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Sample records for 10-0 polypropylene suture

  1. Polypropylene suture--is it safe?

    Science.gov (United States)

    Calhoun, T R; Kitten, C M

    1986-07-01

    Polypropylene suture has steadily gained popularity for use in vascular and cardiac surgical procedures because of its long-term tensile strength and minimal tissue trauma. However, recently some questions have arisen concerning its safety. We recently had two cases of polypropylene fracture, one occurring early and the other late after operation. Comparison and collation of these two cases with other reports leads to the conclusion that polypropylene suture is safe in most situations, but care must be taken to avoid instrumentation trauma and kinking stresses at knots, which probably explain most of the reported cases of polypropylene failure. In addition, polypropylene probably should not be used in graft-to-graft anastomoses in which the continual sawing stresses of two rigid structures appears to lead to an excessive incidence of late suture fracture with resultant false aneurysm formation.

  2. A comparative study of outcome of the absorbable suture polydioxanone and nonabsorbable suture polypropylene in laparotomy wound closure

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    Kiran Shankar H.

    2016-06-01

    Full Text Available Background: Abdominal wound closure is one of the common operations for a general surgeon. Prevention of complications is important to reduce post-operative morbidity and mortality. Post-operative wound pain, wound infection, wound dehiscence, suture sinus formation; palpable knots and incisional hernia are the parameters are to be studied. Therefore, the present study was undertaken to compare polydioxanone and polypropylene suture material for abdominal fascial closure regarding morbidity in terms of post-operative wound complications. Methods: Patients admitted in the department of surgery, who undergo laparotomy operations, with midline abdominal incisions were included in the study. The recruited subjects were divided into Group-A, whom abdominal incisions are closed with non-absorbable suture material polypropylene and Group-B whom abdominal incisions are closed with absorbable suture material polydioxanone. Data was expressed as percentages. Results: The incidence of wound pain was observed in all the patients in both immediate and delayed post-operative period in the polypropylene suture material compared to polydioxanone. The incidence of wound infection was higher in polypropylene (24% compared to PDS (2%. There were 4% cases of wound dehiscence in the present study. The incidence of suture sinus formation was higher in the polypropylene suture material (9% compared to the polydioxanone suture material (2% in the delayed postoperative period. The incidence of palpable knots was higher in the polypropylene suture material (23% compared to the polydioxanone suture material. No cases of incisional hernia were reported with polydioxanone suture material. Conclusions: The overall morbidity from abdominal closure was considerably reduced in the Polydioxanone group. We encountered reduction in wound complications like burst abdomen, wound infection, wound pain, suture sinus formation, palpable knots and incisional hernia. Therefore

  3. 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.

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

    Science.gov (United States)

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

    2014-04-01

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

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

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    Pankaj Shivhare

    2014-06-01

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

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

    OpenAIRE

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

    2016-01-01

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

  7. Tram-Track Suture Technique for Pupillary Capture of a Scleral Fixated Intraocular Lens

    Science.gov (United States)

    Kim, Sung In; Kim, Kiseok

    2016-01-01

    Purpose To report a new technique using tram-track suture for pupillary capture of a scleral fixated posterior chamber intraocular lens (PC-IOL) to reposition the tilted IOL. Methods In this prospective interventional case series, we describe a tram-track suture for pupillary capture of a scleral fixated PC-IOL. A long straight needle with double-armed 10-0 polypropylene is passed behind the iris and just above the optic portion (tilted forward) of the IOL. The other straight needle with double-armed 10-0 polypropylene is passed just below the optic portion (tilted backward) of the IOL. After the IOL is repositioned properly, the polypropylene sutures are gently pulled and tied. Results Four eyes of 4 patients underwent tram-track suture for pupillary capture of a scleral fixated PC-IOL. No intra- or postoperative complications were noted, and no pupillary captures were detected during the follow-up period. Conclusions The tram-track suture technique provides good centration and stability of a PC-IOL. This technique is an easy and effective way to reposition pupillary capture of an IOL. Further, it is also minimally invasive as it maintains a closed system. PMID:27462257

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

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    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

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

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    Álvaro Gianlupi

    2004-04-01

    Full Text Available OBJETIVO: Comparar a fixação da tela de prolipropileno na correção de defeitos músculo-aponeuróticos da parede abdominal com fio absorvível (poliglactina 910 e fio inabsorvível (polipropileno. MÉTODOS: Oitenta e um ratos machos da linhagem Wistar foram submetidos a ressecção longitudinal de um segmento músculo-aponeurótico e peritoneal (3x2 cm da parede abdominal, seguida por reforço com tela de polipropileno, em forma de ponte sobre a aponeurose. Foram distribuídos em dois grupos de acordo com o fio usado para fixação da tela: grupo poliglactina 910 - fixada com 8 pontos separados e eqüidistantes em forma de "U" com fio 4-0; e grupo polipropileno - fixada com fio 4-0. A pele foi suturada com fio de nylon 4-0. Após 90 dias, os animais foram submetidos à eutanásia e avaliados macroscopicamente, quanto à presença de hérnia e avaliação histológica da reação inflamatória crônica, absorção do fio e percentagem de fibrose pela técnica vídeo-morfométrica assistida por computador. Utilizaram-se as técnicas de coloração de hematoxilina-eosina e picrossírius. RESULTADOS: Não houve diferença estatisticamente significante entre os grupos, quanto à presença de hérnia incisional (p=0,194. Houve maior fibrose no grupo polipropileno pela avaliação histológica de reação inflamatória crônica, o que não foi verificado quando avaliado pela técnica vídeo-morfométrica (p=0,0005. Não houve diferença entre os grupos quando avaliados os gigantócitos, linfócitos e neutrófilos. Houve maior número de macrófagos no grupo polipropileno (p=0,02. Não houve absorção do fio poliglactina 910 após 90 dias. CONCLUSÃO: A fixação de tela de polipropileno pode ser feita com êxito com fios absorvíveis como a poliglactina 910.PURPOSE: The aim of this study is to assess fixation of a polypropylene mesh in the repair of incisional hernias comparing an absorbable (polyglactin 910 suture and an inabsorbable

  10. Half-bow sliding knot: modified suture technique for scleral fixation using the corneoscleral pocket.

    Science.gov (United States)

    Chee, Soon-Phaik

    2011-09-01

    A modified suture technique for precise knot placement in the Hoffman corneoscleral pocket technique of scleral fixation is described. Both loops of the polypropylene suture passing from the intraocular device through the sclera and conjunctiva are retrieved from the pocket. A loop of suture is pulled through 3 suture throws made using the second suture loop, forming a half bow. Centration of the intraocular lens (IOL)-capsular bag is checked. If the suture tension is too tight, the surgeon can easily undo the knot of the half-bow knot by pulling it free and can then retie the sliding knot. When the IOL-capsular bag is centered, the suture loop is cut and the free end removed. The second suture end is retrieved from the pocket, and knot tying is completed without further adjustment to the tension. Posterior pressure on the intraocular device centers it and settles the knot within the sclera at the fixation point.

  11. 15 CFR 10.0 - General.

    Science.gov (United States)

    2010-01-01

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

  12. Biocompatibility and biomechanical analysis of elastic TPU threads as new suture material.

    Science.gov (United States)

    Vogels, Ruben R M; Lambertz, Andreas; Schuster, Philipp; Jockenhoevel, Stefan; Bouvy, Nicole D; Disselhorst-Klug, Catherine; Neumann, Ulf P; Klinge, Uwe; Klink, Christian D

    2017-01-01

    High suture tension is one of the causes for many wound-healing problems. Constriction of tissue within the suture loops of nonelastic sutures can lead to cutting of the suture through tissues and necrosis of the tissue within these loops. The use of elastic materials in new suture types could give the material the ability to adapt tension to the tissue requirements and subsequently lead to more vital tissue within its loops. We evaluated the foreign body host response, as indicator of biocompatibility, to a new thermoplastic poly(carbonate) urethane (TPU) synthetic suture material in a rat model compared with standard nonelastic polypropylene (PP) sutures. Tissue samples were collected at 7 and 21 days, and host response was evaluated. Subsequently, suture tension curves of the new elastic sutures for the first 30 min after knotting were recorded in a pig model. The new TPU sutures showed an improved foreign body response when compared with that of PP, with a reduction in the amount of macrophages surrounding the material. Tension experiments showed a superior tension curve for TPU sutures, with a major reduction in peak suture tension when compared with that of standard PP sutures, while still retaining adequate tension after 30 min. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 99-106, 2017.

  13. 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.

  14. GENIE Production Release 2.10.0

    Energy Technology Data Exchange (ETDEWEB)

    Alam, M. [Aligarh Muslim Univ., Aligarh (India). Dept. of Physics; Andreopoulos, C. [Univ. of Liverpool (United Kingdom). Dept. of Physics; Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL); Athar, M. [Aligarh Muslim Univ., Aligarh (India). Dept. of Physics; Bodek, A. [Univ. of Rochester, NY (United States). Dept. of Physics; Christy, E. [Hampton Univ., Hampton, VA (United States). Dept. of Physics; Coopersmith, B. [Univ. of Rochester, NY (United States). Dept. of Physics; Dennis, S. [Univ. of Warwick, Coventry (United Kingdom). Dept .of Physics; Dytman, S. [Univ. of Pittsburgh, PA (United States). Dept. of Physics and Astronomy; Gallagher, H. [Tufts Univ., Medford, MA (United States). Dept. of Physics and Astronomy; Geary, N. [Univ. of Pittsburgh, PA (United States). Dept. of Physics and Astronomy; Golan, T. [Univ. of Rochester, NY (United States). Dept. of Physics; Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Hatcher, R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Hoshina, K. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics. Wisconsin IceCube Particle Astrophysics Center; Liu, J. [College of William and Mary, Williamsburg, VA (United States). Dept. of Physics; Mahn, K. [Michigan State Univ., East Lansing, MI (United States). Dept. of Physics and Astronomy; Marshall, C. [Univ. of Rochester, NY (United States). Dept. of Physics; Morrison, J. [Michigan State Univ., East Lansing, MI (United States). Dept. of Physics and Astronomy; Nirkko, M. [Univ. of Bern (Switzerland). Albert Einstein Center for Fundamental Physics. Lab. for High Energy Physics (LHEP); Nowak, J. [Lancaster Univ. (United Kingdom). Dept. of Physics; Perdue, G. N. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Yarba, J. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-12-25

    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.

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

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    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

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

    Science.gov (United States)

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

    1996-01-01

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

  17. Hypersensitivity to Suture Anchors

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    Masafumi Goto

    2013-01-01

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

  18. EFFECTS OF DIFFERENT SUTURE MATERIALS ON TISSUE HEALING

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    Fırat SELVİ

    2016-01-01

    Full Text Available Purpose: The purpose of this study was to investigate the healing differences in between four different widely used suture materials in the oral surgery practice, including silk (Perma- Hand; Ethicon, INC., Somerville, NJ, USA, polypropylene (Prolene; Ethicon, INC., Somerville, NJ, USA, coated polyglactin 910 (Ethicon, INC., Somerville, NJ, USA. and polyglecaprone 25 (Ethicon, INC., Somerville, NJ, USA . Materials and Methods: 20 male rats were randomly allocated into two groups depending on their sacrification days (post-operative 1st and the 7th days. Four longitudinal incision wounds, each 1cm in size, were created on the dorsum of each animal which were then primarily closed with four different types of sutures. Results: The effects of these suture materials on soft tissue healing were compared histopathologically, by means of density of the cells, necrosis, fibrosis, foreign body reaction, the presence of cells of acute and chronic infection. No statistically significant difference was observed between the groups regarding the density of the cells, necrosis, fibrosis, foreign body reaction, and the presence of the cells of acute & chronic infections. Of note, propylene showed slightly less tissue reaction among the other materials. Conclusion: The results of our study showed that there is no only one ideal suture material for surgical practice. The factors related to the patient, the type of the surgery and the quality of the tissue are important to decide an appropriate suture material.

  19. Craniofacial clefting and sutural dystopia.

    Science.gov (United States)

    Moore, M H; Edwards, T J; David, D J

    1991-07-01

    Sutural anomalies in conjunction with craniofacial clefting are unusual. A case of median frontal clefting is presented in which there was an absence of a normal metopic suture and replacement by paramedian frontal sutures. The association of an underlying brain anomaly, with attendant surgical difficulties, is noted, as are the radiological techniques of preoperative diagnosis.

  20. Corneoscleral abscess resulting from a broken suture after cataract surgery.

    Science.gov (United States)

    Cameron, J A; Huaman, A

    1994-01-01

    An 82-year-old man had pain and decreased vision in his right eye 15 months after uncomplicated cataract surgery. Examination revealed a large corneoscleral abscess with a 2 mm x 1 mm area of fluorescein staining at the base of a broken protruding 10-0 nylon suture. Streptococcus pneumoniae was isolated from both the suture and base of the ulcer. Despite intensive topical, subconjunctival, and systemic antibiotics, a large corneal perforation developed, necessitating a 10 mm tectonic penetrating keratoplasty. Long-term follow-up of patients after cataract surgery is important and should include an inspection of the limbal wound and removal of loose or broken exposed sutures. Suture-related complications will be eliminated if clinical studies prove the safety and efficacy of sutureless cataract surgery.

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

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    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.

  2. 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

  3. Stress-Softening and Residual Strain Effects in Suture Materials

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    Alex Elías-Zúñiga

    2013-01-01

    Full Text Available This work focuses on the experimental characterization of suture material samples of MonoPlus, Monosyn, polyglycolic acid, polydioxanone 2–0, polydioxanone 4–0, poly(glycolide-co-epsilon-caprolactone, nylon, and polypropylene when subjected to cyclic loading and unloading conditions. It is found that all tested suture materials exhibit stress-softening and residual strain effects related to the microstructural material damage upon deformation from the natural, undistorted state of the virgin suture material. To predict experimental observations, a new constitutive material model that takes into account stress-softening and residual strain effects is developed. The basis of this model is the inclusion of a phenomenological nonmonotonous softening function that depends on the strain intensity between loading and unloading cycles. The theory is illustrated by modifying the non-Gaussian average-stretch, full-network model to capture stress-softening and residual strains by using pseudoelasticity concepts. It is shown that results obtained from theoretical simulations compare well with suture material experimental data.

  4. Comparison of Subcuticular Suture Materials in Cesarean Skin Closure

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    Pınar Solmaz Hasdemir

    2015-01-01

    Full Text Available 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.

  5. First investigation of spider silk as a braided microsurgical suture.

    Science.gov (United States)

    Kuhbier, Joern W; Reimers, Kerstin; Kasper, Cornelia; Allmeling, Christina; Hillmer, Anja; Menger, Björn; Vogt, Peter M; Radtke, Christine

    2011-05-01

    Inhibition of axonal outgrowth accompanied by neuroma formation appears in microsurgical nerve repair as reaction to common microsuture materials like silk, nylon, or polyglycolic acid. In contrast, recent findings revealed advantages of spider silk fibers in guiding Schwann cells in nerve regeneration. Here, we asked if we could braid microsutures from native spider silk fibers. Microsutures braided of native spider dragline silk were manufactured, containing either 2 × 15 or 3 × 10 single fibres strands. Morphologic appearance was studied and tensile strength and stress-strain ratio (SSR) were calculated. The constructed spider silk sutures showed a median thickness of 25 μm, matching the USP definition of 10-0. Maximum load and tensile strength for both spider silk microsutures were significantly more than 2-fold higher than for nylon suture; SSR was 1.5-fold higher. All values except elasticity were higher in 3 × 10 strand sutures compared to 2 × 15 strand sutures, but not significantly. In this pilot study, we demonstrate the successful manufacture of microsutures from spider silk. With regards to the mechanical properties, these sutures were superior to nylon sutures. As spider silk displays high biocompatibility in nerve regeneration, its usage in microsurgical nerve repair should be considered.

  6. Suture Materials in Ophthalmic Surgery

    OpenAIRE

    KÖHLE, Ülkü; Demir, Canser Yılmaz

    2003-01-01

    Suture materials is one of the basic subjects which every surgeon should know. The operation of suturing, sewing together two sides of a wound, is probably one of the oldest in the history of medicine. Its purpose is to aid healing as atraumatically as possible and it has mainly the mechanical effect of holding the wound edges together. Different suture materials have been manufactured. Each material is suited to different types of tissue, but all must posses certain character...

  7. Fiber reinforced polypropylene nanocomposites

    OpenAIRE

    2007-01-01

    The aim of this thesis is to assess the feasibility of integrating nanoparticles into glass fiber (GF) reinforced isotactic polypropylene (iPP) composites via existing thermoplastic processing routes, and to investigate whether this results in significant improvements in the mechanical properties of the final composites. A longer term aim will be to extend the approach to the preparation of hybrid composites with added non-structural functionality. However, the nanoparticles that have provide...

  8. Fiber reinforced polypropylene nanocomposites

    OpenAIRE

    2008-01-01

    The aim of this thesis is to assess the feasibility of integrating nanoparticles into glass fiber (GF) reinforced isotactic polypropylene (iPP) composites via existing thermoplastic processing routes, and to investigate whether this results in significant improvements in the mechanical properties of the final composites. A longer term aim will be to extend the approach to the preparation of hybrid composites with added non-structural functionality. However, the nanoparticles that have provide...

  9. Current applications of endoscopic suturing

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Endoscopic suturing had previously been consideredan experimental procedure only performed in afew centers and often by surgeons. Now, however,endoscopic suturing has evolved sufficiently to be easilyimplemented during procedures and is more commonlyused by gastroenterologists. We have employed theApollo OverStitch suturing device in a variety of waysincluding closure of perforations, closure of full thicknessdefects in the gastrointestinal wall created duringendoscopic full thickness resection, closure of mucosotomiesduring peroral endoscopic myotomy, stentfixation, fistula closure, post endoscopic submucosaldissection, endoscopic mucosal resection and NaturalOrifice Transluminal Endoscopic Surgery defect closures,post-bariatric surgery gastrojejunal anastomosis revisionand primary sleeve gastroplasty.

  10. 31 CFR 10.0 - Scope of part.

    Science.gov (United States)

    2010-07-01

    ... Money and Finance: Treasury Office of the Secretary of the Treasury PRACTICE BEFORE THE INTERNAL REVENUE SERVICE § 10.0 Scope of part. This part contains rules governing the recognition of attorneys, certified public accountants, enrolled agents, and other persons representing clients before the Internal...

  11. 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 1.0

  12. Clinical Outcome and Wound Healing following Carpal Tunnel Decompression: A Comparison of Two Common Suture Materials

    Directory of Open Access Journals (Sweden)

    Robert J. MacFarlane

    2014-01-01

    Full Text Available Introduction. Debate exists amongst surgeons regarding the ideal suture material for skin closure in carpal tunnel decompression (CTD. This study compares wound related complications, patient satisfaction, and functional outcome following open carpal tunnel decompression in patients undergoing wound closure with either of two common absorbable and nonabsorbable suture types. Materials and Methods. 53 patients underwent CTD with either 4/0 polypropylene (ProleneTM, n = 28 or 4/0 polyglactin (Vicryl RapideTM, n = 25 for skin closure. QuickDASH, VAS satisfaction scores, and Southampton wound scores were assessed preoperatively and at 2 and 6 weeks postoperatively. Results. At 6 weeks the mean QuickDASH scores postoperatively were 18.54 and 17.70 for absorbable and nonabsorbable sutures, respectively, (P = 0.86. The mean VAS scores were 0.61 and 0.42 (P = 0.91, respectively. All patients achieved a Southampton wound score of 0 by 6 weeks except one, who achieved 1C in the nonabsorbable group, equivalent to mild erythema. There were no complications in either group. Conclusion. Both suture types are safe and effective materials for CTD, and we recommend surgeons to choose according to personal preference, handling properties, and resources available for suture removal.

  13. Sutured Floer homology and hypergraphs

    CERN Document Server

    Juhász, András; Rasmussen, Jacob

    2011-01-01

    By applying Seifert's algorithm to a special alternating diagram of a link L, one obtains a Seifert surface F of L. We show that the support of the sutured Floer homology of the sutured manifold complementary to F is affine isomorphic to the set of lattice points given as hypertrees in a certain hypergraph that is naturally associated to the diagram. This implies that the Floer groups in question are supported in a set of Spin^c structures that are the integer lattice points of a convex polytope. This property has an immediate extension to Seifert surfaces arising from homogeneous link diagrams (including all alternating and positive diagrams). In another direction, together with work in progress of the second author and others, our correspondence suggests a method for computing the "top" coefficients of the HOMFLY polynomial of a special alternating link from the sutured Floer homology of a Seifert surface complement for a certain dual link.

