, 2 and 5 phr (parts of clay per hundred of PP by mass while films of the composites were obtained via compression molding. Wide-angle X-ray scattering (WAXS showed nanocomposites in which silicate layers were exfoliated and intercalated with respect to the different clay ratios. The morphology and gas permeability of hybrids prepared with organoclay were compared. Morphological studies using transmission electron microscopy showed most clay layers were dispersed uniformly in the PP matrix. Some tactoids of agglomerated nanoparticles were detected, as clay content increased. The oxygen permeability for all the hybrids for clay loadings were reduced by 30% of the corresponding values for pure PP.

2008-06-01

229

Mechanical properties of pineapple leaf fibre reinforced polypropylene composites  

Energy Technology Data Exchange (ETDEWEB)

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.

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

230

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

231

Effects of environmental ageing on HMS-polypropylene/Cloisite nanocomposites  

Science.gov (United States)

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.

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

2014-05-01

232

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)

233

Radiation resistant polypropylene blended with mobilizer, antioxidants and nucleating agent  

International Nuclear Information System (INIS)

Post-irradiation storage of medical disposables prepared from isotactic polypropylene renders them brittle due to degradation. To avoid this, isotactic polypropylene [(is)PP] was blended with a mobilizer, dioctyl pthallate (DOP), three antioxidants (hindered amines and a secondary antioxidant) and benzoic acid to obtain radiation-resistant, thermally-stable and transparent material. Different formulations prepared were subjected to gamma radiation to doses of 25 and 50 kGy. Tests of breakage on bending after ageing in an oven at 70 deg. C up to 12 months have shown that the addition of DOP and the antioxidants imparts improved radiation and thermal stability as compared to (is)PP alone or its blend with DOP. All the formulations irradiated or otherwise demonstrated excellent colour stability even after accelerated ageing at 70 deg. C for prolonged periods. (author)

234

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

235

Orientation of late Precambrian sutures in the Arabian-Nubian shield  

Science.gov (United States)

Recent tectonic models have resulted in conflicting descriptions of how the late Precambrian sutures of the Arabian-Nubian shield extend into northeast Africa. The Hamisana shear zone in northeastern Sudan is critical to this discussion because it truncates and disrupts two sutures, the Allaqi-Heiani and the Onib-Sol Hamed. Analysis of field structural data, Thematic Mapper imagery, and Rb-Sr and U-Pb geochronology suggests that the Allaqi-Heiani suture is the western extension of the Onib-Sol Hamed suture and that both make up the exposed parts of a far-traveled, polydeformed ophiolitic nappe complex. Subsequent deformation localized in the Hamisana shear zone disrupted this nappe and displaced the suture between 660 and 550 Ma during regional deformation associated with the Najd fault system. These results indicate that at least one suture extends westward into the interior of northern Africa.

Stern, Robert J.; Nielsen, Kent C.; Best, Eric; Sultan, Mohamed; Arvidson, Raymond E.

1990-01-01

236

Polypropylene grafted with glycidyl methacrylate using supercritical CO2 medium  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ethylenedi...

Kunita, M. H.; Girotto, E. M.; Muniz, E. C.; Rubira, A. F.

2006-01-01

237

Morphology and mechanical properties of polypropylene-wood flour composites  

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The microstructure and mechanical properties of polymer composites based on polypropylene and wood flour modified with monochloroacetic acid were investigated. Scanning electron microscopy and wide-angle X-ray diffraction were used as methods to probe the composite microstructures, while the tensile test was used to measure the physical strength. The wood flour modification was performed at different levels of monochloroacetic acid, ranging from 0.01 to 1 mol, while the modified wood flour ...

Vasileva, St; Nenkova, S.; Dobreva, D.

2006-01-01

238

Upgrading of recycled polypropylene by preparing flame retarded layered composite  

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Upgrading of polypropylene waste was performed by different composite technologies, in order to improve the flame retardancy combined with preserved or improved mechanical properties. The polymer waste of density below 900 kg/m3 is originated from end-of-life vehicles (ELV) after comminution, density separation and comprehensive analysis. Intumescent flame retardant system was used for reducing the flammability; while chopped glass fibre reinforcement was used to compensate the deterioration ...

Ronkay, F.; Gy. Marosi; Toldy, A.; Bodzay, B.; Fejos, M.; Bocz, K.

2012-01-01

239

On Polyethylene Chain Generation Through Chemical Crosslinking of Isotactic Polypropylene  

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Crosslinked isotactic polypropylene (iPP) was prepared by reactive blending using dicumyl peroxide and active sulfur. The modified material was characterized by means of several techniques: dynamic mechanical thermal analysis, differential scanning calorimetry,Fourier transform infrared spectroscopy, and nuclear magnetic resonance (13C solid state NMR). Analysis of results using the above techniques confirms that, during the crosslinking process, new ethylenic chains are generated at expen...

Bouhelal, Sai?d; Cagiao, M. Esperanza; Bartolotta, Antonio; Di Marco, Gaetano; Garrido, Leoncio; Benachour, Djafer; Balta? Calleja, Francisco J.

2010-01-01

240

Graft copolymerization of methacrylic acid monomers onto polypropylene fibers  

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In recent years, graft copolymerization has been widely used to insert various functional groups onto polymers. In our study, methacrylic acid monomers are grafted to polypropylene (PP) fibers to make them hydrophilic while maintaining their mechanical properties. Experiments are designed based on Taguchi’s method and influence of temperature, monomer concentration; cross-linker concentration and time of reaction are investigated. Grafting of methacrylic ...

Mazhar Majid; Abdouss Majid; Shariatinia Zahra; Zargaran Mojdeh

2014-01-01

 
 
 
 
241

Aqueous Processes for Dyeing Generic, Unmodified Polypropylene Fiber  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Gupta, Murari L.; Fred Cook

2010-01-01

242

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)

243

Crystallization kinetics of polypropylenes. Effect of nucleating agents?  

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Thermal conditions and formulation affect the crystallization mechanisms of polymers and the associated kinetics in a coupled manner. In that field, the objective of this investigation is to compare overall crystallization kinetics and structural organization of one clarified polypropylene (specifically designed for stretch-blow molding) and a homopolypropylene. Liquid/solid transitions are investigated in- and ex-situ under isothermal and non-isothermal conditions combining crossed-polarized...

Boyer, Se?verine A. E.; Billon, Noelle; Haudin, Jean-marc

2008-01-01

244

Microstructure and mechanical properties of Polypropylene/Polycarbonate blends  

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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 ...

Viana, J. C.; Bilewicz, M.; Kro?l, M.; Dobrzan?ski, L. A.

2008-01-01

245

Property Relationship in Organosilanes and Nanotubes Filled Polypropylene Hybrid Composites  

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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 hal...

Monsiva?is-barro?n, Alejandra J.; Jaime Bonilla-Rios; Antonio Sánchez-Fernández

2014-01-01

246

The nonlinear time-dependent response of isotactic polypropylene  

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Tensile creep tests, tensile relaxation tests and a tensile test with a constant rate of strain are performed on injection-molded isotactic polypropylene at room temperature in the vicinity of the yield point. A constitutive model is derived for the time-dependent behavior of semi-crystalline polymers. A polymer is treated as an equivalent network of chains bridged by permanent junctions. The network is modelled as an ensemble of passive meso-regions (with affine nodes) and ...

Drozdov, A. D.; Christiansen, J. Dec

2002-01-01

247

Bacterial Growth on Chitosan-Coated Polypropylene Textile  

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Biofouling is a problem common in all systems where microorganisms and aqueous environment meet. Prevention of biofouling is therefore important in many industrial processes. The aim of this study was to develop a method to evaluate the ability of material coating to inhibit biofilm formation. Chitosan-coated polypropylene nonwoven textile was prepared using dielectric barrier discharge plasma activation. Resistance of the textile to biofouling was then tested. First, the textile was submerge...

Erben, D; Hola, V.; Jaros, J.; Rahel, J.

2012-01-01

248

Mechanical properties of polypropylene/calcium carbonate nanocomposites  

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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...

Daniel Eiras; Luiz Antonio Pessan

2009-01-01

249

Reinforcing Efficiency of Crimped Profile of Polypropylene Fibres on the Cementitious Matrix  

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Fibre reinforcement in concrete is an effective solution for improving tensile properties of concrete. Different types of fibres such as steel, polypropylene, glass and polyester were commonly used in concrete. In the present study, the effect of adding crimped polypropylene fibres on the improvement in the compressive properties of hardened concrete was studied. Crimped polypropylene fibres with different levels of reinforcements index was investigated systematically with designed concrete m...

Thirumurugan, S.; Sounthararajan, V. M.; Sivakumar, A.

2013-01-01

250

Effect of recycling on properties of rice husk-filled-polypropylene  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This research concerned with the use of rice husk (Oryza sativa) as a filler for polypropylene and its recycle ability. Rice husk (200 mesh and 40% by weight) and polypropylene were compounded in a twinscrew extruder and injection moulding technique was applied in order to obtain testing specimens. It was found that tensile, flexural and impact properties as well as % water absorption of the rice husk-filled polypropylene were only slightly dropped upon recycling process, presenting the abili...

Jutarat Prachayawarakorn; Niracha Yaembunying

2005-01-01

251

Comparative study between two techniques of incisional hernia repair with polypropylene mesh in rabbits Estudo comparativo entre duas técnicas de tratamento da hérnia incisional em coelhos utilizando a tela de polipropileno  

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Full Text Available PURPOSE: To compare two different incisional hernia repair techniques (repair with a polypropylene mesh reinforcement on the peritonium-aponeurosis versus polypropylene mesh sutured to the borders of the hernial ring as a bridge in rabbits. METHODS: Incisional hernia was experimentally developed through a 4-cm median incision in 60 rabbits. After 30 days, half of the animals were operated for primary wall closure and placement of a polypropylene mesh reinforcement, while the other half had a polypropylene mesh sutured to the borders of the hernial ring as a bridge. Clinical development, scar breaking strength, as well as gross, microscopic and morphometric parameters were evaluated in all animals 30, 60, and 90 days after repair. RESULTS: No significant differences in breaking strength or histological parameters were observed between groups at any time point studied. No statistical difference regarding complications was detected, although denser and firmer adhesions to the abdominal wall were seen after the mesh was placed as a " bridge" . CONCLUSIONS: No significant differences between the incisional hernia repair techniques assessed were observed regarding breaking strength, and histological and morphometric parameters. The number of complications was similar in both study groups. However, adhesion of abdominal cavity organs to the scar area was much denser after the placement of a mesh to bridge the defect.OBJETIVO: Comparar duas técnicas de tratamento da hérnia incisional em coelhos utilizando a tela de polipropileno apoiando um reforço peritônio - aponeurótico ou suturada nas bordas do anel herniário 'em ponte" . MÉTODOS: Foram operados 60 coelhos para a produção de hérnia incisional, em uma incisão mediana de 4 centímetros. Após 30 dias, metade dos animais foram operados com o fechamento primário da parede, com colocação de uma tela de polipropileno apoiando o reforço e a outra metade dos animais com a colocação da tela suturada nas bordas do anel herniário " em ponte" . Os animais foram avaliados com 30 (M1, 60 (M2e 90 (M3 dias de pós-operatório. Os parâmetros analisados foram a evolução clínica, análise da força de ruptura da cicatriz, estudo macroscópico, análise microscópica e morfométrica. RESULTADOS: Não foram observadas diferenças significantes com relação a força de ruptura e estudos histológicos nos dois grupos e vários momentos estudados. Não houve diferença estatística com relação às complicações, embora os animais que receberam a tela " em ponte" tiveram aderências mais firmes e intensas à parede abdominal. CONCLUSÕES: As duas técnicas utilizadas para correção da hérnia incisional em coelhos não mostraram diferenças significantes quanto a força de ruptura, análise histológica e morfométrica. O número de complicações foi semelhante, porém a aderência de órgãos da cavidade abdominal à área de cicatriz foi muito mais intensa no grupo em que a tela foi colocada " em ponte" .

José Guilherme Minossi

2010-10-01

252

Pubovaginal sling with a low-cost polypropylene mesh  

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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.

Fransber R. Rodrigues

2007-10-01

253

Mixing of Isotactic and Syndiotactic Polypropylenes in the Melt  

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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.

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

2000-07-14

254

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)

255

Surface modification of polypropylene membrane by polyethylene glycol graft polymerization.  

Science.gov (United States)

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. PMID:25063140

Abednejad, Atiye Sadat; Amoabediny, Ghasem; Ghaee, Azadeh

2014-09-01

256

Effects of radiation on the structure of polypropylene  

International Nuclear Information System (INIS)

The effects of high-energy radiation on the physical arrangement of macromolecules in atactic polypropylene (aPP) and radiation-amorphized isotactic polypropylene (iPP) were examined using the differential radial distribution function (DRDF) technique. The resultant DRDF curve for 0 Mrad aPP showed three intermolecular peaks at 6.6, 13.0, and 17.7 A and two intramolecular peaks at 1.5 and 2.5 A. The appearance of the periodic intermolecular DRDF peaks suggested the packing of parallel chains of --18 A in the polymer. The 17.7 A peak disappeared when the aPP sample was irradiated to 115 Mrad, indicating the occurrence of structure deterioration from 18 A to 13 A. As a result of severe deterioration of the intermolecular organization, DRDF curves for 400 and 1300 Mrad iPP samples each showed only one intermolecular peak at --7 A. This deterioration was attributed to the crosslinking-induced increase in lattice distortions. The results were compared with previous studies on irradiation of natural rubber (NR) and polyethylene (PE). It appears that radiation was more effective in causing deterioration of the intermolecular organization in polypropylene than in NR and PE. This was explained by the different radiation chemistry of the polymers. (author)

257

Property Relationship in Organosilanes and Nanotubes Filled Polypropylene Hybrid Composites  

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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.

Alejandra J. Monsiváis-Barrón

2014-10-01

258

Contact angle analysis of corona treated polypropylene films  

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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.

Vlaeva, I.; Yovcheva, T.; Viraneva, A.; Kitova, S.; Exner, G.; Guzhova, A.; Galikhanov, M.

