WorldWideScience

Sample records for 10-0 polypropylene suture

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

    International Nuclear Information System (INIS)

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

  2. 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.

  3. 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)

  4. Comparison of adhesive polyurethane membrane and polypropylene sutures for closure of skin incisions in cats.

    Science.gov (United States)

    Court, M H; Bellenger, C R

    1989-01-01

    Paired skin incisions were made on each side of four cats and closed with either interrupted polypropylene sutures or adhesive polyurethane membrane. The healing of these wounds was compared by gross appearance, break strength determination, and histologic examination. The adhesive polyurethane membranes were quicker and easier to apply, producing a more uniform closure than sutures both clinically and histologically. They adhered strongly to the skin, supporting more wound length than sutures for the first 7 days. There were no differences in break strength between closure techniques. Histologically, the wounds closed with adhesive polyurethane membrane were characterized by a milder inflammatory reaction and greater vascular infiltration than sutured wounds, especially early in the healing period. PMID:2773283

  5. 21 CFR 878.5010 - Nonabsorbable polypropylene surgical suture.

    Science.gov (United States)

    2010-04-01

    ... SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.5010... controls). The special control for this device is FDA's “Class II Special Controls Guidance Document: Surgical Sutures; Guidance for Industry and FDA.” See § 878.1(e) for the availability of this...

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

    OpenAIRE

    J. F Akinrinmade; A.O. Lawal

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    J. F Akinrinmade

    2010-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Pankaj Shivhare

    2014-06-01

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

  9. 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.

  10. Polypropylene; Polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2004-12-01

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

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

    Scientific Electronic Library Online (English)

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

    2003-10-01

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

  12. 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)

  13. Cranial sutures

    Science.gov (United States)

    ... sutures and fontanelles, the child's brain could not grow enough. The child would develop brain damage. Feeling the cranial sutures and fontanelles is one way that doctors and nurses follow the child's growth and development. They are ...

  14. Deterioration of polypropylene by radiation

    International Nuclear Information System (INIS)

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

  15. Should nylon corneal sutures be routinely removed?

    OpenAIRE

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

    1991-01-01

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

  16. 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

  17. Transscleral suture fixation following recurrent toric intraocular lens rotation.

    Science.gov (United States)

    Arjmand, Parnian; Chan, Toby Y B; Ahmed, Iqbal Ike K

    2015-05-01

    We describe a surgical technique of transscleral suture fixation for recurrent rotation of a double-loop hydrophilic acrylic toric intraocular lens (IOL) in the capsular bag. Two 9-0 polypropylene sutures are placed in the proximal and distal angulations of 1 of the IOL haptics through the capsular bag. The clockwise and counterclockwise traction provided by these sutures prevents rotation of the IOL in either direction. This technique can be used in cases of spontaneous postoperative IOL rotation to achieve stabilization. In the case we describe, the IOL remained stable 11 months following transscleral suture fixation at the desired axis. PMID:25956713

  18. Electron beam sterilization surgical sutures, 2

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  20. Use of Absorbable Sutures in Canine Carotid Arteries

    OpenAIRE

    Rey, Alejandro R.; Carrillo-Farga, Joaquin; Velasco, Carlos O.; Valencia, Martin O.V.

    1990-01-01

    To study the functional and microstructural characteristics of polydioxanone sutures in vascular surgery, we created 48 vascular anastomoses in the right and left common carotid arteries of 24 mongrel dogs. In each animal, polydioxanone sutures were used in 1 carotid artery, and polypropylene sutures were used in the contralateral carotid artery. Twelve groups of 2 animals each were then formed. The 1st group was observed for 1 month, the 2nd for 2 months, the 3rd for 3 months, and so on unti...

  1. [Ideal suture methods for skin, subcutaneous tissues and sternum].

    Science.gov (United States)

    Ogawa, Rei

    2012-04-01

    Non-absorbable sternal closure methods such as stainless steel wiring have been widely used, but biocompatibility and osteoconductivity of absorbable materials have advantages in acceleration of wound healing. Combined use of stainless steel wires with absorbable materials may contribute to minimizing sternal complications.Fascial tension reduction sutures, where the tension is placed on the layer of deep fascia and superficial fascia, are recommended for skin/subcutaneous closure. This means that the use of dermal sutures is minimized;indeed, dermal sutures can be avoided altogether if the wound edges can be joined naturally under very small tension. We prefer 0, 2-0 polydioxanone sutures (PDS II) for deep/superficial fascia sutures, 4-0 or 5-0 PDS II for dermal sutures (if they are necessary), and 6-0 or 7-0 polypropylene or nylon sutures (Proline or Ethilon) for superficial sutures. The consequence of such suturing is that the wound edges are elevated smoothly with minimal tension on the dermis that appears to prevent the development of large scars. PMID:22485038

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

    Directory of Open Access Journals (Sweden)

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

    2008-01-01

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

  3. Radiochemical sterilization and its use for sutures

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Georgios Anthimidis; Marios Gregoriou; Thomas Stavrakis; Kalliopi Vasiliadou; Ioannis Lyras; Kostas Ioannidis; George Basdanis

    2013-01-01

    Background-Aim: The technique of abdominal closure along with the material to be used is constantly evolving. The aim of the present study is to evaluate differences in midline laparotomy closure with a standard closure technique and new-fangled slow-absorbable versus non-absorbable sutures. Material and Methods: A prospective, comparative study of patients undergoing laparotomy closure with either STARDIOX (Polydioxanone) or STARLENE (Polypropylene) sutures during a 9 month period was perfo...

  5. [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

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

    Science.gov (United States)

    Richmond, J C

    2001-01-01

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

  7. [Suture materials in dermatology].

    Science.gov (United States)

    Hundeiker, M

    1988-01-01

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

  8. USE OF POLYPROPYLENE MESH FOR INCISIONAL HERNIA REPAIR

    OpenAIRE

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

    2006-01-01

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

  9. Short- and long-term biomechanical and morphological study of new suture types in abdominal wall closure.

    Science.gov (United States)

    Simón-Allué, R; Pérez-López, P; Sotomayor, S; Peña, E; Pascual, G; Bellón, J M; Calvo, B

    2014-09-01

    To perform an abdominal-wall closure, a continuous suture is the preferred method. The suture materials that are most commonly employed in abdominal surgery are polypropylene and polydioxanone. However, in recent times, new products have been marketed, such as non-absorbable polyurethane with elastic properties (Assuplus(®), Assut Europe, Italy) and absorbable barbed polydioxanone (Filbloc(®), Assut Europe, Italy). The purpose of this study was to compare the ability of those against the standard polypropylene (Surgipro(TM), Covidien, USA) and polydioxanone (Assufil(®), Assut Europe, Italy) to mimic the biomechanical behavior of the abdominal wall closure. Comparison of the sutures was made first with the materials alone and later in a laparotomy closure of a rabbit abdomen, used as an animal model. The biomechanical analysis consisted of uniaxial tensile tests of threads and sutured samples of the animal abdomen. In the latter case, results were analyzed at short- (21days) and long- (180days) term intervals after the surgery. The morphology studies and collagen expression of the samples were also investigated. The results determined that polydioxanone and polypropylene sutures showed a linear elastic behavior, with barbed polydioxanone as the most compliant suture and polyurethane as the stiffest. The sutured samples showed a statistically significant loss of resistance, measured as the load needed to perform a certain stretch, when compared with the corresponding control tissue. Analysis of the stress-stretch curves showed that elastic polyurethane was the only suture able to reproduce the mechanical behavior of healthy tissue in the short term, while the rest of the sutures remained less stiff. This coincides with the expression of type I collagen observed in this group at this point in the study. In the long term, there was no difference among the sutures, and none was able to mimic control behavior. PMID:24859461

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Bansal R

    1992-01-01

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

  12. 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.

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

    Science.gov (United States)

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

    2011-09-01

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

  14. 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

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

    DEFF Research Database (Denmark)

    Hjortdal, Jesper; SØndergaard, Anders

    2011-01-01

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

  16. 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)

  17. Releasable suture technique for trabeculectomy

    Directory of Open Access Journals (Sweden)

    Thomas Ravi

    1997-01-01

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

  18. 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

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

    OpenAIRE

    SIMMS, CIARAN KNUT

    2012-01-01

    Background: 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. Objective: To determine the effect of axial torsional forces on sutures used in abdominal closure. Methods: The effect of axial twisting on polydioxanone (PDS*II...

  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. Unusual sutural bones at pterion

    Directory of Open Access Journals (Sweden)

    Nayak SB

    2008-08-01

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

  3. USE OF POLYPROPYLENE MESH FOR INCISIONAL HERNIA REPAIR

    Directory of Open Access Journals (Sweden)

    Scripcariu V

    2006-07-01

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

  4. 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.

  5. Composite surgical sutures with bioactive glass coating.

    Science.gov (United States)

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

    2003-10-15

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

  6. Argon plasma irradiation of polypropylene.

    Czech Academy of Sciences Publication Activity Database

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

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

  7. Influence of surgical sutures on wound healing

    Directory of Open Access Journals (Sweden)

    Mirkovi? Siniša

    2010-01-01

    Full Text Available Historical data on closing and suturing of surgical wounds describe a wide range of various suture materials. The choice of the surgical catgut, i.e. the type and diameter, depends on the locality, characteristics and condition of the tissue to be treated. From the standpoint of oral-surgical practice the following clinical parameters are of outstanding importance with respect to the selection of suture material: accumulation of soft deposits on the sutures, score of the adjacent soft tissues and dehiscence of the operative wound. Our prospective clinical study included 150 patients distributed into three groups of 50 subjects. The surgical procedure performed on each patient involved resection (apicotomy of the tooth root end in the intercanine sector of the upper jaw. The following suture materials were applied: Black Silc 5-0, Nylon 5-0 and Vicryl 5-0. The effects of the selected sutures were evaluated according to the wound dehiscence. The effects of the applied sutures were recorded on Days 2, 5 and 7 after the surgery. The comparison of cited parameters of the investigated materials after suturing the oral mucosa revealed that none of the used material was ideal; however, a certain advantage might be given to the synthetic monofilament suture materials.

  8. Anastomose arterial com fio de polidioxanona e fio de polipropileno. Estudo comparativo em cães Arterial anastomose with polydioxanone and polypropilene suture. Comparative study in dogs

    Directory of Open Access Journals (Sweden)

    Eloísa de Brida Tormena

    2002-03-01

    Full Text Available Este estudo teve por objetivo comparar os efeitos do fio absorvível de polidioxanona com o fio inabsorvível de polipropileno, em anastomoses término-terminais, em artérias femorais de cães. Foram utilizados 20 cães, separados em dois grupos, para observação no 7º e no 30º dia de pós-operatório. Cada cão teve suas artérias femorais seccionadas e aproximadas em um lado com pontos separados de fio de polidioxanona 6-0, e no lado contralateral com o fio de polipropileno 6-0. A escolha do fio foi feita por sorteio, totalizando 40 anastomoses. Para análise estatística dos resultados aplicaram-se os testes de Fisher, Mac Nemar, Wilcoxon, Mann-Witney e o teste T de Student (a ? 0,05. Nas avaliações clínicas não foram observadas diferenças significantes entre os fios utilizados. Os resultados obtidos nas avaliações arteriográfica e macroscópica dos segmentos arteriais foram semelhantes, assim como na análise histológica morfológica. Na análise histológica morfométrica o fio de polipropileno apresentou número de células gigantes de corpo estranho significativamente maior que o fio de polidioxanona aos 7 e 30 dias de pós-operatório. Os resultados nos permitem concluir que, apesar da maior reação de corpo estranho observada com o fio de polipropileno, o fio de polidioxanona apresentou resultados semelhantes ao fio de polipropileno, em anastomoses arteriais em cães.The objetive of this study was to compare the effects of the absorbable polidioxanone suture to the nonabsorbable polypropylene suture, in end-to-end anastomoses, using dog’s femoral arteries. Twenty dogs were separated in two groups for observation on the 7th and 30th post-operatory day. Each dog had its femoral arteries seccioned and then aproximated one side with separate stitches of polidioxanone 6-0 suture, and the other side with polypropylene 6-0 suture. For the statistical studies Fisher, Mac nemar, Wilsoxon, Mann-Witney and T of Student tests (a ? 0,05 were carried out. No significant differences were observed between the sutures employed in clinical evolution. The results obtained in the arteriographic and macroscopic avaliation were similar, as well as the morphological histologic analysis. In the morfometric histologic analysis the polypropylene suture showed a significantly higher number of foreign body giant cells reaction, comparing to the polydioxanone suture on the 7th or 30th post-operatory day. The results allow us to conclude that, in spit of the higher reaction of foreign body observed with the polypropilene suture, the polydioxanone suture showed similar results in dog’s arterial anastomoses.

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

    Directory of Open Access Journals (Sweden)

    Lee RM

    2012-08-01

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

  10. 21 CFR 878.4495 - Stainless steel suture.

    Science.gov (United States)

    2010-04-01

    ...2010-04-01 2010-04-01 false Stainless steel suture. 878.4495 Section 878.4495...Surgical Devices § 878.4495 Stainless steel suture. (a) Identification. A stainless steel suture is a needled or unneedled...

  11. 21 CFR 878.4830 - Absorbable surgical gut suture.

    Science.gov (United States)

    2010-04-01

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

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

    OpenAIRE

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

    2010-01-01

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

  13. Oxidation induced embrittlement in polypropylene

    OpenAIRE

    Fayolle, Bruno

    2001-01-01

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

  14. Lichtenstein inguinal hernioplasty using butyl-2-cyanoacrylate versus sutures. Preliminary experience of a prospective randomized trial.

    Science.gov (United States)

    Nowobilski, W; Dobosz, M; Wojciechowicz, T; Mionskowska, Lucjanna

    2004-01-01

    The Lichtenstein hernioplasty has become a popular method in inguinal hernia repair. This study compared two methods of mesh fixation and wound closure. Forty-six men with unilateral inguinal hernia were randomized into two groups. In the control group polypropylene mesh was anchored with 3/0 Dexon sutures, fascia and skin were closed with sutures 3/0 Dexon and 3/0 Monosof. In the study group, the mesh was secured with butyl-2-cyanoacrylate adhesive and the fascia and skin were also glued with the adhesive. The costs of materials, duration of the operation, amount of postoperative analgesic doses, pain score after the first and the 7th postoperative day and return to daily activity were recorded. No recurrences during the mean follow-up of 4.7 months were observed and the cosmetic effect was very good. In the study group with tissue adhesive the patients had significantly lower pain score after the first postoperative day and had a tendency to require less analgetic doses and to return earlier to their daily activity. Duration of the operation was similar in both groups. The cost of sutures and tissue adhesive used in both procedures was comparable. The use of tissue adhesive in mesh fixation and wound closure seems to be a promising technique in Lichtenstein hernia repair. PMID:15591746

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2010-12-01

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

  17. 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...

  18. Needle and suture contamination in strabismus surgery

    OpenAIRE

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

    2007-01-01

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

  19. Prolene monofilament suture in Boston Keratoprosthesis surgery

    OpenAIRE

    Kyrillos,, Ralph; Harissi-Dagher, Mona

    2011-01-01

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

  20. Unicoronal suture immobilization in the fetal rabbit.

    Science.gov (United States)

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

    2004-03-01

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

  1. 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. ...

  2. Natural Nanotubes Reinforcing Heterophasic Polypropylene

    Scientific Electronic Library Online (English)

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

    2015-04-01

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

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    Xu-Ting Hu

    2013-12-01

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

  5. Resorbable suture support for ventricular aneurysmectomy.

    Science.gov (United States)

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

    1987-09-01

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

  6. 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.

  7. Laparoscopic fascial suture repair of parastomal hernia.

    Science.gov (United States)

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

  8. Flexor Tenorrhaphy Using Absorbable Suture Materials

    Directory of Open Access Journals (Sweden)

    Hyung Joo Kang

    2012-07-01

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

  9. Polydioxanone suture in the gastrointestinal tract

    OpenAIRE

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

    1987-01-01

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

  10. Le choix d'un matériel de suture

    OpenAIRE

    Olivieri, Michel; Bonneau, Norbert H.

    1985-01-01

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

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

    Science.gov (United States)

    Mitchell, Ryan T M; Bengtson, Bradley P

    2015-10-01

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

  12. 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.

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

    OpenAIRE

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

    2008-01-01

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

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

    Science.gov (United States)

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

    1982-01-01

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

  15. 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)

  16. Electret Stability Related to Spherulites in Polypropylene

    DEFF Research Database (Denmark)

    Thyssen, Anders; Almdal, Kristoffer

    2015-01-01

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

  17. Organobentonite / Polypropylene Nanocomposite for Packaging Application

    Science.gov (United States)

    Varothai, Yukhanthorn; Phandee, Atinuch; Nithitanakul, Manit; Magaraphan, Rathanawan; Manuspiya, Hathaikarn

    2007-03-01

    Na-bentonite was treated with several kind of quaternary alkyl ammonium cation by ion exchange reaction to find the high efficiency one to exfoliate the longer of nanoclay. DOEM exhibited the good performance to continue the work. The organomodified bentonite was compounded with polypropylene by using Surlyn^ ionomer as a compatibilizer to produce the packaging film. In addition the organobentonite was modified by ethylene scavenger chemical and characterized by XRD and FT-IR. It was compound with polypropylene to prepare the active packaging film.The gas permeability, ethylene adsorption-desorption, thermal and mechanical properties were investigated.

  18. Production and properties of polypropylene track membranes

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-10-15

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

  20. SKIN STAPLED OR SUTURED: A COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    Veerendra Kumar

    2015-01-01

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

  1. 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

  2. Polypropylene/aspen/liquid polybutadienes composites.

    Czech Academy of Sciences Publication Activity Database

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

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

  3. Nucleation of polypropylene crystallization by gold nanoparticles.

    Czech Academy of Sciences Publication Activity Database

    Bhardwaj, Monika; Pavlova, Ewa; Šlouf, Miroslav; Sikora, Antonín; Baldrian, Josef

    Praha : Ústav makromolekulární chemie AV ?R, 2010. L_2. ISBN 978-80-85009-62-0. [Workshop "Career in Polymers" /2./. 23.07.2010-24.07.2010, Praha] Institutional research plan: CEZ:AV0Z40500505 Keywords : nucleation * gold nanoparticles * polypropylene crystallization Subject RIV: CD - Macromolecular Chemistry

  4. 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...

  5. Microporous polypropylene-polyamide blend membranes.

    Czech Academy of Sciences Publication Activity Database

    Meier-Haack, J.; Valko, M.; Lunkwitz, K.; Bleha, Miroslav

    Bratislava : Slovak Society of Chemical Engineering, 2003 - (Schlosser, Š.; Kertész, R.). s. 136 ISBN 80-227-1922-6. [Membrane Science and Technology Conference Permea. 07.09.2003-11.09.2003, Tatranské Matliare] R&D Projects: GA AV ?R KSK4050111 Institutional research plan: CEZ:AV0Z4050913 Keywords : fouling * blend membranes * polypropylene-polyamide Subject RIV: CD - Macromolecular Chemistry

  6. 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.)

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

    Directory of Open Access Journals (Sweden)

    Kamath B

    2006-01-01

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

  8. U10.0 Undulator conceptual design report

    Energy Technology Data Exchange (ETDEWEB)

    Hoyer, E.

    1994-06-01

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

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

    OpenAIRE

    Faten Debbabi; Saber Ben Abdessalem

    2011-01-01

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

  10. Study of metopic suture in south Indian skulls

    Directory of Open Access Journals (Sweden)

    Moula P. Akbar Basha

    2015-09-01

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

  11. 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.

  12. 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.

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

    Scientific Electronic Library Online (English)

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

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

  14. 21 CFR 878.4494 - Absorbable poly(hydroxybutyrate) surgical suture produced by recombinant DNA technology.

    Science.gov (United States)

    2010-04-01

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

  15. POLYPROPYLENE/CLAY NANOCOMPOSITES: SYNTHESIS AND CHARACTERIZATION

    OpenAIRE

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

    2010-01-01

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

  16. A simple sterile polypropylene fingernail substitute.

    Science.gov (United States)

    Tos, P; Artiaco, S; Coppolino, S; Conforti, L G; Battiston, B

    2009-06-01

    Traumatic nail injuries are often observed in clinical practice. Usually the fingernail can be preserved, cleaned and disinfected in order to use it in the reconstructive procedure. However, in some cases the nail can be avulsed and lost or too damaged to be used. In cases when the nail is not available it should be replaced by a substitute in order to protect nail bed and avoid adherences along the proximal nail bed and the nail fold. Furthermore the substitute serves to protect the tender nail bed from painful stimuli during the healing process. We used, as fingernail substitute, a polypropylene sheet in eight patients with fingernail avulsion or disruption. The polypropylene foil was trimmed reproducing the profile of the avulsed fingernail and thinned at the proximal edge to reduce thickness in order to ease the insertion into the nail fold. A small hole was then created in the center of the foil to allow blood drainage. The substitute was usually removed one month after the application. In our clinical experience we had not complications related to the polypropylene device. The new fingernail had good cosmetic appearance in most cases and all the patients reported a good protection of the fingertip during the healing period. The substitute used in this series is sterile, inexpensive and easily available in emergency and elective operatory theater. This polypropylene foil is flexible and can be shaped and adapted to the nail curvature radius. The substitute used in our clinical series protected the nail bed during healing until the growth of the new fingernail and respected our functional expectations. PMID:19428284

  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 polyp...

  18. Residual stress distribution in extruded polypropylene pipes.

    Czech Academy of Sciences Publication Activity Database

    Poduška, Jan; Ku?era, J.; Huta?, Pavel; Šev?ík, Martin; K?ivánek, J.; Sadílek, J.; Náhlík, Luboš

    2014-01-01

    Ro?. 2014, ?. 40 (2014), s. 88-98. ISSN 0142-9418 R&D Projects: GA ?R(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

  19. 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.

  20. Effects of ?-ray irradiation on polypropylene

    International Nuclear Information System (INIS)

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

  1. Cyclic viscoelastoplasticity of polypropylene/nanoclay composites

    DEFF Research Database (Denmark)

    Drozdov, A.; Christiansen, Jesper de Claville

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Maria de Fátima V. Marques

    2001-10-01

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

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

    Scientific Electronic Library Online (English)

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

    2001-10-01

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

  4. 21 CFR 878.4495 - Stainless steel suture.

    Science.gov (United States)

    2010-04-01

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

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

    OpenAIRE

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Faten Debbabi

    2011-01-01

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

  7. 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.

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

    DEFF Research Database (Denmark)

    SØrensen, Lars SchiØtt Technical University of Denmark,

    2003-01-01

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

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

    Science.gov (United States)

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

    2002-09-01

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

  10. Complications with mechanical suture use in colorectal surgery

    International Nuclear Information System (INIS)

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

  11. Crystallization of polypropylene at high cooling rates

    OpenAIRE

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

    2009-01-01

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

  12. 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

  13. Improved oil spill recovery using polypropylene fabric

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Carlos Lehmann

    2007-06-01

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

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

    Scientific Electronic Library Online (English)

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

    2007-06-01

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

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

    Science.gov (United States)

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

    2010-11-01

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

  17. 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.

  18. Ophiolite belts in the sw-iberian variscan suture

    OpenAIRE

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

    2008-01-01

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

  19. Mechanical force-induced midpalatal suture remodeling in mice

    OpenAIRE

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

    2007-01-01

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

  20. ASTIGMATIC OUTCOME & POST OPERATIVE RECOVERY IN PAT IENTS UNDERGOING PTERYGIUM EXCISION WITH CONJUNCTIVAL AUTOGRAFTS. COMPARISION BETWEEN SUTURE & AUTOLOGUS BLOOD FIBRIN

    Directory of Open Access Journals (Sweden)

    Smita Dileep

    2013-06-01

    Full Text Available ABSTRACT : AIMS: To review the effect of surgery type on the postop erative recovery & astigmatism in pterygium surgery. SETTINGS AND DESIGN: Randomized comparative clinical trial. MATERIALS AND METHODS: Forty six patients (46 eyes with primary pterygiu m were randomised to undergo pterygium surgery using eithe r autologous fibrin glue (23 eyes or 10-0 nylon sutures (23 eyes to attach the conjunctival autograft. The patients were followed up 1day, 1wk, 2wks & 6 w eeks. Outcome measures were keratometry changes & postope rative recovery.. The preoperative and postoperative keratometric measurements, evaluated using keratometer, were noted. RESULTS: Corneal astigmatism was significantly reduced in th e total group from 2.94(SD- 0.52 diopter to 1.91 (sd 0.57 diopter (p 0.05. The intensity of the postoperative watering, itchin g, were significantly lower in the autologous fibrin glue group than in the suture gro up (p<0.001. Postoperative redness was absent in 47.82% (11cases and mild in 52.18% (13 cases 2 weeks postoperatively in the autologous fibrin group while in sutured group 17.4% (4cases had mild redness and 82.6% (19 cases had moderate redness 2weeks postoperatively.

  1. 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

  2. Cell proliferation and osteogenic differentiation of growing pig cranial sutures.

    Science.gov (United States)

    Sun, Zongyang; Lee, Eugenia; Herring, Susan W

    2007-09-01

    Bone growth at the cranial sutures relies on proliferation of osteogenic progenitor cells and/or differentiation of osteoblasts. The current study was undertaken to assess these events in relation to suture growth and fusion. A total of 21 pigs, divided into three age groups (0.5-1.5 months, 3-4 months and 5-7 months), were used for immunohistochemical evaluation of cell proliferation (BrdU) and osteogenic differentiation (Cbfa1/Runx2) in the interfrontal and interparietal sutures. Proliferation and osteogenic differentiation were both more prominent near the bone fronts than in the central zone. With age, both proliferation and osteogenic differentiation diminished. Proliferation ceased on the endocranial (dura mater) side by the age of 3-4 months. Proliferation on the pericranial side was accompanied by active bone formation and initiation of suture fusion from this side. In conclusion, (1) decreased suture bone growth with age reflects decreased cell proliferation and probably also osteogenic differentiation, and (2) suture fusion occurs from the pericranial side where activity remains relatively high. PMID:17593220

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

    Science.gov (United States)

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

    2015-01-01

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

  4. 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.

