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Sample records for 10-0 polypropylene suture

  1. 21 CFR 878.5010 - Nonabsorbable polypropylene surgical suture.

    Science.gov (United States)

    2010-04-01

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

  2. Comparison of 10-0 nylon suture with 8-0 absorbable suture in strabismus surgery

    Directory of Open Access Journals (Sweden)

    Yang-Li Huang

    2015-08-01

    Full Text Available AIM:To compare 10-0 nylon suture with 8-0 absorbable suture on conjunctival incision in microscopy strabismus surgery. METHODS:The patients undergone esotropia or exotropia surgery in our hospital were selected and randomly divided into two groups: conjunctival incision of 32 patients(41 eyeswas sutured using 10-0 nylon in control group and that of 30 patients(38 eyesused 8-0 absorbable suture in observation group. All patients of two group were sutured using intermittently, knot buried method. Wound healing, patients perceived irritation were observed and compared at postoperative 1, 2wk and 1mo.RESULTS: Postoperative 1 and 2wk, the number of suture absorption and incision gaping were 7 and 15 eyes in observation group, with total incidence rate of 39%, while there was no suture absorption and incision gaping occurred in control group, the incidence was 0, the difference was statistically significant between the two groups(PP>0.05. Comparing the mean postoperative wound healing time, it was 22.30±5.45d in observation group and 15.50±1.76d in control group, the difference was statistically significant(PP>0.05. Postoperative 1mo, ocular comfort scores in control group(2.57±0.50was higher than that in observation group(1.813±0.64, the difference was statistically significant(PCONCLUSION: There was no difference using 10-0 nylon suture or 8-0 absorbable suture to suture conjunctival incision in microscopy strabismus surgery. Due to premature absorption of sutures, the incision healed delayed. 10-0 suture is recommend to suture bulbar conjunctiva in microscopy strabismus surgery.

  3. Selective laser vaporization of polypropylene sutures and mesh

    Science.gov (United States)

    Burks, David; Rosenbury, Sarah B.; Kennelly, Michael J.; Fried, Nathaniel M.

    2012-02-01

    Complications from polypropylene mesh after surgery for female stress urinary incontinence (SUI) may require tedious surgical revision and removal of mesh materials with risk of damage to healthy adjacent tissue. This study explores selective laser vaporization of polypropylene suture/mesh materials commonly used in SUI. A compact, 7 Watt, 647-nm, red diode laser was operated with a radiant exposure of 81 J/cm2, pulse duration of 100 ms, and 1.0-mm-diameter laser spot. The 647-nm wavelength was selected because its absorption by water, hemoglobin, and other major tissue chromophores is low, while polypropylene absorption is high. Laser vaporization of ~200-μm-diameter polypropylene suture/mesh strands, in contact with fresh urinary tissue samples, ex vivo, was performed. Non-contact temperature mapping of the suture/mesh samples with a thermal camera was also conducted. Photoselective vaporization of polypropylene suture and mesh using a single laser pulse was achieved with peak temperatures of 180 and 232 °C, respectively. In control (safety) studies, direct laser irradiation of tissue alone resulted in only a 1 °C temperature increase. Selective laser vaporization of polypropylene suture/mesh materials is feasible without significant thermal damage to tissue. This technique may be useful for SUI procedures requiring surgical revision.

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

    Directory of Open Access Journals (Sweden)

    Mallikarjun

    2015-07-01

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

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

    LENUS (Irish Health Repository)

    Davis, N F

    2012-11-01

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

  6. 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)

  7. Endoscopic removal of intravesical polypropylene suture with plasmakinetic resection after abdominal hysterectomy

    Science.gov (United States)

    Küçükdurmaz, Faruk; Can, Selman; Barut, Osman

    2014-01-01

    INTRODUCTION Intravesical foreign substances such as mesh or suture are among the rare reasons of recurrent urinary tract infections. Anti-incontinence and prolapsus procedures are associated with mesh/suture extrusion into the bladder, however, this complication is uncommon with abdominal hysterectomy. PRESENTATION OF CASE A 61-year-old female, obese patient admitted to our clinic with recurrent urinary tract infections and voiding symptoms which were worsened after abdominal hysterectomy. Radiological evaluation revealed an intravesical foreign material within the bladder. The cytoscopy was performed and a polypropylene suture which was inserted from dome, passed through the base and exited from the dome of bladder during abdominal hysterectomy. Transurethral plasmakinetic resection of superficial layer of urothelium between suture entrance and exit sites was performed and suture was removed from the bladder. DISCUSSION Urogynecological procedures are associated with the increased risk of urethral or ureteral injury, intravesical mesh or suture erosion and fistulae formation. Many different techniques including open, laparoscopic and transvaginal approaches were described for the removal of intravesical mesh/suture extrusion in the literature. Transurethral approach with its minimally invasive and safe nature was used to remove suture in this patient. This technique with the use of plasmakinetic energy has the advantage of decreased risk of bleeding and urothelial injury when compared to monopolar cautery. It also avoids the need for open or extensive surgery which may have a high rate of complications. CONCLUSION Transurethral resection is the treatment of choice for the removal of intravesical foreign substances. Use of plasmakinetic energy will decrease the risk of complications and avoid the need for open interventions. PMID:25437667

  8. Creep rupture behavior of polypropylene suture material and its applications as a time-release mechanism

    International Nuclear Information System (INIS)

    The controlled failure of polypropylene (PP) sutures is studied via creep rupture tests. From plots of log time (tB) vs. stress (sigma), linear relationships are generated over the failure times of 1-1000 h. Results show that as a function of stress, the time dependence varies with irradiation dose (15, 20, 25, and 50 Mrad), irradiation atmosphere (air and vacuum), suture diameter (7-0, 6-0, 5-0, and 4-0), and test temperature (26 and 37 degrees C). For a given stress, the time to failure is least for the greatest dose in the presence of air and at the highest temperature. When suture loops are wrapped around a small wire sheave, however, failure occurs in the largest suture as much as two decades sooner than the smallest suture studied. Within the limitations stated herein, they are independent of test method, loop diameter, aging, and humidity. Consequently, after irradiation in vacuum and postirradiation heat treatment, the processed material may be stored at room temperature for at least 1 month. Such materials are advocated when the time release of a dental or medical device is required, for example, in the self-activating cleft palate appliance

  9. 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.

  10. Endoscopic removal of intravesical polypropylene suture with plasmakinetic resection after abdominal hysterectomy

    OpenAIRE

    Faruk Küçükdurmaz; Selman Can; Osman Barut

    2014-01-01

    INTRODUCTION: Intravesical foreign substances such as mesh or suture are among the rare reasons of recurrent urinary tract infections. Anti-incontinence and prolapsus procedures are associated with mesh/suture extrusion into the bladder, however, this complication is uncommon with abdominal hysterectomy. PRESENTATION OF CASE: A 61-year-old female, obese patient admitted to our clinic with recurrent urinary tract infections and voiding symptoms which were worsened after abdominal hysterecto...

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

    OpenAIRE

    J. F Akinrinmade; Lawal, A. O.

    2010-01-01

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

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

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    Pankaj Shivhare

    2014-06-01

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

  13. Surgical treatment of traumatic eventration with polyester button and polypropylene mesh to strengthen the suture technique in equine

    OpenAIRE

    Orlandini, Carla Faria; Steiner, Denis; Boscarato, André Giarola; Gimenes, Gabriel Coelho; Alberton, Luiz Romulo

    2016-01-01

    Background Defects in the abdominal wall of horses have high relapse rate. This is mainly in lateral eventrations and hernias caused by trauma from kicks of other horses or installation structures. The eventration region normally becomes swollen and there may be complications due to intestinal loop incarceration. The surgical treatment, consisting of reconstruction of the abdominal wall, frequently require biological or synthetic materials for the reinforcement of the suture line and tension ...

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Nelson Leonardo Kerdahi Leite de Campos

    2003-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Álvaro Gianlupi

    2004-04-01

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

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

    International Nuclear Information System (INIS)

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

  18. A comparison of 2 different suture patterns for skin closure of canine ovariohysterectomy

    OpenAIRE

    Sylvestre, Anne; Wilson, Jeff; Hare, Jonathan

    2002-01-01

    The purpose of this study was to compare postoperative wound healing in canine ovariohysterectomy following the use of an absorbable monofilament poliglecaprone 25 suture in 2 different skin closure techniques, the buried continuous subcuticular (BCS) suture pattern and the simple interrupted (SI) suture pattern. These 2 skin closure techniques were evaluated against a nonabsorbable polypropylene monofilament suture in an SI pattern. Wounds were assessed by using a semiquantitative scoring sy...

  19. The Effects of Different Suture Techniques on Wound Healing in Abdominal Wall Closure

    OpenAIRE

    ŞAHİN, Mustafa

    2001-01-01

    Purpose: The aim this study was to investigate the effects of different suture techniques on the healing of abdominal wall wound. Materials and Methods: 24 male Wistar albino rats were included in this study. The rats were divided into two groups. A 4 cm midline laparatomy was performed after ketamine HCl anesthesia. In Group I, the incision was sutured with 4/0 polypropylene interruptedly and in Group II, the wound was closed with 4/0 polypropylene continuously. The skin was sutured with a...

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

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    Jagat Ram

    2013-01-01

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

  1. 15 CFR 10.0 - General.

    Science.gov (United States)

    2010-01-01

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

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

    Science.gov (United States)

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

    1991-05-01

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

  3. GENIE Production Release 2.10.0

    CERN Document Server

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

    2015-01-01

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

  4. Laser division of intraluminal sutures.

    Science.gov (United States)

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

    1998-08-01

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

  5. Radiation treatment of polypropylene

    International Nuclear Information System (INIS)

    Structural changes in polypropylene resulting from high energy electron beam irradiation have been examined. Polymer irradiated in a nitrogen atmosphere is characterized as containing long chain branch structures. A branching index, defined as the ratio of intrinsic viscosity of irradiated polymer to the intrinsic viscosity of linear polymer of equivalent molecular weight, is used to quantify the extent of branching. Polymer crystallization and solution properties undergo significant changes as a result of radiation treatment. Treated polypropylene is highly nucleated. Nucleation density is several orders of magnitude greater than linear polypropylene. Temperature rising elution fractionation (TREF) indicates that the long-chain branched structure contributes to increasing the solubility of polypropylene without greatly reducing the crystallizability and melting point of the solubilized fractions. The presence of long chain branching has a pronounced effect on the polymers extensional rheology in the molten state. Radiation treated polymer exhibits strain hardening elongational viscosity

  6. Releasable suture technique for trabeculectomy

    Directory of Open Access Journals (Sweden)

    Jacob Pushpa

    1993-01-01

    Full Text Available We studied the effect of the releasable suture technique on immediate postoperative intraocular pressure (IOP. Nine eyes of nine patients with glaucoma had trabeculectomy with a releasable suture. In the six eyes that did not receive antimitotics, the suture was released by the fifth postoperative day; in the others suture release was delayed up to the fourteenth day. Of the nine patients, one had an acceptable postoperative IOP and did not need suture release; in another the suture broke and could not be released. In the remaining seven patients, the difference between the pre-release and post-release IOP was statistically significant (p < 0.001. The complications of this technique include failed suture release, subconjunctival hematoma and a distinctive "windshield wiper" keratopathy.

  7. Biodegradation of Polypropylene Nonwovens

    Science.gov (United States)

    Keene, Brandi Nechelle

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

  8. Suturas mecnicas Mechanic sutures

    Directory of Open Access Journals (Sweden)

    Alexandre Miranda Duarte

    2002-10-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  10. Advances in polypropylene based materials

    International Nuclear Information System (INIS)

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

  11. Force sensing in surgical sutures

    OpenAIRE

    Horeman, T.; Meijer, E. J.; Harlaar, J. J.; Lange, J.F.; Van den Dobbelsteen, J.J.; Dankelman, J.

    2013-01-01

    The tension in a suture is an important factor in the process of wound healing. If there is too much tension in the suture, the blood flow is restricted and necrosis can occur. If the tension is too low, the incision opens up and cannot heal properly. The purpose of this paper is to describe the design and evaluation of the Stitch Force (SF) sensor and the Hook-In Force (HIF) sensor. These sensors were developed to measure the force on a tensioned suture inside a closed incision and to measur...

  12. Force sensing in surgical sutures

    OpenAIRE

    Horeman, Tim; Meijer, Evert-jan; Harlaar, Jaap; Lange, Johan; Dobbelsteen, John; Dankelman, Jenny

    2013-01-01

    textabstractThe tension in a suture is an important factor in the process of wound healing. If there is too much tension in the suture, the blood flow is restricted and necrosis can occur. If the tension is too low, the incision opens up and cannot heal properly. The purpose of this paper is to describe the design and evaluation of the Stitch Force (SF) sensor and the Hook-In Force (HIF) sensor. These sensors were developed to measure the force on a tensioned suture inside a closed incision a...

  13. Force Sensing in Surgical Sutures

    OpenAIRE

    2013-01-01

    The tension in a suture is an important factor in the process of wound healing. If there is too much tension in the suture, the blood flow is restricted and necrosis can occur. If the tension is too low, the incision opens up and cannot heal properly. The purpose of this paper is to describe the design and evaluation of the Stitch Force (SF) sensor and the Hook-In Force (HIF) sensor. These sensors were developed to measure the force on a tensioned suture inside a closed incision and to measur...

  14. Craniosynostosis of the Lambdoid Suture

    OpenAIRE

    Rhodes, Jennifer L.; Tye, Gary W.; Fearon, Jeffrey A.

    2014-01-01

    Craniosynostosis affecting the lambdoid suture is uncommon. The definition of lambdoid craniosynostosis solely applies to those cases demonstrating true suture obliteration, similar to other forms of craniosynostosis. In patients presenting with posterior plagiocephaly, true lambdoid craniosynostosis must be differentiated from the much more common positional molding. It can occur in a unilateral form, a bilateral form, or as part of a complex craniosynostosis. In children with craniofacial s...

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

    Directory of Open Access Journals (Sweden)

    Sunita

    2013-11-01

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

  16. Microindentation of oriented polypropylene

    Science.gov (United States)

    Lo, James C. W.

    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.

  17. 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)

  18. 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

  19. 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

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

    LENUS (Irish Health Repository)

    Hennessey, D B

    2012-08-01

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

  1. Unusual sutural bones at pterion

    OpenAIRE

    Nayak SB; Kv, S

    2008-01-01

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

  2. Suture materials - Current and emerging trends.

    Science.gov (United States)

    Dennis, Christopher; Sethu, Swaminathan; Nayak, Sunita; Mohan, Loganathan; Morsi, Yosry Yos; Manivasagam, Geetha

    2016-06-01

    Surgical sutures are used to facilitate closure and healing of surgical- or trauma-induced wounds by upholding tissues together to facilitate healing process. There is a wide range of suture materials for medical purpose and the main types include absorbable and nonabsorbable. Recently, there is a growth in the development of classes of suture materials based on their properties and capabilities to improve tissue approximation and wound closure. This review outlines and discusses the current and emerging trends in suture technology including knotless barbed sutures, antimicrobial sutures, bio-active sutures such as drug-eluting and stem cells seeded sutures, and smart sutures including elastic, and electronic sutures. These newer strategies expand the versatility of sutures from being used as just a physical entity approximating opposing tissues to a more biologically active component enabling delivery of drugs and cells to the desired site with immense application potential in both therapeutics and diagnostics. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1544-1559, 2016. PMID:26860644

  3. Polypropylene: Lowest cost process

    Energy Technology Data Exchange (ETDEWEB)

    Burdett, I.D.

    1986-11-01

    In the past two years, several polypropylene plants have started up using catalysts with sufficient activity and selectivity to obviate the need for separate catalyst residue and atactic polymer removal steps. All these plants, except the UNIPOL PP process, use liquid propylene as the reaction medium. Reaction occurs in a gas-phase medium in the UNIPOL PP process. Gas-phase processes are more versatile than liquid-phase processes. In the liquid-phase the melt flow range is limited by the solubility of hydrogen; carry over a propylene and hydrogen to the second state when making impact copolymers presents significant control problems and limits the range of compositions; and the solubility of the atactic fraction causes crusting on the particle surface during flashoff of the reaction solvent and can deleteriously affect product quality. Moreover, the use of liquid propylene presents a significant potential safety problem due to the presence of large volumes of liquid hydrocarbons. Such problems are quite minimal in the gas-phase processes. Among gas-phase processes, the UNIPOL process is the most simple and economical. There are fewer moving parts and investment costs are recognized to be among the lowest for any polyolefin plant. This article describes the UNIPOL process and illustrates the process and product advantages of the UNIPOL PP over other processes employing high activity catalysts.

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

    International Nuclear Information System (INIS)

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

  5. Lid suture myopia in chicks.

    Science.gov (United States)

    Lauber, J K; Oishi, T

    1987-11-01

    Domestic chicks reared under continuous light developed light-induced avian glaucoma (LIAG), including eye enlargement and flat cornea. Chicks reared under dim light developed dim light buphthalmos (DLB), a somewhat similar eye enlargement, superimposed on the LIAG effect when, as in one subgroup of the present experiments, the dim light was also continuous. Unilateral lid suture elicited experimental myopia on the operated side, additive to the LIAG and/or DLB effects. When the rearing conditions were diurnal (ie, not such as to induce LIAG eye enlargement), and the light of at least "normal" brightness, lid suture still caused unilateral myopia, accompanied by a pronounced bulging of the cornea. We discuss the probable effects of these changes on refraction and accommodation during the chick's development. PMID:3667156

  6. Method for making thin polypropylene film

    Science.gov (United States)

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

    1985-11-21

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

  7. Torrefied biomass-polypropylene composites

    Science.gov (United States)

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

  8. Argon plasma irradiation of polypropylene

    Czech Academy of Sciences Publication Activity Database

    Vasina, A.; Malinský, Petr; Slepička, P.; Macková, Anna; Švorčík, V.

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

  9. Woodflour as Reinforcement of Polypropylene

    Directory of Open Access Journals (Sweden)

    José Cláudio Caraschi

    2002-10-01

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

  10. Changes in mechanical properties of recycled polypropylene.

    OpenAIRE

    Weckström, Dan

    2012-01-01

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

  11. Endoscopic removal of intravesical polypropylene suture with plasmakinetic resection after abdominal hysterectomy

    Directory of Open Access Journals (Sweden)

    Faruk Küçükdurmaz

    2014-01-01

    CONCLUSION: Transurethral resection is the treatment of choice for the removal of intravesical foreign substances. Use of plasmakinetic energy will decrease the risk of complications and avoid the need for open interventions.

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

    Science.gov (United States)

    Gimbel, Howard V; Amritanand, Anika

    2013-12-01

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

  13. Suturing technique for extraocular muscle surgery.

    Science.gov (United States)

    Kraushar, M F; Mercur, L

    1977-10-01

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

  14. Welded polypropylene liners for large descaling tanks

    Science.gov (United States)

    Abel, H. P.

    1971-01-01

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

  15. Laparoscopic fascial suture repair of parastomal hernia

    OpenAIRE

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

    2013-01-01

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

  16. A contact invariant in sutured monopole homology

    OpenAIRE

    Baldwin, John A.; Sivek, Steven

    2014-01-01

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

  17. Argon plasma irradiation of polypropylene

    Czech Academy of Sciences Publication Activity Database

    Slepička, P.; Vasina, A.; Kolská, Z.; Luxbacher, T.; Malinský, Petr; Macková, Anna; Švorčík, V.

    2010-01-01

    Roč. 268, 11-12 (2010), s. 2111-2114. ISSN 0168-583X. [19th International conference on Ion beam analysis. Cambridge, 07.09.2009-11.09.2009] R&D Projects: GA ČR GA106/09/0125; GA MŠk(CZ) LC06041; GA AV ČR(CZ) KAN400480701 Institutional research plan: CEZ:AV0Z10480505 Keywords : Polypropylene * Plasma treatment * RBS Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.042, year: 2010

  18. Massive obstetric haemorrhage following removal of a cervical suture

    OpenAIRE

    Howarth, Louise Ann; Sherliker, Sarah

    2011-01-01

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

  19. Shear lag sutures: Improved suture repair through the use of adhesives.

    Science.gov (United States)

    Linderman, Stephen W; Kormpakis, Ioannis; Gelberman, Richard H; Birman, Victor; Wegst, Ulrike G K; Genin, Guy M; Thomopoulos, Stavros

    2015-09-01

    Suture materials and surgical knot tying techniques have improved dramatically since their first use over five millennia ago. However, the approach remains limited by the ability of the suture to transfer load to tissue at suture anchor points. Here, we predict that adhesive-coated sutures can improve mechanical load transfer beyond the range of performance of existing suture methods, thereby strengthening repairs and decreasing the risk of failure. The mechanical properties of suitable adhesives were identified using a shear lag model. Examination of the design space for an optimal adhesive demonstrated requirements for strong adhesion and low stiffness to maximize the strength of the adhesive-coated suture repair construct. To experimentally assess the model, we evaluated single strands of sutures coated with highly flexible cyanoacrylates (Loctite 4903 and 4902), cyanoacrylate (Loctite QuickTite Instant Adhesive Gel), rubber cement, rubber/gasket adhesive (1300 Scotch-Weld Neoprene High Performance Rubber & Gasket Adhesive), an albumin-glutaraldehyde adhesive (BioGlue), or poly(dopamine). As a clinically relevant proof-of-concept, cyanoacrylate-coated sutures were then used to perform a clinically relevant flexor digitorum tendon repair in cadaver tissue. The repair performed with adhesive-coated suture had significantly higher strength compared to the standard repair without adhesive. Notably, cyanoacrylate provides strong adhesion with high stiffness and brittle behavior, and is therefore not an ideal adhesive for enhancing suture repair. Nevertheless, the improvement in repair properties in a clinically relevant setting, even using a non-ideal adhesive, demonstrates the potential for the proposed approach to improve outcomes for treatments requiring suture fixation. Further study is necessary to develop a strongly adherent, compliant adhesive within the optimal design space described by the model. PMID:26022966

  20. Methods of Retaining the Suture in a Sub-Cuticular Stitch Using Non Absorbable Suture – Innovations and Diversity of Techniques

    OpenAIRE

    Chatterjee, Shamita; Basu, Arghya

    2012-01-01

    Subcuticular sutures have been extensively used for closure of wounds, particularly when good cosmesis is required. Both absorbable and nonabsorbable sutures are used in subcuticular sutures. Nonabsorbable sutures have some distinct advantages over absorbable sutures from cosmetic point of view, when used in subcuticular sutures. The challenge remains in keeping the nonabsorbable suture secure and in situ. We present six different methods of securing the suture in position while closing the w...

  1. Natural Nanotubes Reinforcing Heterophasic Polypropylene

    Scientific Electronic Library Online (English)

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

    2015-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Vitor Mayer de Moura

    2014-06-01

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

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

    OpenAIRE

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

    2001-01-01

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

  4. Acute Airway Obstruction from a Suture Granuloma

    Directory of Open Access Journals (Sweden)

    Jawad Khan

    2010-03-01

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

  5. Flexor Tenorrhaphy Using Absorbable Suture Materials

    Directory of Open Access Journals (Sweden)

    Hyung Joo Kang

    2012-07-01

    Full Text Available Background Nonabsorbable sutures are favorable for repairing flexor tendons. However,absorbable sutures have performed favorably in an animal model.Methods Two-strand sutures using the interlocking modified Kessler method with polydioxanoneabsorbable sutures 4-0 were used to repair completely ruptured flexor tendons in 55 fingersfrom 41 consecutive patients. The medical records of average 42 follow up weeks were analyzedretrospectively. The data analyzed using the chi-squared test, and Fishers 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 Cullens 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.

  6. Medical quality of the radiation resistant polypropylene

    International Nuclear Information System (INIS)

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

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

    LENUS (Irish Health Repository)

    Bonham, Joseph

    2011-06-01

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

  8. The history and evolution of sutures in pelvic surgery

    OpenAIRE

    Muffly, Tyler M; Tizzano, Anthony P; Walters, Mark D

    2011-01-01

    The purpose of the study is to review the history and innovations of sutures used in pelvic surgery. Based on a review of the literature using electronic- and hand-searched databases we identified appropriate articles and gynaecology surgical textbooks regarding suture for wound closure. The first documented uses of suture are explored and then the article focuses on the use of knotted materials in pelvic surgery. The development of suture of natural materials is followed chronologically unti...

  9. Aortic valve annuloplasty: new single suture technique.

    Science.gov (United States)

    Schöllhorn, Joachim; Rylski, Bartosz; Beyersdorf, Friedhelm

    2014-06-01

    Reconstruction strategies for aortic valve insufficiency in the presence of aortic annulus dilatation are usually surgically challenging. We demonstrate a simple, modified Taylor technique of downsizing and stabilization of the aortic annulus using a single internal base suture. Since April 2011, 22 consecutive patients have undergone safe aortic valve annuloplasty. No reoperations for aortic valve insufficiency and no deaths occurred. PMID:24882316

  10. Biomechanical Dynamics of Cranial Sutures during Simulated Impulsive Loading.

    Science.gov (United States)

    Zhang, Z Q; Yang, J L

    2015-01-01

    Background. Cranial sutures are deformable joints between the bones of the skull, bridged by collagen fibres. They function to hold the bones of the skull together while allowing for mechanical stress transmission and deformation. Objective. The aim of this study is to investigate how cranial suture morphology, suture material property, and the arrangement of sutural collagen fibres influence the dynamic responses of the suture and surrounding bone under impulsive loads. Methods. An idealized bone-suture-bone complex was analyzed using a two-dimensional finite element model. A uniform impulsive loading was applied to the complex. Outcome variables of von Mises stress and strain energy were evaluated to characterize the sutures' biomechanical behavior. Results. Parametric studies revealed that the suture strain energy and the patterns of Mises stress in both the suture and surrounding bone were strongly dependent on the suture morphologies. Conclusions. It was concluded that the higher order hierarchical suture morphology, lower suture elastic modulus, and the better collagen fiber orientation must benefit the stress attenuation and energy absorption. PMID:27019589

  11. 21 CFR 878.4830 - Absorbable surgical gut suture.

    Science.gov (United States)

    2010-04-01

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

  12. Elastic behaviour of sutured calf pericardium: influence of the suture threads.

    Science.gov (United States)

    García Páez, J M; Carrera San Martin, A; García Sestafe, J V; Jorge Herrero, E; Navidad, R; Cordón, A; Castillo-Olivares, J L

    1996-09-01

    The purpose of this study was to assess the elastic behaviour of calf pericardium used in the construction of cardiac bioprosthesis valve leaflets, sutured with different types of commercially available sutures: silk, Gore-Tex, Surgilene and nylon. Thirty-two samples (four series of eight samples each) were subjected to tensile strength testing to breakage. The breaking stress (MPa) ranged between 4.89 MPa for samples sutured with Gore-Tex and 5.22 MPa for those sewn with nylon. Three samples from each series were subjected to a stepwise stress test, involving increasing levels of stress followed by return to zero, to define the elastic limit (the cut-off point beyond which strain is no longer reversible). Analysis of the results provided the mathematical functions that govern the elastic behaviour (stress/strain) within the elastic range for each type of sutured sample. The series sutured with Surgilene presented the highest mean value (1.649 MPa). Finally, a statistical study was carried out to determine which series showed the greatest probability of having the least interaction between the thread and the pericardium. Allowing an interval of +/- 10%, Gore-Tex showed the best probability in this respect. However, real fatigue testing is necessary to definitively determine which is the best suture to use. PMID:8866029

  13. 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.

  14. Aksa plans polypropylene joint venture

    International Nuclear Information System (INIS)

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

  15. Horizontal running mattress suture modified with intermittent simple loops

    Directory of Open Access Journals (Sweden)

    Anna H Chacon

    2013-01-01

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

  16. THE ADDITIONAL LOSSES OF THE ELECTRIC POWER IN THE 10/0.4 KV POWER TRANSFORMERS

    OpenAIRE

    Yundin M. A.; Hanin Y. I.

    2014-01-01

    The results of calculation of the constituents of load losses of the electric power in the 10/0.4kV power transformers of the rural household networks of 0.38 kV. Proportions of additional losses of the electric power in the 10/0.4kV power transformers are statistically processed

  17. Cyclic viscoelastoplasticity of polypropylene/nanoclay composites

    DEFF Research Database (Denmark)

    Drozdov, A.; Christiansen, Jesper de Claville

    2012-01-01

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

  18. 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)

  19. Electret Stability Related to Spherulites in Polypropylene

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  20. Permeation of tritiated water through polypropylene

    International Nuclear Information System (INIS)

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

  1. Internal friction studies of particulate filled polypropylene

    International Nuclear Information System (INIS)

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

  2. 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)

  3. A century's worth of arterial sutures.

    Science.gov (United States)

    Barker, W F

    1988-01-01

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

  4. Cranial suture biology of the Aleutian Island inhabitants.

    Science.gov (United States)

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

    2011-04-01

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

  5. Fiber from ramie plant (Boehmeria nivea): A novel suture biomaterial.

    Science.gov (United States)

    Kandimalla, Raghuram; Kalita, Sanjeeb; Choudhury, Bhaswati; Devi, Dipali; Kalita, Dhaneswar; Kalita, Kasturi; Dash, Suvakanta; Kotoky, Jibon

    2016-05-01

    The quest for developing an ideal suture material prompted our interest to develop a novel suture with advantageous characters to market available ones. From natural origin only silk, cotton and linen fibers are presently available in market as non-absorbable suture biomaterials. In this study, we have developed a novel, cost-effective, and biocompatible suture biomaterial from ramie plant, Boehmeria nivea fiber. Field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and thermo gravimetric analysis (TGA) results revealed the physicochemical properties of raw and degummed ramie fiber, where the former one showed desirable characteristics for suture preparation. The braided multifilament ramie suture prepared from degummed fiber exhibited excellent tensile strength. The suture found to be biocompatible towards human erythrocytes and nontoxic to mammalian cells. The fabricated ramie suture exhibited significant antibacterial activity against Escherichia coli, Bacillus subtilis and Staphylococcus aureus; which can be attributed to the inherent bacteriostatic ability of ramie plant fiber. In vivo wound closure efficacy was evaluated in adult male wister rats by suturing the superficial wound incisions. Within seven days of surgery the wound got completely healed leaving no rash and scar. The role of the ramie suture in complete wound healing was supported by the reduced levels of serum inflammatory mediators. Histopathology studies confirmed the wound healing ability of ramie suture, as rapid synthesis of collagen, connective tissue and other skin adnexal structures were observed within seven days of surgery. Tensile properties, biocompatibility and wound closure efficacy of the ramie suture were comparable with market available BMSF suture. The outcome of this study can drive tremendous possibility for the utilization of ramie plant fiber for various biomedical applications. PMID:26952488

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

    International Nuclear Information System (INIS)

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

  7. Polypropylene/aspen/liquid polybutadienes composites

    Czech Academy of Sciences Publication Activity Database

    Kokta, B. V.; Fortelný, Ivan; Kruliš, Zdeněk; Michálková, Danuše

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

  8. Toxicity of pyrolysis gases from polypropylene

    Science.gov (United States)

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

    1979-01-01

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

  9. Plant growth responses to polypropylene--biocontainers

    Science.gov (United States)

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

  10. 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.)