2012-12-01

259

SUTURES USING POLYGLACTIN 910 AND TITANIUM STAPLES: URINARY AND UROLITHOGENIC ASPECTS IN EXPERIMENTAL ILEOCYSTOPLASTIES IN DOGS  

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Urinary disorders are an important finding in ileocystoplasty, especially uroliths and crystalluria, and partly related to the type of suture material involved in this procedure. The aim of this study was to determine whether there are differences in the formation of uroliths and urinary crystalloid after ileocystoplasty in dogs, performed by suturing with nonabsorbable titanium staples and suture with polyglactin 910, noting their impact on renal function and urinary changes in the constitut...

Gabriela Silva Uchôa; Danilo Ferreira Rodrigues; Sidney Castro Abreu; Naida Cristina Borges; Dirson Vieira; José Belarmino da Gama Filho; Neusa Margarida Paulo

2011-01-01

260

Unidirectional barbed suture versus standard monofilament for urethrovesical anastomosis during robotic assisted laparoscopic radical prostatectomy  

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PURPOSE: V-LocTM180 (Covidien Healthcare, Mansfield, MA) is a new unidirectional barbed suture that may reduce loss of tension during a running closure. We evaluated the use of the barbed suture for urethrovesical anastomosis (UVA) during robotic assisted laparoscopic prostatectomy (RALP). Time to completion of UVA, post-operative anastomotic leak rate, and urinary incontinence were compared in patients undergoing UVA with 3-0 unidirectional-barbed suture vs. 3-0 MonocrylTM (Ethicon, Somervil...

Marc Manganiello; Patrick Kenney; David Canes; Andrea Sorcini; Alireza Moinzadeh

2012-01-01

 
 
 
 
261

Nonabsorbable-Suture-Induced Osteomyelitis: A Case Report and Review of the Literature  

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We are reporting a case of nonabsorbable suture-induced osteomyelitis in patient who had an open rotator cuff repair with nonabsorbable Ethibond anchor suture. Patient in this case presented with very subtle clinical features of osteomyelitis of the left proximal humerus 15 years after initial rotator cuff repair surgery. Literature had shown that deep infection following rotator cuff repairs, although rare, can be easily missed and can cause severe complications. Absorbable suture had been d...

Cheng Hong Yeo; Russell, Nick C.; Tom Sharpe

2012-01-01

262

Cystoscopic suture removal by Holmium-YAG laser after Burch procedure  

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Burch colposuspension remains one of the successful operations performed for stress incontinence. Accidental suturing of the bladder wall during the procedure or subsequent erosion may lead to lower urinary tract symptoms. Diagnosis and management of these sutures indicate precise evaluation for which a 70 degree cystoscope is used. In selected cases, Holmium-YAG laser may enable us to manage long-standing, encrustated neglected sutures. Here we would like to report successful removal of intr...

?skender Ba?er; Erol Mutlu; Mutlu Cihangir Ercan; ?brahim Alanbay; Sertaç Esin; Emre Kaz?m Kara?ahin; ?eref Basal

2011-01-01

263

Surgery effect of endoscope-assisted transscleral suture fixation intraocular lens  

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AIM: To research surgery effect and complications of transscleral suture fixation intraocular lens(IOL)assisted with endoscope or with the traditional method. METHODS: Thirty cases need IOL implantation without sufficient posterior lens capsule membrane support were chosen. These patients were divided into two groups randomly and every group had 15 patients. Group A underwent surgery of transscleral suture fixation IOL with the traditional method. Group B had surgery of transscleral suture...

Hai-Jun Yang; Jing-Lin Yi; Xing-Zhong Luo; Hui Xie; Yong-Quan Bai; Min Zhou

2013-01-01

264

Microbiology of Explanted Suture Segments from Infected and Noninfected Surgical Patients  

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Sutures under selective host/environmental factors can potentiate postoperative surgical site infection (SSI). The present investigation characterized microbial recovery and biofilm formation from explanted absorbable (AB) and nonabsorbable (NAB) sutures from infected and noninfected sites. AB and NAB sutures were harvested from noninfected (70.9%) and infected (29.1%) sites in 158 patients. At explantation, devices were sonicated and processed for qualitative/quantitative bacteriology; selec...

Edmiston, Charles E.; Krepel, Candace J.; Marks, Richard M.; Rossi, Peter J.; Sanger, James; Goldblatt, Matthew; Graham, Mary Beth; Rothenburger, Stephen; Collier, John; Seabrook, Gary R.

2013-01-01

265

Metallurgically bonded needle holder jaws. A technique to enhance needle holding security without sutural damage.  

Science.gov (United States)

A new needle holder jaw face has been specifically designed and developed to increase needle holding security without sutural damage. Tungsten carbide particles have been metallurgically bonded into the stainless steel jaw to create a fine granular surface. This bonded jaw enhances needle holding security by limiting either twisting or rotation of the clamped needle. In addition, compression of the monofilament synthetic sutures by the bonded jaws does not reduce suture breaking strength. PMID:2221617

Abidin, M R; Dunlapp, J A; Towler, M A; Becker, D G; Thacker, J G; McGregor, W; Edlich, R F

1990-10-01

266

Histopathologic comparison of chromic catgut suture materials from Iran and abroad  

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(Received 19 December, 2009 ; Accepted 3 April, 2010)AbstractBackground and purpose: The chromic catgut sutures are the most common suture materials in surgical operations. The purpose of this in-vivo study was to evaluate the histopathological inflammatory reaction incited by four different kinds of catgut suture materials. Materials and methods: Twenty five adult New Zealand White rabbits, weighing approximately 2-3 kg, were divided into 5 groups of 5 rabbits in each group. Four types of ca...

Mehdi Marjani; Masoud Hashemi; Reza Sedaghat

2009-01-01

267

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)

268

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

Energy Technology Data Exchange (ETDEWEB)

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.

Dasari, A.; Misra, R.D.K

2004-04-05

269

Effect of ?-irradiation on the structure, stability and transport properties of polypropylene membrane and Cyanex-301  

International Nuclear Information System (INIS)

Polypropylene supported liquid membrane of Cyanex-301 was found to be promising for the separation of trivalent actinides and lanthanides. It is therefore important to study the effect of gamma radiation on the transport behaviour of polypropylene supported liquid membrane containing Cyanex-301 as carrier. In the present work polypropylene flatsheet and Cyanex-301 solution in dodecane were irradiated separately by gamma irradiation. The transport behavior of the SLM of the irradiated polypropylene flatsheets were correlated with its change in pore structure observed by scanning electron microscopy. (author)

270

Roentgen stereophotogrammetric analysis of restricted periods of neurocranial suture immobilization in rabbits.  

Science.gov (United States)

The effect of temporary fusion of sutures on craniofacial growth was studied biometrically in 4-week-old male New Zealand White rabbits. Tantalum bone markers were implanted in the cranial vault, and the coronal suture immobilized with isobutyl-2-cyanoacrylate adhesive. Linear craniectomy was performed after 2 or 6 weeks of sutural growth restriction (four animals in each group). The animals were followed for approximately 17 weeks. Early craniectomy resulted in greatly increased coronal suture bone separation (175% of control growth rates in peers and 125% of maximal control rates). Growth after late craniectomy showed an age-dependent lower rate, but still the overshoot markedly surpassed controls (210% of control rates in peers and 65% of maximal control growth rates). Overall, both exhibited overcompensation in coronal suture growth. A rapid compensation of adjacent sutures to temporary growth restriction and a tendency toward spontaneous correction following release of growth inhibition were demonstrated. Thus, the total anteroposterior growth of the combined frontonasal and coronal sutures nearly equaled that of control animals. Following linear craniectomy, volumetric calvarial expansion increased considerably in both early and late groups, due to compensatory coronal suture growth, but probably due also to spatial bone rearrangements. Based upon the findings, the length of the suture immobilization period seems critical to longitudinal and volumetric growth as well as to subsequent compensatory activity after surgical correction. PMID:6689711

Alberius, P; Selvik, G

1984-01-01

271

Intestinal obstruction following use of laparoscopic barbed suture: a new complication with new material?  

Science.gov (United States)

Small bowel obstruction is a common pathology. Among the various etiologies, foreign material has been incriminated as a possible but uncommon cause. Recently, barbed suture has been successfully introduced in various surgical fields and has been reported as safe as standard suture. We report herein a case of intestinal obstruction due to the laparoscopic use of barbed suture during a promontofixation. Barbed suture has the risk of entrapping the small bowel. The surgeon should keep in mind this hypothetical problem and a high index of suspicion is needed to diagnose and treat quickly this potentially severe complication. PMID:22145693

Buchs, Nicolas C; Ostermann, Sandrine; Hauser, Johannes; Roche, Bruno; Iselin, Christophe E; Morel, Philippe

2012-09-01

272

Cystoscopic suture removal by Holmium-YAG laser after Burch procedure  

Directory of Open Access Journals (Sweden)

Full Text Available Burch colposuspension remains one of the successful operations performed for stress incontinence. Accidental suturing of the bladder wall during the procedure or subsequent erosion may lead to lower urinary tract symptoms. Diagnosis and management of these sutures indicate precise evaluation for which a 70 degree cystoscope is used. In selected cases, Holmium-YAG laser may enable us to manage long-standing, encrustated neglected sutures. Here we would like to report successful removal of intravesical sutures using the Holmium-YAG laser.

?skender Ba?er

2011-03-01

273

Cystoscopic suture removal by Holmium-YAG laser after Burch procedure  

Science.gov (United States)

Burch colposuspension remains one of the successful operations performed for stress incontinence. Accidental suturing of the bladder wall during the procedure or subsequent erosion may lead to lower urinary tract symptoms. Diagnosis and management of these sutures indicate precise evaluation for which a 70 degree cystoscope is used. In selected cases, Holmium-YAG laser may enable us to manage long-standing, encrustated neglected sutures. Here we would like to report successful removal of intravesical sutures using the Holmium-YAG laser. PMID:24591960

Kara?ahin, Emre Kaz?m; Esin, Sertaç; Alanbay, ?brahim; Ercan, Mutlu Cihangir; Mutlu, Erol; Ba?er, ?skender; Basal, ?eref

2011-01-01

274

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

275

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

276

Pull-string technique for recovering subconjunctival short-tag noose adjustable sutures.  

Science.gov (United States)

The "short tag noose" technique is used to adjust sutures after strabismus surgery. The pole and noose sutures are buried below conjunctiva for possible use in later adjustment; however, they are not always easily recoverable. We report a "pull string" modification of the technique that permits retrieval of the pole and noose sutures without the need to enlarge the conjunctival wound or explore the subconjunctival space. If suture adjustment proves unnecessary, the pull string can be removed effortlessly under topical anesthesia, even in uncooperative children. PMID:25448142

Tsai, Chong-Bin

2014-12-01

277

Use of a new device for endoscopic suturing in the laparoscopic Burch procedure.  

Science.gov (United States)

An innovation in surgical instrumentation for performing endoscopic suturing was applied in 15 patients who underwent a laparoscopic approach to the traditional retropubic modified Burch procedure. PMID:9050535

Gunn, G C; Cooper, R P; Gordon, N S; Gagnon, L

1994-11-01

278

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

DEFF Research Database (Denmark)

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

Thorstad, Eva B.; Økland, Finn

2013-01-01

279

Arthroscopic Posterior Stabilization of the Shoulder Using a Percutaneous Knotless Mattress Suture Technique.  

Science.gov (United States)

Posterior shoulder instability is far less common than anterior instability, and its arthroscopic treatment can be technically demanding. We describe a percutaneous arthroscopic technique for posterior shoulder stabilization using mattress sutures and knotless anchors. Spinal needles are used to pass the sutures percutaneously in a mattress fashion. Knotless anchors are used to secure the sutures under the labrum. These anchors can be used without cannulas, giving easier access to the posterior glenoid. This procedure is simple, cost-effective, and safe, avoiding the presence of both knots and suture strands in contact with the humeral head. PMID:24749039

Tennent, Duncan; Concina, Chiara; Pearse, Eyiyemi

2014-02-01

280

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

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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.

Shahla Kakoei

2010-06-01

 
 
 
 
281

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.

282

Effectivity of intraoperative adjustable suture technique in horizontal strabismus  

Directory of Open Access Journals (Sweden)

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.

Ayse Gul Kocak Altintas

2013-08-01

283

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

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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 preparati...

Vogt Peter M; Rotter Robert; Lorenzen Johan; Kraemer Robert; Knobloch Karsten

2009-01-01

284

Blood flow through sutured and coupled microvascular anastomoses: a comparative computational study.  

Science.gov (United States)

This study uses computational fluid dynamics (CFD) to model blood flow through idealised sutured and coupled arterial anastomoses to investigate the affect of each technique on intravascular blood flow. Local flow phenomena are examined in detail to study characteristics that potentially initiate thrombus formation; for example, changes in velocity profile, wall shear stress (WSS), and shear strain rate (SSR). Idealised geometries of sutured and coupled anastomoses were created with dimensions identical to microvascular suture material and a commercially available coupling device using CFD software. Vessels were modelled as non-compliant 1 mm diameter ducts, and blood was simulated as a Newtonian fluid, in keeping with previous studies. All analyses were steady-state and performed on arteries. The sutured simulation revealed a reduced boundary velocity profile; high WSS; and high SSR at the suture sites. The coupled anastomosis simulation showed a small increase in maximum WSS at the anastomotic region compared to a pristine vessel, however, this was less than half that of the sutured model. The coupled vessel displayed an average WSS equivalent to a pristine vessel simulation. Taken together these observations demonstrate a theoretically more thrombogenic profile in a sutured anastomosis when compared to a coupled vessel. Data from simulations on a coupled anastomosis reveal a profile that is nearly equivalent to that of a pristine vessel. Based purely on the combination of less favourable flow properties shown using these idealised arterial models, the sutured method is potentially more thrombogenic than a coupled anastomosis. PMID:24731801

Wain, Richard A J; Whitty, Justin P M; Dalal, Milind D; Holmes, Michael C; Ahmed, Waqar

2014-07-01

285

The Roman Bridge: a "double pulley – suture bridges" technique for rotator cuff repair  

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Full Text Available Abstract Background With advances in arthroscopic surgery, many techniques have been developed to increase the tendon-bone contact area, reconstituting a more anatomic configuration of the rotator cuff footprint and providing a better environment for tendon healing. Methods We present an arthroscopic rotator cuff repair technique which uses suture bridges to optimize rotator cuff tendon-footprint contact area and mean pressure. Results Two medial row 5.5-mm Bio-Corkscrew suture anchors (Arthrex, Naples, FL, which are double-loaded with No. 2 FiberWire sutures (Arthrex, Naples, FL, are placed in the medial aspect of the footprint. Two suture limbs from a single suture are both passed through a single point in the rotator cuff. This is performed for both anchors. The medial row sutures are tied using the double pulley technique. A suture limb is retrieved from each of the medial anchors through the lateral portal, and manually tied as a six-throw surgeon's knot over a metal rod. The two free suture limbs are pulled to transport the knot over the top of the tendon bridge. Then the two free suture limbs that were used to pull the knot down are tied. The end of the sutures are cut. The same double pulley technique is repeated for the other two suture limbs from the two medial anchors, but the two free suture limbs are used to produce suture bridges over the tendon, by means of a Pushlock (Arthrex, Naples, FL, placed 1 cm distal to the lateral edge of the footprint. Conclusion This technique maximizes the advantages of two techniques. On the one hand, the double pulley technique provides an extremely secure fixation in the medial aspect of the footprint. On the other hand, the suture bridges allow to improve pressurized contact area and mean footprint pressure. In this way, the bony footprint in not compromised by the distal-lateral fixation, and it is thus possible to share the load between fixation points. This maximizes the strength of the repair and provides a barrier preventing penetration of synovial fluid into the healing area of tendon and bone.