  5. Mallet finger deformities treated by buried purse-string suture

    Directory of Open Access Journals (Sweden)

    YAO Jian-min

    2012-02-01

    Full Text Available ?Abstract?Objective: To investigate the efficacy of buried purse-string suture in the treatment of mallet finger deformities. Methods: From February 2009 to February 2010, 12 patients with closed non-fracture mallet fingers were treated by buried purse-string suture. The rupture tendons were sutured by purse-string suture with an atraumatic needle, and the knots were buried under subcutaneous tissue. Ex- ternal fixator was used at the extension position of the finger every night within three weeks after operation. Results: All patients were followed up for 6-12 months,mean 7 months. According to the Patel’s evaluation criteria, 2 cases (17% obtained excellent results, 7 good (58%, 2 fair (17% and 1 poor (8%. The overall rate of the cases with excellent and good outcomes was 75%. Conclusion: Buried purse-string suture is an easy and effective way to treat mallet finger deformities, with no serious postoperative complications or no need for reoperation. Key words: Tendon injuries; Finger injuries; Suture techniques; External fixator

  6. 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.

  7. 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.

  8. 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.)

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

    Directory of Open Access Journals (Sweden)

    Edélcio Vieira

    2004-12-01

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

  10. Electrophysical Properties of Composites Based on Atactic Polypropylene

    Science.gov (United States)

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

    2014-07-01

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

  11. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-10

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

  13. 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.

  14. 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.)

  15. POLYPROPYLENE/CLAY NANOCOMPOSITES: SYNTHESIS AND CHARACTERIZATION

    Scientific Electronic Library Online (English)

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

    2010-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Stephen H Cummings

    2012-07-01

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

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

    Science.gov (United States)

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

    2012-01-01

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

  18. In vivo oxidative degradation of polypropylene pelvic mesh.

    Science.gov (United States)

    Imel, Adam; Malmgren, Thomas; Dadmun, Mark; Gido, Samuel; Mays, Jimmy

    2015-12-01

    Commercial polypropylene pelvic mesh products were characterized in terms of their chemical compositions and molecular weight characteristics before and after implantation. These isotactic polypropylene mesh materials showed clear signs of oxidation by both Fourier-transform infrared spectroscopy and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS). The oxidation was accompanied by a decrease in both weight-average and z-average molecular weights and narrowing of the polydispersity index relative to that of the non-implanted material. SEM revealed the formation of transverse cracking of the fibers which generally, but with some exceptions, increased with implantation time. Collectively these results, as well as the loss of flexibility and embrittlement of polypropylene upon implantation as reported by other workers, may only be explained by in vivo oxidative degradation of polypropylene. PMID:26408998

  19. Radiation cross-linking of montmorillonite/polypropylene composite

    International Nuclear Information System (INIS)

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

  20. Thermal conductivity of polypropylene filled with inorganic particles

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-02-15

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

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

    International Nuclear Information System (INIS)

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

  2. 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)

  3. 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)

  4. Graft copolymerization of acrylonitrile onto polypropylene membrane by preirradiation

    International Nuclear Information System (INIS)

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

  5. 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...

  6. Radiation resistant modified polypropylene; Polipropylen modyfikowany odporny radiacyjnie

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

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

    OpenAIRE

    K Sudhakar,; Ch. Srinivas

    2014-01-01

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

  8. 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...

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

    DEFF Research Database (Denmark)

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

    1999-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Elif Sar?

    2014-12-01

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

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

    International Nuclear Information System (INIS)

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

  12. Later reproductive health after B-Lynch sutures

    DEFF Research Database (Denmark)

    Fuglsang, Jens

    2014-01-01

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

  13. 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.)

  14. Cranial sutures work collectively to distribute strain throughout the reptile skull

    OpenAIRE

    Curtis, Neil; Jones, M. E. H.; Evans, S. E.; O'Higgins, P.; Fagan, M. J.

    2013-01-01

    The skull is composed of many bones that come together at sutures. These sutures are important sites of growth, and as growth ceases some become fused while others remain patent. Their mechanical behaviour and how they interact with changing form and loadings to ensure balanced craniofacial development is still poorly understood. Early suture fusion often leads to disfiguring syndromes, thus is it imperative that we understand the function of sutures more clearly. By applying advanced enginee...

  15. Healing of the Goat Anterior Cruciate Ligament After a New Suture Repair Technique and Bioscaffold Treatment

    OpenAIRE

    Nguyen, D. Tan; Geel, Jurre; Schulze, Martin; Raschke, Michael J; Woo, Savio L-Y; van Dijk, C Niek; Blankevoort, Leendert

    2013-01-01

    Primary suture repair of the anterior cruciate ligament (ACL) has been used clinically in an attempt to heal the ruptured ACL. The results, however, were not satisfactory, which in retrospect can be attributed to the used suturing technique and the suboptimal healing conditions. These constraining conditions can be improved by introducing a new suturing technique and by using small intestinal submucosa (SIS) as a bioscaffold. It is hypothesized that the suturing technique keep the torn ends t...

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

    OpenAIRE

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

    2013-01-01

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

  17. 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

  18. Polypropylene matrix composites reinforced with coconut fibers

    Directory of Open Access Journals (Sweden)

    Maria Virginia Gelfuso

    2011-09-01

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

  19. Surface modification of polypropylene based particle foams

    Science.gov (United States)

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

    2014-05-01

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

  20. Polypropylene matrix composites reinforced with coconut fibers

    Scientific Electronic Library Online (English)

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

    2011-09-01

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

  1. 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.

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    Krki? Nevena M.

    2012-01-01

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

  4. 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.

  5. 21 CFR 878.4840 - Absorbable polydioxanone surgical suture.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4840 Absorbable... for the device is FDA's “Class II Special Controls Guidance Document: Surgical Sutures; Guidance for Industry and FDA.” See § 878.1(e) for the availability of this guidance document....

  6. 21 CFR 878.5030 - Natural nonabsorbable silk surgical suture.

    Science.gov (United States)

    2010-04-01

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

  7. 21 CFR 878.4830 - Absorbable surgical gut suture.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4830 Absorbable... approximation. (b) Classification. Class II (special controls). The special control for this device is FDA's “Class II Special Controls Guidance Document: Surgical Sutures; Guidance for Industry and FDA.” See §...

  8. 21 CFR 878.5020 - Nonabsorbable polyamide surgical suture.

    Science.gov (United States)

    2010-04-01

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

  9. Neonatal subperiosteal cephalohematoma crossing a synostosed sagittal suture

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-12-15

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

  10. Evaluation of Sternal Closure with Absorbable Polydioxanone Sutures in Children

    OpenAIRE

    Bigdelian, Hamid; Sedighi, Mohsen

    2014-01-01

    Introduction: Sternal dehiscence, sternal wound infection and mediastinitis are troublesome complications following median sternotomy which are major causes of morbidity and mortality of patients. Synthetic polydioxanone absorbable suture seems effective in prevention of these complications in children undergoing open heart surgery.

  11. Penile torsion correction by diagonal corporal plication sutures

    Scientific Electronic Library Online (English)

    Brent W., Snow.

    2009-02-01

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

  12. 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

  13. 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

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

    Directory of Open Access Journals (Sweden)

    Govedarica Dragan D.

    2015-01-01

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

  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. Preparation of organophilic clays and polypropylene nano composites

    International Nuclear Information System (INIS)

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

  17. 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)

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

    Scientific Electronic Library Online (English)

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

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

  19. 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.

  20. 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.

  1. Near-surface deformation in polypropylene blends

    Science.gov (United States)

    Tang, Honxiang

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

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

    Directory of Open Access Journals (Sweden)

    Fernandes MA

    2014-02-01

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

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

    Scientific Electronic Library Online (English)

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

    2012-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Juliano Hermes Maeso Montes

    2012-12-01

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

  5. 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.

  6. Study on photodegradationof injection-moulded .beta.-polypropylenes.

    Czech Academy of Sciences Publication Activity Database

    Obadal, M.; ?ermák, R.; Raab, Miroslav; Verney, V.; Commereuc, S.; Fraisse, F.

    2006-01-01

    Ro?. 91, 3-4 (2006), s. 459-463. ISSN 0141-3910 Institutional research plan: CEZ:AV0Z40500505 Keywords : . beta .-polypropylene * injection moulding * photo- oxidation Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.174, year: 2006

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

    International Nuclear Information System (INIS)

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

  8. Rheological behaviour of metallocene polypropylenes prepared by reactive extrusion process.

    Czech Academy of Sciences Publication Activity Database

    Pivokonský, Radek; Filip, Petr; Zatloukal, M.; Tzoganakis, C.

    Lisbon : European Society of Rheology, 2012. s. 394. [International Congress on Rheology /16./. 05.08.2012-10.08.2012, Lisbon] R&D Projects: GA ?R GA103/09/2066 Keywords : metallocene polypropylene * constitutive modelling * differential models Subject RIV: BK - Fluid Dynamics

  9. Nanogels and microgels of polypropylene obtained by gamma irradiation

    International Nuclear Information System (INIS)

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

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

    Czech Academy of Sciences Publication Activity Database

    Kotek, Ji?í; 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 ?R(CZ) IBS4050351 Keywords : polypropylene * nanocomposites * melt-compounding Subject RIV: CD - Macromolecular Chemistry

  11. 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...

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

    Directory of Open Access Journals (Sweden)

    M. T. T. Braga

    2000-01-01

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

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

    Scientific Electronic Library Online (English)

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

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

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

    Directory of Open Access Journals (Sweden)

    Lucilene B. de Paiva

    2006-06-01

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

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

    Scientific Electronic Library Online (English)

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

    2006-06-01

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

  16. Arthroscopic Absorbable Suture Fixation for Tibial Spine Fractures

    OpenAIRE

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

    2013-01-01

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

  17. Transcutaneous Serdev Suture For Buttock’s Lift

    OpenAIRE

    Nikolay Serdev

    2013-01-01

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

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

    OpenAIRE

    Beamish, D.; Smythe, D.K.

    1986-01-01

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

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

    OpenAIRE

    Evans, David M

    1991-01-01

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

  20. 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 ...

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

    Scientific Electronic Library Online (English)

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

    2003-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Mirkovi? Siniša

    2011-01-01

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

  3. 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.

  4. 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.

  5. 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)

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

    OpenAIRE

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

    1996-01-01

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

  7. The Importance of Craniofacial Sutures in Biomechanical Finite Element Models of the Domestic Pig

    OpenAIRE

    Bright, Jen A

    2012-01-01

    Craniofacial sutures are a ubiquitous feature of the vertebrate skull. Previous experimental work has shown that bone strain magnitudes and orientations often vary when moving from one bone to another, across a craniofacial suture. This has led to the hypothesis that craniofacial sutures act to modify the strain environment of the skull, possibly as a mode of dissipating high stresses generated during feeding or impact. This study tests the hypothesis that the introduction of craniofacial sut...

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

    OpenAIRE

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

    2007-01-01

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

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

    OpenAIRE

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

    2012-01-01

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

    Materials and Methods: The study includes 1...

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

    OpenAIRE

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

    1999-01-01

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

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

    OpenAIRE

    Berger, Cezar Augusto Sarraf; Mocelin, Marcos; Soares, Caio Márcio Correia; Pasinato, Rogério; Frota, Andreia Ellery

    2012-01-01

    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...

  12. The use of a new suture material (Polydioxanone) in the biliary tract.

    OpenAIRE

    Hoile, R W

    1983-01-01

    The use of a new synthetic absorbable suture material, polydioxanone, has been assessed over a period in excess of three years in 63 patients undergoing surgical procedures on the biliary tract. The material, which was used exclusively for all ligatures and sutures, has greater pliability and strength than other absorbable materials and was found to be highly satisfactory. No suture-related complications were identified and the handling properties of the material were excellent. This material...

  13. Effects of irradiated polypropylene compatibilizer on the properties of short carbon fiber reinforced polypropylene composites

    Science.gov (United States)

    Gamze Karsli, Nevin; Aytac, Ayse; Akbulut, Meshude; Deniz, Veli; Güven, Olgun

    2013-03-01

    In this study, the effects of irradiated polypropylene (PP) compatibilizer addition into PP matrix on the interfacial adhesion between the carbon fiber (CF) and PP matrix were investigated. Unirradiated and irradiated PPs were blended, and two types of carbon fibers; unsized (surface treated) and sized, were used for composites preparation. In order to characterize the physical and morphological properties of all CF reinforced composites prepared, tensile tests, differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and Positron annihilation lifetime spectroscopy (PALS) were performed. The strong compatibilizing effects of irradiated PP on the mechanical properties of composites were noticed. It has been found that breaking strength values were increased up to 30%. The compatibilizing effect of irradiated PP was also confirmed with SEM micrographs and PALS. It has been seen that blending PP matrix with irradiated PP improved the interfacial adhesion between the carbon fiber and matrix materials. The melting point temperatures of composites were not changed significantly for all composites. The results showed that irradiated PP as a compatibilizer together with unsized carbon fiber in place of sized carbon fiber can be used in order to improve the mechanical properties of carbon fiber reinforced PP composites.

  14. Improving metallized polypropylene film capacitors reliability; Amelioration de la fiabilite des condensateurs a films polypropylene metallises

    Energy Technology Data Exchange (ETDEWEB)

    El-Husseini, M.H.

    2001-12-01

    The study presented in this thesis is a contribution toward improving the reliability of Metallized Polypropylene Film (MPPF) capacitors achieved by a better design. A temperature distribution in the roll is assumed with the aim of optimizing its thermal performance. It appears that the heating of long capacitor is higher than that of equivalent flat capacitor subjected to the same electric stresses. Standard accelerated aging tests (temperature and voltage) of MPPF capacitors have been performed with the aim to evaluate the dielectric performance and thus the capacitor lifetime. The statistical approach showed that the failure mode may be represented by two parameter Weibull distribution and the experimental approach proved that long capacitor deteriorates faster than a plate-shaped having the same features. Although capacitors with long geometry seem to have a poor pulse handling performance, we found that the quality of the, end-edge contact is strongly dependent on the physics features of the manufacturing process. The end edge contact plays a vital role in the pulse handling capability of the MPPF capacitors which varies from few hundred to several dozen of thousand discharging cycles capability depending on the end-edge contact performance. (author)

  15. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-09-15

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

  17. 21 CFR 878.4493 - Absorbable poly(glycolide/l-lactide) surgical suture.

    Science.gov (United States)

    2010-04-01

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

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

    OpenAIRE

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

    2006-01-01

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

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

    OpenAIRE

    A.B. Kachiwal and A.B. Kalhoro

    2003-01-01

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

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

    DEFF Research Database (Denmark)

    Thorstad, Eva B.; Økland, Finn

    2013-01-01

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

  1. Brief communication: histology and micro CT as methods for assessment of facial suture patency.

    Science.gov (United States)

    Reinholt, Lauren E; Burrows, Anne M; Eiting, Thomas P; Dumont, Elizabeth R; Smith, Timothy D

    2009-04-01

    The extent of fusion in facial sutures has implications for topics ranging from biomechanics to phylogeny reconstruction. An unfortunate limitation of studying sutural fusion in skeletal specimens is that it is difficult to assess whether apparently patent sutures are in fact fused internally. Both histology and microcomputed tomography (CT) are potential tools for solving this, but relatively few studies have attempted to discern the limits of micro CT for visualization of microanatomical structures. We examined microanatomical aspects of facial sutures in adult cadaveric samples from captive bushbabies. Premaxillary and nasopremaxillary sutures were examined in serially sectioned snouts of four greater bushbabies (Otolemur garnettii) and four lesser bushbabies (Galago moholi). Sections containing sutures with osseous bridging were rated as "fused," and the presence or absence of grooves on the external side was recorded. One bushbaby was studied using micro CT prior to physical sectioning. O. garnettii and two of the G. moholi show multiple foci of fusion. Histological examination confirmed that sutural fusion is limited to the internal surface in numerous sections, resulting in an external notch. Such points of internal fusion could be clearly visualized in raw CT slices. The presence of such notches suggests that external examination can underestimate the degree of suture fusion. Thus, microanatomical evidence may be needed to fully assess biomechanical correlates and phylogenetic interpretations based on fusion of facial sutures. Our results also indicate micro CT may be a useful tool to obtain this evidence. PMID:19170212

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

    Science.gov (United States)

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

    2015-09-16

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

  3. 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.

  4. 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.

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

    DEFF Research Database (Denmark)

    Fuglsang, Jens

    2014-01-01

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

  6. 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

  7. 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.

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

    Scientific Electronic Library Online (English)

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

    2005-06-01

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

  9. DSC Study on Polypropylene Modified with Calcium Carbonate Nanoparticles

    International Nuclear Information System (INIS)

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

  10. 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)

  11. Rheological and Thermal Behavior of Polypropylene-Kaolin Composites

    International Nuclear Information System (INIS)

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

  12. 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)

  13. POLYPROPYLENE/STARCH BLENDS: STUDY OF THERMAL AND MORPHOLOGICAL PROPERTIES

    Scientific Electronic Library Online (English)

    MONICA A, PÉREZ R; BERNABÉ L, RIVAS Q; SADDYS, RODRÍGUEZ-LLAMAZARES.

    2013-03-01

    Full Text Available Polypropylene/starch blends were prepared using starch of different botanical source. The influence of starch type and starch content on thermal properties and morphology of polypropylene/starch blends was studied. Corn and potato starches were used as starch source. The starch content in the blends [...] was 7 and 15 wt-%. Characterization of PP and PP/starch blends by (DSC), (TGA), and (SEM) was carried out to obtain information on miscibility among PP and starch. The starch domains exhibited characteristic voids be due to thermal degradation. Two types of PP, PP1 poly(propylene-co-ethylene), random copolymer, and PP3 poly(propylene-co-ethylene), heterophasic copolymer were studied.

  14. 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)

  15. 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...

  16. 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...

  17. 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...

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

    OpenAIRE

    Cobzaru, Cecilia

    2006-01-01

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

  19. Fracture Toughness of Polypropylene-Based Particulate Composites

    OpenAIRE

    David Arencón; José Ignacio Velasco

    2009-01-01

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

  20. Fracture toughness of injection moulded organoclay reinforced polypropylene composites

    OpenAIRE

    Pettarin, V.; Brun, F; A. J. Pontes; Viana, J. C.; 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...

  1. Die Rätsel der .beta.-Phase in isotaktischem Polypropylen.

    Czech Academy of Sciences Publication Activity Database

    Raab, Miroslav; Kotek, Ji?í; Grellmann, W.

    HalleWittenberg : MartinLutherUniversität, 2003, s. -. [Tagung Deformation und Bruchverhalten von Kunststoffen /9./. Halle-Wittenberg (DE), 25.06.2003-27.06.2003] R&D Projects: GA ?R GA106/02/1249; GA ?R GP106/02/P027 Institutional research plan: CEZ:AV0Z4050913 Keywords : isotactic polypropylene * .beta. nucleation * hierarchical structure Subject RIV: CD - Macromolecular Chemistry

  2. Mechanical properties of polypropylene/calcium carbonate nanocomposites

    OpenAIRE

    Daniel Eiras; Luiz Antonio Pessan

    2009-01-01

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

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

    OpenAIRE

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

    2007-01-01

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

  4. 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)

  5. Comparison of surface properties of selected polypropylenes: influence of maleation.

    Czech Academy of Sciences Publication Activity Database

    J?za, Josef; Novák, I.; Florián, Š.; Pollák, V.

    Praha : Ústav makromolekulární chemie AV ?R, 2006. P15/1-P15/4. ISBN 80-85009-54-4. [?esko - Slovenská konference Polymery /4./. 17.09.2006-20.09.2006, T?eš?] R&D Projects: GA ?R GA106/06/0729 Institutional research plan: CEZ:AV0Z40500505 Keywords : polypropylene * grafted * maleined Subject RIV: CD - Macromolecular Chemistry

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    With the aim of creating tough nanocomposits (NC) [1] based on polypropylene (PP) and nanoclay (NCl) in the framework of the 7th EU program NANOTOUGH we have designed amphiphilic block copolymers utilizing Atom Transfer Radical Polymerization (ATRP) [2]. They consist of a hydrophobic block of Kraton L-1203 from Kuraray Co., Japan with molecular weight 7000 and PDI=1.05, and a hydrophilic block of quaternized dimethylaminoethyl methacrylate (DMAEMA). The size of the hydrophilic block was varied, ...

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

    Scientific Electronic Library Online (English)

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

    2000-04-01

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

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

    OpenAIRE

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

    2000-01-01

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

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

    OpenAIRE

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

    2002-01-01

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

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

    OpenAIRE

    M.T. T. Braga; Gabrielli, C.; A. Souza; 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...

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

    Science.gov (United States)

    Papasakelariou

    1996-08-01

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

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

    Science.gov (United States)

    Tsao, Sean W; Holz, Huck A

    2015-03-01

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

  13. Sternal Closure With An Absorbable Loop Suture ?n Children

    OpenAIRE

    KEÇEL?G?L, H.T.; KOLBAKIR,, F.; SARAÇ, A.; DEM?R, Z.; ?R?Z, E.; KÜSDÜL, M.; DEM?R, ?.

    2010-01-01

    The reliability of polydioxanone (PDS) suture for sternal closure was tested on 264 consecutive sternotomies in our department from April 1987 to May 1998. The reason of sternotomy was tetralogy of Fallot in 65 cases (24.62%), ventricular septal defect (VSD) in 38 cases (14. 39%), atrial septal defect (ASD) in 77 cases (29.16%), ASD+VSD in 23 (8.71%), mitral valve replacement in 22 cases (8.33%), aortic valve replacement in 10 cases (3.78%) and other cardiac disorders in 29 cases (10.98%). St...

  14. Flame retardant polypropylene nanocomposites reinforced with surface treated carbon nanotubes

    Science.gov (United States)

    Guleria, Abhishant

    Polypropylene nanocomposites are prepared by reinforcing carbon nanotubes by ex-situ solution mixing method. Interfacial dispersion of carbon nanotubes in polypropylene have been improved by surface modification of CNTs and adding surfactants. Polypropylene nanocomposites fabrication was done after treating CNTs. Firstly, oxidation of CNTs followed by silanization for addition of functionalized groups on the surface of CNTs. Maleic anhydride grafted PPs were used as surfactants. Maleic anhydrides with two different molecular weights were LAMPP and HMAPP. Successful oxidation of CNTs by nitric acid and functionalized CNTs by 3-Aminopropyltriethoxysilane was confirmed by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) with evidence of absorption peak at 1700 and 1100-1000 cm-1. Scanning electron microscopy (SEM) micrographs revealed that the CNTs dispersion quality was improved by directly adding LMAPP/HMAPP into PP/CNTs system and the PP-CNTs adhesion was enhanced through both the CNTs surface treatment and the addition of surfactant. Thermal gravimetric analysis (TGA) revealed an enhanced thermal stability in the PP/CNTs and PP/CNTs/MAPP. Differential scanning calorimetry (DSC) characterization demonstrated that the crystalline temperature, fusion heat and crystalline fraction of hosting PP were decreased with the introduction of CNTs and surface treated CNTs; however, melting temperature was only slightly changed. Melting rheological behaviors including complex viscosity, storage modulus, and loss modulus indicated significant changes in the PP/MAPP/CNTs system before and after functionalization of CNTs, and the mechanism were also discussed in details.

  15. 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.

  16. Mixing of Isotactic and Syndiotactic Polypropylenes in the Melt

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-07-14

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

  17. Pubovaginal sling with a low-cost polypropylene mesh

    Directory of Open Access Journals (Sweden)

    Fransber R. Rodrigues

    2007-10-01

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

  18. 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.

  19. Polypropylene–clay composite prepared from Indian bentonite

    Indian Academy of Sciences (India)

    Madhuchhanda Sarkar; Kausik Dana; Sankar Ghatak; Amarnath Banerjee

    2008-02-01

    In the present work, a set of experimental polypropylene (PP) clay composites containing pristine bentonite clay of Indian origin has been prepared and then characterized. The polymer clay composites are processed by solution mixing of polypropylene with bentonite clay using a solvent xylene and high speed electric stirrer at a temperature around 130°C and then by compression molding at 170°C. The mechanical properties of PP–clay composites like tensile strength, hardness and impact resistance have been investigated. Microstructural studies were carried out using scanning electron microscope and transmission electron microscope and the thermal properties were studied using differential scanning calorimeter. Mechanical properties of the prepared composites showed highest reinforcing and toughening effects of the clay filler at a loading of only 5 mass % in PP matrix. Tensile strength was observed to be highest in case of 5 mass % of clay loading and it was more than 14% of that of the neat PP, while toughness increased by more than 80%. Bentonite clay–PP composite (5 mass %) also showed 60% increase in impact energy value. However, no significant change was observed in case of hardness and tensile modulus. Higher percentages of bentonite clay did not further improve the properties with respect to pristine polypropylene. The study of the microstructure of the prepared polymer layered silicate clay composites showed a mixed morphology with multiple stacks of clay layers and tactoids of different thicknesses.

  20. Pubovaginal sling with a low-cost polypropylene mesh

    Scientific Electronic Library Online (English)

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

    2007-10-01

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

  1. 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.