  14. 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.

  15. Tension of knotted surgical sutures shows tissue specific rapid loss in a rodent model

    Directory of Open Access Journals (Sweden)

    Klink Christian D

    2011-12-01

    Full Text Available Abstract Background Every surgical suture compresses the enclosed tissue with a tension that depends from the knotting force and the resistance of the tissue. The aim of this study was to identify the dynamic change of applied suture tension with regard to the tissue specific cutting reaction. Methods In rabbits we placed single polypropylene sutures (3/0 in skin, muscle, liver, stomach and small intestine. Six measurements for each single organ were determined by tension sensors for 60 minutes. We collected tissue specimens to analyse the connective tissue stability by measuring the collagen/protein content. Results We identified three phases in the process of suture loosening. The initial rapid loss of the first phase lasts only one minute. It can be regarded as cutting through damage of the tissue. The percentage of lost tension is closely related to the collagen content of the tissue (r = -0.424; p = 0.016. The second phase is characterized by a slower decrease of suture tension, reflecting a tissue specific plastic deformation. Phase 3 is characterized by a plateau representing the remaining structural stability of the tissue. The ratio of remaining tension to initial tension of phase 1 is closely related to the collagen content of the tissue (r = 0.392; p = 0.026. Conclusions Knotted non-elastic monofilament sutures rapidly loose tension. The initial phase of high tension may be narrowed by reduction of the surgeons' initial force of the sutures' elasticity to those of the tissue. Further studies have to confirm, whether reduced tissue compression and less local damage permits improved wound healing.

  16. 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.

  17. Braiding Parameters of Medical Silk Braided Suture

    Institute of Scientific and Technical Information of China (English)

    张佩华; 吴建华

    2001-01-01

    The relationships between braiding parameters and properties of medical silk braided suture are investigated. Experimental results indicate that the main factors affecting the suture properties include the proportion of core silk and shell silk, braiding density and braiding tension. The results show that the braiding technology significantly influences the suture properties and the optimal braiding parameters were obtained by using the regression method.

  18. Graft Suturing for Lenticule Dislocation after Descemet Stripping Automated Endothelial Keratoplasty

    Directory of Open Access Journals (Sweden)

    Wai-Kwan Wu

    2011-01-01

    Full Text Available Purpose: To report the mid-term outcomes of graft suturing in a patient with lenticule dislocation after Descemet stripping automated endothelial keratoplasty (DSAEK. Case Report: A 78-year old woman was found to have graft dislocation involving the nasal half of the cornea after uneventful DSAEK. Graft repositioning, refilling the anterior chamber with air, and placement of four full-thickness 10/0 nylon sutures over the detached area were performed two weeks after the initial surgery. The sutures were removed 6 weeks later. Serial specular microscopy and anterior segment optical coherence tomography were performed. At 18 months, there was good lenticule apposition and a clear graft. Conclusion: Anchoring sutures seem to be effective for management of graft detachment following DSAEK.

  19. Suture anchor versus suture through tunnel fixation for quadriceps tendon rupture: a biomechanical study.

    Science.gov (United States)

    Lighthart, William A; Cohen, David A; Levine, Richard G; Parks, Brent G; Boucher, Henry R

    2008-05-01

    This biomechanical study compared suture anchors versus transosseous sutures for repair of quadriceps tendon ruptures using a force of 150 N at a frequency of 0.5 Hz. No significant difference in displacement was found between the 2 techniques with initial loading or with load or no load after 1000 cycles. Displacement after 1000 cycles for suture anchors and bone tunnels was 4.65 and 4.50 mm, respectively. These findings suggest a possible role for suture anchors in repairing quadriceps tendon ruptures. Suture anchors are relatively expensive but require less dissection over the patella and do not involve suture placement about the patella tendon.

  20. Torrefied biomass-polypropylene composites

    Science.gov (United States)

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

  1. Is the pterygopalatomaxillary suture (sutura sphenomaxillaris) a growing suture in the fetus?

    Science.gov (United States)

    Vacher, C; Onolfo, J P; Barbet, J P

    2010-08-01

    The pterygopalatomaxillary suture is considered as having an important role in the posteroanterior growing of the maxilla. To determine whether this suture is a growing suture in the fetus, we performed a histological study of this suture in a fetus aged of 16 weeks of amenorrhea. Serial sections (5 microm) of the pterygopalatomaxillary suture area have been performed. Fibrous sutures are separating four pieces of ossification (maxilla, palatine bone, lateral and medial plates of the pterygoid process). A fibroblastic growing site has been observed on the dorsal aspect of the pterygopalatomaxillary suture, in contact to the anterior border of the lateral plate of the pterygoid process. The posteroanterior growing of maxilla is dependent on a growing suture located on the anterior border of the pterygoid process. The pterygoid process (via its lateral plate) makes the junction between the maxilla and both the cranial base and the condylar mandibular site of growth.

  2. Influence of surgical sutures on wound healing

    Directory of Open Access Journals (Sweden)

    Mirković 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.

  3. Mesenchymal stem cell-coated sutures enhance collagen depositions in sutured tissues.

    Science.gov (United States)

    Casado, Javier G; Blazquez, Rebeca; Jorge, Inmaculada; Alvarez, Veronica; Gomez-Mauricio, Guadalupe; Ortega-Muñoz, Mariano; Vazquez, Jesus; Sanchez-Margallo, Francisco M

    2014-01-01

    Sutures are commonly used for surgical procedures and new sutures are being developed to improve wound healing. In the past decade, it has been extensively shown that mesenchymal stem cells (MSCs) have a wound healing potential. To benefit the overall wound healing process, we aimed to analyze the usage of pretreated sutures for improving the implantation of MSCs in the tissues. Our results firstly showed that suture pretreatments with gelatin, poly-L-lysine, and NaOH improved the adhesive strength of MSCs to sutures. These cells remained surrounding the sutured tissue and no significant phenotypic changes were found in those cells cultured onto pretreated sutures. In vivo experiments showed that the implantation of MSCs by suturing increases the collagen content in the sutured tissue. Moreover, proteomics analysis of secreted proteins showed that collagen alpha-1(I) chain was the most abundant collagen found. To our knowledge, this is the first report that aimed to improve the implantation of MSCs in tissue by suture pretreatments. Moreover, in vivo experiments suggest that MSC-coated sutures may enhance wound healing and tissue remodeling through the release of different collagen types being applicable for those patients that tend to have difficulty healing.

  4. Woodflour as Reinforcement of Polypropylene

    Directory of Open Access Journals (Sweden)

    José Cláudio Caraschi

    2002-10-01

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

  5. New adjustable suture technique for trabeculectomy

    Directory of Open Access Journals (Sweden)

    Vespasiano Rebouças-Santos

    2013-06-01

    Full Text Available PURPOSE: To describe an adjustable suture (AS experimental model that allows for tightening, loosening and retightening of the suture tension in trabeculectomy. METHODS: Standard trabeculectomy was performed in fifteen pig eyeballs. All pig eyes were tested twice: one test with conventional suture in both flap's corners (conventional suture group and another test with a conventional suture at one corner and an adjustable suture in the other corner (AS group. The order in which each test was performed was defined by randomization. Intraocular pressure was measured at three time points: T1 when the knots were tightened; T2 when the AS was loosened or the conventional knot was removed; and T3 when the AS was retightened in the AS group or five minutes after the knot removal in the conventional suture group. RESULTS: The mean Intraocular pressure was similar between the two groups at time point 1 (p=0.97. However, significant Intraocular pressure differences were found between eyes in the conventional and adjustable suture groups at time points 2 (12.6 ± 4.2 vs 16.3 ± 2.3 cmH2O, respectively, p=0.006 and 3 (12.2 ± 4.0 vs 26.4 ± 1.7cmH2O, respectively; p=0.001. While the conventional technique allowed only Intraocular pressure reduction (following the knot removal; T2 and T3, the AS technique allowed both Intraocular pressure reduction (T2 and elevation (T3 through the management (loosening and retightening of the suture. CONCLUSION: This experimental model provides an effective noninvasive postoperative mechanism of suture tension adjustment.

  6. Postoperative washing of sutured wounds

    Directory of Open Access Journals (Sweden)

    Conrad Harrison

    2016-11-01

    Full Text Available A best evidence topic was written according to the structured protocol. The three part question addressed was: [In patients undergoing closure of surgical wounds with sutures] does [keeping the wound dry for the first 48 h after closure] [reduce the incidence of surgical site infections (SSIs]? 4 relevant papers were culled from the literature and appraised. The authors, date, country, population, study type, main outcomes, key results and study weaknesses were tabulated. Current NICE guidelines recommend cleaning surgical wounds with sterile saline only for the first 48 h following skin closure. We found no evidence that washing wounds with tap water during this period increases the incidence of SSIs compared to keeping them dry. Further randomised controlled trials will enable the construction of conclusive systematic reviews and meta-analyses.

  7. Dyeing of Polypropylene Fibers with Vat Dyes

    Institute of Scientific and Technical Information of China (English)

    LIU Hang; ETTERS J. Nolan; LEONAS Karen K

    2006-01-01

    Polypropylene fibers have been extensively used in a variety of products, including carpets and upholstery, due to their non-absorbency, good weather resistance, good resistance to microorganisms and so on. Because of their hydrophobic and highly crystalline nature, those well-established conventional dyeing processes are difficult to apply to unmodified polypropylene. Colors of polypropylene fibers are primarily obtained by mass coloration which has the disadvantages of limited number of colors available and difficulties in inventory control due to the rapidly changing color needs of the market. In this paper, the use of vat dyes to dye polypropylene fabrics is investigated. Seventeen vat dyes were screened and factors influencing uptake of dyes by polypropylene fabrics were studied.

  8. Strength of different meniscus suturing techniques.

    Science.gov (United States)

    Aşik, M; Sener, N; Akpinar, S; Durmaz, H; Göksan, A

    1997-01-01

    We measured and compared the primary stabilities of five different meniscal suturing techniques. The techniques tested were horizontal mattress, vertical mattress, knot-end, vertical, and vertical loop. Twenty bovine medial menisci were cut to simulate peripheral longitudinal tears and repaired with one of the five suture techniques. Then the two parts of the meniscus were pulled using the Instron Tensometer until failure occurred. Knot-end techniques gave inferior results (mean ultimate failure strength 64 +/- 5 N) compared with the other techniques. Vertical mattress failed at 130 +/- 3 N, vertical loop at 128 +/- 4.5 N, horizontal mattress at 98 +/- 5 N and vertical suturing at 136 +/- 2.7 N. This study shows the superior mechanical characteristic of the vertical suturing technique.

  9. 21 CFR 878.4495 - Stainless steel suture.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stainless steel suture. 878.4495 Section 878.4495...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4495 Stainless steel suture. (a) Identification. A stainless steel suture is a needled or unneedled nonabsorbable surgical suture composed of...

  10. 21 CFR 878.5030 - Natural nonabsorbable silk surgical suture.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Natural nonabsorbable silk surgical suture. 878... Natural nonabsorbable silk surgical suture. (a) Identification. Natural nonabsorbable silk surgical suture... Bombycidae. Natural nonabsorbable silk surgical suture is indicated for use in soft tissue...

  11. Frimand Needle Holder Reduces Suturing Time and Surgical Stress When Suturing in Palm Grip.

    Science.gov (United States)

    Frimand Rönnow, Carl-Fredrik; Jeppsson, Bengt; Thorlacius, Henrik

    2016-06-01

    Purpose The Frimand needle holder (FNH) was developed to facilitate palm grip suturing. In the present study, we wanted to examine the impact of the FNH compared with a conventional Hegar-styled needle holder (HSNH) on suture time and surgical stress. Methods Thirty-two surgeons were enrolled and they performed sets of 3 continuous sutures on a polyurethane pad with premarked insert and exit points and the time for suturing was measured. Surgical stress was quantified by having the surgeons to perform 10 release maneuvers with the FNH and the HSNH on a needle attached to a scale. The scale sent 5 values per second to a computer. The first measurement of each series was regarded as the starting weight and all subsequent measurements were either regarded as neutral, pressure or traction. The sum of these measurements represented total surgical stress. Results We found that all surgeons reduced their median suturing time by 16% when using FNH for palm grip suturing with no difference between junior and senior surgeons. Moreover, it was observed that FNH decreased median surgical stress by 62% for all surgeons performing palm grip suturing compared with a conventional HSNH. Conclusion We conclude that the FNH reduces suture time and surgical stress compared with HSNH when performing palm grip suturing. These findings warrant studies in surgical patients in order to evaluate the potential clinical impact of FNH.

  12. Modification of Nanocomposites by Melting Intercalation of Polypropylene in Montmorillonite

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The polypropylene was modified by ultraviolet irradiation.The polypropylene-montmorillonite nanocomposites were prepared by direct melting intercalation of polypropylene powders.The structure of polypropylene,the polyproprlene irradiated, montmorillinote and polypropylene-montmorillonite composites were studied by XRD, IR and DSC. The results show that the PP molecules can are oxidized during ultraviolet irradiation,melt polypropylene can intercalate into montmorillonite layer.As a result,the layered distance (d001) of montmorillonite increases, and the melt absorption peak of polypropylene in layer is eliminated.

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

    Science.gov (United States)

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

    2015-09-01

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

  14. The hidden X suture: a technical note on a novel suture technique for alveolar ridge preservation

    Science.gov (United States)

    2016-01-01

    Purpose The present study investigated the impact of 2 different suture techniques, the conventional crossed mattress suture (X suture) and the novel hidden X suture, for alveolar ridge preservation (ARP) with an open healing approach. Methods This study was a prospective randomized controlled clinical trial. Fourteen patients requiring extraction of the maxillary or mandibular posterior teeth were enrolled and allocated into 2 groups. After extraction, demineralized bovine bone matrix mixed with 10% collagen (DBBM-C) was grafted and the socket was covered by porcine collagen membrane in a double-layer fashion. No attempt to obtain primary closure was made. The hidden X suture and conventional X suture techniques were performed in the test and control groups, respectively. Cone-beam computed tomographic (CBCT) images were taken immediately after the graft procedure and before implant surgery 4 months later. Additionally, the change in the mucogingival junction (MGJ) position was measured and was compared after extraction, after suturing, and 4 months after the operation. Results All sites healed without any complications. Clinical evaluations showed that the MGJ line shifted to the lingual side immediately after the application of the X suture by 1.56±0.90 mm in the control group, while the application of the hidden X suture rather pushed the MGJ line slightly to the buccal side by 0.25±0.66 mm. It was demonstrated that the amount of keratinized tissue (KT) preserved on the buccal side was significantly greater in the hidden X suture group 4 months after the procedure (Pclinical and radiographic verification of the efficacy of the hidden X suture in preserving the width of KT and the dimensions of the alveolar ridge after ARP. PMID:28050319

  15. 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.

  16. Multiaxial yield behaviour of polypropylene

    Directory of Open Access Journals (Sweden)

    Lang R.

    2010-06-01

    Full Text Available In order to characterize the yield behavior of polypropylene as a function of pressure and to verify the applicability of the Drucker-Prager yield function, various tests were conducted to cover a wide range of stress states from uniaxial tension and compression to multiaxial tension and confined compression. Tests were performed below and above the glass transition temperature, to study the combined effect of pressure and temperature. The pressure sensitivity coefficient as an intrinsic material parameter was determined as a function of temperature. Increasing pressure sensitivity values were found with increasing temperature, which can be related to the change in the free volume and thus, to the enhanced molecular mobility. A best-fit Drucker-Prager yield function was applied to the experimental yield stresses and an average error between the predictions and the measurements of 7 % was obtained.

  17. 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.

  18. Laparoscopic sacral suture hysteropexy for uterine prolapse.

    Science.gov (United States)

    Krause, Hannah G; Goh, Judith T W; Sloane, Kate; Higgs, Peta; Carey, Marcus P

    2006-06-01

    This study aims to describe and review a new method of uterine conservation in pelvic reconstruction for women with uterine prolapse. This is a prospective study of women who have undergone laparoscopic sacral suture hysteropexy. Structured questions, visual analogue patient satisfaction score (VAS), and vaginal examination were undertaken. Follow-up was performed by non-surgical reviewers. From July 2001 until August 2003, a total of 81 women underwent laparoscopic sacral suture hysteropexy for uterine prolapse. At a mean of 20.3 months follow-up, 76 women (93.8%) were available for questioning and 57 (70.3%) attended for examination. Sixty-five women (87.8%) had no symptoms of pelvic floor prolapse, 54 women (94.7%) had no objective evidence of uterine prolapse, and 61 women (82.4%) were satisfied with their surgery (VAS > or = 80%). Laparoscopic sacral suture hysteropexy attaches the posterior cervix to the sacral promontory via the right uterosacral ligament. Follow-up data of laparoscopic sacral suture hysteropexy indicate it to be an effective method in the management of uterine prolapse.

  19. Non-suture methods of vascular anastomosis

    NARCIS (Netherlands)

    Zeebregts, CJ; Heijmen, RH; van den Dungen, JJ; van Schilfgaarde, R

    2003-01-01

    Background: The main aim of performing a vascular anastomosis is to achieve maximal patency rates. An important factor to achieve that goal is to minimize damage to the vessel walls. Sutures inevitably induce vascular wall damage, which influences the healing of the anastomosis. Over time, several a

  20. Barbed sutures in general and digestive surgery. Review.

    Science.gov (United States)

    Ferrer-Márquez, Manuel; Belda-Lozano, Ricardo

    2016-02-01

    The appearance of new barbed sutures is an advance in making knots and anastomosis, mainly in laparoscopic surgery, where the majority of the surgeons find themselves limited dealing with these sutures. Through this review we aim to evaluate both the use and the safety of the sutures in General and Laparoscopic Surgery. Barbed sutures seem to ease the procedures improving key aspects such as reproducibility and operative time.

  1. 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.

  2. Biomechanical Dynamics of Cranial Sutures during Simulated Impulsive Loading

    Directory of Open Access Journals (Sweden)

    Z. Q. Zhang

    2015-01-01

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

  3. A COMPARATIVE STUDY BETWEEN SURGICAL OUTCOME OF PATIENT’S OWN BLOOD VS. 10-0 NYLON FOR CONJUNCTIVAL AUTOGRAFTING IN PTERYGIUM EXCISION

    Directory of Open Access Journals (Sweden)

    Ayush Mahendra

    2016-04-01

    Full Text Available CONTEXT (BACKGROUND Pterygium is a frequently occurring progressive ocular surface disorder which is a fleshy triangular wing shaped growth, encroaching from conjunctiva on cornea. Pterygium is frequent in hot, dry, dusty environment and prevalence is 0.3% to 29%. Surgical removal is main treatment for pterygium. The recurrence rate after pterygium surgery varies according to type of surgery. Various surgical modalities tried like simple excision, bare sclera technique, amniotic membrane transplantation and conjunctival autografting. AIM To compare surgical outcome of patient’s own blood Vs 10-0 Nylon for conjunctival autografting in pterygium excision. SETTINGS AND DESIGN It is a prospective randomised interventional control trial, with a sample size of minimum 30 patients in each group studied in a tertiary care hospital from Oct. 2013 to Dec. 2015. METHODS AND MATERIAL Out of 63 patients who underwent pterygium excision, patient’s own blood was used in 32 patients (Group A and 10-0 Nylon suture was used in 31 patients (Group B for conjunctival autografting. All patients were followed up regularly on postoperative day 1, 8, 30, 90 and 180. Variables for postoperative assessment were pain, watering, irritation, redness, graft displacement, graft loss and recurrence. STATISTICAL ANALYSIS Statistical analysis was performed using SPSS 13.0 (SPSS, Chicago. Outcome variables between the two groups were compared using the non-parametric Mann–Whitney U Test. RESULTS The mean surgical time of group B (31.48±6.15 min is significantly high as compared to group A (19.71±5.13 min with p<0.001. The regression analysis revealed that except surgery type, no other variable had significant impact on the duration of surgery. Postoperative symptoms are less in group A as compared to group B. Group B showed two recurrences whereas no recurrence was seen in group A. CONCLUSIONS Conjunctival autografting by patient’s own blood is better than 10-0 Nylon

  4. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Kandimalla, Raghuram; Kalita, Sanjeeb; Choudhury, Bhaswati [Drug discovery laboratory, Institute of Advanced Study in Science and Technology, Guwahati, Assam 781035 (India); Devi, Dipali [Seri biotech laboratory, Institute of Advanced Study in Science and Technology, Guwahati, Assam 781035 (India); Kalita, Dhaneswar [Government Ayurvedic College and Hospital, Jalukbari, Guwahati, Assam 781014 (India); Kalita, Kasturi [Department of Pathology, Hayat Hospital, Guwahati, Assam 781034 (India); Dash, Suvakanta [Girijananda Chowdhury Institute of pharmaceutical science, Azara, Guwahati, Assam 781017 (India); Kotoky, Jibon, E-mail: jkotoky@gmail.com [Drug discovery laboratory, Institute of Advanced Study in Science and Technology, Guwahati, Assam 781035 (India)

    2016-05-01

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

  6. Electret Stability Related to Spherulites in Polypropylene

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  7. Skin tension related to tension reduction sutures.