  11. Massive obstetric haemorrhage following removal of a cervical suture.

    Science.gov (United States)

    Howarth, Louise Ann; Sherliker, Sarah

    2011-01-01

    The authors present an unusual case of massive ante partum haemorrhage following removal of a cervical suture. This patient was admitted for routine removal of a McDonald's cervical suture at 37 weeks gestation. The suture was densely adherent and after removal she suffered a haemorrhage of 2500 ml from where the suture was removed which led to fetal distress and an emergency caesarean section. The cervix was sutured and a vaginal pack inserted. During the procedure she developed hypovolaemic shock requiring 7 units of blood, 4 units of fresh frozen plasma, 1 unit of platelets and 1 unit of cryoprecipitate. Ten days later she was readmitted with a postpartum haemorrhage of 1000 ml requiring further haemostatic sutures to the cervix. PMID:22696714

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

    Directory of Open Access Journals (Sweden)

    Kamath B

    2006-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-04-15

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

  14. Radioactive suture in the treatment of head and neck cancer

    International Nuclear Information System (INIS)

    125I seeds in Vicryl suture have been used as a radioactive suture in 24 cases of advanced malignancy of the head and neck. Twelve cases had metastatic carcinoma attached to the internal or common carotid artery. The goal was to excise surgically as much tumor as possible, then implant any residual tumor with this radioactive suture which remains as a permanent implant (half-life of 60 days). This preliminary study shows that use of 125I impregnated Vicryl suture in this manner appears to produce improved long-term palliation and may increase local cure rates

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-10-01

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

  16. Radiation stability of polypropylene/lead zirconate composites

    International Nuclear Information System (INIS)

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

  17. Structural grafts and suture techniques in functional and aesthetic rhinoplasty

    Directory of Open Access Journals (Sweden)

    Gassner, Holger G.

    2010-01-01

    Full Text Available Rhinoplasty has undergone important changes. With the advent of the open structure approach, requirements for structural grafting and direct manipulation of the cartilaginous skeleton through suture techniques have increased substantially. The present review analyzes the current literature on frequently referenced structural grafts and suture techniques. Individual techniques are described and their utility is discussed in light of available studies and data.

  18. Nose tip refinement using interdomal suture in caucasian nose

    Directory of Open Access Journals (Sweden)

    Pasinato, Rogério

    2012-01-01

    Full Text Available Introduction: Refinement of the nose tip can be accomplished by a variety of techniques, but currently, the use of sutures in the nasal tip with conservative resection of the alar cartilage is the most frequently recommended approach. Objective: To classify the nasal tip and to demonstrate the interdomal suture applied to nasal tip refinement in the Caucasian nose, as well as to provide a simple and practical presentation of the surgical steps. Method: Development of surgical algorithm for nasal tip surgery: 1. Interdomal suture (double binding suture, 2. Interdomal suture with alar cartilage weakening (cross-hatching, 3. Interdomal suture with cephalic removal of the alar cartilage (McIndoe technique based on the nasal tip type classification. This classification assesses the interdomal distance (angle of domal divergence and intercrural distance, domal arch width, cartilage consistency, and skin type. Interdomal suture is performed through endonasal rhinoplasty by basic technique without delivery (Converse-Diamond technique under local anesthesia Conclusion: This classification is simple and facilitates the approach of surgical treatment of the nasal tip through interdomal suture, systematizing and standardizing surgical maneuvers for better refinement of the Caucasian nose.

  19. High-resolution sonography of the abnormal cranial suture

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-02-01

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

  20. High-resolution sonography of the abnormal cranial suture

    International Nuclear Information System (INIS)

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

  1. Diffusion of oxygen into irradiated polypropylene films

    International Nuclear Information System (INIS)

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

  2. Viscoelastic properties of vis-breaking polypropylenes

    Science.gov (United States)

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

    2015-12-01

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

  3. 21 CFR 870.3470 - Intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or...

    Science.gov (United States)

    2010-04-01

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

  4. High strain rate behaviour of polypropylene microfoams

    OpenAIRE

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

    2012-01-01

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

  5. Residual stress distribution in extruded polypropylene pipes

    Czech Academy of Sciences Publication Activity Database

    Poduška, Jan; Kučera, J.; Hutař, Pavel; Ševčík, Martin; Křivánek, J.; Sadílek, J.; Náhlík, Luboš

    2014-01-01

    Roč. 2014, č. 40 (2014), s. 88-98. ISSN 0142-9418 R&D Projects: GA ČR(CZ) GAP108/12/1560 Institutional support: RVO:68081723 Keywords : polypropylene * extruded polymer pipe * residual stress * curved beam methodology * numerical simulations Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.240, year: 2014 http://www.sciencedirect.com/science/article/pii/S0142941814001809

  6. Elevated temperature concrete curing - using polypropylene fibres

    OpenAIRE

    Richardson, Alan; Coventry, Kathryn; Morgan, Miles

    2011-01-01

    This paper examines cement hydration when concrete cures at elevated temperatures with and without the addition of Type 1 polypropylene fibres and addresses some of the ambiguities that have arisen from previous research. Paired comparison tests were carried out to compare density, strength, pulse velocity, and absorption using plain and fibre concrete at ambient UK indoor temperatures, compared to concrete at elevated temperatures that would be found in The Middle East. The results ...

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

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

    2013-01-01

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

  9. High strain rate behaviour of polypropylene microfoams

    Science.gov (United States)

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

    2012-08-01

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

  10. High strain rate behaviour of polypropylene microfoams

    Directory of Open Access Journals (Sweden)

    Martínez A.B.

    2012-08-01

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-02-15

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

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

    Science.gov (United States)

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

    2008-02-01

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

  14. Performance of antegrade suture passers according to tendon thickness

    Directory of Open Access Journals (Sweden)

    Myung-Sun Kim

    2015-01-01

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

  15. Radiation cross-linking of montmorillonite/polypropylene composite

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2013-10-01

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

  17. Sutures in the Altaids: Implications for Continental Suturing and Growth (Invited)

    Science.gov (United States)

    Xiao, W.

    2013-12-01

    Ophiolites and melanges are remnants of vanished oceans in orogenic belts; therefore they are very important for defining sutures. However, as illustrated in the Altaids ophiolitic fragments can be formed at different tectonic settings. Some ophiolites in the Altaids may be substrate of oceanic island arcs or accreted fragments, such as those in Kazakhstan and East Junggar. Others are mainly melanges and mostly occur as blocks or slices in accretionary prisms, such as those in the southern Chinese Altay and southern Tianshan. Ages of ophiolites and melanges should be used to constrain the existence time of ancient oceans, which predate the accretionary process after their emplacement. These ophiolitic fragments or melanges do not necessarily represent real sutures. Ages of some ophiolitic fragments and melanges in Central Asia such as those in the Tianshan predate accretion/collision event and the incorporation of these ophiolitic fragments into accretionary complexes may reflect merely different phases of accretion instead of closure of a major ocean. Major oceans or real sutures can only be recognized by paleogeographical separation of typical faunas and/or floras as many orogenic systems contain archipelagos with second-hand ocean basins, a tectonic scenario similar to the present-day SE Asia. Paleomagnetic data and tectonic analysis enable us to conduct palinspastic reconstructions and can help define real sutures, such as the one in the Southern Tianshan as a main cryptic plane separating the Tarim craton to the south and the accretionary collages to the north from the late Paleozoic to the early Triassic. During most of the Paleozoic time, the Siberia Craton was distributed in the northwest and the Tarim Craton was in the southeast, while the Kazakhstan arc chain was in the west. The active margin of the Siberia Craton had wide accretionary complexes and accreted intra-oceanic arcs and terranes, the Kazakhstan arc chain was characterized by multiple subductions, while the northern margin of the Tarim Craton remained mostly a passive margin. The multiple convergence and accretion among these orogenic systems generated huge orogenic collages in the late Paleozoic and even early Triassic, in which two types of amalgamation happened: (1) orthogonal interactions and oroclinal stacking of the Kazakhstan composite arc chain, and (2) parallel collision of the Altai, East Junggar, and Tianshan arcs. Complicated orogensis may shed light on a better understanding of orogenic suturing and continental growth. Acknowledgements: NSFC (41230207, 41190070, 41190075)

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

    OpenAIRE

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

    2009-01-01

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

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

    DEFF Research Database (Denmark)

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

    1999-01-01

    Polypropylene (PP) and polypropylene modified with maleic anhydride (MA-PP) reinforced by continuous longitudinal glass fibres have been investigated. The most prominent effect of the modification with maleic anhydride in the composite is a stronger fibre/matrix interface. The effects of...

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

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt

    2003-01-01

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

  1. Pectin coated hollow fiber polypropylene membranes.

    Science.gov (United States)

    Lewińska, D; Piatkiewicz, W; Rosiński, S

    1997-11-01

    The aim of this study was to prepare a composite membrane for the selective, extracorporeal removal of human LDL-cholesterol. Pectin coated on a porous polypropylene membrane (PP) was used as an active LDL adsorber. Three types of membrane preparations were performed: coating of native PP, coating after chemical etching and gamma-irradiated coated PP. Pectin coated fibers (PCF) were examined under scanning electron microscope (SEM) and tested for hydraulic permeability. As a result of the coating of native and etched PP membrane, pectin layers of various thicknesses (2-16 microm) and porosity were obtained. Irradiation by gamma rays gave no insoluble pectin layers. PMID:9464876

  2. Improvement in the thermal performance of polypropylene

    International Nuclear Information System (INIS)

    In the framework of the CRP our contribution consists of the two directions of investigation on the stabilization of polypropylene: one way follows the compatibilization of the blends of polypropylene with ethylene-propylene terpolymer in the presence of divinylbenzene, and the second way is represented by the nanocomposites polypropylene/calcium carbonate. The irradiation of ethylene-propylene diene terpolymer/polypropylene blends in the presence of divinylbenzene is an alternative procedure, which improves material lifetime and may be applied to material recycling. The selection of these systems is justified on the basis of their capacity on the providing free radicals. The two polymer components, EPDM and PP, can be degraded with various rates because of the different contents of methyl groups. The polymer samples consisted of both materials under various ratios (20:80, 40:60, 60:40 and 80:20); individual materials were also subjected to the action of (137Cs) γ-rays. Divinylbenzene, a hydrocarbon which plays the role of radical source was added iat the level of 5% (w/w). The stabilization effect was tested by two methods: oxygen uptake and IR spectroscopy at the characteristic bands (1720 cm-1 and 3350 cm-1) for carbonyl and hydroxyl groups, respectively. The γ-exposure induced a slower oxidative degradation in the presence of DVB. The carbonyl and hydroxyl indexes were calculated for all formulations. From oxidability investigation the kinetic parameters for thermal oxidation of irradiated samples were calculated. Their modification depicts the radiochemical stability, which is an important feature in the long term applications. The ability of divinylbenzene in the radiation stabilization of studied polyolefin blends is discussed in relation with the modification of exposure dose and sample composition. The irradiation performed in air represents a proper test for the qualification of this polymeric system. Thermal and γ radiation stability of iPP containing CaCO3 nanoparticles were investigated by oxygen uptake procedure at 160oC. The loading of iPP matrix was maximum 25% (w/w). The behaviour on thermal oxidation was investigated for two formulations of iPP compounds differing by the surface characteristics of nanoparticles (i.e. uncoated and stearic acid-coated filler). Three irradiation doses (5, 15 and 25 kGy) were applied. The efficient protection of stabilizers that are present in the as-prepared formulations was emphasized by proper values of the kinetic parameters obtained for oxidation. The contribution of CaCO3 nanoparticles to the oxidative process of iPP is discussed. (author)

  3. The nonlinear viscoelastic behavior of polypropylene

    CERN Document Server

    Drozdov, A D

    2002-01-01

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

  4. Biopolymer synthesis on polypropylene supports: oligonucleotide arrays.

    Science.gov (United States)

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

    1995-01-01

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

  5. A multiphase transitioning peptide hydrogel for suturing ultrasmall vessels

    Science.gov (United States)

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

    2016-01-01

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

  6. Midwives conducting perineal repair: The Danish Suture Trial

    DEFF Research Database (Denmark)

    Kindberg, Sara

    2007-01-01

    Midwives conducting perineal repair: The Danish Suture Trial.     Background Suture techniques and materials for repair of 2nd degree perineal lacerations and episiotomies have been tested in several clinical trials. Danish midwives and obstetricians have developed a new, simple and time......-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...

  7. A new design of a Nitinol ring-like wire for suturing in deep surgical field.

    Science.gov (United States)

    Nespoli, Adelaide; Dallolio, Villiam; Villa, Elena; Passaretti, Francesca

    2015-11-01

    The present work proposes a new suturing procedure based on self-accommodating suture points. Each suture point is made of a commercial NiTi wire hot-shaped in a single loop ring; a standard suture needle is then fixed at one end of the NiTi suture. According to this simple geometry, several NiTi suture stitches have been prepared and tested by tensile test to verify the closing force in comparison to that of commercial sutures. Further experimental tests have also been performed on anatomic samples from animals to verify the handiness of the NiTi suture. Moreover, surface quality of sutures has been carefully investigated via microscopy. Results show that the NiTi suture expresses high stiffness and a good surface quality. In addition, the absence of manual knotting allows for a simple, fast and safe procedure. PMID:26249562

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

    OpenAIRE

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

    1995-01-01

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

  9. Strain in the Braincase and Its Sutures During Function

    OpenAIRE

    Herring, Susan W.; Teng, Shengyi

    2000-01-01

    The skull is distinguished from other parts of the skeleton by its composite construction. The sutures between bony elements provide for interstitial growth of the cranium, but at the same time they alter the transmission of stress and strain through the skull. Strain gages were bonded to the frontal and parietal bones of miniature pigs and across the interfrontal, interparietal and coronal sutures. Strains were recorded 1) during natural mastication in conjunction with electromyographic acti...

  10. Disposable circumcision suture device: clinical effect and patient satisfaction

    OpenAIRE

    Bo-Dong Lv; Shi-Geng Zhang; Xuan-Wen Zhu; Jie Zhang; Gang Chen(Department of Physics, Nanjing University, 22 Hankou Road, Nanjing 210093, P.R. China); Min-Fu Chen; Hong-Liang Shen; Zai-Jun Pei; Zhao-Dian Chen

    2014-01-01

    In our experience patients undergoing circumcision are mostly concerned about pain and penile appearances. We conducted a prospective randomized trial to assess the benefits of a new disposable circumcision suture device (DCSD). A total of 942 patients were equally divided into three groups (conventional circumcision, Shang ring and disposable suture device group). Patients in the DCSD group were anesthetized with compound 5% lidocaine cream, the others with a 2% lidocaine penile block. Opera...

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

    Directory of Open Access Journals (Sweden)

    Swati R Yedke

    2013-01-01

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

  12. SUTURE NON-SUTSRE CIRCUMFERENTIAL REPAIR OF CAROTID ARTERY

    Directory of Open Access Journals (Sweden)

    Jafar Nader

    1969-01-01

    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

  13. Homology cylinders and sutured manifolds for homologically fibered knots

    OpenAIRE

    Goda, Hiroshi; Sakasai, Takuya

    2008-01-01

    Sutured manifolds defined by Gabai are useful in the geometrical study of knots and 3-dimensional manifolds. On the other hand, homology cylinders are in an important position in the recent theory of homology cobordisms of surfaces and finite-type invariants. We study a relationship between them by focusing on sutured manifolds associated with a special class of knots which we call {\\it homologically fibered knots}. Then we use invariants of homology cylinders to give applications to...

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

    Science.gov (United States)

    Muttaqien, Fahdzi; Suprijadi

    2015-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-16

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

  16. Development of braided drug-loaded nanofiber sutures

    International Nuclear Information System (INIS)

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

  17. Development of braided drug-loaded nanofiber sutures

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-08-06

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

  18. Radiation induced grafting of TMPM onto polypropylene

    International Nuclear Information System (INIS)

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

  19. Diffuse reflectance spectrophotometry in polypropylene radiolysis study

    International Nuclear Information System (INIS)

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

  20. Biomechanical characteristics of single-row repair in comparison to double-row repair with consideration of the suture configuration and suture material

    OpenAIRE

    Baums, M.; Buchhorn, G.; Spahn, G.; Poppendieck, B.; Schultz, W; Klinger, H.-M.

    2008-01-01

    The aim of the study was to evaluate the time zero mechanical properties of single- versus double-row configuration for rotator cuff repair in an animal model with consideration of the stitch technique and suture material. Thirty-two fresh-frozen sheep shoulders were randomly assigned to four repair groups: suture anchor single-row repair coupled with (1) braided, nonabsorbable polyester suture sized USP No. 2 (SRAE) or (2) braided polyblend polyethylene suture sized No. 2 (SRAH). The double-...

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

    Directory of Open Access Journals (Sweden)

    NatalinaQuarto

    2011-07-01

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

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

    International Nuclear Information System (INIS)

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

  3. 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

  4. Disposable circumcision suture device: clinical effect and patient satisfaction

    Directory of Open Access Journals (Sweden)

    Bo-Dong Lv

    2014-06-01

    Full Text Available In our experience patients undergoing circumcision are mostly concerned about pain and penile appearances. We conducted a prospective randomized trial to assess the benefits of a new disposable circumcision suture device (DCSD. A total of 942 patients were equally divided into three groups (conventional circumcision, Shang ring and disposable suture device group. Patients in the DCSD group were anesthetized with compound 5% lidocaine cream, the others with a 2% lidocaine penile block. Operation time, intra-operative blood loss, incision healing time, intra-operative and post-operative pain, the penile appearance and overall satisfaction degree were measured. Operation time and intra-operative blood loss were significantly lower in the Shang ring and suture device groups compared to the conventional group (P < 0.001. Intra-operative pain was less in the suture device group compared with the other two groups (P < 0.001; whereas post-operative pain was higher in the conventional group compared to the other two groups (P < 0.001. Patients in the suture device (80.57% and Shang ring (73.57% groups were more satisfied with penile appearances compared with the conventional circumcision group (20.06%, P < 0.05. Patients in suture device group also healed markedly faster than the conventional group (P < 0.01. The overall satisfaction rate was better in the suture device group (78.66% compared with the conventional (47.13% and Shang ring (50.00% groups (P < 0.05. The combination of DCSD and lidocaine cream resulted in shorter operation and incision healing times, reduced intra-operative and post-operative pain and improved patient satisfaction with the cosmetic appearances.

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

    Directory of Open Access Journals (Sweden)

    Campanelli G

    2008-12-01

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

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

    International Nuclear Information System (INIS)

    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 (Ea), 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 13C NMR CP-MAS techniques were used to propose the decomposition mechanism of C4 in the presence of PP.

  7. Mechanical Properties of Nanofilled Polypropylene Composites

    Directory of Open Access Journals (Sweden)

    Cristina-Elisabeta PELIN

    2015-06-01

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

  8. Decontamination of polypropylene fabrics by dry cleaning

    International Nuclear Information System (INIS)

    Polypropylene fabrics can efficiently be decontaminated by dry cleaning in benzine or perchloroethylene, this also in case the fabric was greased in addition to radioactive contamination. For heavily soiled fabric, it is advantageous to first dry clean it and then wash it. The positive effect was confirmed of intensifiers on the cleaning process, especially of benzine soap. In practice, its concentration should be selected within 1 and 10 g.dm-3. Decontamination by dry cleaning and subsequent washing is advantageous in that that the resulting activity of waste water from the laundry is low. Radioactive wastes from the dry cleaning process have a low weight and can be handled as solid waste. (M.D.)

  9. Anisotropic thermal conductivity in sheared polypropylene

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-01-01

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

  10. POLYPROPYLENE/CLAY NANOCOMPOSITES: SYNTHESIS AND CHARACTERIZATION

    Directory of Open Access Journals (Sweden)

    MÓNICA A PÉREZ

    2010-12-01

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

  11. Ionizing radiation effect on Brazilian polypropylene

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2014-03-01

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

  13. 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)

  14. 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

  15. The effects of normal paraffins mobilizers on irradiated polypropylene

    International Nuclear Information System (INIS)

    The n-paraffins blended with polypropylene (PP) as mobilizer had been investigated. The effectiveness of mobilizer (n-paraffins) on irradiated polypropylene is dependent on the molecular weight of mobilizer and its content on polypropylene. The n-docosame (n-C22) possesses the best effectiveness of radiation tolerance on PP among the mobilizer paraffins: n-decane (n-C10), n-hexadecane (n-C16), n-docosane (n-C22) and n-hexatriacontane (n-C36). The 2% (w/w) content of a given mobilizer is the most effective at reducing the embrittlement of irradiated PP as evidenced by the elongation at break. The physical properties of polypropylene with mobilizers such as density, Young's modulus, the Fraction of free volume and the weight swelling ratio in p-xylene at room temperature were measured. Above phenomena are related with the constructive of blended PP and demonstrated by its physical properties

  16. 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

  17. The fire resistance of concrete with polypropylene fibers

    OpenAIRE

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

    2013-01-01

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

  18. Preparation of Polypropylene/Montmorillonite Nanocomposites Using Ionizing Radiation

    International Nuclear Information System (INIS)

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

  19. 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)

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

    OpenAIRE

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

    2013-01-01

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

  1. Radiation resistant modified polypropylene; Polipropylen modyfikowany odporny radiacyjnie

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

  2. Rheometric research of polypropylene Licocene PP2602 melts

    OpenAIRE

    V.V. Romanuke; I.A. Mandzyuk

    2011-01-01

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

  3. Synthesis of Polypropylene Fiber/Hydrated Iron Oxide Nanocomposite Adsorbent

    OpenAIRE

    Bondar I.V.; Kuzenko S.V.; Han D.H.; Cho H.K.

    2013-01-01

    Composite adsorbent based on the polypropylene fibers with chemically bound nanoparticles of hydrated iron (III) oxide were synthesized by two-stage experiment: radiation-induced graft polymerization of acrylic acid onto the surface of polypropylene fibers followed by the in-situ formation of hydrated iron oxide nanoparticles and their stabilization on the fibers’ surface within the grafted layer. SEM and XRD investigations revealed a compact homogeneous layer of amorphous nanoaggregates (70-...

  4. Total laparoscopic hysterectomy via suture and ligation technique

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Nagaraju

    2015-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Elif Sarı

    2014-12-01

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

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

    International Nuclear Information System (INIS)

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

  8. Dimensionally-reduced sutured Floer homology as a string homology

    OpenAIRE

    Mathews, Daniel V.; Schoenfeld, Eric

    2012-01-01

    We show that the sutured Floer homology of a sutured 3-manifold of the form $(D^2 \\times S^1, F \\times S^1)$ can be expressed as the homology of a string-type complex, generated by certain sets of curves on $(D^2, F)$ and with a differential given by resolving crossings. We also give some generalisations of this isomorphism, computing "hat" and "infinity" versions of this string homology. In addition to giving interesting elementary facts about the algebra of curves on surfaces, these isomorp...

  9. A Study of the Efficacy of Antibacterial Sutures for Surgical Site Infection: A Retrospective Controlled Trial

    OpenAIRE

    HOSHINO, SEIICHIRO; YOSHIDA, YOICHIRO; Tanimura, Syu; Yamauchi, Yasushi; Noritomi, Tomoaki; Yamashita, Yuichi

    2013-01-01

    To reduce bacterial adherence to surgical sutures, triclosan-coated polyglactin 910 suture materials with antiseptic activity were developed. The aim of this study was to evaluate whether the incidence of surgical site infections can be reduced when triclosan-coated sutures are used. Until December 2009, we used conventional polyglactin 910 sutures (VICRYL, Ethicon) for the closure of the fascia in digestive tract surgery. Therefore, for the control group we retrospectively collected surveill...

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

    OpenAIRE

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

    2013-01-01

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

  11. Chemical imaging of wood-polypropylene composites.

    Science.gov (United States)

    Harper, David P; Wolcott, Michael P

    2006-08-01

    Recent investigations of wood plastic composites have revealed a detrimental effect of using lubricant systems in production. This includes nullifying part or all of the mechanical benefit of using a polar compatibilizer, maleic anhydride polypropylene (MAPP), in the composite formulation. This investigation utilizes lubricants labeled with deuterium in conjunction with Fourier transform infrared (FT-IR) spectroscopy to allow for the separation of individual lubricants from all other material constituents. All of the deuterium labeled lubricants, used without MAPP, revealed their expulsion from the wood interface during crystallization. MAPP coupling agent was found to exist near the wood, but it is unclear if any covalent bonding with the hydroxyl functionality on the wood surface occurred. The addition of zinc stearate lubricants appears to nullify the activity of the anhydride functionality near the wood surface as evidenced by a shift in the FT-IR spectra to the hydrolyzed form of the coupling agent. Most of the additives collect at the edges of the spherulites in mostly amorphous regions of the material. The consequence of this morphology may be a weak interface between crystallites. PMID:16925926

  12. Radiation Effects on Polypropylene Carbon Nanofibers

    Science.gov (United States)

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

    2010-03-01

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

  13. Microwave Irradiation on Halloysite-Polypropylene Nanocomposites

    Science.gov (United States)

    Espino, Omar; Yust, Brian; Chipara, Dorina; Ajayan, Pullickel; Chipara, Alin; Chipara, Mircea; Utrgv Collaboration; Rice Collaboration

    Halloysite is an unique cyllindrical nanoclay characterized by poor electrical and thermal conductivity, which may become the filler of choice for the reinforcement of polymeric matrix, where electrical or thermal insulation are required. The main limits in the use of halloysite as replacement for carbon nanotube (CNT) are: 1. Smaller aspect ratio as halloysites are typically shorter than CNTs. 2. Smaller Young modulus of halloysites compared with CNTs. 3. Reduced thermal stability due to the loss of water upon heating. A research on halloysite dispersed within isotactic polypropylene is reported. To improve the interface between the halloysite and the polymeric matrix a microwave irradiation step has been considered. The local heating of the halloysite nanotubes is mediated by the absorbed/structural water content of the nanoclay. Nanocomposites loaded by various amounts of halloysite ranging from 0 % to 20 % wt. have been prepared by melt mixing by using a Haake RheoMixer. The as obtained nanocomposites have been subjected to microwave irradiation at 75 W in an Anton Paar Monowave 300 system and various irradiation times ranging from 5, 10, 15, 30, 45, and 60 minutes. The effect of microwave irradiation has been studied by Raman and FTIR spectroscopy

  14. Post-irradiation degradation of polypropylene

    International Nuclear Information System (INIS)

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

  15. Electrical properties of ion irradiated polypropylene films

    Indian Academy of Sciences (India)

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

    2004-06-01

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

  16. Cytology of suture granuloma in a recurrent thyroid nodule

    Directory of Open Access Journals (Sweden)

    G. J. Vani Padmaja

    2014-02-01

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

  17. An absorbable thread suture technique to treat snoring.

    Science.gov (United States)

    Kwon, Jang-Woo; Kong, Tae-Hoon; Ha, Tae-Hyoung; Park, Dong-Joon

    2016-05-01

    We investigated a novel, minimally invasive surgery that uses an absorbable suture technique to treat snoring and mild obstructive sleep apnea. This simple procedure was developed to increase the stiffness of the soft palate and to promote uvula elevation with sutures. Thirty-five snorer and mild obstructive sleep apnea syndrome patients were included in this study. The palate was sutured with the newly developed technique. The results of our surgery were evaluated using polysomnography (PSG), the Epworth sleepiness scale (ESS), and a visual analogue scale (VAS) before surgery and 90 days after surgery. One year after surgery, telephone interviews were performed to assess patient satisfaction. Postoperative physical examinations of all patients showed increased stiffness of the soft palate and superiorly displaced uvula. These findings were consistent after the postoperative day 90. The patients' snoring symptoms and their bed partners' complaints, assessed by ESS and VAS, significantly improved compared to the pre-treatment value (p PSG, was significantly improved compared to the pre-treatment value (p < 0.05). Based on the results from the telephone interviews analyzed 1 year after surgery, about 88 % of patients were satisfied with the outcome. This minimally invasive snoreplasty that uses absorbable suture material is an effective and simple procedure for treating snoring and mild obstructive sleep apnea. PMID:26162452

  18. Suture-Related Keratitis Caused by Corynebacterium macginleyi▿

    OpenAIRE

    SUZUKI, TAKASHI; Iihara, Hirotoshi; Uno, Toshihiko; HARA, Yuko; Ohkusu, Kiyofumi; Hata, Hiroyuki; Shudo, Masachika; Ohashi, Yuichi

    2007-01-01

    We report two cases of suture-related keratitis following penetrating keratoplasty. In both cases, Corynebacterium macginleyi was isolated from corneal specimens. Scanning electron microscopy revealed that corynebacteria could aggregate and form a biofilm. The MICs of sulbenicillin and fluoroquinolones were high for both isolates. Our findings show that C. macginleyi can cause keratitis with biofilm formation.

  19. 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

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

    Directory of Open Access Journals (Sweden)

    Zaichenko A.A.

    2011-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Bhatti S

    1996-01-01

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

  2. Automatic Detection of Wild-type Mouse Cranial Sutures

    DEFF Research Database (Denmark)

    Ólafsdóttir, Hildur; Darvann, Tron Andre; Hermann, Nuno V.; Ersbøll, Bjarne Kjær; Oubel, Estanislao; Larsen, Rasmus; Frangi, Alejandro F.; Larsen, Per; Perlyn, Chad A.; Morriss-Kay, Gillian M.; Kreiborg, Sven

    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...

  3. Probing electrical conductivity of the Trans-European Suture Zone

    Czech Academy of Sciences Publication Activity Database

    Brasse, H.; Červ, Václav; Ernst, T.; Hoffmann, N.; Jankowski, J.; Józwiak, W.; Korja, T.; Kreutzmann, A.; Neska, A.; Palshin, N.; Pedersen, L. B.; Schwarz, G.; Smirnov, M.; Sokolova, E.; Varentsov, I. M.