  2. 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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2006-01-01

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

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

    OpenAIRE

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

    2015-01-01

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

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

    Scientific Electronic Library Online (English)

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

    2015-06-01

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

  7. An experimental model to retraining in microvascular suture

    Scientific Electronic Library Online (English)

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

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

  8. 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

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

    Science.gov (United States)

    Badia, Alejandro; Jiménez, Alexis

    2006-10-01

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

  10. Biomechanical features of bidirectional-barbed suture: a randomized laboratory analysis.

    Science.gov (United States)

    Castaldi, Maria Antonietta; Cobellis, Luigi; Fraternali, Fernando; Ardovino, Mario; Ardovino, Italo; Colacurci, Nicola

    2014-03-01

    The aim of the current prospective study was to evaluate the biomechanical stability of barbed suture vs. conventional suture. Biomechanical stability of a 14x14-cm PDO/polydioxanone, with a half circle and 36-mm needle, bidirectional barbed 0-Quill suture (Angiotech, Vancouver, British Columbia, Canada) vs. 1-Poliglecaprone 25 (Monocryl, Ethicon, Inc, Somerville, NJ) suture was evaluated on biological specimens. The 1-Monocryl suture was chosen because it is widely used by gynecological surgeons in the repair either of the vaginal cuff or the uterine wall defects. Forty specimens of aponeurotic muscle, obtained from abdominal wall of a lamb, were prepared, and randomly assigned to 1 of 2 repair groups: Group A (n = 20) classic repair with 1-Monocryl suture; Group B (n = 20) 0-Quill barbed suture. Each specimen was transected at the midpoint and then repaired. Biomechanical stability of the repaired specimen was verified on a CMT6000 electromechanical universal testing machine (SANS, MTS SYSTEMS, China Co., Ltd., Shenzhen, China), with a 1kN cell. Biomechanical tests showed that maximum force was similar for 1-Monocryl and 0-Quill respectively (p = non-significant). This randomized laboratory study shows that biomechanical stability of the sutures is comparable. PMID:24700213

  11. Thermal Characterizations of Silver-containing Bioactive Glass-coated Sutures

    OpenAIRE

    Blaker, Jonny J.; Boccaccini, Aldo R.; Nazhat, Showan N

    2005-01-01

    Abstract This study utilized and compared a number of thermal analysis methods to characterize the thermal properties of commercial sutures with and without antimicrobial coatings of silver-doped bioactive glass (AgBG) interlocking particulates. The effect of a slurry dipping technique used to coat resorbable Vicryl® (polyglactin 910) and non-resorbable Mersilk® surgical sutures with AgBG was investigated ...

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

    Science.gov (United States)

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

    2014-05-01

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

  13. 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.

  14. 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...

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

    OpenAIRE

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

    2013-01-01

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

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

    OpenAIRE

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

    2006-01-01

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

  17. 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...

  18. The effect of specific nucleation on tensile mechanical behaviour of isotactic polypropylene.

    Czech Academy of Sciences Publication Activity Database

    Raab, Miroslav; Š?udla, Jaroslav; Kola?ík, Jan

    2004-01-01

    Ro?. 40, ?. 7 (2004), s. 1317-1323. ISSN 0014-3057 R&D Projects: GA AV ?R IAA4050105; GA ?R GA106/02/1249 Institutional research plan: CEZ:AV0Z4050913 Keywords : polypropylene * nucleating agents * .Beta.-phase in polypropylene Subject RIV: JJ - Other Materials Impact factor: 1.419, year: 2004

  19. 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

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

    Science.gov (United States)

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

    2014-12-01

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

  1. Transcutaneous Serdev Suture For Buttock’s 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".

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

    Directory of Open Access Journals (Sweden)

    Li ZR

    2012-03-01

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

  3. 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...

  4. 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.

  5. 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)

  6. 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.

  7. 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.

  8. 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.

  9. Electron-beam processing of wood fiber reinforced polypropylene

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

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

    2012-01-01

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

  11. Mechanical and Morphological Properties of Polypropylene/Polyoxymethylene Blends

    OpenAIRE

    Sirirat Wacharawichanant; Tanakorn Siripattanasak

    2013-01-01

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  13. 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...

  14. 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, Ji?ina; 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 ?R GA106/04/1118; GA ?R 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

  15. Rheological behaviour of polypropylene blends utilized in foaming process.

    Czech Academy of Sciences Publication Activity Database

    Piyamanocha, P.; Sedlá?ek, 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. 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.)

  17. 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.)

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Vikash Lal

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    F.Eshghi

    2006-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Vogt Peter M

    2009-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Mevci Özdemir

    2014-09-01

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

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

    Science.gov (United States)

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

    2014-02-01

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

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Science.gov (United States)

    Lin, Y L; Cai, J H

    1997-05-01

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

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

    Science.gov (United States)

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

    2006-01-01

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

  7. Morphology and properties of recycled polypropylene/bamboo fibers composites

    Science.gov (United States)

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

    2011-05-01

    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.

  8. 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.

  9. 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.

  10. Investigation of Fibres Migration in Cotton/Polypropylene Blended Yarn

    Directory of Open Access Journals (Sweden)

    Dzmitry RYKLIN

    2014-09-01

    Full Text Available This study is devoted to theoretical and experimental research of fibres migration in blended yarns. A hypothesis states that due to fibres migration their tension in yarn becomes equal. On the basis of that hypothesis, we identified the factors that affect the migration. The main factors influencing are differences in Young's modulus and density of fibres. Simulating the fibres migration we obtained the formulae for determining the proportion of fibres in the external and inner layers of blended yarn. These formulae were proved by analysis of cross-section of cotton/polypropylene yarn. Results of blended yarn processing in knitting showed that migration of polypropylene fibres in direction to the yarn surface leads to significant increase of yarn breakages due to growth of its friction coefficient. Reduction of the input yarn tension by 10 % – 15 % helped to stabilize the process of knitting. It was found that the usage of theoretical information about fibres migration allows to draw conclusions about the necessity of adjustments to settings of subsequent processing of blended yarns. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4610

  11. Aging effects of polypropylene used in heating systems

    International Nuclear Information System (INIS)

    The ageing effects of polypropylene targets used in heating systems were investigated using the nuclear reaction analysis (NRA) technique. Deuterium beams of energies 900, 1200 and 1500 keV, supplied from the University of Jordan Van de Graaff accelerator, were employed. Different working times between 1 and 6 years were investigated in addition to a new fresh sample which was considered as standard. The reactions resulting from 12C(d,p)13C, 16O(d,p1)17O and 14N(d,?1)12C were monitored. The oxygen and nitrogen concentrations data reveal similar behaviour for both elements. The initial concentration of both quantities resulting from fusion, processing and storage times decreases and then gradually increases to reach higher levels than those initially, as the working time is increased. A model, based on mass transfer of air-oxygen and nitrogen and solubility of polypropylene to both elements, was proposed to explain our observation. The uptake of these light impurities and their presence at high concentration levels in the thermopipes material, in addition to microstructural effects, are responsible for the degradation of many of its observed properties. The main effect was demonstrated by the influence of several parameters on strength and embrittlement. (Author)

  12. 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.

  13. 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.

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

    Science.gov (United States)

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

    2015-11-01

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

  15. Incidence of Sutural Bones at Asterion in Adults Indians Skulls Incidencia de Huesos Suturales en el Asterion de Cráneos Indios Adultos

    OpenAIRE

    Rajani Singh

    2012-01-01

    Asterion is the point of sutural confluence observed in normal lateralis of the skull where parietal, temporal and occipital bone meet. Present study was carried out in the Department of Anatomy, CSM Medical University, Lucknow using fifty five dry human skulls to analyse the incidence of sutural bones at the asterion and its variation. At the asterion, sutural morphology was classified into two types: Type I- Where a sutural bone was present and Type II- Where a sutural bone was absent. Amon...

  16. Comparison of rheological and mechanical properties of modified polypropylene - short glass fiber composites

    International Nuclear Information System (INIS)

    Short glass fiber (SGF) reinforced composite materials were principally fabricated using polypropylene (PP) as thermo-plastic matrix. Short glass fiber and polypropylene frequently suffer from lack of adequate fiber-matrix adhesion. This problem was addressed by grafting polypropylene (PP) with maleic anhydride (MA) in the presence of benzyl peroxide (BPO) as an initiator. The results revealed that by increasing fiber contents from 5 to 40 %, tensile strength increases while elongation at break decreases. Rheological behavior was found to be pseudoplastic, whereas viscosity increases by increasing SGF contents. A decrease in die swell was observed with increase in SGF contents. (author)

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

    Directory of Open Access Journals (Sweden)

    R. S. Rajguru,

    2014-06-01

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

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

    International Nuclear Information System (INIS)

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

  19. Learning curve of transumbilical suture-suspension single-incision laparoscopic cholecystectomy

    OpenAIRE

    Ming-Xin Pan; Zhi-Wei Liang; Yuan Cheng; Ze-Sheng Jiang; Xiao-Ping Xu; Kang-Hua Wang; Hai-Yan Liu; Yi Gao

    2013-01-01

    AIM: To investigate the learning curve of transumbilical suture-suspension single-incision laparoscopic cholecystectomy (SILC). METHODS: The clinical data of 180 consecutive transumbilical suture-suspension SILCs performed by a team in our department during the period from August 2009 to March 2011 were retrospectively analyzed. Patients were divided into nine groups according to operation dates, and each group included 20 patients operated on consecutively in each time period. The surgical o...

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

    OpenAIRE

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Abhay Nilkanth Datarkar

    2014-09-01

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

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

    OpenAIRE

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

    2013-01-01

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

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

    OpenAIRE

    Tarabishy, Ahmad B.; Steinemann, Thomas L

    2010-01-01

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

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

    OpenAIRE

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

    2012-01-01

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

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

    OpenAIRE

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

    2004-01-01

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

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

    OpenAIRE

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

    2012-01-01

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

  8. Assessment of sutures for use in colonic surgery: an experimental study.

    OpenAIRE

    Durdey, P; Bucknall, T. E.

    1984-01-01

    Following injury, normal colon takes approximately 30 days to regain full breaking strength. This healing period can be lengthened by local infection. Colonic anastomoses are likely to be contaminated by intraluminal organisms, and suture material in such a situation is known to potentiate the development of sepsis. Experiments were designed to evaluate six suture materials used in colonic surgery to determine which retained adequate tensile strength and which excited least inflammatory respo...

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

    OpenAIRE

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

    2009-01-01

    Abstract Background Treatment of ruptured Achilles tendons currently constitutes of conservative early functional treatment or surgical treatment either by open or minimal invasive techniques. We hypothesize that an experimental Achilles tendon suture in an animal model significantly deteriorates Achilles tendon microcirculation immediately following suturing. Methods Fifteen Achilles tendons of eight male Wistar rats (275–325 g) were included. After preparation of the Achilles tendon with a ...

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

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

    DEFF Research Database (Denmark)

    Jorgensen, L N; Sommer, T; Assaadzadeh, S; Strand, L; Dorfelt, A; Hensler, Margaret Kathryn; Rosenberg, J; Sommer, Thorbjørn

    2012-01-01

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

  12. Estudo comparativo, em cães, entre a anastomose esôfago-esofágica cervical em dois planos de sutura e a em um plano único extramucoso Study in dogs comparing esophagus-esophageal cervical anastomosis in two planes of suture versus a single extramucosal plane

    Directory of Open Access Journals (Sweden)

    Amaury José Teixeira Nigro

    1997-03-01

    Full Text Available O objetivo é comparar a eficácia entre as anastomoses esôfago-esofágicas cervicais em dois planos de sutura com as feitas em um plano único extramucoso. Utilizou-se 60 cães, sadios, sem raça definida, de ambos os sexos, com peso médio de 15 kg. Foram separados em dois grupos iguais: no GRUPO I será feita a anastomose em dois planos de sutura e, no GRUPO II, a em um plano único extramucoso. Cada grupo foi subdividido em 3 subgrupos iguais, e para cada um deles foi estabelecido um determinado período de observação pós-operatório (PO de 7, 14 e 30 dias, respectivamente. As suturas foram feitas sempre com fio de polipropileno 4 zeros. Avaliou-se a incidência de complicações pós-operatórias imediatas e tardias e às características histológicas da cicatrização de cada tipo de anastomose. A análise estatística dos dados coletados permitiu verificar que na anastomose esôfago-esofágica cervical executada em um plano único extramucoso a porcentagem de fistulas (13,6%, e de estenoses (30% ao nível da zona de sutura foi significantemente menor do que a observada na sutura realizada em dois planos de sutura em que as porcentagens foram de (26,7% e (63,4%, respectivamente. A cicatrização das estruturas da parede esofágica ao nível da anastomose também foi significantemente melhor na anastomose em plano único extramucoso do que na em dois planos de sutura. Os resultados observados permitiram concluir que a anastomose em plano único extramucoso é mais eficaz do que a executada em dois planos de sutura.The objective of our study was to compare the efficacy of two types of cervical esophagus-esophageal anastomoses: two planes of suture versus a single extramucosal suture. Sixty healthy mongrel dogs of both sexes with a medium body weight of 15 kg. Were separated into two groups. Group one: anastomosis using two planes of suture; and Group two: anastomosis using one plane of extramucosal suture. Each group was divided into three subgroups based on post-operative time periods: 7, 14 and 30 days. Polypropylene 4-0 sutures were used in all anastomoses. The incidence of early and late post-operative complications and histological characteristics of the healing process at the site of the anastomoses were evaluated. Statistical analyses of the data collected permitted verification that the cervical esophagus-esophageal anastomoses done by only the extramucosal suture showed an incidence of 13.6% fistula and 30% stenosis at the level of the suture zone, which was significantly lower as compared to that observed in the two plane suture repair group where the percentages were 26.7 and 63.4 respectively. The healing of the structure of the esophageal wall at the level of the anastomosis was also significantly improved in the single plane extramucosal anastomosis group as compared to the two plane suture group. The observed results permitted conclusion that the extramucosal anastomosis in a single plane is more effícacious than that executed in two suture planes.

  13. Estudo comparativo, em cães, entre a anastomose esôfago-esofágica cervical em dois planos de sutura e a em um plano único extramucoso / Study in dogs comparing esophagus-esophageal cervical anastomosis in two planes of suture versus a single extramucosal plane

    Scientific Electronic Library Online (English)

    Amaury José Teixeira, Nigro; Neil Ferreira, Novo; Yara, Juliano.

    1997-03-01

    Full Text Available O objetivo é comparar a eficácia entre as anastomoses esôfago-esofágicas cervicais em dois planos de sutura com as feitas em um plano único extramucoso. Utilizou-se 60 cães, sadios, sem raça definida, de ambos os sexos, com peso médio de 15 kg. Foram separados em dois grupos iguais: no GRUPO I será [...] feita a anastomose em dois planos de sutura e, no GRUPO II, a em um plano único extramucoso. Cada grupo foi subdividido em 3 subgrupos iguais, e para cada um deles foi estabelecido um determinado período de observação pós-operatório (PO) de 7, 14 e 30 dias, respectivamente. As suturas foram feitas sempre com fio de polipropileno 4 zeros. Avaliou-se a incidência de complicações pós-operatórias imediatas e tardias e às características histológicas da cicatrização de cada tipo de anastomose. A análise estatística dos dados coletados permitiu verificar que na anastomose esôfago-esofágica cervical executada em um plano único extramucoso a porcentagem de fistulas (13,6%), e de estenoses (30%) ao nível da zona de sutura foi significantemente menor do que a observada na sutura realizada em dois planos de sutura em que as porcentagens foram de (26,7%) e (63,4%), respectivamente. A cicatrização das estruturas da parede esofágica ao nível da anastomose também foi significantemente melhor na anastomose em plano único extramucoso do que na em dois planos de sutura. Os resultados observados permitiram concluir que a anastomose em plano único extramucoso é mais eficaz do que a executada em dois planos de sutura. Abstract in english The objective of our study was to compare the efficacy of two types of cervical esophagus-esophageal anastomoses: two planes of suture versus a single extramucosal suture. Sixty healthy mongrel dogs of both sexes with a medium body weight of 15 kg. Were separated into two groups. Group one: anastomo [...] sis using two planes of suture; and Group two: anastomosis using one plane of extramucosal suture. Each group was divided into three subgroups based on post-operative time periods: 7, 14 and 30 days. Polypropylene 4-0 sutures were used in all anastomoses. The incidence of early and late post-operative complications and histological characteristics of the healing process at the site of the anastomoses were evaluated. Statistical analyses of the data collected permitted verification that the cervical esophagus-esophageal anastomoses done by only the extramucosal suture showed an incidence of 13.6% fistula and 30% stenosis at the level of the suture zone, which was significantly lower as compared to that observed in the two plane suture repair group where the percentages were 26.7 and 63.4 respectively. The healing of the structure of the esophageal wall at the level of the anastomosis was also significantly improved in the single plane extramucosal anastomosis group as compared to the two plane suture group. The observed results permitted conclusion that the extramucosal anastomosis in a single plane is more effícacious than that executed in two suture planes.

  14. Biocomposites from co-polypropylene and distillers' grains

    Science.gov (United States)

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

    2015-05-01

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

  15. [Investigation of adhesive properties of polypropylene net prosthesis "ESPERA"].

    Science.gov (United States)

    Belochkina, I V; Sandomirski?, B P; Furmanov, Iu A; Savitskaia, I M

    2014-12-01

    Adhesive towards the cells properties of three polypropylene net prostheses (PNP), manufactured by "Espera", with the slots size 1 x 1 mm, 2 x 2 mm, 2 x 4 mm and one specimen (the slot diameter 1 mm) on the oxycellulose background, were tested for prognostication of hernioplasty results, using nonresorbable PNP. The adhesion degree and peculiarities of cellular line, obtained from embryonal kidney of pig, put on the tested nets specimen in conditions of cultivation during 5 - 10 days were estimated, using inverted microscope in regime of phasic contrast. The data obtained witness the lowered cellular adhesion towards PNP "Espera" without oxycellular background. The net processing, using components of extracellular matrix, as well as presence of the oxycellulose fragments, facilitate the PNP ingrowth by connective tissue. PMID:25842889

  16. 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

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

    DEFF Research Database (Denmark)

    Plackett, David; Chengzhi, Chuai

    2001-01-01

    Conifer fibers were used to reinforce polypropylene (PP). To improve the compatibility between the conifer fibers and the PP matrix, the fibers were either grafted with maleated PP (MAPP), treated by adding MAPP, or mixed with ethylene/propylene/diene terpolymer (EPDM). The treatments resulted in improved processing, as well as improvements in the thermal and mechanical properties of the resultant composites compared with the composites filled with untreated conifer fibers. Moreover, MAPP grafting and MAPP treating displayed more obvious benefits than EPDM treating in terms of thermal properties, processing flowability, and tensile strength improvements. EPDM treating also produced more significant benefits than either MAPP grafting or MAPP treating in terms of impact strength and tensile elongation improvements. These improvements were attributed to surface coating of the fibers when EPDM was used. In addition, the effect of the concentration of the conifer fibers on the properties of the composites and the difference between MAPP grafting and MAPP treating were evaluated.

  18. Polypropylene grafted with glycidyl methacrylate using supercritical CO2 medium

    Scientific Electronic Library Online (English)

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

    2006-06-01

    Full Text Available Films of polypropylene (PP) were grafted with glycidil methacrylate (GMA) using supercritical CO2 as swelling agent and solvent. Different pressures and temperatures were used to study their effects on the soaking and grafting process. FTIR results showed signals at 1726 and 1640 cm-1, assigned to C [...] =O and C=C (after the soaking process), and a decreased signal at 1640 cm-1 (after the grafting procedure), suggesting the effective grafting of GMA. For the grafted material immersed in ethylenediamine, peaks in the 3600 to 3250 cm-1 range (N-H stretching) were evident. Contact angle measurements showed an increasingly hydrophilic nature in the direction from pure PP to grafted PP/GMA (PP-g-GMA) to PP-g-GMA immersed in ethylenediamine (PP-g-GMA/En). X-ray photoelectron spectroscopy provided evidenced of the effective incorporation of ethylenediamine in the grafted material.

  19. 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.

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

    DEFF Research Database (Denmark)

    Calaon, Matteo; Tosello, Guido

    2012-01-01

    In today´s industry, applications involving surface patterning of sub-?m to nanometer scale structures have shown a high growth potential. To investigate the injection molding capability of replicating sub-?m surface texture on a large scale area, a 30x80 mm2 tool insert with surface structures having a diameter of 500 nm was employed. The tool insert surface was produced using chemical-based-batch techniques such aluminum anodization and nickel electroplating. During the injection molding process, polypropylene (PP) was employed as material and packing phase parameters (packing time, packing pressure) were investigated. The replicated surface topographies were quantitatively characterized by atomic force microscopy using specific three-dimensional surface parameters and qualitatively inspected by scanning electron microscopy. Results showed that the degree of replication from the tool to the polymer part was mainly influenced by packing pressure level and distance from the gate.

  1. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-15

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

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

    Science.gov (United States)

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

    2008-08-01

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

  4. Reinforcing effect of nanosilica on polypropylene-nylon fibre composite

    International Nuclear Information System (INIS)

    Polymer composites reinforced by both the micro and nano fillers is the subject of this paper. Polypropylene (PP)-nylon micro-fibre composites modified with nanosilica and modified nanosilica (using silane coupling agent) were prepared by melt compounding. The nanosilica prepared in the laboratory was used as reinforcing filler in PP-nylon fibre composites. The compounding characteristics and mechanical properties of the composites were studied. The equilibrium torque during compounding increased with the addition of nanosilica and modified nanosilica. The use of two types of fillers leads to synergistic effect on the mechanical properties of the composite. Composites with 1 wt.% nanosilica and 30 wt.% nylon fibre show high tensile strength, tensile modulus, flexural strength and flexural modulus. Composites modified with 1 wt.% nanosilica and 10 wt.% nylon fibre-PP composite show higher impact strength.

  5. Simulating the Oxidation of Polypropylene Using a Reactive Forcefield

    Science.gov (United States)

    Budzien, Joanne; Thompson, Aidan

    2007-03-01

    Oxidation of organic materials is a problem for seals and membranes in many environments. Any particular instance of a chemical reaction is fast with purely local effects. Over longer times, the cumulative effect of many reactions results in large changes in average stress, strain, and other macroscopic properties of the sample. We have had some success in developing constitutive models for rubber, which connect the topology of the network with the observed stress during aging under strain. As the next phase of the project, we have performed simulations using a reactive forcefield to examine the atomistic changes during oxidation. Results will be presented for polypropylene and compared with experimental data for labeled samples undergoing oxidation.

  6. Evaluation of the Stability of Polypropylene toward Gamma Radiation

    International Nuclear Information System (INIS)

    Polypropylene (PP) is one of the polymers commonly employed in industry in fabrication of medical devices. However, PP tends to degrade when sterilized through gamma radiation at a dose of 25 kGy in an atmosphere containing oxygen, becoming a brittle material that could fail during its application. Therefore, the purpose of the present study was to analyze the use of different additives such as antioxidants (phenols and sterically hindered amines, BHT and Chimassorb 944, respectively), by adding them individually or as a blend into PP in order to increase its resistance to degradative effects caused by gamma radiation. Additives content varied from 0.1 to 0.8 wt.%. The effect of the radiation atmosphere (air, nitrogen) onto the polymer properties was also analyzed. The presence of carbonyl groups, decrease of the average molecular weight, abrupt increase of Melt Flow Index (MFI) and material elasticity loss with radiation clearly showed that polypropylene without any additive suffered degradation by a chain scission mechanism. Instead, addition of antioxidants, either individually or the blend of them, showed a stabilizing effect by retarding the carbonyl groups appearance, slowing down the molecular weight decrease and, in some cases, elasticity and thermal properties were maintained. Moreover, in some specific compositions, the use of a nitrogen atmosphere during the radiation process maintained MFI as well as molecular weight values under control. Finally, it can be concluded that the process of deterioration of the PP properties when exposed to gamma radiation can be retarded by the adequate use of commercial additives, and even more effectively if an inert atmosphere is employed when sterilization is performed

  7. Physical and dielectric properties of irradiated polypropylene and poly(ethylene terephthalate)

    International Nuclear Information System (INIS)

    The effect of high-energy electron irradiation in air and in nitrogen on the physical and dielectric properties of polypropylene and poly(ethylene terephthalate) has been studied by measurements of electric strength, dielectric constant, dissipation factor, tensile strength, gel fraction and molecular weight distribution. Electric strength of polypropylene was improved by irradiation, while dielectric properties of poly(ethylene terephthalate) were virtually unaffected by irradiation of 1.0-20 Mrad. Possible mechanisms for increasing electric strength are discussed from the point of view of degradation and oxidation taking place simultaneously with crosslinking of polypropylene. The maximum dose level to improve the electric strength of polypropylene is determined to be about 5 Mrad. (author)

  8. 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 ...

  9. 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.

  10. 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.

  11. 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...

  12. 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...

  13. Functionalization of PP for the enhancement of adhesion between polypropylene and polyamide multilayers

    OpenAIRE

    Rustal, Claude

    2009-01-01

    The aim of the present work was the production of a polypropylene/polyamide three-layer film without using any tie-layers. These films could find an application, for instance, in the packaging or medical industries. To promote adhesion between the two immiscible polymers, two strategies were used: addition of compatibilizers in the polypropylene (PP) matrix and direct functionalization of the PP matrix with reactive monomers such as maleic anhydride and glycidyl methacrylate. In the first...

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

    Directory of Open Access Journals (Sweden)

    François Rault

    2015-02-01

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

  15. 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.

  16. Characterization of calcium carbonate obtained from oyster and mussel shells and incorporation in polypropylene

    OpenAIRE

    Michele Regina Rosa Hamester; Palova Santos Balzer; Daniela Becker

    2012-01-01

    There is a high content of calcium carbonate in mussel and oyster shells, which can be used in the formulation of medicine, in construction or as filler in polymer materials. This work has as its main objective to obtain calcium carbonate from mussel and oyster shells and used as filler in polypropylene compared their properties with polypropylene and commercial calcium carbonate composites. The shellfish was milling and heated at 500 ºC for 2 hours. The powder obtained from shellfish were ch...

  17. 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.

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

    Scientific Electronic Library Online (English)

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

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

  19. 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.

  20. 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)

  1. 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.

  2. 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.

  3. 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.