    Science.gov (United States)

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

    2015-01-01

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

  8. Suture-induced right coronary artery stenosis.

    Science.gov (United States)

    Seltmann, Martin; Achenbach, Stephan; Muschiol, Gerd; Feyrer, Richard

    2010-01-01

    An 82-year-old patient developed right heart failure in the days after surgical aortic valve replacement. Coronary CT angiography showed a high-grade stenosis of the mid-right coronary artery. Adjacent suture material seen on noncontrast CT suggested that the lesion was related to surgical closure of the right atrial cannulation site. Invasive angiography confirmed the stenosis, and percutaneous intervention was successfully performed.

  9. 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.

  10. 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...

  11. 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...

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

    Directory of Open Access Journals (Sweden)

    Kamath B

    2006-01-01

    Full Text Available Stronger flexor tendon repairs facilitate early active motion therapy protocols. Core sutures using looped suture material provide 1 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.

  13. Safety Pin Suture for Management of Atonic Postpartum Hemorrhage

    OpenAIRE

    Zaitoun, Mostafa M.; Mostfa, Ali Abdelhamed M.

    2012-01-01

    Objective. To assess the efficacy of a new suture technique in controlling severe resistant uterine atonic postpartum hemorrhage. Patients and Methods. This is a retrospective observational study that included thirteen women with uterine atony and postpartum bleeding that did not react to usual medical management. All these women underwent compressing vertical suture technique in which the anterior and posterior walls of the uterus were attached so as to compress the uterus. The suture is tra...

  14. Needle Path Planning for Autonomous Robotic Surgical Suturing.

    Science.gov (United States)

    Jackson, Russell C; Cavuşoğlu, M Cenk

    2013-12-31

    This paper develops a path plan for suture needles used with solid tissue volumes in endoscopic surgery. The path trajectory is based on the best practices that are used by surgeons. The path attempts to minimize the interaction forces between the tissue and the needle. Using surgical guides as a basis, two different techniques for driving a suture needle are developed. The two techniques are compared in hardware experiments by robotically driving the suture needle using both of the motion plans.

  15. Visual Measurement of Suture Strain for Robotic Surgery

    Directory of Open Access Journals (Sweden)

    John Martell

    2011-01-01

    Full Text Available Minimally invasive surgical procedures offer advantages of smaller incisions, decreased hospital length of stay, and rapid postoperative recovery to the patient. Surgical robots improve access and visualization intraoperatively and have expanded the indications for minimally invasive procedures. A limitation of the DaVinci surgical robot is a lack of sensory feedback to the operative surgeon. Experienced robotic surgeons use visual interpretation of tissue and suture deformation as a surrogate for tactile feedback. A difficulty encountered during robotic surgery is maintaining adequate suture tension while tying knots or following a running anastomotic suture. Displaying suture strain in real time has potential to decrease the learning curve and improve the performance and safety of robotic surgical procedures. Conventional strain measurement methods involve installation of complex sensors on the robotic instruments. This paper presents a noninvasive video processing-based method to determine strain in surgical sutures. The method accurately calculates strain in suture by processing video from the existing surgical camera, making implementation uncomplicated. The video analysis method was developed and validated using video of suture strain standards on a servohydraulic testing system. The video-based suture strain algorithm is shown capable of measuring suture strains of 0.2% with subpixel resolution and proven reliability under various conditions.

  16. 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.

  17. The Mechanical Properties of Polypropylene Fiber Reinforced Concrete

    Institute of Scientific and Technical Information of China (English)

    LI Bei-xing; CHEN Ming-xiang; CHENG Fang; LIU Lu-ping

    2004-01-01

    The compressive, shear strengths and abrasion-erosion resistance as well as flexural properties of two polypropylene fiber reinforced concretes and the comparison with a steel fiber reinforced concrete were reported.The exprimental results show that a low content of polypropylene fiber (0.91kg/m3 of concrete) slightly decreases the compressive and shear strengths, and appreciably increased the flexural strength, but obviously enhances the toughness index and fracture energy for the concrete with the same mix proportion, consequently it plays a role of anti-cracking and improving toughness in concrete. Moreover, the polypropylene mesh fiber is better than the polypropylene monofilament fiber in improving flexural strength and toughness of concrete, but the two types of polypropylene fibers are inferior to steel fiber. All the polypropylene and steel fibers have no great beneficial effect on the abrasion-erosion resistance of concrete.

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

    Science.gov (United States)

    Muttaqien, Fahdzi; Suprijadi

    2015-04-01

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

  19. The toughening mechanism of rubber particles in polypropylene composite

    Science.gov (United States)

    Shi, L.; Xiao, J. M.

    2017-01-01

    Filling polypropylene materials with rubber particles can effectively increase the toughness of PP material and improve its cushioning properties. In this paper, we used the two kinds of method of the finite element analysis and experiment to study the rubber particles toughening mechanism, got the deformation process of particles when polypropylene material compressed and the yield stress of polypropylene after compression with particles filled or not.

  20. High strain rate behaviour of polypropylene microfoams

    Science.gov (United States)

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

    2012-08-01

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

  1. 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.

  2. Safety pin suture for management of atonic postpartum hemorrhage.

    Science.gov (United States)

    Mostfa, Ali Abdelhamed M; Zaitoun, Mostafa M

    2012-01-01

    Objective. To assess the efficacy of a new suture technique in controlling severe resistant uterine atonic postpartum hemorrhage. Patients and Methods. This is a retrospective observational study that included thirteen women with uterine atony and postpartum bleeding that did not react to usual medical management. All these women underwent compressing vertical suture technique in which the anterior and posterior walls of the uterus were attached so as to compress the uterus. The suture is transfixed at the uterine fundus, thus eliminating the risk of sutures sliding off at the uterine fundus (safety pin suture). Results. safety pin uterine compression suture was a sufficient procedure to stop the bleeding immediately in 92.2% of the women. None of the women developed complications related to the procedure. Conclusion. A new safety pin suture is a simple and effective procedure to control bleeding in patients with treatment-resistant, life-threatening atonic postpartum hemorrhage with the advantage of eliminating the risk of the sutures sliding off at the uterine fundus.

  3. Suture technicians in a children's hospital emergency department.

    Science.gov (United States)

    Apolo, J O; DiCocco, D

    1988-03-01

    A program that employs technicians for suturing lacerations is presented. Careful selection of the candidates, intensive training, and ongoing monitoring of their activities have been major factors in the success of the program. The curriculum of a course for suture technicians and their job description are discussed.

  4. Autoadjustable sutures and modified seldinger technique applied to laparoscopic jejunostomy.

    Science.gov (United States)

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

    2015-02-01

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

  5. What is the significance of tendon suture purchase?

    Science.gov (United States)

    Kim, J B; de Wit, T; Hovius, S E R; McGrouther, D A; Walbeehm, E T

    2009-08-01

    Repairs have been performed on porcine flexor tendons and subjected to tensile stress measurements to determine the effects and mechanism of core suture purchase (the length of the suture bite). Eighty-four pig trotter flexor profundus tendons were divided and repaired using four lengths of core suture purchase (1.33, 1, 0.66 and 0.33 cm) using a double modified Kessler repair (four strands, two knots) with a peripheral epitendinous suture. Tendon purchase was achieved by either bilateral equal purchase lengths or with one tendon purchase at a fixed depth of 1 cm. A separate group of tendons were incubated in blood for 24 hours to simulate the wound environment prior to testing. Tensile tests demonstrated a progressive increase of repair strength with purchase length. With the exception of the 0.33 cm group, video analysis demonstrated the mode of failure as suture failure and not due to suture pullout. Therefore, the increase in breaking strength cannot be attributed to a better grip of the tendon ends, but to the mechanical characteristics of the suture polymer. The tendency for the incubated tendons to fail more consistently by pullout rather than suture failure, particularly in the shorter purchase lengths, emphasises the importance of studying tendon purchase in vivo. The significance of ex vivo mechanical testing should be considered with caution.

  6. Green aqueous surface modification of polypropylene for novel polymer nanocomposites.

    Science.gov (United States)

    Thakur, Vijay Kumar; Vennerberg, Danny; Kessler, Michael R

    2014-06-25

    Polypropylene is one of the most widely used commercial commodity polymers; among many other applications, it is used for electronic and structural applications. Despite its commercial importance, the hydrophobic nature of polypropylene limits its successful application in some fields, in particular for the preparation of polymer nanocomposites. Here, a facile, plasma-assisted, biomimetic, environmentally friendly method was developed to enhance the interfacial interactions in polymer nanocomposites by modifying the surface of polypropylene. Plasma treated polypropylene was surface-modified with polydopamine (PDA) in an aqueous medium without employing other chemicals. The surface modification strategy used here was based on the easy self-polymerization and strong adhesion characteristics of dopamine (DA) under ambient laboratory conditions. The changes in surface characteristics of polypropylene were investigated using FTIR, TGA, and Raman spectroscopy. Subsequently, the surface modified polypropylene was used as the matrix to prepare SiO2-reinforced polymer nanocomposites. These nanocomposites demonstrated superior properties compared to nanocomposites prepared using pristine polypropylene. This simple, environmentally friendly, green method of modifying polypropylene indicated that polydopamine-functionalized polypropylene is a promising material for various high-performance applications.

  7. The Nuclear Network Generator NETGEN v10.0: A Tool for Nuclear Astrophysics

    Science.gov (United States)

    Xu, Y.; Goriely, S.; Jorissen, A.; Takahashi, K.; Arnould, M.

    2011-09-01

    We present an updated release of the Brussels Nuclear Network Generator. NETGEN is a tool to help astrophysicists build nuclear reaction networks by generating tables of rates of light-particle (mostly n, p, α) induced reactions, nucleus-nucleus fusion reactions, and photodisintegrations, as well as β-decays and electron captures on temperature grids specified by the user. Nuclear reaction networks relevant to a large variety of astrophysical situations can be constructed, including Big-Bang nucleosynthesis, stellar hydrostatic and explosive hydrogen-, helium- and later burning phases, as well as the synthesis of heavy nuclides (s-, r-, p-, rp-, α-processes). The latest version, NETGEN v10.0, is available on the ULB-IAA website www.astro.ulb.ac.be/Netgen/form.html.

  8. 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.

  9. Development of Absorbable, Antibiotic-Eluting Sutures for Ophthalmic Surgery

    Science.gov (United States)

    Kashiwabuchi, Fabiana; Parikh, Kunal S.; Omiadze, Revaz; Zhang, Shuming; Luo, Lixia; Patel, Himatkumar V.; Xu, Qingguo; Ensign, Laura M.; Mao, Hai-Quan; Hanes, Justin; McDonnell, Peter J.

    2017-01-01

    Purpose To develop and evaluate an antibiotic-eluting suture for ophthalmic surgery. Methods Wet electrospinning was used to manufacture sutures composed of poly(L-lactide), polyethylene glycol (PEG), and levofloxacin. Size, morphology, and mechanical strength were evaluated via scanning electron microscopy and tensile strength, respectively. In vitro drug release was quantified using high performance liquid chromatography. In vitro suture activity against Staphylococcus epidermidis was investigated through bacterial inhibition studies. Biocompatibility was determined via histological analysis of tissue sections surrounding sutures implanted into Sprague-Dawley rat corneas. Results Sutures manufactured via wet electrospinning were 45.1 ± 7.7 μm in diameter and 0.099 ± 0.007 newtons (N) in breaking strength. The antibiotic release profile demonstrated a burst followed by sustained release for greater than 60 days. Increasing PEG in the polymer formulation, from 1% to 4% by weight, improved drug release without negatively affecting tensile strength. Sutures maintained a bacterial zone of inhibition for at least 1 week in vitro and elicited an in vivo tissue reaction comparable to a nylon suture. Conclusions There is a need for local, postoperative delivery of antibiotics following ophthalmic procedures. Wet electrospinning provides a suitable platform for the development of sutures that meet size requirements for ophthalmic surgery and are capable of sustained drug release; however, tensile strength must be improved prior to clinical use. Translational Relevance No antibiotic-eluting suture exists for ophthalmic surgery. A biocompatible, high strength suture capable of sustained antibiotic release could prevent ocular infection and preclude compliance issues with topical eye drops. PMID:28083445

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

    Directory of Open Access Journals (Sweden)

    Sei Haga

    2014-01-01

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

  11. THE FTIR STUDIES OF PHOTO-OXIDATIVE DEGRADATION OF POLYPROPYLENE

    Institute of Scientific and Technical Information of China (English)

    WEN Zaiqing; HU Xingzhou; SHEN Deyan

    1988-01-01

    The photo-oxidative degradation process of polypropylene film containing iron ions was investigated via FTIR and absorbance substraction technique. It is shown that the iron ions play an important role in the decomposition of hydroperoxide and the increase of the degradation rate of polypropylene film. Theamorphous region of PP film undergoes degradation prior to the crystalline one.

  12. Oxygen Permeability of Polypropylene Containing Polyisobutene with Magnesium Acetate

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The oxygen permeabilities of polypropylene films are reduced by adding a minor percentage of a polyisobutene ionomer. The polyisobutene ionomers were prepared by in situ salt exchange of magnesium acetate with maleated polyisobutenes of commercially available low relative molecular mass. The more polar magnesium salts aided phase separation during crystallization from the molten polypropylene mixture. Scanning electron microscope photographs revealed that the polyisobutene ionomer is largely concentrated in the amorphous regions between the polypropylene spherulites, where the ionomer tends to concentrate during crystallization. The influence of the polyisobutene ionomer on the oxygen permeability of polypropylene was found to be slightly dependent upon the relative molecular mass of the polyisobutene precursor. Under optimum conditions, the oxygen permeability of polypropylene is reduced by 20% with only 1% additive.

  13. Viscoelastic properties of cellular polypropylene ferroelectrets

    Science.gov (United States)

    Gaal, Mate; Bovtun, Viktor; Stark, Wolfgang; Erhard, Anton; Yakymenko, Yuriy; Kreutzbruck, Marc

    2016-03-01

    Viscoelastic properties of cellular polypropylene ferroelectrets (PP FEs) were studied at low frequencies (0.3-33 Hz) by dynamic mechanical analysis and at high frequencies (250 kHz) by laser Doppler vibrometry. Relaxation behavior of the in-plane Young's modulus ( Y11 ' ˜ 1500 MPa at room temperature) was observed and attributed to the viscoelastic response of polypropylene matrix. The out-of-plane Young's modulus is very small ( Y33 ' ≈ 0.1 MPa) at low frequencies, frequency- and stress-dependent, evidencing nonlinear viscoelastic response of PP FEs. The high-frequency mechanical response of PP FEs is shown to be linear viscoelastic with Y33 ' ≈ 0.8 MPa. It is described by thickness vibration mode and modeled as a damped harmonic oscillator with one degree of freedom. Frequency dependence of Y33 * in the large dynamic strain regime is described by the broad Cole-Cole relaxation with a mean frequency in kHz range attributed to the dynamics of the air flow between partially closed air-filled voids in PP FEs. Switching-off the relaxation contribution causes dynamic crossover from the nonlinear viscoelastic regime at low frequencies to the linear viscoelastic regime at high frequencies. In the small strain regime, contribution of the air flow seems to be insignificant and the power-law response, attributed to the mechanics of polypropylene cell walls and closed air voids, dominates in a broad frequency range. Mechanical relaxation caused by the air flow mechanism takes place in the sound and ultrasound frequency range (10 Hz-1 MHz) and, therefore, should be taken into account in ultrasonic applications of the PP FEs deal with strong exciting or receiving signals.

  14. Marangoni effects in aqueous polypropylene glycol foams.

    Science.gov (United States)

    Tan, Su Nee; Fornasiero, Daniel; Sedev, Rossen; Ralston, John

    2005-06-15

    The foam behavior of three polypropylene glycols covering the molecular weight range between 192 and 725 g/mol has been examined. Static and dynamic surface tension data, as well as bubble size distribution and retention time in the foam, were incorporated into a simple model of foam stability. The latter clearly indicates that surface tension differences between the plateau border and lamellar region adjacent to the bubble surface are the dominant factor in controlling foamability, causing liquid flow in the direction opposite to liquid drainage, a process termed the Marangoni effect.

  15. RHEOLOGICAL BEHAVIOR OF KAOLIN TOUGHENED POLYPROPYLENE COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    OU Yuchun; FANG Xiaoping; FENG Yupeng

    1997-01-01

    The relation between the rheological behavior and various interfacial properties of Kaolin rigid particle toughened polypropylene(PP/Kaolin) composites were studied by means of parallel-plate rheometer, melt flow rate apparatus, scanning electron microscopy (SEM) and other testing methods. The results show that addition of interfacial modifier to PP/Kaolin composites is advantageous to homogeneous dispersion of filler in PP matrix,formation of flexible interlayer between Kaolin particles and PP matrix and improvement of the melt processibility of the composites.

  16. Bacterial adhesion to suture material in a contaminated wound model: Comparison of monofilament, braided, and barbed sutures.

    Science.gov (United States)

    Dhom, Jonas; Bloes, Dominik A; Peschel, Andreas; Hofmann, Ulf Krister

    2016-05-21

    Contaminated suture material plays an important role in the physiopathology of surgical site infections. Recently, suture material has been developed characterized by barbs projecting from a monofilament base. Claimed advantages for barbed sutures are a shortened wound closure time and reduced maximum wound tension. It has also been suggested that these sutures would be advantageous microbiologically. The aim of this study was to test the microbiological characteristics of the barbed Quill in comparison to the monofilament Ethilon II and the braided sutures Vicryl and triclosan-coated Vicryl Plus. In our study, sutures were cultivated on color-change agar with Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecium, Escherichia coli, and Pseudomonas aeruginosa and the halo size was measured. In a second study arm with longer cultivation bacterial growth was followed by antibiotic treatment. Ethilon II and Quill showed good comparable results, whereas large halos were found around Vicryl. Vicryl Plus results depended on triclosan sensitivity. After longer bacterial cultivation and antibiotic treatment, halos were up to 3.6 times smaller on Quill than on Vicryl (P <.001), but 1.4 times larger than on Ethilon II (P <.001) regarding S. aureus. Confocal microscopy analysis showed bacterial colonization between the braided filaments on Vicryl and beneath the barbs on Quill. From a microbiological perspective, barbed sutures can be recommended in aseptic surgery, but should only be used carefully in septic surgery. This article is protected by copyright. All rights reserved.

  17. MonoMax Suture: A New Long-Term Absorbable Monofilament Suture Made from Poly-4-Hydroxybutyrate

    Directory of Open Access Journals (Sweden)

    Erich K. Odermatt

    2012-01-01

    Full Text Available A long-term absorbable monofilament suture was developed using poly-4-hydroxybutyrate (P4HB made from a biosynthetically produced homopolymer of the natural metabolite 4-hydroxybutyrate. The suture, called MonoMax, has prolonged strength retention. At 12 weeks, a size 3-0 MonoMax suture retains approximately 50% of its initial tensile strength in vivo and is substantially degraded in one year with minimal tissue reaction. In contrast, PDS II monofilament suture (Ethicon, Inc., Somerville, NJ has no residual strength in vivo after 12 weeks. In vivo, the MonoMax suture is hydrolyzed primarily by bulk hydrolysis, and is then degraded via the Krebs cycle. MonoMax is substantially more compliant than other monofilament sutures, and incorporates an element of elasticity. Its tensile modulus of 0.48 GPa is approximately one-third of the value of the PDS II fiber providing an exceptionally flexible and pliable fiber with excellent knot strength and security. These features are further enhanced by the fiber's elasticity, which also improves knot security and may help prevent wound dehiscence. Because of its performance advantages, this suture may find clinical utility in applications where prolonged strength retention, and greater flexibility are required, particularly in procedures like abdominal wall closure where wound dehiscence is still a significant post-surgical complication.