Maffulli Nicola

2007-12-01

286

Pubovaginal sling with a low-cost polypropylene mesh  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

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

2007-10-01

287

GC-MS OF POLYETHYLENE AND POLYPROPYLENE THERMAL CRACKING PRODUCTS  

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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.

Martin Bajus

2006-03-01

288

Conversion of atactic polypropylene waste to fuel oil. Final report  

Energy Technology Data Exchange (ETDEWEB)

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.

Bhatia, J.

1981-04-01

289

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 relapsessty, 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)

290

Influence of gamma irradiation on carbon nanotube-reinforced polypropylene.  

Science.gov (United States)

Single walled carbon nanotubes (SWNT) have been incorporated into a polypropylene (PP) matrix in different concentrations (range: 0.25-2.5 wt%). The nanotubes were blended with PP particles (approximately 500 microm in size) before mixing in an extruder. Finally, rectangular plates were obtained by compression moulding. PP-SWNT composites were gamma irradiated at different doses, 10 and 20 kGy, to promote crosslinking in the matrix and potentially enhance the interaction between nanotubes and PP. Extensive thermal, structural and mechanical characterization was conducted by means of DSC, X-ray diffraction, Raman spectroscopy, uniaxial tensile tests and dynamic mechanical thermal (DMTA) techniques. DSC thermograms reflected higher crystallinity with increasing nanotube concentration. XRD analysis confirmed the only presence of a monoclinic crystals and proved unambiguously that CNTs generated a preferred orientation. Raman spectroscopy confirmed that the intercalation of the polymer between bundles is favored at low CNTs contents. Elastic modulus results confirmed the reinforcement of the polypropylene matrix with increasing SWNT concentration, although stiffness saturation was observed at the highest concentration. Loss tangent DMTA curves showed three transitions for raw polypropylene. While gamma relaxation remained practically unchanged in all the samples, beta relaxation temperatures showed an increase with increasing CNT content due to the reduced mobility of the system. Gamma-irradiated PP exhibited an increase in the beta relaxation temperature, associated with changes in glass transition due to radiation-induced crosslinking. On the contrary, gamma-irradiated nanocomposites did not show this effect probably due to the reaction of radiative free radicals with CNTs. PMID:19908494

Castell, P; Medel, F J; Martinez, M T; Puértolas, J A

2009-10-01

291

Nonabsorbable-suture-induced osteomyelitis: a case report and review of the literature.  

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We are reporting a case of nonabsorbable suture-induced osteomyelitis in patient who had an open rotator cuff repair with nonabsorbable Ethibond anchor suture. Patient in this case presented with very subtle clinical features of osteomyelitis of the left proximal humerus 15 years after initial rotator cuff repair surgery. Literature had shown that deep infection following rotator cuff repairs, although rare, can be easily missed and can cause severe complications. Absorbable suture had been demonstrated to be more superior, in terms of rate of deep infection, as compared to nonabsorbable suture when used in rotator cuff repair surgery. Both absorbable and nonabsorbable suture had been demonstrated to have similar mechanical properties by several different studies. The case demonstrated that initial presentation of deep infection can be subtle and easily missed by clinicians and leads to further complications. PMID:23259121

Yeo, Cheng Hong; Russell, Nick C; Sharpe, Tom

2012-01-01

292

Suture passing needle breakage during arthroscopic rotator cuff repair: a complication report.  

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Arthroscopic rotator cuff repair is a well established surgical technique. Passing sutures through the rotator cuff is a critical-and at times, time-consuming-portion of the procedure. Suture-passing devices have been developed that combine a nitinol needle for pushing sutures through the tissue with a tissue grasper. These devices eliminate multiple steps in the repair process and improve the efficiency of the operation. However, as with any innovation, there is the potential for complications. It is vital that these technical complications be appreciated so that they can be avoided in the future. We report a case in which the needle tip of a suture-passing device broke during arthroscopic rotator cuff repair. The breakage was not recognized until after the operation. The patient was observed for 2 years without migration of the foreign body. To our knowledge, this is the first reported complication associated with the use of this type of suturing device. PMID:19038716

Song, Hyun Seok; Ramsey, Matthew L

2008-12-01

293

Mechanical and morphological characterization of polypropylene toughened with olefinic elastomer  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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 (

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

2000-04-01

294

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.)

295

Synthesis of Flame-Retardant Polypropylene/LDH-Borate Nanocomposites  

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New nanocomposites have been prepared using unmodified polypropylene (PP) and a new type of highly dispersed [Zn2Al(OH6)][B 4O5(OH)4]0.5 (Zn2Al- borate) and [Mg3Al(OH)8][B4O 5(OH)4]0.5 (Mg3Al-borate) layered double hydroxides (LDHs). PP/LDHs nanocomposites with LDH loadings of 1, 3, 6, 9, 15, and 30 wt % have been prepared by a novel solvent mixing method. Scanning electron microscopy (SEM) analysis shows that the precipitated nanocomposites materials form spherical particles with an average ...

Wang, Q.; Undrell, Jp; Gao, Y.; Cai, G.; Buffet, J-c; Wilkie, Ca; O Hare, D.

2013-01-01

296

Polypropylene/organoclay/SEBS nanocomposites with toughness-stiffness properties  

DEFF Research Database (Denmark)

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.

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

2014-01-01

297

Surface modifications of polypropylene by high energy carbon ions  

International Nuclear Information System (INIS)

Polypropylene was irradiated with 12C ions of 3.6 and 5.4 MeV energies using 3 MV tandem accelerator. The surface modification was investigated by Scanning Electron Microscopy (SEM). Optical changes were monitored by UV-VIS and FTIR spectroscopy. At the lowest ion fluence, only blister formation of various sizes (1-6 ?m) was observed. Polymer when irradiated at a fluence of 1x1014 ions/cm2 exhibited a network structure. A comparative study on dose dependence of surface and bulk modification has been described. (author)

298

Polypropylene-polyethylene blends modified by gamma radiation  

International Nuclear Information System (INIS)

One way to obtain a better mechanical property of polypropylene and polyethylene is to increasing the number of polymer chains cross-linked by gamma radiation. After irradiation a network is formed as a result of various chemical reactions and the radicals formed are concentrated in the amorphous phase. With the objective to improve the mechanical properties of PP, blends with PE were prepared and irradiated in doses up to 500 kGy, in atmospheric ambient. The molecular characterization of the blends was made by infrared spectroscopy and the data showed an increase in rigidity and a unique behaviour in Izod impact resistance. (author)

299

Cementitious composites reinforced with polypropylene, nylon and polyacrylonitile fibres  

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This paper compares the adhesion strength between three polymeric fibres (polypropylene (PP), nylon66 (N66) and polyacrylonitrile (PAN)) embedded in a cement paste. The specimens were prepared at a water to cement ratio (w/c) of 0.5, and tested after 7, 14 and 28 curing days. It was found that although the adhesion between the polymeric fibres to the cement matrix is an important factor, the energy absorption capacity or energy dissipation ability of the fibres plays a more important...

Pakravan, H. R.; Jamshidi, M.; Latifi, M.; Torgal, Fernando Pacheco

2011-01-01

300

Properties of Reactive Compatibilized Dika Nutshell Powder filled Recycled Polypropylene (PP)/Polyethylene Terephthalate (PET) Biocomposites using Maleated Polypropylene and Epoxy Resin Dual Compatibilizers  

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Dika nutshell powder (DNS) filled – recycled polypropylene (PP)/polyethylene terephthalate (PET) biocomposite was prepared by reactive compatibilization using maleic anhydride-grafted-polypropylene (MAPP) and epoxy resin (EPR) as dual compatibilizers. The mechanical and rheological properties, as well as sorption behavior of the compatibilized biocomposites were studied at filler loadings of 0, 2, 4, 6, 8, and 10 phr (parts per hundred parts of resin). PP/PET composition was fixed at 30/70 ...

Onyeagoro, G. N.

2013-01-01

 
 
 
 
301

Effect of disagreement between refractive, keratometric, and topographic determination of astigmatic axis on suture removal after penetrating keratoplasty  

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BACKGROUND/AIMS—Post-keratoplasty astigmatism can be managed by selective suture removal in the steep axis. Corneal topography, keratometry, and refraction are used to determine the steep axis for suture removal. However, often there is a disagreement between the topographically determined steep axis and sutures to be removed and that determined by keratometry and refraction. The purpose of this study was to evaluate any difference in the effect of suture removal, on visual acuity and astig...

Sarhan, A.; Dua, H.; Beach, M.

2000-01-01

302

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

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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.

Nascimento Luiz Roberto do

1999-01-01

303

Biomechanical evaluation of suture-holding properties of native and tissue-engineered articular cartilage.  

Science.gov (United States)

The purpose of this study was to determine suture-holding properties of tissue-engineered neocartilage relative to native articular cartilage. To this end, suture pull-out strength was quantified for native articular cartilage and for neocartilages possessing various mechanical properties. Suture-holding properties were examined in vitro and in vivo. Neocartilage from bovine chondrocytes was engineered using two sets of exogenous stimuli, resulting in neotissue of different biochemical compositions. Compressive and tensile properties and glycosaminoglycan, collagen, and pyridinoline cross-link contents were assayed (study 1). Suture pull-out strength was compared between neocartilage constructs, and bovine and leporine native cartilage. Uniaxial pull-out test until failure was performed after passing 6-0 Vicryl through each tissue (study 2). Subsequently, neocartilage was implanted into a rabbit model to examine short-term suture-holding ability in vivo (study 3). Neocartilage glycosaminoglycan and collagen content per wet weight reached [Formula: see text] and [Formula: see text], respectively. Tensile properties for neocartilage constructs reached [Formula: see text] MPa for Young's modulus and [Formula: see text] MPa for ultimate tensile strength. Neocartilage reached [Formula: see text]33 % of suture pull-out strength of native articular cartilage. Neocartilage cross-link content reached 50 % of native values, and suture pull-out strength correlated positively with cross-link content [Formula: see text]. Neocartilage sutured into rabbit osteochondral defects was successfully maintained for 3 weeks. This study shows that pyridinoline cross-links in neocartilage may be vital in controlling suture pull-out strength. Neocartilage produced in vitro with one-third of native tissue pull-out strength appears sufficient for construct suturing and retention in vivo. PMID:24848644

DuRaine, G D; Arzi, B; Lee, J K; Lee, C A; Responte, D J; Hu, J C; Athanasiou, K A

2015-01-01

304

Absorbable Versus Silk Sutures for Surgical Treatment of Trachomatous Trichiasis in Ethiopia: A Randomised Controlled Trial  

Science.gov (United States)

Background Trachoma causes blindness through an anatomical abnormality called trichiasis (lashes touching the eye). Trichiasis can recur after corrective surgery. We tested the hypothesis that using absorbable sutures instead of silk sutures might reduce the risk of recurrent disease among patients with major trichiasis in a randomised trial. Methods and Findings 1,300 individuals with major trichiasis from rural villages in the Amhara Region of Ethiopia were recruited and assigned (1?1) by computer-generated randomisation sequence to receive trichiasis surgery using either an absorbable suture (polyglactin-910) or silk sutures (removed at 7–10 days) in an otherwise identical surgical technique. Participants were examined every 6 months for 2 years by clinicians masked to allocation. The primary outcome measure was recurrent trichiasis (?one lash touching the eye) at 1 year. There was no difference in prevalence of recurrent trichiasis at 1 year (114 [18.2%] in the absorbable suture group versus 120 [19.7%] in the silk suture group; odds ratio?=?0.90, 95% CI 0.68–1.20). The two groups also did not differ in terms of corneal opacification, visual acuity, conjunctival inflammation, and surgical complications. Conclusions There was no evidence that use of absorbable polyglactin-910 sutures was associated with a lower prevalence of trichiasis recurrence at 1 year postsurgery than silk sutures. However, from a programmatic perspective, polyglactin-910 offers the major advantage that patients do not have to be seen soon after surgery for suture removal. The postoperative review after surgery using absorbable polyglactin-910 sutures can be delayed for 3–6 months, which might allow us to better determine whether a patient needs additional surgery. Trial registration ClinicalTrials.gov NCT00522860 Please see later in the article for the Editors' Summary PMID:22180732

Rajak, Saul N.; Habtamu, Esmael; Weiss, Helen A.; Kello, Amir Bedri; Gebre, Teshome; Genet, Asrat; Bailey, Robin L.; Mabey, David C. W.; Khaw, Peng T.; Gilbert, Clare E.; Emerson, Paul M.; Burton, Matthew J.

2011-01-01

305

Transcutaneous Serdev Suture For Buttock’s Lift  

Directory of Open Access Journals (Sweden)

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".

Nikolay Serdev

2013-10-01

306

Celastrol nanoparticles inhibit corneal neovascularization induced by suturing in rats  

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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

Li ZR

2012-03-01

307

Single-incision laparoscopic splenectomy with innovative gastric traction suture  

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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.