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

    Science.gov (United States)

    Hakimi, Osnat; Chaudhury, Salma; Murphy, Richard; Carr, Andrew

    2012-04-01

    Rotator cuff tendon pathology is proposed to account for 30-70% of all shoulder pain and surgical repair with a nonabsorbable suture is the common option for painful rotator cuff tears that have failed conservative treatment. A number of studies have suggested the beneficial effect of augmenting the repair with implants constructed from polymers used for sutures. Thus, it was of interest to investigate the affinity of tendon-derived fibroblasts, often thought to be the repairing agents of torn tendons, to commonly used sutures. The aim of this comparative study was to evaluate the suitability of these sutures for the construction of a patch by measuring cell survival, proliferation, and migration of human tendon-derived fibroblasts on different sutures. To ensure relevance to the target tissue, cells used in this study were obtained from torn human supraspinatus tendons. An initial comparison of cell proliferation on suture mats showed an overall positive proliferation on polyester (Ethibond) and polydioxanone (PDSII) mats and a reduction of proliferation on vicryl (polyglactin 910) compared to day one. The results also showed that the degradation products of vicryl had a negative effect on cell growth over 10 weeks. Of the commercial sutures selected and tested, Ethibond showed the best performance in terms of cell attachment and increase in biomass. The degradable PDSII also showed good interaction with cells in vitro, but relatively poor cell adhesion. This study provides useful and clinically relevant information, which could help to guide future considerations for candidate materials from which to construct tissue repair patches. PMID:22121052

  5. VEGF-releasing suture material for enhancement of vascularization: development, in vitro and in vivo study.

    Science.gov (United States)

    Bigalke, Christian; Luderer, Frank; Wulf, Katharina; Storm, Thilo; Löbler, Marian; Arbeiter, Daniela; Rau, Bettina M; Nizze, Horst; Vollmar, Brigitte; Schmitz, Klaus-Peter; Klar, Ernst; Sternberg, Katrin

    2014-12-01

    As it has been demonstrated that bioactive substances can be delivered locally using coated surgical suture materials, the authors developed a vascular endothelial growth factor (VEGF)-releasing suture material that should promote vascularization and potentially wound healing. In this context, the study focused on the characterization of the developed suture material and the verification of its biological activity, as well as establishing a coating process that allows reproducible and stable coating of a commercially available polydioxanone suture material with poly(l-lactide) (PLLA) and 0.1?g and 1.0?g VEGF. The in vitro VEGF release kinetics was studied using a Sandwich ELISA. The biological activity of the released VEGF was investigated in vitro using human umbilical vein endothelial cells. The potential of the VEGF-releasing suture material was also studied in vivo 5days after implantation in the hind limb of Wistar rats, when the histological findings were analyzed. The essential results, enhanced cell viability in vitro as well as significantly increased vascularization in vivo, were achieved using PLLA/1.0?g VEGF-coated suture material. Furthermore, ELISA measurements revealed a high reproducibility of the VEGF release behavior. Based on the results achieved regarding the dose-effect relationship of VEGF, the stability during its processing and the release behavior, it can be predicted that a bioactive suture material would be successful in later in vivo studies. Therefore, this knowledge could be the basis for future studies, where bioactive substances with different modes of action are combined for targeted, overall enhancement of wound healing. PMID:25204522

  6. Evaluation of high-strength orthopedic sutures: a head-to-head comparison.

    Science.gov (United States)

    Miller, Timothy; Feinblatt, Jeff; Craw, John; Litsky, Alan; Flanigan, David

    2010-09-01

    The goal of this study was to determine whether a difference in cycles to failure or mode of failure would be observed among specimens of 3 high-strength suture materials, and whether different suture configurations would affect knot security. Ten representative specimens of Ethibond (Ethicon, Inc, Somerville, New Jersey), FiberWire (Arthrex, Inc, Naples, Florida), MaxBraid (Biomet, Inc, Warsaw, Indiana), and Orthocord (DePuy Orthopaedics, Warsaw, Indiana) were tied in 6 different knot configurations commonly used in orthopedic procedures. Each specimen was cyclically loaded between 9 and 180 N at a rate of 1 Hz until the specimen failed or reached a maximum of 3500 cycles. Each suture material was subjected to tensile loading until failure at a rate of 1.25 mm/s. The 3 most secure knots all included the 3 reverse half-hitch on alternating posts (3-RHAP) configuration. All specimens tied with these 3 knot types failed by suture rupture. All knots using the overhand with 3 of the same half-hitches on the same post (O-3SHSP) configuration failed by knot slippage regardless of suture material. When the 3 strongest knots were combined, FiberWire resisted a significantly greater number of fatigue cycles than Orthocord or MaxBraid. In the single load to failure tests, Orthocord, FiberWire, and MaxBraid all had significantly higher ultimate strength than Ethibond. Knots using the 3-RHAP configuration provide security superior to that of those without this configuration. All 3 high-strength sutures tested outperformed Ethibond in single load to failure testing, with FiberWire resisting the greatest number of cycles. Postoperative strength and reliability of a soft tissue repair is inherently dependent on the properties of the suture materials used. PMID:20839707

  7. 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.

  8. Técnica de suturas ajustables: Resultados Technique of adjustable sutures: Results

    Directory of Open Access Journals (Sweden)

    Lourdes R. Hernández Santos

    2001-06-01

    Full Text Available Se realizó un estudio sensorial y motor preoperatorio y posoperatorio a 84 pacientes que acudieron a la consulta de Visión Binocular con el diagnóstico de estrabismo horizontal a partir de los 13 años de edad. El método estadístico utilizado fue "t" o Chi cuadrado. Nos trazamos como objetivo determinar los resultados posoperatorios de la cirugía de estrabismo realizada con la técnica de suturas ajustables, que fueron los siguientes: el 61 % de los pacientes con exotropía y el 71,4 % con el diagnóstico de exotropía se encontraban en ortotropía a los 6 meses de la intervención. El 71,4 % de los pacientes con esotropía y el 83,3 % con el diagnóstico de esotropía se encontraban en ortotropía al año de la intervención. Esta técnica quirúrgica permite la modificación de la desviación en el posoperatorio inmediato.A preoperative and postoperative sensorial and motor study was conducted among 84 patients who received attention at the consultation room of Binocular Vision with the diagnosis of horizontal strabismus from the age of 13 years old on. The statistical method used was "t" or chi square test. Our objective was to determine the postoperative results of the strabismus surgery performed by the technique of adjustable sutures. The results were as follows: 61 % of the patients with exotropia and 71.4 % with the diagnosis of exotropia were in orthotropia 6 months after the operation. 71.4 % of the patients with exotropia and 83.3 % with the diagnosis of exotropia were in orthotropia a year after the operation. This surgical technique allows the modification of the deviation in the immediate postoperative.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-16

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

  10. Assessment of the shrinkage and ejection forces of reinforced polypropylene based on nanoclays and short glass fibre

    OpenAIRE

    Garcia, M. C. R.; Netto, A. C. S.; A. J. Pontes

    2013-01-01

    In this study the influence of nanoclay and glass fibre in the shrinkage and ejection forces in polypropylene matrix in tubular parts moulded by injection moulding were analysed. An instrumented mould was used to measure the part surface temperature and ejection forces in tubular parts. The materials used were a polypropylene homopolymer Domolen 1100L nanoclay for polyolefin nanocomposites P-802 Nanomax in percentages of 2%, 6% and 10% and a polypropylene homopolymer with conte...

  11. Nuevo método de sutura subcutánea percutánea continua / New method of continuous percutaneous subcutaneous suture

    Scientific Electronic Library Online (English)

    Germán, Brito Sosa; Reinaldo, Echevarría Romero.

    2012-06-01

    Full Text Available Objetivos: realizar un método de sutura continua, en las personas operadas en el Hospital "Julio Trigo López", que disminuya los granulomas a nivel de la herida quirúrgica, y compararlas con el método tradicional. Métodos: se realizó un estudio experimental sobre la aplicación de un método de sutura [...] subcutánea percutánea continua, en un grupo de pacientes operados de diversas enfermedades, ya sea de urgencia, electivo o ambulatorio, en el Hospital "Julio Trigo López", en los años 2008 y 2009. Resultados: con el método de sutura subcutánea percutánea continua con nylon no se forman granulomas, mientras que con el método tradicional, sí ocurre en un porcentaje no despreciable. Las ventajas del método de sutura subcutánea percutánea continua con nylon son: en el plano celular subcutáneo de la pared abdominal no queda sutura, no se producen granulomas y es más económica. Conclusiones: la sutura de nylon es menos rechazada que la del cromado, ya que no se producen granulomas. El método de sutura subcutánea percutánea continua es una sutura más hemostática que el método tradicional, ya que el por ciento de hematomas es menor. El gasto económico es menor con el método de sutura subcutánea percutánea continua. Con el método de sutura subcutánea percutánea continua la sutura es extraída al 10mo. día de haberla aplicado. Abstract in english Objectives: to apply a continuous suture method to reduce granulomas in surgical wounds in patients operated on at "Julio Trigo Lopez" hospital, and to compare the results with those of the traditional method. Methods: an experimental study was conducted on the application of a continuous percutaneo [...] us subcutaneous suture in a group of patients operated on from several diseases, either under emergency, elective or outpatient conditions at "Julio Trigo Lopez" hospital during 2008 and 2009. Results: the continuous percutaneous subcutaneous suture method with nylon prevents formation of granulomas, whereas the traditional method did show a percentage of granulomas that is not small at all. The advantages of the former are the following: there is no suture left at subcutaneous cellular level of the abdominal wall, granulomas are absent and it is a more economic option. Conclusions: the nylon suture is less rejected than the chromated suture since granulomas do not appear. The continuous percutaneous subcutaneous suture method offers a more hemostatic suture than the traditional method, being the number of hematomas lower. The economic cost is reduced and the suture may be taken out ten days after surgery.

  12. A simple technique for performing laparoscopic purse-string suturing during circular stapling anastomosis.

    Science.gov (United States)

    Takiguchi, Shuji; Sekimoto, Mitsugu; Fujiwara, Yoshiyuki; Miyata, Hiroshi; Yasuda, Takushi; Doki, Yuichiro; Yano, Masahiko; Monden, Morito

    2005-01-01

    An esophagojejunostomy using a circular stapler requires the fixing of an anvil at the esophageal stump. When this placement procedure is laparoscopically performed, purse-string suturing is difficult, and there is a risk of loosening when a conventional needle driver is used. We herein present a simple but effective technique for performing laparoscopic purse-string suturing of the esophageal stump using a semiautomatic suturing device called the Endostitch. Gastrointestinal anvil placement was laparoscopically performed for 10 patients who underwent an esophagojejunostomy following a total gastrectomy. After the lumen of the esophagus was expanded using bowel forceps, the Endostitch was used to place approximately 12 encircling purse-string sutures. An anvil was positioned with support of the esophageal wall at three points with forceps. The Endostitch was used for the ligation with a sufficient degree of tension applied by extracorporeally pulling the sutures through the abdominal wall. The time for placement of the anvil averaged approximately 8 min. The ring formation following anastomosis was favorable in all patients. As a result, we consider our technique to be simple but very effective. PMID:16175476

  13. Bioactive and mechanically strong Bioglass-poly(D,L-lactic acid) composite coatings on surgical sutures.

    Science.gov (United States)

    Chen, Q Z; Blaker, J J; Boccaccini, A R

    2006-02-01

    New coating processes have been investigated for degradable (Vicryl) and nondegradable (Mersilk) sutures with the aim to develop Bioglass coated polymer fibers for wound healing and tissue engineering scaffold applications. First, the aqueous phase of a Bioglass particle slurry was replaced with a poly(D,L-lactic acid) (PDLLA) polymer dissolved in solvent dimethyle carbonate (DMC) to act as third phase. SEM observations indicated that this alteration significantly improved the homogeneity of the coatings. Second, a new coating strategy involving two steps was developed: the sutures were first coated with a Bioglass-PDLLA composite film followed by a second PDLLA coating. This two-step process of coating has addressed the problem of poor adherence of Bioglass particles on suture surfaces. The coated sutures were knotted to determine qualitatively the mechanical integrity of the coatings. The results indicated that adhesion strength of coatings obtained by the two-step method was remarkably enhanced. A comparative assessment of the bioactivity of one-step and two-step produced coatings was carried out in vitro using acellular simulated body fluid (SBF) for up to 28 days. Coatings produced by the two-step process were found to have similar bioactivity as the one-step produced coatings. The novel Bioglass/PDLLA/Vicryl and Bioglass/PDLLA/Mersilk composite sutures are promising bioactive materials for wound healing and tissue engineering applications. PMID:16161126

  14. Vascular anomalies, sutures and small canals of the temporal bone on axial CT

    Energy Technology Data Exchange (ETDEWEB)

    Koesling, Sabrina [Department of Diagnostic Radiology, University of Halle, E. Grube Str. 40, 06097 Halle (Germany)]. E-mail: sabrina.koesling@medizin.uni-halle.de; Kunkel, Petra [Department of Diagnostic Radiology, University of Leipzig (Germany); Schul, Thomas [Department of Diagnostic Radiology, University of Leipzig (Germany)

    2005-06-01

    Purpose: Subtle bony structures, small canals and fine sutures cause sometimes problems in the analysis of CTs of the temporal bone. The aim of this study was: to analyze the visibility of subtle structures and to estimate the incidence of vascular anomalies. Patients and method: We retrospectively analyzed axial scans of 223 high-resolution CTs of the temporal bone obtained as single slice or spiral CT with 1 mm slice thickness. All CTs had clinical indications. Two experienced radiologists studied CTs regarding the visibility of the fine sutures, fissures and small canals and the occurrence of vascular anomalies. Results: The following structures were seen commonly: sphenosquamosal suture (76%), arcuate artery canal (93%), vestibular aqueduct (89%), mastoid emissary vein (82%), singular canal (56%). Not so commonly were observed: tympanosquamosal suture (31%), mastoid canaliculus (28%), lateral sigmoid sinus (28%), petrotympanic fissure (24%), tympanomastoid suture (10%). Seldom we identified: the inferior tympanic canaliculus (6%), high jugular bulb (6%), anterior sigmoid sinus (5%), dehiscent internal carotid artery canal (2%), persistent petrosquamosal sinus (1%), dehiscent jugular bulb (1%). Persistent stapedial artery, aberrant internal carotid artery, dehiscent jugular bulb, high jugular bulb with diverticulum, anterior and dehiscent sigmoid sinus were detected in below 1% of the analyzed temporal bones. The frequency of asymmetry of the jugular foramen, which varied between 3% and 42%, depended on different criterions of size. Conclusion: A profound knowledge of normal anatomy and anomalies of the temporal bone avoids misinterpretation as pathological lesions and iatrogenic bleedings.

  15. LED phototherapy on midpalatal suture after rapid maxilla expansion: a Raman spectroscopic study

    Science.gov (United States)

    Rosa, Cristiane B.; Habib, Fernando Antonio L.; de Araújo, Telma M.; dos Santos, Jean N.; Cangussu, Maria Cristina T.; Barbosa, Artur Felipe S.; de Castro, Isabele Cardoso V.; Soares, Luiz Guilherme P.; Pinheiro, Antonio L. B.

    2015-03-01

    A quick bone formation after maxillary expansion would reduce treatment timeand the biomodulating effects of LED light could contribute for it. The aim of this study was to analyze the effect of LED phototherapy on the acceleration of bone formation at the midpalatal suture after maxilla expansion. Thirty rats divided into 6 groups were used on the study at 2 time points - 7 days: Control; Expansion; and Expansion + LED; and 14 days: Expansion; Expansion + LED in the first week; Expansion and LED in the first and second weeks. LED irradiation occurred at every 48 h during 2 weeks. Expansion was accomplished using a spatula and maintained with a triple helicoid of 0.020" stainless steel orthodontic wire. A LED light (?850 ± 10nm, 150mW ± 10mW, spot of 0.5cm2, t=120 sec, SAEF of 18J/cm2) was applied in one point in the midpalatal suture immediately behind the upper incisors. Near infrared Raman spectroscopic analysis of the suture region was carried and data submitted to statistical analyzes (p?0.05). Raman spectrum analysis demonstrated that irradiation increased hydroxyapatite in the midpalatal suture after expansion. The results of this indicate that LED irradiation; have a positive biomodulation contributing to the acceleration of bone formation in the midpalatal suture after expansion procedure.

  16. 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.

  17. Post operation recurrence of inguinal hernia in children and its relation with suture material

    Directory of Open Access Journals (Sweden)

    Omid Amanollahi

    2011-09-01

    Full Text Available Background: Using non-absorbable suture in children hernia repair to decrease of recurrence is recommended in the most pediatric surgery centers. The aim of this study was to determine relationship between kind of suture material and rate of hernia recurrence. Methods: In this clinical trial 200 children (age 1-5 years with inguinal hernia who operated in Imam-Reza Hospital (kermanshah –Iran Between April 2007 until April 2008 enrolled into the study. Cases were selected by convenience sampling method and then randomly divided into two groups (100 cases per group and operated with absorbable (silk 3-0 and non-absorbable (vicryli 3-0 suture material. Following period was 12 months after operation and collected data analyzed by statistical software. Emergency operations were excluded from the study.Results: 83% of patients were boy and 17% were girl. %53 showed right side inguinal, 29% left side and %18 were bilateral hernia. After one year follow up only one case of recurrence was observed in each group.Conclusion: Our study confirmed that recurrence of inguinal hernia in children after surgery, is not related to kind of suture material (absorbability and we didn’t find any significant difference. Other factors than suture material may influence recurrence rate of hernia operation in children.

  18. The Influence of Drawing on Molecular Mobility in Polypropylene Fibers

    International Nuclear Information System (INIS)

    The influence of drawing at a certain temperature on molecular mobility of polypropylene (PP) fibers has been studied by means of broad-line nuclear magnetic resonance (NMR). Both, drawing and temperature of drawing influence physical properties of PP fibers. NMR technique is shown to be advantageous for study of these changes on molecular level since the shape of broad-line NMR spectra and processes of the NMR relaxation depend on the spatial configuration and motion of the resonating nuclei. Our measurements were performed on the sets of polypropylene fibers made from isotactic PP marked as Tatren 430 produced in Slovakia. Fibers were drawn at the temperatures Td = 293 K and 373 K to draw ratio ? from 1 to 5.5. The NMR measurements were carried out on spectrometer RYa - 2301 in the temperature range 200 - 400 K at the resonance frequency f0 = 14.1 MHz. The samples were prepared from fibers densely wounded on a thin teflon rod in the form of small solenoid. The axis of solenoid was perpendicular to external magnetic field. NMR spectra have been analysed by means of modified Bergmann's method on assumption that each spectrum measured at a given temperature may be expressed as a sum of three elementary spectra y(x) = wnyn(x, Bm, ?L) + wmym(x, ?mL, ?mG) + wbyb(x, s) (1) in which x B - B0 is a difference between the applied magnetic field induction B and the resonance magnetic field B0, Bm is the amplitude of modulating magnetic field. The narrowest spectral component yn, corresponding to the chains with highest mobility, is the Lorentzian function influenced by modulation field. The middle component ym, corresponding to the chains with hindered mobility, is the product of the Lorentzian and Gaussian functions. The broad component yb, representing rigid (immobile) chains of crystalline and highly oriented non crystalline regions, is an experimental NMR spectrum measured at the lowest temperature - 200 K in our case. The weight factors wn, wm, wb determine the relative number of the macromolecular chains in the three above mentioned phases, differing in their structure and chain's mobility. The weight factors fulfil the condition wn + wm + wb = 1. Parameters ?L, ?mL, ?mG and s determine the widths of corresponding elementary spectra. The decomposition of the NMR spectrum has been realized by fitting the experimental spectra according to equation (1) by the least square method. The temperature dependences of the wi (i = n, m, b) indicate that drawing of PP fibers and temperature of drawing influence molecular mobility of PP chains in the temperature region corresponding to the ?-relaxation. (author)

  19. 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.

  20. Novel High Efficient Coatings for Anti-Microbial Surgical Sutures Using Chlorhexidine in Fatty Acid Slow-Release Carrier Systems

    Science.gov (United States)

    Obermeier, Andreas; Schneider, Jochen; Wehner, Steffen; Matl, Florian Dominik; Schieker, Matthias; von Eisenhart-Rothe, Rüdiger; Stemberger, Axel; Burgkart, Rainer

    2014-01-01

    Sutures can cause challenging surgical site infections, due to capillary effects resulting in bacteria permeating wounds. Anti-microbial sutures may avoid these complications by inhibiting bacterial pathogens. Recently, first triclosan-resistances were reported and therefore alternative substances are becoming clinically relevant. As triclosan alternative chlorhexidine, the “gold standard” in oral antiseptics was used. The aim of the study was to optimize novel slow release chlorhexidine coatings based on fatty acids in surgical sutures, to reach a high anti-microbial efficacy and simultaneously high biocompatibility. Sutures were coated with chlorhexidine laurate and chlorhexidine palmitate solutions leading to 11, 22 or 33 µg/cm drug concentration per length. Drug release profiles were determined in aqueous elutions. Antibacterial efficacy against Staphylococcus aureus was assessed in agar diffusion tests. Biocompatibility was evaluated via established cytotoxicity assay (WST-1). A commercially triclosan-containing suture (Vicryl Plus), was used as anti-microbial reference. All coated sutures fulfilled European Pharmacopoeia required tensile strength and proved continuous slow drug release over 96 hours without complete wash out of the coated drug. High anti-microbial efficacy for up to 5 days was observed. Regarding biocompatibility, sutures using 11 µg/cm drug content displayed acceptable cytotoxic levels according to ISO 10993-5. The highest potential for human application were shown by the 11 µg/cm chlorhexidine coated sutures with palmitic acid. These novel coated sutures might be alternatives to already established anti-microbial sutures such as Vicryl Plus in case of triclosan-resistance. Chlorhexidine is already an established oral antiseptic, safety and efficacy should be proven for clinical applications in anti-microbial sutures. PMID:24983633

  1. Tectonics of the South Anyui suture: present day version

    Science.gov (United States)

    Sokolov, S. D.; Bondarenko, G. Y.; Layer, P. W.

    2004-12-01

    The South Anyui Suture (SAS) is one of the most prominent tectonic elements of North-East Asia separating the Verkhoyansk-Kolyma and Anyui-Chukotka fold belts. Following the Seslavinsky (1979), Parfenov (1984), and Natal'in (1984) the SAS is recognized as result of late Mesozoic collision between Siberia and North America continents. Many aspects of the SAS geology and evolution remain poorly understood: (i) the timing of the oceanic basin in-ception and existence; (ii) the inner structure and deformational history; (iii) the age and genesis of the ophiolites; (iv) the island-arc units distribution and age. Main results of our research in the SAS are: (1) The north vergent thrust structure is recog-nized. The autochthone includes shelf and slope sequences of the Chukotka microcontinent. The allochthone thrust package consists of ophiolitic, metamorphic, terrigenous, and island-arc rocks; (2) Late Mesozoic subduction related chaotic and intra oceanic island arc units are recognized; (3) A Bathonian-Callovian age of basalt-chert oceanic assemblages, previously reported as Late Jurassic to Neocomian; (4) A new 40Ar/39Ar data for: (i) Vurguveem ophio-litic gabbro 312.2 ± 11.1 Ià, (ii) diabase dike from Aluchin ophiolite 226.6 ± 10.5 Ià, (iii) amphibolites in the metamorphic sole of Uyamkanda ophiolite 239.1 ± 3.8 Ià, (iv) green-schists at the base of tectonic sheet 156.5 ± 3.9, 120.6 ± 3.5, 115.2 ± 1.3, 108.4 ± 1.2, and 104.1 ± 2.8 Ià. According new data tectonic evolution of SAS can be suggested the following: (1) Anyui oceanic basin existed from Mississippian to Neocomian; (2) Northern (present-day coordi-nates) margin of ocean was passive, and southern margin was active; (3) Oceanic spreading was stopped in Oxfordian, probably simultaneously with start of Canada basin opening (Grantz et al. 1998); (4) The collision accompanied by subduction of Chukotka passive mar-gin beneath the Siberia active margin; (5) Pre-collisional deformations was related with sub-duction; (6) Collisional deformations during Hauterivian to Aptian include two phases: early - thrust fault related and late - strike-slip fault related; (7) Post-collisional Albian to Senoma-nian deformations was produced by extensional event. Supported by RFBR (grant 02-05-64217), FCP "Integratsiya" (grant 0382).

  2. Arthroscopic 4-Point Suture Fixation of Anterior Cruciate Ligament Tibial Avulsion Fractures

    Science.gov (United States)

    Boutsiadis, Achilleas; Karataglis, Dimitrios; Agathangelidis, Filon; Ditsios, Konstantinos; Papadopoulos, Pericles

    2014-01-01

    Tibial eminence avulsion fractures are rare injuries occurring mainly in adolescents and young adults. When necessary, regardless of patient age, anatomic reduction and stable internal fixation are mandatory for fracture healing and accurate restoration of normal knee biomechanics. Various arthroscopically assisted fixation methods with sutures, anchors, wires, or screws have been described but can be technically demanding, thus elongating operative times. The purpose of this article is to present a technical variation of arthroscopic suture fixation of anterior cruciate ligament avulsion fractures. Using thoracic drain needles over 2.4-mm anterior cruciate ligament tibial guidewires, we recommend the safe and easy creation of four 2.9-mm tibial tunnels at different angles and at specific points. This technique uses thoracic drain needles as suture passage cannulas and offers 4-point fixation stability, avoiding potential complications of bony bridge fracture and tunnel connection. PMID:25685674

  3. 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.

  4. 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.

  5. Emergency treatment of a ruptured huge omphalocele by simple suture of its membrane

    Directory of Open Access Journals (Sweden)

    Akakpo-Numado Gamedzi

    2012-02-01

    Full Text Available Abstract Background The rupture of a huge omphalocele is an emergency that threatens the newborn baby's life. It constitutes a therapeutical concern in the absence of prosthesis especially in developing countries. Methods We are reporting herein the case of a newborn baby that we managed in emergency successfully thanks to a simple treatment. Results It was a huge omphalocele, ruptured during delivery, in a male newborn baby. We conducted a simple and conservative surgical treatment without prosthesis, which consisted of reconstruction of the omphalocele's membrane by closing it with absorbable suture materials. The suture of the omphalocele's membrane was followed by treatment with the Grob's method. This treatment saved the newborn baby's life. The total skinning was obtained after 3 months. Conclusions In case of rupture of huge omphalocele in absence of prosthesis, it is better to suture the membrane, and continue the treatment according to the Grob's method; the residual disembowelment can be repaired later.