  18. Midwives conducting perineal repair: The Danish Suture Trial

    DEFF Research Database (Denmark)

    Kindberg, Sara

    2007-01-01

    Midwives conducting perineal repair: The Danish Suture Trial.     Background Suture techniques and materials for repair of 2nd degree perineal lacerations and episiotomies have been tested in several clinical trials. Danish midwives and obstetricians have developed a new, simple and time-efficien......Midwives conducting perineal repair: The Danish Suture Trial.     Background Suture techniques and materials for repair of 2nd degree perineal lacerations and episiotomies have been tested in several clinical trials. Danish midwives and obstetricians have developed a new, simple and time...... assessed day 1-2 and 10 post partum. Secondary outcomes: patient satisfaction with wound healing, need for secondary repair, superficial pain during intercourse.   Data management: Double entry of all data and intention-to-treat analysis.   Results The follow up rate was 97%. Baseline data were evenly...

  19. Preparation and Characterization of Polypropylene / MWCNT Dispersions

    Science.gov (United States)

    Pujari, Saswati; Burghardt, Wesley; Ramanathan, Thillaiyan; Brinson, L. Catherine; Kasimatis, Kosmas; Torkelson, John

    2008-03-01

    Dispersions of multiwall carbon nanotubes in polypropylene are prepared via melt batch mixing and solid-state shear pulverization, and characterized via linear viscoelastic measurements, SEM, polypropylene crystallization kinetics, electrical conductivity and dynamic mechanical analysis. Increasing the intensity or duration of the melt mixing leads to higher dispersion, evidenced by increases in a low-frequency elastic plateau and accelerated PP crystallization kinetics attributed to more effective heterogeneous nucleation. The sample prepared by pulverization exhibits faster crystallization kinetics than any of the melt blended samples, but in contrast shows no measurable low frequency elastic plateau. Electrical conductivity measurements similarly show higher conductivity in melt blended samples. This may be attributable to scission of the nanotubes during pulverization, such that even well dispersed tubes cannot form an entangled network at a given concentration. At the same time, pulverized composites show marked increase in stiffness at low loadings, indicating that tube scission due to pulverization is not catastrophic. Conversely, long mixing times required in melt blending cause substantial thermal degradation of the polymer matrix with a corresponding loss of mechanical properties.

  20. Failure strengths of repair devices versus meniscus suturing techniques

    OpenAIRE

    Asik, Mehmet; Sener, Nadir; Dikici, Fatih; Sen, Cengiz

    2004-01-01

    Objectives: The purpose of this study was to compare the load to failure of different common suturing techniques with that of repair devices. Methods: Seventy-one calf medial menisci were cut to simulate peripheral longitudinal tears and repaired using either one of the two suture techniques or one of the seven repair devices. Then the two parts of the meniscus were pulled using an Instron tensometer until failure occurred. The techniques and repair devices tested included vertical (0 PDS,...

  1. 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.

  2. Evaluating plastic shrinkage and permeability of polypropylene fiber reinforced concrete

    Directory of Open Access Journals (Sweden)

    G.M. Sadiqul Islam

    2016-12-01

    Full Text Available Plastic concrete is susceptible to develop cracks due to shrinkage in dry and windy conditions. Addition of fibers could reduce propagation of this crack. On the other hand, permeability determines the durability properties of concrete. This study evaluated strength, plastic shrinkage and permeability (gas and water of concrete incorporating ‘polypropylene’ fiber (aspect ratio 300 in various proportions (viz. 0.10%, 0.15%, 0.2%, 0.25% and 0.3% by volume of concrete. Plane concrete samples were also prepared and tested for reference purpose. Inclusion of 0.1% fiber gave minor reduction (2% in compressive strength while the tensile strength increased by 39% with same fiber content compared to the plain concrete. A significant reduction in crack generation, appearance period of first crack and crack area between plane concrete and fiber reinforced concretes was found. The experimental result with inclusion of 0.1–0.3% fiber in concrete indicated that plastic shrinkage cracks were reduced by 50–99% compared to the plain concrete. For reference concrete (without fiber, test within the high temperature and controlled humidity chamber gave higher crack width than the acceptable limit (3 mm specified by the ACI 224. With the inclusion of 0.1% fiber reduced the crack width down to 1 mm and the trend was continued with the addition of more fibers. However, results showed that with the addition of polypropylene fiber both water and gas permeability coefficient was increased. Therefore, it is concluded that the fiber reinforced concrete would work better for plastic shrinkage susceptible structural elements (flat elements such as slab; however, it requires careful judgement while applying to a water retaining structures.

  3. 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.

  4. The feasibility study of Polypropylene mesh in pollution incision application%S 聚丙烯网片在污染切口应用的大鼠实验研究

    Institute of Scientific and Technical Information of China (English)

    赵亮; 苏拓; 张杰; 许铮; 刘凤阁; 刘彤; 王秀芳

    2014-01-01

    目的:通过动物实验研究污染伤口植入聚丙烯网片后切口感染率和病理学变化,探讨嵌顿性腹股沟疝患者应用聚丙烯网片行疝修补术的可行性。方法大鼠分成3组,每组40只,分别为清洁植入网片组(A 组)、大肠杆菌污染不植入网片组(B 组)和大肠杆菌污染植入网片组(C 组)。在大鼠左右背部切口3 cm,A 组直接植入聚丙烯网片,B组应用大肠杆菌悬浊液污染切口30 min 后0.25%稀释碘伏冲洗切口后局部用咽拭子浸蘸做细菌培养然后直接缝合,C组如 B 组处理后植入聚丙烯网片。术后观察 A、B、C 三组伤口愈合情况和感染率,并分别于术后1、2、4、8周取出网片作病理检查。结果所有实验动物无死亡。A 组切口1期愈合,切口感染率为0;1周时网片网孔内已有纤维母细胞和纤维细胞增生,部分区域已有肉芽形成,8周时纤维细胞和胶原细胞已经排列规则致密;B、C 组细菌培养无细菌生长;B 组切口感染率7.5%(3/40),感染切口经引流换药2期愈合;C 组切口感染率10.0%(4/40),未感染之网片较清洁切口之网片同期病理有较多巨噬细胞存在;感染切口未去除网片经引流换药2期愈合,术后8周取出网片作病理检查纤维细胞和胶原细胞较规则排列,有巨噬细胞存在。结论动物实验结果表明:切口污染状态下经稀释碘伏冲洗后,植入聚丙烯网片并不增加切口感染率。提示对于嵌顿性腹股沟疝甚至发生肠坏死行肠切除肠吻合患者可以应用聚丙烯网片行疝修补术。%Objective To study contaminated wounds after implantation of polypropylene mesh in the incision by observing infection rate and pathology change,and to investigate the application feasibility of line polypropylene mesh hernia repair on patients with incarcerated inguinal hernia. Methods New Zealand rabbit is divided into three groups

  5. LONG TERM OUTCOME AFTER OPEN INGUINAL HERNIA REPAIR BY CONTINOUS SUTURE VERSUS INTERRUPTED SUTURE TO FIX THE MESH

    Directory of Open Access Journals (Sweden)

    Kuldeep Raj

    2013-12-01

    Full Text Available ABSTRACT : BACK GROUND: Meshplasty is a must in adult patient. P ro lene mesh is widely used and is fixed with prolene suture as well. The aim of this study was to compare the quality of life and pain felt in postoperative phase for 2 years after open inguinal hernia repair by i nterrupted sutures versus continous sutures. METHODS: From Jan 2010 – Dec 2010 , 15 patients were operated using prolene mesh and this mesh was fixed with prolene 2’0’ in continous way starting at pubic tubercle and continues along inguinal ligament beyond deep inguinal r ing and then lateral to deep inguinal ring and above it along conjoint tendon and ends at the pubic tubercle with only single knot , and were compared with 15 patients who underwent same procedure using prolene mesh fixed with p rolene suture but in interrupted way and this creates a lot of knots ( 10 - 12 Av erage . Patients were examined and followed in OPD for 2 years. RESULTS : In the long run the patients treated with continous suture were having comparatively better qua lity of life with less pain and less foreign body sensation of mesh and knots & knots were not felt percutaneously, where as in routine procedure patients were complaining of painful sensation due to pressing of knots in subcutaneous space. CONCLUSION : In this study the quality of life in open hernia repair with prolene suture using continous suture technique versus interrupted suture technique is definitely better , less pain ful and feeling less foreign body sensation.

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

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, J.; Albano, C.; Davidson, E.; Poleo, R. [Universidad Central de Venezuela, Caracas (Venezuela). Escuela de Quimica; Gonzalez, J.; Ichazo, M. [Universidad Simon Bolivar, Dept. de Mecanica, Caracas (Venezuela); Chipara, M. [Research Institute for Electrotechnics, Bucharest (Romania)

    2001-04-01

    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.)

  7. Mechanical Properties of Isotactic Polypropylene Modified with Thermoplastic Potato Starch

    Science.gov (United States)

    Knitter, M.; Dobrzyńska-Mizera, M.

    2015-05-01

    In this paper selected mechanical properties of isotactic polypropylene (iPP) modified with potato starch have been presented. Thermoplastic starch (TPS) used as a modifier in the study was produced from potato starch modified with glycerol. Isotactic polypropylene/thermoplastic potato starch composites (iPP/TPS) that contained 10, 30, 50 wt.% of modified starch were examined using dynamic mechanical-thermal analysis, static tensile, Brinell hardness, and Charpy impact test. The studies indicated a distinct influence of a filler content on the mechanical properties of composites in comparison with non-modified polypropylene.

  8. Synthesis and characterization of novel polypropylene paper releasing anlon

    Institute of Scientific and Technical Information of China (English)

    Li Qiu Wang; Qing Shan Li; Hui Peng Ma; Xiao Feng Guo; Rui Hong Wang; Gang Yao

    2009-01-01

    Polypropylene synthetic paper releasing anion was prepared from polypropylene resin,anion additives,titanium dioxide,etc.,by calendar forming method.The synthetic paper was tested by anion detector,SEM,AFM,etc.Tensile strength,elongation at break,right angle tear strength of the polypropylene synthetic paper reached the GB 13022 or QB,1r/T130 Standard.The synthetic paper was water and oil resistance.and released anions 10,530 cm-3.It Was environment-fendy.and a kind of good material for human'S health.

  9. Effects of COOH+ ion implantation on hemocompatibility of polypropylene

    Institute of Scientific and Technical Information of China (English)

    LI; Dejun(李德军); NIU; Lifang(牛丽芳)

    2002-01-01

    Carboxyl ion (COOH+) implantation was performed at 50 keV with different fluences for polypropylene. Hemocompatibility tests show that blood coagulation time and recalcification time of polypropylene were enhanced significantly with the increasing fluence. At the same time, the human endothelial cells grown on the surface of the implanted samples exhibited normal cellular growth and morphology. X-ray photoelectron spectroscopy and water contact angle analysis showed that COOH+ ion implantation rearranges chemical bonds and produces some new polar O-containing groups on the surface. The formation of polar functional groups, together with increase of roughness, induced an increase in hydrophilicity, which in turn improved the surface hemocompatibility of polypropylene.

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

    Directory of Open Access Journals (Sweden)

    Bjorn eBehr

    2011-07-01

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

  11. Craniosynostosis of coronal suture in twist1 mice occurs through endochondral ossification recapitulating the physiological closure of posterior frontal suture.

    Science.gov (United States)

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

    2011-01-01

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

  12. 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.

  13. Determination of Partition Coefficients of Selected Model Migrants between Polyethylene and Polypropylene and Nanocomposite Polypropylene

    Directory of Open Access Journals (Sweden)

    Pablo Otero-Pazos

    2016-01-01

    Full Text Available Studies on nanoparticles have focused the attention of the researchers because they can produce nanocomposites that exhibit unexpected hybrid properties. Polymeric materials are commonly used in food packaging, but from the standpoint of food safety, one of the main concerns on the use of these materials is the potential migration of low molecular substances from the packaging into the food. The key parameters of this phenomenon are the diffusion and partition coefficients. Studies on migration from food packaging with nanomaterials are very scarce. This study is focused on the determination of partition coefficients of different model migrants between the low-density polyethylene (LDPE and polypropylene (PP and between LDPE and nanocomposite polypropylene (naPP. The results show that the incorporation of nanoparticles in polypropylene increases the mass transport of model migrants from LDPE to naPP. This quantity of migrants absorbed into PP and naPP depends partially on the nature of the polymer and slightly on the chemical features of the migrant. Relation (RPP/naPP between partition coefficient KLDPE/PP and partition coefficient KLDPE/naPP at 60°C and 80°C shows that only BHT at 60°C has a RPP/naPP less than 1. On the other hand, bisphenol A has the highest RPP/naPP with approximately 50 times more.

  14. Usefulness of Titanized Polypropylene Mesh and an Anchor System for Correction of Lower Lid Retraction.

    Science.gov (United States)

    Iida, Naoshige; Watanabe, Ayako

    2016-02-01

    Because of the lower eyelid's free edge anatomy, it is difficult to preserve its contours after reconstruction. We recently attempted a new operative procedure to treat 2 cases of lower lid retraction by using a titanized polypropylene mesh and an anchor system. As the lower lid skin is elevated laterally in an oblique upward direction, the location of the mesh insertion is decided and the site is marked accordingly. The mesh to be inserted is approximately 20 × 10 mm. A skin incision is rendered from the medial to the lateral side of the lower eyelid edge, and the line of incision is raised beyond the lateral canthus along the skinfold. The mesh insertion site is then developed in the deep fat layer. After hemostasis, the mesh is densely sutured with the fat tissue. Next, the lateral orbital rim is exposed under the periosteum, and 2 anchors, each 2 mm in diameter, are driven into place. The thread connected to each anchor is passed through the mesh and subcutaneous tissue and placed in the lateral orbital rim. Excess skin is trimmed, and the wound is closed. Both patients had complained of dry eye and lacrimation before treatment. No postoperative complications were observed, and in both cases, the symptoms disappeared, and the patient's appearance was improved. During the follow-up period, which lasted from 15 to 29 months, elevation of the lower eyelid edge was kept at a favorable level, and neither case exhibited a relapse of retraction.

  15. 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.

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

    Institute of Scientific and Technical Information of China (English)

    BoDong Lv; ShiGeng Zhang; XuanWen Zhu; Jie Zhang; Gang Chen; MinFu Chen; HongLiang Shen; ZaiJun Pei; ZhaoDian Chen

    2014-01-01

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

  17. Dynamic indentation on layered polypropylene foams

    Science.gov (United States)

    Maheo, L.; Viot, P.

    2012-08-01

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

  18. Flexural creep behaviour of jute polypropylene composites

    Science.gov (United States)

    Chandekar, Harichandra; Chaudhari, Vikas

    2016-09-01

    Present study is about the flexural creep behaviour of jute fabric reinforced polypropylene (Jute-PP) composites. The PP sheet and alkali treated jute fabric is stacked alternately and hot pressed in compression molding machine to get Jute-PP composite laminate. The flexural creep study is carried out on dynamic mechanical analyzer. The creep behaviour of the composite is modeled using four-parameter Burgers model. Short-term accelerated creep testing is conducted which is later used to predict long term creep behaviour. The feasibility of the construction of a master curve using the time-temperature superposition (TTS) principle to predict long term creep behavior of unreinforced PP and Jute-PP composite is investigated.

  19. 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.

  20. Dynamic indentation on layered polypropylene foams

    Directory of Open Access Journals (Sweden)

    Viot P.

    2012-08-01

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

  1. Flexural Strength and Behavior of Polypropylene Fiber Reinforced Concrete Beams

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The strength and deformation characteristics of polypropylene fiber reinforced concrete (PFRC) beams were investigated by four-point bending procedures in this paper.Two kinds of polypropylene fibers with different fiber contents (0.2%, 0.5%, 1.0% and 1.5%) by volume were used in the beam, which measured 100×100 mm with a span of 300 mm.It was found that the strength of the reinforced concrete beams was significantly decreased,whereas the flexural toughness was improved,compared to those unreinforced concrete beams.Geometry properties and volume contents of polypropylene fiber were considered to be important factors for improving the flexural toughness.Moreover,the composite mechanism between polypropylene fiber and concrete was analyzed and discussed.

  2. 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.

  3. Quantitative evaluation of midpalatal suture maturation via fractal analysis

    Science.gov (United States)

    Kwak, Kyoung Ho; Kim, Yong-Il; Kim, Yong-Deok

    2016-01-01

    Objective The purpose of this study was to determine whether the results of fractal analysis can be used as criteria for midpalatal suture maturation evaluation. Methods The study included 131 subjects aged over 18 years of age (range 18.1–53.4 years) who underwent cone-beam computed tomography. Skeletonized images of the midpalatal suture were obtained via image processing software and used to calculate fractal dimensions. Correlations between maturation stage and fractal dimensions were calculated using Spearman's correlation coefficient. Optimal fractal dimension cut-off values were determined using a receiver operating characteristic curve. Results The distribution of maturation stages of the midpalatal suture according to the cervical vertebrae maturation index was highly variable, and there was a strong negative correlation between maturation stage and fractal dimension (−0.623, p Fractal dimension was a statistically significant indicator of dichotomous results with regard to maturation stage (area under curve = 0.794, p fractal dimension was used to predict the resulting variable that splits maturation stages into ABC and D or E yielded an optimal fractal dimension cut-off value of 1.0235. Conclusions There was a strong negative correlation between fractal dimension and midpalatal suture maturation. Fractal analysis is an objective quantitative method, and therefore we suggest that it may be useful for the evaluation of midpalatal suture maturation. PMID:27668195

  4. Failure strength of repair devices versus meniscus suturing techniques.

    Science.gov (United States)

    Aşík, Mehmet; Sener, Nadir

    2002-01-01

    The purpose of this study was to compare the load to failure of different common suturing techniques with repair devices. Seventy-one calf medial menisci were cut to simulate peripheral longitudinal tears and repaired with one of 13 repair techniques. The two parts of the meniscus were pulled using the Instron tensometer until failure occurred. The techniques and repair devices tested were vertical (0 PDS, 2-0 PDS, 2-0 Ethibond), horizontal (0 PDS, 2-0 PDS, 2-0 Ethibond) suturing, T-fix, Mitek, Clearfix screw, Clearfix dart, Biostinger, S-D-sorb, and Artrex dart. The strongest repair method in our study was the vertical sutures with 0 PDS. In this study the mean failure strength of all meniscal repair devices was lower than that of the vertical and horizontal suturing techniques. All meniscus repair devices except T-fix and in some the Arthrex dart (40% broken up) pulled out of the menisci. Devices which had only horizontally placed barbs had lower mean failure strength. Failure strength of T-fix was similar to horizontal sutures with 2-0 Ethibond and 2-0 PDS. In conclusion, because all meniscal repair devices had inferior results, when such devices are used, postoperative rehabilitation should not be hastened, and their inferior primary stability should be kept in mind.

  5. Biomechanical Study of Two Peripheral Suture Methods on Repaired Tendons

    Science.gov (United States)

    Qiu, Zhenling

    2015-01-01

    Flexor digitorum tendon injuries are challenging conditions to manage to ensure optimal patient outcomes. While several surgical approaches with high success rates have been developed, there remains no gold standard for suture technique for the repair of flexor tendon injuries. In this study, we compared two distinct peripheral suture methods on the strength of repaired tendons. Pig flexor digitorum profundus tendons were used in biomechanical studies and the biomechanical influence on tendon repair of continuous running peripheral suture (CRPS) and continuous locking peripheral suture (CLPS), were compared, using stitch length ranging from 1mm to 5mm. In CRPS, the 1mm stitch length group displayed the highest maximum load and breaking power, which was 1.57 fold higher than the 2mm stitch length group. Pairwise comparison revealed that the 1 and 2mm groups were statistically different from the 3, 4, and 5mm stitch length groups while comparison among the latter groups was not statistically significant. For CLPS, the 1mm group exhibited consistently the highest maximum load strength and breaking power, which was twice the strength displayed by the 2mm group. Pairwise comparisons between groups showed statistical significance. For future repairs of flexor tendon injuries, 1mm stitch length is highly recommended for simple peripheral suture.

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

    Directory of Open Access Journals (Sweden)

    Hamid Bigdelian

    2014-03-01

    Full Text Available 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.Methods: During 2 years period, 620 patients who underwent median sternotomy were studied. The efficacy of absorbable polydioxanone suture was tested on patients using figure-of-eight suture technique. The patients’ age ranged from newborn to 15 years old. All surgical interventions were performed according to a standard protocol.Results: No sternal sutures were broken during the sternal closure and no case of mediastinitis was seen. Two patients experienced sternal dehiscence (0.32%. Follow-up period of patients were established between 1 to 132 months after open heart surgery.Conclusion: Sternal closure with the polydioxanone suture in combination with figure-of-eight technique is a safe and suitable method in children with good clinical results.