Srikanth G

2011-01-01

308

Air gasification of polypropylene plastic waste in fluidized bed gasifier  

International Nuclear Information System (INIS)

An experimental study on air gasification of polypropylene was conducted in a fluidized bed gasifier with an insider diameter (i.d.) of 100 mm and a height of 4.2 m. The effect of the equivalence ratio, bed height and fluidization velocity on various gasification results, including the product yield distribution, gas composition, gas heating value and gas yield were studied. The equivalence ratio appeared to have a significant effect on the reactor temperature and other gasification results. The increase of the equivalence ratio favored the formation of the fuel gas and decreased the formation of the tars and char. The decrease in the hydrocarbons content and, therefore, the gas heating value with an increase in the equivalence ratio were also observed. Both the bed height and the fluidization velocity seemed to have a small influence on the gasification results. The results obtained so far indicated that fluidized bed gasification of polypropylene with air could produce a fuel gas with a calorific value in the range of 5.2-11.4 MJ/N m3 and low tars content, which could be used in many end use applications

309

Preparation and Characterization of Coir, Luffa Reinforced Polypropylene Composites  

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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.

S.Tharaknath

2014-10-01

310

Improvement of printability and adhesion of polypropylene films by radiation  

International Nuclear Information System (INIS)

Polyethylene and polypropylene are widely used, but have the demerits that the printing and adhesion by ordinary methods are difficult. Generally those are improved by corona discharge treatment, but it is still insufficient. Therefore, the reforming by radiation was attempted by using polypropylene films. The reforming was carried out by the methods of the graft polymerization of acrylic acid by gamma ray, low energy electron beam, plasma processing and spray method using low energy electron beam, and by coating the mixture of monomer and oligomer and hardening by low energy electron beam. The separation strength (adhesion) from Scotch tapes and the printability by cross cut separation method of the reformed films were measured. In the graft polymerization methods, for obtaining the graft ratio of several %, the reaction time of several tens minutes was required. By the spray method and coating method, the adhesion was increased to about three times as high as that of the samples without irradiation. Printing is feasible in the reformed films, but those by the spray method are not suitable to fine printing because of surface unevenness. The continuous process mainly using the spray method was tested, and the reformed film of several tens m was made. The results are reported. (K.I.)

311

Chemical modification of polypropylene induced by high energy carbon ions  

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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

312

Morphology and properties of recycled polypropylene/bamboo fibers composites  

International Nuclear Information System (INIS)

Polypropylene (PP) is among the most widely used thermoplastics in many industrial fields. However, like other recycled polymers, its properties usually decrease after recycling process and sometimes are degraded to poor properties level for direct re-employment. The recycled products, in general, need to be reinforced to have competitive properties. Short bamboo fibers (BF) have been added in a recycled PP (RPP) with and without compatibilizer type maleic anhydride polypropylene (MAPP). Several properties of composite materials, such as helium gas permeability and mechanical properties before and after ageing in water, were examined. The effects of bamboo fiber content and fiber chemical treatment have been also investigated. We showed that the helium permeability increases if fiber content is higher than 30% because of a poor adhesion between untreated bamboo fiber and polymer matrix. The composites reinforced by acetylated bamboo fibers show better helium permeability due to grafting of acetyl groups onto cellulose fibers surface and thus improves compatibility between bamboo fibers and matrix, which has been shown by microscopic observations. Besides, mechanical properties of composite decrease with ageing in water but the effect is less pronounced with low bamboo fiber content.

313

Investigation of Fibres Migration in Cotton/Polypropylene Blended Yarn  

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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

Dzmitry RYKLIN

2014-09-01

314

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.

315

Formability of Aluminum 5182-Polypropylene Sandwich Sheet for Automotive Application  

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The AA5182/polypropylene/AA5182 (AA/PP/AA) sandwich sheet is the material fabricated by adhering two aluminum skins to one polypropylene core. When it has the same flexural rigidity as a steel sheet, it is 65% lighter than the steel sheet and 30% lighter than an aluminum alloy sheet. Therefore, it is notified exclusively as good substitutive materials for a steel body to improve the fuel efficiency. Through AA/PP/AA sandwich sheet, however, it has relatively lower formability than that of the steel sheet for automotive application. In this study, we developed formability evaluation techniques in order to apply AA/PP/AA sandwich sheet for an automotive parts. For this purpose, newly adopting formability evaluations (using limit dome height and plane strain test) were carried out in order to secure the fundamental data for the measurement of sheet metal forming and the establishment of optimum forming conditions of the sandwich sheet. The results showed that there were in good agreements between the old formability evaluation method and the new one which was more simplified than that of the old one. From the results of these formability evaluations, the formability of sandwich sheet was higher than that of aluminum alloy sheet alone which was the skin component for the sandwich sheet. In addition, it was found that sandwich sheet could reduce the weight and could have the same flexural rigidity simultaneously when it was compared to the automotive steel sheet.

Kim, Kee Joo; Kim, Cheol-Woong; Choi, Byung-Ik; Sung, Chang Won; Kim, Heon Young; Won, Si-Tae; Ryu, Ho-Yeun

316

Morphology and properties of recycled polypropylene/bamboo fibers composites  

Science.gov (United States)

Polypropylene (PP) is among the most widely used thermoplastics in many industrial fields. However, like other recycled polymers, its properties usually decrease after recycling process and sometimes are degraded to poor properties level for direct re-employment. The recycled products, in general, need to be reinforced to have competitive properties. Short bamboo fibers (BF) have been added in a recycled PP (RPP) with and without compatibilizer type maleic anhydride polypropylene (MAPP). Several properties of composite materials, such as helium gas permeability and mechanical properties before and after ageing in water, were examined. The effects of bamboo fiber content and fiber chemical treatment have been also investigated. We showed that the helium permeability increases if fiber content is higher than 30% because of a poor adhesion between untreated bamboo fiber and polymer matrix. The composites reinforced by acetylated bamboo fibers show better helium permeability due to grafting of acetyl groups onto cellulose fibers surface and thus improves compatibility between bamboo fibers and matrix, which has been shown by microscopic observations. Besides, mechanical properties of composite decrease with ageing in water but the effect is less pronounced with low bamboo fiber content.

Phuong, Nguyen Tri; chuong, Bui; Guinault, Alain; Sollogoub, Cyrille

2011-05-01

317

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)

318

Effectiveness of ultrasonographic evaluation of the cranial sutures in children with suspected craniosynostosis  

International Nuclear Information System (INIS)

Computed tomography (CT) is the 'gold standard' for evaluation of the cranial sutures. While prenatal cranial suture evaluation with ultrasound (US) is common, US has not been established as a postnatal screening tool. We evaluated the effectiveness of US for diagnosis of craniosynostosis (CS). During 2006, 24 infants with questionable CS were assessed with US of the sagittal, metopic, and bilateral coronal and lambdoid sutures. US findings and clinical records were reviewed retrospectively. Sixteen boys and eight girls (ages 1-11 months, mean 4.3) underwent US. The correct diagnosis was provided in 23 (95%), with equivocal findings in one patient. Cranial sutures appeared normal in 15 infants, who had normal clinical presentation at mean 5.8 months follow-up; CT confirmation was obtained in two. In eight children, US identified premature closure of one or more cranial sutures. Three-dimensional CT was performed as a preparation for surgery in four, with classical CS findings. In one case with inconclusive US findings, CT showed narrow but open sutures. Sonographic examination of cranial sutures may serve as a first imaging tool for evaluation of craniosynostosis. CT may be reserved for children with abnormal or equivocal ultrasound and for preoperative planning. (orig.)

319

Effectiveness of ultrasonographic evaluation of the cranial sutures in children with suspected craniosynostosis  

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Computed tomography (CT) is the 'gold standard' for evaluation of the cranial sutures. While prenatal cranial suture evaluation with ultrasound (US) is common, US has not been established as a postnatal screening tool. We evaluated the effectiveness of US for diagnosis of craniosynostosis (CS). During 2006, 24 infants with questionable CS were assessed with US of the sagittal, metopic, and bilateral coronal and lambdoid sutures. US findings and clinical records were reviewed retrospectively. Sixteen boys and eight girls (ages 1-11 months, mean 4.3) underwent US. The correct diagnosis was provided in 23 (95%), with equivocal findings in one patient. Cranial sutures appeared normal in 15 infants, who had normal clinical presentation at mean 5.8 months follow-up; CT confirmation was obtained in two. In eight children, US identified premature closure of one or more cranial sutures. Three-dimensional CT was performed as a preparation for surgery in four, with classical CS findings. In one case with inconclusive US findings, CT showed narrow but open sutures. Sonographic examination of cranial sutures may serve as a first imaging tool for evaluation of craniosynostosis. CT may be reserved for children with abnormal or equivocal ultrasound and for preoperative planning. (orig.)

Simanovsky, Natalia; Hiller, Nurith; Koplewitz, Benjamin; Rozovsky, Katya [Hadassah Hebrew University Medical Center, Department of Medical Imaging, Mount, Scopus, P.O. Box 24035, Jerusalem (Israel)

2009-03-15

320

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

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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

Mevci Özdemir

2014-09-01

 
 
 
 
321

Comparison of polydioxanone (PDS and polyamid (nylon sutures complications in abdominal midline repair (laparotomy surgery  

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Full Text Available Background and purpose: Despite progresss in the techniques of surgery, there is still a lot of controversy about selection of the best technique and suture material. Many post operation complications such as infection, wound dehiscence, pain and sinus formation are related to the type of the suture used. In this study we compared the complications due to the absorbent suture (PDS with a non absorbent suture (nylon in laparotomy operation.Materials and Methods: This clinical trial was performed on 120 patients referring to Imam Khomeini hospital, Sari, 2003-2005 for laparotomy. They were randomly divided in tow groups of equal number. The incision was repaired with PDS sutures in case and with nylon suture in control group. All patients under study were followed up for one year. Data about chronic pain,wound dehiscence, infection, hernia and sinus formation were recorded and analyzed using SPSS software and Chi- square test.Results: In this study 120 patients (60 in case and 60 in control groups were enrolled. After laparotomy, the incidence of chronic pain and sinus formation in case group was significantly less than the control group. There were no significant differences between the rate of infection, hernia and wound dehiscence in the two groups.Conclusion: No significant differences in the rate of infection, hernia and wound dehiscence between two types of suture materials were observed. However, application of PDS leads to less pain and sinus formation. Therefore, it can be a better choice in surgical incisions.

F.Eshghi

2006-01-01

322

Immunostimulatory sutures that treat local disease recurrence following primary tumor resection  

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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)

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

323

The role of graft materials in suture augmentation for tendon repairs and reattachment.  

Science.gov (United States)

Various biomaterials have been used to augment sutures for the repair and reattachment of tendons. This study examined four different graft materials in a simple and reproducible model using chicken Achilles tendons to determine the strength and mechanism of suture reinforcement of tendon repairs. The graft materials tested were Gore-Tex(R) Soft Tissue Patch, Graftjacket, bovine pericardium, and an experimental graft material from Xylos Corporation. Testing was performed in shear to simulate forces on a torn tendon repair and pull-off to simulate those on a tendon reattachment to bone. Compared to unaugmented suture, grafts increased suture fixation strength from 10% to 60% in shear and from 0% to 36% in pull-off with the bovine pericardium graft, providing significant improvement in both tests. In no cases (even unaugmented) did the suture pull directly through the tendon, but instead sliced along it, demonstrating that the interface between the suture and the tendon determines fixation strength. Grafts function by increasing the area, friction, and nature of this interface, not by acting as a barrier for suture pull-through. PMID:15981174

Kummer, Frederick J; Iesaka, Kazuho

2005-08-01

324

Development of silver nano-coatings on silk sutures as a novel approach against surgical infections.  

Science.gov (United States)

The infections give rise to a range of clinical problems and prolong hospitalization with increased healthcare costs. Moreover, persistent infections exasperate the problem of antibiotic resistance. The aim of this study was the development of effective and low-cost antibacterial silver coatings on surgical sutures by adopting an innovative photochemical deposition process to prevent early contamination of surgical wounds. The silver deposition technology adopted in this work is an innovative process based on the in situ photoreduction of a silver solution. The samples were dipped in the silver solution and then exposed to UV radiation in order to induce the synthesis of silver clusters on the surface of the suture. The homogeneous distribution of silver particles on the surface and on the cross-section of the treated sutures was demonstrated. All the antibacterial studies clearly demonstrated that the use of novel silver treated sutures could represent clinical advantages in terms of the prevention of surgical infections against bacterial colonization. The silver coating deposited on the sutures demonstrated no cytotoxic effect on a selected cell population. The results obtained suggested that the antibacterial silver-coated sutures developed in this work could represent an interesting alternative to conventional sutures, with evident advantages in terms of prevention of the surgical infections and on the health costs. In addiction, very low concentrations of silver significantly inhibited the microbial load, without affecting the cell viability. PMID:24997984

De Simone, S; Gallo, A L; Paladini, F; Sannino, A; Pollini, M

2014-09-01

325

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 certh are abnormal. Our results provide certain basic information about skull base maturity in children. (author)

326

Mechanical Properties of Cranial Bones and Sutures in 1–2-Year-Old Infants  

Science.gov (United States)

Background The mechanical properties of 1–2-year-old pediatric cranial bones and sutures and their influential factors were studied to better understand how the pediatric calvarium reacts to loading. Material/Methods Cranial bone and suture specimens were extracted from seven fresh-frozen human infant cadavers (1.5±0.5 years old). Eight specimens were obtained from each subject: two frontal bones, two parietal bones, two sagittal suture samples, and two coronal suture samples. The specimens were tested in a three-point bend setup at 1.5 mm/s. The mechanical properties, such as ultimate stress, elastic modulus, and ultimate strain, were calculated for each specimen. Results The ultimate stress and elastic modulus of the frontal bone were higher than those of the parietal bone (P0.05). The ultimate stress and elastic modulus of the frontal and parietal bones were higher than those of the sagittal and coronal sutures (P<0.05), whereas the opposite ultimate strain findings were revealed (P<0.05). Conclusions There was no significant difference in ultimate stress, elastic modulus, or ultimate strain between the sagittal and coronal sutures. However, there were significant differences in ultimate stress, elastic modulus, and ultimate strain between the frontal and parietal bones as well as between the cranial bones and sutures. PMID:25279966

Wang, Jiawen; Zou, Donghua; Li, Zhengdong; Huang, Ping; Li, Dongri; Shao, Yu; Wang, Huijun; Chen, Yijiu

2014-01-01

327

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.)