    2006-01-01

    Roč. 87, č. 29 (2006), 281, 287. ISSN 0096-3941 R&D Projects: GA ČR GA205/04/0740 Institutional research plan: CEZ:AV0Z30120515 Keywords : electrical conductivity * Trans-European Suture Zone * EMTESZ-Pomerania Subject RIV: DE - Earth Magnetism, Geodesy, Geography

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

    International Nuclear Information System (INIS)

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

  5. The optimal timing of suture removal depends on the anatomical location

    DEFF Research Database (Denmark)

    JK Stubsgaard, Antje; Andresen, Kristoffer; Rosenberg, Jacob

    2015-01-01

    The objective of this article was to review current recommendations about the optimal timing of suture removal for percutaneous, non-absorbable sutures in surgical incisions and traumatic wounds. A review of relevant literature showed that the recommendations for timing of suture removal varied i...

  6. Brief communication: age and fractal dimensions of human sagittal and coronal sutures

    DEFF Research Database (Denmark)

    Lynnerup, Niels; Jacobsen, Jens Christian Brings

    2003-01-01

    The fractal dimensions of human sagittal and coronal sutures were calculated on 31 complete skulls from the Terry Collection. The aim was to investigate whether the fractal dimension, relying on the whole sutural length, might yield a better description of age-related changes in sutural morphology...

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

    Directory of Open Access Journals (Sweden)

    P.S.M. Megat-Yusoff

    2013-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  12. Effects of Citalopram on Sutural and Calvarial Cell Processes

    Science.gov (United States)

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

    2015-01-01

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

  13. Production of high melt strength polypropylene by gamma irradiation

    Science.gov (United States)

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

    2007-11-01

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

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

    OpenAIRE

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

    2006-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Morris C Phillip

    2007-12-01

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

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

    Directory of Open Access Journals (Sweden)

    F Maldonado

    2006-01-01

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

  17. Surface and mechanical properties of polypropylene/clay nanocomposite

    Directory of Open Access Journals (Sweden)

    Dibaei Asl Husein

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Wang Kui

    2015-01-01

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

  19. Antioxidant action in irradiated polypropylene studied by ultraviolet spectroscopy

    International Nuclear Information System (INIS)

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

  20. Gamma radiation resistance of tale-polypropylene composite materials

    International Nuclear Information System (INIS)

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

  1. Properties of antibacterial polypropylene/nanometal composite fibers.

    Science.gov (United States)

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

    2012-01-01

    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

  2. Reinforcement of Recycled Foamed Asphalt Using Short Polypropylene Fibers

    OpenAIRE

    Yongjoo Kim; Tae-Soon Park

    2013-01-01

    This paper presents the reinforcing effects of the inclusion of short polypropylene fibers on recycled foamed asphalt (RFA) mixture. Short polypropylene fibers of 10 mm length with a 0.15% by weight mixing ratio of the fiber to the asphalt binder were used. The Marshall stability test, the indirect tensile strength test, the resilient modulus test, and wheel tracking test of the RFA mixtures were conducted. The test results were compared to find out the reinforcing effects of the inclusion of...

  3. Investigation into effects of environmental radiation on polypropylene bags

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Fernandes MA

    2014-02-01

    Full Text Available Marcos AP Fernandes,1 Bruno MT Pereira,2 Sandra M Guimares,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, So Paulo, Brazil; 3Laboratrio de Patologia Micron Cell Diagnstico, 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

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

    Directory of Open Access Journals (Sweden)

    M. T. T. Braga

    2000-01-01

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

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

    International Nuclear Information System (INIS)

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

  7. Suture contamination by surface powders on surgical gloves.

    Science.gov (United States)

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

    1983-06-01

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

  8. Local Delivery of Growth Factors Using Coated Suture Material

    OpenAIRE

    T. F. Fuchs; C. Surke; Stange, R. (Richard); S. Quandte; Wildemann, B; Raschke, M. J.; Schmidmaier, G.

    2012-01-01

    The optimization of healing processes in a wide range of tissues represents a central point for surgical research. One approach is to stimulate healing processes with growth factors. These substances have a short half-life and therefore it seems useful to administer these substances locally rather than systemically. One possible method of local delivery is to incorporate growth factors into a bioabsorbable poly (D, L-lactide) suspension (PDLLA) and coat suture material. The aim of the present...

  9. Facial Asymmetry Correction in Facial Palsy Patients with Silhouette Sutures

    OpenAIRE

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

    2012-01-01

    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 ...

  10. Comparison of Subcuticular Suture Materials in Cesarean Skin Closure

    OpenAIRE

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

    2015-01-01

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

  11. Visual Measurement of Suture Strain for Robotic Surgery

    OpenAIRE

    Young Soo Park; John Martell; Thomas Elmer; Nachappa Gopalsami

    2011-01-01

    Minimally invasive surgical procedures offer advantages of smaller incisions, decreased hospital length of stay, and rapid postoperative recovery to the patient. Surgical robots improve access and visualization intraoperatively and have expanded the indications for minimally invasive procedures. A limitation of the DaVinci surgical robot is a lack of sensory feedback to the operative surgeon. Experienced robotic surgeons use visual interpretation of tissue and suture deformation as a surrogat...

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

    Directory of Open Access Journals (Sweden)

    M.E. Latronico

    2012-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Bahareh Kalantari

    2012-01-01

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

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

    Scientific Electronic Library Online (English)

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

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

  15. Polypropylene nanocomposites: effect of coupling agent on structure and properties

    Czech Academy of Sciences Publication Activity Database

    Kotek, Jiří; Kelnar, Ivan; Studenovský, Martin

    Dresden : Max Planck Institute for the Physic of Complex Systems, 2005. [MPG-MOEL– Symposium: Science and Art in Europe, Polymers: Materials in Nature and in Advanced Technologies. 23.5.2005-25.5.2005, Dresden] R&D Projects: GA AV ČR(CZ) IBS4050351 Keywords : polypropylene * nanocomposites * melt-compounding Subject RIV: CD - Macromolecular Chemistry

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  17. [INFLUENCE OF TITANIUM COATING ON THE BIOCOMPATIBILITY OF POLYPROPYLENE IMPLANTS].

    Science.gov (United States)

    Babichenko, I I; Kazantsev, A A; Titarov, D L; Shemyatovsky, K A; Ghevondian, N M; Melchenko, D; Alekhin, A I

    2016-01-01

    Comparative analysis of the proliferative activity of inflammatory cells and distribution of collagen types I and III was carried out around the net materials of polypropylene and titanium coating polypropylene using im- munohistochemical method and polarization microscopy. Experimental modeling of implanted mesh material were made in the soft tissues of the lumbar region of rats. On the 7th postoperative day, quantitative analysis of proliferating cells delected using antibodies to the Ki-67 protein showed, a significant decrease (p types of collagen fibers in the granulomas around various types of implanted mesh material were detected on sections stained with Sirius red at polarizing light. On the 7th day after surgery, the ratio of collagen fibers ty- pe I and III in granulomas around the mesh material made of polypropylene was 1.085 ± 0.022 and this rati around materials of titanium coated polypropylene was higher--1.107 ± 0.013 (p = 0.017). On the 30th posto- perative day in the interface area ratio I/III collagen significantly increased and amounted to 1.174 ± 0.036 and 1.246 ± 0.102, respectively (p = 0.045). Assessing the impact of the use of titanium as a coating on the po- lypropylene, it can be argued that it promotes the formation of collagen I type and a more mature connective tis- sue around the mesh of the implants. PMID:27220251

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Emiliana Rose Jusoh,

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mirković Siniša

    2011-01-01

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

  1. 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)

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

    OpenAIRE

    NatalinaQuarto

    2011-01-01

    Craniosynostosis, the premature closure of cranial suture, is a pathologic condition that affects 1/2000 live births. Saethre-Chotzen syndrome is a genetic condition characterized by craniosynostosis. The Saethre-Chotzen syndrome, which is defined by loss-of-function mutations in the TWIST gene, is the second most prevalent craniosynostosis. Although much of the genetics and phenotypes in craniosynostosis syndromes is understood, less is known about the underlying ossification mechanism durin...

  3. Rheometric research of polypropylene Licocene PP2602 melts

    Directory of Open Access Journals (Sweden)

    V.V. Romanuke

    2011-07-01

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

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

    OpenAIRE

    Thomassin, Jean-Michel; Huynen, Isabelle; Jérôme, Robert; Detrembleur, Christophe

    2010-01-01

    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 (

  5. 2-hydroxyethyl methacrylate composite - polypropylene mesh for preventing peritoneal adhesions in female dogs Compósito 2-hidroxietil dimetacrilato-tela de polipropileno para prevenção de aderências peritoneais em cadelas

    Directory of Open Access Journals (Sweden)

    Marcelo Seixo de Brito e Silva

    2010-08-01

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

  6. 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)

  7. Bilateral squamosal suture synostosis: A rare form of isolated craniosynostosis in Crouzon syndrome

    OpenAIRE

    Tandon, Yasmeen K; Rubin, Michael; Kahlifa, Mohamed; Doumit, Gaby; Naffaa, Lena

    2014-01-01

    Craniosynostosis is a pathologic condition which is characterized by the premature fusion of cranial sutures. It may occur alone or in association with other anomalies making up various syndromes. Crouzon syndrome is the most common craniosynostosis syndrome. Bicoronal sutures fusion is most commonly involved in Crouzon syndrome. There have only been a handful of cases of squamosal suture synostosis described in the surgery literature with the few ones described in Crouzon syndrome associated...

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

    OpenAIRE

    Baldwin, John A.; Sivek, Steven

    2016-01-01

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

  9. Complications of suture ligation ablation for ulnar polydactyly: a report of two cases

    OpenAIRE

    Patillo, Dominic; Rayan, Ghazi M.

    2010-01-01

    We report two cases resulting in complications following suture ligation treatment for ulnar polydactyly. One case consisted of bilateral, retained gangrene and cellulitis, and a second case consisted of a residual, sensitive skin tag. The case involving gangrene and cellulitis developed after an unsuccessful suture ligation of bilateral pedunculated duplicated digits. The second case developed after suture ligature ablation of a rudimentary digit in the nursery but presented 3 years later wi...

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

    Science.gov (United States)

    Abdelwahab, Mohamed; Misra, Manjusri; Mohanty, Amar

    2015-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Chien-Lin Huang

    2015-11-01

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

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

    OpenAIRE

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

    2014-01-01

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

  13. Microarterial anastomoses: A parameterised computational study examining the effect of suture position on intravascular blood flow.

    Science.gov (United States)

    Wain, R A J; Hammond, D; McPhillips, M; Whitty, J P M; Ahmed, W

    2016-05-01

    This study investigates the extent to which individual aspects of suture placement influence local haemodynamics within microarterial anastomoses. An attempt to physically quantify flow characteristics of blood past microvascular sutures is made using computational fluid dynamics (CFD) software. Particular focus has been placed on increased shear strain rate (SSR), a known precipitant of intravascular platelet activation and thrombosis. Measurements were taken from micrographs of sutured anastomoses in chicken femoral vessels, with each assessed for bite width, suture angle and suture spacing. Computational geometries were then created to represent the anastomosis. Each suture characteristic was parameterised to allow independent or simultaneous adjustment. Flow rates were obtained from anonymised Doppler ultrasound scans of analogous vessels during preoperative assessment for autologous breast reconstruction. Vessel simulations were performed in 2.5mm ducts with blood as the working fluid. Vessel walls were non-compliant and a continuous Newtonian flow was applied, in accordance with current literature. Suture bite angle and spacing had significant effects on local haemodynamics, causing notably higher local SSRs, when simulated at extremes of surgical practice. A combined simulation, encompassing subtle changes of each suture parameter simultaneously i.e. representing optimum technique, created a more favourable SSR profile. As such, haemodynamic changes associated with optimum suture placement are unlikely to influence thrombus formation significantly. These findings support adherence to the basic principles of good microsurgical practice. PMID:26876115

  14. 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

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

    Directory of Open Access Journals (Sweden)

    Shahla Kakoei

    2010-06-01

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

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

    LENUS (Irish Health Repository)

    Tiong, William H C

    2011-09-01

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

  17. Biologic response to orthopedic sutures: a histologic study in a rabbit model.

    Science.gov (United States)

    Carr, Brian J; Ochoa, Leah; Rankin, David; Owens, Brett D

    2009-11-01

    Biologic reactivity to suture materials can have an effect on patient outcomes. The goal of this study was to determine the histologic response to 8 commonly used orthopedic sutures--Ethibond (Ethicon, Somerville, New Jersey), Ticron (Tyco, Waltham, Massachusetts), HiFi (Linvatec, Largo, Florida), Ultrabraid (Smith & Nephew, Memphis, Tennessee), MaxBraid (Biomet, Warsaw, Indiana), Orthocord (Mitek, Raynham, Massachusetts), MagnumWire (Opus Medical, San Juan Capistrano, California), and FiberWire (Arthrex, Naples, Florida)--using a rabbit model. The suture granuloms were evaluated at 30, 60, and 120 days with measurement of the fibrous capsule, the number of giant cells in and near the capsule, and the overall inflammatory grade: 1 (mild), 2 (moderate), and 3 (severe). MagnumWire and Ticron sutures initiated a more intense inflammatory reaction when compared to the other sutures. By 120 days, MagnumWire (P=.0297) and Ticron (P=.1855) had fewer giant cells at the soft tissue-suture interface, fewer giant cells within the capsule (P=.0074 and P=.0377, respectively), and the greatest capsular thickness of all suture types (P<.0001 and P=.1378, respectively). Differences exist between the biologic reactivity of commonly used orthopedic sutures that may be attributable to their material composition and/or braid characteristics. In comparison to other high-strength sutures, MagnumWire and Ticron stimulated a more intense foreign body inflammatory response. PMID:19902886

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

    International Nuclear Information System (INIS)

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

  19. Effectivity of intraoperative adjustable suture technique in horizontal strabismus

    Directory of Open Access Journals (Sweden)

    Ayse Gul Kocak Altintas

    2013-08-01

    Full Text Available AIM:To compare the long-term effectivity of intraoperative adjustable suture technique with traditional non-adjustable strabismus surgery.METHODS:Two hundred and thirty-three patients, who underwent strabismus surgery either with traditional procedures or one-stage intraoperative adjustable suture technique, were included in our long-term follow-up study. One hundred and eighteen patients were evaluated in traditional surgery group (TSG and 115 who underwent adjustable suture were in the one-stage intraoperative adjustable surgery group (ASG. In this group 9 patients had paralytic strabismus and 16 had reoperations, 2 patients had restrictive strabismus related to thyroid eye disease. The mean follow up in the TSG was 26.2 months and it was 24.8 months in the ASG group.RESULTS:In patients with exotropia (XT the mean correction of deviation for near fixation in ASG (32.413.2PD and in TSG (26.48.2PD were similar (P=0.112. The correction for distant fixation in ASG (33.211.4PD and TSG (30.97.2PD were not significantly different (P=0.321. In patients with esotropia (ET even the mean correction of deviation for both near (3112PD and distant (30.612.8PD fixations were higher in ASG than in TSG, for both near (28.2714.2PD and distant (28.912.9PD 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.

  20. Barbed Suture as a Treatment Approach in Complex Degloving Injuries.

    Science.gov (United States)

    Boudreault, David Jean-Guy; Lance, Sam H; Garcia, Jesus A

    2016-05-01

    In the late19th century, French physician Morel-Lavallée was challenged with a group of patients who sustained similar patterns of degloving injuries, which today carry his eponym. In 1853, he reported a series of cases as well as proposed strategies for the management of these complex degloving injuries. Treatment strategies have not varied significantly over the years, and these lesions continue to plague surgeons today with failure rates in excess of 50%. We present 2 case series using barbed suture in the management of these complex injuries. PMID:26954732

  1. Surface characterization of plasma-treated polypropylene fibers

    International Nuclear Information System (INIS)

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

  2. 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)

  3. 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 γ 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

  4. Study of blends based on polypropylene and Epdm elastomer

    International Nuclear Information System (INIS)

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

  5. Determination of physicochemical changes in ion beam irradiated polypropylene

    International Nuclear Information System (INIS)

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

  6. Carbon ion irradiation induced surface modification of polypropylene

    International Nuclear Information System (INIS)

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

  7. 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

  8. Mechanical properties of pineapple leaf fibre reinforced polypropylene composites

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

  9. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-15

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

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

    Directory of Open Access Journals (Sweden)

    João C. Miguez Suarez

    2005-06-01

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2015-10-14

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

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

    Science.gov (United States)

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

    2010-08-01

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

  15. Multifunctional nanocomposite foams based on polypropylene with carbon nanofillers

    OpenAIRE

    Sousa Pais Antunes, Marcelo de; Gedler, Gabriel; Velasco Perero, José Ignacio

    2013-01-01

    This work considers the preparation and characterization of polypropylene foams with variable concentrations of graphene and carbon nanofibres, focussing on the influence of the foaming process and the nanofillers on the microstructural and dynamic-mechanical- thermal properties of the foams. Great differences were found in terms of foam morphology depending on the type of foaming process, with foams prepared by physical foaming showing a vertically deformed cell structure, whi...

  16. Study of the properties of polypropylene-PHB blends

    OpenAIRE

    García Quesada, Juan Carlos; Marcilla Gomis, Antonio; Barreiro Ortiz, Patricia; Gil Boj, Erika; López Pastor, Miriam

    2007-01-01

    Polypropylene is ,with PVC and polyethylene, one of the most employed polymers for the production of daily life items. Although it is a thermoplastic polymer and nowadays the recycling conscience of the society is increasing, it is still found in urban wastes and therefore in landfills. Then, the main disadvantage is the permanence and the long life time of this type of plastics. The addition of biodegradable polymers has been claimed as a way to palliate this problem, since with degradation ...

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

    OpenAIRE

    Martin Bajus; Elena Hjekov; Helena Jurdkov; Robert Kubinec; Ladislav Sojk

    2006-01-01

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

  18. Hydroperoxide titration by DSC in thermally oxidized polypropylene

    OpenAIRE

    Richaud, E.; Farcas, F.; FAYOLLE, B.; AUDOUIN, L; Verdu, J.

    2006-01-01

    Unstabilized polypropylene (PP) films and stabilized PP fibres were thermally oxidized at 80 °C under high oxygen pressure (5.0 MPa). Their oxidation was monitored by infrared (IR) spectroscopy, iodometric titration and modulated differential scanning calorimetry (MDSC). This latter technique allows separation of the thermograms into two parts: a reversing signal containing the major part of the melting endotherm and a non-reversing exothermal signal increasing with hydroperoxide amount conta...

  19. Aqueous Processes for Dyeing Generic, Unmodified Polypropylene Fiber

    OpenAIRE

    Murari L. Gupta; Fred Cook

    2010-01-01

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

  20. 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)

  1. Structure of polypropylene parts from multicavity injection mould

    OpenAIRE

    E. Bociąga; T. Jaruga

    2007-01-01

    Purpose: The examination of structure of injection moulded parts, coming form different cavities of injection mould with geometrically balanced runners, was the purpose of this research. The parts were manufactured from polypropylene.Design/methodology/approach: The method of optical microscopy was used. The samples were prepared from microtomed slices from parts and next they were observed in polarized light. The skin-core morphology was analyzed and spherulitic structure was described by sp...

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

    Energy Technology Data Exchange (ETDEWEB)

    Abednejad, Atiye Sadat, E-mail: atiyeabednejad@gmail.com [Department of Biomedical Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran (Iran, Islamic Republic of); Amoabediny, Ghasem [Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran (Iran, Islamic Republic of); Research Center for New Technologies in Life Science Engineering, University of Tehran, P.O. Box 63894-14179, Tehran (Iran, Islamic Republic of); Ghaee, Azadeh [Department of Biomedical Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran (Iran, Islamic Republic of)

    2014-09-01

    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 H{sub 2} and O{sub 2} plasma, membrane immersion in polyethylene glycol (PEG) and plasma graft polymerization was performed. The membranes were characterized by contact angle measurement, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), tensile test, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Oxygen transfer of modified membranes was also tested. The stability of grafted PEG was measured in water and in phosphate buffer saline (PBS) at 37 °C. Blood compatibility of modified surfaces was evaluated by the platelet adhesion method. Water contact angel reduction from 110° to 72° demonstrates the enhanced hydrophilicity, and XPS results verify the presence of oxygenated functional groups due to the peak existence in 286 eV as a result of PEG grafting. The results clearly indicate that plasma graft-polymerization of PEG is an effective way for antifouling improvement of polypropylene membranes. Also, the results show that oxygen transfer changes in PEG grafted membranes are not significant. - Highlights: • H{sub 2} and O{sub 2} plasma graft polymerization of PEG on polypropylene membrane was carried out. • Changes in surface properties were investigated by FTIR, XPS, SEM, and AFM. • Surface wettability enhanced as a result of poly ethylene glycol grafting. • PEG grafting degree increase causes reduction of fouling and adhesion.

  3. Effect of Polypropylene Fiber on Properties of Concrete

    OpenAIRE

    Vinay Kumar Singh

    2014-01-01

    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 f...

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

    OpenAIRE

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

    2007-01-01

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

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

    International Nuclear Information System (INIS)

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

  6. Bacterial Growth on Chitosan-Coated Polypropylene Textile

    OpenAIRE

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

    2012-01-01

    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...

  7. Microstructure and mechanical properties of Polypropylene/Polycarbonate blends

    OpenAIRE

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

    2008-01-01

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

  8. Fracture toughness of injection moulded organoclay reinforced polypropylene composites

    OpenAIRE

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

    2010-01-01

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

  9. Fracture Toughness of Polypropylene-Based Particulate Composites

    OpenAIRE

    David Arencn; Jos Ignacio Velasco

    2009-01-01

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

  10. Influence of MWNT on polypropylene and polyethylene photooxidation

    OpenAIRE

    Bocchini, Sergio; Frache, Alberto; Di Blasio, Alessandro

    2011-01-01

    Nanocomposites containing multiwall carbon nanotubes (MWNT) were prepared by melt compounding with polypropylene and polyethylene. The samples were UV-light irradiated in artificial accelerated conditions representative of solar irradiation (l>300 nm) at 60 °C in air. The chemical modifications resulting from photooxidation were followed by FT-IR spectroscopy. The behaviour of nanocomposites containing MWNT depends from the type of polymer and presence or absence of antioxidant. The presence ...

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

    OpenAIRE

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

    2014-01-01

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

  12. Constructional materials based on cross-linked polypropylene reinforced by modified basalt fibers

    OpenAIRE

    Chervakov, Denys; Bashtanyk, Petro; Burmistr, Mihail

    2011-01-01

    Technology of polymer materials production based on polypropylene reinforced by modified basalt fibers has been obtained. The experimental results of polypropylene modification by benzoyl peroxides and mixture of benzoyl peroxide with methylvinylcyclosiloxane on mechanical properties of composite material have been shown. It has been established that composite materials based on crosslinked polypropylene reinforced by basalt fibers which are dressed by polyepichlorohydrin resins have the incr...

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

    OpenAIRE

    Myrtha Karina; Holia Onggo; Anung Syampurwadi

    2007-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Kaye, Kai O.

    2014-12-01

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

  15. Suture of a stab wound of the heart.

    Science.gov (United States)

    Ellis, Harold

    2015-01-01

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

  16. 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)

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

    Directory of Open Access Journals (Sweden)

    A. Kmetty

    2013-02-01

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

  18. Nanocomposites of irradiated polypropylene with clay are degradable?

    Science.gov (United States)

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

    2016-01-01

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

  19. Rheological study of polypropylene irradiated with polyfunctional monomers

    Energy Technology Data Exchange (ETDEWEB)

    Otaguro, H.; Rogero, S.O.; Yoshiga, A.; Lima, L.F.C.P.; Parra, D.F. [IPEN/CNEN - Instituto de Pesquisas Energeticas e Nucleares, Av. Professor Lineu Prestes, 2242, CEP 05508-000 - Cidade Universitaria, Sao Paulo, SP (Brazil); Artel, B.W.H. [EMBRARAD - Empresa Brasileira de Radiacoes Ltda, Av. Cruzada Bandeirante, 269, CEP 06705-140 - Cotia (Brazil); Lugao, A.B. [IPEN/CNEN - Instituto de Pesquisas Energeticas e Nucleares, Av. Professor Lineu Prestes, 2242, CEP 05508-000 - Cidade Universitaria, Sao Paulo, SP (Brazil)], E-mail: ablugao@ipen.br

    2007-12-15

    The aim of this paper is to investigate the rheological properties of polypropylene (PP) modified by ionization radiation (gamma rays) in the presence of two different monomers. The samples were mixed in a twin-screw extruder with ethylene glycol dimethacrylate (EGDMA) or trimethylolpropane trimethacrylate (TMPTMA) with concentration in the range of 0.5-5.0 mmol. After that, they were irradiated with 20 kGy dose of gamma radiation. The structural modification of polypropylene was analyzed in the melt state by measuring melt flow rate (MFR), {eta}* (complex viscosity) and G' (storage modulus) in the angular frequency range of 10{sup -1} to 3 x 10{sup 2} rad s{sup -1}. From the oscillatory rheology data, one could obtain the values of {eta}{sub 0} (zero shear viscosity) that would be related to the molar mass. All results were discussed with respect to the crosslinking and degradation process that occur in the post-reactor treatment to produce controlled rheology polypropylene. The resulting polymeric materials were submitted the cytotoxicity in vitro test by neutral red uptake methodology with NCTC L 929 cell line from American Type Culture Collection bank. All modified PP samples presented no cytotoxicity.

  20. Rheological study of polypropylene irradiated with polyfunctional monomers

    International Nuclear Information System (INIS)

    The aim of this paper is to investigate the rheological properties of polypropylene (PP) modified by ionization radiation (gamma rays) in the presence of two different monomers. The samples were mixed in a twin-screw extruder with ethylene glycol dimethacrylate (EGDMA) or trimethylolpropane trimethacrylate (TMPTMA) with concentration in the range of 0.5-5.0 mmol. After that, they were irradiated with 20 kGy dose of gamma radiation. The structural modification of polypropylene was analyzed in the melt state by measuring melt flow rate (MFR), η* (complex viscosity) and G' (storage modulus) in the angular frequency range of 10-1 to 3 x 102 rad s-1. From the oscillatory rheology data, one could obtain the values of η0 (zero shear viscosity) that would be related to the molar mass. All results were discussed with respect to the crosslinking and degradation process that occur in the post-reactor treatment to produce controlled rheology polypropylene. The resulting polymeric materials were submitted the cytotoxicity in vitro test by neutral red uptake methodology with NCTC L 929 cell line from American Type Culture Collection bank. All modified PP samples presented no cytotoxicity

  1. Contact angle analysis of corona treated polypropylene films

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Alejandra J. Monsiváis-Barrón

    2014-10-01

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

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

    Science.gov (United States)

    Prez Cceres, Irene; Martnez Poyatos, David; Simancas, Jos Fernando; Azor, Antonio

    2014-05-01

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

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

    International Nuclear Information System (INIS)

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

  5. Mainpack 10.0. Software para la gestión de la actividad de mantenimiento en la industria azucarera

    OpenAIRE

    Santiago Estupiñán-Díaz; Irina Vargas-Vargas

    2015-01-01

    El mantenimiento es una actividad de vital importancia en la industria; al aplicarse se logra un mayor alargamiento de la vida útil del equipo, una reducción significativa de los costos en reparación y gastos en repuestos, así como de aquellos gastos que incurren en la mano de obra ligada a la actividad. En el presente trabajo se expone Mainpack 10.0, un sistema para la gestión del mantenimiento y las reparaciones del equi- pamiento en la industria azucarera. Al automatizar el proceso de mant...

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

    OpenAIRE

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

    2012-01-01

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

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

    OpenAIRE

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

    2015-01-01

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

  8. 21 CFR 878.5000 - Nonabsorbable poly(ethylene terephthalate) surgical suture.

    Science.gov (United States)

    2010-04-01

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

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

    DEFF Research Database (Denmark)

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

    1988-01-01

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

  10. Comparison of effects of suture and cyanoacrylate tissue adhesive on bacterial counts in contaminated lacerations.

    OpenAIRE

    Howell, J M; Bresnahan, K A; Stair, T O; Dhindsa, H S; Edwards, B A

    1995-01-01

    We studied the effects of closing lacerations with suture or cyanoacrylate tissue adhesive on staphylococcal counts in inoculated guinea pig lacerations. Wounds closed with adhesive alone had lower counts than wounds containing suture material (P < 0.05). The results of a time-kill study were consistent with a bacteriostatic adhesive effect of the adhesive against Staphylococcus aureus.

  11. Usefulness of Irradiated Polyglactin 910 (Vicryl Rapide) for Skin Suturing during Surgery for Lateral Ray Polydactyly of the Toes in Children

    OpenAIRE

    Hajime Matsumine, MD, PhD; Masaki Takeuchi, MD, PhD

    2013-01-01

    Background: This study describes the use of a bioabsorbable suture for skin suturing during surgery for lateral ray polydactyly followed by favorable postoperative outcome without the need for postoperative suture removal. Methods: A 5-0 Vicryl Rapide suture was used for skin suturing during surgery for lateral ray polydactyly in 9 children (mean age, 12.4 mo). Children were allowed to walk and bathe 2 weeks after surgery when over-the-suture taping therapy was started. Results: In all cases,...

  12. 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.

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

    Scientific Electronic Library Online (English)

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

    2015-06-01

    Full Text Available PURPOSE: To compare the inflammatory response of three different meshes on abdominal hernia repair in an experimental model of incisional hernia. METHODS: Median fascial incision and skin synthesis was performed on 30 Wistar rats. After 21 days, abdominal hernia developed was corrected as follows: [...] 1) No mesh; 2) Polypropylene mesh; and, 3) Ultrapro(r) mesh. After 21 days, the mesh and surrounding tissue were submitted to macroscopic (presence of adhesions, mesh retraction), microscopic analysis to identify and quantify the inflammatory and fibrotic response using a score based on a predefined scale of 0-3 degrees, evaluating infiltration of macrophages, giant cells, neutrophils and lymphocytes. RESULTS: No significant difference was seen among groups in adherences, fibrosis, giant cells, macrophages, neutrophils or lymphocytes (p>0.05). Mesh shrinkage was observed in all groups, but also no difference was observed between polypropylene and Ultrapro mesh (7.09.9 vs. 7.410.1, respectively, p=0.967). Post-operatory complications included fistula, abscess, dehiscence, serohematic collection and reherniation, but with no difference among groups (p=0.363). CONCLUSION: There is no difference between polypropylene (high-density) and Ultrapro(r) (low-density) meshes at 21 days after surgery in extraperitoneal use in rats, comparing inflammatory response, mesh shortening, adhesions or complications.