  6. Application of Self-retaining Bidirectional Barbed Absorbable Suture in Retroperito- neoscopic Partial Nephrectomy

    Scientific Electronic Library Online (English)

    Wang, Ke; Zhang, Yu-Lian; Lin, Chun-Hua; Liu, Dong-Fu; Men, Chang-Ping; Wang, Jian-Ming; Gao, Zhen-Li.

    2014-04-01

    Full Text Available ObjectiveTo investigate the safety and feasibility of self-retaining bidirectional barbed absorbable suture application in retroperitoneoscopic partial nephrectomy.Materials and MethodsFrom Sep 2011 and Aug 2012, 76 cases of retroperitoneoscopic partial nephrectomy were performed at our hospital. Th [...] e patients were divided into two groups: self-retaining barbed suture (SRBS) group (n = 36) and non-SRBS group (n = 40). There was no significant difference in age, sex, tumor size and location between the two groups. Clinical data and outcomes were analyzed retrospectively.ResultsAll 76 cases of retroperitoneoscopic partial nephrectomy were successfully performed, without conversion to open surgery or serious intraoperative complications. In the SRBS group, the suture time, warm ischemia time and operation blood loss were significantly shorter than that of non-SRBS group (p

  7. 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

  8. 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 ?, ?, and ? 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 ?-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).

  9. Polypropylene Biocomposites with Boron Nitride and Nanohydroxyapatite Reinforcements

    Directory of Open Access Journals (Sweden)

    Kai Wang Chan

    2015-03-01

    Full Text Available In this study, we develop binary polypropylene (PP composites with hexagonal boron nitride (hBN nanoplatelets and ternary hybrids reinforced with hBN and nanohydroxyapatite (nHA. Filler hybridization is a sound approach to make novel nanocomposites with useful biological and mechanical properties. Tensile test, osteoblastic cell culture and dimethyl thiazolyl diphenyl tetrazolium (MTT assay were employed to investigate the mechanical performance, bioactivity and biocompatibility of binary PP/hBN and ternary PP/hBN-nHA composites. The purpose is to prepare biocomposite nanomaterials with good mechanical properties and biocompatibility for replacing conventional polymer composites reinforced with large hydroxyapatite microparticles at a high loading of 40 vol%. Tensile test reveals that the elastic modulus of PP composites increases, while tensile elongation decreases with increasing hBN content. Hybridization of hBN with nHA further enhances elastic modulus of PP. The cell culture and MTT assay show that osteoblastic cells attach and proliferate on binary PP/hBN and ternary PP/hBN-20%nHA nanocomposites.

  10. The effect of nucleating agent on radiation stability of polypropylene

    International Nuclear Information System (INIS)

    The radiation stability of polypropylene (PP) with and without nucleating agent (NA) is compared in relation to radiation sterilization of medical devices. In both cases high-and-low-molecular weight PP, the addition of NA increased the transparency and peak crystallization temperature of the PP. On the other hand, in poly(propylene-co-06%ethylene) copolymer, the addition of NA did not improve the transparency but crystallization occurred at higher temperature. Thus, adding NA to PP and copolymer give the advantage of shorter moulding time in the production of medical devices. It is found that both PP and copolymer with NA are less stable during irradiation and during storage after irradiation than without NA, this being the case especially for the lower molecular weight PP. The higher transparency and peak crystallization temperature in the PP and CP with NA were found to be due to smaller spherulites. As the effect of irradiation on polymer, addition of NA induce reduction of radiation stability of polymer owing to the change in morphology. (Author)

  11. 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 ? = 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.

  12. 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

  13. Radiation-induced grafting of styrene on polypropylene pellets

    International Nuclear Information System (INIS)

    The changes of radiation-induced in polypropylene (PP) pellets exposed to gamma irradiation in inert atmosphere were investigated in correlation with the applied doses (10 and 50 kGy). Also, results from the grafting of styrene onto PP pellets using simultaneous irradiation at the same doses are presented. The grafting reaction was carried out using toluene as solvent, under nitrogen atmosphere and at room temperature. The properties of the irradiated and grafted PP pellets were studied using Melt Flow Index, thermal analysis (TG and DSC), and ATR-IR. The degree of grafting (DOG) for the grafted pellets was gravimetrically determined. The results showed that radiation-induced graft polymerization on pellets were successfully obtained and the influence of dose irradiated did not change the thermal properties in spite of the increase in the MFI and consequently this increase in the viscosity results an decrease the molecular mass. The MFI for grafted pellets was not achievable because the high degree of viscosity of polymer, even arising the test temperature, the polymer was not flow enough. (author)

  14. 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 various synthesis conditions on the graft content was studied. It was found that benzene, CCl4 and petroleum ether are more effective than other solvents, the percent grafting reached 7.1% for benzene. The percent grafting is higher when graft copolymerization is carried out in argon atmosphere than those in air. For all the grafting copolymerization carried out in benzene and CCl4, percent grafting increase linearly from 1 to 5 Mrad and beyond 5 Mrad, a tendency to level off appeared. At a constant dose, the percent grafting was found to be higher at high dose rate until 228 rad/s. Percent grafting also increased continuously with increasing monomer concentration up to 2.85 mol/L, but significant increase in grafting was observed only up to 1.14 mol/L

  15. Synthesis and rheological behavior of atactic polypropylene molecular bottlebrushes

    Science.gov (United States)

    Dalsin, Samuel; Bates, Frank; Hillmyer, Marc

    2014-03-01

    Molecular bottlebrushes are branched polymer structures characterized by an extremely high density of polymeric side chains emanating from a central backbone. Due to unique conformational and rheological properties, molecular bottlebrushes have become attractive candidates for developing new photonic bandgap materials, nanotubes and nanowires, and rheological modifiers. In this study, bottlebrushes comprised of atactic polypropylene (aPP) side chains were synthesized via ring-opening metathesis polymerization of norbornenyl-terminated aPP macromonomers. A series of bottlebrush polymers with fixed side chain length and variable backbone length was prepared using Grubbs' third-generation catalyst, yielding products with low dispersity in less than five minutes reaction time. Small-amplitude oscillatory shear measurements were performed to examine linear viscoelastic properties. Master curves of all bottlebrush polymers exhibited relaxation spectra devoid of any entanglement plateau, despite high molecular weights (up to 892 kg/mol). Lack of entanglement was further confirmed by zero shear viscosity experiments, which displayed a nearly linear dependence on molecular weight. These rheological properties are compared directly with a linear aPP control sample. Supported by ExxonMobil Chemical Company.

  16. Mechanical properties of polypropylene/calcium carbonate nanocomposites

    Directory of Open Access Journals (Sweden)

    Daniel Eiras

    2009-01-01

    Full Text Available The aim of this work was to study the influence of calcium carbonate nanoparticles in both tensile and impact mechanical properties of a polypropylene homopolymer. Four compositions of PP/CaCO3 nanocomposites were prepared in a co-rotational twin screw extruder machine with calcium carbonate content of 3, 5, 7 and 10 wt. (% The tests included SEM analyzes together with EDS analyzer and FTIR spectroscopy for calcium carbonate, tensile and impact tests for PP and the nanocomposites. The results showed an increase in PP elastic modulus and a little increase in yield stress. Brittle-to-ductile transition temperature was reduced and the impact resistance increased with the addition of nanoparticles. From the stress-strain curves we determined the occurrence of debonding process before yielding leading to stress softening. Debonding stress was determined from stress-strain curves corresponding to stress in 1% strain. We concluded that the tensile properties depend on the surface contact area of nanoparticles and on their dispersion. Finally we believe that the toughening was due to the formation of diffuse shear because of debonding process.

  17. Mechanical properties of polypropylene/calcium carbonate nanocomposites

    Scientific Electronic Library Online (English)

    Daniel, Eiras; Luiz Antonio, Pessan.

    Full Text Available The aim of this work was to study the influence of calcium carbonate nanoparticles in both tensile and impact mechanical properties of a polypropylene homopolymer. Four compositions of PP/CaCO3 nanocomposites were prepared in a co-rotational twin screw extruder machine with calcium carbonate content [...] of 3, 5, 7 and 10 wt. (%) The tests included SEM analyzes together with EDS analyzer and FTIR spectroscopy for calcium carbonate, tensile and impact tests for PP and the nanocomposites. The results showed an increase in PP elastic modulus and a little increase in yield stress. Brittle-to-ductile transition temperature was reduced and the impact resistance increased with the addition of nanoparticles. From the stress-strain curves we determined the occurrence of debonding process before yielding leading to stress softening. Debonding stress was determined from stress-strain curves corresponding to stress in 1% strain. We concluded that the tensile properties depend on the surface contact area of nanoparticles and on their dispersion. Finally we believe that the toughening was due to the formation of diffuse shear because of debonding process.

  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. 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.

  19. Anticoagulant and antimicrobial finishing of non-woven polypropylene textiles.

    Science.gov (United States)

    Degoutin, S; Jimenez, M; Casetta, M; Bellayer, S; Chai, F; Blanchemain, N; Neut, C; Kacem, I; Traisnel, M; Martel, B

    2012-06-01

    The aim of this work is to prepare non-woven polypropylene (PP) textile functionalized with bioactive molecules in order to improve its anticoagulation and antibacterial properties. This paper describes the optimization of the grafting process of acrylic acid (AA) on low-pressure cold-plasma pre-activated PP, the characterization of the modified substrates and the effect of these modifications on the in vitro biological response towards cells. Then, the immobilization of gentamicin (aminoglycoside antibiotic) and heparin (anticoagulation agent) has been carried out on the grafted samples by either ionic interactions or covalent linkages. Their bioactivity has been investigated and related to the nature of their interactions with the substrate. For gentamicin-immobilized AA-grafted samples, an inhibition radius and a reduction of 99% of the adhesion of Escherichia coli have been observed when gentamicin was linked by ionic interactions, allowing the release of the antibiotic. By contrast, for heparin-immobilized AA-grafted PP samples, a strong increase of the anticoagulant effect up to 35 min has been highlighted when heparin was covalently bonded on the substrate, by contact with the blood drop. PMID:22358304

  20. Anticoagulant and antimicrobial finishing of non-woven polypropylene textiles

    International Nuclear Information System (INIS)

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

  1. Synergistic effects of sepiolite on intumescent flame retardant polypropylene

    Directory of Open Access Journals (Sweden)

    2010-12-01

    Full Text Available In this paper, the effects of sepiolite as a synergistic agent on the flame retardancy of intumescent flame retardant polypropylene (PP/IFR were studied using the limiting oxygen index (LOI, the UL-94 test, thermogravimetric analysis (TGA, laser Raman spectroscopy (LRS, cone calorimeter test (CCT and scanning electron microscopy (SEM, and the IFR system mainly consisted of the ammonium polyphosphate modified with ?-aminopropyltriethoxysilane coupling agent, melamine and dipentaerythritol. The results from the LOI and UL 94 tests show that sepiolite added to the PP/IFR system has a synergistic flame retardant effects with the IFR system. The TGA results reveal that sepiolite enhances the thermal stability of the PP/IFR composite and increases the char residue formation. The cone calorimeter results indicate that the heat release rate, mass loss rate, total heat release and average specific extinction area of the PP/IFR/sepiolite composite decrease in comparison with the PP/IFR composite. The LRS measurements provide useful information on the carbonaceous microstructures. The morphological structures observed by SEM have demonstrated that sepiolite promote the formation of the reinforced and homogeneous char barrier on the surface of the composites. Simultaneously, the Young’s modulus and flexural modulus of the PP/IFR composites are also much better improved with the increase of sepiolite added.

  2. 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.

  3. Organo-modified montmorillonite reinforced walnut shell/polypropylene composites

    International Nuclear Information System (INIS)

    Highlights: • Walnut shells as a bio-waste resource have been used in polypropylene composites. • The effects of OMMT and MAPP content on some properties of composites investigated. • OMMT and MAPP have significant effects on mechanical properties of the composites. • With increasing OMMT content, significant decreasing in water absorption occurred. - Abstract: This article presents the preparation and characterization of walnut shell/PP composites and compares with wood flour/PP composites. The effects of organo-montmorillonite (OMMT, 0, 3 and 5 wt.%) as reinforcing agent and MAPP as coupling agent (4 and 6 wt.%) on the mechanical and physical properties were also investigated. Composites manufactured via melt compounding and subsequent hot press. The resulting composites had acceptable and comparable properties to wood flour properties and the highest improvement of mechanical properties was achieved at 3% organo-clay loading and 6% MAPP. Morphologies of the nanocomposites were analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM study approved the good interaction of the walnut shell flour with the polymer as well as effectiveness of organo-clay in improvement of the interaction. TEM study revealed better dispersion of silicate layers in polymer–matrix composites (PMCs) loaded with 3 wt.% of clay

  4. Functional behaviour of polypropylene/ZnO-soluble starch nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Chandramouleeswaran, Subramani [Department of Paint and Polymer Engineering and Technology, University Institute of Chemical Technology, Adenwala Road, Matunga, Mumbai-400 019 (India); Mhaske, S T [Department of Paint and Polymer Engineering and Technology, University Institute of Chemical Technology, Adenwala Road, Matunga, Mumbai-400 019 (India); Kathe, A A [Nanotechnology Research Group, Central Institute for Research on Cotton Technology, Adenwala Road, Matunga, Mumbai-400 019 (India); Varadarajan, P V [Nanotechnology Research Group, Central Institute for Research on Cotton Technology, Adenwala Road, Matunga, Mumbai-400 019 (India); Prasad, Virendra [Nanotechnology Research Group, Central Institute for Research on Cotton Technology, Adenwala Road, Matunga, Mumbai-400 019 (India); Vigneshwaran, Nadanathangam [Nanotechnology Research Group, Central Institute for Research on Cotton Technology, Adenwala Road, Matunga, Mumbai-400 019 (India)

    2007-09-26

    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.

  5. 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.

  6. Effect of isotacticity on radiation stability of polypropylene

    International Nuclear Information System (INIS)

    The relationship between radiation stability and isotacticity of polypropylene(PP), such as isotactic pentad ratio, was studied in this paper. It was found that the higher isotacticity, the better radiation stability. Compared with normal PP powder which has normal isotacticity, the special PP powder with higher isotacticity, such as, isotactic pentad ratio > 98%, can keep the Melting Index change less than normal PP after UV-light-oxygen aging or ?-irradiation in air. Furthermore, the special PP powder with higher isotacticity has lower intention of crosslinking or branching after 1KGy ?-irradiation in vacuum and has lower intention of degradation after 5KGy ?-irradiation in vacuum. The special PP powder with higher isotacticity also has lower content of carbonyl after 25KGy ?-irradiation in air. These demonstrated that the special PP with higher isotacticity made from 'special catalyst' is more suitable as the material for radiation sterilization than normal PP, because there are less 'week points' in PP with higher isotacticity than that in PP with lower isotacticity. The random copolymer with 2.7% ethylene units made from the 'special catalyst' mentioned above is even more stable in irradiation sterilization than homopolypropylene with higher isotacticity; therefore, it is reasonable that a random copolypropylene with about 4%wt ethylene made from the 'special catalyst' should be the much more suitable PP material than normal PP for irradiation sterilization. (author)

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

    Directory of Open Access Journals (Sweden)

    Lotti Cybele

    2000-01-01

    Full Text Available The effect of incorporating (C2-C8 ethylene-octene elastomer on the mechanical properties and morphology of polypropylene copolymers has been investigated employing two types of PP copolymer, with and without nucleating agent. The results were compared to the ones presented by a commercial PP heterophase (reactor impact modified PP/EPR. The addition of the elastomer increases the toughness of the blends but reduces their stiffness. PP blends in the low elastomer content region (< 20% show low values of the Izod impact strength and both, elastomer content and impact strength, are directly proportional to the area under the beta damping peak or its maximum intensity of the elastomer. The morphology is a continuous pattern of segregate elastomeric particles with average particle size in the range of 0.27 mum to 0.39 mum. The average particle size and particle size distribution plotted in log-normal distribution curves, increases slightly with the increase in the elastomer content. The reactor modified PP heterophase has a broader particle size distribution and an average particle size of 0.56 mum, at the lower limit but inside the range for good impact performance, as observed.

  8. Leyla loop: a time-saving suture technique for robotic atrial closure

    OpenAIRE

    K?l?ç, Leyla; ?enay, ?ahin; Ümit Güllü, A.; 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...

  9. The role of biological adhesive and suture material on rabbit hepatic injury

    OpenAIRE

    Taha Murched Omar; De Rosa Karen; Fagundes Djalma José

    2006-01-01

    PURPOSE: To evaluate the performance of fibrin adhesive and absorbable suture thread in the repairing of hepatic injures in rabbits. METHODS: New Zealand albino rabbits (n=16), males and females, from 5 to 6 months old, average weight of 2500 g, were distributed randomly in Group A (n-8) - biological adhesive and Group B (n=8) - suture thread. After anesthesia with acepromazine (1mg/Kg), ketamine (50mg/Kg) and fentanyl EV (0,5ml/Kg), it was performed a supra-umbilical median laparotomy, the m...

  10. Suture Granuloma Showing False-Positive Findings on FDG-PET

    OpenAIRE

    Kohei Takahara; Hiroaki Kakinoki; Saya Ikoma; Kazuma Udo; Shohei Tobu; Yuji Satoh(Institute of Physics, University of Tsukuba, Ibaraki 305-8571, Japan); Yuji Tokuda; Mitsuru Noguchi; Shigehisa Aoki; Jiro Uozumi

    2013-01-01

    We report a case of a 33-year-old male with a mixed germ-cell testicular tumor. Postoperative follow-up FDG-PET revealed concentration of FDG in the left inguinal area which is not tumor metastasis or local recurrence but suture reactivity granuloma. In this paper, we reviewed suture granulomas associated with false-positive findings on FDG-PET after surgery. If FDG-PET will be used more frequently in the future, it will be necessary to refrain from using silk thread in order to prevent any u...

  11. Randomised controlled study of two different techniques of skin suture in endoscopic release of carpal tunnel

    DEFF Research Database (Denmark)

    Hansen, Torben Bæk; Kirkeby, Lone

    2009-01-01

    In a prospective, randomised trial of 54 hands in 47 patients incisions were randomised to be closed by either absorbable subcuticular (polyglytone 6211, Caprosyn), or non-absorbable interrupted (polybutester, Novafil), sutures after single-portal endoscopic release of the carpal tunnel. There was a significant reduction in pain scores on days 1 and 2 in the patients treated with an absorbable continuous subcuticular suture, and no difference in inflammation or infection. There was no difference in the cosmetic appearance between the two groups after three months.

  12. [Current status and perspectives of mechanical suture techniques in abdominal and thoracic surgery].

    Science.gov (United States)

    Kockel, N; Ulrich, B

    1991-01-01

    In surgery the application of mechanical suture techniques is increasing. In order to inform the surgeons in detail about the different surgical stapling instruments being available today, the mechanical suture devices are listed in this article. These instruments can be divided into linear staplers, circular and linear anastomosis staplers, ligating clips and skin and fascia staplers. Own experiences with stapling instruments, their advantages and disadvantages as well as the different forms of application are described. Further information is given on the increasing use of absorbable staples and of new anastomosis techniques, i.e. instruments creating an anastomosis on the principle of compression. PMID:2042415

  13. 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.

  14. 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

    Scientific Electronic Library Online (English)

    José Guilherme, Minossi; Carlos Antonio, Caramori; Celso Vieira de Souza, Leite; Luiz Eduardo, Naresse.

    2010-10-01

    Full Text Available 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 (M2)e 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" . Abstract in english 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 th [...] rough 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.

  15. 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 ?-radiation on the structural and mechanical properties of the composition systems tested. The magnitude of the adsorbed dose od ?-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)

  16. Constitutive modeling of the viscoelastic and viscoplastic responses of metallocene catalyzed polypropylene

    DEFF Research Database (Denmark)

    Drozdov, Aleksey; Christiansen, Jesper de Claville

    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 – Three series of experiments are conducted where the mechanical response of mPP is analyzed in tensile tests with various strain rates, relaxation tests with various strains, and creep tests with various stresses at room temperature. A constitutive model is derived for semicrystalline polymers under an 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 long-term creep tests. Keywords Metallocene catalyzed polypropylene, Viscoelasticity, Viscoplasticity, Creep rupture, Constitutive modeling, Elastoplastic analysis, Viscosity, Creep, Physical properties of materials Paper type Research paper

  17. Polypropylene Production Optimization in Fluidized Bed Catalytic Reactor (FBCR: Statistical Modeling and Pilot Scale Experimental Validation

    Directory of Open Access Journals (Sweden)

    Mohammad Jakir Hossain Khan

    2014-03-01

    Full Text Available Propylene is one type of plastic that is widely used in our everyday life. This study focuses on the identification and justification of the optimum process parameters for polypropylene production in a novel pilot plant based fluidized bed reactor. This first-of-its-kind statistical modeling with experimental validation for the process parameters of polypropylene production was conducted by applying ANNOVA (Analysis of variance method to Response Surface Methodology (RSM. Three important process variables i.e., reaction temperature, system pressure and hydrogen percentage were considered as the important input factors for the polypropylene production in the analysis performed. In order to examine the effect of process parameters and their interactions, the ANOVA method was utilized among a range of other statistical diagnostic tools such as the correlation between actual and predicted values, the residuals and predicted response, outlier t plot, 3D response surface and contour analysis plots. The statistical analysis showed that the proposed quadratic model had a good fit with the experimental results. At optimum conditions with temperature of 75 °C, system pressure of 25 bar and hydrogen percentage of 2%, the highest polypropylene production obtained is 5.82% per pass. Hence it is concluded that the developed experimental design and proposed model can be successfully employed with over a 95% confidence level for optimum polypropylene production in a fluidized bed catalytic reactor (FBCR.

  18. 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.

  19. 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, anterior–posterior (AP) knee laxity and the tensile properties of the repaired ligament were measure...

  20. Surgical-site infection after abdominal wall closure with triclosan-impregnated polydioxanone sutures: results of a randomized clinical pathway facilitated trial (NCT00998907).

    OpenAIRE

    Justinger, Christoph; Slotta, Jan Erik; Ningel, Sebastian; Gräber, Stefan; Kollmar, Otto; Schilling, Martin Karl

    2013-01-01

    BACKGROUND: Wound infections after abdominal surgery are still frequent types of nosocomial infections. Suture materials might serve as a vehicle for mechanical transport of bacteria into the surgical wound. To prevent the contamination of suture material in surgical wounds, triclosan-coated suture materials with antibacterial activity was developed. We here report a prospective randomized pathway controlled trial investigating the effect of triclosan impregnation of polydioxanone sutures use...

  1. Polypropylene/Layered Double Hydroxide (LDH) Nanocomposites: Influence of LDH Particle Size on the Crystallization Behavior of Polypropylene.

    Science.gov (United States)

    Nagendra, Baku; Mohan, Kiran; Gowd, E Bhoje

    2015-06-17

    Highly dispersed isotactic polypropylene (iPP) nanocomposites were prepared by incorporating two different sized Mg-Al LDH nanoparticles with different loadings from 1 to 10 wt % using a modified solvent mixing method. Larger sized LDH nanoparticles (?3-4 ?m) were prepared from the gel form of Mg-Al LDH, and the smaller sized nanoparticles (?50-200 nm) were prepared by sonication of as-synthesized LDH particles. Such obtained LDH nanoparticles were carefully characterized using wide-angle X-ray diffraction (WAXD), transmission electron microscopy, and scanning electron microscopy. WAXD and atomic force microscopy results indicate that the LDH nanoparticles were highly dispersed in the iPP matrix. The influence of LDH nanoparticles size and concentration on the thermal stability, spherulitic morphology, melting behavior, isothermal crystallization kinetics, and lamellar structure of iPP were investigated. Incorporation of low loadings of sonicated LDH particles (e.g., 1-2.5 wt %) show substantial effect on thermal stability, spherulite size, crystallinity, and crystallization half-time and lamellar morphology of iPP compared to the pure iPP and that of nanocomposites with larger LDH particles with same loadings. The better nucleation ability of iPP in the presence of sonicated LDH can be attributed to the high surface area of LDH nanoparticles along with its better dispersibility within the polymer matrix. The incorporation of LDH nanoparticles does not change the crystallization growth mechanism and crystal structure of iPP. PMID:25741910

  2. The Yarlung Zangbo Suture Zone Ophiolites, Tibet: A Synthesis

    Science.gov (United States)

    Hebert, R.; Guilmette, C.; Dupuis, C.; Dubois-Cote, V.; Huot, F.; Dostal, J.; Wang, C.; Li, Y.

    2006-12-01

    This paper presents the main results of a research project focused on the Yarlung Zangbo Suture Zone (YZSZ) ophiolites and related mélanges and flysch. Study area is representing a 300 km long and 30 km wide segment. The Cretaceous ophiolites are remnants of Neo-Tethys basin which was almost totally consumed in a northward oriented subduction zone and southerly transported onto the Indian plate colliding with Eurasia circa 50 Ma ago. The ophiolite massifs rest on an ophiolitic mélange, containing locally 124-127 Ma garnet- bearing and garnet-free foliated amphibolites. These amphibolites experienced high-temperature and relatively high pressure suggesting they were generated because of initiation of an intraoceanic subduction zone. Further south a Triasic flysch and a Cretaceous mélange contain igneous blocks derived from partial reworking of Indian passive margin and Tethyan ocean-floor. The amphibolites show arc tholeiitic affinities such La/Sm 0.8 and negative Ta and Nb anomalies and are geochemically similar to the ophiolitic mafic units. The mafic blocks found in the flysch and mélange zones are of intra-continental and intra-oceanic geochemical affinities respectively. The ophiolites are made of cpx-harzburgitic mantle and thin gabbro-lacking crust. Mantle harzburgites are subdivided into two groups. Samples from the western massifs are characterized by porphyroclastic textures, aluminous spinels (Cr/(Cr+Al) : 0.13-0.21), low average TiO2 content (0.04 wt.%), depleted REE patterns (average La/Sm ratios 0.4) and derive from 7-12 % melting of N-MORB-like source. Samples from the eastern massifs are granular peridotites with Cr-rich spinels (Cr/(Cr+Al) : 0.33-0.74), very low average TiO2 content (0.008 wt. %), enriched REE patterns (average La/Sm 5.6) and could originate from 20-30 % partial melting of a depleted source further enriched by an episode of metasomatism. Crustal samples are mainly basaltic flows, diabasic and rare gabbroic intrusions. They are subdivided into two groups. The western group is made of pl-cpx-phyric arc tholeiites with depleted REE patterns (average La/Sm 0.6) and slight Ta-Nb negative anomalies. The eastern group is made up of pl-cpx-(am)-phyric arc tholeiites having fractionated REE patterns (average La/Sm 4.6) and strong Ta-Nb negative anomalies. Boninitic component increases towards the east and is prominent in Luobusa area. These results are consistent with derivation of the ophiolites from dismemberment of back-arc (western portion) and intra-oceanic arc (eastern portion) sectors of the Neo-Tethys marginal basin.