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

    Science.gov (United States)

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

    2014-03-01

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

  8. A comparative study of the effect of suture-less and multiple suture techniques on inflammatory complications following third molar surgery.

    Science.gov (United States)

    Osunde, O D; Adebola, R A; Saheeb, B D

    2012-10-01

    The aim of this prospective randomized study was to evaluate the effect of not using sutures on postoperative pain, swelling and trismus after lower third molar surgery. 80 patients with impacted lower third molars were referred for surgical extraction (42 males; 38 females; aged 18-38 years). The patients were randomly divided into two equal groups (sutures n=40; suture-less n=40). In the experimental group, the flaps were replaced without suturing. The control group was selected using the same criteria and treated under the same surgical protocol as the experimental group, except that the flaps were apposed using multiple sutures. Pain, swelling and trismus were evaluated at 24 h, 48 h and 1 week postoperatively in both groups. The operation time was found to be significantly longer in the multiple sutures group (p0.05). There is less postoperative pain, swelling and trismus with the suture-less technique in third molar surgery.

  9. Flow-induced crystallization in isotactic polypropylene

    Science.gov (United States)

    Hamad, Fawzi Ghassan

    Brief intervals of strong flow stretch chains in a semicrystalline polymer melt, which results in an increase in the nuclei number density and a transformation of the crystal structure. This flow-induced crystallization (FIC) phenomenon is explored in this study using highly isotactic polypropylene (iPP) samples. Using one synthesized and five commercial linear isotactic polypropylene samples, we investigate the FIC behavior by imposing shear onto these samples in a rotational rheometer. Equipped with a good temperature control and flexible shear protocol, we apply different temperature and flow conditions. The magnitude of the FIC effect varies with basic processing parameters (shear rate, specific work, crystallization temperature, and shearing temperature) and material properties (totalistic, molecular weight distribution, and particle concentration in the polymer). The scope of this study is to systematically investigate the influences of these parameters on FIC. The FIC effects that are investigated in this dissertation are: crystallization kinetics, persistence time of flow-induced nuclei, and crystal morphology. The crystallization time was measured in the rheometer by monitoring the onset of crystallization after quenching samples sheared above Tm. These samples were subsequently used to study their flow-induced nuclei persistence time and crystal morphology. The lifetime of flow-induced nuclei was determined by measuring the time required to return from FIC back to quiescent crystallization using a differential scanning calorimeter. The crystal morphology was imaged using polarized optical microscopy and atomic force microscopy. We investigated the influence of specific work on the three FIC characteristics, and found three regimes that are separated by the critical work ( Wc) and the saturation work (Wsat) thresholds. Below the critical work threshold, the morphology is composed of mostly spherulite crystals, which keep a constant volume, and a small

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

    Directory of Open Access Journals (Sweden)

    Elif Sarı

    2014-12-01

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

  11. Nanostructured Antibacterial Silver Deposited on Polypropylene Nonwovens

    Science.gov (United States)

    Hong-Bo, Wang; Jin-Yan, Wang; Qu-Fu, Wei; Jian-Han, Hong; Xiao-Yan, Zhao

    Nanostructured silver films were deposited on polypropylene (PP) nonwovens by RF magnetron sputter coating to obtain the antibacterial properties. Shake flask test was used to evaluate the antibacterial properties of the materials. Atomic force microscope (AFM) was utilized to observe the surface morphology. Energy-dispersive X-ray (EDX) was also employed to analyze the surface elemental compositions. The antibacterial results indicated that the prolonged deposition time led to a significant improvement in antibacterial effect, and sputtering power and argon pressure did not show obvious effect on antibacterial performance. It is believed that the total amount of silver ions released from the silver coating was increased as the deposition time increased. AFM images and quantitative analysis of EDX, respectively revealed that increase in deposition time led to the increased coverage of silver film and the increased silver weight percentage per unit surface, which provided evidences for the increased release rate of silver ions from the coating. Moreover, it was found that the optimum silver coating thickness was about 3 nm, taking antibacterial effect and cost of production into account.

  12. 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.

  13. Optical properties of polypropylene upon recycling.

    Science.gov (United States)

    De Santis, Felice; Pantani, Roberto

    2013-01-01

    In the last few years there has been an increasing interest in the possibility of recycling polymeric materials, using physical recycling. However, is it well known that polymers experience a depletion of all the properties upon recycling. These effects have been widely characterized in the literature for what concerns the mechanical or rheological properties. The changes of optical properties after recycling have been much less studied, even if, especially in food packaging, optical characteristics (above all the opacity) are of extreme importance, and thus it is quite significant to assess the effect of recycling on these properties. In this work, the influence of recycling steps on the opacity of films of a commercial grade of isotactic polypropylene (i-PP) was studied. The material was extruded several times to mimic the effect of recycling procedures. After extrusion, films were obtained by cooling samples of material at different cooling rates. The opacity of the obtained films was then measured and related to their crystallinity and morphology. It was found that opacity generally increases on increasing the amount of α phase and for the same amount of α phase on increasing the size of the spherulites.

  14. On Crystallization in Polypropylene-Polyethylene Blends

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Blends of polypropylene(PP) and low-density polyethylene (LDPE) have beencrystallized to form open structures(“cluster spherulites”) where the droplets of the minorityPP are bridged by PP lamellae which have grown in the LDPE-rich matrix. These are studiedby permanganic etching followed by electron and optical microscopies. Two similar PP typesare compared, one synthesized with Ziegler-Natta catalyst and one with metallocenecatalyst. The metallocene-catalysed material crystallized much more slowly due to thepresence of regio defects in the chains, even though the overall concentration of tacticitydefects in the Ziegler-Natta material is much higher. A mechanism involving reversal ofhelical direction at the regio defect interfering with the regular chain packing in the crystal issuggested. Growth of “cluster spherulites” is faster in regions where low molecular weightmaterial is concentrated. It is slower where droplets are larger, and this is attributed tocompetition between PP lamellar growth in the matrix and diffusion of PP to alreadycrystallized droplets.

  15. 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 (σ~28 MPa compared to the untreated fibers composite (σ~22 MPa or alkali treatment (σ~24 MPa. However, CMUV composites containing 10 vol. (% fiber presented best results for the electrical tracking test and electrical resistivity (3 × 10(7 Ω.m. The results suggest that composites reinforced with mechanically treated coconut fibers are suitable for electrical applications.

  16. Microwave Irradiation on Halloysite-Polypropylene Nanocomposites

    Science.gov (United States)

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

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

  17. Radiation Effects on Polypropylene Carbon Nanofibers

    Science.gov (United States)

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

    2010-03-01

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

  18. 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.

  19. Optical Properties of Polypropylene upon Recycling

    Directory of Open Access Journals (Sweden)

    Felice De Santis

    2013-01-01

    Full Text Available In the last few years there has been an increasing interest in the possibility of recycling polymeric materials, using physical recycling. However, is it well known that polymers experience a depletion of all the properties upon recycling. These effects have been widely characterized in the literature for what concerns the mechanical or rheological properties. The changes of optical properties after recycling have been much less studied, even if, especially in food packaging, optical characteristics (above all the opacity are of extreme importance, and thus it is quite significant to assess the effect of recycling on these properties. In this work, the influence of recycling steps on the opacity of films of a commercial grade of isotactic polypropylene (i-PP was studied. The material was extruded several times to mimic the effect of recycling procedures. After extrusion, films were obtained by cooling samples of material at different cooling rates. The opacity of the obtained films was then measured and related to their crystallinity and morphology. It was found that opacity generally increases on increasing the amount of α phase and for the same amount of α phase on increasing the size of the spherulites.

  20. THERMAL properties and morphology of Polypropylene/Polycarbonate/Polypropylene-Graft-Maleic anhydride blends

    Directory of Open Access Journals (Sweden)

    Mat-Shayuti M. S.

    2016-01-01

    Full Text Available This work investigates the effect of blending polycarbonate (PC into polypropylene (PP matrix polymer on thermal properties and morphology. The blends, containing 5% to 35% of polycarbonate and 5% compatibilizer, were compounded using twin-screw extruder and fabricated into standard tests samples using injection or compression molding. The compatibilizer used was polypropylene-graft-maleic anhydride (PP-g-MA. Thermogravimetric analysis (TGA showed improved thermal degradation temperature of PP/PC/PP-g-MA blends compared to pure PP. As PC content increased, the thermal degradation temperature also improved. The highest improvement of thermal degradation temperature was 23.3%, demonstrated by 60/35/5 composition. It was found that the thermal stability of PP/PC blends was improved with the addition of PP-g-MA. PP-g-MA was suspected to enhance the phase adhesion between PP and PC, thus improving thermal stability. Microscopy analysis showed PC reinforcement phase existed as particulates dispersed in PP matrix phase. PC also was in irregular shapes of fibers or flakes in certain compositions, depending on PC fraction and compatibilizer content.

  1. Influence of Morphology on Electrical Properties of Syndiotactic Polypropylene Compared with Those of Isotactic Polypropylene

    Science.gov (United States)

    Kim, Dong; Yoshino, Katsumi; Inoue, Takeo; Abe, Masaru; Uchikawa, Nobutaka

    1999-06-01

    The influence of morphology on the electrical properties of syndiotactic polypropylene (sPP) has been investigated in comparison with those of conventional isotactic polypropylene (iPP). The evolution of spherulite in sPP occurred at a lower temperature than in iPP, and the size of spherulites in sPP is much smaller than those of iPP, though the number of spherulites increases drastically. The influence of heat treatment on the electrical properties of sPP, such as conductivity and current density-electric field characteristics, is negligible in contrast to iPP, in which the conductivity increased drastically and breakdown strength decreased markedly due to growth of large spherulites upon heat treatment. These results are discussed in terms of morphological change upon heat treatment. As a result, sPP is confirmed to be an excellent candidate for a new insulating polymer for cables which can be used at a much higher operating temperature than that of widely used cables with cross-linked polyethylene (XLPE) (90°C), because of its thermal stability, stable electrical properties even following heating treatment and mechanical flexibility due to the small spherulite size and low crystallinity under any preparation and treatment conditions.

  2. Cranial suture biology and dental development: genetic and clinical perspectives.

    Science.gov (United States)

    De Coster, P J; Mortier, G; Marks, L A; Martens, L C

    2007-09-01

    Premature fusion of the calvarial bones at the sutures, or craniosynostosis (CS), is a relatively common birth defect (1:2000-3000) frequently associated with limb deformity. Patients with CS may present oral defects, such as cleft soft palate, hypodontia, hyperdontia, and delayed tooth eruption, but also unusual associations of major dental anomalies such as taurodontism, microdontia, multiple dens invaginatus, and dentin dysplasia. The list of genes that are involved in CS includes those coding for the different fibroblast growth factor receptors and a ligand of ephrin receptors, but also genes encoding transcription factors, such as MSX2 and TWIST. Most of these genes are equally involved in odontogenesis, providing a pausible explanation for clinical associations of CS with dental agenesis or tooth malformations. On the basis of the present knowledge on genes and transcription factors that are involved in craniofacial morphogenesis, and from dental clinics of CS syndromes, the molecular mechanisms that control suture formation and suture closure are expected to play key roles in patterning events and development of teeth. The purpose of this article is to review and merge the recent advances in the field of suture research at the genetic and cellular levels with those of tooth development, and to apply them to the dental clinics of CS syndromes. These new perspectives and future challenges in the field of both dental clinics and molecular genetics, more in particular the identification of possible candidate genes involved in both CS and dental defects, are discussed.

  3. Functional influence on sutural bone apposition in the growing rat.

    NARCIS (Netherlands)

    Katsaros, C.; Zissis, A.; Bresin, A.; Kiliaridis, S.

    2006-01-01

    INTRODUCTION: The aim of this study was to quantify the influence of reduced masticatory muscle function on sutural bone apposition in the growing rat. METHODS: Twenty-six growing male albino rats were randomly divided into 2 equal groups; 1 (hard-diet group) received the ordinary diet of hard pelle

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

    Directory of Open Access Journals (Sweden)

    Bhatti S

    1996-01-01

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

  5. Hyperammonemic encephalopathy due to suture line breakdown after bladder operation.

    Science.gov (United States)

    Boogerd, W; Zoetmulder, F A; Moffie, D

    1990-01-01

    A patient is described with a severe encephalopathy and hyperammonemia in absence of liver dysfunction, attributed to urine absorption into the systemic circulation due to suture line breakdown after bladder dome resection. At autopsy characteristic Alzheimer type II astrocytes were found in the basal ganglia.

  6. Automatic Detection of Wild-type Mouse Cranial Sutures

    DEFF Research Database (Denmark)

    Ólafsdóttir, Hildur; Darvann, Tron Andre; Hermann, Nuno V.;

    , automatic detection of the cranial sutures becomes important. We have previously built a craniofacial, wild-type mouse atlas from a set of 10 Micro CT scans using a B-spline-based nonrigid registration method by Rueckert et al. Subsequently, all volumes were registered nonrigidly to the atlas. Using...

  7. MERSILENE (POLYESTER), A NEW SUTURE FOR PENETRATING KERATOPLASTY

    NARCIS (Netherlands)

    RAMSELAAR, JAM; BEEKHUIS, WH; RIJNEVELD, WJ; VANANDEL, MV; DIJK, F; JONGEBLOED, WL

    1992-01-01

    Mersilene (polyester monofilament) seems to be suitable for penetrating keratoplasty because it is strong, shows no degradation by ultraviolet light, is insoluble, so that it can be left in situ, and offers the possibility of regulating postoperative astigmatism by suture adjustment. In 12 patients

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

    Directory of Open Access Journals (Sweden)

    Krkić 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.

  9. Laser hole drilling in thick polypropylene sheets for alignment sensors

    Science.gov (United States)

    Bergen, D. E.; Chapman, Glenn H.; Samra, Taranjit S.; Weeks, T. S.

    1996-04-01

    Laser micromachining of polypropylene for transducer applications has the advantage of creating small ( 400 micron). Normally translucent polypropylene formed using carbon as a dye is an excellent laser machining material having a high optical absorption, and a low thermal conductivity. For an optical alignment system a matrix of high aspect ratio holes of 400 micron) sheets. This alignment sensor is to be used on the end of a robot arm and will aid in the manipulation of the arm. Using an argon ion laser focused through a 50 mm lens (5.2 micron R1/e2 spot, 55.2 micron focal depth), holes as small as 30 microns on 150 micron spacing were achieved in 400 - 500 micron thick black polypropylene sheets with consistent results. Best results currently are achieved with a laser power of only 0.3 W, using 10 - 100 pulse stream of 10 - 100 microsec pulses, and duty cycles of polypropylene required 17 times the power, and achieved holes of only 127 microns, with 500 microns spacing in 500 micron thick material. Thicker (1 mm) black polypropylene produces 144 micron holes on 500 micron spacings due to the lip material, and required a 100 mm lens.

  10. Production of high melt strength polypropylene by gamma irradiation

    Science.gov (United States)

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

    2007-11-01

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

  11. REACTION OF THE RABBIT CORNEAL ENDOTHELIUM TO NYLON SUTURES - A SEM STUDY

    NARCIS (Netherlands)

    JONGEBLOED, WL; VANDERVEEN, G; KALICHARAN, D; RIJNEVELD, WJ; HOUTMAN, WA; WORST, JGF

    1990-01-01

    Nylon and stainless steel sutures separately placed deeply into rabbit corneas by splitting the stroma for a few millimeters, without closing sutures, remained in the cornea for two, four and six weeks respectively. In contrast to the stainless steel sutures an extensive tissue reaction could be obs

  12. The use of suture anchors to repair the ruptured quadriceps tendon.

    Science.gov (United States)

    Bushnell, Brandon D; Whitener, George B; Rubright, James H; Creighton, R Alexander; Logel, Kevin J; Wood, Mark L

    2007-07-01

    Quadriceps tendon rupture is an incapacitating injury that usually requires surgical repair. Traditional repair methods involve transpatellar suture tunnels, but recent reports have introduced the idea of using suture anchors to repair the ruptured tendon. We present 5 cases of our technique of using suture anchors to repair the ruptured quadriceps tendon.

  13. Development of a Constitutive Model of Polypropylene for Thermoforming

    Science.gov (United States)

    O'Connor, C.; Martin, P.; Menary, G.; Sweeney, J.; Caton-Rose, P.; Spencer, P.

    2011-05-01

    In this paper the authors outline a constitutive model, implemented within finite element analyses, which was developed for large deformation, high temperature multi-axial stretching of polypropylenes. The model has been generalised to a fully 3-dimensional thermally coupled form. The paper describes how model parameters were characterised using constant width, biaxial and sequential stretching of polypropylenes at elevated temperature using a custom built flexible biaxial stretching machine developed at Queen's University Belfast. The paper presents results of finite element model predictions of material stretching behaviour compared to range of physical experiments. The results presented in the paper confirm that this model is very effective in predicting the complex thermo-mechanical behaviours of polypropylenes at elevated temperatures.

  14. Use of radiation graft polymerization for modification of polypropylene

    Directory of Open Access Journals (Sweden)

    Saule Nauryzova

    2016-06-01

    Full Text Available The article investigates the process of applying the conductive layer on isotactic polypropylene modified by the radiation grafting monomer for improving the wettability of the surface. Presented IR spectra, the results of measuring the contact angle of the modified material indicate the improved surface hydrophilicity. The degree of grafting functional groups to the surface of isotactic polypropylene is determined. A scheme of gradual modification of polypropylene surface is presented. As the primary layer for the polymer metallization, copper-phosphorus film may be used. Copper-phosphorus films were obtained by reduction of copper compounds with phosphine gas. Experimental results show that the copper phosphide is electrically conductive coating and imparts an increased hardness.

  15. Polypropylene Fibers as Reinforcements of Polyester-Based Composites

    Directory of Open Access Journals (Sweden)

    Gonzalo Martínez-Barrera

    2013-01-01

    Full Text Available Effects of gamma radiation and the polypropylene fibers on compressive properties of polymer concrete composites (PC were studied. The PCs had a composition of 30 wt% of unsaturated polyester resin and 70 wt% of marble particles which have three different sizes (small, medium, and large. The PCs were submitted to 200, 250, and 300 kGy of radiation doses. The results show that the compressive properties depend on the combination of the polypropylene fiber concentration and the applied radiation dose. The compressive strength value is highest when using medium particle size, 0.1 vol% of polypropylene fibers and 250 kGy of dose; moreover, the compressive modulus decreases when increasing the particle size.

  16. Flexural Fatigue Behavior of Polypropylene Fiber Reinforeed Segment Conerete

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The influence of polypropylene fiber on the flexural fatigue performance of high- strength concrete (HSC), which could be used as cover of reinforcement of segment, was investigate by three-point load bending tests. Also, the flexural fatigue equations of high-strength concrete with and without polypropylene fiber were established through test analysis. The experimental results indicate that the addition of polypropylene fiber can improve the static bending strength of segment concrete, and the important is that it can markedly increase the flexural fatigue performance of the HSC subjected to cyclic bending load. Especially when with 1.37 kg/m3 addition of the fiber was corporate with silica fume and slag powder, the fatigue life of the HSC can be increased by 43.4% compared to that of the segment concrete without fiber,silica fume and slag.