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

    KAUST Repository

    Yudhanto, Arief

    2016-03-08

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

  15. Mainpack 10.0. Software para la gestión de la actividad de mantenimiento en la industria azucarera

    Directory of Open Access Journals (Sweden)

    Santiago Estupiñán-Díaz

    2015-01-01

    Full Text Available El mantenimiento es una actividad de vital importancia en la industria; al aplicarse se logra un mayor alargamiento de la vida útil del equipo, una reducción significativa de los costos en reparación y gastos en repuestos, así como de aquellos gastos que incurren en la mano de obra ligada a la actividad. En el presente trabajo se expone Mainpack 10.0, un sistema para la gestión del mantenimiento y las reparaciones del equi- pamiento en la industria azucarera. Al automatizar el proceso de mantenimiento, incorporando una herramienta informática como MainPack 10.0 se agilizan y controlan eficientemente todos los aspectos organizativos y financieros de la actividad de mantenimiento. Para el desarrollo de esta aplicación de gestión del mantenimiento asistido por ordenador (GMAO se ana- lizaron una serie de actividades que se realizan duran- te el proceso de mantenimiento, como son: planificación, identificación del equipamiento, incidencias, pasaportes o fichas técnicas del equipo, diagnósticos, etc. El software presenta una interfaz amigable y las funcionalidades incluidas en su diseño facilitan su uso y explotación. En este trabajo se ofrecen datos reales del sistema para demostrar su utilidad y posibilidades.

  16. Lateral intercrural suture in the caucasian nose: Decreased domal divergence angle in endonasal rhinoplasty without delivery

    Directory of Open Access Journals (Sweden)

    Berger, Cezar Augusto Sarraf

    2012-01-01

    Full Text Available Introduction: Several techniques can be performed to improve nasal tip definition such as cartilage resection, tip grafts, or sutures. Objective: To evaluate the outcome of lateral intercrural suture at the lower lateral cartilage by endonasal rhinoplasty with a basic technique without delivery in decreasing the angle of domal divergence and improving the nasal tip definition. Method: This prospective study was performed in 64 patients in which a suture was made on the board head of the lower lateral cartilage in the joint between the dome and lateral crus, using polydioxanone (PDS with sharp, curved needle. Results: In all of the cases, better definition of the nasal tip was achieved by intercrural suturing for at least 6 months postoperatively. Conclusion: Lateral intercrural suture of the lower lateral cartilage provides improved nasal tip definition and can be performed by endonasal rhinoplasty without delivery in the Caucasian nose.

  17. Comparative trial of Dexon (polyglycolic acid), collagen, and silk sutures in ophthalmic surgery.

    Science.gov (United States)

    Chatterjee, S

    1975-12-01

    The tissue reaction, absorption, and handling properties of Dexon synthetic absorbable sutures, which are made from polymerized hydroxyacetic acid, were compared with those of silk and collagen in 51 eye operations, consisting mainly of cataract extractions and squint corrections. There was no significant difference between the sutures as regards degree of tissue reaction. The Dexon sutures were very strong and the knots held well. The sizes used in this series were found to be a little too thick and stiff for use in micro-surgery; smaller sizes would be easier to use and still remain strong enough. The Dexon was reliably absorbed in 5 weeks on average. No serious adverse reactions were seen with any of the sutures. Dexon was as well tolerated as the control sutures but had the advantage over silk of being absorbed and over collagen of containing no foreign protein. PMID:766826

  18. Clinical Results of Meniscal Repair Using Submeniscal Horizontal Sutures

    Directory of Open Access Journals (Sweden)

    Amir Mohammad Navali

    2015-07-01

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

  19. Transcutaneous Serdev Suture For Buttocks Lift

    Directory of Open Access Journals (Sweden)

    Nikolay Serdev

    2012-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Nascimento Luiz Roberto do

    1999-01-01

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

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

    OpenAIRE

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

    2009-01-01

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

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

    Directory of Open Access Journals (Sweden)

    S.T. Jayanth

    2015-12-01

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

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

    Science.gov (United States)

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

    2015-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Ning Liu

    2014-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Srikanth G

    2011-01-01

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

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

    OpenAIRE

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

    2000-01-01

    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 r...

  7. Effect of γ-radiation on trypsin immobilized at a modified polypropylene textile material

    International Nuclear Information System (INIS)

    In studying the proteolytic activity and ESR spectra of γ-irradiated samples of trypsin immobilized at an inoculated copolymer of polypropylene with polyacrylic acid it was established that the carrier of a modified polypropylene increase the radioresistances of trypsin immobilized on it

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

    Science.gov (United States)

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

  9. 78 FR 78748 - 2,5-Furandione, polymer With ethenylbenzene, Reaction Products With polyethylene-polypropylene...

    Science.gov (United States)

    2013-12-27

    ...-polypropylene glycol 2-aminopropyl Me ether; minimum number average molecular weight (in amu), 14,000 (CASRN... absorbing polymer with a number average molecular weight (MW) greater than or equal to 10,000 daltons. 7... polyethylene-polypropylene glycol 2- aminopropyl Me ether; minimum number average molecular weight (in amu),......

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

    OpenAIRE

    Moorman, Valerie J.; Jann, Henry W.

    2009-01-01

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

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

    Science.gov (United States)

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

    2015-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Bhatia, J.

    1981-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Martin Bajus

    2006-03-01

    Full Text Available Low-density polyethylene and polypropylene were thermally decomposed individually in a batch reactor at 450C 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.

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Alireza Saied

    2015-09-01

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

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

    Science.gov (United States)

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

    2011-03-01

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

  19. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-15

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

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

    Science.gov (United States)

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

    2014-01-01

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

  2. Enhanced Zone II Flexor Tendon Repair through a New Half Hitch Loop Suture Configuration

    Science.gov (United States)

    Thomopoulos, Stavros; Gelberman, Richard H.

    2016-01-01

    This study evaluated the impact of a new half hitch loop suture configuration on flexor tendon repair mechanics. Cadaver canine flexor digitorum profundus tendons were repaired with 4- or 8-strands, 4–0 or 3–0 suture, with and without half hitch loops. An additional group underwent repair with half hitch loops but without the terminal knot. Half hitch loops improved the strength of 8-strand repairs by 21% when 4–0, and 33% when 3–0 suture was used, and caused a shift in failure mode from suture pullout to suture breakage. 8-strand repairs with half hitch loops but without a terminal knot produced equivalent mechanical properties to those without half hitch loops but with a terminal knot. 4-strand repairs were limited by the strength of the suture in all groups and, as a result, the presence of half hitch loops did not alter the mechanical properties. Overall, half hitch loops improved repair mechanics, allowing failure strength to reach the full capability of suture strength. Improving the mechanical properties of flexor tendon repair with half hitch loops has the potential to reduce the postoperative risk of gap formation and catastrophic rupture in the early postoperative period. PMID:27101409

  3. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.)

  5. 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.)

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

    Directory of Open Access Journals (Sweden)

    Vogt Peter M

    2009-08-01

    Full Text Available Abstract Background Treatment of ruptured Achilles tendons currently constitutes of conservative early functional treatment or surgical treatment either by open or minimal invasive techniques. We hypothesize that an experimental Achilles tendon suture in an animal model significantly deteriorates Achilles tendon microcirculation immediately following suturing. Methods Fifteen Achilles tendons of eight male Wistar rats (275325 g were included. After preparation of the Achilles tendon with a medial paratendinous approach, Achilles tendon microcirculation was assessed using combined Laser-Doppler and spectrophotometry (Oxygen-to-see regarding: - tendinous capillary blood flow [arbitrary units AU] - tendinous tissue oxygen saturation [%] - tendinous venous filling pressure [rAU] The main body of the Achilles tendon was measured in the center of the suture with 50 Hz. 10 minutes after Achilles tendon suture (6-0 Prolene, a second assessment of microcirculatory parameters was performed. Results Achilles tendon capillary blood flow decreased by 57% following the suture (70 30 AU vs. 31 16 AU; p Conclusion Achilles tendon suture in anaesthetised rats causes an acute loss of capillary perfusion and increases postcapillary venous filling pressures indicating venous stasis. The primary hypothesis of this study was confirmed. In contrast, tendinous tissue oxygen saturation remains unchanged excluding acute intratendinous hypoxia within the first 10 minutes after suture. Further changes of oxygen saturation remain unclear. Furthermore, it remains to be determined to what extent reduced capillary blood flow as well as increased postcapillary stasis might influence tendon healing from a microcirculatory point of view in this animal setting.

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

    CERN Document Server

    Kravets, L I; Apel, P Yu

    2000-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Myrtha Karina

    2007-01-01

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

  10. 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 μm to 10 μm, and in sizes up to 100 mmx125 mm have been developed. (orig.)

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

    Science.gov (United States)

    Pfaff, Reinhard

    1990-10-01

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

  12. Radiation Damage of Polypropylene Fiber Targets in Storage Rings

    CERN Document Server

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

    2004-01-01

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

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

    Science.gov (United States)

    Moshkova, T A

    2008-01-01

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

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

    OpenAIRE

    C.H. Azhari; Wong, S F

    2001-01-01

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

  15. Rheological behaviour of polypropylene blends utilized in foaming process

    Czech Academy of Sciences Publication Activity Database

    Piyamanocha, P.; Sedláček, T.; Polášková, M.; Filip, Petr; Sáha, P.

    Athens : WSEAS, 2010 - (Martin, O.; Zheng, X.), s. 275-278 ISBN 978-960-474-203-5. ISSN 1792-4294. - (Mathematics and Computers in Science Engineering). [WSEAS International Conference on Engineering Mechanics, Structures, Engineering Geology /3./ (EMESEG '10), International Conference on Geography and Geology 2010 (WORLDGEO '10). Corfu (GR), 22.07.2010-24.07.2010] Grant ostatní: GA MPO(CZ) 2A-1TP1/126 Institutional research plan: CEZ:AV0Z20600510 Keywords : polypropylene foam * rheology * strain hardening * foam morphology * pressure dependent viscosity Subject RIV: BK - Fluid Dynamics

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

    OpenAIRE

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2015-11-01

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

  18. 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)

  19. Supermolecular structure changes in polypropylene filled with Au nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Šlouf, Miroslav; Kratochvíl, Jaroslav; Baldrian, Josef; Pavlova, Ewa; Hromádková, Jiřina; Masirek, R.; Piorkowska, E.

    Rio de Janeiro : International Union of Pure and Applied Chemistry , 2006, s. 1-2. [World Polymer Congress Macro 2006 /41./. Rio de Janeiro (BR), 16.07.2006-21.07.2006] R&D Projects: GA ČR GA106/04/1118; GA ČR GA203/04/0688 Grant ostatní: Ministry of Education and Science(PL) 3T08E 059 29 Institutional research plan: CEZ:AV0Z40500505 Keywords : Au nanoparticles * polypropylene * super-molecular structure Subject RIV: CD - Macromolecular Chemistry

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

    OpenAIRE

    G. N. Onyeagoro

    2013-01-01

    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 wt...

  1. Evaluation of tensile strength of surgical synthetic absorbable suture materials: an in vitro study

    OpenAIRE

    Khiste, Sujeet Vinayak; Ranganath, V.; Nichani, Ashish Sham

    2013-01-01

    Purpose The purpose of this study was to evaluate the tensile strength of surgical synthetic absorbable sutures over a period of 14 days under simulated oral conditions. Methods Three suture materials (polyglycolic acid [PGA], polyglactin [PG] 910, and poly (glycolide-co-є-caprolactone) [PGC]) were used in 4-0 and 5-0 gauges. 210 suture samples (35 of each material and gauge) were used. All of the samples were tested preimmersion and 1 hour and 1, 3, 7, 10, and 14 days postimmersion. The tens...

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

    OpenAIRE

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

    2013-01-01

    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...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-15

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

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

    Directory of Open Access Journals (Sweden)

    Li ZR

    2012-03-01

    Full Text Available Zhanrong Li1, Lin Yao1, Jingguo Li2, Wenxin Zhang1, Xianghua Wu1, Yi Liu1, Miaoli Lin1, Wenru Su1, Yongping Li1, Dan Liang11State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, 2School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, People's Republic of ChinaPurpose: Celastrol, a traditional Chinese medicine, is widely used in anti-inflammation and anti-angiogenesis research. However, the poor water solubility of celastrol restricts its further application. This paper aims to study the effect of celastrol nanoparticles (CNPs on corneal neovascularization (CNV and determine the possible mechanism.Methods: To improve the hydrophilicity of celastrol, celastrol-loaded poly(ethylene glycol-block-poly(ε-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

  5. Radiation Modification of Polypropylene Waste for Using as Electrolyte Membranes

    International Nuclear Information System (INIS)

    Graft copolymerization of styrene onto polypropylene (PP) and waste polypropylene (WPP) films has been carried out by means of γ-irradiation. The parameters may affect the grafting yield such as irradiation dose, type of solvent, inhibitor concentration, irradiation atmosphere and monomer concentration were optimized. The grafted films were then treated with chlorosulfonic acid to introduce sulfonic group as a high proton exchange moiety. The obtained membranes were characterized by using fourier transform infrared spectroscopy (FTIR), and studying their swelling behavior, thermal and mechanical properties. The electrical properties of the prepared membranes were evaluated as a function of degree of grafting, hydration number and their ionic conductivity. The results showed that the ionic conductivity of the WPP increases from 6 x 10-10 to 2.8 multiplication sign 10-2 S/ cm and for PP increases from 7x10-10 to 4.1x10-3 S/cm by changing the grafting degree. The chemical, physical and electrical characteristics of the prepared membranes recommend these membranes as potential candidate for proton exchange membrane fuel cell (PEMFC) applications

  6. On engineering of properties of wood-polypropylene composite

    Directory of Open Access Journals (Sweden)

    Điporović Milanka

    2006-01-01

    Full Text Available New materials based on wood have the advantage in the sense that their properties can be engineered so as to correspond to user demands. The properties which can be engineered are those relating both to their utilisation and machining, in particular - the tensile strength, elongation at break, modulus of elasticity and impact resistance. The research at the Faculty of Forestry and "Hipol" Chemical Industry related to the new type of wood-polypropylene composite. The content of wood filler was varied in the range between 40% and 70% mass contents of beech wood flour. After the highest tensile strength at 50% of filler content was determined, the effect of the wood filler origin was also examined at this content value. Therefore, wood flour of beech, poplar, acetylated pine and the waste MDF was used. The influence of the composition of the wood filler (beech combined with MDF, poplar and acetylated pine in comparison with pure polypropylene matrix was also examined, as well as the effect of the type of coupling agent. Hopefully, the results obtained in this study might serve as the initial data for production of easily machined high-strength composites.

  7. Chemical modification of polypropylene induced by high energy carbon ions

    International Nuclear Information System (INIS)

    Polypropylene was irradiated with 12C+ ions of 3.6 and 5.4 MeV energy using 3 MV Pelletron. The spectral changes owing to ion bombardment were investigated by UV-VIS and Fourier-transform infrared (FTIR) spectroscopy. A gradual increase in absorbance was observed around visible and near visible region with increase in fluence of bombarding ions. The difference absorption spectra show formation of chromophoric groups with wavelength maximum near 380 nm at lower fluence, but at high fluence a shift in peak is observed. The chromophoric groups are likely to be the extended conjugated polyene system and the red shift in peak position at high fluence may be attributed to the greater degree of conjugation. The formation of unsaturated linkage is confirmed by the FTIR spectra with observed stretching band around 1650 cm-1 and its intensity was found to increase with increase in ion fluence studied. The gases (in the range 2-80 amu) which were evolved due to interaction of polypropylene with 12C+ ions were measured with Residual Gas Analyzer (RGA). A large number of gaseous components were detected. This shows that polymer chains break into some smaller fragments which concomitantly leads to extended conjugation

  8. 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.

  9. Acoustic properties of polypropylene composites reinforced with stone groundwood

    Directory of Open Access Journals (Sweden)

    Joan Pere López

    2012-11-01

    Full Text Available Currently, acoustic isolation is one of the problems raised with building construction in Spain. The publication of the Basic Document for the protection against noise of the Technical Building Code has increased the demand of comfort for citizens. This has created the need to seek new composite materials that meet the new required acoustical building codes. In this paper we report the results of the newly developed composites that are able to improve the acoustic isolation of airborne noise. These composites were prepared from polypropylene (PP reinforced with mechanical pulp fibers from softwood (Pinus radiata. Mechanical and acoustical properties of the composites from mechanical pulp (MP and polypropylene (PP have been investigated and compared to fiberglass (FG composites. MP composites had lower tensile properties compared with FG composites, although these properties can be improved by incorporation of a coupling agent. The results of acoustical properties of MP composites were reported and compared with the conventional composites based on fiberglass and gypsum plasterboards. Finally, we suggest the application of MP composites as a light-weight building material to reduce acoustic transmitions.

  10. Photodegradation of a polypropylene filled with lanthanide complexes

    Directory of Open Access Journals (Sweden)

    Valérie Massardier

    2015-01-01

    Full Text Available Abstract This research aims at studying the photodegradation of a polypropylene formulation filled with lanthanide complexes. These complexes can be used as tracers for the identification of polymer materials in order to facilitate an high speed automatic sorting of plastic wastes for an economically efficient recycling. By paying attention to the evolution of carbonyl absorption bands in FTIR spectra, it is observed that the addition of lanthanide complexes into our formulation improves UV stability of polypropylene by reducing the extent of photo-degradation. Furthermore, TG analyses show that the traced blends can maintain better thermal properties, after irradiation. A significant increase of the crystallinity degree and a decrease of the melting temperature are more pronounced for the unfilled UV–irradiated PP. This might result from chemi-crystallization that can occur when chain entanglements are broken as a result of chain scissions. From SEM analyses, it is observed that the severity of surface cracks induced by photo degradation is reduced for filled PP. The mechanical tests are in agreement with this result and show a fundamental change in the behavior of the as-exposed blends from a ductile to a brittle material.

  11. 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.)

  12. Preparation and Characterization of Coir, Luffa Reinforced Polypropylene Composites

    Directory of Open Access Journals (Sweden)

    S.Tharaknath

    2014-10-01

    Full Text Available Natural fibres have been used to reinforce materials for over 3,000 years. More recently they have been employed in combination with plastics. Many types of natural fibres have been investigated for use in plastics including coir, luffa, flax, hemp, jute, sisal, and banana. Natural fibres have the advantages that they are renewable resources and have marketing appeal. These agricultural wastes can be used to prepare fibre reinforced polypropylene composites for commercial use. Application of composite materials to structures have presented the need for the engineering analysis this work focuses on the fabrication of polymer matrix composites by using natural fibres like coir, and luffa which are abundant nature in desired shapes by the help of various structures of patterns and calculating its material characteristics (tensile strength, flexural modulus, flexural rigidity, hardness number,% gain of water by conducting tests like tensile test, flexural test, hardness test, water absorption test, impact test, density test, sem analysis and their results are measured on sections of the material and make use of the natural fibre reinforced polypropylene composite material for automotive seat shell manufacturing.

  13. 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.

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

    Science.gov (United States)

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

    2002-02-01

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

  15. Stem cells of the suture mesenchyme in craniofacial bone development, repair and regeneration.

    Science.gov (United States)

    Maruyama, Takamitsu; Jeong, Jaeim; Sheu, Tzong-Jen; Hsu, Wei

    2016-01-01

    The suture mesenchyme serves as a growth centre for calvarial morphogenesis and has been postulated to act as the niche for skeletal stem cells. Aberrant gene regulation causes suture dysmorphogenesis resulting in craniosynostosis, one of the most common craniofacial deformities. Owing to various limitations, especially the lack of suture stem cell isolation, reconstruction of large craniofacial bone defects remains highly challenging. Here we provide the first evidence for an Axin2-expressing stem cell population with long-term self-renewing, clonal expanding and differentiating abilities during calvarial development and homeostastic maintenance. These cells, which reside in the suture midline, contribute directly to injury repair and skeletal regeneration in a cell autonomous fashion. Our findings demonstrate their true identity as skeletal stem cells with innate capacities to replace the damaged skeleton in cell-based therapy, and permit further elucidation of the stem cell-mediated craniofacial skeletogenesis, leading to revealing the complex nature of congenital disease and regenerative medicine. PMID:26830436

  16. 77 FR 8117 - Medical Devices; Cardiovascular Devices; Classification of the Endovascular Suturing System

    Science.gov (United States)

    2012-02-14

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

  17. Complications of suture ligation ablation for ulnar polydactyly: a report of two cases.

    Science.gov (United States)

    Patillo, Dominic; Rayan, Ghazi M

    2011-03-01

    We report two cases resulting in complications following suture ligation treatment for ulnar polydactyly. One case consisted of bilateral, retained gangrene and cellulitis, and a second case consisted of a residual, sensitive skin tag. The case involving gangrene and cellulitis developed after an unsuccessful suture ligation of bilateral pedunculated duplicated digits. The second case developed after suture ligature ablation of a rudimentary digit in the nursery but presented 3 years later with a residual symptomatic nubbin. Both cases were treated by surgical excision of the residual tissue in the operating room. The first case illustrates a morbid complication following unsuccessful ligature while the second case demonstrates the inevitable suboptimal long-term outcome associated with what has traditionally been considered "successful" suture ligation. PMID:22379449

  18. Effects of surface modification of talc on mechanical properties of polypropylene/talc composites

    Science.gov (United States)

    Liu, Keyan; Stadlbauer, Wolfgang; Zitzenbacher, Gernot; Paulik, Christian; Burgstaller, Christoph

    2016-03-01

    Low compatibility of polymer matrix and dispersed filler negatively affects the performance of polymeric composites. In order to improve the adhesion between the components in a compound the polymer matrix or/and the filler particles should be modified with a compatibilizer or/and a coupling agent. An overview of our current research on the effect of the addition of silane treated and untreated talc powders on the mechanical properties of polypropylene/talc composites is presented in this paper. Different silane coupling agents (3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane) were used to improve the adhesion at the surface of talc powders. Maleic anhydride grafted polypropylene was utilized to increase the adhesion between the polypropylene matrix and talc powders. The content of maleic anhydride grafted polypropylene (MA-g-PP) was varied between 1 and 5 wt% in polypropylene/talc composites. The surface modification of talc powders has a significant effect on the interfacial structure and the mechanical properties such as tensile strength and impact strength of polypropylene/talc composites. The experiments show that polypropylene grafted with maleic anhydride together with silane surface treatment exhibits the highest potential for improvements in this field.

  19. 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.

  20. TENSILE STRENGTH CHARACTERISTICS OF POLYPROPYLENE COMPOSITES REINFORCED WITH STONE GROUNDWOOD FIBERS FROM SOFTWOOD

    Directory of Open Access Journals (Sweden)

    Joan P. López,

    2012-06-01

    Full Text Available The behavior of stone groundwood / polypropylene injection-molded composites was evaluated with and without coupling agent. Stone groundwood (SGW is a fibrous material commonly prepared in a high yield process and mainly used for papermaking applications. In this work, the use of SGW fibers was explored as a reinforcing element of polypropylene (PP composites. The surface charge density of the composite components was evaluated, as well as the fiber’s length and diameter inside the composite material. Two mixing extrusion processes were evaluated, and the use of a kinetic mixer, instead of an internal mixer, resulted in longer mean fiber lengths of the reinforcing fibers. On the other hand, the accessibility of surface hydroxyl groups of stone groundwood fibers was improved by treating the fibers with 5% of sodium hydroxide, resulting in a noticeable increase of the tensile strength of the composites, for a similar percentage of coupling agent. A new parameter called Fiber Tensile Strength Factor is defined and used as a baseline for the comparison of the properties of the different composite materials. Finally the competitiveness of stone groundwood / polypropylene / polypropylene-co-maleic anhydride system, which compared favorably to sized glass-fiber / polypropylene GF/PP and glass-fiber / polypropylene / polypropylene-co-maleic anhydride composite formulations, was quantified by means of the fiber tensile strength factor.

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

    International Nuclear Information System (INIS)

    The paper describes the effect of wollastonite and talc on the scratch deformation behavior of low and high crystallinity polypropylenes under identical test conditions. The vertical resolution of atomic force microscopy and lateral resolution of scanning electron microscopy is utilized to examine the characteristics of scratch damage. Contrary to the expectations that high crystallinity and stiffness of polypropylene composites should increase resistance to scratch deformation, the susceptibility to mechanical deformation depends on bonding of mineral particles to the polymer matrix. Scratch deformed regions in neat polypropylenes were free of voids and grooves, while reinforced-polypropylenes exhibited voids and debonding/detachment of filler particles. The severity of plastic deformation in reinforced polypropylenes is a function of debonding/detachment of mineral particles, which is comparatively more for talc-reinforced polypropylenes than wollastonite-reinforced polypropylenes because of the layered structure of talc that encourages delamination. Usage of coating and coupling agents improved the resistance to scratch deformation by promoting adhesion and bonding between the reinforcement and matrix

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

    OpenAIRE

    Lippert, Hans; Jünger, Michael; Heidecke, Claus-Dieter; Guggenbichler, Josef Peter; Assadian, Ojan; Kramer, Axel; Schauer, Frieder

    2006-01-01

    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...

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

    Directory of Open Access Journals (Sweden)

    Manash Ranjan Sahoo

    2014-01-01

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

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

    OpenAIRE

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

    2011-01-01

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

  5. Sutural loosening and skeletal flexibility during growth: determination of drop-like shapes in sea urchins.

    OpenAIRE

    Johnson, Amy S.; Ellers, Olaf; Lemire, Jim; Minor, Melissa; Leddy, Holly A

    2002-01-01

    The shape of sea urchins may be determined mechanically by patterns of force analogous to those that determine the shape of a water droplet. This mechanical analogy implies skeletal flexibility at the time of growth. Although comprised of many rigid calcite plates, sutural collagenous ligaments could confer such flexibility if the sutures between plates loosened and acted as joints at the time of growth. We present experimental evidence of such flexibility associated with weight gain and grow...

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

    OpenAIRE

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

    2003-01-01

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

  7. Comparison of cyanoacrylate and silk sutures on healing of oral wounds--an animal model study.

    OpenAIRE

    Kulkarni Sudhindra; Chava Vijay

    2003-01-01

    Cyanoacrylates are tissue adhesives used for closure of surgical wounds. N-butyl cyanoacrylate is a biocompatible tissue adhesive used for closure of surgical wounds. In the present study evaluation and comparison the healing of oral wounds was done when closed with N-butyl cyanoacrylate and silk sutures in a rabbit model. It was found clinically that the sites treated with cyanoacrylate had less inflammation and healed better at 7 days as compared to the sutured sites. At 7 days the histolog...

  8. Comparison of octyl-2-cyanoacrylate and conventional sutures in facial skin closure

    OpenAIRE

    Shivamurthy, D. M.; Singh, Sourav; Reddy, Sasidhar

    2010-01-01

    Introduction: Closure of wounds to achieve an esthetically pleasing result has always been a challenge. Since time immemorial, surgeons have strived to produce “invisible scars”. This, however, has always been elusive. The introduction of tissue adhesives heralded the era of suture free closures which led to better results. Aims and Objectives: The aim of this study is to compare the efficacy of octyl- 2-cyanoacrylate with that of the conventional sutures, in facial skin closure. Results and ...

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

    OpenAIRE

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

    2013-01-01

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

  10. Galeal Tack-Up Sutures to Prevent Subgaleal Cerebrospinal Fluid Collection

    OpenAIRE

    Choi, Won Ho; Moon, Chang Taek; Koh, Young-Cho; Chun, Young Il; Cho, Joon; Song, Sang Woo

    2013-01-01

    Objective Postoperative subgaleal cerebrospinal fluid (CSF) collection is considered as one of the common minor surgical complication which can lead to prolonged hospitalization. We introduce "galeal tack-up suture" to prevent postoperative subgaleal CSF collection. Methods Galeal tack-up suture consists of various surgical techniques which aim to fix galea to cranium in order to prevent CSF pooling in subgaleal space. A total of 87 patients who underwent craniotomy were divided into two grou...

  11. Closure of round cutaneous defects progressively with the purse string suture technique

    OpenAIRE

    KÜÇÜKDURMAZ, Fatih; Agir, Ismail; Gümüstas, Seyitali; Kivilcim, Hakan; Tetik, Cihangir

    2015-01-01

    Introduction There are many closure techniques available to cutaneous surgeons. One of them is the purse-string suture which is used to provide complete or partial closure of round skin defects. In our animal study; we closed skin defects with using subcuticular purse string suture technique by progressively cinching wound and we aim to more rapidly healing according to secondary healing. Methods After anaesthetize, we created a 4 cm diameter circular full thickness skin defect on dorsal area...

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

    Science.gov (United States)

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

    2012-03-01

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

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

    International Nuclear Information System (INIS)

    Highlights: • We designed and prepared β nucleated thermoplastic vulcanizates. • We adopted the β nucleated TPV to toughen polypropylene. • Greatly improved toughness of iPP, limited loss in strength and rigidity was achieved. • A toughening mechanism was proposed. - Abstract: A series of dynamically vulcanized isotactic polypropylene (PP)/ethylene–propylene–diene rubber thermoplastic vulcanizates (TPVs) containing different content of β-nucleating agent (β-NA) were prepared and introduced into isotactic PP matrix as a toughening agent. The effect of β-nucleated TPVs (β-TPVs) on the toughness and other properties of PP were studied. Differential scanning calorimetry and wide-angle X-ray diffraction results indicated that the β-crystallinity and the relative content of β-phase in β-TPVs samples and the toughened blends increased with the content of β-NA increasing. The notched impact strength of PP toughened by β-TPVs, with limited loss in the tensile strength and rigidity, showed an almost linear increase with increasing β-NA content. Especially when the content of β-NA was 0.5 wt%, the impact strength of the toughened blends was ten times more than that of pure PP. The toughening mechanism based on classical rubber toughening mechanisms was discussed and a synergic toughening mechanism was proposed

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

    Directory of Open Access Journals (Sweden)

    Murali Mothilal

    2013-07-01

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

  15. A clinical study on the influence of suturing material on oral wound healing

    Directory of Open Access Journals (Sweden)

    Gazivoda Dragan

    2015-01-01

    Full Text Available Background/Aim. Suture materials play an important role in healing, enabling reconstruction and reassembly of tissue separated by the surgical procedure or trauma, and at the same time facilitating and promoting healing and hemostasis. Suture materials are used daily in oral surgery, and are considered to be substances most commonly implanted in human body. The aim of this clinical study was to examine the speed of wound healing and complications incidence, after the use of three different absorbable synthetic suture materials in oral surgery (catgut, Dexon and Vicryl rapide, and to ascertain which one is the most suitable for oral surgery. Methods. The study was conducted on 96 patients undergoing root resection or surgical extraction of third molars. Each of the suture materials (catgut, Dexon and Vicryl rapide was used for 8 root resections and 8 surgical third molar extractions in the maxilla, as well as in the mandible (a total of 32 surgical interventions for each suture material. Results. The faster wound healing was obtained with Vicryl rapide compared to other two suturing material tested. There was no significant difference regarding the presence of local reaction in all the three groups of patients on the 21st postoperative day. Conclusion. The results of our clinical study point out that Vycrilrapid contributes more than catgut or Dexon to faster healing of human wounds, with fewer incidences of wound dehiscence and milder local reactions.