  3. The Uterine Sandwich Method for Placenta Previa Accreta in Mullerian Anomaly: Combining the B-Lynch Compression Suture and an Intrauterine Gauze Tampon

    OpenAIRE

    Mustafa Kaplano?lu

    2013-01-01

    Mullerian duct anomalies may cause obstetric complications, such as postpartum hemorrhage (PPH) and placental adhesion anomalies. Uterine compression suture may be useful for controlling PPH (especially atony). In recent studies, uterine compression sutures have been used in placenta accreta. We report a case of PPH, a placenta accreta accompanying a large septae, treated with B-Lynch suture and intrauterine gauze tampon.

  4. Flammability of polypropylene/organoclay nanocomposites; Inflamabilidade de nanocompositos de polipropileno/argila organofilica

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Tatianny Soares; Barbosa, Renata, E-mail: tsaeng3@yahoo.com.br [Universidade Federal do Piaui (UFPI), Teresina (Brazil); Carvalho, Laura Hecker de [Universidade Federal de Campina Grande (UFCG), PB (Brazil); Canedo, Eduardo Luis [Instituto de Tecnologia de Pernambuco, Recife (Brazil)

    2014-11-01

    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)

  5. Controlled synthesis of stereoblock polypropylene. New trends in the development of elastomers

    International Nuclear Information System (INIS)

    The review generalises published data on the synthesis of elastomeric stereoblock polypropylene, a representative of thermoelastoplastics, which are prepared by random or block copolymerisation of various co-monomers and are widely used in the manufacture of diverse mechanical rubber goods. New unique applications of metallocene and post-metallocene catalysts in the design of polyolefin elastomers with a broad spectrum of physicomechanical characteristics are discussed. Particular attention is given to modern homogeneous catalyst systems based on Group IVB element metallocene complexes, which ensure highly efficient synthesis of polypropylene elastomers with various stereoblock structures. Data on the specific features of the structure and properties of the elastomeric stereoblock polypropylene are analysed. The bibliography includes 160 references.

  6. Morphological, viscoelastic and mechanical characterization of polypropylene/exfoliated graphite nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Creusa Iara; Oliveira, Ricardo Vinicius Bof de; Mauler, Raquel Santos, E-mail: raquel.mauler@ufrgs.br [Universidade Federal do Rio Grande do Sul (PGCIMAT/IQ/UFRGS), Porto Alegre, RS (Brazil); Bianchi, Otavio [Universidade de Caxias do Sul (PGMAT/CCET/UCS), RS (Brazil); Oviedo, Mauro Alfredo Soto [Braskem S/A, Rio de Janeiro, RJ (Brazil)

    2013-07-01

    The viscoelastic, mechanical and morphological properties of polypropylene/exfoliated graphite nanocomposites with different contents of nanofiller were investigated. According to transmission electron microscopy results, the nanofiller particles were homogeneously dispersed in the matrix. The rheological properties indicated that incorporation of graphite improved the matrix stiffness and had a reinforcing effect. Exfoliated graphite had a weak interaction with the polypropylene. The behavior of the nanocomposites was similar to that of polypropylene in terms of the interfacial detachment inferred from the transmission electron microscopy images and of their G' (storage) and G' (loss) moduli, and viscosity. The mechanical properties of the nanocomposites compared to the matrix improved significantly for the flexural and storage moduli with little loss of impact strength. (author)

  7. Essential work of fracture analysis for starch filled poly(propylene carbonate) composites

    International Nuclear Information System (INIS)

    Starch filled poly(propylene carbonate) composites are environmental friendly materials. In this study, the fracture toughness of composites under mode I loading was determined by the essential work of fracture concept. The specific essential fracture work of the poly(propylene carbonate)/starch composites decreases with increasing the starch content, while the non-essential work term, ?w p increases with increasing the starch content. In addition, the morphologies, thermal properties, thermo-mechanical properties were studied by scanning electron microscope, thermogravimetric analysis, dynamic mechanical analysis, and differential scanning calorimetry, respectively. The thermal and thermo-mechanical measurements revealed that increasing starch content led to an increase in glass transition temperature and thermal stability. Morphology observation indicates that poly(propylene carbonate) and starch have weak interfacial adhesion

  8. Estimation of radiation dose rate in new polypropylene strainer in primary heat transport system

    International Nuclear Information System (INIS)

    Heavy water is used in Primary Heat Transport system at Dhruva research reactor. It contains suspended and ionic impurities, therefore it is required to purify heavy water for removal of impurities and to maintain grade of heavy water. For enhancing performance of purification system testing of new polypropylene filters is planned for removal of suspended impurities at flow rate of 400 lit/min. Physical properties of polypropylene changes after exposure to radiation after radiation dose of 1.0E+05 Gy it becomes brittle. Calculations of beta and gamma radiation dose rate are based on the activity of radionuclides present in heavy water used as main coolant system. Assessment of service life of new filters is carried out by calculating the radiation dose rate to polypropylene filters during in service and radiation dose rate of existing removed stainless steel strainer. (author)

  9. Morphological, viscoelastic and mechanical characterization of polypropylene/exfoliated graphite nanocomposites

    Scientific Electronic Library Online (English)

    Creusa Iara, Ferreira; Otavio, Bianchi; Mauro Alfredo Soto, Oviedo; Ricardo Vinicius Bof de, Oliveira; Raquel Santos, Mauler.

    Full Text Available The viscoelastic, mechanical and morphological properties of polypropylene/exfoliated graphite nanocomposites with different contents of nanofiller were investigated. According to transmission electron microscopy results, the nanofiller particles were homogeneously dispersed in the matrix. The rheol [...] ogical properties indicated that incorporation of graphite improved the matrix stiffness and had a reinforcing effect. Exfoliated graphite had a weak interaction with the polypropylene. The behavior of the nanocomposites was similar to that of polypropylene in terms of the interfacial detachment inferred from the transmission electron microscopy images and of their G' (storage) and G'' (loss) moduli, and viscosity. The mechanical properties of the nanocomposites compared to the matrix improved significantly for the flexural and storage moduli with little loss of impact strength.

  10. Study of microcellular injection-molded polypropylene/waste ground rubber tire powder blend

    International Nuclear Information System (INIS)

    Microcellular polypropylene/waste ground rubber tire powder blend processing was performed on an injection-molding machine with a chemical foaming agent. The molded samples produced based on the design of experiments (DOE) matrices were subjected to tensile testing and scanning electron microscope (SEM) analyses. Molding conditions and waste ground rubber tire (WGRT) powder have been found to have profound effects on the cell structures and mechanical properties of polypropylene (PP) and waste ground rubber tire powder composite samples. The result shows that microcellular PP/WGRT blend samples exhibit smaller cell size and higher cell density compare with polypropylene resin. Among the molding parameters studied, chemical foaming agent weight percentage has the most significant effect on cell size, cell density, and tensile strength. The results also suggest that tensile strength of microcellular PP/WGRT composites is sensitive to weight reduction, and skin thickness.

  11. Photocatalytic degradation of polypropylene/TiO2 nano-composites

    Scientific Electronic Library Online (English)

    Mohammad Mehdi, Kamrannejad; Amin, Hasanzadeh; Nasim, Nosoudi; Lee, Mai; Ali Akbar, Babaluo.

    2014-08-01

    Full Text Available In this research, we have investigated the photocatalytic degradation of carbon-coated TiO2 nanoparticles in polypropylene-based nano-composites. For this purpose, polypropylene-based nano-composites were prepared using carbon-coated TiO2 nanoparticles and commercially available TiO2 nanoparticles ( [...] Degussa, P25). Our results from SEM, FTIR, and tensile tests showed that the photocatalytic property of TiO2 causes chain scission reactions, crosslinking and consequently photocatalytic degradation of polypropylene that affects the mechanical properties of exposed nano-composites. We have observed that with greater carbon content of the TiO2 nano-powders, there is less photocatalytic degradation.

  12. Effect of low doses beta irradiation on thermal, micro and macro mechanical properties of irradiated polypropylene

    Science.gov (United States)

    Manas, David; Manas, Miroslav; Chvatalova, Lenka; Stanek, Michal; Bednarik, Martin; Mizera, Ales

    2014-09-01

    The influence of beta radiation on the change of structure and selected properties (both mechanical and heat properties) of polymer materials has been proved. Medium and high doses of beta radiation influence both macro-mechanical and thermal properties of polypropylene in a positive as well as negative way. The use of low doses of beta radiation for polypropylene and its influence on the changes of micro, macro mechanical and thermal properties was thoroughly studied. The specimen were produced by injection technology and subjected to low doses of beta radiation of 0, 15 and 33 kGy The changes of structure, micro, macro and thermal mechanical properties were evaluated by FTIR, WAXS, DSC, tensile test, impact test, microhardness test and thermomechanical analysis. The results of measurements showed a considerable improvement (threefold) of micro mechanical properties (microhardness) of low beta radiation doses. It was also proved that macro and thermomechanical properties of polypropylene modified by low beta radiation doses improved.

  13. CO-PYROLYSIS OF POLYPROPYLENE WITH PETROLEUM OF BACIA DE CAMPOS

    Directory of Open Access Journals (Sweden)

    DE ASSUMPÇÃO, Luiz Carlos Fonte Nova; MARQUES, Mônica Regina da Costa; CARBONELL, Montserrat Motas

    2009-01-01

    Full Text Available In this study, the process of co-pyrolysis of polypropylene (PP residues with gas-oil was evaluated, varying thetemperature and the amount of polypropylene fed to the reactor. The polypropylene samples and gas-oil weresubmitted to the thermal co-pyrolysis in an inert atmosphere, varying the temperature and the amount of PP.The influence of the gas-oil was evaluated carrying the co-pyrolysis in the absence of PP. The pyrolysed liquidsproduced by this thermal treatment were characterized by modified gaseous chromatography in order toevaluate the yield in the range of distillation of diesel. As a result, the increase of PP amount lead to a reductionin the yield of the pyrolytic liquid and to an increase of the amount of solid generated. The effect of temperatureincrease showed an inverse result. The results show that plastic residue co-pyrolysys is a potential method forchemical recycling of plastic products.

  14. Comparison of in-out and overnight catheterization in post operative urinary retention

    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. Comparative Study on Mechanical Properties between Pure and Recycled Polypropylenes

    Directory of Open Access Journals (Sweden)

    Ariadne L. Juwono

    2010-04-01

    Full Text Available Polypropylene (PP is one type of thermoplastics that is widely used in our daily activities. A combination of the high demand and the easiness of recycling process, the recycled PP has been generally applied. In this study, the structure and the mechanical properties of the as-received PPs, recycled PPs, and commercial recycled PPs were compared, especially for cloth hanger application. DSC test results showed that recycling process did not cause a significant change to the material's melting point, which stayed in a range of 160-163 oC. Meanwhile, FTIR test results showed that the commercial recycled PPs contained of Polyethylene (PE, which was not found in the as-received and the recycled PPs. Tensile and hardness tests demonstrated that there were no significant differences between the as-received and recycled PPs. In contrast, tensile test results of the commercial recycled PPs showed that the tensile strength, Young modulus and strain-at-break were lower than those of the as-received PPs by 22.1%, 8.1% and 65.7% respectively. The hardness test results of the commercial recycled PPs showed that the recycling process had a little effect on the material's hardness. These facts were supported by SEM observation on the surface that the contour of the commercial recycled PPs was relatively flatter and had smaller grain size than those of the as-received PPs. This indicated that the commercial recycled PPs were more brittle compared to the recycled PPs. To conclude, the recycled PPs have similar properties to the as-received PPs so that recycled PPs are suitable to be applied as cloth hanger application.

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

    DEFF Research Database (Denmark)

    Jankova Atanasova, Katja; Daugaard, Anders Egede

    With the aim of creating tough nanocomposits (NC) [1] based on polypropylene (PP) and nanoclay (NCl) in the framework of the 7th EU program NANOTOUGH we have designed amphiphilic block copolymers utilizing Atom Transfer Radical Polymerization (ATRP) [2]. They consist of a hydrophobic block of Kraton L-1203 from Kuraray Co., Japan with molecular weight 7000 and PDI=1.05, and a hydrophilic block of quaternized dimethylaminoethyl methacrylate (DMAEMA). The size of the hydrophilic block was varied, which increasingly caused better dispersibility of the block copolymer in water. This was essential for the exchange of the Na+ ions of the used NCl (3.8 wt.-% aq. dispersion of montmorillonite, MMT from Laviosa Chimica Mineralia, Italy) by the synthesized charged block copolymer, which was performed in water. Modified nanoclays with 2.5 to 8.0 wt.-% of the quaternized PEB-b-PDMAEMA35 were prepared. The exfoliation and intercalation was studied by XRD. Rheological measurements of either aq. solutions of the charged block copolymers or PP master batches with various amounts of the modified MMT were performed. Tensile tests of NCs show similar behaivor, but SAXS reveals change in the nanostructure. According to the structural data derived from SAXS [4] the MMT acts like a nucleating agent to the PP that starts competitive nucleation of crystallites in the PP during manufacturing. Consequently, the PP crystallites in the composites are small and imperfect. This means that the self-reinforcement of the PP (by its crystallites) is replaced by alien-reinforcement (of the MMT). Furthermore, the results from the impact strength and cyclic test of the prepared PP nanocomposites [3] are promicing.

  17. Suture-related urolithiasis following repair of inadvertent prostatectomy in a dog.

    Science.gov (United States)

    Puttick, Jennifer L; Sereda, Colin W

    2012-07-01

    A 10-month-old male chow chow mixed breed dog was presented for anuria secondary to inadvertent prostatectomy performed during unilateral cryptorchidectomy. Surgical repair was successfully performed; however, this resulted in suture-associated urolith formation 3 months later, requiring a second surgical intervention and urethrostomy. PMID:23277648

  18. External approach to in vivo force measurement on mitral valve traction suture

    DEFF Research Database (Denmark)

    Jensen, Morten O; Jensen, Henrik; Langhoff Honge, Jesper; Nygaard, Hans; Hasenkam, Michael; Nielsen, Sten L

    2012-01-01

    Force measurements on the mitral valve apparatus have been reported from in vivo and in vitro studies. Recent reparative techniques for ischemic mitral valve insufficiency call for papillary muscle relocation. This study describes a device to measure forces generated on traction sutures utilized for this purpose.

  19. Suture-related urolithiasis following repair of inadvertent prostatectomy in a dog

    OpenAIRE

    Puttick, Jennifer L.; Sereda, Colin W.

    2012-01-01

    A 10-month-old male chow chow mixed breed dog was presented for anuria secondary to inadvertent prostatectomy performed during unilateral cryptorchidectomy. Surgical repair was successfully performed; however, this resulted in suture-associated urolith formation 3 months later, requiring a second surgical intervention and urethrostomy.

  20. Effects of force magnitude on a sutural model: a quantitative approach

    International Nuclear Information System (INIS)

    In an effort to quantify the biologic effects of an orthodontic tensile force, the rat interpremaxillary suture was investigated as a model for the periodontal ligament and expanded in vivo with a helical spring across the maxillary incisors. Three levels of force were used: light (50 to 75 g), medium (150 to 175 g), and heavy (250 to 300 g). Thymidine labeling and histologic studies after 12 hours and 1, 2, and 4 days of force delivery are described (n = 48 rats), as are biochemical studies after 2 and 4 days including a 6-hour organ culture (n = 32). The percentage of labeled cells increased significantly in all force groups at 1 day, followed by a rapid decline at 2 days, to a value at 4 days not significantly different from the controls. Biochemical studies showed significant increases in proline incorporation and alkaline phosphatase activity after 2 days of heavy force application. Histologic examinations showed obvious tissue changes beginning by day 1 and involving increases in suture width, vascularity, size and number of cells, amount of osteoid production, and changes in suture morphology. The experimental system was convenient, inflammation-free, and appeared to be reliable as evidenced by characteristic, synchronous tissue and autoradiographic changes in all experimental sutures through 4 days

  1. PASSEQ 2006-2008: Passive Seismic Experiment in Trans-Europe Suture ZoneI.

    Czech Academy of Sciences Publication Activity Database

    Wilde-Piórko, M.; Geissler, W.H.; Plomerová, Jaroslava; Grad, M.; Babuška, Vladislav; Brückl, E.; Cyziene, J.; Czuba, W.; England, R.; Gaczy?ski, E.; Gaždová, Renata; Gregersen, S.; Guterch, A.; Hanka, W.; Hegedüs, E.; Heuer, B.; Jedli?ka, Petr; Lazauskiene, J.; Keller, G. R.; Kind, R.; Klinge, K.; Kolínský, Petr; Komminaho, K.; Kozlovskaya, E.; Krüger, F.; Larsen, T.; Majda?ski, M.; Málek, Ji?í; Motuza, G.; Novotný, Old?ich; Pietrasiak, R.; Plenefisch, T.; R?žek, Bohuslav; Sliaupa, S.; ?roda, P.; ?wieczak, M.; Tiira, T.; Voss, P.; Wiejacz, P.

    2008-01-01

    Ro?. 52, ?. 3 (2008), s. 439-448. ISSN 0039-3169 R&D Projects: GA AV ?R IAA300120709 Institutional research plan: CEZ:AV0Z30120515; CEZ:AV0Z30460519 Keywords : lithosphere-asthenosphere system * Trans-European Suture Zone * Teisseyre-Tornquist Zone Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.770, year: 2008

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

    DEFF Research Database (Denmark)

    Jorgensen, L N; Sommer, ThorbjØrn

    2013-01-01

    BACKGROUND: Many patients develop discomfort after open repair of a groin hernia. It was hypothesized that suture fixation of the mesh is a cause of these symptoms. METHODS: This patient- and assessor-blinded randomized multicentre clinical trial compared a self-gripping mesh (Parietene Progrip(®) ) and sutured mesh for open primary repair of uncomplicated inguinal hernia by the Lichtenstein technique. Patients were assessed before surgery, on the day of operation, and at 1 and 12 months after surgery. The primary endpoint was moderate or severe symptoms after 12 months, including a combination of chronic pain, numbness and discomfort. RESULTS: The intention-to-treat population comprised 163 patients with self-gripping mesh and 171 with sutured mesh. The 12-month prevalence of moderate or severe symptoms was 17·4 and 20·2 per cent respectively (P = 0·573). There were no significant 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 symptoms after inguinal hernia repair. Registration number: NCT00815698 (http://www.clinicaltrials.gov). Copyright © 2012 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

  3. The cosmetic outcome of the scar formation after cesarean section : percutaneous or intracutaneous suture?

    DEFF Research Database (Denmark)

    Lindholt, Jes Sanddal; Möller-Christensen, T

    1994-01-01

    Three methods of skin closure after cesarean section were tested and compared in a prospective trial. Eighty-nine (82.5%) appeared for follow-up investigation 4-5 months after delivery. The mean scar width was significantly narrower after phannenstiel incision compared with percutaneous nylon sutures after lower midline incision, 3.1 mm versus 11.3 mm. Intracutaneous continuous PDS-suture after lower midline incision produced scars 40% narrower than with percutaneous sutures, 6.8 versus 11.3 mm. 37.5% of the women sutured intracutaneously complained over persistent secretion after discharge from the hospital. Some of these complaints were probably due to the introduction of new materials and skin closure technique. None consulted a physician with their complaints, i.e. the complications were sub-clinical. Exclusion of the women with persistent secretions from the material led to significantly narrower scars compared with percutaneous closure, 4.5 versus 11.1. Thus, even better results can be expected as experience with the technique increases. Observer and patient satisfaction with the cosmetic outcome were measured independently on a 'Lasa-line'. Their opinions coincided; the order of acceptability was worst with percutaneous wound closure after lower midline incision, next best with intracutaneous closure after lower midline incision, and best after phannenstiel incision with intracutaneous closure.

  4. 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

  5. Model for suturing of Superior and Churchill plates: An example of double indentation tectonics

    Science.gov (United States)

    Gibb, R. A.

    1983-07-01

    Recent gravity surveys in eastern and southern Hudson Bay, Canada, have revealed, for the first time, the gravity anomaly pattern over the complete length of the proposed circum-Superior suture. A symmetrical distribution of linear, positive anomalies near the southern and eastern perimeters of Hudson Bay suggests a model in which suturing of Superior and Churchill protoplates was accomplished by subduction of oceanic lithosphere and by progressive double indentation of the rigid-plastic Churchill craton by the Thompson and Ungava salients of the rigid Superior protocontinent. Suturing was initiated at the Thompson salient with extrusion of Churchill material laterally along strike-slip faults into the Hudson Bay embayment. With continued subduction, indentation of the Churchill craton by the Ungava salient commenced, so that Churchill material was now extruded from two directions to fill the embayment of Hudson Bay. Following complete suturing of the Hudson Bay embayment, the motion of the Superior plate relative to the Churchill may have changed by about 90° E to facilitate complete closure of the predecessor of the Labrador Sea. The pattern of faulting and other major structural elements of northern Saskatchewan-Manitoba can be interpreted in terms of the proposed analogue model of plane indentation. The regional faults and their senses of motion correspond generally to that predicted by the theoretical pattern of slip lines associated with a wedge-shaped indenter.

  6. Effects of force magnitude on a sutural model: a quantitative approach

    Energy Technology Data Exchange (ETDEWEB)

    Southard, K.A.; Forbes, D.P.

    1988-06-01

    In an effort to quantify the biologic effects of an orthodontic tensile force, the rat interpremaxillary suture was investigated as a model for the periodontal ligament and expanded in vivo with a helical spring across the maxillary incisors. Three levels of force were used: light (50 to 75 g), medium (150 to 175 g), and heavy (250 to 300 g). Thymidine labeling and histologic studies after 12 hours and 1, 2, and 4 days of force delivery are described (n = 48 rats), as are biochemical studies after 2 and 4 days including a 6-hour organ culture (n = 32). The percentage of labeled cells increased significantly in all force groups at 1 day, followed by a rapid decline at 2 days, to a value at 4 days not significantly different from the controls. Biochemical studies showed significant increases in proline incorporation and alkaline phosphatase activity after 2 days of heavy force application. Histologic examinations showed obvious tissue changes beginning by day 1 and involving increases in suture width, vascularity, size and number of cells, amount of osteoid production, and changes in suture morphology. The experimental system was convenient, inflammation-free, and appeared to be reliable as evidenced by characteristic, synchronous tissue and autoradiographic changes in all experimental sutures through 4 days.

  7. Radiographic changes in non-operated isolated sagittal suture synostosis; Radiologische Veraenderungen bei nichtoperierter isolierter Sagittalnahtsynostose

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, M.; Darge, K. [Abteilung fuer Paediatrische Radiologie, Institut fuer Roentgendiagnostik, Klinikum der Bayerischen Julius-Maximilians-Universitaet Wuerzburg (Germany); Collmann, H. [Abteilung fuer Paediatrische Neurochirurgie, Neurochirurgische Klinik und Poliklinik, Klinikum der Bayerischen Julius-Maximillians-Universitaet Wuerzburg (Germany)

    2007-04-15

    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.)

  8. Evaluation of four suture materials for surgical incision closure in Siberian sturgeon

    Science.gov (United States)

    Boone, S. Shaun; Hernandez, Sonia M.; Camus, Alvin C.; Peterson, Douglas C.; Jennings, Cecil A.; Shelton, James L.; Divers, Stephen J.

    2015-01-01

    The visual and microscopic tissue reactions to the absorbable monofilament Monocryl, absorbable monofilament triclosan-coated Monocryl-Plus, absorbable multifilament Vicryl, and nonabsorbable monofilament Prolene were evaluated for their use of surgical closure in Siberian Sturgeon Acipenser baerii. Postoperative assessments were conducted at 1, 2, 8, 12, and 26 and 55 weeks to visually evaluate the surgical incision for suture retention, incision healing, erythema, and swelling. Incisions were also assessed microscopically at 1, 2, and 8 weeks for necrosis, inflammation, hemorrhage, and fibroplasia. The results indicated that incisions closed with either Vicryl or Prolene suture materials were more likely to exhibit more erythema or incomplete healing compared with those closed with Monocryl or Monocryl-Plus. The surgical implantation of a transmitter in the coelomic cavity did not significantly affect the response variables among the four suture materials. Monocryl or Monocryl-Plus were equally effective and superior to other suture materials used for closing surgical incisions in Siberian Sturgeon or closely related species of sturgeon. Furthermore, Monocryl or Monocryl-Plus may decrease the risk of transmitter expulsion through the incision, as surgical wounds appear to heal faster and exhibit less erythema compared with those closed with Vicryl.

  9. 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.

  10. Avaliação de dois diferentes fios de sutura para colopexia incisional laparoscopia em cães: estudo experimental / Evaluation of two differents sutures for inciosional laparoscopic colopexy in dogs: a experimental study

    Scientific Electronic Library Online (English)

    Marcelo Veloso, Brun; Ney Luis, Pippi; Carlos Afonso de Castro, Beck; Emerson Antônio, Contesini; Rosecler Alves, Pereira; Rafael, Stedile; Adamas Tassinari, Bonfada; Ângela Ilha, Bordin; T.F., Silva; L.M., Columé; K., Gomes; A.R.P., Vieira Junior.