328

Susceptibility to scratch surface damage of wollastonite- and talc-containing polypropylene micrometric composites  

Energy Technology Data Exchange (ETDEWEB)

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.

Hadal, R.; Dasari, A.; Rohrmann, J.; Misra, R.D.K

2004-08-25

329

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.

330

Ameloblastin inhibits cranial suture closure by modulating MSX2 expression and proliferation.  

Science.gov (United States)

Deformities of cranial sutures such as craniosynostosis and enlarged parietal foramina greatly impact human development and quality of life. Here we have examined the role of the extracellular matrix protein ameloblastin (Ambn), a recent addition to the family of non-collagenous extracellular bone matrix proteins, in craniofacial bone development and suture formation. Using RT-PCR, western blot and immunohistochemistry, Ambn was localized in mouse calvarial bone and adjacent condensed mesenchyme. Five-fold Ambn overexpression in a K14-driven transgenic mouse model resulted in delayed posterior frontal suture fusion and incomplete suture closure. Moreover, Ambn overexpressor skulls weighed 13.2% less, their interfrontal bones were 35.3% thinner, and the width between frontal bones plus interfrontal suture was 14.3% wider. Ambn overexpressing mice also featured reduced cell proliferation in suture blastemas and in mesenchymal cells from posterior frontal sutures. There was a more than 2-fold reduction of Msx2 in Ambn overexpressing calvariae and suture mesenchymal cells, and this effect was inversely proportionate to the level of Ambn overexpression in different cell lines. The reduction of Msx2 expression as a result of Ambn overexpression was further enhanced in the presence of the MEK/ERK pathway inhibitor O126. Finally, Ambn overexpression significantly reduced Msx2 down-stream target gene expression levels, including osteogenic transcription factors Runx2 and Osx, the bone matrix proteins Ibsp, ColI, Ocn and Opn, and the cell cycle-related gene CcnD1. Together, these data suggest that Ambn plays a crucial role in the regulation of cranial bone growth and suture closure via Msx 2 suppression and proliferation inhibition. PMID:23593111

Atsawasuwan, Phimon; Lu, Xuanyu; Ito, Yoshihiro; Zhang, Youbin; Evans, Carla A; Luan, Xianghong

2013-01-01

331

B-Lynch suture technique to control postpartum hemorrhage in a patient with mullerian anomaly  

Directory of Open Access Journals (Sweden)

Full Text Available Congenital anomalies of the uterus may cause gynecologic, obstetric and fertility problems. Obstetrical complications are reported to occur more commonly with mullerian duct anomalies, such as postpartum hemorrhage (PPH. Uterine compression sutures may be effective in controlling PPH in these conditions as an alternative to hysterectomy, especially if the patient has a desire to conceive. As the shape of the uterus is changed in congenital malformation, the usage of compression sutures such as B-Lynch can be more difficult. In this study we report a case of PPH accompanying a large septae, treated with B-Lynch suture. A 24 year old, multigravid and nulliparous patient (G:3 was admitted to our clinic with vaginal bleeding and abdominal pain at 31 weeks of gestation. Emergency cesarean section was performed for abruptio placenta and PPH occurred subsequently. A deep uterine septum was revealed during operation. Intermittent fundal massage and intravenous uterotonics were used to improve uterine tonicity without any improvement. After the B-Lynch suture was performed, the bleeding diminished dramatically. As the shape of the uterus is changed in congenital malformation, the application of secondary interventions in postpartum hemorrhage can be more difficult. There can be slippage or overlapping of the suture while using a B-Lynch suture. Because the uterine shape is not completely distorted, patients with septate uterus can be candidates for a B-Lynch suture. There is no such reported case from the literature regarding efficacy of B-Lynch suture in mullerian anomalies. his case illustrates the potential benefits of B-Lynch compression suture in an uterus with mullerian anomalies.

Mehmet Vural

2011-03-01

332

Complement activation by vascular sutures both alone and in combination with synthetic vascular prostheses.  

Science.gov (United States)

Polymer surfaces activate complement pathways resulting in platelet and leucocyte deposition as well as possible release of growth factors. A consequence of these interactions may be early graft failure or intimal hyperplasia leading to late graft failure. C5a generation in human plasma by vascular sutures, both alone and in combination with synthetic vascular prostheses was measured by radioimmunoassay to determine the influence of suture materials on C5a activation. Prolene and ePTFE suture material caused significant activation of C5a (p less than 0.01), while Novafil did not. Both Dacron and ePTFE graft material caused significant activation (p less than 0.01) of C5a. The addition of the suture materials to the ePTFE did not increase the C5a levels above the ePTFE material alone. In contrast, the addition of either Prolene or Novafil suture to Dacron material elevated C5a levels significantly over Dacron alone (p less than 0.01). The combination of Dacron material with ePTFE suture did not increase C5a levels over Dacron alone. The pattern of C5a activation by Prolene, ePTFE and Novafil sutures parallels the relative degree of in-vivo platelet accumulation on these suture materials as previously reported by our group. Since these experiments demonstrate that vascular suture material influences human complement activation, it may be that this interaction contributes to either early or late graft failure by enhancing platelet reactivity or neointimal proliferation, respectively. PMID:1830854

Coleman, J E; McEnroe, C S; Gelfand, J A; Connolly, R J; Callow, A D

1991-06-01

333

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 icause 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.)

334

Sutura intestinal monoplano extramucosa en dos hemisurget en pacientes con operaciones abdominales / Single layer intestinal extramucosal suturing using two semi-continuous sutures in patients with abdominal surgery  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Objetivo: comparar el empleo de la sutura intestinal monoplano extramucosa en dos hemisurget con la sutura en dos planos, en pacientes con operaciones abdominales. Métodos: se realizó un estudio observacional-analítico de tipo prospectivo, de evaluación de tecnología quirúrgica, controlado, aleatori [...] zado y a simple ciegas, en 126 pacientes mayores de 15 años de edad, de ambos sexos. En 76 se empleó el método monoplano extramucosa en dos hemisurget y en 50 pacientes se utilizó el método de sutura intestinal en dos planos. Se tuvo en cuenta la frecuencia y el tipo de las complicaciones y su relación con el método de sutura empleado, así como la influencia en el tiempo quirúrgico y el tiempo de estadía hospitalaria. Resultados: con el método monoplano extramucosa en dos hemisurget, solo 13 pacientes sufrieron algún tipo de complicación; 64 pacientes (84,2 %) fueron intervenidos en un tiempo menor a las 2 h y el 80,3 % tuvo una estadía hospitalaria menor de 7 días. Las complicaciones más frecuentes en ambos grupos fueron la infección del sitito operatorio, las fístulas estercoráceas y la dehiscencia parcial de la sutura. La sutura intestinal monoplano extramucosa en dos hemisurget presentó menor frecuencia de complicaciones y una disminución considerable en el tiempo quirúrgico y la estadía hospitalaria. Conclusiones: la sutura intestinal monoplano en dos hemisurget resulta el método de elección para la sutura intestinal. Abstract in english Objective: compare the use of single layer intestinal extramucosal suturing using two semi-continuous sutures versus two-layer suturing in patients with abdominal surgery. Methods: a controlled randomized single-blind observational-analytical prospective surgical technique evaluation study was condu [...] cted with 126 patients of both sexes aged over 15. The single-layer extramucosal method using two semi-continuous sutures was used in 76 patients, and the two-layer intestinal suturing method in 50. Account was taken of the frequency and type of complications, and their relation to the suturing method used, as well as the influence upon surgical time and the length of hospital stay. Results: with the single layer extramucosal method using two semi-continuous sutures only 13 patients had complications of any sort; surgical time was under 2 h in 64 patients (84.2 %), and the length of hospital stay was under 7 days in 80.3 %. The most common complications in both groups were surgical site infection, stercoraceous fistulas and partial suture dehiscence. Single layer intestinal extramucosal suturing using two semi-continuous sutures showed a lower rate of complications and a considerable decrease in surgical time and length of hospital stay. Conclusions: single layer intestinal suturing using two semi-continuous sutures is the method of choice for intestinal suturing.

Yury, Valle Lara; Vivian, Rodríguez Tápanes.

2012-06-01

335

Delayed migration of a metal suture anchor into the glenohumeral joint.  

Science.gov (United States)

Intra-articular migration is a known complication of poorly placed metallic suture anchors in rotator cuff repair and labral reconstruction. We report a case of intra-articular migration of a metallic suture anchor seven years after open labral reconstruction. Despite the fact that the patient remained asymptomatic for seven years, presence of an extra-osseous anchor was already noted postoperatively. In an era where the use of suture anchors has become common practice, surgeons should always be aware of possible anchor migration, especially when patients complain of sudden sharp pain, persistent pain, a catching sensation and loss of mobility. PMID:21302585

Goeminne, Sofie; Debeer, Philippe

2010-12-01

336

[Review of the physical and surgical technical properties of modern monofilament suture materials].  

Science.gov (United States)

This paper documents the differences among 8 monofile sutures in important functions such as linear tensile strength, bending stiffness, knot security and irreversible elongation. The results show that two materials (Prolene and Gore-Tex) do not seem to be as suitable as the other materials for long-term tensile loads. The lowest bending stiffness was that of Seralon. The highest knot security can already be reached with three loops of Novafil. Novafil has also got the highest maximal elongation. The knowledge of the different applications of suture materials tested in important practical functions, is the supposition to the right and secure use of suture materials. PMID:3533460

Lünstedt, B; Knoop, M; Thiede, A

1986-08-01

337

Perspectives on craniosynostosis: sutural biology, some well-known syndromes, and some unusual syndromes.  

Science.gov (United States)

Perspectives on craniosynostosis are discussed under the following headings: sutural biology (anatomic and genetic categories of synostosis; sutures, suture systems, and types of craniosynostosis; well-known syndromes (Muenke syndrome and Pfeiffer syndrome); and unusual syndromes (thanatophoric dysplasia, Beare-Stevenson cutis gyrata syndrome, Crouzonodermoskeletal syndrome, Carpenter syndrome, Elejalde syndrome, hypomandibular faciocranial syndrome, and craniorhiny). Five of these syndromes are caused by fibroblast growth factor receptor (FGFR) mutations; one is caused by ras-like in rat brain 23 (RAB23) mutations; and three have Mendelian patterns of inheritance, but the molecular basis remains unknown to date. PMID:19293680

Cohen, M Michael

2009-03-01

338

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)

339

CO-PYROLYSIS OF POLYPROPYLENE WITH PETROLEUM OF BACIA DE CAMPOS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this study, the process of co-pyrolysis of polypropylene (PP) residues with gas-oil was evaluated, varying thetemperature and the amount of polypropylene fed to the reactor. The polypropylene samples and gas-oil weresubmitted to the thermal co-pyrolysis in an inert atmosphere, varying the temperature and the amount of PP.The influence of the gas-oil was evaluated carrying the co-pyrolysis in the absence of PP. The pyrolysed liquidsproduced by this thermal treatment were characterized by mo...

Assumpc?a?o, Luiz Carlos Fonte Nova Marques

2009-01-01

340

Pulse NMR-spectroscopy of structural changes of chemically modified polypropylene  

International Nuclear Information System (INIS)

The structure of polypropylene compositions is studied by the method of pulse NMR-spectroscopy. The polypropylene compositions are derived by means of the modification by multicomponent systems. The analysis of relaxation times in a wide temperature range is carried out. Character of changes going on at a level of supermolecular structures is described. It is shown that the amplifications that manifest themselves under the polypropylene modification by the mixtures based on 2,4-tolyilendiisocyanate and e-caprolactam, are related to the change in the intermolecular interaction and formation of a more ordered polymer structure. (authors)

 
 
 
 
341

Inflammatory reaction and tensile strength of the abdominal wall after an implant of polypropylene mesh and polypropylene/poliglecaprone mesh for abdominal wall defect treatment in rats  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english PURPOSE: To compare the inflammatory reaction and the growing resistance of the abdominal wall with the use of poliglecaprone meshes and polypropylene meshes associated with poliglecaprone in the correction of abdominal defects. METHODS: Seventy-seven Wistar rats were divided into three groups [...] : CG (non-operated animals: EG (polypropylene mesh) and UG (polypropylene and poliglecaprone mesh). A muscular and aponeurotic defect was formed and treated according to the group. Evaluations were made after 4, 7, 14, 28 and 56 days. The resistance and inflammatory pattern were studied. RESULTS: There was a gradual and significant gain in resistance, regularly in the EG and irregularly in the UG, which was lower on the 14th day (p=0.008). The inflammatory reaction was acute and more intense in the UG on the fourth day. At all other times, the inflammatory pattern was acute to chronic, similar in both groups, with minimum intensity on the 56th day. CONCLUSION: The greater resistance offered by the polypropylene mesh was regular and ascending, stabilizing on the 28th day, while that of the polypropylene/poliglecaprone was not even. In the end, the resistances were similar. The inflammatory response was greater in the UG on the fourth day and similar at all other times.

Maria de Lourdes Pessole, Biondo-Simões; Paula Almeida Pamponet, Moura; Kelly, Colla; Anna Flávia Zonato, Tocchio; Camila Gomes de, Morais; Renata Augusta de, Miranda; Rogério Ribeiro, Robes; Sérgio Ossamu, Ioshii.

342

High-Strength Welds in Metallocene Polypropylene/Polyethylene Laminates  

Science.gov (United States)

Spectacular advances in organometallic chemistry over the past two decades have resulted in single-site catalysts that are revolutionizing production of polyethylene (PE) and isotactic polypropylene (iPP). This report describes an unanticipated benefit of metallocene-catalyzed semicrystalline polyolefins, namely welded joint strengths in PE/iPP laminates that can exceed the cohesive strength of the constituents. We propose that interfacial polymer entanglements, established in the molten state and subsequently anchored in chain-folded lamellae upon crystallization, are responsible for this intrinsic property. The poor adhesion exhibited by traditional Ziegler-Natta-catalyzed polyolefins is shown to derive from the accumulation of amorphous polymer, a by-product of the polymerization reactions, at the interface. These results should facilitate fabrication and improve the properties of composites based on materials that dominate the plastics industry.