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

    Directory of Open Access Journals (Sweden)

    Sood Archana

    2003-01-01

    Full Text Available Purpose: The study aimed to compute and compare the keratometric astigmatism induced by wound closure with continuous and interrupted sutures in conventional extracapsular cataract extraction with intraocular lens implantation at a single centre in eastern Nepal. Methods: Sixty eyes of 60 patients were included in the study. All patients received conventional extracapsular cataract extraction and single piece modified C-loop posterior chamber intraocular lens. Thirty eyes were sutured with continuous (Group 1 and 30 eyes with interrupted sutures (Group 2. The results were analysed by the unpaired student?s t-test. Results: At the end of 6 weeks, Group 1 patients had significantly higher astigmatism (3.53 2.19D compared to Group 2 patients (1.7 1.35. A majority of patients in both groups had with-the-rule astigmatism throughout the postoperative period. Conclusion: Interrupted sutures cause less astigmatism than continuous suture. The factors responsible for high astigmatism in continuous sutures call for further analysis.

  17. Cranial Suture Closure in Domestic Dog Breeds and Its Relationships to Skull Morphology.

    Science.gov (United States)

    Geiger, Madeleine; Haussman, Sinah

    2016-04-01

    Bulldog-type brachycephalic domestic dog breeds are characterized by a relatively short and broad skull with a dorsally rotated rostrum (airorhynchy). Not much is known about the association between a bulldog-type skull conformation and peculiar patterns of suture and synchondrosis closure in domestic dogs. In this study, we aim to explore breed-specific patterns of cranial suture and synchondrosis closure in relation to the prebasial angle (proxy for airorhynchy and thus bulldog-type skull conformation) in domestic dogs. For this purpose, we coded closure of 18 sutures and synchondroses in 26 wolves, that is, the wild ancestor of all domestic dogs, and 134 domestic dogs comprising 11 breeds. Comparisons of the relative amount of closing and closed sutures and synchondroses (closure scores) in adult individuals showed that bulldog-type breeds have significantly higher closure scores than non-bulldog-type breeds and that domestic dogs have significantly higher closure scores than the wolf. We further found that the prebasial angle is significantly positively correlated with the amount of closure of the basispheno-presphenoid synchondrosis and sutures of the nose (premaxillo-nasal and maxillo-nasal) and the palate (premaxillo-maxillary and interpalatine). Our results show that there is a correlation between patterns of suture and synchondrosis closure and skull shape in domestic dogs, although the causal relationships remain elusive. Anat Rec, 299:412-420, 2016. © 2016 Wiley Periodicals, Inc. PMID:26995336

  18. Effect of the suture technique on postoperative pain, swelling and trismus after removal of lower third molars: A randomized clinical trial

    OpenAIRE

    Gay Escoda, Cosme; Gómez Santos, Laia; Sánchez Torres, Alba; Herráez Vilas, José María

    2015-01-01

    Background To evaluate the intensity of pain, swelling and trismus after the removal of impacted lower third molars comparing two different suture techniques of the triangular flap: the complete suture of the distal incision and relieving incision and the partial suture with only one suture knot for closure of the corner of the flap and the closure of the distal incision, without suturing the relieving incision. Material and Methods A prospective, randomized, crossover clinical trial was cond...

  19. Efficacy of Single-Suture Incision Closures in Tagged Juvenile Chinook Salmon Exposed to Simulated Turbine Passage

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-01

    Reductions in the size of acoustic transmitters implanted in migrating juvenile salmonids have resulted in the use of a shorter incision-one that may warrant only a single suture for closure. However, it is not known whether a single suture will sufficiently hold the incision closed when fish are decompressed and when outward pressure is placed on the surgical site during turbine passage through hydroelectric dams. The objective of this study was to evaluate the effectiveness of single-suture incision closures on five response variables in juvenile Chinook salmon Oncorhynchus tshawytscha that were subjected to simulated turbine passage. An acoustic transmitter (0.43 g in air) and a passive integrated transponder tag (0.10 g in air) were implanted in each fish; the 6-mm incisions were closed with either one suture or two sutures. After exposure to simulated turbine passage, none of the fish exhibited expulsion of transmitters. In addition, the percentage of fish with suture tearing, incision tearing, or mortal injury did not differ between treatments. Expulsion of viscera through the incision was higher among fish that received one suture (12%) than among fish that received two sutures (1%). The higher incidence of visceral expulsion through single-suture incisions warrants concern. Consequently, for cases in which tagged juvenile salmonidsmay be exposed to turbine passage, we do not recommend the use of one suture to close 6-mm incisions associated with acoustic transmitter implantation.

  20. Fusion Patterns in the Skulls of Modern Archosaurs Reveal That Sutures Are Ambiguous Maturity Indicators for the Dinosauria.

    Science.gov (United States)

    Bailleul, Alida M; Scannella, John B; Horner, John R; Evans, David C

    2016-01-01

    The sutures of the skulls of vertebrates are generally open early in life and slowly close as maturity is attained. The assumption that all vertebrates follow this pattern of progressive sutural closure has been used to assess maturity in the fossil remains of non-avian dinosaurs. Here, we test this assumption in two members of the Extant Phylogenetic Bracket of the Dinosauria, the emu, Dromaius novaehollandiae and the American alligator, Alligator mississippiensis, by investigating the sequence and timing of sutural fusion in their skulls. As expected, almost all the sutures in the emu skull progressively close (i.e., they get narrower) and then obliterate during ontogeny. However, in the American alligator, only two sutures out of 36 obliterate completely and they do so during embryonic development. Surprisingly, as maturity progresses, many sutures of alligators become wider in large individuals compared to younger, smaller individuals. Histological and histomorphometric analyses on two sutures and one synchondrosis in an ontogenetic series of American alligator confirmed our morphological observations. This pattern of sutural widening might reflect feeding biomechanics and dietary changes through ontogeny. Our findings show that progressive sutural closure is not always observed in extant archosaurs, and therefore suggest that cranial sutural fusion is an ambiguous proxy for assessing maturity in non-avian dinosaurs. PMID:26862766

  1. Identification of pressure-sensitive adhesive polypropylene tape.

    Science.gov (United States)

    Sakayanagi, Masataka; Konda, Yaeko; Watanabe, Kunio; Harigaya, Yoshihiro

    2003-01-01

    Identification of colorless, transparent, pressure-sensitive adhesive polypropylene tape (PP tape) was performed using infrared absorption spectrometry (IR) and pyrolysis gas chromatography mass spectrometry (Py-GC/MS) to determine the pressure-sensitive adhesive. Twenty different products of colorless, transparent PP tapes were examined in this study, and the results of analysis of IR spectra and Py-GC/MS were classified into twelve groups. In addition, the tapes were classified into 14 groups on the basis of IR measurement of release agent present in the backside. The results indicate that colorless, transparent PP tapes can be distinguished in terms of manufacturer, thereby demonstrating that this method of identifying colorless, transparent PP tape is effective. Moreover, the method was applied to the analysis of an actual forensic sample. PMID:12570201

  2. Foaming Behaviour, Structure, and Properties of Polypropylene Nanocomposites Foams

    Directory of Open Access Journals (Sweden)

    M. Antunes

    2010-01-01

    Full Text Available This work presents the preparation and characterization of compression-moulded montmorillonite and carbon nanofibre-polypropylene foams. The influence of these nanofillers on the foaming behaviour was analyzed in terms of the foaming parameters and final cellular structure and morphology of the foams. Both nanofillers induced the formation of a more isometric-like cellular structure in the foams, mainly observed for the MMT-filled nanocomposite foams. Alongside their crystalline characteristics, the nanocomposite foams were also characterized and compared with the unfilled ones regarding their dynamic-mechanical thermal behaviour. The nanocomposite foams showed higher specific storage moduli due to the reinforcement effect of the nanofillers and higher cell density isometric cellular structure. Particularly, the carbon nanofibre foams showed an increasingly higher electrical conductivity with increasing the amount of nanofibres, thus showing promising results as to produce electrically improved lightweight materials for applications such as electrostatic painting.

  3. Effects of the Biodegradation on Biodegradable Polymer Blends and Polypropylene

    Science.gov (United States)

    Pereira, R. C. T.; Franchetti, S. M. M.; Agnelli, J. A. M.; Mattoso, L. H. C.

    2008-08-01

    The large use of plastics in the world generates a large amount of waste which persists around 200 years in the environment. To minimize this effect is important to search some new polymer materials: the blends of biodegradable polymers with synthetic polymers. It is a large area that needs an intensive research to investigate the blends properties and its behavior face to the different treatments to aim at the biodegradation. The blends used in this work are: some biodegradable polymers such as: poly(hydroxybutyrate) (PHB) and poly(ɛ-polycaprolactone) (PCL) with a synthetic polymer, polypropylene (PP), in lower concentration. These blends were prepared using an internal mixer (Torque Rheometer), and pressed. These films were submitted to fungus biotreatment. The films analyses will be carried out by Fourier Transform Infrared (FTIR), UV-Vis absorption (UV-Vis), Scanning Electronic Microscopy (SEM), DSC and TGA.

  4. Processing-property relationships of polypropylene/ciprofloxacin fibers

    Science.gov (United States)

    Botta, L.; Scaffaro, R.

    2015-12-01

    In this work we prepared polypropylene (PP) fibers incorporating an antibiotic, i.e. ciprofloxacin (CFX), by melt spinning. In particular, PP has been compounded with CFX at different concentrations by using a counter-rotating twin screw compounder. The PP/CFX fibers have been spun by using a capillary rheometer operating under a constant extrusion speed. The effect of "online" hot drawing during the melt spinning or of an "offline" cold drawing on the properties of PP/CFX fibers were evaluated. In particular, the influence of the drawing conditions on the mechanical properties and the release kinetics were studied. Moreover, the rheological behavior in non-isothermal elongation flow has been assessed.

  5. Thermal degradation and viscoelasticity of polypropylene-clay nanocomposites

    CERN Document Server

    Drozdov, A D; Drozdov, D A; Gupta, R K

    2003-01-01

    Results of torsional oscillation tests are reported that were performed at the temperature T=230C on melts of a hybrid nanocomposite consisting of isotactic polypropylene reinforced with 5 wt.% of montmorillonite clay. Prior to mechanical testing, specimens were annealed at temperatures ranging from 250 to 310C for various amounts of time (from 15 to 420 min). Thermal treatment induced degradation of the matrix and a pronounced decrease in its molecular weight. An integro-differential equation is derived for the evolution of molecular weight based on the fragmentation-aggregation concept. This relation involves two adjustable parameters that are found by fitting observations. With reference to the theory of transient networks, constitutive equations are developed for the viscoelastic response of nanocomposite melts. The stress-strain relations are characterized by three material constants (the shear modulus, the average energy for rearrangement of strands and the standard deviation of activation energies) tha...

  6. Biocomposites from co-polypropylene and distillers' grains

    Science.gov (United States)

    Zarrinbakhsh, Nima; Mohanty, Amar K.; Misra, Manjusri

    2015-05-01

    In the present work, we have explored the polymeric composites of distillers' grains with co-polypropylene (co-PP). The effect of maleated-PP compatibilizer on mechanical, thermomechanical and physical properties was evaluated. The composite materials were produced by melt extrusion in a micro-compounder followed by injection molding in a micro-injection machine. The composites were characterized for their tensile, flexural and impact properties. Also, melt flow index and heat deflection temperature were measured. The results showed more than 30 % improvement in modulus when comparing the compatibilized biocomposite with neat co-PP. Also, the strength of the compatibilized biocomposite measured in tensile and flexural tests was comparable to or even better than that of the neat matrix. On the other hand, the reduced flexibility and toughness as a result of compatibilization were in an acceptable range. The biocomposites showed more rigidity at elevated temperatures. The produced distillers' grain biocomposites showed promises for industrial applications.

  7. [Treatment of postoperative abdominal hernias with polypropylene endoprosthesis].

    Science.gov (United States)

    Chakhvadze, B Iu; Nakashidze, D Kh

    2009-06-01

    The results of the surgical treatment of 82 patients with postoperative abdominal hernias were analysed. All of the patients underwent surgery with polypropylene endoprosthesis. The choice of a hernioplasty method depended on relative volume of postoperative hernia. Middle-sized hernias were indications for reconstructive surgery (complete adaptation of muscular and aponeurotic layers was maintained). The large and gigantic hernias were indications for correcting surgery (specified diastasis of muscular and aponeurotic layers was maintained). In case of lacking of peritoneum (30 patients) greater omentum was used for isolation of the net from intestinal loops. It is concluded that greater omentum provides good extraperitonisation of transplant from intestinal loop and prevents complications due to contact of net with abdominal organs. Postoperative complications mainly were local and seen in 29% cases. There were no lethal outcomes. PMID:19578204

  8. Effect of polybutenes on mechanical and physical properties of polypropylene

    International Nuclear Information System (INIS)

    This study investigated the effect of polybutene (PIB) of molecular weights ranging from 480 the 1.600 g/mol in polypropylene homopolymer. Compositions with 0, 3, 5 and 7% of PIB were prepared in internal mixer and compression moulded. The properties evaluated were: tensile strength, scanning electron microscopy (SEM), FTIR, X-ray diffraction (XRD) and melt flow index (IF). The results of mechanical tests showed that the presence of the plasticizer reduced the tensile strength, elastic modulus and hardness. The analysis of XRD showed a drop in the degree of crystallinity of PP/PIB blends. The micrographs obtained by SEM did not reveal the occurrence of the phase separation. The IF analysis confirm the effect of PIB as internal lubricant's, by increasing the rate of flow. (author)

  9. Use of Cellulose-Containing Fillers in Composites with Polypropylene

    Directory of Open Access Journals (Sweden)

    Marina TAVROGINSKAYA

    2011-07-01

    Full Text Available The composites, containing recycled polypropylene and fillers, obtained from different lignocellulosics by the thermocatalytic destruction method, were investigated. Birch sawdust, newsprint wastes, cotton residues and wood bleached sulphate pulp were used as raw materials for obtaining fillers. The indices of mechanical properties (tensile strength, modulus of elasticity, deformation at break, shear modulus, toughness, twisting moment of the composites' samples were determined. It has been found that the obtained composites have relatively good mechanical properties. Better results were obtained, using fillers from sawdust and wood pulp. After treating the fillers with rapeseed oil, their water vapour sorption and water retention value (WRV decreased. In this case, the strength of the composites was higher.http://dx.doi.org/10.5755/j01.ms.17.2.484

  10. Unipol PP: a gas-phase route to polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Sawin, S.P.; Baas, C.J.

    1985-05-27

    This article describes the design and operation of Unipol PP, a gasphase, fluid-bed route that couples Union Carbide's Unipol technology for making polyethylene with Shell Chemical Company's superhigh-activity catalyst. Unipol features up to 10-15% lower investment and operating costs than technologies currently being licensed. The technique can produce a complete line of homopolymers, random copolymers and impact copolymers. In addition, because of its broad operating range, many new and improved products can be made. These include: controlled-rheology resins; ultrahigh melt-flow grades; random copolymers and terpolymers having improved clarity and processability; impact copolymers with precisely tailored impact/stiffness characteristics; and thermoplastic polyolefins. Unipol PP technology is one of the safest and cleanest for polypropylene manufacture.

  11. Surface treated polypropylene (PP) fibres for reinforced concrete

    Energy Technology Data Exchange (ETDEWEB)

    López-Buendía, Angel M., E-mail: buendia@uv.es [AIDICO Technological Institute of Construction, Benjamin Franklin 17, 46380 Paterna, Valencia (Spain); Romero-Sánchez, María Dolores [AIDICO Technological Institute of Construction, Marble Technical Unit, Camí de Castella 4, 03660 Novelda. Alicante (Spain); Climent, Verónica [Lafarge Cementos, Polígono Sepes, Isaac Newton s/n, 46500 Sagunto, Valencia (Spain); Guillem, Celia [AIDICO Technological Institute of Construction, Marble Technical Unit, Camí de Castella 4, 03660 Novelda. Alicante (Spain)

    2013-12-15

    Surface treatments on a polypropylene (PP) fibre have contributed to the improvement of fibre/concrete adhesion in fibre-reinforced concrete. The treatments to the PP fibre were characterized by contact angle measurements, ATR-IR and XPS to analyse chemical alterations. The surface topography and fibre/concrete interaction were analysed by several microscopic techniques, namely optical petrographic, and scanning electron microscopy. Treatment modified the surface chemistry and topography of the fibre by introducing sodium moieties and created additional fibre surface roughness. Modifications in the fibre surface led to an increase in the adhesion properties between the treated fibres and concrete and an improvement in the mechanical properties of the fibre-reinforced concrete composite as compared to the concrete containing untreated PP fibres. Compatibility with the concrete and increased roughness and mineral surface was also improved by nucleated portlandite and ettringite mineral association anchored on the alkaline PP fibre surface, which is induced during treatment.

  12. Electrical properties of foamed polypropylene/carbon black composites

    Science.gov (United States)

    Iliev, M.; Kotzev, G.; Vulchev, V.

    2016-02-01

    Polypropylene composites containing carbon black fillers were produced by vibration assisted extrusion process. Solid (unfoamed) composite samples were molded by conventional injection molding method, while structural foams were molded by a low pressure process. The foamed samples were evidenced to have a solid skin-foamed core structure which main parameters were found to depend on the quantity of material injected in the mold. The average bubbles' sizes and their distribution were investigated by scanning electron microscopy. It is established that the conductivity of the foamed samples gradually decreases when reducing the sample density. Nevertheless, the conductivity is found to be lower than the conductivity of the unfoamed samples both being of the same order. The flexural properties of the composites were studied and the results were discussed in the context of the structure parameters of the foamed samples.

  13. Preparation of polypropylene thermoplastic container via thermoforming process

    Science.gov (United States)

    Ruqiyah Nik Hassan, Nik; Amira Mohd Ghazali, Farah; Aziz Jaafar, Abdul; Mazni Ismail, Noor

    2016-02-01

    In this study, plastic containers made of polypropylene (PP) sheets were fabricated via vacuum thermoforming. Thermoforming is a process used in fabricating plastic parts by changing flat thermoplastic sheet to three dimensional shapes. In preparing these thermoplastic containers, the design and fabrication of mould were first done by using Catia V5 software and CNC milling machine, respectively. The thermoforming process was then performed at various temperatures ranging from 160°C until 200°C on the PP sheet to form the container. From the experiment, it can be suggested that the outcomes of final thermoplastic containers are significantly depends on temperature control during thermoforming process and also the vent holes design of the mould.

  14. Space Charge and Electrical Conduction Properties of Polypropylene Copolymer Films

    Science.gov (United States)

    Nakane, Emi; Kaneko, Kazue; Mori, Tatsuo; Mizutani, Teruyoshi; Takino, Hiroshi; Ishioka, Mitsugu

    We investigated the space charge and charging current characteristics in polypropylene copolymer films polymerized with metallocene and Ziegler-Natta catalysts, respectively. Positive and negative homo space charges were observed and their amounts showed maxima at 40 °C. Charge carriers injected from the semiconducting (SC) electrode were dominant at 60 °C. The copolymerization of ethylene enhanced the apparent carrier mobility and the charging current. Evaporated Al electrode showed much less carrier injection than Al plate or SC electrode (mechanically-contacted electrode). Carrier injection from SC electrode was dominant than that from Al plate. These suggest that the space charge formation depends on not only electrode materials but also contact conditions.

  15. Characterization of Fibers Produced from Blends of Polybutylene and Polypropylene

    Directory of Open Access Journals (Sweden)

    Robert L. Shambaugh, Ph.D

    2007-11-01

    Full Text Available Blends of polybutylene (PB-1 and polypropylene were used to produce fibers at spinning speeds of 800-2100 m/min. Concentrations ranged from 0% PP to 100% PP. The stress-strain behavior of the resultant fibers was examined, and the fibers were analyzed for crystallinity via DSC (differential scanning calorimetry. Fibers produced from blends of PB-1/PP show mechanical properties that are in between the properties of the pure polymers. The tensile strength of 50% PB-1 fibers is comparable to the tensile strength of pure PP fibers. Fibers produced from blend compositions of 25 and 75% have higher tensile strengths than pure PP fibers, although these blend compositions have lower tensile strengths than pure PB fibers.

  16. Electret behaviour of Polypropylene/KNO3 composite films

    Science.gov (United States)

    Mancheva, R. D.; Kiradzhiyska, D. D.; Viraneva, A. P.; Yovcheva, T. A.; Galikhanov, M. F.

    2016-03-01

    Polypropylene (PP) is commonly used as a coating of medical implants because of good mechanical and electrical properties. In the present paper the influence of two factors (time storage and temperature storage) on the surface potential decay of PP composite films was investigated. PP composite films with different weight concentrations of the KNO3 particles - 0 wt.%, 2 wt.% and 4 wt.% were investigated. The samples were charged in a positive or in a negative corona by means of a corona triode system and the time dependences of the surface potential were studied for 120 days. The effect of temperature storage on the surface potential was also investigated. The results obtained show a significant change in the electrets behavior of the composite films after the inclusion of KNO3 particles with different concentration into the PP matrix.

  17. Aqueous Processes for Dyeing Generic, Unmodified Polypropylene Fiber

    Directory of Open Access Journals (Sweden)

    Murari L. Gupta

    2010-06-01

    Full Text Available Acid leuco vat dyeings of polypropylene (PP fabrics in combinations of a trichromatic series of colorants (red, yellow and blue plus an orange were performed in order to determine the compatibility of the component colorants in the developed single stage, batch exhaust dyeing process reported earlier. Cross-section micrographs of dyed fibers revealed the absence of "ring-dyeing". Tensile tests and X-ray crystallinity results confirmed that the developed dyeing process did not significantly alter the tensile strength and modulus of the dyed PP textiles. PP fabrics dyed with simulated, continuous acid vat dyeing processes (pad-steam and pad-dry heat demonstrated good color yields and levelness with adequate fastness to crocking, washing and dry cleaning.

  18. Raman Spectra and Mechanical Properties of Graphene/Polypropylene Nanocomposites

    Directory of Open Access Journals (Sweden)

    Siti R. Ahmad

    2015-02-01

    Full Text Available Graphene/Polypropylene nanocomposites were prepared at different filler loading and different average surface diameter 5, 15 and 25?m of graphene nanoplatelets by using Haake Minilab mixer at 180oC and rotor speed 50rpm. Besides, Haake MiniJet is used to obtain dumbbell shape specimen. The effect of filler loading and average surface area of filler in PP/GnP composites on Raman spectrum and tensile properties were studied. Raman spectrum of graphene particles indicate three major spectrums such as D, G and 2D band. In addition, PP/GnP composites shows the Raman band shift quite strong by increasing GnP loading. In general, increased of graphene nanoplatelets loading have increased the value of modulus of elasticity, whereas tensile strength, elongation at break of composites reduced

  19. Editor's Choice - A Randomized Controlled Trial of the Fascia Suture Technique Compared with a Suture-mediated Closure Device for Femoral Arterial Closure after Endovascular Aortic Repair

    DEFF Research Database (Denmark)

    Larzon, T; Roos, H; Gruber, G; Henrikson, O; Magnuson, A; Falkenberg, M; Lönn, L; Norgren, L

    2015-01-01

    OBJECTIVES: The aim was to investigate whether the fascia suture technique (FST) can reduce access closure time and procedural costs compared with the Prostar technique (Prostar) in patients undergoing endovascular aortic repair and to evaluate the short- and mid-term outcomes of both techniques...

  20. Deep suture zone in the North Barents Basin

    Science.gov (United States)

    Butsenko, Viktor; Kireev, Artem; Piskarev, Alexey; Savin, Vasily; Smirnov, Oleg

    2015-04-01

    Study of sedimentary basin evolution is a part of research for the forecast of oil and gas capacity of the North Barents shelf. Maps of potential fields anomalies are compiled on the basis of the latest geophysical databases, structural maps of the seismic horizons are analyzed, the location of sources of potential fields anomalies are calculated, 3D density and magnetic models of Earth's crust are constructed. Six seismic complexes are allocated in sedimentary cover structure: Devonian - Lower Carboniferous, Upper Carboniferous - Lower Permian, Mid Permian - Lower Triassic, Triassic - Lower Jurassic, Upper Jurassic - Lower Cretaceous, Lower Cretaceous - Quaternary. The research of lateral changes of allocated layers thickness gives an idea of sedimentation in the region on various time intervals. The structural and tectonic scheme of the region is made after analysis of new geologic-geophysical materials. Contact zones of heterogeneous blocks of the crystalline basement are marked, disjunctive dislocations in a sedimentary cover and the upper crust, and also zones of increase of sediments thickness in various seismic complexes are designated. The deep suture zone delimiting Mesozoic and Paleozoic sedimentary basins has the most important geological value among disjunctive zones of the region. This zone stretches along the Admiralty Arch in East part of the North Barents shelf and is marked by negative magnetic anomaly 30-50 km wide. In view of special tectonic value of the suture zone marked by this anomaly we have calculated the 3D magnetic crust model. The sedimentary layers of a model section is based on seismic data. As a result of modeling the studied anomaly of a magnetic field can be approximated by the block of basement rocks of the lowered magnetization (1.2 A/m). The surface of this block is located in a zone of anomaly at a depth of 12-14 km. The asymmetry of anomaly is accounted by an inclination to East of the borders of the block with low magnetization. Calculated basement magnetization is 1.9 A/m to the West from an anomaly zone that is a characteristic for many igneous and metamorphic rocks of the diorite composition. Magnetization of the basement formations sharply increases to 3.6 A/m to the East. Similar values of magnetization are characterized basalts and dolerites, and also many metamorphic rocks of the basic and ultrabasic composition. Thus, the simulated magnetic field anomaly not only corresponds to limits of the heterochronous sedimentary basins, but also shows the border between two heterogeneous basement blocks. "Bright spot" anomalies are marked out on seismic sections. Bright spots are mainly located near the zone of negative magnetic anomaly along the East part of the North Barents Basin. The AVO analysis of the anomalies of the seismic recording has allowed to allocate possible hydrocarbon reservoirs and to subdivide them into the gas-saturated and oil-gas-saturated.

  1. Crystallization and melting of biodegradable poly(propylene suberate)

    International Nuclear Information System (INIS)

    Highlights: → Thermal behavior of biodegradable polyester poly(propylene suberate) is discussed. → Tmo and ΔHmo were found 79.7 oC and 28.9 kJ/mol, respectively. → Banded spherulitic morphology was observed. → Crystallization regime II to III transition appears at 40 oC. → Interestingly Ozawa model for non-isothermal crystallization fits experimental data. - Abstract: Thermal behavior of poly(propylene suberate) (PPSub) was studied. PPSub is a novel biodegradable polyester which always shows lower crystallinity, and thus faster biodegradation, than poly(ε-caprolactone) or poly(butylene succinate). Crystalline structure, multiple melting behavior and re-crystallization of PPSub on heating were studied by using Wide Angle X-ray Diffraction (WAXD), Differential Scanning Calorimetry (DSC) and Step Scan DSC. The equilibrium melting point and the enthalpy of fusion of the pure crystalline polymer were found 79.7 oC and 28.9 kJ/mol, respectively. Polarized Light Microscopy (PLM) tests showed that PPSub forms banded spherulites. The Lauritzen-Hoffman theory was used. Values of spherulite growth rates and also overall crystallization rates after self-nucleation, from DSC data, were used. In the latter case the inverse of crystallization half times or the Avrami constant K values were supposed to be a measure of crystallization rates. Critical breakpoint in the Lauritzen-Hoffman plots appeared at 40 oC showing crystallization regime II to III transition. Non-isothermal crystallization kinetics was also analyzed. Interestingly, the Ozawa model seems to hold for PPSub. The iso-conversional method of Friedman was used to study the activation energy of PPSub crystallization on cooling and the Lauritzen-Hoffman parameters were also calculated by applying the Vyazovkin method.

  2. WESTERN EXTENSION OF THE SEVAN-AKERA SUTURE ZONE (ERZINCAN-ERZURUM REGION, TURKEY): COMPARISION OF NEW DATA CONCERNING ORIGIN, STRUCTURE AND TECTONIC EVOLUTION BETWEEN SEVAN-AKERA AND ERZINCAN SUTURE ZONES

    OpenAIRE

    Hässig, Marc; Rolland, Yann; Topuz, G.; Çelik, Ö.; Sosson, Marc

    2012-01-01

    In order to better understand the tectonic evolution of the Sevan-Akera suture zone, particularly its connection westward into the Ankara-Erzincan suture, field observations and sampling were carried out on the Erzincan suture zone (near Erzincan). The goal of this study is to solve the problem of linking both odbucted ophiolitic domains. As in Armenia, the structures in Turkey are complex and have been reworked and reactivated because of post-obduction collision stages. Still, field investig...

  3. Polypropylene film chemical and physical modifications by dielectric barrier discharge plasma treatment at atmospheric pressure.