    2004-06-01

    Full Text Available Com o objetivo de descrever técnica laparoscópica para a realização de colopexia em cães, comparando os resultados de dois distintos fios de sutura, os autores utilizaram 10 animais separados em dois grupos de igual número (GV e GP). Nos do GV, a colopexia foi realizada com fio de poliglactina 910 3 [...] -0, enquanto no GP empregou-se polipropileno de igual espessura. Para o procedimento, os caninos foram posicionados em decúbito dorsal e submetidos a pneumoperitônio com CO2 na pressão de 12mmHg. Foram introduzidos quatro trocartes, dois de 5mm e dois de 10mm, nas regiões umbilical, lateral direita e esquerda. O cólon descendente foi apreendido com pinça Babcock e submetido a incisão seromuscular de 2,5cm na superfície antimesentérica. Procedeu-se a incisão semelhante no músculo transverso abdominal, paralelamente à linha alba. As margens correspondentes das feridas do intestino e da musculatura abdominal foram aposicionadas com suturas contínuas simples. No 14º dia pós-operatório, os caninos foram submetidos a laparoscopia para as avaliações da cavidade peritoneal e das aderências produzidas, bem como para as coletas de biópsias. Constatou-se permanência da colopexia em todos os animais e a fixação do omento na região da sutura em 60% e 100% dos representantes do GV e do GP, respectivamente. Ambos os fios demonstraram adequabilidade; contudo, a sutura foi realizada mais facilmente com a poliglactina 910, graças à sua menor "memória". Na histologia, observou-se que a deposição de tecido conjuntivo foi semelhante entre os grupos, sendo que em todos os casos o colágeno apresentava-se maturo. Pode-se concluir que a técnica laparoscópica proposta é adequada para a realização de colopexias em cães. Abstract in english Aiming to describe the laparoscopic technique for dog colopexy and to compare two suture materials 10 mongrel dogs separated in two groups of five (GV e GP). In the GV group the colopexy was realized with a polyglactin 910 3-0, and in the GP group a polypropylene 3-0 was used. For both procedures th [...] e dogs were positioned in dorsal recumbence and submitted to a pneumoperitoneum with CO2 using pressure of 12mmHg. Four trocars (two of 5mm and two of 10mm) were introduced in the left and right position of umbilical region. The descendent colon was grasped with a Babcock forceps and submitted to a seromuscular incision of 2.5 cm in the antimesenteric surface. A similar lesion was preceded in the transverse abdominal muscle, parallel with the ventral midline. The incisioned margins of colon and transverse abdominal muscle were sutured in two lines of simple continuous pattern. Fourteen days after the surgeries the dogs were submitted to laparoscopy surgery for evaluations of the peritoneal cavity and of the adherences occurred and to biopsies collections. The colopexy permanence was found in all dogs and the omentum fixation in the suture region was observed in 60% of GV dogs and 100% of GP dogs. Both suture materials were reported adequate for the colopexy procedure, however the polyglactin 910 suture was more easily realized due to its lower memory. In the histological analysis were observed that the connective tissue deposition was similar in both groups and in all 10 dogs the collagen fibers presented mature aspect. Based on the results presented herein, the proposed laparoscopic technique in adequate for colopexy procedure in dogs.

  11. Polypropylene/graphite nanocomposites by in situ polymerization; Nanocompositos polipropileno/grafite via polimerizacao in situ

    Energy Technology Data Exchange (ETDEWEB)

    Milani, Marceo A.; Galland, Giselda B., E-mail: griselda@iq.ufrgs.br [Instituto de Quimica, UFRGS, Porto Alegre, RS (Brazil); Quijada, Raul [Universidade de Chile, Santiago (Chile). Centro de Ciencias de los Materiales; Basso, Nara R.S. [Fac. de Quimica, PUCRS, Porto Alegre, RS (Brazil)

    2011-07-01

    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){sub 2}ZrCl{sub 2} or rac-Me{sub 2}Si(Ind){sub 2}ZrCl{sub 2} 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)

  12. Effects of Polypropylene Fibers on the Shear Strength of Sandy Soil

    OpenAIRE

    Adil K. Al-Tamimi; Mousa F. Attom

    2010-01-01

    This paper presents the effect of two types of polypropylene fibers on shear strength parameters of sandy soil. To achieve the goals of this research, a sandy soil was obtained from a depth of 40 cm from the natural ground surface around American University of Sharjah. Two types of polypropylene fibers; one highly flexible with flat profile and the other with relatively high stiffness and crimpled profile were used in this study with four different aspect ratios (L/D) for each type. The initi...

  13. Effects of Maleic Anhydride on the Mechanical Properties and Morphology of Wheat Straw Fibre Reinforced Polypropylene

    OpenAIRE

    Obele Chizoba M.; Ishidi Edith Y; Odera Raphael S.

    2012-01-01

    Composites made of polypropylene (PP) and wheat straw fiber (WS) as well as polypropylene/ wheat straw fiber/maleic anhydride (MA) were prepared using single screw injection moulding extruder at filler loadings 10,20,30,40 weight %. The tensile strengths recorded at maximum loading for PP/WS and PP/WS/MA are 9.5MPa and 8.1MPa respectively showing improved strength with additive of MA. The tensile modulus for the two cases was found to be 193.3MPa and 295MPa respectively. Percentage elongation...

  14. The risk analysis of dust electrostatic based on on-site survey of polypropylene plant

    International Nuclear Information System (INIS)

    The dust electrostatic explosion accidents in polypropylene plant are mainly caused by the interaction of combustible gas, dust and static electricity. This paper analyses the key parts easy to produce dust and the risks of dust electrostatic by on-site survey of polypropylene plant, and proposes corresponding safety protection measures. The analysis results indicate that any careless mistakes and deviation in every step of process control may lead to electrostatic explosion in the silo. And if the equipment has some inherent defects and there are some careless mistakes in the process control, it will be easier to cause dust electrostatic explosion accidents.

  15. Synthesis of Nanocomposite Adsorbent on the Base of Polypropylene Fabric with Copper Ferrocyanide Grains

    Directory of Open Access Journals (Sweden)

    Bondar I.V.

    2012-08-01

    Full Text Available Composite adsorbents based on polypropylene fibers with chemically bound nanopartices of copper ferrocyanide were synthesized by two-stage experiment: radiation-induced graft polymerization of acrylic acid onto non-woven polypropylene fabric followed by in-situ formation of copper ferrocyanize nanoparticles and their stabilization on the fabric surface within the grafted layer. Scanning electron microscope investigations revealed a homogeneous compact layer of copper ferrocynide nanosized aggregates (65-70 nm. The synthesized composite material was stable in the base solutions (pH ? 10.5 and exhibited high efficiency for cesium adsorption.

  16. Strength and porosity of concrete incorporating polypropylene and steel fibres subjected to high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Pliya, P.; Beaucour, A.-L.; Noumowe, A. (Laboratoire de Mecanique et Materiaux du Genie Civil, Univ. de Cergy-Pontoise (France)), e-mail: prosper.pliya@u-cergy.fr

    2009-07-01

    The aim of this study is to investigate the effect of polypropylene and steel fibres on the behaviour of concrete subjected to high temperature. Test were carried out on concrete elements subjected to four target temperatures: 150, 300, 450 and 600 deg C. Three groups of concrete were studied: one group of concrete mixes without fibre, one group of concrete mixes with polypropylene fibres and one group of concrete with steel fibres. The specimens were subjected to heating - cooling cycles from the ambient temperature to 150 deg C, 300 deg C, 450 deg C and 600 deg C

  17. Fracture Properties of Polypropylene Fiber Reinforced Concrete Containing Fly Ash and Silica Fume

    OpenAIRE

    Qingfu Li; Peng Zhang

    2013-01-01

    A parametric experimental study has been conducted to investigate the effect of polypropylene fiber on the fracture properties of concrete containing fly ash and silica fume, with five fiber volume fraction (0.04, 0.06, 0.08, 0.1 and 0.12%) used. The results indicate that the addition of polypropylene fiber has greatly improved the fracture parameters of concrete composite containing 15% fly ash and 6% silica fume, such as fracture toughness, fracture energy, effective crack length, maximum m...

  18. Structural-selective properties of nuclear filters on the basis of polypropylene

    International Nuclear Information System (INIS)

    The infrared spectroscopy method was applied to investigate polypropylene nuclear filters, irradiated by accelerated Xe-ions. It has been shown that irradiation leads to radiation and post-radiation oxidation, formation of carboxyl and hydroxyl groups and amorphization of its structure. The following treatment of this polymer by chromic acid results in forming thin surface layer (0.01 mcm) with amorphous structure. Results of investigation of structure-selective properties of nuclear filters (on the base of thin polypropylene films) irradiated by accelerated heavy ions and chemically etched - are also discussed

  19. A COMPARATIVE STUDY OF TWO SUTURE CONFIGURATIONS IN ZONE II FLEXOR TENDON REPAIR IN ADULTS

    Directory of Open Access Journals (Sweden)

    A. M. Navali

    2008-06-01

    Full Text Available Although the increase in the number of core sutures during flexor tendon repair increases the tensile strength of the repair, both increased handling at the time of repair and increased bulk at the repair site have been hypothesized as affecting clinical outcomes by increasing gliding resistance. The purpose of our study was to assess whether increasing the number of core sutures from two strands to four strands in zone II flexor tendon repair could improve the clinical results. A total of 42 patients with 60 flexor tendon lacerations in zone II were enrolled in this study. The injured tendon randomly underwent surgical repair by using one of the 2-strand or 4-strand modified Strickland techniques. Postoperative rehabilitation was the active extension-rubber band flexion method of Kleinert in all patients. The average duration of follow up was 8 months. The mean total active motion was 155.16? in 2-strand group (excluding two ruptures and 154.33? in 4-strand group (P > 0.05. Using Strickland's original score, this corresponds to excellent result in 83.3% and 86.6% of patients in 2-strand group and 4-strand group, respectively. Statistically, there was no significant difference between the clinical outcomes obtained in these groups. Concerning the tendon rupture after the repair, all of the ruptures (2 cases occurred in the 2-strand group (P > 0.05. We concluded that both suture strength and gliding resistance have influence on the result of flexor tendon repair in zone II, and increasing the number of core sutures and the resulting suture strength may be negatively affected by increase in gliding resistance.

  20. Sutura elástica para tratamento de grandes feridas Elastic sutures for the treatment of extensive wounds

    Directory of Open Access Journals (Sweden)

    Eduardo Luiz Nigri dos Santos

    2012-09-01

    Full Text Available O fechamento de grandes feridas continua sendo um importante desafio para o cirurgião plástico. O objetivo deste artigo é a divulgação da sutura elástica como uma técnica eficaz para o fechamento de grandes feridas. Foram incluídos no estudo 14 pacientes portadores de grandes lesões decorrentes de traumas diversos em membros inferiores. O fechamento completo das feridas foi obtido por procedimento dividido em duas etapas, sendo a primeira representada por aproximação das bordas opostas da ferida por meio de tiras circulares elásticas de borracha e a segunda, realizada alguns dias após, com a retirada das tiras elásticas, seguida de sutura simples com fio mononáilon. A sutura elástica demonstrou ser uma técnica segura, funcionalmente eficaz, de fácil execução e de baixo custo para fechamento de grandes feridas, evitando áreas doadoras, como nos enxertos de pele.The suture of extensive wounds remains a major challenge for plastic surgeons. The objective of this article is to promote use of elastic sutures as an effective procedure for the closure of extensive wounds. Fourteen patients presenting with extensive wounds caused by trauma in the lower limbs were included in the study. The entire wound was sutured in each patient with a two-step procedure. In the first step, the opposite edges of the wound were approximated using rubber circular elastic bands. In the second step, carried out a few days later, the elastic bands were removed, followed by a simple suture with monofilament nylon thread. Placement of elastic sutures proved to be a safe, functionally effective, easy-to-perform, and low-cost procedure for the closure of extensive wounds without using donor areas as skin grafts.

  1. Sutura elástica para tratamento de grandes feridas / Elastic sutures for the treatment of extensive wounds

    Scientific Electronic Library Online (English)

    Eduardo Luiz Nigri dos, Santos; Ricardo Araujo, Oliveira.

    2012-09-01

    Full Text Available O fechamento de grandes feridas continua sendo um importante desafio para o cirurgião plástico. O objetivo deste artigo é a divulgação da sutura elástica como uma técnica eficaz para o fechamento de grandes feridas. Foram incluídos no estudo 14 pacientes portadores de grandes lesões decorrentes de t [...] raumas diversos em membros inferiores. O fechamento completo das feridas foi obtido por procedimento dividido em duas etapas, sendo a primeira representada por aproximação das bordas opostas da ferida por meio de tiras circulares elásticas de borracha e a segunda, realizada alguns dias após, com a retirada das tiras elásticas, seguida de sutura simples com fio mononáilon. A sutura elástica demonstrou ser uma técnica segura, funcionalmente eficaz, de fácil execução e de baixo custo para fechamento de grandes feridas, evitando áreas doadoras, como nos enxertos de pele. Abstract in english The suture of extensive wounds remains a major challenge for plastic surgeons. The objective of this article is to promote use of elastic sutures as an effective procedure for the closure of extensive wounds. Fourteen patients presenting with extensive wounds caused by trauma in the lower limbs were [...] included in the study. The entire wound was sutured in each patient with a two-step procedure. In the first step, the opposite edges of the wound were approximated using rubber circular elastic bands. In the second step, carried out a few days later, the elastic bands were removed, followed by a simple suture with monofilament nylon thread. Placement of elastic sutures proved to be a safe, functionally effective, easy-to-perform, and low-cost procedure for the closure of extensive wounds without using donor areas as skin grafts.

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

    Scientific Electronic Library Online (English)

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

    2012-02-01

    Full Text Available PURPOSE: V-LocTM180 (Covidien Healthcare, Mansfield, MA) is a new unidirectional barbed suture that may reduce loss of tension during a running closure. We evaluated the use of the barbed suture for urethrovesical anastomosis (UVA) during robotic assisted laparoscopic prostatectomy (RALP). Time to c [...] ompletion of UVA, post-operative anastomotic leak rate, and urinary incontinence were compared in patients undergoing UVA with 3-0 unidirectional-barbed suture vs. 3-0 MonocrylTM (Ethicon, Somerville, NJ). MATERIALS AND METHODS: Data were prospectively collected for 70 consecutive patients undergoing RALP for prostate cancer between November 2009 and October 2010. In the first 35 patients, the UVA was performed using a modified running van Velthoven anastomosis technique using two separate 3-0 monofilament sutures. In the subsequent 35 patients, the UVA was performed using two running novel unidirectional barbed sutures. At 7-12 days postoperatively, all patients were evaluated with a cystogram to determine anastomotic integrity. Urinary incontinence was assessed at two months and five months by total daily pad usage. Clinical symptoms suggestive of bladder neck contracture were elicited. RESULTS: Age, PSA, Gleason score, prostate size, estimated blood loss, body mass index, and clinical and pathologic stage between the 2 groups were similar. Comparing the monofilament group and V-LocTM180 cohorts, average time to complete the anastomosis was similar (27.4 vs. 26.4 minutes, p = 0.73) as was the rate of urinary extravasation on cystogram (5.7 % vs. 8.6%, p = 0.65). There were no symptomatic bladder neck contractures noted at 5 months of follow-up. At 2 months, the percentage of patients using 2 or more pads per day was lower in the V-LocTM180 cohort (24% vs. 44%, p

  3. Surgery effect of endoscope-assisted transscleral suture fixation intraocular lens

    Directory of Open Access Journals (Sweden)

    Hai-Jun Yang

    2013-09-01

    Full Text Available AIM: To research surgery effect and complications of transscleral suture fixation intraocular lens(IOLassisted with endoscope or with the traditional method. METHODS: Thirty cases need IOL implantation without sufficient posterior lens capsule membrane support were chosen. These patients were divided into two groups randomly and every group had 15 patients. Group A underwent surgery of transscleral suture fixation IOL with the traditional method. Group B had surgery of transscleral suture fixation IOL assisted with endoscope. The surgical complications and postoperative effect were regularly observed and analyzed. RESULTS: All patients were successfully completed surgery. The mean naked visual acuity(NVAof group A was 0.26±0.14(from 0.1 to 0.6one month after operation. The mean NVA of group B was 0.37±0.16(from 0.15 to 0.8. The postoperative NVA of two group patients was improved different degree than preoperative NVA. The differences of postoperative NVA between the two groups had statistical significance(t=2.351, Pt=1.327, P>0.05. Group A appeared more complications included 3 cases of corneal edema, 3 cases of uveitis, 4 cases of anterior chamber hemorrhage, 2 cases of vitreous hemorrhage, 3 cases of IOL deviation or tilted, 1 case of the peripheral iris anterior adhesion, 2 cases of elevated intraocular pressure. Group B appeared only a few minor complications including 5 cases of corneal edema, 2 cases of uveitis. CONCLUSION: With the help of endoscope for transscleral suture fixation IOL can ensure sutures fixed position is located in the ciliary sulcus, surgery complications decrease significantly and surgical effect is better compared with the traditional method.

  4. The red-eared slider turtle carapace under fatigue loading: The effect of rib-suture arrangement.

    Science.gov (United States)

    Achrai, Ben; Daniel Wagner, H

    2015-08-01

    Biological structures consisting of strong boney elements interconnected by compliant but tough collagenous sutures are abundantly found in skulls and shells of, among others, armadillos, alligators, turtles and more. In the turtle shell, a unique arrangement of alternating rigid (rib) and flexible (suture) elements gives rise to superior mechanical performance when subjected to low and high strain-rate loadings. However, the resistance to repeated load cycling - fatigue - of the turtle shell has yet to be examined. Such repeated loading could approximately simulate the consecutive high-stress bending loads exerted during (a predator) biting or clawing. In the present study flexural high-stress cyclic loads were applied to rib and suture specimens, taken from the top dorsal part of the red-eared slider turtle shell, termed carapace. Subsequently, to obtain a more complete and integrated fatigue behavior of the carapace, specimens containing a complex alternating rib-suture-rib-suture-rib configuration were tested as well. Although the sutures were found to be the least resistant to repeated loads, a synergistic effect was observed for the complex specimens, displaying improved fatigue durability compared to the individual (suture or even rib) constituents. This study may assist in the design of future high-stress fatigue-resistant materials incorporating complex assemblies of rigid and flexible elements. PMID:26042699

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

    Energy Technology Data Exchange (ETDEWEB)

    Calandrelli, Rosalinda; D' Apolito, Gabriella; Gaudino, Simona; Stefanetti, Mariangela; Colosimo, Cesare [Universita Cattolica Sacro Cuore, Institute of Radiology, Rome (Italy); Massimi, Luca; Di Rocco, Concezio [Universita Cattolica Sacro Cuore, Institute of Neurosurgery, Rome (Italy)

    2014-10-15

    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.)

  6. Inhibition of secondary cartilage of the intermaxillary suture in Sprague-Dawley rats following the enucleation of maxillary molars

    International Nuclear Information System (INIS)

    A single craniofacial suture can undergo several morphologic transformations during its development. From 3 to 7 weeks of age, the intermaxillary suture of the rat is synchondrotic in character, featuring secondary cartilage; at later times, this suture is syndesmotic in character, featuring a fibrous tissue interface. Since intermittent mechanical stimulation has been reported to initiate secondary cartilage formation, a study was done to determine if the functioning dentition were responsible for secondary cartilage formation in the intermaxillary suture of the rat. Twenty-two female Sprague-Dawley rats were used. At 3 weeks of age, prior to eruption, the maxillary molars were enucleated from nine animals. Body weights were recorded weekly. Animals were sacrificed weekly from 4 to 7 weeks of age. One hour prior to sacrifice, each rat was injected with [35S]sulfate at a dosage of 2 microCi/g body weight. The tissues were evaluated by light microscopy and autoradiography. In the experimental group, the midpalatal suture did not undergo the normal synchondrotic transformation. Instead, this suture remained fibrous with negligible metachromatic staining. In the control animals, the peak period of [35S]sulfate incorporation was 4 weeks of age and was five times greater than in the experimental group. The primary stimulus for the initiation of secondary cartilage formation in the midpalatal suture of the rat was molar function. Also, functioning molars were found to be important in the maintenance of the palatal bone

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

    Directory of Open Access Journals (Sweden)

    G. N. Onyeagoro

    2013-01-01

    Full Text Available 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. %. The results show that when MAPP alone was used as compatibilizer, property improvements were not substantial due to the low reactivity between MAPP and PET, which produces insignificant amount of copolymers as coupling agent at the interfaces. Effective compatibilization was achieved by adding epoxy resin (EPR as suggested by impressive improvement in the properties investigated. Outstanding property improvements, especially oil resistance, tensile and impact strengths (higher values, and elongation at break (lower value were obtained with increases in EPR and filler loadings.

  8. Fatores de risco no tratamento de lesões do ceco com sutura primária em ratos Risk factors on the treatment of cecum injuries with primary suture in rats

    Directory of Open Access Journals (Sweden)

    Gustavo Pereira Fraga

    2004-12-01

    Full Text Available Objetivo: O presente trabalho teve como objetivo avaliar os resultados da sutura primária no tratamento das lesões traumáticas de ceco em ratos, após exposição a intervalos de tempo crescentes entre o trauma e a cirurgia, e com diferentes graus de peritonite. Métodos: Em estudo randomizado, duplo-cego, 96 ratos Wistar, machos, com peso variando de 200 a 250 gramas, foram submetidos a laparotomia, em que se realizava lesão de 5 milímetros de diâmetro na borda contramesentérica do ceco. Em 12 animais do grupo-controle realizava-se de imediato sutura primária com pontos totais, separados, com fio de polipropileno 7.0. Nos demais grupos, com 12 animais cada, a laparotomia para reparo da lesão foi realizada após intervalos de: 30 minutos, 1, 2, 4, 6, 9 e 12 horas. No momento do reparo da lesão, uma das suas bordas era ressecada e enviada para exame anatomopatológico. Foi feito controle diário no pós-operatório, atentando-se para a presença de complicações, em especial deiscência da sutura, sendo a eutanásia dos animais realizada no 1º, 4º, 7º e 14º dia de pós-operatório. Em todos animais foi realizada necropsia, atentando-se aos achados macroscópicos e microscópicos do local da sutura. Resultados: Não houve associação entre a demora para o tratamento cirúrgico da lesão e a evolução para graus mais avançados de peritonite. A mortalidade nos 14 animais com peritonite difusa foi de 100%. A mortalidade global foi de 25% (24 animais, sendo que 6 animais (25% dos óbitos morreram antes do tratamento. Nenhum dos animais tratados que evoluíram a óbito teve complicação relacionada com a sutura da lesão. Os óbitos foram precoces, decorrentes de peritonite e sepse. Entre os 72 ratos sobreviventes, observou-se deiscência da sutura em 9 animais (12,5%. A ocorrência desta complicação foi maior em animais operados a partir da sexta hora após o trauma, sendo os resultados estatisticamente significativos. A incidência de deiscência também foi maior nos ratos que apresentavam contaminação fecal mais intensa da cavidade peritoneal. A intensidade da peritonite no momento da sutura observada no exame histológico não teve associação com a ocorrência de complicações da sutura primária. Conclusão: A sutura primária é um procedimento de risco para tratar ratos, transcorrido intervalo superior a seis horas após o trauma, ou na vigência de contaminação intensa da cavidade por fezes.Purpose: Analyze the results of primary suture in the treatment of cecum traumatic injuries in rats, after the exposure to increasing time intervals between the trauma and the surgery and with different peritonitis degrees. Methods: In a randomized double-blinded study, 96 Wistar male rats, weight ranging between 200 and 250 grams, underwent laparotomy, in which a 5-milimiter-diameter-injury in the contramesenteric edge of the cecum was performed. In 12 animals of the control-group a prompt primary suture was executed, with total and separated stitches, with 7.0 polypropylene thread. In the other groups, with 12 animals each, a laparotomy for repair of the injury was executed after intervals of 30 minutes, 1, 2, 4, 6, 9 and 12 hours. At the time of injury repair, one of its edges was ressected and sent for anatomopathological examination. A daily control after the surgery was done, observing the presence of complications, specially dehiscence of the suture, and the euthanasia of the animals were done in the 1st, 4th, 7th and 14th day after the surgery. Necropsy was executed in all animals, observing the macroscopic and microscopic findings in the area of suture. Results: There was no association between the delay for surgical treatment of the injury and peritonitis degrees. The mortality in the 14 animals with diffuse peritonitis was 100%. Global mortality was 25% (24 animals, and 6 animals (25% died before treatment. None of the animals treated that evolved to death had complications related to the suture of the injury. These early deaths were due to peritonitis and sepsis. Among the

  9. Assessment of mechanical properties and dimensions of suture threads utilized in orthopedic surgeries

    Directory of Open Access Journals (Sweden)

    Sardenberg Trajano

    2003-01-01

    Full Text Available Surgical materials of monofilament nylon (0, 3-0 and 4-0, braided polyester (0, 3-0 and 4-0 and monofilament polypropylene (0, 3-0 and 4-0 of 7 trademarks commercialized in Brazil, was submitted to analysis of diameter, length, enchasement resistance, tensile strength of surgery materials knotted and unknotted, according to ABNT. The results show that most of surgical materials was inside of preconizing patterns of ABNT.

  10. Rheological characterization and modeling of linear and branched metallocene polypropylenes prepared by reactive processing.

    Czech Academy of Sciences Publication Activity Database

    Pivokonský, Radek; Zatloukal, M.; Filip, Petr; Tzoganakis, C.

    2009-01-01

    Ro?. 156, 1-2 (2009), s. 1-6. ISSN 0377-0257 R&D Projects: GA AV ?R IAA200600703 Institutional research plan: CEZ:AV0Z20600510 Keywords : Melt strength * Metallocene polypropylene * Elongational viscosity Subject RIV: BK - Fluid Dynamics Impact factor: 2.000, year: 2009

  11. Effect of tetraethoxysilane coating on the improvement of plasma treated polypropylene adhesion

    Science.gov (United States)

    Pantoja, M.; Encinas, N.; Abenojar, J.; Martínez, M. A.