Chaffin, Kimberly A.; Knutsen, Jeffrey S.; Brant, Patrick; Bates, Frank S.

2000-06-01

343

Use of Cellulose-Containing Fillers in Composites with Polypropylene  

Directory of Open Access Journals (Sweden)

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

Marina TAVROGINSKAYA

2011-07-01

344

Polypropylene grafted with glycidyl methacrylate using supercritical CO2 medium  

Directory of Open Access Journals (Sweden)

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.

M. H. Kunita

2006-06-01

345

Polypropylene grafted with glycidyl methacrylate using supercritical CO2 medium  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

M. H., Kunita; E. M., Girotto; E. C., Muniz; A. F., Rubira.

2006-06-01

346

Radiation resistance of polyolefins and their composites. Pt. 1. Polypropylene  

International Nuclear Information System (INIS)

The gel permeation chromatography, MFR, and ESR techniques were used to study the resistance to radiation, via molecular weight and viscosity determinations, in homopolymeric PP (Malten PJ 601 and PP 401), a propylene/ ethylene copolymer (Malten PJ 330) and PP modified with propylene/ethylene and ethylene/vinyl acetate copolymers (PP Mod MKE 93) each prepared at the INCT, Warsaw. The MKE 93 and Malten PJ 330 were found to be most resistant to fast electrons. Irradiation results in the degradation and simultaneous reduction of poly disparity in the PP examined MFR measurements and GPC gave consistent results. The higher the polypropylene molecular weight, the greater degree of degradation induced. The MKE 93, i.e., PP most resistant to radiation proved suitable for production of radiation-sterilized hypodermic syringes. (author). 15 refs, 6 tabs, 1 fig

347

Conifer fibers as reinforcing materials for polypropylene-based composites  

DEFF Research Database (Denmark)

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.

Plackett, David; Chengzhi, Chuai

2001-01-01

348

Effect of Natural Fiber Reinforced Polypropylene Composite Using Resin Impregnation  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, we deals with mechanical performance of resin impregnation with natural fiber and fiber reinforced composites. The effect of the addition of a rein impregnation process on static strength of the injection molded composites was investigated by carrying out tensile and banding tests, followed by Scanning electron microscopy (SEM observation of fiber surface and fracture surface of composites. The tensile strength of natural fiber and natural fiber reinforced composites with resin impregnation method increases with Polyvinyl alcohol (PVA impregnation. In addition, Phenol resin impregnation recovers fiber tensile strength after alkali treatment. Resin impregnation causes decrease in contact surface area; however, it does not cause decrease in mechanical properties. Our results suggest that the using rein impregnation method has better effect on the mechanical properties of natural fiber reinforced Polypropylene (PP composites.

Gibeop Nam

2014-11-01

349

Graft copolymerization of methacrylic acid monomers onto polypropylene fibers  

Directory of Open Access Journals (Sweden)

Full Text Available In recent years, graft copolymerization has been widely used to insert various functional groups onto polymers. In our study, methacrylic acid monomers are grafted to polypropylene (PP fibers to make them hydrophilic while maintaining their mechanical properties. Experiments are designed based on Taguchi’s method and influence of temperature, monomer concentration; cross-linker concentration and time of reaction are investigated. Grafting of methacrylic acid and divinyl benzene is investigated by FTIR spectra and confirmed by SEM micrographs. Tensile strength and toughness of specimens are measured and compared with raw fibers. Influence of grafting on the tensile strength and toughness of fibers are measured and critical grafting degree to maintain tensile strength and toughness of fibers is defined.

Mazhar Majid

2014-01-01

350

Packing parameters effect on injection molding of polypropylene nanostructured surfaces  

DEFF Research Database (Denmark)

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.

Calaon, Matteo; Tosello, Guido

2012-01-01

351

Polypropylene hollow fiber oxygenators: effect of the sorption of perfluoropolyethers.  

Science.gov (United States)

The introduction of microporous polypropylene hollow fibers in recent years has brought considerable advances to blood oxygenators. However, lifetime and assembly problems are still unresolved. In this work we tried to rate the oxygen permeation velocity by turning the fibers more hydrophobic through the sorption of a perfluorocarbon. Fomblin HC/25, a perfluoropolyether, is well known for its low surface tension and high affinity for oxygen. Celgard X10, X20, and X30 commercial hollow fibers were tested. The hollow fibers showed high affinity for the perfluoropolyether; swelling was clearly shown. A new system for the measurement of oxygen permeation velocity was developed. The oxygen transport velocity was not significantly changed after sorption. The Celgard microporous hollow fibers impregnated with perfluoropolyether showed no water permeation after 2 months of use, reducing one of the most serious problems in the lifetime of these types of fibers. PMID:10759633

Cassiola, F; Kiyohara, P K; Joekes, I

2000-03-01

352

Femtosecond laser ablation of polypropylene for breathable film  

International Nuclear Information System (INIS)

A polypropylene (PP) film was ablated using a femtosecond laser with a center wavelength of 785 nm, a pulse width of 184 fs and a repetition rate of 1 kHz. Increments of both the pulse energy and the shot number of pulses lead to co-occurrence of photochemical and thermal effect, demonstrated by the spatial expansion of rim on the surface of PP. The shapes of the laser-ablated PP films were imaged by a scanning electron microscope (SEM) and measured by a 3D optical measurement system (NanoFocus). And, the gas and water vapor transmission rate, mechanical properties of PP film micropatterned by fs laser pulses was characterized. Our results demonstrate that a femtosecond pulsed laser is an efficient tool for breathable packaging films in modifying the flow of air and gas, where the micropatterns are specifically tailored in size, location and number of which is easily controlled by laser processing conditions

353

Aqueous Processes for Dyeing Generic, Unmodified Polypropylene Fiber  

Directory of Open Access Journals (Sweden)

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.

Murari L. Gupta

2010-06-01

354

Grafting polymerization of acrylic acid onto preirradiated polypropylene fabric  

International Nuclear Information System (INIS)

Acrylic acid (AAc) was grafted onto polypropylene (PP) fabric by a preirradiation method using a Co-60 gamma ray. The effect of absorbed dose, AAc concentration, reaction temperature, reaction time, storage time, as well as the effect of ferrous ion and sulfuric acid on the degree of grafting were determined. It has been shown that the synergistic effect of sulfuric acid with the ferrous sulfate can not only increase the grafting yield, but also decrease the apparent activation energy for the grafting. It leads to the possibility of getting a particular grafting yield at a lower absorbed dose. In this experiment. It has also been shown that the grafting activity of pre-irradiated PP fabric in AAc aqueous solution could be well kept at room temperature for a long period

355

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

356

Cutaneous fistula from the gastric remnant resulting from a chronic suture-associated biofilm infection.  

Science.gov (United States)

A 53-year-old woman developed three chronic draining sinuses after Roux-en-Y gastric bypass; these persisted for almost 1 year despite antibiotics and local wound care. At approximately 1 year post-operatively, the drainage from the most superior sinus increased significantly and assumed a greenish hue, prompting concerns for gastrocutaneous fistula despite negative radiologic evaluation. At surgery, the patient was found to have a retained permanent multifilament suture at the base of each sinus, with associated inflammatory and fibrous tissue and a "slimy" matrix. Confocal laser scanning microscopy of both the explanted sutures and investing soft tissue revealed extensive bacterial biofilm formation. Also at surgery, a frank fistulous track was noted communicating the most superior suture/sinus to the gastric remnant, necessitating laparotomy and remnant gastrectomy in addition to removal of the foreign bodies (sutures) and concomitant panniculectomy. The patient has subsequently been free of complaint or finding for over 3 years. PMID:19672669

Kathju, Sandeep; Lasko, Leslie-Ann; Nistico, Laura; Colella, Joseph J; Stoodley, Paul

2010-02-01

357

Loss of rotator cuff tendon-to-bone interface pressure after reattachment using a suture anchor.  

Science.gov (United States)

The purpose of this study was to examine the tendon-to-bone interface pressure, contact area, and force after reattaching a tendon to bone by use of a suture and suture anchor. Repairs were made in 8 ovine shoulders in vitro, by use of 3 suture types in each: Ethibond, polydioxanone, or Orthocord. A Tekscan pressure sensor was placed between the tendon and bone and monitored for 1 hour after the repair. The principal finding was a significant loss of approximately 60% of the contact parameters immediately after the suture was tied, followed by further significant loss over the next hour to a mean of only 14% of the initial readings. We concluded that pressure measurement systems that only record the initial maximum pressure would yield overly optimistic results for the actual repair pressure after the repair is completed. The Tekscan system, however, allowed us to monitor pressure reductions that occurred both during and after the repair. PMID:18504147

Brassart, Nicolas; Sanghavi, Sanjay; Hansen, Ulrich N; Emery, Roger J; Amis, Andrew A

2008-01-01

358

Preliminary results with sutured colonic anastomoses reinforced with dye-enhanced fibrinogen and a diode laser  

Science.gov (United States)

A common cause of morbidity in patients recovering from bowel surgery is leakage from colonic anastomoses. A technique utilizing a laser activated protein solder to strengthen colonic anastomoses in a canine model was evaluated. Following creation of six single-layer interrupted suture anastomoses in four dogs, a protein solder consisting of indocyanine green dye and fibrinogen was topically appied to the serosal surface and exposed to 808 nm continuous wave diode laser energy. Immediately following anastomosis, the mean leakage pressure of sutures alone was 129 +/- 14 mm hg (n equals 6), while the mean leakage pressure of sutures reinforced with the laser welded solder was 312 +/- 32 mm hg (n equals 6) (p anastomosis demonstrated a layer of fibrinogen across the anastomotic gap without evidence of thermal injury. Laser activated protein solder significantly enhances the immediate strength of sutured colonic anastomoses without causing appreciable thermal injury to surrounding tissues.

Libutti, Steven K.; Williams, Matthew R.; Oz, Mehmet C.; Forde, Kenneth A.; Bass, Lawrence S.; Weinstein, Samuel; Auteri, Joseph S.; Treat, Michael R.; Nowygrod, Roman

1991-07-01

359

Tibial tubercle osteotomy for access during revision knee arthroplasty: Ethibond suture repair technique  

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Full Text Available Abstract Background Tibial Tubercle Osteotomy has shown much promise in revision total knee replacement. Methods of repair previously described include screw and wire fixation. Both methods have significant complications. Methods This article describes suture fixation of the osteotomy using Ethibond sutures placed medially with a lateral periosteal hinge. Results This method of fixation relies upon an adequate osteotomy segment including the entire insertion of the patella tendon. The lateral periosteal hinge is maintained and adds to the stability of the construct. A minimum of two number 5 Ethibond sutures are passed medially through drill holes to secure the osteotomy segment. No post-operative immobilisation is required. Conclusion Ethibond sutures provide adequate fixation of the tibial tubercle osteotomy segment in revision knee arthroplasty with reduced risk of complication as compared to conventional fixation methods.

Ghandour Adel

2008-06-01

360

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

Science.gov (United States)

...ethylene terephthalate) surgical suture. 878.5000 Section 878.5000 Food and Drugs FOOD AND DRUG ADMINISTRATION...PLASTIC SURGERY DEVICES Surgical Devices § 878.5000 Nonabsorbable poly(ethylene terephthalate)...

2010-04-01

 
 
 
 
361

Mechanical comparative analysis of three different types of sutures in different dimensions tendons: experimental study  

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Full Text Available The aim of this experimental investigation was study of mechanical profile of three kinds of suture, between tendons with different dimensions. Were utilized 21 mongrel dogs ( 11males, 10 females of wich were obtained the tendon comum flexor and tendon tibial cranial of both pelvic limbs. After the dissection of the tendons, suture was done, seven animal per group. The tendons utilized allways were from the right limb and from the left limb side utilized as control. After the suture, we performed axial traction tests, rate level of 30mm /min, using special jaws. After the test the machine's program informed the values of ultimate load, elongation and strain, and load elongation diagram. The results were submite to statistical study, that showed no difference between the technics utilized. The values of suture groups were smaller than the control, for ultimate load, and higher for elongation and strain.

Sardenberg Trajano

2002-01-01

362

Ameloblastin Inhibits Cranial Suture Closure by Modulating Msx2 Expression and Proliferation  

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Deformities of cranial sutures such as craniosynostosis and enlarged parietal foramina greatly impact human development and quality of life. Here we have examined the role of the extracellular matrix protein ameloblastin (Ambn), a recent addition to the family of non-collagenous extracellular bone matrix proteins, in craniofacial bone development and suture formation. Using RT-PCR, western blot and immunohistochemistry, Ambn was localized in mouse calvarial bone and adjacent condensed mesench...

Atsawasuwan, Phimon; Lu, Xuanyu; Ito, Yoshihiro; Zhang, Youbin; Evans, Carla A.; Luan, Xianghong

2013-01-01

363

Suture reaction following skin closure with subcuticular polydioxanone in total knee arthroplasty.  

Science.gov (United States)

A retrospective study revealed a 20% incidence of suture reaction following closure of wounds with subcuticular polydioxanone after total knee arthroplasty. In a control group whose wounds were closed with subcuticular polyglycolic acid (Dexon, Davis & Geck, Wayne, NJ), no suture reactions occurred (P = .0012, Fisher's exact test). It is concluded that subcuticular polydioxanone should not be used for skin closure after total knee arthroplasty. PMID:8934328

Casha, J N; Hadden, W A

1996-10-01

364

One stage vertical rectus muscle recession using adjustable sutures under local anaesthesia.  

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AIMS: To assess the results of visual axis alignment following one stage adjustable suture surgery to correct vertical diplopia. METHOD: Eight patients with a mean age of 44.9 years (range 16-80 years) complaining of vertical diplopia underwent rectus muscle recession under local anaesthesia with intraoperative adjustment of sutures. Diplopia was secondary to superior oblique paresis in four patients, dysthyroid eye disease in two patients, superior rectus paresis in one patient, and one deve...

Rauz, S.; Govan, J. A.

1996-01-01

365

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

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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...