  17. Cosmetic outcome and surgical site infection rates of antibacterial absorbable (Polyglactin 910) suture compared to Chinese silk suture in breast cancer surgery: a randomized pilot research

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhong-tao; Jessica Shen; Martin Weisberg; ZHANG Hong-wei; FANG Xue-dong; WANG Li-ming; LI Xiao-xi; LI Ya-fen; SUN Xiao-wei; Judith Carver; Dorella Simpkins

    2011-01-01

    Background The primary objective of this multicenter post-market study was to compare the cosmetic outcome of triclosan-coated VICRYL* Plus sutures with Chinese silk sutures for skin closure of modified radical mastectomy. A secondary objective was to assess the incidence of surgical site infection (SSI).Methods Patients undergoing modified radical mastectomy were randomly assigned to coated VICRYL* Plus antibacterial (Polyglactin 910) suture or Chinese silk suture. Cosmetic outcomes were evaluated postoperatively at days 12 (±2) and 30 (±5), and the evidence of SSI was assessed at days 3, 5, 7, 12 (±2), 30 (±5), and 90 (±7). Cosmetic outcomes were independently assessed via visual analogue scale (VAS) score evaluations of blinded incision photographs (primary endpoint) and surgeon-assessed modified Hollander Scale (mHCS) scores (secondary endpoint).SSI assessments used both CDC criteria and ASEPSIS scores.Results Six Chinese hospitals randomized 101 women undergoing modified radical mastectomy to closure with coated VICRYL* Plus suture (n=51) or Chinese silk suture (n=50). Mean VAS cosmetic outcome scores for antibacterial suture (67.2) were better than for Chinese silk (45.4) at day 30 (P<0.0001)). Mean mHCS cosmetic outcome total scores, were also higher for antibacterial suture (5.7) than for Chinese silk (5.0) at day 30 (P=0.002).Conclusions Patients using coated VICRYL* Plus suture had significantly better cosmetic outcomes than those with Chinese silk sutures. Patients using coated VICRYL* Plus suture had a lower SSI incidence compared to the Chinese silk sutures, although the difference did not reach statistical significance. (ClinicalTrials.gov NCT 00768222)

  18. Oxidation and degradation of polypropylene transvaginal mesh.

    Science.gov (United States)

    Talley, Anne D; Rogers, Bridget R; Iakovlev, Vladimir; Dunn, Russell F; Guelcher, Scott A

    2017-04-01

    Polypropylene (PP) transvaginal mesh (TVM) repair for stress urinary incontinence (SUI) has shown promising short-term objective cure rates. However, life-altering complications have been associated with the placement of PP mesh for SUI repair. PP degradation as a result of the foreign body reaction (FBR) has been proposed as a contributing factor to mesh complications. We hypothesized that PP oxidizes under in vitro conditions simulating the FBR, resulting in degradation of the PP. Three PP mid-urethral slings from two commercial manufacturers were evaluated. Test specimens (n = 6) were incubated in oxidative medium for up to 5 weeks. Oxidation was assessed by Fourier Transform Infrared Spectroscopy (FTIR), and degradation was evaluated by scanning electron microscopy (SEM). FTIR spectra of the slings revealed evidence of carbonyl and hydroxyl peaks after 5 weeks of incubation time, providing evidence of oxidation of PP. SEM images at 5 weeks showed evidence of surface degradation, including pitting and flaking. Thus, oxidation and degradation of PP pelvic mesh were evidenced by chemical and physical changes under simulated in vivo conditions. To assess changes in PP surface chemistry in vivo, fibers were recovered from PP mesh explanted from a single patient without formalin fixation, untreated (n = 5) or scraped (n = 5) to remove tissue, and analyzed by X-ray photoelectron spectroscopy. Mechanical scraping removed adherent tissue, revealing an underlying layer of oxidized PP. These findings underscore the need for further research into the relative contribution of oxidative degradation to complications associated with PP-based TVM devices in larger cohorts of patients.

  19. 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

  20. The 2.5 mm PushLock suture anchor system versus a traditional suture anchor for ulnar collateral ligament injuries of the thumb: a biomechanical study.

    Science.gov (United States)

    Jarrett, C D; McGillivary, G R; Hutton, W C

    2010-02-01

    We compared the biomechanical strength of the 2.5 mm PushLock suture anchor with a traditional Bio-SutureTak suture anchor in repair of ulnar collateral ligament injuries. Iatrogenic ulnar collateral ligament injuries in 18 cadaveric thumbs were repaired and used to test for load to failure and cyclic loading. The average force required to generate a 2 mm gap was 7.7 N for the 2.5 mm PushLock and 6.3 N for the Bio-SutureTak (p = 0.04). The ultimate load to failure was 28.0 N for the 2.5 mm PushLock and 18.8 N for the Bio-SutureTak (p = 0.16). There were no statistical differences between the two suture anchors under cyclic loading. The 2.5 mm PushLock suture anchor provides significantly stronger resistance to 2 mm gap formation at the repair site and is less likely to fail at the suture-ligament interface. However, there was no difference in the load to failure between the two suture anchors.

  1. Processing and characterization of redmud reinforced polypropylene composites

    Science.gov (United States)

    Shanmugavel, R.; Jayamani, M.; Nagarajan, R.; Irullappasamy, S.; Cardona, F.; Sultan, M. T. H.

    2016-10-01

    In this work, the redmud reinforced polypropylene composites were fabricated by compression molding setup. The effects of the redmud content on the mechanical, melting and crystalline behavior of the composites was investigated. The melting and crystalline behavior of the composites were investigated using Digital Scanning Calorimeter. The test results show that hardness of the composites increases with increasing redmud content while incorporation of redmud content decreases tensile and impact strength of the composites. It is determined that the addition of redmud on the polypropylene does not affect the crystalline behavior of the composites.

  2. Effect of Crystallinity on Electrical Conduction in Polypropylene

    Science.gov (United States)

    Ikezaki, Kazuo; Kaneko, Takanobu; Sakakibara, Toshio

    1981-03-01

    The electrical conduction of 20 μm thick polypropylene films with different crystallinities has been studied at 72°C below 400 kV/cm. The field dependence of the current shows that the conduction mechanism in this polymer is ion hopping. The estimated ionic jump distance strongly depends on the polymer crystallinity, and it decreases from 100 Å to 45 Å as the crystallinity increases from 50.5% to 78%. Preheating of samples seriously affects the electrical conduction in polypropylene, so differences in conductivity, activation energy and jump distance obtained by different authors can be explained partly by differences in the thermal history of the samples used.

  3. How we do it:the Running-X suture technique

    Institute of Scientific and Technical Information of China (English)

    Nathaniel L Villanueva; Kyle Sanniec; Ronald Mancini

    2016-01-01

    There are a myriad of suture techniques available to close incisions of the brow and forehead, each with their own advantages and disadvantages. The ideal suture technique would provide excellent cosmetic results, offer expedient wound closure, optimize skin eversion and wound edge apposition, and provide excellent cosmetic results. The authors describe a new suture technique, the Running-X suture, a running horizontal mattress suture that has successfully been used by the senior author for many years to re-approximate surgical wounds of the brow and forehead in an expeditious and aesthetic manner.

  4. Preparation and Characterization of Extruded Composites Based on Polypropylene and Chitosan Compatibilized with Polypropylene-Graft-Maleic Anhydride

    Directory of Open Access Journals (Sweden)

    Fernando Javier Carrasco-Guigón

    2017-01-01

    Full Text Available The preparation of composites of synthetic and natural polymers represent an interesting option to combine properties; in this manner, polypropylene and chitosan extruded films using a different proportion of components and polypropylene-graft-maleic anhydride (PPgMA as compatibilizer were prepared. The effect of the content of the biopolymer in the polypropylene (PP matrix, the addition of compatibilizer, and the particle size on the properties of the composites was analyzed using characterization by fourier transform-infrared spectroscopy (FT-IR, scanning electron microscopy (SEM, differential scanning calorimetry (DSC, tensile strength, and contact angle, finding that in general, the addition of the compatibilizer and reducing the particle size of the chitosan, favored the physicochemical and morphological properties of the films.

  5. Filament Winding of Co-Extruded Polypropylene Tapes for Fully Recyclable All-Polypropylene Composite Products

    Science.gov (United States)

    Cabrera, N. O.; Alcock, B.; Klompen, E. T. J.; Peijs, T.

    2008-01-01

    The creation of high-strength co-extruded polypropylene (PP) tapes allows the production of recyclable “all-polypropylene” (all-PP) composite products, with a large temperature processing window and a high fibre volume fraction. Available technologies for all-PP composites are mostly based on manufacturing processes such as thermoforming of pre-consolidated sheets. The objective of this research is to assess the potential of filament winding as a manufacturing process for all-PP composites made directly from co-extruded tapes or woven fabric. Filament wound pipes or rings were tested either by the split-disk method or a hydrostatic pressure test in order to determine the hoop properties, while an optical strain mapping system was used to measure the deformation of the pipe surfaces.

  6. ENHANCEMENT OF COMPATIBILITY OF POLYPROPYLENE AND NYLON-66 BY MALEATED POLYPROPYLENE

    Institute of Scientific and Technical Information of China (English)

    LI Xiaosan; WANG Dexi

    1992-01-01

    The compatibility of PP/N-66 blending system modified with maleated polypropylene was studied by means of SEM, DMA and other mechanical testing. It was found that when proper amount of modifier was applied, the compatibility was greatly enhanced and the impact toughness was significantly improved. An important direct evidence of the formation of the interfacial copolymer was also found. However, when excessive amount of modifier was used, the modification effect was not conspicuous. The phenomena were interpreted from a view of molecular motion that the interfacial block copolymer forced the two components to 'compatibilize' and many flexible PP molecules were set free from the restraint of the crystallites of plain PP so as to absorb much more impact energy.

  7. Assessment of the role of sutures in a lizard skull: a computer modelling study.

    Science.gov (United States)

    Moazen, Mehran; Curtis, Neil; O'Higgins, Paul; Jones, Marc E H; Evans, Susan E; Fagan, Michael J

    2009-01-01

    Sutures form an integral part of the functioning skull, but their role has long been debated among vertebrate morphologists and palaeontologists. Furthermore, the relationship between typical skull sutures, and those involved in cranial kinesis, is poorly understood. In a series of computational modelling studies, complex loading conditions obtained through multibody dynamics analysis were imposed on a finite element model of the skull of Uromastyx hardwickii, an akinetic herbivorous lizard. A finite element analysis (FEA) of a skull with no sutures revealed higher patterns of strain in regions where cranial sutures are located in the skull. From these findings, FEAs were performed on skulls with sutures (individual and groups of sutures) to investigate their role and function more thoroughly. Our results showed that individual sutures relieved strain locally, but only at the expense of elevated strain in other regions of the skull. These findings provide an insight into the behaviour of sutures and show how they are adapted to work together to distribute strain around the skull. Premature fusion of one suture could therefore lead to increased abnormal loading on other regions of the skull causing irregular bone growth and deformities. This detailed investigation also revealed that the frontal-parietal suture of the Uromastyx skull played a substantial role in relieving strain compared with the other sutures. This raises questions about the original role of mesokinesis in squamate evolution.

  8. Timing of ectocranial suture activity in Gorilla gorilla as related to cranial volume and dental eruption.

    Science.gov (United States)

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

    2011-05-01

    Research has shown that Pan and Homo have similar ectocranial suture synostosis patterns and a similar suture ontogeny (relative timing of suture fusion during the species ontogeny). This ontogeny includes patency during and after neurocranial expansion with a delayed bony response associated with adaptation to biomechanical forces generated by mastication. Here we investigate these relationships for Gorilla by examining the association among ectocranial suture morphology, cranial volume (as a proxy for neurocranial expansion) and dental development (as a proxy for the length of time that it has been masticating hard foods and exerting such strains on the cranial vault) in a large sample of Gorilla gorilla skulls. Two-hundred and fifty-five Gorilla gorilla skulls were examined for ectocranial suture closure status, cranial volume and dental eruption. Regression models were calculated for cranial volumes by suture activity, and Kendall's tau (a non-parametric measure of association) was calculated for dental eruption status by suture activity. Results suggest that, as reported for Pan and Homo, neurocranial expansion precedes suture synostosis activity. Here, Gorilla was shown to have a strong relationship between dental development and suture activity (synostosis). These data are suggestive of suture fusion extending further into ontogeny than brain expansion, similar to Homo and Pan. This finding allows for the possibility that masticatory forces influence ectocranial suture morphology.

  9. A STUDY ON METOPIC SUTURE IN CADAVERIC SKULLS OF ASSAMESE PEOPLE

    Directory of Open Access Journals (Sweden)

    Rubi

    2014-09-01

    Full Text Available Metopic suture is formed due to failure of union of the two halves of the frontal bone. Usually the suture disappears by early childhood, but in some cases it persists as complete or incomplete metopic suture throughout life. A complete metopic suture extends from anterior aspect of bregma to the nasion which is known as metopism. The present study is carried out in 126 dry human cadaveric skulls collected from the Dept. of Anatomy, Dept. of Forensic Medicine and Institute of Pharmacy at Assam Medical College & Hospital, Dibrugarh, Assam, and India. Metopic suture was found in 46(36.5% skulls. Metopism was found in 4(3.17% skulls and incomplete metopic suture was seen in 42(33.33% skulls. 80(63.49% skulls did not have metopic suture in any form.

  10. 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

  11. Modification of the Bankart reconstruction using a suture anchor.

    Science.gov (United States)

    Traina, S M; Holtgrewe, J L; King, S

    1998-01-01

    A prospective study was done to determine the effectiveness of a suture anchor in doing a Modified Bankart Reconstruction on the traumatic unidirectional Bankart lesion shoulder. From 1989 to 1991, 26 patients encompassing 27 shoulders with recurrent instability had modified Bankart reconstructions. A minimum 18-month follow-up was obtained by examination of 24 patients with telephone interviews done on two patients. The average follow-up was 23.6 months. A 93.1% good-to-excellent result was obtained using the Bankart rating scale. There were no failures or complications. The surgeon involved in the study thought the suture anchor facilitated the attachment of the avulsed capsulolabral complex in doing the Bankart procedure.

  12. Introduction to a Small 10/0.4 kV Substation User Operation Maintenance and Management%浅谈小型10/0.4kV用户变电所的运行维护管理

    Institute of Scientific and Technical Information of China (English)

    周瑞海

    2015-01-01

    Based on personal working experience, combined with the institute of 10/0.4 kV substation operation management, from the organization and management, prevention and maintenance, accident treatment and safe appliance and special improvement, etc are summarized, the simplified small customer substation management measures are put forward, at the same time, made clear the key to guarantee the safe operation of the substation must control management project and the corresponding requirements.%文章根据个人工作经历,结合研究所10/0.4kV变电所运行管理,从组织管理、预防及维护、事故处理及安全用具及特殊改进等方面进行了总结,提出了简化小型用户变电所的管理措施,同时明确了保证变电所安全运行必须控制的关键管理项目及相应要求。

  13. Transcutaneous Serdev Suture For Buttock’s Lift

    OpenAIRE

    Nikolay Serdev

    2012-01-01

    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 ...

  14. Microsurgical transverse 2-suture intussusception vasoepididymostomy: effectiveness and rationality

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hao; HUANG Wen-tao; RUAN Xing-xing; LI Liao-yuan; DI Jin-ming; LIU Xiao-peng; XIAO Heng-jun

    2013-01-01

    Background 2-Suture longitudinal vasoepididymostomy shows superiority to transverse technique in an animal study; to date,this has not been consistently confirmed in human body.In the present study,we evaluated the effectiveness of 2-suture transverse intussusception vasoepididymostomy and compared the rationality between transverse and longitudinal techniques.Methods From May 2007 to December 2008,we performed 2-suture transverse vasoepididymostomy in 19 consecutive patients,as described by Marmar with modification.Between March 2009 and January 2010,the internal diameter of the vas lumen and the outer diameter of the epididymal tube were measured using microruler (21 patients and 37 sides).Results Three patients lost to follow-up.At the first follow-up period (ranged from 10 to 24 months),the patency rate was 56.3% (9/16) and the natural pregnancy rate was 25% (4/16).At the second follow-up period (ranged from 46 to 63months),the patency rate was 68.8% (11/16),the natural pregnancy rate was 37.5% (6/16),respectively,and the takehome baby rate was 31.3% (5/16).The diameter of the vas lumen and the outer diameter of the epididymal tubule were (0.512±0.046) mm and (0.572±0.051) mm (P <0.001),respectively.Conclusion Transverse 2-suture intussusception vasoepididymostomy is still an effective technique in treating obstructive azoospermia.

  15. Dynamic Observation on the Effects of Different Suture Techniques on the Biomechanical Properties in the Healing of Tendons

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To identify the best suture techniques for the tendon repair, the biomechanical properties of tendons sutured by different methods were dynamically examined. 140 chickens were divided into 2 groups equally: group A and group B. The tendon of the right side was subjected to injury-repair process, and the tendons of the left sides served as controls in both groups. In group A, "figure-of8" suture, modified Kessler suture and Bunnell suture were used for the 2nd to 4th paws respectively, while in group B, Kleinert suture, Tsuge suture and Ikuta suture were used. On the day 0, 3,7, 14, 21, 28, 42 after operation, 10 animals were sacrificed and the flexor tendons of both sides were harvested for strength test. The results showed that the initial strength of the repaired tendons and the strength after 6 weeks following tendon cut were far below those of intact tendons, irrespective of suture techniques used. With the 6 techniques, the Pmax of tendons repaired by Tsuge suture was increased continually, reaching the highest value on the 42nd day. The Pmax of tendons sutured by the modified Kessler suture was slightly lower than that by Tsuge suture, but it was increased steadily in healing. The tendons repaired by figure-of-8 suture yielded the lowest Pmax. It was concluded that Tsuge suture and modified Kessler suture were the best techniques for tendon repair.

  16. The south Zagros suture zone in teleseismic images

    Science.gov (United States)

    Motaghi, K.; Shabanian, E.; Tatar, M.; Cuffaro, M.; Doglioni, C.

    2017-01-01

    The geometry of intra-continental lithosphere boundaries along the Zagros orogenic belt in the Arabia-Eurasia collision is investigated by means of teleseismic data. The data are gathered over a seismic linear profile extending across south Zagros, the Sanandaj-Sirjan metamorphic zone, the Urumieh-Dokhtar magmatic arc, Central Iran, and the Kopeh Dagh - Binalud mountains. We exploit the P and S receiver functions leading to map the geometry of the crustal and subcrustal interfaces. The migrated depth sections reveal an abrupt crustal thickening and a gentle crustal thinning 60 km north and 30 km south of the Zagros suture, respectively. Associated to the buckled antiformal Moho south of the suture, a deeper synform in the lithospheric lid of the lower Arabia plate is shown by migrated depth sections affecting the lithospheric mantle of the Arabia plate beneath the suture zone. This geometry implies an unexpected intra-lid decoupling. These features imply that the Central Iran lithosphere acts as a relatively strong backstop producing significant internal deformation expressed by shortening and thickening at the edge of the Arabian lithosphere. The 410 km and 660 km transition zones are imaged by P to S converted phases and showed lateral continuity implying an originally low dip angle subduction of the oceanic Arabian plate beneath Central Iran.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  18. Long chain branching on linear polypropylene by solid state reactions

    NARCIS (Netherlands)

    Borsig, E.; Gotsis, A. D.; Picchioni, F.

    2008-01-01

    A method was developed for the long chain branching (LCB) of isotactic polypropylene (iPP) via modification in the solid state. PP long chains have been linked as branches to the original linear iPP chains using solid state reactions in the presence of a free radical initiator and a multifunctional

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

    DEFF Research Database (Denmark)

    Calaon, Matteo; Tosello, Guido; Hansen, Hans Nørgaard

    2012-01-01

    having a diameter of 500 nm was employed. The tool insert surface was produced using chemical-based-batch techniques such aluminum anodization and nickel electroplating. During the injection molding process, polypropylene (PP) was employed as material and packing phase parameters (packing time, packing...... to the polymer part was mainly influenced by packing pressure level and distance from the gate....

  20. 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.

  1. Solution and Melt Rheology of Polypropylene Comb and Star Polymers

    Science.gov (United States)

    Ghosh, Arnav; Colby, Ralph H.; Rose, Jeffrey M.; Cherian, Anna E.; Coates, Geoffrey W.

    2006-03-01

    Syndiotactic polypropylene macromonomer arms have been prepared by coordination-insertion polymerization. These arms have been made into polypropylene star polymers by the homopolymerization of the syndiotactic arms with a living alkene polymerization catalyst. The macromonomer arms have also been randomly copolymerized with propylene using rac-dimethylsilyl(2-methyl-4-phenylindenyl) zirconium dichloride catalysts to make polypropylene combs. Consequently we have star polymers and a series of comb polymers with different backbone lengths that are all made from the same macromonomer arms. We compare linear viscoelastic data on star and comb polypropylene melts and solutions in squalane to predictions of the tube dilation model and the tube model without tube dilation. The ratio of comb terminal relaxation time to star terminal relaxation time eliminates the friction coefficient and allows determination of the extent of tube dilation the backbone experiences when it relaxes. The concentration dependence of the comb/star terminal relaxation time ratio can be described by either model, owing to adjustable parameters that are not known apriori, so independent means to evaluate those parameters will be discussed.