    Science.gov (United States)

    Leroux, Frédéric; Campagne, Christine; Perwuelz, Anne; Gengembre, Léon

    2008-12-15

    Dielectric barrier discharge (DBD) technologies have been used to treat a polypropylene film. Various parameters such as treatment speed or electrical power were changed in order to determine the treatment power impact at the polypropylene surface. Indeed, all the treatments were performed using ambient air as gas to oxidize the polypropylene surface. This oxidation level and the surface modifications during the ageing were studied by a wetting method and by X-ray photoelectron spectroscopy (XPS). Moreover polypropylene film surface topography was analyzed by atomic force microscopy (AFM) in order to observe the surface roughness modifications. These topographic modifications were correlated to the surface oxidation by measuring with a lateral force microscope (LFM) the surface heterogeneity. The low ageing effects and the surface reorganization are discussed. PMID:18930244

  4. Long-term stability of irradiated polypropylene fibers and carboxylic cationites on their base

    International Nuclear Information System (INIS)

    Study is carried out of polypropylene fibers and fibrous carboxylic cationites on their base, which have been obtained by radiation graft polymerization of acrylic acid by the method of preliminary irradiation of polypropylene fibers on air (gamma-rays of 60Co, dose rate 0.37 Gy/s, dose 5-140 kGy). Mechanical and sorptive properties of polypropylene fibers and cationites are investigated after long-term storage in different conditions. The cationite obtained has excellent sorption properties towards cations of Cd, Pb, Cu. Zn, Fe and etc. It is shown that conditions of graft polymerization and storage influence on long-term stability of carboxylic cationites on the base of polypropylene fibers. It is pointed out that the use of cross-linking agent considerably increases long-term stability of grafted fibers

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

    International Nuclear Information System (INIS)

    Highlights: → Polypropylene montmorillonite (PP-MMT) produced at different processing conditions. → Polypropylene Nanocomposites with higher increase on impact resistance. → Higher enhancement on mechanical properties. - Abstract: Polypropylene montmorillonite (PP-MMT) nanocomposites have been prepared by using a co-rotating twin screw extruder. The effects of processing conditions at fixed clay content (5 wt%) on polymer properties were investigated by means of transmission electron microscopy (TEM), flexural modulus, izod impact, dynamic mechanical analysis (DMA), and differential scanning calorimetry (DSC). It was noticed that the morphology and the mechanical properties of polypropylene nanocomposites were affected by different screw shear configuration. The results showed that the higher enhancement on mechanical properties was obtained by medium shear intensity profile instead of high configuration. An exceptional increase (maximum of 282%) on impact resistance was observed.

  6. Fluid handling and fabric handle profiles of hydroentangled greige cotton and spunbond polypropylene nonwoven topsheets

    Science.gov (United States)

    Absorbent nonwoven topsheets are traditionally spunbond (or spunbond-meltblown (SM)) polypropylene nonwoven fabrics, and are used for a wide range of incontinence applications. Here we describe how nonwoven greige cotton demonstrates positive incontinence performance indices suitable for top sheet ...

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

    OpenAIRE

    Chapala. Venkata x Venkata Ramana; CH. Naga Sindhura

    2012-01-01

    This analysis study is done by using different types of fibres such as steel, glass and polypropylene with aspect ratio varying from 20 to 120 for steel, 600 to 860 for glass and 30 to 100 for polypropylene fibres.The total fibre percentages of 0 to 2�0for steel, 0 to 2�0for glass and 0 to 2.5�0for polypropylene with variation of 0.25�he design mix varying from M20 to M60 with water cement ratio 0.3 to 0.55 for steel, 0.16 to 0.55 for glass and 0.46 for polypropylene.After being cured under t...

  8. 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)

  9. Polypropylene laminated steel sheet usable without painting; Toso kotei shoryaku kanona poripuropiren raminato gohan

    Energy Technology Data Exchange (ETDEWEB)

    Yoshihara, R.; Wake, R.; Mizoguchi, R.; Miyoshi, K.; Nasuno, T.

    1998-05-31

    Painting with organic solves is shunned due to its environmental problems, and the lamination of steel with thermoplastic resins is being pursued in the canmaking industry. To meet this demand, Nippon Steel developed polypropylene-laminated steel sheet by the T-die lamination process that melt-extrudes polypropylene directly on steel sheet. Since the crystallization of polypropylene is controlled by optimizing the cooling conditions, a film with excellent formability and corrosion resistance is obtained. The polypropylene-laminated steel sheet is now commercially used for 18-liter cans. Their economy is expected to expand the application of T-die laminated steel sheets to include polyethylene and polyethylene terephthalate as laminating resins. (author)

  10. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Furlan, L.G. [Federal Institute of Rio Grande do Sul, IFRS, Campus Restinga, Estrada Joao Antonio da Silveira, 351, Porto Alegre 91790-400 (Brazil); Ferreira, C.I.; Dal Castel, C.; Santos, K.S.; Mello, A.C.E. [Chemistry Institute, Federal University of Rio Grande do Sul, UFRGS, Av. Bento Goncalves, 9500, Porto Alegre 91501-970 (Brazil); Liberman, S.A.; Oviedo, M.A.S. [Braskem S.A., III Polo Petroquimico, Via Oeste, Lote 5, Triunfo 95853-000 (Brazil); Mauler, R.S., E-mail: mauler@iq.ufrgs.br [Chemistry Institute, Federal University of Rio Grande do Sul, UFRGS, Av. Bento Goncalves, 9500, Porto Alegre 91501-970 (Brazil)

    2011-08-25

    Highlights: {yields} Polypropylene montmorillonite (PP-MMT) produced at different processing conditions. {yields} Polypropylene Nanocomposites with higher increase on impact resistance. {yields} Higher enhancement on mechanical properties. - Abstract: Polypropylene montmorillonite (PP-MMT) nanocomposites have been prepared by using a co-rotating twin screw extruder. The effects of processing conditions at fixed clay content (5 wt%) on polymer properties were investigated by means of transmission electron microscopy (TEM), flexural modulus, izod impact, dynamic mechanical analysis (DMA), and differential scanning calorimetry (DSC). It was noticed that the morphology and the mechanical properties of polypropylene nanocomposites were affected by different screw shear configuration. The results showed that the higher enhancement on mechanical properties was obtained by medium shear intensity profile instead of high configuration. An exceptional increase (maximum of 282%) on impact resistance was observed.

  12. Influence of suturing material on wound healing: Experimental study in dogs

    Directory of Open Access Journals (Sweden)

    Gazivoda Dragan

    2015-01-01

    Full Text Available Background/Aim. The most common materials implanted in the human organism are suture materials that are classified on the basis of several criteria, usually the origin, structure, and properties. The properties of suture materials are related to its absorbability and non-absorbability. When using resorbable materials it is of great importance to determine whether its absorbability and tensile strength help wound healing in function of time. Sutures themselves can become a source of inflammation, that may reduce or compromise the potential of reparation and regeneration. The aim of this experimental study on dogs was to ascertain whether the absorption rate and the degree of local tissue reactions differ from information provided by the manufacturers, whether there are differences between the applied suture materials and which of the used suture materials have better effect on wound healing. Methods. Experimental testing of the selected suture materials basic characteristics was performed on 6 German Shepherd dogs, which, after induction of general anesthesia, were made 3 identical incisions each in all 4 quadrants (left and right side of the upper and lower jaws, so that 12 horizontal incisions were formed, 10 mm long, 20-25 mm distant from one another, on each animal. Randomly, incisions were stitched up in the following order, starting from back to front: catgut, Dexon, Vicryl-Rapid. The experiment was terminated by histopathological examination of tissue samples, taken on postoperative day 3, 7, 14 and 21 in order to identify the effect of healing and the degree of local reaction. Results. The obtained results suggest that catgut has the highest absorption rate, while Dexon the lowest. Vicryl-Rapid causes the lowest level of local reactions, while Dexon the highest. Conclusion. There is no ideal suture material because various patient factors also influence the wound healing process.

  13. In Vitro Oral Biofilm Formation on Triclosan-Coated Sutures in the Absence and Presence of Additional Antiplaque Treatment

    OpenAIRE

    Venema, Sebastiaan; Abbas, Frank; van de Belt-Gritter, Betsy; van der Mei, Henny C.; Busscher, Henk J.; van Hoogmoed, Chris G.

    2011-01-01

    Purpose: This study evaluated the in vitro plaque inhibitory effect of triclosan-coated polyglactin 910 sutures in the absence and presence of an additional antiplaque agent commonly used after oral surgery. Materials and Methods: Triclosan-coated sutures were incubated for 4 hours in freshly collected human saliva and, when appropriate, subsequently treated with an antiplaque rinse containing chlorhexidine-cetyl pyridinium as active components. Sutures without a triclosan-coating served as a...

  14. Changes to the cell, tissue and architecture levels in cranial suture synostosis reveal a problem of timing in bone development

    Directory of Open Access Journals (Sweden)

    J Regelsberger

    2012-11-01

    Full Text Available Premature fusion of cranial sutures is a common problem with an incidence of 3-5 per 10,000 live births. Despite progress in understanding molecular/genetic factors affecting suture function, the complex process of premature fusion is still poorly understood. In the present study, corresponding excised segments of nine patent and nine prematurely fused sagittal sutures from infants (age range 3-7 months with a special emphasis on their hierarchical structural configuration were compared. Cell, tissue and architecture characteristics were analysed by transmitted and polarised light microscopy, 2D-histomorphometry, backscattered electron microscopy and energy-dispersive-x-ray analyses. Apart from wider sutural gaps, patent sutures showed histologically increased new bone formation compared to reduced new bone formation and osseous edges with a more mature structure in the fused portions of the sutures. This pattern was accompanied by a lower osteocyte lacunar density and a higher number of evenly mineralised osteons, reflecting pronounced lamellar bone characteristics along the prematurely fused sutures. In contrast, increases in osteocyte lacunar number and size accompanied by mineralisation heterogeneity and randomly oriented collagen fibres predominantly signified woven bone characteristics in patent, still growing suture segments. The already established woven-to-lamellar bone transition provides evidence of advanced bone development in synostotic sutures. Since structural and compositional features of prematurely fused sutures did not show signs of pathological/defective ossification processes, this supports the theory of a normal ossification process in suture synostosis – just locally commencing too early. These histomorphological findings may provide the basis for a better understanding of the pathomechanism of craniosynostosis, and for future strategies to predict suture fusion and to determine surgical intervention.

  15. LiquiBand® Surgical S topical adhesive versus sutures for the closure of laparoscopic wounds. A randomized controlled trial

    OpenAIRE

    Jan, Haider; Waters, Natasha; Haines, Pat; Kent, Andrew

    2013-01-01

    Cyanoacrylate adhesives offer the surgeon and patient an alternative to subcuticular suturing. LiquiBand® Surgical S (LBSS) is a new formulation with a blend of monomeric n-butyl and 2-octyl cyanoacrylates. In this study, the effectiveness, safety, and clinical utility of LBSS was compared to Vicryl™ sutures for the closure of laparoscopic incisions. This was a prospective randomized study of LBSS skin adhesive versus Vicryl™ sutures for the topical closure of laparoscopic surgical incisions....

  16. Thermo-oxidative ageing of polypropylene geosynthetics monitored by thermal analysis and mechancal tensile test

    OpenAIRE

    Bartolomeo, P; ASTRUC, A; MASSIEU, E; Barberis, N.; Lavaud, S.; BENNETON, JP

    2004-01-01

    The aim of this study is to monitor polypropylene ageing by means of thermal analysis. Thermal results are always compared to mechanical tensile tests so as to get both a chemical characterisation and a macroscopic measurement. Two polypropylene geosynthetics have been chosen, a fibre like one (geotextile) and a thick one (geomembrane). The annealing effects are studied first. Results of macroscopic mechanical loss are compared to chemical rearrangement obtained by DSC. Then, fiber are aged u...

  17. Long-Term Follow-up of Polypropylene Bone Anchored Slings

    OpenAIRE

    Patel, Bhavin N.; Emma Longo; Fred E. Govier; Kathleen C. Kobashi; Alvaro Lucioni

    2013-01-01

    Introduction The transvaginal bone anchored polypropylene sling (BAS) has proven to be a successful treatment for patients with SUI. However, there is limited data on long-term outcomes following BAS with polypropylene mesh. We report our series of patients who had at least 3 years of follow-up after placement of BAS. Materials and Methods A retrospective review of prospectively collected data of patients undergoing BAS for stress urinary incontinence (SUI) with minimum 3 year follow-up was...

  18. INVESTIGATION OF THE MORPHOLOGICAL AND THERMAL PROPERTIES OF WASTE NEWSPRINT/ RECYCLED POLYPROPYLENE/ NANOCLAY COMPOSITE

    OpenAIRE

    Mohammad Amin Danesh,; Hassan Ziaei Tabari,; Reza Hosseinpourpia; , Noradin Nazarnezhad,; Morteza Shams

    2012-01-01

    The main objective of this research was to study the potential of waste polypropylene and waste newsprint fiber for making wood-plastic nanocomposites. We used 30 wt.% waste newsprint fiber and 10 wt.% compatilizer in this study. Nanoclay was used at two levels: 2.5 and 5% by wt. Materials were mixed with either recycled or virgin polypropylene. The effects of nanoclay (NC) on the mechanical and thermal properties were also studied. The improvements in tensile properties of the blended compos...

  19. Development of a Halogen Free Flame Retardant Masterbatch for Polypropylene Fibers

    OpenAIRE

    François Rault; Stéphane Giraud; Fabien Salaün; Xavier Almeras

    2015-01-01

    The efficiency of new phosphinates, in combination with melamine cyanurate, was studied using different polypropylene textile structures. The influence of different ratios up to a total amount of 6 wt% in the polypropylene fiber was investigated using the limiting oxygen index (LOI) and cone calorimeter method for research purposes, while the performances were correlated to the standards FMVSS 302 (Federal Motor Vehicle Safety Standards) and DIN 4102-l (Deutsches Institut für Normung) used mo...

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

    OpenAIRE

    Fereshteh Mirjalili; Siamak Moradian; Farhad Ameri

    2013-01-01

    Attempts were made to modify polypropylene fibers by melt blending with polyethylene terephthalate in order to enhance the dyeability of the resultant fiber. Five blends of polypropylene/polyethylene terephthalate/compatibilizer were prepared and subsequently spun into fibers. Three disperse dyes were used to dye such modified fibers at boiling and 130°C. The dyeing performance of the blend fibers, as well as the morphological, chemical, thermal, and mechanical properties, of the correspondin...

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

    OpenAIRE

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

    2012-01-01

    The behavior of stone groundwood / polypropylene injection-molded composites was evaluated with and without coupling agent. Stone groundwood (SGW) is a fibrous material commonly prepared in a high yield process and mainly used for papermaking applications. In this work, the use of SGW fibers was explored as a reinforcing element of polypropylene (PP) composites. The surface charge density of the composite components was evaluated, as well as the fiber’s length and diameter inside the composit...

  2. Antimicrobial polymers from polypropylene/silver composites—Ag+ release measured by anode stripping voltammetry

    OpenAIRE

    Radheshkumar, C.; Münstedt, H

    2006-01-01

    Polypropylene/silver composites were subjected to silver ion release experiments in order to investigate their Ag+ release capabilities, a pertinent condition for antimicrobial efficacy. Polypropylene containing elementary silver powder having a specific surface area of 0.78 m2/g was considered as the principal antimicrobial filler. In addition the effectiveness of other commercial antimicrobials based on silver were also examined. Evidence is presented for the release of silver ions...

  3. A Phenomenological Thermal-Mechanical Viscoelastic Constitutive Modeling for Polypropylene Wood Composites

    OpenAIRE

    Xiongqi Peng; Hongling Yin; Jun Chen; Xue Liu

    2012-01-01

    This paper presents a phenomenological thermal-mechanical viscoelastic constitutive modeling for polypropylene wood composites. Polypropylene (PP) wood composite specimens are compressed at strain rates from 10−4 to 10−2 s−1 and at temperature of , , and , respectively. The mechanical responses are shown to be sensitive both to strain rate and to temperature. Based on the Maxwell viscoelastic model, a nonlinear thermal-mechanical viscoelastic constitutive model is developed for the PP wood co...

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

    OpenAIRE

    Božena Košíková; Juraj Lábaj

    2009-01-01

    The blending of polypropylene with lignin derived from chemical wood pulp manufacture makes it possible to prepare optically transparent films (thickness 50-60μm) 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 peripheral...

  5. Electrochemical Impedance Study of Zinc Yellow Polypropylene-Coated Aluminum Alloy

    OpenAIRE

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

    2010-01-01

    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...

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

    OpenAIRE

    Zhifeng Chen

    2009-01-01

    A parametric experimental study has been conducted to investigate the effect of polypropylene fiber on the shrinkage of cement-stabilized macadam. By means of the micrometer gauge method and the strain gauge method, the dry shrinkage coefficient and thermal shrinkage coefficient of cement-stabilized macadam were measured respectively. The results indicate that polypropylene fiber can effectively decrease the average dry shrinkage coefficient and average thermal shrinkage coefficient of cement...

  7. The effect of polypropylene fibres within concrete with regard to fire performance in structures

    OpenAIRE

    Richardson, Alan; Dave, Urmil V.

    2008-01-01

    Purpose – The purpose of this paper is to examine the effect of various polypropylene fibre additions (types and volume) to concrete with regard to explosive spalling when subject to high temperatures similar to those experienced in building or tunnel fires. Design/methodology/approach – Medium strength concrete was manufactured with varying proportions of polypropylene fibres. Plain control samples were used to determine the original concrete strength and this was used as a benchmark fo...

  8. Thermomechanical and Rheological Behaviours of Waste Glass Fibre-Filled Polypropylene Composites

    OpenAIRE

    Siriporn Damrongsukkul; Takeshi Kitano; Sarawut Rimdusit; Sunan Tiptipakorn

    2009-01-01

    The composites between the reinforced glass fibre wastes obtained from surfboard manufacturing industry and polypropylene were developed for value adding and environmental reasons. The thermomechanical and rheological behaviours of the composites were investigated. Glass fibre contents were varied from 5 to 30wt%. The effects of maleic anhydride grafted polypropylene (MA-PP) compatibilizer on the behaviours were also determined. The results revealed that the addition of glass fibre was able t...

  9. Electron beam irradiations of polypropylene syringe barrels and the resulting physical and chemical property changes

    International Nuclear Information System (INIS)

    Mechanical, thermal, chemical decomposition and electron spin resonance (ESR) methods were used to study electron beam irradiated polypropylene syringe barrels that were irradiated to a total fractionated dose of 0, 20, 40, 60, and 80 kGy (in steps of 20 kGy). Dose mapping was conducted to determine dose to and through the syringe barrel. Analysis of these data indicated that degradation of the polypropylene syringes increased with an increase in electron beam irradiation.

  10. Enhancement in Mechanical and Electrical Properties of Polypropylene Using Graphene Oxide Grafted with End-Functionalized Polypropylene

    Directory of Open Access Journals (Sweden)

    Patchanee Chammingkwan

    2016-03-01

    Full Text Available Terminally hydroxylated polypropylene (PP synthesized by a chain transfer method was grafted to graphene oxide (GO at the chain end. Thus obtained PP-modified GO (PP-GO was melt mixed with PP without the use of a compatibilizer to prepare PP/GO nanocomposites. Mechanical and electrical properties of the resultant nanocomposites and reference samples that contained graphite nanoplatelets, partially reduced GO, or fully reduced GO were examined. The best improvement in the tensile strength was obtained using PP-GO at 1.0 wt %. The inclusion of PP-GO also led to the highest electrical conductivity, in spite of the incomplete reduction. These observations pointed out that terminally hydroxylated PP covalently grafted to GO prevented GO layers from re-stacking and agglomeration during melt mixing, affording improved dispersion as well as stronger interfacial bonding between the matrix and GO.

  11. hermal Stability of Clay's Galleries in Polypropylene - Clay (montmorillonite Nanocomposites using Polypropylene-g-Maleic Anhydride as Compatibilizer

    Directory of Open Access Journals (Sweden)

    Pandu Lanang Kinasih

    2009-04-01

    Full Text Available Superior properties of food packaging can be achieved using nanocomposite technology. However, fabrication of this materials are complex and expensive. Long term objectives of this research is the synthesis of low cost polypropylene clay nanocomposites (PPCN via a short-cut method known as cascade engineering'. Cascade engineering principle in PPCN fabrication is performed by using compatibilizer (to enable the mixing of PP and clay masterbatch, and PPCN in one pot process using melt mixer. This paper present the experimental results using small-angle x-ray diffraction (XRD on the thermal stability of the PPCN. Results from the XRD analysis showed that the clay was intercalated, however no significant changes were observed as a result of variation in mixing time. XRD patterns of the annealed PPCN showed reduction of MMT's gallery (deintercalation These phenomenon was probably caused by insufficient bonding and lack of compatibility between PP-g-MA and MMT.

  12. 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.

  13. 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

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

    Scientific Electronic Library Online (English)

    Arieny, Rodrigues; Benjamim de M., Carvalho; Lus A., Pinheiro; Rosrio E. S., Brets; Sebastio V., Canevarolo; Juliano, Marini.

    Full Text Available Numerous studies have focused on polymer mixtures aimed at the potential applications of these materials. This work analyzed the effect of polymer reprocessing and the type and concentration of compatibilizer on the isothermal crystallization kinetics of polypropylene/wood flour composites. The comp [...] osites, which were polypropylene grafted with acrylic acid (PP-g-AA) and maleic anhydride (PP-g-MA), were processed in a twin screw extruder with and without compatibilizer. Reprocessed polypropylene reached complete crystallization in less time than the composites with virgin polypropylene. The addition of wood flour to the composites did not change the kinetics significantly compared to that of the pure polymers, but the compatibilizers did, particularly PP-g-AA. The nucleation exponent (n) and crystallization rate (K) were calculated from Avrami plots. The values of n ranged from 2 to 3, indicating instantaneous to sporadic nucleation. The crystallization half-time of reprocessed polypropylene was shorter than that of virgin polypropylene and of the compositions containing PP-g-AA compatibilizer. The activation energy of crystallization and the equilibrium melting temperature were calculated, respectively, from Arrhenius and Hoffman-Weeks plots. Both of these parameters showed lower values in the composites, particularly in the ones containing compatibilizers.

  15. 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.

  16. Photo-oxidative degradation of TiO2/polypropylene films

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Photo-oxidative degradation of polypropylene is accelerated by TiO2 incorporation. • Weight loss, FTIR, SEM and GPC shown high degree of degradation of polypropylene. • A mechanism of the photo-degradation of polypropylene by TiO2 is proposed. - Abstract: Photo-oxidative degradation of polypropylene films with TiO2 nanoparticles incorporated was studied in a chamber of weathering with Xenon lamps as irradiation source. TiO2 powder with crystalline structure of anatase was synthesized by thermal treatments at 400 and 500 °C starting from a precursor material obtained by sol–gel method. Composites of TiO2/polypropylene were prepared with 0.1, 0.5 and 1.0 wt% of TiO2. The mixture of components was performed using a twin screw extruder, the resulting material was pelletized by mechanical fragmenting and then hot-pressed in order to form polypropylene films with TiO2 dispersed homogeneously. Photo-oxidative degradation process was followed by visual inspection, weight loss of films, scanning electron microscopy (SEM), infrared spectroscopy with Fourier transformed (FTIR), and gel permeation chromatography (GPC)

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

    Directory of Open Access Journals (Sweden)

    Arieny Rodrigues

    2013-01-01

    Full Text Available Numerous studies have focused on polymer mixtures aimed at the potential applications of these materials. This work analyzed the effect of polymer reprocessing and the type and concentration of compatibilizer on the isothermal crystallization kinetics of polypropylene/wood flour composites. The composites, which were polypropylene grafted with acrylic acid (PP-g-AA and maleic anhydride (PP-g-MA, were processed in a twin screw extruder with and without compatibilizer. Reprocessed polypropylene reached complete crystallization in less time than the composites with virgin polypropylene. The addition of wood flour to the composites did not change the kinetics significantly compared to that of the pure polymers, but the compatibilizers did, particularly PP-g-AA. The nucleation exponent (n and crystallization rate (K were calculated from Avrami plots. The values of n ranged from 2 to 3, indicating instantaneous to sporadic nucleation. The crystallization half-time of reprocessed polypropylene was shorter than that of virgin polypropylene and of the compositions containing PP-g-AA compatibilizer. The activation energy of crystallization and the equilibrium melting temperature were calculated, respectively, from Arrhenius and Hoffman-Weeks plots. Both of these parameters showed lower values in the composites, particularly in the ones containing compatibilizers.

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

    Directory of Open Access Journals (Sweden)

    Chapala. Venkata x Venkata Ramana

    2012-12-01

    Full Text Available This analysis study is done by using different types of fibres such as steel, glass and polypropylene with aspect ratio varying from 20 to 120 for steel, 600 to 860 for glass and 30 to 100 for polypropylene fibres.The total fibre percentages of 0 to 2�0for steel, 0 to 2�0for glass and 0 to 2.5�0for polypropylene with variation of 0.25�he design mix varying from M20 to M60 with water cement ratio 0.3 to 0.55 for steel, 0.16 to 0.55 for glass and 0.46 for polypropylene.After being cured under the standard conditions for age of 28 days the specimens of each mixture were tested to determine the corresponding flexural strength. The parameters such as grade of concrete, aspect ratio, volume fraction and tensile strength of fibre for steel, glass and polypropylene fibres respectively, while the flexural strength of the concrete were chosen as output variable. The results obtained from the model and the experiments were compared by using regression analysis, and it was check in artificial neural networks. Finally form an empirical relation between flexural strength tograde of concrete, aspect ratio, volume fraction and tensile strength of fibre for steel, glass and polypropylene fibres.

  19. Can Suture Repair of ACL Transection Restore Normal Anteroposterior Laxity of the Knee? An Ex Vivo Study

    Science.gov (United States)

    Fleming, Braden C.; Carey, James L.; Spindler, Kurt P.; Murray, Martha M.

    2009-01-01

    INTRODUCTION Recent work has suggested the transected ACL can heal and support reasonable loads if repaired with sutures and a bioactive scaffold; however, use of a traditional suture configuration results in knees with increased AP laxity. The objective was to determine whether one of five different suture repair constructs when performed at two different joint positions would restore normal AP knee laxity. METHODS AP laxity of the porcine knee at 60 of flexion was evaluated for five suture repair techniques. Femoral fixation for all repair techniques utilized a suture anchor. Primary repair was to either the tibial stump, one of three bony locations in the ACL footprint, or a hybrid bony fixation. All five repairs were tied with the knee in first 30 and then 60 of flexion for a total of 10 repair constructs. RESULTS Suture repair to bony fixation points within the anterior half of the normal ACL footprint resulted in knee laxity values within 0.5 mm of the ACL-intact joint when the sutures were tied with the knee at 60 flexion. Suture repair to the tibial stump, or with the knee at 30 of flexion, did not restore normal AP laxity of the knee. CONCLUSIONS Three specific suture repair techniques for the transected porcine ACL restored the normal AP laxity of the knee at the time of surgery. Additional studies defining the changes in laxity with cyclic loading and in vivo healing are indicated. PMID:18528857

  20. Visibility of sutures of the orbit and periorbital region using multidetector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Gufler, Hubert; Preis, Markus; Koesling, Sabrina [Dept. of Diagnostic Radiology, Martin-Luther-University Halle-Wittenberg, Halle (Germany)

    2014-12-15

    Knowledge of cranial suture morphology is crucial in emergency medicine, forensic medicine, and maxillofacial reconstructive surgery. This study assessed the visibility of sutures of the orbit and periorbital region on multidetector computed tomography. Multidetector computed tomography scans of 200 patients (127 males, 73 females; mean age 51.3 years; range, 6-92 years) were evaluated retrospectively. The slice thicknesses varied from 0.5 to 1 mm, and the tube current from 25 to 370 mAs, depending on the CT indication. The visibility of sutures was estimated according to a 4-point scale from 'not visible to well visible' The chi-squared test was used to test the association of the visibility of sutures with the slice thickness, tube current, and age of patients. Statistical significance was assumed at p < 0.05. Overall, best visibility was found for the sutura frontozygomatica (98%), sutura frontonasalis (88.5%), and sutura sphenozygomatica (71.5%), followed by the sutura zygomaticomaxillaris (65.8%), sutura temporozygomatica (41.8%), sutura frontomaxillaris (44.5%), and sutura sphenofrontalis (31%). Poor visibility was found for the sutura frontolacrimalis (16.8%) and sutura frontoethmoidalis (1.3%). The sutura ethmoidomaxillaris, sutura lacrimomaxillaris, and sutura ethmoidolacrimalis were not visible. Although the sutures of the superior, lateral, and inferior orbit are well visible, those of the medial orbit are poorly visible on CT scans.

  1. Post operation recurrence of inguinal hernia in children and its relation with suture material

    Directory of Open Access Journals (Sweden)

    Omid Amanollahi

    2011-09-01

    Full Text Available Background: Using non-absorbable suture in children hernia repair to decrease of recurrence is recommended in the most pediatric surgery centers. The aim of this study was to determine relationship between kind of suture material and rate of hernia recurrence. Methods: In this clinical trial 200 children (age 1-5 years with inguinal hernia who operated in Imam-Reza Hospital (kermanshah Iran Between April 2007 until April 2008 enrolled into the study. Cases were selected by convenience sampling method and then randomly divided into two groups (100 cases per group and operated with absorbable (silk 3-0 and non-absorbable (vicryli 3-0 suture material. Following period was 12 months after operation and collected data analyzed by statistical software. Emergency operations were excluded from the study.Results: 83% of patients were boy and 17% were girl. %53 showed right side inguinal, 29% left side and %18 were bilateral hernia. After one year follow up only one case of recurrence was observed in each group.Conclusion: Our study confirmed that recurrence of inguinal hernia in children after surgery, is not related to kind of suture material (absorbability and we didnt find any significant difference. Other factors than suture material may influence recurrence rate of hernia operation in children.

  2. Upper Mantle Structure Around the Trans-European Suture Zone

    Science.gov (United States)

    Janutyte, Ilma; Majdanski, Mariusz; Voss, Peter H.; Kozlovskaya, Elena

    2014-05-01

    The Trans-European Suture Zone (TESZ) is the transition between old Proterozoic lithosphere in Northern and Eastern Europe and the younger Phanerozoic lithosphere in Central and Western Europe. The presented study is a part of the PASSEQ 2006-2008 project which is linked to the TOR project realized during 1996-1997. The PASSEQ and the TOR projects aimed to study the lithosphere and asthenosphere structure around the TESZ, but the latter was focused on the northwestern part of the TESZ between Sweden and Denmark - Germany, while the PASSEQ project was focused on the TESZ mainly beneath Poland. During the PASSEQ project 139 short-period and 49 broadband temporary seismic stations were deployed along the transect stretching from Germany throughout Czech Republic and Poland to Lithuania. The array recorded continuous seismic data from May, 2006 to June, 2008. In our study we used data of all available PASSEQ seismic stations and seismic stations of the national seismological networks of the participating countries and compiled a data set of teleseismic P-wave arrivals. The full data set consists of 8308 manually picked arrivals. Due to limited computational power we used the data of the highest quality only, i.e. 6008 picks. The non-linear teleseismic tomography algorithm TELINV was used to obtain the model of P-wave velocity perturbations in the upper mantle around the TESZ. We recovered the upper mantle structure from 70 km down to 350 km in the study area. The results show ±6.5 % P-wave velocity variations compared to the IASP91 velocity model. We found higher velocities beneath the old East European Craton (EEC) east of the TESZ and lower ones beneath the younger Western Europe west of the TESZ. The thickest litosphere was found beneath the EEC (Lithuania) where the higher velocities continue to about 300 km or even more. To the west of the TESZ under the Variscides the average depth of the lithosphere-asthenosphere boundary (LAB) is about 100 km. The TESZ appears as an intermediate tectonic structure between the EEC and Western Europe, with the asthenospere at a depth of 150-180 km. The LAB in the northern part of the TESZ has a shape of the ramp dipping NE direction at an angle of about 30 degrees. In the southern part of the TESZ the LAB is shallower, most probably due to younger tectonic settings.