    2013-09-01

    Polypropylene is one of the most used polymers due to its lightweight and recyclability properties, among others. However, its poor characteristics regarding surface energy and lack of polar functional groups have to be overcome to perform adhesion processes. The main objective of this work is to improve the adhesion behavior of polypropylene by combining atmospheric pressure plasma surface activation and silane adhesion promoter. Tetraethoxysilane hydrolysis and condensation are followed through infrared spectroscopy by attenuated total reflectance in order to set the coating conditions. Contact angle measurements and surface energy calculations as well as infrared and X-ray photoelectron spectroscopy are used to evaluate polymer chemical modifications. Morphological changes are studied through scanning electron and atomic force microscopy. Results show the ability of plasma treatment to create active oxydised functional groups on the polypropylene surface. These groups lead to a proper wetting of the polymer by the silane. Shear strength of single-lap bonding of polypropylene with a polyurethane adhesive suffers a significant improvement when the silane coating is applied on previously plasma activated samples. It has been also demonstrated that the silane curing conditions play a decisive role on the adhesion response. Finally, the stability of the silane solution is tested up to 30 days, yielding diminished but still acceptable adhesion strength values.

  12. Modification of polycarbonate and polypropylene surfaces by argon ion cluster beams.

    Czech Academy of Sciences Publication Activity Database

    Biederman, H.; Slavinská, D.; Boldyreva, H.; Lehmberg, H.; Takaoka, G.; Matsuo, J.; Kinpara, H.; Zemek, Josef

    2001-01-01

    Ro?. 19, ?. 6 (2001), s. 2050-2056. ISSN 0734-2101 R&D Projects: GA MŠk ME 177 Institutional research plan: CEZ:AV0Z1010914; CEZ:MSM113200002 Keywords : polycarbonate * polypropylene * surfometer * atomic force microscop * X-ray photoelectron spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.448, year: 2001

  13. Evaluation of the mechanical and thermal properties of coffee tree wood flour - polypropylene composites

    Science.gov (United States)

    Columbian coffee trees are subject to frequent replacement plantings due to disease and local climate changes which makes them an ideal source of wood fibers for wood plastic composites (WPC). Composites of polypropylene (PP) consisting of 25% and 40% by weight of coffee wood flour (CF) and 0% or 5%...

  14. Origin of toughness in polypropylene: the effect of molecular mobility in the amorphous phase.

    Czech Academy of Sciences Publication Activity Database

    Policianová, Olivia; Urbanová, Martina; Hodan, Ji?í; Kotek, Ji?í; Brus, Ji?í

    International Society of Magnetic Resonance , 2015. P 74. [Alpine Conference on Solid-State NMR /9./. 13.09.2015-17.09.2015, Chamonix Mont-Blanc] R&D Projects: GA ?R(CZ) GA13-29009S Institutional support: RVO:61389013 Keywords : ssNMR * isotactic polypropylene * toughness Subject RIV: JI - Composite Materials

  15. Polypropylene /Aspen/ liquid polybutadienes composites: maximization of impact strength, tensile and modulus by statistical experimental design.

    Czech Academy of Sciences Publication Activity Database

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

    2005-01-01

    Ro?. 99, - (2005), s. 10-11. ISSN 0009-2770. [International Conference on Polymeric Materials in Automotive , Slovak Rubber Conference /17./. 10.5.2005-12.5.2005, Bratislava] Institutional research plan: CEZ:AV0Z40500505 Keywords : polypropylene * Aspen-PP composite Subject RIV: CD - Macromolecular Chemistry

  16. Structure evolution of .alpha.- and .beta.-polypropylenes upon UV irradiation: A multiscale comparison.

    Czech Academy of Sciences Publication Activity Database

    Obadal, M.; ?ermák, R.; Raab, Miroslav; Verney, V.; Commereuc, S.; Fraisse, F.

    2005-01-01

    Ro?. 88, ?. 3 (2005), s. 532-539. ISSN 0141-3910 R&D Projects: GA ?R(CZ) GA106/02/1249 Keywords : .beta.-polypropylene * photo-oxidation * structure evolution Subject RIV: JJ - Other Materials Impact factor: 1.749, year: 2005

  17. Repair of a deep digital tendon deficit in a horse using a polypropylene implant.

    OpenAIRE

    Crawford, W H; Ingle, J E

    1997-01-01

    A yearling horse was treated for a chronic wound with a 4 cm deficit in the deep digital tendon. The gap in the tendon was bridged with paired polypropylene braided implants designed for use as a ligament augmentation device. Uncomplicated healing and return to function occurred.

  18. Development of bio/blood compatible polypropylene through low pressure nitrogen plasma surface modification

    International Nuclear Information System (INIS)

    Surface modification of polypropylene by nitrogen containing plasma was performed in this work in order to improve the wettability which resulted in enhanced biocompatibility and blood compatibility. Various nitrogen containing functional groups as well as oxygen containing functional groups were found to be incorporated to the polymer surface during plasma treatment and post plasma reaction respectively. Wettability of the polymers was evaluated by static contact angle measurement to show the improvement in hydrophilicity of plasma treated polypropylene. Cross linking and surface modification were reported to be dominating in the case of nitrogen plasma treatment compared to degradation. The effect of various process variables namely power, pressure, flow rate and treatment time on surface energy and weight loss was studied at various levels according to the central composite design of response surface methodology (RSM). Except pressure the other variables resulted in increased weight loss due to etching whereas with increasing pressure weight loss was found to increase and then decrease. The effect of process variables on surface morphology of polymers was evaluated by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Well spread fibroblast cells on nitrogen plasma treated polypropylene due to the presence of CO, NH2+ and NH+ was observed. Reduced platelet adhesion and increased partial thromboplastin time evidenced the increased blood compatibility. - Highlights: ? Improved biocompatibility and blood compatibility of polypropylene. ? Nitrogen plasma surface modification. ? Maintaining a balance between polar group incorporation and weight loss due to etching. ? Optimization of process conditions by response surface methodology.

  19. Non-linear tensile creep of polypropylene: time-strain superposition and creep prediction.

    Czech Academy of Sciences Publication Activity Database

    Kola?ík, Jan; Pegoretti, A.

    2006-01-01

    Ro?. 47, ?. 1 (2006), s. 346-356. ISSN 0032-3861 R&D Projects: GA ?R GA106/04/1051 Institutional research plan: CEZ:AV0Z40500505 Keywords : polypropylene * tensile creep * free volume Subject RIV: JI - Composite Materials Impact factor: 2.773, year: 2006

  20. Morphological factor in the melting point depression of polypropylene by alkanes.

    Czech Academy of Sciences Publication Activity Database

    Šimek, L.; Dostál, J.; Bohdanecký, Miloslav

    2001-01-01

    Ro?. 42, ?. 21 (2001), s. 8897-8900. ISSN 0032-3861 R&D Projects: GA AV ?R KSK4050111 Institutional research plan: CEZ:AV0Z4050913 Keywords : isotactic polypropylene * n-alkanes * melting point depression Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.681, year: 2001

  1. Crystallization and melting behavior of nanoclay-containing polypropylene/poly(trimethylene terephthalate) blends

    OpenAIRE

    Jafari, S. H.; A. Kalati-vahid; H. A. Khonakdar; A. Asadinezhad; U. Wagenknecht; Jehnichen, D

    2012-01-01

    This contribution concerns preparation and characterization of polypropylene (PP)/poly(trimethylene terephthalate) (PTT) melt-mixed blends in the presence of organically-modified montmorillonite nanoclays and functional compatibilizers. Immiscibility and nanocomposite formation were confirmed via transmission electron microscopy. An intercalated structure was observed by wide angle X-ray diffraction technique. Crystallization, and melting characteristics were studied by differential scanning ...

  2. Radiation compatibilization of polyamide-6/polypropylene blends, enhanced by the presence of compatibilizing agent

    International Nuclear Information System (INIS)

    Radiation compatibilization of polyamide-6 (PA6)/polypropylene (PP) blends was obtained by pre-irradiation of PP by gamma or electron beam irradiation, and enhanced in blends with PP-g-MA (maleic anhydride). Thermal behavior and morphological development were determined by DSC, X-ray and SEM. Compatibilization was confirmed by xylene extraction and Molau test

  3. Spinning, drawing and physical properties of polypropylene nanocomposite fibers with fumed nanosilica.

    Czech Academy of Sciences Publication Activity Database

    Dabrowska, I.; Fambri, L.; Pegoretti, A.; Šlouf, Miroslav; Vacková, Ta?ana; Kolarik, J.

    2015-01-01

    Ro?. 9, ?. 3 (2015), s. 277-290. ISSN 1788-618X R&D Projects: GA ?R(CZ) GA14-17921S Institutional support: RVO:61389013 Keywords : polypropylene * fibers * nanocomposites Subject RIV: JI - Composite Materials Impact factor: 2.761, year: 2014

  4. The stopping power and energy straggling of heavy ions in silicon nitride and polypropylene.

    Czech Academy of Sciences Publication Activity Database

    Mikšová, Romana; Hnatowicz, Vladimír; Macková, Anna; Malinský, Petr; Slepi?ka, P.

    2015-01-01

    Ro?. 354, JUL (2015), s. 205-209. ISSN 0168-583X R&D Projects: GA ?R(CZ) GBP108/12/G108; GA MŠk LM2011019 Institutional support: RVO:61389005 Keywords : stopping power * heavy ions * polypropylene * silicon nitride Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.124, year: 2014

  5. Polypropylene-clay nanocomposites: Effect of chlorosulfonated coupling agent on clay delamination.

    Czech Academy of Sciences Publication Activity Database

    Kotek, Ji?í; Kelnar, Ivan; Studenovský, Martin; Baldrian, Josef

    San Francisco : Delta Kunststoffe Company, 2004, s. 1-10. [Conference on Nanocomposites. San Francisco (US), 01.09.2004-03.09.2004] R&D Projects: GA AV ?R IBS4050351 Institutional research plan: CEZ:AV0Z4050913 Keywords : polypropylene * nanocomposites * melt-compounding Subject RIV: CD - Macromolecular Chemistry

  6. Characterization of calcium carbonate obtained from oyster and mussel shells and incorporation in polypropylene

    Scientific Electronic Library Online (English)

    Michele Regina Rosa, Hamester; Palova Santos, Balzer; Daniela, Becker.

    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 polypropy [...] lene 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.

  7. Description and optimizing of polypropylene blends flow behavior for foaming processes.

    Czech Academy of Sciences Publication Activity Database

    Piyamanocha, P.; Sedlá?ek, T.; Filip, Petr; Sáha, P.

    Banff : Polymer Processing Society, 2010, Article no. R02-225. ISBN N. [Annual Meeting of Polymer Processing Society /26./. Banff (CA), 04.07.2010-08.07.2010] Grant ostatní: GA MPO(CZ) 2A-1TP1/126 Institutional research plan: CEZ:AV0Z20600510 Keywords : polypropylene blend * shear behaviour * elongational behaviour Subject RIV: BK - Fluid Dynamics

  8. On explicit modeling of polypropylene fiber effects on hydro-thermal behavior of heated concrete

    Directory of Open Access Journals (Sweden)

    Tran V.H.

    2013-09-01

    Full Text Available This work focuses on the evaluation of the probability of percolation of polypropylene fibers (PPF in creating a permeable network within heated concreted due to temperature induced degradation of fibers. Therefore, the intrinsic permeability supply of heated concrete containing PPF is accordingly estimated by a homogenization technique applied to the 3D heterogeneous microstructure.

  9. Structure of injection-molded beta-polypropylene and research perspectives of its degradability.

    Czech Academy of Sciences Publication Activity Database

    Obadal, M.; ?ermák, R.; Raab, Miroslav; Verney, V.; Commereuc, S.; Fraisse, F.

    ClermontFerrand : Groupe Francais d études et d applications des Polymeres, 2003, s. 3-4. [Cycle de vie des polymeres.. Clermont-Ferrand (FR), 25.11.2003-27.11.2003] R&D Projects: GA ?R GA106/02/1249 Institutional research plan: CEZ:AV0Z4050913 Keywords : polypropylene * structure * degradation Subject RIV: JJ - Other Materials

  10. Air-Coupled Piezoelectric Transducers with Active Polypropylene Foam Matching Layers

    OpenAIRE

    Tomás E. Gómez Alvarez-Arenas

    2013-01-01

    This work presents the design, construction and characterization of air-coupled piezoelectric transducers using 1–3 connectivity piezocomposite disks with a stack of matching layers being the outer one an active quarter wavelength layer made of polypropylene foam ferroelectret film. This kind of material has shown a stable piezoelectric response together with a very low acoustic impedance (

  11. SYNTHESIS AND CHARACTERIZATION OF POLYPROPYLENE-SILICA, ALUMINA AND TITANIA NANOPARTICLES, PREPARED BY MELTING

    Scientific Electronic Library Online (English)

    F, ORELLANA; J, LISPERGUER; C, NUÑEZ.

    2014-03-01

    Full Text Available Polypropylene composites with 5 to 10% of SiO2, Al2O3 y TiO2 nanoparticles were synthesized. The oxides were obtained using the sol-gel technique and were added to the molten polypropylene. The morphology of nanoparticles was observed by scanning electron microscopy and showed that the incorporation [...] of TiO2 and SiO2 gels produces high dispersion of the filler, while the use of Al2O3 results in aggregates of these nanoparticles in the polymer matrix. The X-ray diffractogram of the composites revealed a displacement of characteristics lines of polypropylene and an increment of the interplanar spaces, indicating some interaction between the components and the predominance intercalation of oxides. Through FT-IR it was noticed the presence of functional groups attributable to the filler nanoparticles. The crystallization, the fusion behaviour and the thermal stability of the composites was studied using differential scanning calorimetry and thermogravimetric analysis it was found a reduction in the crystallization temperature and increment in the thermal stability of the polypropylene matrix due to the action of the silica, alumina an titania nanoparticles.

  12. Origin of toughness in .beta.-polypropylene: the effect of molecular mobility in the amorphous phase.

    Czech Academy of Sciences Publication Activity Database

    Policianová, Olivia; Hodan, Ji?í; Brus, Ji?í; Kotek, Ji?í

    2015-01-01

    Ro?. 60, 9 March (2015), s. 107-114. ISSN 0032-3861 R&D Projects: GA ?R(CZ) GA13-29009S Institutional support: RVO:61389013 Keywords : isotactic polypropylene * ?-modification * toughness Subject RIV: JI - Composite Materials Impact factor: 3.562, year: 2014

  13. Nanocomposites of polypropylene/titanate nanotubes: morphology, nucleation effects of nanoparticles and properties.

    Czech Academy of Sciences Publication Activity Database

    Mikešová, Jana; Šlouf, Miroslav; Gohs, U.; Popelková, Daniela; Vacková, Ta?ana; Vu, Ngoc Húng; Kratochvíl, Jaroslav; Zhigunov, Alexander

    2014-01-01

    Ro?. 71, ?. 4 (2014), s. 795-818. ISSN 0170-0839 R&D Projects: GA ?R GAP205/10/0348 Institutional support: RVO:61389013 Keywords : titanate nanotubes * polypropylene nanocomposites * nucleation effect Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.438, year: 2014

  14. The effects of gamma irradiation on the physical properties of polypropylene and polyethylene films

    International Nuclear Information System (INIS)

    Investigations on the physical properties of several packaging films i.e. polypropylene, low density polyethylene (LDPE) and high density polyethylene (HDPE) as affected by radiation at doses of 10 kGy up to 50 kGy have been carried out. The parameter used were: tensile strength, elongation at break, tear strength, Haze test, leakage of envelope, detection of pinholing and drop-test. The effects of 6 months storage on irradiated and unirradiated polypropylene films were also investigated. The results showed that radiation up to 50 kGy did not give any measurable changes on polyethylene films where as polypropylene films gave some measurable changes at a radiation dose of 30 kGy. The changes depended on the thickness and the raw materials of the plastic films. Storage for 6 months gave some measurable changes on all of the parameters examined. The positive results of the leakage test of envelopes, detection of pinholing and drop-test were observed on HDPE, LDPE and polypropylene films with thickness of less than 0.04 mm, 0.08 mm and 0.03 mm respectively. (author)

  15. Estudo comparativo entre as técnicas de sutura total e serosubmucosa em anastomoses colônicas na presença de um protetor intraluminar em cães Comparative study of all-layers suture and extramucosal single layer suture with an intraluminal protector in dogs

    Directory of Open Access Journals (Sweden)

    Cíntia Lourenço Santos

    2007-08-01

    Full Text Available OBJETIVO: Avaliar a cicatrização comparando as técnicas de sutura total e parcial em anastomoses colônicas término-terminais na presença de um protetor intraluminar confeccionado a partir de um dreno de Penrose. MÉTODOS: Foram realizadas anastomoses colônicas em 10 cães nos quais foi suturado a mucosa / submucosa um protetor intraluminar por meio da eversão do segmento intestinal proximal em 10 cm. Os animais foram distribuidos em dois grupos experimentais: Grupo 1 - sutura total e Grupo 2 - sutura serosubmucosa. Os animais foram reoperados com sete dias de pós-operatório para coleta de material e subseqüente análise histopatológica. RESULTADOS: Observamos no exame histopatológico das anastomoses realizadas com sutura serosubmucosa (Grupo 2 uma melhor cicatrização caracterizada por um menor infiltrado inflamatório e por uma maior integridade das camadas intestinais quando comparadas com o Grupo 1. CONCLUSÃO: O uso da técnica de sutura parcial mostrou-se superior a de sutura total nas anastomoses colônicas na presença de protetor intraluminar.BACKGROUND: This study aims to evaluate the colonic anastomotic healing testing of all layers suture and single layer suture using an intraluminal protector. The intraluminal protector was shaped from a Penrose drain and then fixed 10 cm from the superior end of the anastomotic site. METHODS: Colonic anastomoses were done in 10 dogs, which were sutured, in the proximal segment with an intraluminal protector made of Penrose n.3 drain, using interrupted mucosal / submucosal suture. In the subsequent anastomoses, the animals were subdivided in two experimental groups: 1 - in all layers and 2 - extramucosal. In the seventh postoperative day, a tissue fragment was collected for histopathological analysis. RESULTS: Group 2 histopathological examinations had a better scar (extramucosal suture, characterized by a lesser inflammatory process than in animals in which all layers suture was used (group 1. CONCLUSION: The use of extramucosal suture was better than total suture in colonic anastomoses with the presence of an intraluminal protector.

  16. Estudo comparativo entre as técnicas de sutura total e serosubmucosa em anastomoses colônicas na presença de um protetor intraluminar em cães / Comparative study of all-layers suture and extramucosal single layer suture with an intraluminal protector in dogs

    Scientific Electronic Library Online (English)

    Cíntia Lourenço, Santos; Edmundo Jorge, Abílio; André Lacerda de Abreu, Oliveira; Carlos Magno Anselmo, Mariano; Anderson Teixeira, Nunes; Eulógio Carlos Queiroz de, Cravalho.

    2007-08-01

    Full Text Available OBJETIVO: Avaliar a cicatrização comparando as técnicas de sutura total e parcial em anastomoses colônicas término-terminais na presença de um protetor intraluminar confeccionado a partir de um dreno de Penrose. MÉTODOS: Foram realizadas anastomoses colônicas em 10 cães nos quais foi suturado a muco [...] sa / submucosa um protetor intraluminar por meio da eversão do segmento intestinal proximal em 10 cm. Os animais foram distribuidos em dois grupos experimentais: Grupo 1 - sutura total e Grupo 2 - sutura serosubmucosa. Os animais foram reoperados com sete dias de pós-operatório para coleta de material e subseqüente análise histopatológica. RESULTADOS: Observamos no exame histopatológico das anastomoses realizadas com sutura serosubmucosa (Grupo 2) uma melhor cicatrização caracterizada por um menor infiltrado inflamatório e por uma maior integridade das camadas intestinais quando comparadas com o Grupo 1. CONCLUSÃO: O uso da técnica de sutura parcial mostrou-se superior a de sutura total nas anastomoses colônicas na presença de protetor intraluminar. Abstract in english BACKGROUND: This study aims to evaluate the colonic anastomotic healing testing of all layers suture and single layer suture using an intraluminal protector. The intraluminal protector was shaped from a Penrose drain and then fixed 10 cm from the superior end of the anastomotic site. METHODS: Coloni [...] c anastomoses were done in 10 dogs, which were sutured, in the proximal segment with an intraluminal protector made of Penrose n.3 drain, using interrupted mucosal / submucosal suture. In the subsequent anastomoses, the animals were subdivided in two experimental groups: 1 - in all layers and 2 - extramucosal. In the seventh postoperative day, a tissue fragment was collected for histopathological analysis. RESULTS: Group 2 histopathological examinations had a better scar (extramucosal suture), characterized by a lesser inflammatory process than in animals in which all layers suture was used (group 1). CONCLUSION: The use of extramucosal suture was better than total suture in colonic anastomoses with the presence of an intraluminal protector.

  17. Improvement of adhesion properties of polypropylene substrates by methyl methacrylate UV photografting surface treatment

    International Nuclear Information System (INIS)

    Highlights: ? Useful at industrial level as a pre-treatment stage with relatively low cost. ? In depth characterization of surface changes in a qualitative and quantitative way. ? Remarkable increase in adhesion (shear and T-peel) properties of PP substrates. ? Remarkable increase in wetting properties of PP for enhanced surface activity. -- Abstract: Polypropylene is a widely used commodity plastic from an industrial point of view. Typical applications include both low and high technological content, as it has a good balance between overall properties, processability and cost. However, it is important to remark its intrinsic low surface energy which leads to high chemical inertness. This has an important restriction on some technical applications that require joining and/or finishing processes such as painting. Therefore, the use of polypropylene in these applications requires previous surface modification in order to increase surface activity. Surface modification can be carried out by physical processes such as plasmas or by chemical ways. Surface chemical modification is characterized by relatively low cost and easy implementation at industrial scale. In this work, we have used a chemical process to improve adhesion properties on polypropylene substrates. The selected method has been ultraviolet photografting of methyl methacrylate (MMA) monomer. This process allows increasing surface activity and this has a positive effect on polypropylene-polypropylene adhesion joints. Surface changes have been followed by contact angle measurements and subsequent surface free energy calculation. The evolution of mechanical properties of adhesion joints (T-peel and shear conditions) in terms of the previous exposure time to UV radiation has been evaluated. Optical microscopy (OM) and scanning electron microscopy (SEM) have been used to characterize adhesion fracture type.

  18. Effect of nanoclay content and compatibilizer on viscoelastic properties of montmorillonite/polypropylene nanocomposites

    International Nuclear Information System (INIS)

    Highlights: ? Synthesis of nanocomposites were carried out using master batch route. ? Properties of nanocomposites were obtained with and without compatabilizers. ? Better viscoelastic properties resulted with nanoclay addition. ? Use of compatibilizer resulted in degradation of properties of nanocomposites. ? AFM confirmed the experimental results. -- Abstract: This paper deals with preparation of nanocomposites using modified nanoclay (organoclay) and polypropylene (PP), with, and without compatibilizer (m-TMI-g-PP) to study the effects of modified nanoclay and compatibilizer on viscoelastic properties. Nanocomposites were prepared in two steps; compounding of master batch of nanoclay, polypropylene and m-TMI-g-PP in a torque rheometer and blending of this master-batch with polypropylene in a twin-screw extruder in the specific proportions to yield 3–9% nanoclay by weight in the composite. Dynamic Mechanical Analysis (DMA) tests were carried out to investigate the viscoelastic behavior of virgin polypropylene and nanocomposites. The dynamic mechanical properties such as storage modulus (E?), loss modulus (E?) and damping coefficient (tan ?) of PP and nano-composites were investigated with and without compatibilizer in the temperature range of ?40 °C to 140 °C at a step of 5 °C and frequency range of 5 Hz to 100 Hz at a step of 10 Hz. Storage modulus and loss modulus of the nano-composites was significantly higher than virgin polypropylene throughout the temperature range. Storage modulus of the composites increased continuously with increasing nano-content from 3% to 9%. Composites prepared with compatibilizer exhibited inferior storage modulus than the composites without compatibilizer. Surface morphology such as dispersion of nanoclay in the composites with and without compatibilizer was analyzed through Atomic Force Microscope (AFM) that explained the differences in viscoelastic behavior of composites.

  19. Role of suture diameter and vessel insertion position in the establishment of the middle cerebral artery occlusion rat model

    OpenAIRE

    TANG, QIQIANG; HAN, RUODONG; XIAO, HAN; SHI, LILI; Shen, Jilong; LUN, QINGLI; Li, Jun

    2013-01-01

    The aim of the present study was to explore the role of suture diameter and vessel insertion position in the preparation of the middle cerebral artery occlusion (MCAO) rat model. A total of 84 Sprague-Dawley rats (weighing 250–300 g) were randomly divided to three groups: group A (type 1.0, suture diameter 0.16–0.17 mm and tip 0.21–0.22 mm); group B (type 2.0; suture diameter, 0.22–0.23 mm; tip, 0.27–0.28 mm); and group C (type 3.0; suture diameter, 0.28–0.29 mm; and tip, 0.33–0.34 mm). The a...

  20. Traction endurance biomechanical study of metallic suture anchors at different insertion angles

    Directory of Open Access Journals (Sweden)

    Azato Flávia Namie

    2003-01-01

    Full Text Available The suture anchors' insertion angle and its traction resistance are the main subjects of this study. Twenty trials were realized using threaded suture anchors in four diferents angulations (30º /45º /60º /90º in human bone (distal femur and another twenty trials in artificial bone (SawboneTM. The anchors were pulled out being tractioned uprightly from its bone surface by a Kratos Universal test machine. The human bone results found no relation between the main subjects of this study, so whithout statistical value. On the other hand at the artificial bone the insertion angle of 90º beared more traction, being statistically significant compared to the other angles.