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

    Institute of Scientific and Technical Information of China (English)

    Guangyao Liu; Qiao Zhang; Yan Jin; Zhongli Gao

    2012-01-01

    The magnitude of tensile stress and tensile strain at an anastomosis site under physiological stress is an important factor for the success of anastomosis following suturing in peripheral nerve injury treatment.Sciatic nerves from fresh adult cadavers were used to create models of sciatic nerve injury.The denervated specimens underwent epineurial and perineurial suturing.The elastic modulus (40.96 ± 2.59 MPa) and Poisson ratio (0.37 ± 0.02) of the normal sciatic nerve were measured by strain electrical measurement.A resistance strain gauge was pasted on the front,back,left,and right of the edge of the anastomosis site after suturing.Strain electrical measurement results showed that the stress and strain values of the sciatic nerve following perineurial suturing were lower than those following epineurial suturing.Scanning electron microscopy revealed that the sciatic nerve fibers were disordered following epineurial compared with perineurial suturing.These results indicate that the effect of perineurial suturing in sciatic nerve injury repair is better than that of epineurial suturing.

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

    Directory of Open Access Journals (Sweden)

    Santiago Estupiñán-Díaz

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mirković Siniša

    2011-01-01

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

  5. Bundles of spider silk, braided into sutures, resist basic cyclic tests: potential use for flexor tendon repair.

    Directory of Open Access Journals (Sweden)

    Kathleen Hennecke

    Full Text Available Repair success for injuries to the flexor tendon in the hand is often limited by the in vivo behaviour of the suture used for repair. Common problems associated with the choice of suture material include increased risk of infection, foreign body reactions, and inappropriate mechanical responses, particularly decreases in mechanical properties over time. Improved suture materials are therefore needed. As high-performance materials with excellent tensile strength, spider silk fibres are an extremely promising candidate for use in surgical sutures. However, the mechanical behaviour of sutures comprised of individual silk fibres braided together has not been thoroughly investigated. In the present study, we characterise the maximum tensile strength, stress, strain, elastic modulus, and fatigue response of silk sutures produced using different braiding methods to investigate the influence of braiding on the tensile properties of the sutures. The mechanical properties of conventional surgical sutures are also characterised to assess whether silk offers any advantages over conventional suture materials. The results demonstrate that braiding single spider silk fibres together produces strong sutures with excellent fatigue behaviour; the braided silk sutures exhibited tensile strengths comparable to those of conventional sutures and no loss of strength over 1000 fatigue cycles. In addition, the braiding technique had a significant influence on the tensile properties of the braided silk sutures. These results suggest that braided spider silk could be suitable for use as sutures in flexor tendon repair, providing similar tensile behaviour and improved fatigue properties compared with conventional suture materials.

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    2010-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Chien-Lin Huang

    2015-11-01

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

  9. A new, removable, sliding noose for adjustable-suture strabismus surgery.

    Science.gov (United States)

    Deschler, Emily K; Irsch, Kristina; Guyton, Kristina L; Guyton, David L

    2013-10-01

    We describe a new removable sliding polyglactin 910 suture noose for postoperative suture adjustment following extraocular muscle surgery. No excess suture material remains after adjustment has been completed, helping to reduce discomfort, inflammation, and scarring. We have used this noose with the cul-de-sac conjunctival incision in approximately 360 patients over a period of 18 months. This report details how to fashion, use, and remove the noose.

  10. Photometric analysis of absorbable barbed suture for periareolar closure in mastopexy

    Institute of Scientific and Technical Information of China (English)

    Allen D Rosen; Alanna M Guzman; Teresa Hartman

    2016-01-01

    Aim:The primary author previously described his technique for periareolar closure in mastopexy using a pinwheel interlocking purse string with absorbable barbed suture and now reports the results of a retrospective photometric analysis comparing this technique with the same closure using Gortex® suture. This study is designed to compare the degree of areolar widening and safety proifle of using absorbable barbed sutures for periareolar closure versus permanent smooth suture. Methods:A retrospective chart review was conducted of all patients whose periareolar closures were performed using an interlocking purse-string technique over a 10-year period. Only patients undergoing circumvertical mastopexy were included. All had photometric evaluation and follow-up performed within 6-24 months. Results:In total, 20 patients (40 areolas), which were closed with absorbable barbed suture, were analyzed photometrically. In this suture group, areola size increased a mean of 4.9%from baseline, and no complications (0%) were observed. This compared favorably with previously reported complication rates using permanent sutures and with a series of cases presented herein in which permanent smooth suture was used for purse string closure. The degree to which absorbable barbed suture controls areolar spread was shown to be signiifcantly better than those where permanent smooth purse string techniques were employed. Conclusion:Circumvertical mastopexy closures using absorbable barbed suture was shown to be safe and effective and compared favorably to older techniques using permanent smooth suture for similar closures. This paper lends support to the safety of using absorbable barbed suture in circumareolar closures to limit areolar spread.

  11. Clinical Outcomes After Suture Anchor Repair of Recalcitrant Medial Epicondylitis.

    Science.gov (United States)

    Grawe, Brian M; Fabricant, Peter D; Chin, Christopher S; Allen, Answorth A; DePalma, Brian J; Dines, David M; Altchek, David W; Dines, Joshua S

    2016-01-01

    This study evaluated clinical and patient-reported outcomes and return to sport after surgical treatment of medial epicondylitis with suture anchor fixation. Consecutive patients were evaluated after undergoing debridement and suture anchor repair of the flexor-pronator mass for the treatment of medial epicondylitis. Demographic variables, a short version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, Oxford Elbow Score (OES), and 10-point pain and satisfaction scales were collected. Ability and time to return to sport after surgery were evaluated, and the relationship between predictor variables and both elbow function and return to sport was investigated. Median age at the time of surgery was 55 years (range, 29-65 years), with median follow-up of 40 months (range, 12-67 months). Median QuickDASH score and OES at final follow-up were 2.3 (range, 0-38.6) and 45 (range, 22-48), respectively. Most patients returned to premorbid sporting activities at a median of 4.5 months (range, 2.5-12 months), whereas 4 patients (14%) reported significant limitations at final follow-up. Older age at the time of surgery was predictive of better QuickDASH score and OES (P=.05 and P=.02, respectively). Patients who underwent surgery after a shorter duration of symptoms had better outcomes, but the difference did not reach statistical significance (QuickDASH, P=.09; OES, P=.10). Surgical treatment of recalcitrant medial epicondylitis with suture anchor fixation offers good pain relief and patient satisfaction, with little residual disability. Older age at the time of surgery predicts a better outcome.

  12. Radiographic and microscopic anatomy of the mid-palatal suture in the elderly.

    Science.gov (United States)

    N'Guyen, T; Ayral, X; Vacher, C

    2008-02-01

    In a previous radiological study of the mid-palatal suture, it has been demonstrated that its obliteration was occurring during adult life and varied. In order to determine the histological status of mid-palatal suture in elderly men, 20 human palates aged more than 70 were examined by occlusal radiographs and histological study of the suture. In all palates the suture was ossified in the anterior thirds and made of conjunctive tissue in the posterior third. This particular evolution could be correlated to the mastication forces acting on the maxillary bones during the entire life.

  13. Effect of residents' previous laparoscopic surgery experience on initial robotic suturing experience.

    Science.gov (United States)

    Kilic, Gokhan Sami; Walsh, Teresa M; Borahay, Mostafa; Zeybek, Burak; Wen, Michael; Breitkopf, Daniel

    2012-01-01

    Objective. To assess the impact of gynecology residents' previous laparoscopic experience on the learning curve of robotic suturing techniques and the value of initial structured teaching in dry lab prior to surgery. Methods. Thirteen gynecology residents with no previous robotic surgery experience were divided into Group 1, consisting of residents with 2 or fewer laparoscopic experiences, and Group 2, consisting of residents with 3 or more laparoscopic experiences. Group 1 had a dry-laboratory training in suturing prior to their initial experience in the operating room. Results. For all residents, it took on average 382 ± 159 seconds for laparoscopic suturing and 326 ± 196 seconds for robotic suturing (P = 0.12). Residents in Group 1 had a lower mean suture time than residents in Group 2 for laparoscopic suturing (P = 0.009). The residents in Group 2, however, had a lower mean suture time on the robot compared to Group 1 (P = 0.5). Conclusion. Residents with previous laparoscopic suturing experience may gain more from a robotic surgery experience than those with limited laparoscopic surgery experience. In addition, dry lab training is more efficient than hands-on training in the initial phase of teaching for both laparoscopic and robotic suturing skills.

  14. Surgical sutures filled with adipose-derived stem cells promote wound healing.

    Directory of Open Access Journals (Sweden)

    Ann Katharin Reckhenrich

    Full Text Available Delayed wound healing and scar formation are among the most frequent complications after surgical interventions. Although biodegradable surgical sutures present an excellent drug delivery opportunity, their primary function is tissue fixation. Mesenchymal stem cells (MSC act as trophic mediators and are successful in activating biomaterials. Here biodegradable sutures were filled with adipose-derived mesenchymal stem cells (ASC to provide a pro-regenerative environment at the injured site. Results showed that after filling, ASCs attach to the suture material, distribute equally throughout the filaments, and remain viable in the suture. Among a broad panel of cytokines, cell-filled sutures constantly release vascular endothelial growth factor to supernatants. Such conditioned media was evaluated in an in vitro wound healing assay and showed a significant decrease in the open wound area compared to controls. After suturing in an ex vivo wound model, cells remained in the suture and maintained their metabolic activity. Furthermore, cell-filled sutures can be cryopreserved without losing their viability. This study presents an innovative approach to equip surgical sutures with pro-regenerative features and allows the treatment and fixation of wounds in one step, therefore representing a promising tool to promote wound healing after injury.

  15. 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.

  16. 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.

  17. Suture anchor repair of quadriceps tendon rupture after total knee arthroplasty.

    Science.gov (United States)

    Kim, Tae Won B; Kamath, Atul F; Israelite, Craig L

    2011-08-01

    Disruption of the extensor mechanism after total knee arthroplasty (TKA) is a devastating complication, usually requiring surgical repair. Although suture anchor fixation is well described for repair of the ruptured native knee quadriceps tendon, no study has discussed the use of suture anchors in quadriceps repair after TKA. We present an illustrative case of successful suture anchor fixation of the quadriceps mechanism after TKA. The procedure has been performed in a total of 3 patients. A surgical technique and brief review of the literature follows. Suture anchor fixation of the quadriceps tendon is a viable option in the setting of rupture after TKA.

  18. Biomechanical study on the suture strength of ligament in cruciate ligament reconstruction

    Institute of Scientific and Technical Information of China (English)

    张春礼; 李起鸿; 杨柳

    2003-01-01

    Objective: To test the suture strength on the tendon or ligament end and evaluate the stitch in the reconstruction of cruciate ligament and its clinical application. Methods: Twenty-four specimens of patellar tendon with free ends were divided into 3 groups: Group I (3 Krackow stitches), Group II (2 Krackow stitches) and Group III (2 Krackow stitches with the first stitch passing through the tendon tissue as a modified Krackow stitch). These 3 groups were further divided into 6 subgroups according to different suture materials, No 1 Ethilon or stainless steel wire (φ= 0.4 mm). Tensile test was undertaken to find out the least stitches with efficient suture pattern. Results: Two Krackow locking stitches had stronger strength than 0.4 mm-diameter stainless steel wire. The fixation strength of 2 stitches with No 1 Ethilon was more than 80 N, superior to the failure strength of the material itself. The same strength was maintained if the first stitch was across the tendon tissue transversely. There was no statistically significant difference in the suture strength between 2 and 3 Krackow locking stitches. Conclusions: The suture strength is greater than the failure strength of the suture material. Less suture exposure can be achieved when the first stitch is across the tendon tissue while maintaining a comparable strength to other sutures. To attain higher suture strength, stronger materials or multiple strands rather than more stitches are preferred. Therefore, a rapid early rehabilitation of range of motion (ROM) is possible and reliable in practice.

  19. Effects of suture position on left ventricular fluid mechanics under mitral valve edge-to-edge repair.

    Science.gov (United States)

    Du, Dongxing; Jiang, Song; Wang, Ze; Hu, Yingying; He, Zhaoming

    2014-01-01

    Mitral valve (MV) edge-to-edge repair (ETER) is a surgical procedure for the correction of mitral valve regurgitation by suturing the free edge of the leaflets. The leaflets are often sutured at three different positions: central, lateral and commissural portions. To study the effects of position of suture on left ventricular (LV) fluid mechanics under mitral valve ETER, a parametric model of MV-LV system during diastole was developed. The distribution and development of vortex and atrio-ventricular pressure under different suture position were investigated. Results show that the MV sutured at central and lateral in ETER creates two vortex rings around two jets, compared with single vortex ring around one jet of the MV sutured at commissure. Smaller total orifices lead to a higher pressure difference across the atrio-ventricular leaflets in diastole. The central suture generates smaller wall shear stresses than the lateral suture, while the commissural suture generated the minimum wall shear stresses in ETER.

  20. Development of a sensor for polypropylene degradation products.

    Energy Technology Data Exchange (ETDEWEB)

    Sawyer, Patricia Sue; Howell, Stephen Wayne; Hochrein, James Michael; Dirk, Shawn M.; Bernstein, Robert; Washburn, Cody M.; Graf, Darin C.

    2009-04-01

    This paper presents the development of a sensor to detect the oxidative and radiation induced degradation of polypropylene. Recently we have examined the use of crosslinked assemblies of nanoparticles as a chemiresistor-type sensor for the degradation products. We have developed a simple method that uses a siloxane matrix to fabricate a chemiresistor-type sensor that minimizes the swelling transduction mechanism while optimizing the change in dielectric response. These sensors were exposed with the use of a gas chromatography system to three previously identified polypropylene degradation products including 4-methyl-2-pentanone, acetone, and 2-pentanone. The limits of detection 210 ppb for 4-methy-2-pentanone, 575 ppb for 2-pentanone, and the LoD was unable to be determined for acetone due to incomplete separation from the carbon disulfide carrier.

  1. Properties of Recycled Aggregate Concrete Reinforced with Polypropylene Fibre

    Directory of Open Access Journals (Sweden)

    Wan Mohammad Wan Nur Syazwani

    2016-01-01

    Full Text Available This research work is aimed to investigate how the addition of various proportion of polypropylene fibre affects the mechanical strength and permeability characteristics of recycled aggregate concrete (RAC which has been produced with treated coarse recycled concrete aggregate (RCA. Further research on RAC properties and their applications is of great importance as the scarcity of virgin aggregate sources in close proximity to major urban centers is becoming a worldwide problem. In this study, the hardened RAC properties at the curing age of 7 and 28 days such as compressive strength, flexural strength, ultrasonic pulse velocity (UPV, water absorption and total porosity were evaluated and compare with control specimens. Experimental result indicates that although the inclusion of the treated coarse RCA can enhance the mechanical strength and permeability properties of RAC, Further modification by addition of polypropylene fibre can optimize the results.

  2. Mechanical properties of pineapple leaf fibre reinforced polypropylene composites

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

  3. 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.

  4. Reinforced polypropylene composites: effects of chemical compositions and particle size.

    Science.gov (United States)

    Ashori, Alireza; Nourbakhsh, Amir

    2010-04-01

    In this work, the effects of wood species, particle sizes and hot-water treatment on some physical and mechanical properties of wood-plastic composites were studied. Composites of thermoplastic reinforced with oak (Quercus castaneifolia) and pine (Pinus eldarica) wood were prepared. Polypropylene (PP) and maleic anhydride grafted polypropylene (MAPP) were used as the polymer matrix and coupling agent, respectively. The results showed that pine fiber had significant effect on the mechanical properties considered in this study. This effect is explained by the higher fiber length and aspect ratio of pine compared to the oak fiber. The hot-water treated (extractive-free) samples, in both wood species, improved the tensile, flexural and impact properties, but increased the water absorption for 24h. This work clearly showed that lignocellulosic materials in both forms of fiber and flour could be effectively used as reinforcing elements in PP matrix. Furthermore, extractives have marked effects on the mechanical and physical properties.

  5. Avoiding adsorption of DNA to polypropylene tubes and denaturation of short DNA fragments

    OpenAIRE

    Gaillard, Claire; Strauss, Francois

    1998-01-01

    Two problems can arise when working with small quantities of DNA in polypropylene tubes: first, significant amounts of DNA can become lost by sticking to the tube walls; second, short DNA fragments tend to denature when binding to polypropylene. In addition, DNA also tends to denature upon dehydration. We have found that a simple way to solve these problems is by using polyallomer tubes instead of polypropylene and by avoiding certain salts, such as sodium acetate, when drying DNA.

  6. Newly Designed Polypropylene Polyol with Terminated Primary Hydroxy Group and Application for Polyurethane Foam

    Institute of Scientific and Technical Information of China (English)

    K.Maeda; M.Kaku; Y.Sakural; K.Nishiyama; H.Nakaminami

    2007-01-01

    1 Results Polypropylene polyol is very important chemical materials for polyurethane. We developed newly designed polypropylene polyol with terminated primary hydroxyl group. We focus on our new polypropylene polyol, and show its useful application for polyurethane foam. Polymerization of propyleneoxide is conventionally carried out in anionic polymerization process. In anionic process α-cleavage of propyleneoxide occurs rather than β-cleavage. Then the terminal hydroxyl group of the resulting polypropy...

  7. Investigation of New Isotactic Polypropylene and Syndiotactic Polystyrene Materials for High Pulsed Power Capacitors

    Science.gov (United States)

    2008-08-08

    polypropylene (LCBPP) and PVDF copolymers, toward the Navy capacitor goal with energy density >30 J/cc and low energy loss. The approach in LCBPPs is to...SUBJECT TERMS high energy density capacitor , high pulsed power capacitor , polypropylene , LCBPP, PVDF. 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF 18...08/08/2008 Final Report 01/01/2005 - 02/28/2008 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Investigation of new Isotactic Polypropylene and Syndiotactic

  8. Elastic and electromechanical properties of polypropylene foam ferroelectrets

    Science.gov (United States)

    Dansachmüller, M.; Schwödiauer, R.; Bauer-Gogonea, S.; Bauer, S.; Paajanen, M.; Raukola, J.

    2005-01-01

    Internally charged closed-cell polymer electrets exhibit ferroelectric-like behavior and have been called ferroelectrets. They are attractive for soft electroactive transducers, the high compressibility leads to d33 transducer coefficients exceeding those of ferroelectric polymers. A technique for the measurement of the elastic modulus and the transducer coefficient of ferroelectrets is reported. The elastic behavior of ferroelectretic polypropylene foams is correlated with the piezoelectric-like properties. Prestress treatments linearize the transducer properties.

  9. Properties of isotactic polypropylene irradiated in various atmospheres

    OpenAIRE

    Miličević Dejan S.; Suljovrujić Edin H.

    2010-01-01

    In this paper, changes in structure and physical properties of stabilized isotactic polypropylene (iPP) were created by gamma irradiation, up to a dose of 700 kGy, in different media: air, deionized distilled (DD) water and acetylene. Two main effects occur when polyolefins, such as iPP, are subjected to ionizing radiation: crosslinking and scission of macromolecules. The domination of one or the other of these competitive processes is determined by both the structural peculiarities of the po...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-01

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

  11. Evaluation of foaming polypropylene modified with ramified polymer

    OpenAIRE

    Demori,Renan; Azeredo,Ana Paula de; Liberman, Susana Alcira; Mauler,Raquel Santos

    2015-01-01

    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 c...

  12. Heat Transfer of Mineral-Filled Polypropylene Foams

    OpenAIRE

    Antunes, Marcelo de Sousa Pais; Redondo Realinho, Vera Cristina de; Martínez Benasat, Antonio; Solórzano Quijano, Eusebio; Rodríguez-Pérez, Miguel Ángel; Velasco Perero, José Ignacio

    2010-01-01

    The thermal conductivity of unfilled polypropylene foams produced using different foaming processes has previously been demonstrated to be mainly affected by the foam’s bulk density [1]. The influence of adding inorganic particles is now studied, with the thermal conductivity of the mineral-filled PP foams being determined using the Transient Plane Source Method (TPS). To this end, two different fillers were used. The incorporation of high amounts (50 and 70 wt.%) of magnesium ...

  13. Modification of isotactic polypropylene with styrene block-copolymers

    OpenAIRE

    DENAC, Matjaž; Musil, Vojko; Makarovič, Matjaž

    2015-01-01

    With a modification the current properties of polymeric material can be improved, and even some new properties can be obtained. The success of polymeric modifiers mostly depend on the interaction intensity at the phase boundary of the polymer/modifier. The influence of polymeric modifiers on polypropylene matrices were investigated. Different sorts and types of styrene block-copolymers were used in a concentration range up to 20 vol.%. Samples were prepared by melt-mixing in a Brabender knead...

  14. 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.

  15. Crystallization kinetics of polypropylenes. Effect of nucleating agents?

    OpenAIRE

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

    2008-01-01

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

  16. 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.