  3. Light-guided localization within tissue using biocompatible surgical suture fiber as an optical waveguide

    Science.gov (United States)

    Choi, Woo June; Park, Kwan Seob; Lee, Byeong Ha

    2014-09-01

    In breast-conserving surgery, an optical wire is a useful surgical guiding tool to optically locate small lesions within the breast tissue. However, the use of a long silica glass fiber as the optical wire can be burdensome to patients because of its stiffness and nonbiocompatibility. We investigate the use of a biocompatible fiber for light localization in tissue. A surgical suture with a diameter of 400 ?m and a few centimeters long is employed as the biocompatible optical waveguide to transport the visible laser light to the inner tissue site. Optical location is confirmed with glow ball-like red laser illumination at the tip of the suture embedded within a fresh chicken breast tissue. Effective optical power coupling to the suture is made by using a double-cladding fiber coupler. From this preliminary result, we realize practical light localization with biopolymer waveguides.

  4. Precision of suture placement with microscope- and loupe-assisted anastomoses.

    Science.gov (United States)

    Rooks, M D; Slappey, J; Zusmanis, K

    1993-01-01

    Twenty-eight anastomoses involving seven surgeons were done on 2 mm Gortex vascular prostheses to test the effect of magnification on the precision of suture placement. One-half were done with 3.5-4x prism loupe magnification and the other one-half with 8-30x microscope magnification. The variability of suture placement (defined here as precision) was measured in a blinded fashion. The mean suture puncture to prosthesis edge measurement for the microscope-assisted group was approximately 0.03 mm closer to the edge. The variability from the mean for the microscope-assisted group was approximately 0.01 mm less than that for the loupe-assisted group. This difference was statistically significant at a P value of 0.0123. PMID:8271935

  5. Clinical research on application of adjustable sutures in glaucoma filtering operation

    Directory of Open Access Journals (Sweden)

    Zhi-Hua He

    2014-10-01

    Full Text Available AIM:To discuss the application effect of adjustable sutures in glaucoma filtering operation after trabecular resection. METHODS: Seventy-eight cases(101 eyessuffered from glaucoma were randomly divided into two groups, observation group and control group. Thirty-nine cases(51 eyesin the observation group underwent trabeculectomy with adjustable sutures, the control group(39 cases, 50 eyesonly adopted trabeculectomy.RESULTS: Compared Preoperative IOP in two groups, the difference was not statistically significant(P>0.05. After 6mo, IOP were decreased compared with preoperative in two groups, and that in observation group was lower than control group, the difference was statistically significant(PPCONCLUSION: The adjustable sutures combined with trabeculectomy for glaucoma can significantly reduce the postoperative complications. The curative effect is exact and clinically applicable.

  6. Retention sutures in traumatic retinal detachment surgery complicated by absence of an irido-lenticular diaphragm

    Directory of Open Access Journals (Sweden)

    E. P. Gurmizov

    2014-07-01

    Full Text Available Purpose: to determine of the surgical approach at patients with traumatic retinal detachment complicated by absence of an irido- lenticular diaphragm.Methods: One-stage surgical treatment with use retention sutures at the patient with traumatic retinal detachment which have resulted a contusion of an eyeball, complicated by rupture on ceratotomic to notches with loss iris and a crystalline lens.Results: Carrying out retention sutures in surgery traumatic retinal detachment complicated by absence of an irido-lenticular diaphragm provides correct position of silicone in vitreal cavities.Сonclusion: Retention sutures at the patient with traumatic retinal detachment at absence of an irido-lenticular diaphragm preventa silicone exit in the anterior chamber and development typical complications connected with it.

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

    DEFF Research Database (Denmark)

    Thorstad, Eva B.; Økland, Finn; Westerberg, Håkan; Aarestrup, Kim; Metcalfe, Julian D.

    2013-01-01

    Effects of implanting data-storage tags in European eel, Anguilla anguilla, and the suitability of different suture materials (braided permanent silk, permanent monofilament, absorbable and absorbable antibacterial) were examined. The tags consisted of an electronic unit and three floats on a wire......, making them flexible and able to follow the swimming movements of the eel. No mortality occurred, and tagged fish did not differ from the control fish in growth. Sutures were shed or dissolved slowly. After 4 weeks, there was no difference among the groups in the proportion of sutures left. After 6....... 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...

  8. Suture granuloma mimicking a recurrent sacro-coccygeal pilonidal sinus after Limberg flap.

    Science.gov (United States)

    Ardelt, Michael; Dittmar, Yves; Schulz, Birte; Rauchfuss, Falk; Scheuerlein, Hubert; Settmacher, Utz

    2014-12-01

    Sacro-coccygeal pilonidal sinus disease is classified as an asymptomatic, acutely abscess-forming or chronic subcutaneous inflammation in the sacro-coccygeal region featuring characteristic pits in the bottom cleft. Due to high rates of recurrence, two flap techniques have been established in the course of the past three decades. One of them is the Karydakis operation, the other option is a rotation flap named Limberg procedure. We report about a case of suture granuloma in the area of a Limberg flap after recurrent pilonidal sinus with extrusion of the suture material, thus mimicking recurrence. In case of recurrent pilonidal sinus following plastic coverage or primary closure, respectively, the differential diagnosis of suture granuloma should be considered. PMID:25124966

  9. Deep electromagnetic (MT and AMT) sounding of the suture zones of the Ukrainian shield

    Science.gov (United States)

    Antsiferov, A. V.; Sheremet, E. M.; Nikolaev, Yu. I.; Nikolaev, I. Yu.; Setaya, L. D.; Antsiferov, V. A.; Omelchenko, Al. A.

    2011-01-01

    The article discusses the results of deep magnetotelluric sounding of suture zones in the Precambrian structures of the Ukrainian shield in the context of collisional settings. All the considered suture zones (Orekhovo-Pavlograd, West Ingulets-Krivoi Rog, Golovanevsk-Yadlov-Traktemir, Nemirov-Kocherov or Brusilov) are associated with the regional anomalies of increased electric conductivity, which mark deep fault zones and characterize collisional settings. The nature of such deep anomalies might be due to the transport of the ore components together with the fluids from the crust and the mantle during the tectonomagmatic activation, which offers the possibility to predict the prospective areas of endogenic mineralization. A correlation has been established between the endogenic ore deposits located close to or within the suture zones and the low-resistivity anomalies.

  10. Osterix/Sp7 limits cranial bone initiation sites and is required for formation of sutures.

    Science.gov (United States)

    Kague, Erika; Roy, Paula; Asselin, Garrett; Hu, Gui; Simonet, Jacqueline; Stanley, Alexandra; Albertson, Craig; Fisher, Shannon

    2016-05-15

    During growth, individual skull bones overlap at sutures, where osteoblast differentiation and bone deposition occur. Mutations causing skull malformations have revealed some required genes, but many aspects of suture regulation remain poorly understood. We describe a zebrafish mutation in osterix/sp7, which causes a generalized delay in osteoblast maturation. While most of the skeleton is patterned normally, mutants have specific defects in the anterior skull and upper jaw, and the top of the skull comprises a random mosaic of bones derived from individual initiation sites. Osteoblasts at the edges of the bones are highly proliferative and fail to differentiate, consistent with global changes in gene expression. We propose that signals from the bone itself are required for orderly recruitment of precursor cells and growth along the edges. The delay in bone maturation caused by loss of Sp7 leads to unregulated bone formation, revealing a new mechanism for patterning the skull and sutures. PMID:26992365

  11. Performance Assessment of Suture Type in Juvenile Chinook Salmon Surgically Implanted with Acoustic Transmitters

    Energy Technology Data Exchange (ETDEWEB)

    Deters, Katherine A.; Brown, Richard S.; Carter, Kathleen M.; Boyd, James W.

    2009-02-27

    The objective of this study was to determine the best overall suture material to close incisions from the surgical implantation of Juvenile Salmon Acoustic Telemetry System (JSATS) acoustic microtransmitters in subyearling Chinook salmon Oncorhynchus tshawytscha. The effects of seven suture materials, four surgeons, and two water temperatures on suture retention, incision openness, tag retention, tissue inflammation, and tissue ulceration were quantified. The laboratory study, conducted by researchers at the Pacific Northwest National Laboratory, supports a larger effort under way for the U.S. Army Corps of Engineers, Portland District, aimed at determining the suitability of acoustic telemetry for estimating short- and longer-term (30-60 days) juvenile-salmonid survival at Columbia and Snake River dams and through the lower Columbia River.

  12. NON ABSORBABLE INTERMITTENT MATTRESS SUTURES IN THE MANAGEMENT OF AURICULAR HAEMATOMA

    Directory of Open Access Journals (Sweden)

    Muralidhar Reddy

    2014-12-01

    Full Text Available Auricular haematoma of pinna usually occurs secondary to trauma. If left untreated usually result in a deformity known as cauliflower ear. Various treatments are employed so as to produce the best cosmetic results. The aim of this article was to evaluate the outcome and complications of the treatment of auricular haematoma using non-absorbable 3-0 prolene intermittent sutures. This study has been performed upon eight patients presented with auricular haematoma at tertiary center, Govt. ENT Hospital, Koti, Hyderabad between August 2013 to August 2014. Follow up was continued for 6 months. The commonest cause behind auricular haematoma was personal insult. It was found that incision and drainage followed by suturing with non-absorbable intermittent mattress sutures appear to be simple, well tolerated and excellent method in treatment and preventing re-accumulation of auricular haematoma and to avoid ear deformity (Cauliflower ear.

  13. Evaluation of foaming polypropylene modified with ramified polymer

    Science.gov (United States)

    Demori, Renan; de Azeredo, Ana Paula; Liberman, Susana A.; Mauler, Raquel S.

    2015-05-01

    Polypropylene foams have great industrial interest because of balanced physical and mechanical properties, recyclability as well as low material cost. During the foaming process, the elongational forces applied to produce the expanded polymer are strong enough to rupture cell walls. As a result, final foam has a high amount of coalesced as well as opened cells which decreases mechanical and also physical properties. To increase melt strength and also avoid the coalescence effect, one of the current solution is blend PP with ramified polymers as well as branched polypropylene (LCBPP) or ethylene-octene copolymer (POE). In this research to provide extensional properties and achieve uniform cellular structures of expanded PP, 20 phr of LCBPP or POE was added into PP matrix. The blend of PP with ramified polymers was prepared by twin-screw extrusion. Injection molding process was used to produce PP foams using azodicarbonamide (ACA) as chemical blowing agent. The morphological results of the expanded PP displayed a non-uniform geometrical cell, apparent density of 0.48 g/cm3 and cell density of 13.9.104 cell/cm3. Otherwise, the expanded PP blended with LCBPP or POE displayed a homogeneous cell structure and increased the amount of smaller cells (50-100 ?m of size). The apparent density slightly increased with addition of LCBPP or POE, 0.64 and 0.57 g/cm3, respectively. Thus, the cell density reduced to 65% in PP/LCBPP 100/20 and 75% in the sample PP/POE 100/20 compared to expanded PP. The thermo-mechanical properties (DMTA) of PP showed specific stiffness of 159 MPa.cm-3.g-1, while the sample PP/LCBPP 100/20 increased the stiffness values of 10%. Otherwise, the expanded PP/POE 100/20 decreased the specific stiffness values at -30%, in relation to expanded PP. In summary, blending PP with ramified polymers showed increasing of the homogenous cellular structure as well as the amount of smaller cells in the expanded material.

  14. Flexor tendon repair: a comparative study between a knotless barbed suture repair and a traditional four-strand monofilament suture repair.

    LENUS (Irish Health Repository)

    Joyce, C W

    2014-01-01

    We compared the tensile strength of a novel knotless barbed suture method with a traditional four-strand Adelaide technique for flexor tendon repairs. Forty fresh porcine flexor tendons were transected and randomly assigned to one of the repair groups before repair. Biomechanical testing demonstrated that the tensile strengths between both tendon groups were very similar. However, less force was required to create a 2 mm gap in the four-strand repair method compared with the knotless barbed technique. There was a significant reduction in the cross-sectional area in the barbed suture group after repair compared with the Adelaide group. This would create better gliding within the pulley system in vivo and could decrease gapping and tendon rupture.

  15. Leyla loop: a time-saving suture technique for robotic atrial closure

    OpenAIRE

    K?l?, Leyla; ?enay, ?ahin; A. mit Gll; Alhan, Cem

    2013-01-01

    The longer durations of cardiopulmonary bypass and aortic cross-clamp times remain the disadvantages of robotic or minimally invasive cardiac surgery. For this reason, every small contribution to speeding up these procedures is of the utmost importance. Here, we present a practical, easy and time-saving suture technique for atrial closure. It consists of a hand-made loop at one end of the suture and saves the time otherwise consumed by knotting. It may also be used during conventional or mini...

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

    DEFF Research Database (Denmark)

    Jorgensen, L N; Sommer, T; Assaadzadeh, S; Strand, L; Dorfelt, A; Hensler, Margaret Kathryn; Rosenberg, J; Sommer, Thorbjørn

    2012-01-01

    BACKGROUND: Many patients develop discomfort after open repair of a groin hernia. It was hypothesized that suture fixation of the mesh is a cause of these symptoms. METHODS: This patient- and assessor-blinded randomized multicentre clinical trial compared a self-gripping mesh (Parietene Progrip...... differences between the groups in postoperative complications (33·7 versus 40·4 per cent; P = 0·215), rate of recurrent hernia within 1 year (1·2 per cent in both groups) or quality of life. CONCLUSION: The avoidance of suture fixation using a self-gripping mesh was not accompanied by a reduction in chronic...

  17. Image-based tracking of the suturing needle during laparoscopic interventions

    Science.gov (United States)

    Speidel, S.; Kroehnert, A.; Bodenstedt, S.; Kenngott, H.; Mller-Stich, B.; Dillmann, R.

    2015-03-01

    One of the most complex and difficult tasks for surgeons during minimally invasive interventions is suturing. A prerequisite to assist the suturing process is the tracking of the needle. The endoscopic images provide a rich source of information which can be used for needle tracking. In this paper, we present an image-based method for markerless needle tracking. The method uses a color-based and geometry-based segmentation to detect the needle. Once an initial needle detection is obtained, a region of interest enclosing the extracted needle contour is passed on to a reduced segmentation. It is evaluated with in vivo images from da Vinci interventions.

  18. Energy harvesting from vibration with cross-linked polypropylene piezoelectrets

    Directory of Open Access Journals (Sweden)

    Xiaoqing Zhang

    2015-07-01

    Full Text Available Piezoelectret films are prepared by modification of the microstructure of polypropylene foam sheets cross-linked by electronic irradiation (IXPP, followed by proper corona charging. Youngs modulus, relative permittivity, and electromechanical coupling coefficient of the fabricated films, determined by dielectric resonance spectra, are about 0.7 MPa, 1.6, and 0.08, respectively. Dynamic piezoelectric d33 coefficients up to 650 pC/N at 200 Hz are achieved. The figure of merit (FOM, d33 ? g33 for a more typical d33 value of 400 pC/N is about 11.2 GPa?1. Vibration-based energy harvesting with one-layer and two-layer stacks of these films is investigated at various frequencies and load resistances. At an optimum load resistance of 9 M? and a resonance frequency of 800 Hz, a maximum output power of 120 ?W, referred to the acceleration g due to gravity, is obtained for an energy harvester consisting of a one-layer IXPP film with an area of 3.14 cm2 and a seismic mass of 33.7 g. The output power can be further improved by using two-layer stacks of IXPP films in electric series. IXPP energy harvesters could be used to energize low-power electronic devices, such as wireless sensors and LED lights.

  19. Energy harvesting from vibration with cross-linked polypropylene piezoelectrets

    Science.gov (United States)

    Zhang, Xiaoqing; Wu, Liming; Sessler, Gerhard M.

    2015-07-01

    Piezoelectret films are prepared by modification of the microstructure of polypropylene foam sheets cross-linked by electronic irradiation (IXPP), followed by proper corona charging. Young's modulus, relative permittivity, and electromechanical coupling coefficient of the fabricated films, determined by dielectric resonance spectra, are about 0.7 MPa, 1.6, and 0.08, respectively. Dynamic piezoelectric d33 coefficients up to 650 pC/N at 200 Hz are achieved. The figure of merit (FOM, d33 ? g33) for a more typical d33 value of 400 pC/N is about 11.2 GPa-1. Vibration-based energy harvesting with one-layer and two-layer stacks of these films is investigated at various frequencies and load resistances. At an optimum load resistance of 9 M? and a resonance frequency of 800 Hz, a maximum output power of 120 ?W, referred to the acceleration g due to gravity, is obtained for an energy harvester consisting of a one-layer IXPP film with an area of 3.14 cm2 and a seismic mass of 33.7 g. The output power can be further improved by using two-layer stacks of IXPP films in electric series. IXPP energy harvesters could be used to energize low-power electronic devices, such as wireless sensors and LED lights.

  20. Electromagnetic interference shielding effectiveness of polypropylene/conducting fiber composites

    Science.gov (United States)

    Lee, Pyoung-Chan; Kim, Bo-Ram; Jeoung, Sun Kyoung; Kim, Yeung Keun

    2016-03-01

    Electromagnetic released from the automotive electronic parts is harmful to human body. Electromagnetic interference (EMT) shielding refers to the reflection and/or adsorption of electromagnetic radiation by a material, which thereby acts as a shield against the penetration of the radiation through the shield. Polypropylene (PP)/conductive micro fiber composites containing various fiber contents and fiber length were injection-molded. The effect of fiber content and length on electrical properties of the composites was studied by electrical resistivity and EMT shielding measurements. The through-plane electrical conductivity and dielectric permittivity were obtained by measuring dielectric properties. The EMT shielding effectiveness (SE) was investigated by using S-parameter in the range of 100 ~ 1500 MHz. Reflection, absorption and multiple-reflection are the EMT attenuation mechanisms. From the measurement of S-Parameters, the absorption coefficient, reflection coefficient, and the shielding efficiency of the materials were calculated. The EMT SE of PP/conducing fiber composites is 40 dB over a wide frequency range up to 1.5 GHz, which is higher than that of PP/talc composite used automotive parts, viz. 0 dB.

  1. Isotactic polypropylene carbon nanotube composites -- crystallization and ordering behavior

    Science.gov (United States)

    Georgiev, Georgi; Judith, Robert; Gombos, Erin; McIntyre, Michael; Schoen, Scott; Cebe, Peggy; Mattera, Michael

    2010-03-01

    The field of Polymer Nanocomposites (PNCs) is growing steadily in recent years. We use carbon nanotubes (CNTs) to affect the crystallization behavior of the polymers. Isotactic Polypropylene (iPP) is very widely used and is a good model system to understand the physics of other similar polymers. iPP/CNT PNCs form α, β, and γ crystallographic phases under a variety of crystallization conditions: non-isothermal and isothermal melt crystallization, shear, stress, fiber extrusion, etc. The crystal growth is altered from spherulitic to α-fibrillar upon the nucleation effect of CNTs. We are studying the effect of different temperature treatment schemes and different isothermal crystallization conditions. We found also that the smectic ordering in iPP is improved by the introduction of CNTs. We use Differential Scanning Calorimetry, Wide Angle X-ray scattering, Microscopic Transmission Ellipsometry and Avrami analysis. Research supported by: Assumption College Faculty Development Grant, funding for students' stipends, instrumentation and supplies, the NSF Polymers Program of the DMR, grant (DMR-0602473) and NASA grant (NAG8-1167).

  2. Mapping physicochemical surface modifications of flame-treated polypropylene

    Directory of Open Access Journals (Sweden)

    S. Farris

    2014-04-01

    Full Text Available The aim of this work was to investigate how the surface morphology of polypropylene (PP is influenced by the surface activation mediated by a flame obtained using a mixture of air and propane under fuel-lean (equivalence ratio φ = 0.98 conditions. Morphological changes observed on flamed samples with smooth (S, medium (M, and high (H degree of surface roughness were attributed to the combined effect of a chemical mechanism (agglomeration and ordering of partially oxidized intermediate-molecular-weight material with a physical mechanism (flattening of the original roughness by the flame’s high temperature. After two treatments, the different behavior of the samples in terms of wettability was totally reset, which made an impressive surface energy of ~43 mJ•m–2 possible, which is typical of more hydrophilic polymers (e.g., polyethylene terephthalate – PET. In particular, the polar component was increased from 1.21, 0.08, and 0.32 mJ•m–2 (untreated samples to 10.95, 11.20, and 11.17 mJ•m–2 for the flamed samples S, M, and H, respectively, an increase attributed to the insertion of polar functional groups (hydroxyl and carbonyl on the C–C backbone, as demonstrated by the X-ray photoelectron spectroscopy results.

  3. Polypropylenes foam consisting of thermally expandable microcapsule as blowing agent

    Science.gov (United States)

    Jeoung, Sun Kyung; Hwang, Ye Jin; Lee, Hyun Wook; Kwak, Sung Bok; Han, In-Soo; Ha, Jin Uk

    2016-03-01

    The structure of thermally expandable microcapsule (TEMs) is consisted of a thermoplastic shell which is filled with liquid hydrocarbon at core. The shell of TEMs becomes soft when the temperature is higher than boiling temperature of liquid hydrocarbon. The shell of TEMs is expanded under the high temperature because the inner pressure of TEMs is increased by vaporization of hydrocarbon core. Therefore, the TEMs are applicable for blowing agents and light weight fillers. In this research, we fabricated the polypropylene (PP) foam by using the TEMs and chemical blowing agents and compared to their physical properties. The density of the specimen was decreased when the contents of chemical blowing agents and TEMs were increased. In addition, the mechanical properties (i.e. tensile strength and impact strength) of specimens were deteriorated with increasing amount of chemical blowing agents and TEMs. However, PP foam produced with TEMs showed higher impact strength than the one with the chemical blowing agent. In order to clarify the dependence of impact strength of PP foam as the blowing agent, the morphology difference of the PP foams was investigated. Expanding properties of PP foams produced with TEMs was changed with TEMs content of PP foams. Processing conditions also influenced the mechanical properties of PP foam containing TEMs.

  4. Effect of crystallinity on the viscosity of an isotactic polypropylene

    Science.gov (United States)

    Pantani, Roberto; De Meo, Annarita; Speranza, Vito; Titomanlio, Giuseppe

    2015-12-01

    In polymer processing the description of solidification has an extreme significance. For semi crystalline polymers solidification takes place with an increase of crystallinity that strongly influences the viscosity. An increase of crystallinity rather than the temperature decrease causes an increase of viscosity. In this work an isotactic polypropylene, well characterized in terms of crystallization kinetics in both quiescent and flow conditions, was subjected to short steps of shear in isothermal conditions, and the evolution of viscosity was then followed during time. It was found that, for the same shear rate, an increase of the duration of the shear step induced an anticipated hardening of the material, caused by a faster crystallization. A model for flow-induced crystallization was applied to describe the crystallinity evolution during the tests, and a model for the effect of crystallinity on viscosity was used to describe the hardening. On the basis of the results obtained, it was noticed that the effect of crystallinity on viscosity is largely determined by the volume occupation of crystalline structure, whereas the size of the spherulites seems to be much less significant.

  5. Materials characterization of explanted polypropylene hernia mesh: Patient factor correlation.

    Science.gov (United States)

    Smith, Sarah E; Cozad, Matthew J; Grant, David A; Ramshaw, Bruce J; Grant, Sheila A

    2016-02-01

    This study quantitatively assessed polypropylene (PP) hernia mesh degradation and its correlation with patient factors including body mass index, tobacco use, and diabetes status with the goal of improving hernia repair outcomes through patient-matched mesh. Thirty PP hernia mesh explants were subjected to a tissue removal process followed by assessment of their in vivo degradation using Fourier transform infrared, differential scanning calorimetry, and thermogravimetric analysis analyses. Results were then analyzed with respect to patient factors (body mass index, tobacco use, and diabetes status) to determine their influence on in vivo hernia mesh oxidation and degradation. Twenty of the explants show significant surface oxidation. Tobacco use exhibits a positive correlation with modulated differential scanning calorimetry melt temperature and exhibits significantly lower TGA decomposition temperatures than non-/past users. Chemical and thermal characterization of the explanted meshes indicate measurable degradation while in vivo regardless of the patient population; however, tobacco use is correlated with less oxidation and degradation of the polymeric mesh possibly due to a reduced inflammatory response. PMID:26454268

  6. Antistatic modification of polypropylene by incorporating Tween/modified Tween

    Science.gov (United States)

    Zheng, Anna; Xu, Xiang; Xiao, Huining; Li, Na; Guan, Yong; Li, Shuzhao

    2012-09-01

    Tween, one type of non-ionic surfactants, was used as inner antistatic agent of polypropylene (PP) and the antistatic performance of PP/Tween sheets were evaluated by surface resistivities (ρs) and water contact angles. The influence factors including hydrophile-lipophile balance (HLB) of Tween, addition amount, process conditions and atmospheric humidity were investigated in detail and the results showed Tween 40 with HLB at 15.7 provided PP an optimum antistatic effect with surface resistivity of 1010 Ω/sq, water contact angle of 57°, and surface energy of 49.5 mN/m. The ρs of PP/Tween sheets declined approximately 1 order of magnitude with 10% increasing of relative humidity. In order to improve the washing endurance of antistatic PP, a combination of T40 and cationic PP (CPP) were blended with PP and PP/CPP/T40 sheets revealed improved washing durability, with ρs below 1011 Ω/sq after ultrasound washing. In addition, T40 with double bonds was synthesized and UV crosslinking of modified T40 on PP surface also presented definite effects on water resistance.

  7. Functional behaviour of polypropylene/ZnO-soluble starch nanocomposites

    International Nuclear Information System (INIS)

    ZnO-polypropylene nanocomposites (nano-PP) were prepared using nanoparticles of ZnO stabilized by soluble starch (nano-ZnO) as filler in PP by the melt mixing process. X-ray diffraction (XRD) and other spectroscopic analysis-ultraviolet-visible (UV-vis), Fourier transform infrared (FTIR) and photoluminescence-revealed the presence and characteristics of nano-ZnO in the composites. The presence of ZnO imparts whiteness, while starch increased the yellowing of polymers. The nanocomposites were analyzed for changes in optical, mechanical, electrical and rheological properties, as influenced by the increasing concentration of nano-ZnO. The mechanical properties were marginally increased and the dielectric strength of the nano-PP increased to a notable level. By monitoring the evolution of the carbonyl absorption bands from FTIR analysis, the efficacy of nano-ZnO in the reduction of photo-degradation due to UV irradiation was demonstrated. The excellent antibacterial activity exhibited by nano-ZnO impregnated PP against two human pathogenic bacteria, Staphylococcus aureus and Klebsiella pneumoniae, makes it a suitable candidate for food packaging applications

  8. Radiation Effects on Polypropylene Carbon Nanofibers Composites: Spectroscopic Investigations

    Science.gov (United States)

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

    2010-03-01

    Dispersion of carbon nanostructures within polymeric matrices affects their physical and chemical properties (increased Young modulus, improved thermal stability, faster crystallization rates, higher equilibrium degree of crystallinity, modified glass, melting, and crystallization temperatures, enhanced thermal and electrical conductivity). Nevertheless, little is known about the radiation stability of such nanocomposites. The research is focused on spectroscopic investigations of radiation-induced modifications in isotactic polypropylene (iPP)-vapor grown nanofiber (VGCNF) composites. VGCNF were dispersed within iPP by extrusion at 180^oC. Composites containing various amounts of VGCNFs ranging from 0 to 20 % wt. were prepared and subjected to gamma irradiation, at room temperature, at various integral doses (10 MGy, 20 MGy, and 30 MGy). Raman spectroscopy, ATR, and WAXS were used to assess the radiation-induced modifications in these nanocomposites. Acknowledgements: This research was supported by the Welch Foundation (Department of Chemistry at UTPA), by Air Force Research Laboratory (FA8650-07-2-5061) and by US Army Research Laboratory/Office (W911NF-08-1-0353).

  9. Mechanical properties of graphene nanosheets/polypropylene composites

    Science.gov (United States)

    Hsu, P.; Chen, S.; Tsai, I.

    2015-03-01

    In this study, the effect of the various solid contents of graphene nanosheets (GNSs) on the mechanical properties (tensile, flexural and impact strength) of nanosheets and polypropylene (PP) composites formed by injection molding was determined. The material was used with graphene microencapsulated PP pellets. The experimental results indicated that the GNS/PP composites had a maximal tensile strength of 29.54 MPa when the solid GNS content was 0.2 wt%, which increased 8.24 % compared with that of the neat PP matrix. The flexural strength of the GNS/PP composites achieved a maximal value of 25.47 MPa when the solid GNS content was 0.4 wt%, which increased % compared with that of the neat PP matrix. In determining the impact energy, the GNS/PP composites exhibited a maximal value of 861.39 J/m when the solid GNS content was 0.2 wt%, which increased 33.95 % compared with that of the neat PP matrix.

  10. Influence of chemical treatment of clay to obtain polypropylene nanocomposites

    International Nuclear Information System (INIS)

    Commercial clay was chemically treated to prepare a Ziegler-Natta catalyst containing MgCl2 and clay for the synthesis of polypropylene nanocomposites by in situ polymerization. The performance of this catalyst and materials obtained in propylene polymerization was compared with a reference catalyst (without clay) and with another, whose composition presents the same clay but without prior chemical treatment. Techniques like differential scanning calorimetry (DSC), X-ray diffractometry (XRD) and melt flow index (MFI) measurements were performed. There was a marked reduction in catalytic activity of clay catalysts in comparison with the reference one, and a slight reduction in melting temperature of the polymers produced from first ones. The melt flow index of polymers obtained with treated clay were notably higher than those synthesized with the untreated clay, so the treated clay caused treated the production of PP's with lower molar mass. The clays showed an increase of spacing and irregular stacking of the lamellas, especially if chemically treated. (author)

  11. The nonlinear time-dependent response of isotactic polypropylene

    CERN Document Server

    Drozdov, A D

    2002-01-01

    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 active meso-domains (where junctions slip with respect to their positions in the bulk medium with various rates). The distribution of activation energies for sliding in active meso-regions is described by a random energy model. Adjustable parameters in the stress--strain relations are found by fitting experimental data. It is demonstrated that the concentration of active meso-domains monotonically grows with strain, whereas the average potential energy for sliding of junctions and the standard deviation of activation energies suffer substa...