Boileau, Pascal; Hardy, Marie-be?atrice; Mcclelland, Walter B.; The?lu, Charles-edouard; Schwartz, Daniel G.

2013-01-01

366

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

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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...

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

2014-01-01

367

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

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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.

Abhay Nilkanth Datarkar

2014-09-01

368

The use of releasable sutures in Molteno glaucoma implant procedures to reduce postoperative hypotony.  

Science.gov (United States)

We used releasable sutures to minimize immediate postoperative hypotony and flat anterior chamber in 19 cases of refractory glaucoma requiring insertion of a single-plate Molteno implant in a one-stage procedure. A slip knot using 7-0 nylon suture was fashioned around the Molteno tube under a lamellar scleral flap. In 18 of the 19 eyes, anterior chamber depth was normal immediately after surgery. PMID:2038480

el-Sayyad, F; el-Maghraby, A; Helal, M; Amayem, A

1991-02-01

369

Subcutaneous vicryl suture covering efficacy on wound complications after cesarean section  

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Background: Increasing abdominal subcutaneous tissue thickness is a risk factor for postoperative complications in obese women who underwent cesarean section (C/S). Different strategies have used to decrease the wound complications. Using antibacterial vicryl suture to decrease infectious complications has been studied for several years. Present study assesses the effect of subcutaneous closure with antibacterial vicryl suture on decreasing wound complications in obese women with C/S. Methods...

Negin Rezavand; Shohre Malekkhosravi; Firoozeh Veisi; Mariam Zangeneh; Kamelia Hemiari; Mansour Rezaei

2011-01-01

370

Clinical observation on ciliary groove suture fixation of posterior chamber intraocular lens  

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AIM: To investigate the operation skills of keeping the intraocular lens centering and stabilizing and decreasing the complications in ciliary groove suture of posterior chamber intraocular lens. METHODS: Totally 31 cases(31 eyes)undergone ciliary groove suture fixation with posterior chamber type of soft intraocular lens, fixing the position of the lens' optical surface stably in the middle by horizontal marking before or during the operations, locating and burning the puncture point, fix...

Shi-Hua Zhang; Na Li; Shu-Hong Cai

2013-01-01

371

Risk/benefit evaluation of the use of triclosan in surgical suturing materials  

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Based on the current literature, a risk/benefit analysis of the antimicrobial impregnation of surgical sutures with triclosan is performed, focussing on efficacy and indication, risk of resistance development, toxicological characteristics, and environmental tolerance. From a toxicological point of view, there are no restrictions for triclosan-impregnated suturing materials. Environmental tolerance is also acceptable for this application area, because the amounts of triclosan involved pose no...

Lippert, Hans; Ju?nger, Michael; Heidecke, Claus-dieter; Guggenbichler, Josef Peter; Assadian, Ojan; Kramer, Axel; Schauer, Frieder

2006-01-01

372

Arthroscopic suture anchor repair of posterior root attachment injury in medial meniscus: technical note.  

Science.gov (United States)

A root attachment injury (root tear) of the meniscus can abolish the ability of the meniscus to bear hoop stress and predispose to increase articular contact stress which contribute to femorotibial degenerative changes. A pull out suture technique to repair the root tear has been described, but the procedure making the tibial tunnel may be difficult and troublesome. This article describes a repair technique using a suture anchor and posterior trans-septal portal. PMID:19142649

Kim, Jae-Hwa; Shin, Dong-Eun; Dan, Jin-Myong; Nam, Ki-Shik; Ahn, Tae-Keun; Lee, Dong-Hoon

2009-08-01

373

Preliminary observation of extraocular muscles adjustable suture for partial accommodative esotropia surgery in children  

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AIM:To investigate the efficacy of adjustable suture on partial accommodative esotropia surgery in children. METHODS: Thirty children with partial accommodative esotropia were treated by the recession of binocular medial rectus combined adjustable suture. The inclusion criteria were medium hypermetropia, and having wear sufficient degree mirror no less than six months, residual nonaccommodative esotropia deviation of +20? ? +35?. 3mm to 5mm recession of binocula...

Xiao-Lei Tang; Xiao-Li Wang; Xiao-Hu Chen; Ran Zhang; Xiao-Hong Zeng

2014-01-01

374

Novel Suture-Less Vascular Anastomotic Device (BYFix) in Femoro-Popliteal Surgery, Early Clinical Experience  

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Objectives: To evaluate the early experience of using the BYFix-innovative anastomotic device for creating suture-less vascular anastomosis in major and peripheral arteries surgery. Design: Uncontrolled prospective study. Materials: The BYFix anastomotic device for suture-less vascular anastomosis with surgical tools and standard vascular grafts. Methods: 7 patients, age 63.6 ± 9.2 years, with peripheral vascular occlusion above the knee scheduled for surgical repair were operared. They unde...

Schneider, M.; Shapira, V.; Chernyavskiy, V.; Yoffe, B.

2011-01-01

375

Patterns and implications of extensive heterochrony in carnivoran cranial suture closure  

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Heterochronic changes in the rate or timing of development underpin many evolutionary transformations. In particular, the onset and rate of bone development have been the focus of many studies across large clades. In contrast, the termination of bone growth, as estimated by suture closure, has been studied far less frequently, although a few recent studies have shown this to represent a variable, although poorly understood, aspect of developmental evolution. Here, we examine suture closure pa...

Goswami, A.; Foley, L.; Weisbecker, V.

2013-01-01

376

Delayed primary suture of flexor tendons cut in the digital theca.  

Science.gov (United States)

The results of delayed primary suture of flexor tendons cut in the digital theca in twenty five patients, thirty three affected fingers, are given. The patients had their skin closed at another hospital immediately after the injury. One to six days later the skin stitches were removed and tendon suture was performed. Excellent and very good results are obtained in 79.7% of all thirty three fingers operated upon. PMID:6997144

Matev, I; Karagancheva, S; Trichkova, P; Tsekov, P

1980-06-01

377

Differential growth on sutures of tendon cells derived from torn human rotator cuff.  

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Rotator cuff tendon pathology is proposed to account for 30-70% of all shoulder pain and surgical repair with a nonabsorbable suture is the common option for painful rotator cuff tears that have failed conservative treatment. A number of studies have suggested the beneficial effect of augmenting the repair with implants constructed from polymers used for sutures. Thus, it was of interest to investigate the affinity of tendon-derived fibroblasts, often thought to be the repairing agents of tor...

Hakimi, O.; Chaudhury, S.; Murphy, R.; Carr, A.

2012-01-01

378

Mechanical behavior and morphology of compatible polypropylene and polyamide 6 blends  

International Nuclear Information System (INIS)

In this work, the effect of different reactive compatibilizers on the mechanical properties and morphology of Polypropylene and Polyamide 6 blends was investigated. The blends were prepared in a counter-rotating twin screw extruder and samples for the tests were injection molded. The blends were characterized by X-Ray diffraction, mechanical properties and Scanning Electron Microscopy. X-Ray Diffraction results showed that the Polypropylene beta phase (hexagonal) was formed due to the presence of Polyamide 6. The compatibilizers considerably improved the mechanical properties of Polypropylene and Polyamide 6 blend. The addition of the compatibilizers reduced the Polyamide 6 particles average size and improved the adhesion between the Polypropylene and Polyamide 6 phases. (author)

379

Application of FTIR microspectroscopy to characterize the diffusion of Cyasorb UV531 in polypropylene  

Science.gov (United States)

An IR microprobe application was developed to characterize the diffusion profiles of additives in polymers. The diffusion of Cyasorb UV531 in polypropylene was studied and concentration profiles, diffusion coefficients were obtained.

Lin-Vien, Daimay; Hsu, Shin-Chu; French, R. N.

1992-03-01

380

Crystallization of polypropylene: application of differential scanning calorimetry. Part 2. Crystal forms and nucleation  

International Nuclear Information System (INIS)

The influence of homogeneous and heterogeneous nucleation on crystallization processes of isotactic polypropylene (ipp) and its kinetic and thermodynamic parameters is summarized and discussed, as evaluated by DSC measurements.

 
 
 
 
381

Effect of processing conditions on the mechanical and thermal properties of high-impact polypropylene nanocomposites  

Energy Technology Data Exchange (ETDEWEB)

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.

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

382

Improvement of radiation resistance of polypropylene by blending with polyethylene and polystyrene  

International Nuclear Information System (INIS)

The use of polypropylene in production of medical component and packaging materials makes it an interesting material for applied research. Since the use of ethylene oxide for sterilization of medical components will be forbidden in the next future because of its carcinogens effect. Therefore, another alternative sterilization methods are required. The use of Gamma radiation is already established for sterilization of some medical components, this technique causes change in the physical mechanical properties of polypropylene, which makes the addition of stabilizers necessary. In this work, blends of domestically used polymers, polypropylene, linear low-density polyethylene, and polystyrene/butadiene were prepared in order to improve the radiation resistance of polypropylene; naphthalene was also used as an additive

383

Analysis of Flexural Strength for Steel, Glass and Polypropylene Fiber Reinforced Concrete  

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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...

Venkata Ramana, Chapala Venkata X.; Ch, Naga Sindhura

2012-01-01

384

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)

385

Plate fixation of premaxillomaxillary suture and compensatory midfacial growth changes in the rabbit.  

Science.gov (United States)

It has been suggested that rigid fixation of the developing craniofacial skeleton may lead to altered craniofacial growth. However, recent experimental studies have shown that microplate fixation of slow-growing calvarial sutures resulted in regional growth disturbances but had little effect on overall craniofacial growth. The present study was designed to assess the effects of microplate fixation of the more rapidly growing facial sutures on compensatory midfacial growth in the rabbit. Twenty-two 1.5-week-old rabbits were randomly divided into 2 groups: sham controls (n = 11) and animals with bilateral premaxillomaxillary suture fixation (n = 11). Fixation was accomplished using an intraoral approach, a 6-mm straight Luhr microplate, and two 2-mm long self-tapping screws across each suture. Serial lateral head radiographs were collected at 1.5, 3.5, 6, 12, and 18 weeks of age. Results revealed that by 3.5 weeks, animals with rigid fixation showed significantly shortened premaxillary lengths (p fixation compared with shams. Gross examination of the cleaned and dried skulls revealed bony bridging across the premaxillomaxillary suture and osseous fracture lines extending superiorly from the site of screw fixation. Results demonstrated that rigid fixation of a rapidly growing facial suture did not impair long-term midfacial growth in the rabbit model and suggest that compensatory changes may have occurred at fracture lines from the self-tapping screws in these animals. PMID:1298421

Mooney, M P; Losken, H W; Siegel, M I; Tsachakaloff, A; Losken, A; Janosky, J

1992-12-01

386

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

Directory of Open Access Journals (Sweden)

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.

Sood Archana

2003-01-01

387

Diathermy-induced inflammation does not affect suture holding capacity of intestinal anastomoses.  

Science.gov (United States)

We compared the suture holding capacity of rat intestinal anastomoses after division of the bowel with scissors or diathermy. Two sets of experiments differing in suture technique were done. In one set the amount and solubility of anastomotic collagen were measured, and neutrophil accumulation quantified with a myeloperoxidase (MPO) assay. MPO activity 24 h after surgery was 60% higher (p less than 0.05) after division with diathermy than after division with scissors. Suture holding capacity (breaking strength) decreased by approximately 70% (p less than 0.001) in both groups when sutures were inserted near the bowel edges, while no decrease was noted when sutures were inserted at a farther distance, regardless of the mode of bowel division. After 7 days MPO levels approached baseline values in both groups and the bowel always ruptured outside the anastomosis. Collagen content was not adversely affected by diathermy. Although the reduction in early anastomotic strength may be mediated by local neutrophil activity, suture holding capacity was not influenced by the increased neutrophil accumulation elicited by diathermy. PMID:1782969

Jonsson, T; Högström, H

1991-01-01

388

Effect of Polypropylene Fiber on Shrinkage Properties of Cement-stabilized Macadam  

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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...

Zhifeng Chen

2009-01-01

389

Evaluation of the Shear Strength Behaviour of Polypropylene and Carbon Fibre Reinforced Cohesive Soils  

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The purpose of this study is to investigate the influence of various parameters involved, such as the strength properties of fibres, the relative size of fibres and grains and the rate of shear on the shear strength of polypropylene or carbon fibre reinforced cohesive soils with different percentage loading of fibres. The experimental results reveal that the inclusion of polypropylene fibres in soil increases considerably the shear strength. Contrarily, the inclusion of the carbon fibres did ...

Anagnostopoulos, Costas A.; Dimitrios Tzetzis; Kyriakos Berketis

2014-01-01

390

LIGNIN-STIMULATED PROTECTION OF POLYPROPYLENE FILMS AND DNA IN CELLS OF MICE AGAINST OXIDATION DAMAGE  

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The blending of polypropylene with lignin derived from chemical wood pulp manufacture makes it possible to prepare optically transparent films (thickness 50-60?m) with acceptable mechanical properties in the absence of a commercial stabilizer. The lignin preparation in the concentration 1-2 wt% possessed the ability to act as a processing stabilizer and as an antioxidant during thermal aging of polypropylene films. A DNA-protective effect of lignin in mice testicular cells and mice periphera...

Božena Košíková; Juraj Lábaj

2009-01-01

391

Mechanical Properties and Energy-saving Effect of Polypropylene Fiber Foam Concrete  

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Compared with ordinary concrete, foam concrete possesses advantages such as lightweight, heat insulation, etc., but the internal bubbles have of great influence on its strength. This study examined the impact of polypropylene fibers on mechanical properties of foam concrete using flexural deformation control method and obtained complete load-deformation curve. The results show that, polypropylene fibers significantly affect the compressive property of the foam concrete and improve the carryin...

Deng Fukang

2013-01-01

392

Electrochemical Impedance Study of Zinc Yellow Polypropylene-Coated Aluminum Alloy  

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Performance of zinc yellow polypropylene-coated aluminum alloy 7B04 during accelerated degradation test is studied using electrochemical impedance spectroscopy (EIS). It has been found that the zinc yellow polypropylene paint has few flaw and acts as a pure capacitance before accelerated test. After 336-hour exposure to the test, the impedance spectroscopy shows two time constants, and water has reached to the aluminum alloy/paint interface and forms corrosive microcell. For the scratched sam...