  12. Microscopic, physical and mechanical analysis of polypropylene fiber reinforced concrete

    International Nuclear Information System (INIS)

    This investigation examined the reinforcing effects and mechanisms of polypropylene fiber (PF) on the physical and mechanical properties of concrete. Scanning electron microscope (SEM) was used to observe the crystal structures and that at the aggregate-cement interfacial transition zone. Physical and mechanical tests were performed to measure the effects of PF on improving concrete's engineering properties. Results indicate that PF significantly alters the microstructure of concrete, reduces the crystallization and orientation of Ca(OH)2, and decreases micro-voids. Specifically, PF forms a network that restricts the growth of Ca(OH)2, bridges cracking, and reallocates stresses. PF has reduced the amount and size of crystalline, and the micro-cracking at the aggregate-cement interfacial transition zone. As a result, PF has effectively improved concrete's compressive strength, flexural strength, bonding strength, dynamic performance, and fatigue life, while reduced the water penetration and abrasion mass loss. Results also indicate that a PF content of 0.9 kg/m3 has the optimum concrete performance output for the materials used in this study.

  13. [Investigation of nascent polypropylene in-reactor alloy particles].

    Science.gov (United States)

    Luo, Hua-Lin; Zhang, Chun-Bo; Niu, Hui; Zhao, Ying; Dong, Jin-Yong; Wu, Jin-Guang; Wang, Du-Jin

    2013-02-01

    Heterogeneous nascent particles were observed in a pilot product of polypropylene in-reactor alloy, which was polymerized by Ziegler-Natta/Metallocene hybrid catalyst using Spheripol technology. Most of the particles in the product are translucent, and opaque particles were observed as well. The differences in morphology, composition, chain structure, thermal properties and mechanical properties between these two kinds of particles were investigated by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), polarized optical microscopy (POM), and differential scanning calorimetry (DSC) techniques. The results of FTIR, NMR and SEM indicate that different morphology of these two different particles is caused by different content of ethylene-propylene copolymers. The results of DSC and POM showed that the translucent particles has higher crystallization rate than opaque particles due to the presence of ethylene-propylene copolymers. The mechanical properties results showed that the impact resistance property of opaque particles is obviously lower than that of translucent particles, while its tensile strength and bending modulus are much higher than that of translucent particles. Based on the process of Spheripol technology, a preliminary explanation for the formation of different nascent PP in-reactor alloy particles is proposed. PMID:23697124

  14. Bacterial growth on chitosan-coated polypropylene textile.

    Science.gov (United States)

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

    2012-01-01

    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 submerged into a growth medium inoculated with green fluorescein protein labelled Pseudomonas aeruginosa. After overnight incubation at 33°C, the textile was observed using confocal laser scanning microscopy for bacterial enumeration and biofilm structure characterisation. In the second stage, the textile was used as a filter medium for prefiltered river water, and the pressure development on the in-flow side was measured to quantify the overall level of biofouling. In both cases, nontreated textile samples were used as a control. The results indicate that the chitosan coating exhibits antibacterial properties. The developed method is applicable for the evaluation of the ability to inhibit biofilm formation. PMID:23724330

  15. Glass Fiber Reinforced Polypropylene Mechanical Properties Enhancement by Adhesion Improvement

    Directory of Open Access Journals (Sweden)

    Mariana Etcheverry

    2012-06-01

    Full Text Available Glass fibers (GF are the reinforcement agent most used in polypropylene (PP based composites, as they have good balance between properties and costs. However, their final properties are mainly determined by the strength and stability of the polymer-fiber interphase. Fibers do not act as an effective reinforcing material when the adhesion is weak. Also, the adhesion between phases can be easily degraded in aggressive environmental conditions such as high temperatures and/or elevated moisture, and by the stress fields to which the material may be exposed. Many efforts have been done to improve polymer-glass fiber adhesion by compatibility enhancement. The most used techniques include modifications in glass surface, polymer matrix and/or both. However, the results obtained do not show a good costs/properties improvement relationship. The aim of this work is to perform an accurate analysis regarding methods for GF/PP adhesion improvement and to propose a new route based on PP in-situ polymerization onto fibers. This route involves the modification of fibers with an aluminum alkyl and hydroxy-α-olefin and from there to enable the growth of the PP chains using direct metallocenic copolymerization. The adhesion improvements were further proved by fragmentation test, as well as by mechanical properties measurements. The strength and toughness increases three times and the interfacial strength duplicates in PP/GF composites prepared with in-situ polymerized fibers.

  16. Comparison of the effects of two different types of suture material and two different suturing techniques on late postoperative stenosis in rabbit trachea

    Directory of Open Access Journals (Sweden)

    Mehmet BİLGİN

    2002-12-01

    Full Text Available Purpose: The authors aimed at determining the most suitable surgical technique and suture material in order to increase the quality of life and to decrease the surgical granulation tissue that impairs pulmonary functions by postoperative tracheal stenosis .Material and Method: This experimental study was carried out on 24 New Zeland rabbits of both sexes. Effects of two different suture materials and two different surgical techniques on late recovery period were compared in the developing rabbit trachea .Results: Average tracheal area were calculated as 19.69±2.18 mm2 in the 1st group, 15.33±2.69 mm2 in the 2nd group, 16.95±2.93 mm2 in the 3rd group and 9.01±2.64 mm2 in the 4th group. A statistically significant difference was found (p<0.05. The proportion of the tracheal area measured at control surgery to the optimal tracheal area was found as follows: 0.78 in the 1st group, 0.61 in the 2nd group, 0.69 in the 3rd group, and 0.35 in the 4th group. A statistically significant difference was found between the groups with respect to tracheal area proportions (p<0.05.Conclusion: Our results suggest that absorbable sutures that are stitched intermittently are superior to other methods or materials for the tracheobronchial reconstruction operations carried out in the childhood period.

  17. INCIDENCE OF SUTURAL BONES WITH SPECIAL REFERENCE TO SEX - A STUDY IN THE EASTERN REGION OF INDIA

    Directory of Open Access Journals (Sweden)

    Anirban

    2013-11-01

    Full Text Available ABSTRACT: Context (Background: Many authors have studied sutural bones in various parts of the world. Examples of such work done in the Eastern Region of I ndia are not known to many in the medical community. Therefore, the authors have endeavored to give some insight into the topic and compile a baseline data of such traits by studying the incidence and distribution of various types of sutural bones in the E astern region of India. AIMS : To study the incidence and distribution of various types of sutural bones in the Eastern region of India with particular attention to sex distribution. SETTINGS AND DESIGN : A cross - sectional observational study was conducted b ased on dry adult crania in the muse um of Department of Anatomy over a period of 1 year. METHODS AND MATERIAL: 111 dry adult crania were selected as per inclusion and exclusion criteria. The number of crania with sutural bones in each sex, the total number of sutural bones in each sex and the distribution of sutural bones present bilaterally and in the midline in both males and females were studied. STATISTICAL ANALYSIS : Z - Test was performed for the distribution of sutural bones. A p - value <0.05 was consid ered significant. The results were calculated using Epi Info TM statistical software (version 3.4.1 July 3, 2007 for Windows. RESULTS : The gross incidence of sutural bones was 69.37%. The gross percentages of males and females with sutural bones were 38.74 and 30.63 respectively. Higher number of sutural bones were observed in females (188 compared to males (153. There was a statistically significant difference in the distribution of LO type of sutural bone present bilaterally between male and female cran ia. CONCLUSION: Minor variations in the ossicles of the cranium have aroused the curiosity of anatomists for many decades. Studies have shown that the presence of sutural bones is associated with other cranial and central nervous system abnormalities. The presence of sutural bones as small islands of bone lying within the lambda should not be confused with fractures of the skull. Thus these are important for radiologists, surgeons and forensic personnel. Further investigation into the cause of differences i n the distribution of sutural bones may lead to the unraveling of developmental events associated with them.

  18. Properties analysis of tensile strength, crystallinity degree and microstructure of polymer composite polypropylene-sand

    International Nuclear Information System (INIS)

    Materials modification base on polymer toward polymer composite is needed by addition of filler. Mechanical properties such as tensile strength, crystallinity degree and microstructure of polymer composite based on polypropylene with sand filler have been investigated. In this work, the polymer composite has been made by mixing the matrix of polypropylene melt flow 2 (PP MF2) or polypropylene melt flow 10 (PP MF 10) with sand filler in a labo plastomill. The composition of sand filler was varied to 10, 30, 40 and 50 % v/v, a then the composite were casted to the film sheets form. The sheets were characterized mechanically i.e tensile strength, crystallinity degree and microstructure. The result showed that the tensile strength decreased by increasing the volume fraction of sand filler, in accordance with microstructure investigation that the matrix area under zone plastic deformation (more cracks), while the filler experienced elastic deformation, so that the strength mechanism of filler did not achieved with expectation (Danusso and Tieghi theory). For filler more than 30 % of volume fraction, the tensile strength of polypropylene melt flow 10 (PP MF 10) was greater than that polypropylene melt flow 2 (PP MF2). It was caused by plasticities in PP MF 10. The tensile strength of PP MF2 was greater than that PP MF 10 for volume fraction of sand filler less than 30 %. It was caused by PP MF2 to be have more degree of crystallinity

  19. Histopathological Comparison of Mosquito Net with Polypropylene Mesh for Hernia Repair: An Experimental Study in Rats.

    Science.gov (United States)

    Sharma, Mukesh; Sharma, Deepti Bala; Chandrakar, Shiv Kumar; Sharma, Dhananjaya

    2015-12-01

    Use of mosquito net, in place of polypropylene mesh, had been reported for tension-free hernia repair, as a better cost-effective option. This experimental histopathological study was performed in rats to find out the tissue response and the foreign body reaction and its comparison between commercial polypropylene mesh and the sterilized mosquito net. This experimental study was conducted in the Department of Surgery, Government NSCB, Medical College, Jabalpur (Madhya Pradesh), India. It was carried out in 40 albino rats. A 1.5??0.5-cm hernial defect was created by excising full-thickness abdominal wall muscle. All rats underwent on-lay mesh repair of hernial defect (polypropylene mesh, n?=?20; mosquito net, n?=?20). Half of rats in each group were sacrificed on day 14, and the other half, on day 90. Sections of containing mesh were examined histopathologically for inflammatory infiltrate, giant cells, and collagen deposition. Mosquito net group showed significantly greater number of giant cells and inflammatory cells at 14 and 90days (p??0.05 and p?>?0.05, respectively). Results of mosquito net are comparable to conventional polypropylene mesh. In a setup, where cost-effectiveness is of primary importance, use of mosquito net for tension-free hernia repair can be an acceptable alternative as proven histologically, to commercially available polypropylene mesh. PMID:26730055

  20. Characterization of calcium carbonate obtained from oyster and mussel shells and incorporation in polypropylene

    Directory of Open Access Journals (Sweden)

    Michele Regina Rosa Hamester

    2012-04-01

    Full Text Available There is a high content of calcium carbonate in mussel and oyster shells, which can be used in the formulation of medicine, in construction or as filler in polymer materials. This work has as its main objective to obtain calcium carbonate from mussel and oyster shells and used as filler in polypropylene compared their properties with polypropylene and commercial calcium carbonate composites. The shellfish was milling and heated at 500 ºC for 2 hours. The powder obtained from shellfish were characterized by scanning electron microscopy (SEM, X-ray fluorescence, particle size distribution and abrasiveness and compared with commercial CaCO3 and mixed with polypropylene. The thermal and mechanical properties of polypropylene with CaCO3 obtained from oyster and mussel shells and with commercial CaCO3 were analysed. The results showed that CaCO3­ can be obtained from oyster and mussel shell and is technically possible to replace the commercial CaCO3 for that obtained from the shells of shellfish in polypropylene composites.

  1. Constitutive modeling of the viscoelastic and viscoplastic responses of metallocene catalyzed polypropylene

    DEFF Research Database (Denmark)

    Drozdov, Aleksey; Christiansen, Jesper de Claville; Sanporean, Catalina-Gabriela

    2012-01-01

    Purpose – The purpose of this paper is to perform experimental investigation and constitutive modeling of the viscoelastic and viscoplastic behavior of metallocene catalyzed polypropylene (mPP) with application to lifetime assessment under conditions of creep rupture. Design/methodology/approach ......Purpose – The purpose of this paper is to perform experimental investigation and constitutive modeling of the viscoelastic and viscoplastic behavior of metallocene catalyzed polypropylene (mPP) with application to lifetime assessment under conditions of creep rupture. Design...... arbitrary three-dimensional deformation with small strains, and its parameters are found fitting the observations. Findings – Crystalline structure and molecular architecture of polypropylene strongly affect its time and rate-dependent behavior. In particular, time-to-failure of metallocene catalyzed...... polypropylene under tensile creep noticeably exceeds that of isotactic polypropylene produced by the conventional Ziegler-Natta catalysis. Originality/value – Novel stress-strain relations are developed in viscoelastoplasticity of semi-crystalline polymers and applied to predict their mechanical behavior in...

  2. Role of carbon nanotubes (CNTs) in improving wear properties of polypropylene (PP) in dry sliding condition

    International Nuclear Information System (INIS)

    Highlights: ► Role of carbon nanotubes (CNTs) on wear behaviour of polypropylene (PP) is evaluated. ► Effect of applied pressure and composition against a steel counter face is investigated. ► Microstructure and worn surfaces of samples are observed by scanning electron microscope. ► The wear phenomenon has been discussed based on wear losses and worn surfaces. ► The coefficient of friction (μ) and sliding time for PP and PP/CNT blend is investigated. - Abstract: Polymers are widely used for sliding couples against metals and other materials. Polypropylene is a polymer used in variety of applications includes packaging, laboratory equipments, automotive components, etc. Polypropylene is often desirable automotive material due to its low cost, colorability, chemical resistance and UV stability. In addition the range of potential polypropylene uses is nearly unlimited through the use of modifiers, additives and fillers. In the present work, the sliding wear of polypropylene (PP) and carbon nanotube (CNT) blends are evaluated as a function of applied load and composition against a steel counter face in dry condition. The addition of CNT in PP in wear performance is investigated and presented in detail. Microstructure and worn surfaces of samples were observed by scanning electron microscope. The wear phenomenon has been discussed based on wear losses and worn surfaces

  3. Radiation-modified blends of the basis of polyethylene terephthalate and polypropylene

    International Nuclear Information System (INIS)

    The binary composite systems on the basis of post-consumer poly-(ethylene terephthalate) and polypropylene have been investigated. Mechanical properties of the compositions were studied in detail in order to expand the application possibilities of tested binary composites. Structural changes of the poly (ethylene terephthalate) / polypropylene blends depending on the concentration of the components were investigated also. Additionally, the optimum processing conditions were established. Particular attention was paid to study the influence of the ionizing γ-radiation on the structural and mechanical properties of the composition systems tested. The magnitude of the adsorbed dose od γ-radiation was established to affect differently the structure of poly(ethylene terephalate) and polypropylene. At small absorbed doses (50 kGy) crosslinking of the polymer was observed for both poly(ethylene terephthalate) and polypropylene resulting in the increase of some mechanical properties of pure materials as well of their compositions, whereas the absorbed dose of 300 kGy caused the destruction of the tested materials. It is important to mention that the rate of radiation-chemical destruction of polypropylene is higher than poly(ethylene terephthalate) destruction rate. (author)

  4. Comparative study of polypropylene and aponeurotic slings in the treatment of female urinary incontinence

    Directory of Open Access Journals (Sweden)

    Jorge A. Winckler

    2010-06-01

    Full Text Available PURPOSE: Female stress urinary incontinence (SUI, the involuntary leakage of urine, is a highly prevalent social and hygiene problem, and various surgical techniques have been developed to correct it. This study used the technique of an aponeurosis sling made from the rectus abdominis muscle as a standard and compared the technique to a sling made with a polypropylene mesh, (Marlex. MATERIALS AND METHODS: From 2000 to 2007, 158 women who underwent surgery for SUI with an aponeurosis sling, (average age 55 years, were used as a standard for comparison with 316 women who underwent surgery with a polypropylene sling (average age 55 years. RESULTS: The mean follow-up period was 3.65 and 3.56 years for the respective groups. The aponeurosis group showed a cure of SUI in 128 (81.0%, improvement in 23 (14.6%, and failure in 7 (4.4%. The polypropylene group showed a cure in 281 (88.9%, improvement in 23 (7.3%, and failure in 10 (3.2% (p = 0.083. Urgency was observed in 19 (12% of the aponeurosis group, and 28 (8.9% in the polypropylene group (p = 0.320. CONCLUSIONS: This study showed that the polypropylene mesh is an effective alternative to construct a sling for SUI in women. The results and rates of complication were comparable to the fascial sling from the rectus abdominis muscle aponeurosis.

  5. A study of low temperature mechanical properties and creep behaviour of polypropylene using a new sub-ambient temperature nanoindentation test platform

    International Nuclear Information System (INIS)

    Mechanical properties and creep behaviour of an atactic-polypropylene (aPP) have been studied in the vicinity of its glass transition temperature (-18 0C) via a nanoindentation platform integrated with a sub-ambient temperature capability. All low temperature tests were validated by measurements on a fused silica reference sample from 25 to -30 0C. The fused silica results showed virtually invariant elastic modulus with temperature over this range consistent with the literature measurements by sonic resonance. Hardness and elastic modulus of aPP increased as the test temperature decreased and the amorphous regions went through the glass transition. The creep behaviour was analysed using two approaches: (i) a logarithmic method and (ii) the Boltzmann integral method. The results showed that the creep extent decreased as the temperature was reduced, and for the time constants obtained there were upper-limit values at -10 0C, about 8 0C above the quoted glass transition temperature. The strain rate sensitivity obtained by the logarithmic method also showed a maximum at -10 0C.

  6. Platelet-Rich Plasma Alone Is Not Sufficient to Enhance Suture Repair of the ACL in Skeletally Immature Animals: An In Vivo Study

    OpenAIRE

    MURRAY, MARTHA M.; Palmer, Matthew; Abreu, Eduardo; Spindler, Kurt P.; Zurakowski, David; Fleming, Braden C

    2009-01-01

    In this study, we hypothesize that supplementation of suture repair of the anterior cruciate ligament (ACL) with platelet-rich plasma (PRP) will improve the biomechanics of the repair. Six 30-kg pigs underwent bilateral suture repair of the ACL. One side was treated with suture repair alone, while the contralateral side was treated with suture repair augmented with PRP. After 14 weeks in vivo, anteriorposterior (AP) knee laxity and the tensile properties of the repaired ligament were measure...

  7. New suture techniques for best esthetic skin healing Novas técnicas de suturas para melhor cicatrização estética da pele

    OpenAIRE

    Otoni Moreira Gomes; André Silva Campos do Amaral; Ariel José Villar Gonçalves; Auro Sérgio Perdigão de Brito; Ernesto Lentz de Carvalho Monteiro

    2012-01-01

    PURPOSE: To report two new suture techniques for best esthetic skin healing. METHODS: Using the pig skin slices routinely employed for surgical technique training two new types of skin sutures were performed. One defined as inverted or hidden X point suture and other as totally hidden intradermal running suture. The first were performed using 4-0 polypropilene stitch and the intradermal with 4-0 poliglicolic stitch. RESULTS: It was confirmed good skin layers union and contention with best est...

  8. 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

    Directory of Open Access Journals (Sweden)

    José Guilherme Minossi

    2010-10-01

    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" .

  9. Compton telescope of high angular resolution to measure gamma rays between 0,3 and 10,0 MeV

    International Nuclear Information System (INIS)

    An experimental device to measure gamma-rays of energy between 0,3 and 10,0 MeV, on-board of a stratospheric baloon, is described. The data obtained in the laboratory, using monoenergetic radioactive sources of gamma-rays, allow of the determination of the directivity of this compton telescope

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

    Directory of Open Access Journals (Sweden)

    Lippert, Hans

    2006-08-01

    Full Text Available 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 problems in terms of degradability. The use of surgical suturing material coated with triclosan is seen especially in contaminated wounds or where the risk of infection is high. In order to meet this requirement, the antimicrobial properties of triclosan are particularly emphasized.Both in vitro and in vivo, triclosan is highly effective against Staphylococcus spp., including MRSA, the pathogens most frequently involved in postoperative wound infections. Triclosan is not effective against Pseudomonas aeruginosa, Serratia marcescens and Alcaligenes spp., due to their intrinsic resistance against this agent.As long as the inducible resistance in vitro against triclosan is not clinically relevant, it does not speak against triclosan use in suturing material, especially because pure triclosan is applied only to a specific, limited area for a short time. However, because triclosan can induce in vitro the development of cross-resistances to antibiotics, the implementation of this agent must be exclusively limited to medically founded indications.

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

    Directory of Open Access Journals (Sweden)

    William F Masih

    2014-02-01

    Conclusion: The fusion of endocranial vault sutures occurred 5-10 years earlier as compared to ectocranium and it is more reliable. The obliteration sets little early and proceeds more slowly in the females than in males. [Natl J Med Res 2014; 4(1.000: 19-22

  12. Adjustment of gamma radiation doses for sterilization of Egyptian surgical sutures

    International Nuclear Information System (INIS)

    The adjustment of gamma radiation doses for sterilization of catguts under local manufacturing conditions has been performed. Average total initial counts for aerobic and anaerobic bacteria per item were relatively low, in the range of 1000 counts for aerobic and 10 counts for anaerobic bacteria. The microfiora (aerobic bacteria) of the studied sutures were isolated and identified to be: Bacillus sp.; Micrococcus varians, Micrococcus roseus, and Staphylococcus. Each purified and identified isolate was exposed to gamma radiation both in liquid media (broth) and in the preservative in which the sutures were supplied by the company. The LD values of the most resistant microorganisms in both case of liquid media and preservative, were obtained to be around 5 KGy. Deliberately contaminated sterile sutures with each isolate and with mixture of isolates were studied. The sterilizing dose was obtained to be 20KGy for most heavily contaminated items (1010 counts) irradiated both in saline and in preservative. This sterilizing dose was found to be dependent of the initial viable counts. This value was considered to be a safe value for radiosterilization of the studied sutures preserved in isopropyl alcohol, glycerin, and water (90:3.5:16)

  13. Virtual suturing simulation based on commodity physics engine for medical learning.

    Science.gov (United States)

    Choi, Kup-Sze; Chan, Sze-Ho; Pang, Wai-Man

    2012-06-01

    Development of virtual-reality medical applications is usually a complicated and labour intensive task. This paper explores the feasibility of using commodity physics engine to develop a suturing simulator prototype for manual skills training in the fields of nursing and medicine, so as to enjoy the benefits of rapid development and hardware-accelerated computation. In the prototype, spring-connected boxes of finite dimension are used to simulate soft tissues, whereas needle and thread are modelled with chained segments. Spherical joints are used to simulate suture's flexibility and to facilitate thread cutting. An algorithm is developed to simulate needle insertion and thread advancement through the tissue. Two-handed manipulations and force feedback are enabled with two haptic devices. Experiments on the closure of a wound show that the prototype is able to simulate suturing procedures at interactive rates. The simulator is also used to study a curvature-adaptive suture modelling technique. Issues and limitations of the proposed approach and future development are discussed. PMID:21165761

  14. 21 CFR 878.4494 - Absorbable poly(hydroxybutyrate) surgical suture produced by recombinant DNA technology.

    Science.gov (United States)

    2010-04-01

    ... produced by recombinant DNA technology. 878.4494 Section 878.4494 Food and Drugs FOOD AND DRUG... recombinant DNA technology. (a) Identification. An absorbable poly(hydroxybutyrate) surgical suture is an... deoxyribonucleic acid (DNA) technology. The device is intended for use in general soft tissue approximation...

  15. The nature and location of the suture zone in the Rokelide orogen, Sierra Leone: Geochemical evidence

    Science.gov (United States)

    Lytwyn, Jennifer; Burke, Kevin; Culver, Stephen

    2006-12-01

    The boundaries of the West African Craton mark the location of a continuous suture zone that records Neoproterozoic to Early Cambrian oceanic closure. The western part of the circum-West African suture zone extends through the line of outcrop of the Mauritanide, Bassaride and Rokelide mountain belts. Our geochemical analyses are consistent with the idea that igneous and metamorphic rocks of the Rokelide and Southern Mauritanide mountain belts of West Africa occupy a suture zone that records the closing of a Neoproterozoic to Early Cambrian ocean basin during the Pan-African orogeny and final assembly of Gondwana. The closing of that basin was marked by the collision between Archean rocks of the Leo massif of the West African Craton and reactivated Archean and Paleoproterozoic rocks that now outcrop nearer to the coast of Africa in Sierra Leone and Liberia. Within the Rokelides, the geochemistry of the Kasewe Hills volcanic rocks and Marampa amphibolite indicate that remnants of an arc system are caught up in the suture zone. The geochemistry of Guingan schists that outcrop along strike of the Rokelides is compatible with the idea that the metamorphosed equivalents of the Marampa and Kasewe Hills arc volcanic rocks extend through the Bassarides and into the Southern Mauritanides.

  16. A Technique to Make Multiple Proximal Anastomoses with One HEARTSTRING Suture Device.

    Science.gov (United States)

    Tokunaga, Shigehiko; Tominaga, Norihisa; Lee, SangHun; Masuda, Munetaka

    2016-04-01

    The HEARTSTRING device allows a secure proximal anastomosis, but one device is typically used for each anastomosis. We report a technique to make multiple proximal anastomoses with one HEARTSTRING suture device. doi: 10.1111/jocs.12706 (J Card Surg 2016;31:206-207). PMID:26857221

  17. Operative treatment of acromioclavicular joint dislocation: a new technique with suture anchors

    Directory of Open Access Journals (Sweden)

    Zhang Jingwei

    2014-07-01

    Full Text Available 【Abstract】Objective: To evaluate clinical outcome of suture anchors in strengthening both acromioclavicular and coracoclavicular ligaments in the surgical treatment of acromioclavicular joint dislocation. Methods: Twenty-eight patients with acute traumatic Rockwood III, IV and V dislocations of the acromioclavicular joint surgically treated at our institute between October 2010 and January 2012 were recruited. All patients underwent open reduction combined with suture anchors. Function was evaluated using the ConstantMurley shoulder score. Clinical and radiographic shoulder ratings were evaluated using Taft criteria at 3, 6 and 12 months. Results:Two cases with fixation loosening were not included in final statistical analysis. Other patients obtained full joint reposition on immediate postoperative radiographs. Follow-up was performed with an average of 15.6 months (range, 12-19. After early range of motion exercises, 96.2% of the patients (25/26 could abduct and elevate their shoulders more than 90 degrees within postoperative 3 months. There was no infection. Average Constant-Murley score was 96.3 points (range, 94-100 and mean Taft shoulder rating was 10.7 points (range, 8-12 at 12 months. Conclusion: The suture anchor is a relatively simple technique and can avoid screw removal which is helpful in reconstructing both acromioclavicular and coracoclavicular ligaments in acute traumatic acromioclavicular joint dislocation. Key words: Acromioclavicular joint; Dislocations; Surgery; Suture anchors

  18. Operative treatment of flexor pollicis longus tendon with Krackow suture, functional results: Preliminary results

    Directory of Open Access Journals (Sweden)

    Bumbairevi? Marko .

    2010-01-01

    Full Text Available INTRODUCTION: Surgical treatment of the injuried flexor tensons is the important part of hand surgery. Tendon adhesions, ruptures, joint contcatures-stifness are only one part of the problem one is faced during the tendon treatment. In spite of improvement in surgical technique and suture material, the end result of sutured flexor tendons still represent a serious problem. THE AIM of study is to present of operative treatment of flexor pollicis longus injury with Krakow suture technique. METHODS. All patients are treated in the first 48 hours after the accident. The regional anesthesia was performed with use of turniquet. Beside spare debridement, the reconstruction of digital nerves was done. All patients started with active and pasive movements-excercises on the first postoperative day. Follow-up was from 6 to 24 months. In evaluation of functional recovery the grip strenght, pinch strenght, range of movements of interphalangeal and metacarpophalangeal joint and DASH score were used. RESULTS. In the last two years there were 30 patients, 25 males (83.33% and 5 females (16.66%. Mean age was 39.8 years, ranged from 17 to 65 years. According to mechanism of injury the patients were divided in two groups: one with sharp and other with wider zone of injury. Concomitant digital nerve lesions was noticed in 15 patients (50%. CONCLUSION. The Krackow suture allowed early rehabilitation, which prevent tendon adhesions, enabled faster and better functional recovery.

  19. Randomised controlled study of two different techniques of skin suture in endoscopic release of carpal tunnel

    DEFF Research Database (Denmark)

    Hansen, Torben Bk; Kirkeby, Lone; Fisker, Heidi; Larsen, Kristian

    2009-01-01

    In a prospective, randomised trial of 54 hands in 47 patients incisions were randomised to be closed by either absorbable subcuticular (polyglytone 6211, Caprosyn), or non-absorbable interrupted (polybutester, Novafil), sutures after single-portal endoscopic release of the carpal tunnel. There was...

  20. Athermal Tension Adjustable Suture Ligation of the Vascular Pedicle During Robot-Assisted Prostatectomy*

    Science.gov (United States)

    Beck, Shawn M.; Skarecky, Douglas; Miller, Scott

    2012-01-01

    Abstract Purpose We report a simple figure-of-eight tension adjustable suture to ligate the vascular pedicle (VP) during robot-assisted radical prostatectomy (RARP). Materials and Methods During nerve-sparing RARP, after the rectum has been mobilized, the VP is isolated and prepared for transection. Previous reports describe placing of hemostatic clips (metallic or Hem-o-lok) or laparoscopic bulldog clamps (30?mm) to control and oversew the VP; both techniques are quite assistant dependent. We present a bulldog clamp alternative by placing a figure-of-eight fashion, a 6-cm 3-0 poliglecaprone on an SH needle with a small loop tied in the suture end. After the needle has been placed through the VP, it is then threaded through the preformed loop and then a small Hem-o-lok clip is placed and cinched down to occlude the blood vessels. Next, the VPs are transected. The clip can be further cinched, mimicking the technique used in partial nephrectomy, to control bleeding when encountered. Data were collected prospectively to demonstrate safety. Results We report on 74 men totaling 143 VPs using this new technique. The average operative time was reduced by 15 minutes compared with using bulldog clamps. In the initial 10 cases (20 attempts), inadvertent transection of the suture occurred three times. In these three cases, hemostasis was (easily) controlled with additional sutures. Conclusions The pedicle stitch technique offers an assistant independent alternative for a simple and precise athermal means to control the VP. PMID:22191496