Feng Lu; Ming Liu; Jian-ping Cai; Zhi-hua Sun; Ni Zhang

2010-01-01

393

Enhancing the Dyeability of Polypropylene Fibers by Melt Blending with Polyethylene Terephthalate  

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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 correspondi...

Fereshteh Mirjalili; Siamak Moradian; Farhad Ameri

2013-01-01

394

Fibrous ionites on the base of radiation-grafted polypropylene fibers  

International Nuclear Information System (INIS)

The methods of radiation grafting of acrylic acid and polypropylene-divinylbenzene copolymer on polypropylene fibers using the research installation RKhM-?-20 are considered. The pilot production of grafted fibers on the installation UGU-420 and fibrous ionites on their base FIBAN K-1, FIBAN K-4 and FIBAN A-1 are described. The mechanical and sorptive properties of the ionites as well as the areas of their application are under consideration

395

Tensile strength characteristics of polypropylene composites reinforced with stone groundwood fibers from softwood  

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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 compos...

Joan P. López,; José A. Méndez,; Francesc X. Espinach,; Fernando Julián,; Pere Mutjé; Fabiola Vilaseca

2012-01-01

396

Does the type of suturing technique used affect astigmatism after deep anterior lamellar keratoplasty in keratoconus patients?  

Directory of Open Access Journals (Sweden)

Full Text Available Banu Torun Acar, Ece Turan Vural, Suphi AcarHaydarpasa Numune Education and Research Hospital, Ophthalmology Clinic, Istanbul, TurkeyPurpose: To compare the effect of three different suturing techniques on astigmatism after deep anterior lamellar keratoplasty (DALK in patients with keratoconus.Methods: In this retrospective study, 54 eyes of 54 patients with advanced keratoconus underwent DALK with three suturing techniques: single running, interrupted running, and combined interrupted and running. Postkeratoplasty astigmatism was evaluated during examinations 1, 3, and 6 months postoperatively and 2 months after completing suture removal.Results: Twenty-four eyes had single running sutures, 16 eyes had interrupted sutures, and in 14 eyes the suturing technique used was combined interrupted and running sutures. Mean age was 25.6 ± 5.9 years, 27.3 ± 6.8 years, and 26.5 ± 5.7 years (P = 0.422, and postoperative astigmatism 1 month after surgery was 3.79 ± 1.19 D, 5.56 ± 1.78 D, and 4.21 ± 1.55 D in the three groups, respectively (P = 0.012. However, 2 months after completing the suture removal, final postoperative astigmatism was 3.43 ± 1.44 D, 3.87 ± 1.38 D, and 3.71 ± 1.46 D (P = 0.846. Final astigmatism less than 4 D was seen in 18 cases (75% in the single running group, nine cases (56.2% in the interrupted running group, and nine cases (64.2% in the combined interrupted and running group (P = 0.08.Conclusion: Postkeratoplasty astigmatism is comparable with three different suturing techniques used in patients with keratoconus after completing suture removal in DALK. Due to earlier suture removal in DALK, the type of suturing technique used is not considerably important.Keywords: astigmatism, deep anterior lamellar keratoplasty, suturing technique

Acar BT

2011-04-01

397

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

398

Thermal and mechanical properties of polypropylene/titanium dioxide nanocomposite fibers  

International Nuclear Information System (INIS)

Highlights: ? Wet synthesis method was used for the synthesis of TiO2 nano particles. ? Mechanical properties of polypropylene fibers were increased by the addition of TiO2 nanoparticles. ? Thermal stability of polypropylene fiber was improved significantly by the addition of TiO2 nano particles. ? 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.

399

Effect of compatibilization and reprocessing on the isothermal crystallization kinetics of polypropylene/wood flour composites  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

Arieny, Rodrigues; Benjamim de M., Carvalho; Luís A., Pinheiro; Rosário E. S., Bretãs; Sebastião V., Canevarolo; Juliano, Marini.

400

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.

 
 
 
 
401

Surface modification of polypropylene and compatibilization of interfaces in incompatible blends of polypropylene with polystyrene by plasma of CO{sub 2}  

Energy Technology Data Exchange (ETDEWEB)

The effect of surface modification of polypropylene (PP) film is induced by CO{sub 2} 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 CO{sub 2}. Transition layer thickness is measured by small angle light scattering (SALS).

Ma Guiqiu; Liu Xiangning; Huang Dinghai; Yuan Xubo [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Nankai District Weijin Road No. 92, Tianjin 300072 (China); Sheng Jing, E-mail: shengjing@tju.edu.cn [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Nankai District Weijin Road No. 92, Tianjin 300072 (China)

2009-06-15

402

ESEM study of oil wetting behaviour of polypropylene fibres; Etude ESEM de la mouillabilite des fibres de polypropylene par l'huile  

Energy Technology Data Exchange (ETDEWEB)

Polypropylene (PP) fibres have been increasingly used in oil related areas, such as oil sorbents, oil coalescers, oil filters and oil separators. The wetting behaviour of the fibres by oil is of particular importance in these applications. The environmental scanning electron microscope (ESEM) technique was used ire this study to investigate the oil wetting of polypropylene fibres. The wettability was investigated by contact angle measurements with oil. Oil drops were added onto fibres using a micro-injector. The contact angles were measured from ESEM micrographs using image analysis and theoretical approach. ESEM observation reveals the wetting of single fibres on a microscopic level. (authors)

Wei, Q.F.; Mather, R.R.; Fotheringham, A.F.; Yang, R. [Heriot-Watt Univ. Scottish, Galashiels TD (United Kingdom); Buckman, J. [Heriot-Watt Univ., Institute of Petroleum Engineering, Edinburgh (United Kingdom)

2003-07-01

403

Comparison of CO2 laser welding with suture technique for repair of tendons  

Science.gov (United States)

The purpose of this study was to evaluate the efficacy, histology, and strength of laser welding in repair of sharply transected rat Achilles tendons. In 26 adult, male Sprague-Dawley rats, the severed tendons were repaired with a 7-0 nylon, modified Kessler core suture followed by either a running 9-0 nylon epitendinous suture or a circumferential CO2 laser epidendinous weld using 25% human albumin as a solder. All repairs were timed and post- operative tensile strength was analyzed with material testing equipment. In addition, histologic testing was performed on both types of repairs. The mean time to complete the epitendinous repair in the laser group was 3.5 minutes and in the suture group, 8 minutes. The mean ultimate tensile strength in 6 normal tendons was 40.9 Newtons (N) with group standard deviation of 5.2 N. When compared with normal controls, post-operatively both types of tendon repairs resulted in tensile failure at lower forces. The ultimate tensile strength for the epitendinous suture repair and the laser welds were 13% and 6% of normal controls, respectively. Twenty tendons with epidendinous suture repair had mean ultimate tensile strength of 5.4 (+/- 1.2) N, while the 17 tendons with laser wends failed at 2.6 (+/- 0.9) N. Histologic evaluation of tendons repaired with CO2 laser revealed areas of coagulation and edema on the surface of tendon edges. Post-operatively, greater tissue changes were noted in laser treated tendons than those repaired with sutures. Laser welding of epitenon is possible and can be completed faster than the suture repair. The repaired tendon surface appears smoother and less bulky after laser treatment. However, significantly decreased immediate post-operative strength was demonstrated by the use of Kruskal-Wallis one way analysis of variance and Turkey's pairwise comparison.

Popovic, Neven A.; Johnstone, Frederic L.; Kilkelly, Francis X.; McKinney, LuAnn; Van De Merwe, Willem P.; Smith, Allan C.

1995-05-01

404

Does the type of suturing technique used affect astigmatism after deep anterior lamellar keratoplasty in keratoconus patients?  

Science.gov (United States)

Purpose: To compare the effect of three different suturing techniques on astigmatism after deep anterior lamellar keratoplasty (DALK) in patients with keratoconus. Methods: In this retrospective study, 54 eyes of 54 patients with advanced keratoconus underwent DALK with three suturing techniques: single running, interrupted running, and combined interrupted and running. Postkeratoplasty astigmatism was evaluated during examinations 1, 3, and 6 months postoperatively and 2 months after completing suture removal. Results: Twenty-four eyes had single running sutures, 16 eyes had interrupted sutures, and in 14 eyes the suturing technique used was combined interrupted and running sutures. Mean age was 25.6 ± 5.9 years, 27.3 ± 6.8 years, and 26.5 ± 5.7 years (P = 0.422), and postoperative astigmatism 1 month after surgery was 3.79 ± 1.19 D, 5.56 ± 1.78 D, and 4.21 ± 1.55 D in the three groups, respectively (P = 0.012). However, 2 months after completing the suture removal, final postoperative astigmatism was 3.43 ± 1.44 D, 3.87 ± 1.38 D, and 3.71 ± 1.46 D (P = 0.846). Final astigmatism less than 4 D was seen in 18 cases (75%) in the single running group, nine cases (56.2%) in the interrupted running group, and nine cases (64.2%) in the combined interrupted and running group (P = 0.08). Conclusion: Postkeratoplasty astigmatism is comparable with three different suturing techniques used in patients with keratoconus after completing suture removal in DALK. Due to earlier suture removal in DALK, the type of suturing technique used is not considerably important. PMID:21499568

Acar, Banu Torun; Vural, Ece Turan; Acar, Suphi

2011-01-01

405

The use of synthetic absorbable suture materials (polyglycolic acid and polydioxanone) in the low pressure circulatory system of growing organisms.  

Science.gov (United States)

Synthetic absorbable sutures were used for surgery in the cardiovascular low pressure system of growing beagle dogs. Right atrial incisions were closed with this material in 20 dogs. In another 20 dogs caval anastomoses were performed in continuous suture technique. Repeated angiographies and histological examination were performed after observation periods between 5 and 180 days. No clinical complications occurred. Postoperatively patent anastomoses grew with the surrounding tissue, while stenotic anastomoses attained normal luminal diameter after suture absorption. Synthetic absorbable suture materials are recommended for use in the cardiovascular low pressure system, especially in the correction of congenital anomalies. PMID:2424128

Töns, C; Armbrecht, J; Bircks, W

1986-04-01

406

Rapidly resorbable vs. non-resorbable suture for experimental colonic anastomoses in rats--a randomized experimental study  

DEFF Research Database (Denmark)

Anastomotic dehiscence remains an important challenge for colorectal surgeons worldwide. Extensive research focused on performing a safe anastomosis is conducted with rats being the most used model when examining colorectal anastomoses. In daily clinical practice resorbable sutures are used when hand-sewn anastomoses are performed. However, in the experimental studies examining colorectal anastomoses, non-resorbable sutures have predominantly been used. The aim of this study was to compare a rapidly resorbable suture with a non-resorbable suture in experimental colorectal anastomoses.

Klein, Mads; Pommergaard, Hans-Christian

2011-01-01

407

Pulsed and CW NMR study of drawn polypropylene fibres  

International Nuclear Information System (INIS)

Pulsed and broad-line proton NMR was used in investigation of both the molecular motions and the relaxations in oriented partially crystalline polypropylene (PP) fibres. Proton NMR measurements were made of the spin-lattice and rotating-frame relaxation times (T1, T1r resp.), spectra unfolding into elementary components and the second moment of the spectra in the temperature range of 250-400 K for three kinds of drawn PP fibres. The fibres were made from isotactic PP marked as Tatren 430 produced by Slovnaft Bratislava. Relaxation time T1 was measured by a multiple-pulse saturation recovery method. Rotating-frame data T1r were obtained with radiofrequency field B1=1.7 mT using the spin-locking method. The results of the experiments show that the differences in nuclear relaxation behavior are closely related to the structural changes (crystallinity and orientation) caused by the drawing process at different temperatures. (Z.S.) 4 figs., 10 refs

408

Morphological, rheological and mechanical characterization of polypropylene nanocomposite blends.  

Science.gov (United States)

In the present work, the effectiveness of styrene/ethylene-butylene/styrene rubbers grafted with maleic anhydride (MA) and a metallocene polyethylene (mPE) as toughening materials in binary and ternary blends with polypropylene and its nanocomposite as continuous phases was evaluated in terms of transmission electron microscopy (TEM), scanning electron microscopy (SEM), oscillatory shear flow and dynamic mechanical thermal analysis (DMA). The flexural modulus and heat distortion temperature values were determined as well. A metallocene polyethylene and a polyamide-6 were used as dispersed phases in these binary and ternary blends produced via melt blending in a corotating twin-screw extruder. Results showed that the compatibilized blends prepared without clay are tougher than those prepared with the nanocomposite of PP as the matrix phase and no significant changes in shear viscosity, melt elasticity, flexural or storage moduli and heat distortion temperature values were observed between them. However, the binary blend with a nanocomposite of PP as matrix and metallocene polyethylene phase exhibited better toughness, lower shear viscosity, flexural modulus, and heat distortion temperature values than that prepared with polyamide-6 as dispersed phase. These results are related to the degree of clay dispersion in the PP and to the type of morphology developed in the different blends. PMID:18572576

Rosales, C; Contreras, V; Matos, M; Perera, R; Villarreal, N; García-López, D; Pastor, J M

2008-04-01

409

Anticoagulant and antimicrobial finishing of non-woven polypropylene textiles  

International Nuclear Information System (INIS)

The aim of this work is to prepare non-woven polypropylene (PP) textile functionalized with bioactive molecules in order to improve its anticoagulation and antibacterial properties. This paper describes the optimization of the grafting process of acrylic acid (AA) on low-pressure cold-plasma pre-activated PP, the characterization of the modified substrates and the effect of these modifications on the in vitro biological response towards cells. Then, the immobilization of gentamicin (aminoglycoside antibiotic) and heparin (anticoagulation agent) has been carried out on the grafted samples by either ionic interactions or covalent linkages. Their bioactivity has been investigated and related to the nature of their interactions with the substrate. For gentamicin-immobilized AA-grafted samples, an inhibition radius and a reduction of 99% of the adhesion of Escherichia coli have been observed when gentamicin was linked by ionic interactions, allowing the release of the antibiotic. By contrast, for heparin-immobilized AA-grafted PP samples, a strong increase of the anticoagulant effect up to 35 min has been highlighted when heparin was covalently bonded on the substrate, by contact with the blood drop. (paper)