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

    Directory of Open Access Journals (Sweden)

    A. Kmetty

    2013-02-01

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

  18. Rheological study of polypropylene irradiated with polyfunctional monomers

    Science.gov (United States)

    Otaguro, H.; Rogero, S. O.; Yoshiga, A.; Lima, L. F. C. P.; Parra, D. F.; Artel, B. W. H.; Lugão, A. B.

    2007-12-01

    The aim of this paper is to investigate the rheological properties of polypropylene (PP) modified by ionization radiation (gamma rays) in the presence of two different monomers. The samples were mixed in a twin-screw extruder with ethylene glycol dimethacrylate (EGDMA) or trimethylolpropane trimethacrylate (TMPTMA) with concentration in the range of 0.5-5.0 mmol. After that, they were irradiated with 20 kGy dose of gamma radiation. The structural modification of polypropylene was analyzed in the melt state by measuring melt flow rate (MFR), η* (complex viscosity) and G' (storage modulus) in the angular frequency range of 10 -1 to 3 × 10 2 rad s -1. From the oscillatory rheology data, one could obtain the values of η0 (zero shear viscosity) that would be related to the molar mass. All results were discussed with respect to the crosslinking and degradation process that occur in the post-reactor treatment to produce controlled rheology polypropylene. The resulting polymeric materials were submitted the cytotoxicity in vitro test by neutral red uptake methodology with NCTC L 929 cell line from American Type Culture Collection bank. All modified PP samples presented no cytotoxicity.

  19. 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.

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

    Science.gov (United States)

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

    2014-09-01

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

  1. Choice of surgical suture material used in oral cavity: Clinical study

    Directory of Open Access Journals (Sweden)

    Mirković Siniša

    2010-01-01

    Full Text Available Introduction. 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. type and diameter, depends on the localization, characteristics and condition of the tissue to be treated. From the stand-point of oral-surgical practice the following clinical parameters are of the outstanding importance regarding the choice of suture material: accumulation of soft deposits on the sutures, decubitus of the adjacent soft tissues and dehiscence of the operative wound. Aim. The aim of this research was to determine the correlation between different types of suture materials and accumulation of soft deposits on the sutures, decubitus of the adjacent soft tissues and dehiscence of the operative wound. Material and methods. Our prospective clinical study included 150 patients distributed into three groups of 50 subjects. The surgical procedure performed on each patient involved resection (apicoectomy of the tooth root end in the intercanine sector of the upper jaw. The following suture materials were applied: BLACK SILK 5-0, NYLON 5-0 and VICRYL 5-0. The effects of the selected sutures were evaluated by using several parameters: accumulation of soft deposits, wound dehiscence and decubitus of the adjacent soft tissues. The effects of the applied sutures were recorded on days 2, 5 and 7 after the surgery. Conclusion. The comparison of cited parameters of the investigated materials after suture of oral cavity mucosa revealed that none of the used material was ideal; however, a certain preference might be given to the synthetic monofilament suture materials.

  2. Stabilization of polypropylene, polypropylene blends with poly (styrene-b-(ethylene-co-butylene)-b-styrene) under irradiation: A comparative investigation

    Energy Technology Data Exchange (ETDEWEB)

    Luan Shifang; Yang Huawei; Shi Hengchong; Zhao Jie [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Wang Jianwei [Shandong Weigao Group Medical Polymer Company Limited, Weihai 264209 (China); Yin Jinghua, E-mail: yinjh@ciac.jl.c [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2011-01-15

    The aim of this paper is to investigate the stabilization of polypropylene in the poly (styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS)/polypropylene (PP) blends under irradiation with respect to PP. The PP films, SEBS/PP films were subjected to electron beam irradiation and characterized by wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), gel permeation chromatography (GPC), and dynamic mechanical thermal analysis (DMTA). It demonstrated that upon irradiation, the molecular weight of PP had a pronounced decrease due to the major chain scission, and the minor chain cross-linking or chain branching occurred at the higher irradiation dose. Stabilization of PP was improved in the presence of SEBS, exhibiting an enhanced irradiation resistance.

  3. 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

  4. SYNTHESIS OF STYRYL-CAPPED POLYPROPYLENE via METALLOCENE-MEDIATED COORDINATION POLYMERIZATION: APPLY TO POLYPROPYLENE MACROMOLECULAR ENGINEERING

    Institute of Scientific and Technical Information of China (English)

    Hua-hua Huang; Chuan-hui Zhang; Ya-wei Qin; Hui Niu; Jin-yong Dong

    2013-01-01

    In this paper,we review our recent progress in the synthesis and application of styryl-capped polypropylene (PP-tSt),an excellent reactive polyolefin that is both convenient and efficient in synthesis and facile and versatile in application for preparing advanced polypropylene materials via macromolecular engineering.The synthesis of PP-t-St is made possible by a unique chain transfer reaction coordinated by a bis-styrenic molecule,such as 1,4-divinylbenzene (DVB) and 1,2-bis(4-vinylphenyl)ethane (BVPE),and hydrogen in typical C2-symmetric metallocene (e.g.rac-Me2Si(2-Me-4-Ph-Ind)2ZrC12,in association with methylaluminocene,MAO) catalyzed propylene polymerization.The regio-selective 2,1-insertion of the styrenic double bond in DVB or BVPE into the overwhelmingly 1,2-fashioned Zr-PP propagating chain enables substantial dormancy of the catalyst active site,which triggers selective hydrogen chain transfer that,with the formed Zr-H species ultimately saturated by the insertion of propylene monomer,results in an exclusive capping of the afforded PP chains by styryl group at the termination end.With a highly reactive styryl group at chain end,PP-t-St has been used as a facile building block in PP macromolecular engineering together with the employment of state-of-the-art synthetic polymer chemistry to fabricate broad types of new polypropylene architectures.

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

    KAUST Repository

    Yudhanto, Arief

    2016-03-08

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

  6. Development of novel melt-compounded starch-grafted polypropylene/polypropylene-grafted maleic anhydride/organoclay ternary hybrids

    Directory of Open Access Journals (Sweden)

    E. Lafranche

    2012-11-01

    Full Text Available Starch-grafted polypropylene (PP-g-starch/organoclay nanocomposites were melt-compounded using a corotating twin-screw extruder. Homopolymer or copolymer-based polypropylene-grafted maleic anhydrides (PP-g-MA with different molecular weights and different maleic anhydride (MA grafting levels were added at different weight contents as compatibilizer. Two organo-modified montmorillonites were used, the first one containing polar functional groups (Cloisite®30B having affinity to the starch phase, and the other one containing non polar-groups (Cloisite®20A having affinity to the polypropylene phase of the polymer matrix. Whatever the MA grafting level and the molecular weight and content of PP-g-MA, no significant immiscibility of PP-g-starch/PP-g-MA blends is evidenced. Regarding clay dispersion, adding a low content of ethylene-propylene copolymer-based PP-g-MA compatibilizer having a high MA-grafting level, and a polar organoclay (Cloisite®30B is the most desirable formulation to optimize clay intercalation and exfoliation in PP-g-starch. Nevertheless, regarding the reinforcement effect, whatever the PP-g-MA compatibilizer, the addition of non polar organoclay (Cloisite®20A is preferably recommended to reach higher tensile properties (modulus, yield stress, strength without significant loss of ductility.

  7. Antibacterial-Coated Suture in Reducing Surgical Site Infection in Breast Surgery: A Prospective Study

    Directory of Open Access Journals (Sweden)

    Enora Laas

    2012-01-01

    Full Text Available Background. To reduce the incidence of microbial colonization of suture material, Triclosan- (TC-coated suture materials have been developed. The aim of this study was to assess the incidence of suture-related complications (SRC in breast surgery with and without the use of TC-coated sutures. Methods. We performed a study on two consecutive periods: 92 patients underwent breast surgery with conventional sutures (Group 1 and 98 with TC-coated sutures (Group 2. We performed subgroups analyses and developed a model to predict SRC in Group 1 and tested its clinical efficacy in Group 2 using a nomogram-based approach. Results. The SRC rates were 13% in Group 1 and 8% in Group 2. We found that some subgroups may benefit from TC-coated sutures. The discrimination obtained from a logistic regression model developed in Group 1 and based on multifocality, age and axillary lymphadenectomy was 0.88 (95% CI 0.77–0.95 (. There was a significant difference in Group 2 between predicted probabilities and observed percentages (. The predicted and observed proportions of complications in the high-risk group were 38% and 13%, respectively. Conclusion. This study used individual predictions of SRC and showed that using TC-coated suture may prevent SRC. This was particularly significant in high-risk patients.

  8. Age changes in the human frontozygomatic suture from 20 to 95 years.

    Science.gov (United States)

    Kokich, V G

    1976-04-01

    The frontozygomatic suture of human cadaver material was examined by a combination of histologic, radiographic, and gross tecniques to determine the aging changes in the suture and the approximate age at which sutural fusion occurs. The sample consisted of sixty-One specimens of human beings ranging in age from 20 to 95 years. Observations were made on specimens at age intervals of 5 years. Since the frontozygomatic suture is bilateral, one suture from each specimens was used for radiographic and gross examination for synostosis, and the opposite side was subjected to histologic analysis. The findings of this study have lead to the following conclusions: 1. The human frontozygomatic suture undergoes synostosis during the eigth decade of life, but does not completely fuse by the age of 95 years. 2. Synostosis is a progressive process which commences as small areas of bony union that occur initially within the internal portion of the suture and then progresses to the orbital perisosteal surface. Bony union is not found at or near the facial periosteal surface. 3. The bony surfaces of the frontozygomatic suture become increasingly irregular with advancing age as a result of the formation of projections or interifitations=

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

    DEFF Research Database (Denmark)

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

    1988-01-01

    A controlled trial was set up to compare the treatment of wound abscesses, occurring after laparotomy, with either early secondary suture combined with cefuroxime and metronidazole given intravenously or by healing by second intention. The secondary suture was performed two days after wound...... drainage and resulted in a significant reduction (p less than 0.01) in healing time without complications. No reinfections occurred....

  10. Prospective randomized controlled trial investigating the type of sutures used during hepatectomy

    Institute of Scientific and Technical Information of China (English)

    Norifumi Harimoto; Ken Shirabe; Tomoyuki Abe; Takafumi Yukaya; Eiji Tsujita; Tomonobu Gion; Kiyoshi Kajiyama; Takashi Nagaie

    2011-01-01

    AIM: To determine whether absorbable sutures or non-absorbable sutures are better in preventing surgical site infection (SSI), in this paper we discuss the results of a randomized clinical trial which examined the type of sutures used during hepatectomy. METHODS: All hepatic resections performed from January 2007 to November 2008 at the Department of Surgery at Iizuka Hospital in Japan were included in this study. There were 125 patients randomly assigned to an absorbable sutures (Vicryl) group or non-absorbable sutures (Silk) group. RESULTS: SSI was observed in 13.6% (17/125) patients participating in this study, 11.3% in the Vicryl group and 15.8% in the Silk group. Incisional SSI including superficial and deep SSI, was observed in 8% of the Vicryl group and 9.5% of the Silk group. Organ/ space SSI was observed in 3.2% of the Vicryl group and 6.0% of the Silk group. There were no significant differences, but among the patients with SSI, the period for recovery was significantly shorter for the Vicryl group compared to the Silk group. CONCLUSION: The incidence of SSI in patients receiving absorbable sutures and silk sutures is not significantly different in this randomized controlled study; however, the period for recovery in patients with SSI was significantly shorter for absorbable sutures.

  11. Laparoscopic suturing learning curve in an open versus closed box trainer

    NARCIS (Netherlands)

    Rodrigues, S.P.; Horeman, T.; Blomjous, M.S.H.; Hiemstra, E.; Van den Dobbelsteen, J.J.; Jansen, F.W.

    2015-01-01

    Background The aim of this study was to examine the influence of training under direct vision prior to training with indirect vision on the learning curve of the laparoscopic suture task. Methods Novices were randomized in two groups. Group 1 performed three suturing tasks in a transparent laparosc

  12. Interactive Virtual Suturing Simulations: Enhancement of Student Learning in Veterinary Medicine

    Science.gov (United States)

    Staton, Amy J.; Boyd, Christine B.

    2013-01-01

    This capstone addresses an instructional gap in the Morehead State University Veterinary Technology Program and in other similar programs around the globe. Students do not retain the knowledge needed to proficiently complete suture patterns nor do students receive sufficient instructional time during the year to master each suture pattern that is…

  13. 21 CFR 878.4494 - Absorbable poly(hydroxybutyrate) surgical suture produced by recombinant DNA technology.

    Science.gov (United States)

    2010-04-01

    ... produced by recombinant DNA technology. 878.4494 Section 878.4494 Food and Drugs FOOD AND DRUG... recombinant DNA technology. (a) Identification. An absorbable poly(hydroxybutyrate) surgical suture is an...) Surgical Suture Produced by Recombinant DNA Technology.” For the availability of this guidance document...

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

    Science.gov (United States)

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

    2008-02-01

    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 mechanical loading are not well understood. This study was designed to investigate whether brief doses of tensile or compressive forces induce modeling and growth responses of intramembranous bone and sutures. In different groups of growing rabbits in vivo, cyclic tensile or compressive forces at 1 N and 8 Hz were applied to the maxilla for 20 min/day over 12 consecutive days. Computerized histomorphometric analyses revealed that the average sutural widths of both the premaxillomaxillary suture (PMS) and nasofrontal suture (NFS) loaded in either tension or compression were significantly higher than age- and sex-matched sham controls (P<0.01). The average cell densities of tension- or compression-loaded PMS and NFS were significantly higher than sham controls (P<0.01). The average osteoblast occupied sutural bone surface loaded under tension was significantly higher than that of sham control (P<0.05). Interestingly, tensile loading significantly reduced the average osteoclast surface, in comparison to sham control (P<0.05). For the NFS, tensile loading significantly increased the average osteoblast occupied sutural bone surface, in comparison with that of sham control (P<0.05). Also for the NFS suture, compression significantly reduced the average sutural osteoclast surface in comparison with sham control (P<0.05). Taken together, the present data suggest that high-frequency cyclic forces in either tension or compression induce modeling and growth changes in cranial sutures. Due to

  15. 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

  16. Robotic suture of a large caval injury caused by endo-GIA stapler malfunction during laparoscopic wedge resection of liver segments VII and VIII en-bloc with the right hepatic vein.

    Science.gov (United States)

    Boggi, Ugo; Moretto, Carlo; Vistoli, Fabio; D'Imporzano, Simone; Mosca, Franco

    2009-01-01

    Primary endo-GIA stapler malfunction occurred during robotic wedge resection of liver segments VII and VIII en-bloc with the right hepatic vein, in an obese woman diagnosed with single liver metastasis from a previous carcinoid tumour. Haemorrhage was soon controlled by clamping the vena cava below the injury using two wristed forceps angled at 90 degrees . With the two instruments locked in the holding position the ensuing operative strategy was discussed between surgeon and anaesthesia teams. Using the third robotic arm the caval injury was repaired laparoscopically with interrupted polypropylene sutures. The patient was transfused with two units of packed red blood cells, recovered uneventfully, and was discharged on post-operative day five. We conclude that even the most advanced technologies can fail and that surgeons should be fully aware of the consequences of these malfunctions and be prepared for repair. From this point of view, the da Vinci surgical system seems to have some advantages over classical laparoscopic methods including the ability to lock the wristed instruments in the holding position, the use of three arms by the same operating surgeon, and the extreme facilitation of intracorporeal suturing and knot-tying in deep and narrow spaces, extremely difficult if not impossible with conventional laparoscopic instruments.

  17. 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.

  18. [Refixation of sternoclavicular luxation with a suture anchor system].

    Science.gov (United States)

    Lehmann, W; Laskowski, J; Grossterlinden, L; Rueger, J M

    2010-05-01

    Luxations of the sternoclavicular joint are rare injuries. We present a case of anterior dislocation which was caused by a minor fall onto the right shoulder. Diagnosis was delayed by 2 weeks which prevented treatment by closed reduction. As an alternative surgical treatment a PDS cord around the clavicle and the first rib was used to stabilize the clavicle at the vertical level. Subsequently, fixation to the medial side was achieved by a suture anchor that was placed into the manubrium. The presented case highlights this simple and safe method to treat dislocations of the sternoclavicular joint in which standard treatment cannot be performed. A detailed description for each operation step is given and our experience in terms of aftercare and outcome is reported.

  19. The functional significance of the squamosal suture in Australopithecus boisei.

    Science.gov (United States)

    Rak, Y

    1978-07-01

    A juvenile Australopithecus boisei specimen from the Omo basin, southern Ethiopia, is found to exhibit and extraordinarily large overlap of the temporal squama on the parietal, a phenomenon shared with at least two adult specimens of A. boisei. An attempt is made to interpret the overlap as a structural (bony/ligamentous) adaptation necessitated by the unique combination of certain components of the masticatory system of A. boisei. These are: (1) the massiveness and strength of the temporalis muscle, (2) its relatively anterior location, and (3) the lateral position of the masseter muscle due to the flaring of the zygomatic arches. The effect of the temporalis muscle is to create excessive pressure on the portion of the squamosal suture along the parietal, while the lateral placement of the masseter and the resultant increase of pressure on the temporal squama via the zygomatic arch tend to "loosen" the contact between the temporal and parietal bones.

  20. Use and application of MADYMO 5.3 foam material model for expanded polypropylene foam

    NARCIS (Netherlands)

    Kant, A.R.; Suffis, B.; Lüsebrink, H.

    1998-01-01

    The dynamic material characteristics of expanded polypropylene are discussed. The in-depth studies, carried out by JSP International, in cooperation with TNO, are used to validate the MADYMO foam material model. The dynamic compression of expanded polypropylene follows a highly non-linear stress-str

  1. 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...

  2. 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...

  3. Improvement in compatibility and mechanical properties of modified wood fiber/polypropylene composites

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To improve the interfacial compatibility between wood fibers and polypropylene and the toughness of wood-fiber/polypropylene composites,maleic anhydride grafted polypropylene (PP-g-MAH) and maleic anhydride grafted styrene-ethylene-butadiene-styrene copolymers (SEBS-g-MAH) were used as modifiers.Mechanical properties of wood-fiber/polypropylene (WF/PP) composites were improved when PP-g-MAH or SEBS-g-MAH was added.When either of these copolymers was added,the composites had better interfacial compatibility than the unmodified composite.This was verified by scanning electron microscope (SEM) observations and dynamic mechanical analysis (DMA).The mechanical properties of the composites were significantly improved because of the good interfacial bonding between wood fibers and polypropylene when PP-g-MAH and SEBS-g-MAH were added.

  4. 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.

  5. INTERACTION BETWEEN THE SURFACE GLYCOSYLATED POLYPROPYLENE MEMBRANE AND LECTIN

    Institute of Scientific and Technical Information of China (English)

    Qian Yang; Ling-shu Wan; Zhi-kang Xu

    2008-01-01

    A glycopolymer bearing glucose residues was tethered onto the surface of polypropylene microporous membrane by UV-induced graft polymerization of α-allyl glucoside. Concanavalin A (Con A), a glucose recognizing lectin, could be specifically adsorbed to the membrane surface. On the other hand, the membrane surface showed no recognition ability to another lectin peanut agglutinin. Moreover, the recognition complex between the glycosylated membrane surface and Con Acould be inhibited by glucose and mannose solution. This surface glycosylated membrane could be used as affinity membrane for protein separation and purification.

  6. GRAFT COPOLYMERIZATION OF ACRYLAMIDE ONTO POLYPROPYLENE FILMS BY PLASMA TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    WANG Shicai; YE Mu; LU Lizhen; CHEN Jie

    1988-01-01

    The graft copolymerization of acrylamide onto polypropylene (PP) film was carried out by using a capacitively coupled rf plasma apparatus with external plate electrodes. The relationship between the surface structure of the Ar plasma-treated PP films and the extent of grafting of acrylamide on the films was studied through observing the effects of discharge power and exposure time on the relative content of free-radical on the film surface. Meanwhile, the wettability and surface energy of the PP film were measured.

  7. Radiation Damage of Polypropylene Fiber Targets in Storage Rings

    CERN Document Server

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

    2004-01-01

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

  8. Exciton migration and quenching in poly(propylene imine) dendrimers

    Science.gov (United States)

    Minevičiūtė, I.; Gulbinas, V.; Franckevičius, M.; Vaišnoras, R.; Marcos, M.; Serrano, J. L.

    2009-05-01

    Exciton migration between chromophore groups of the poly(propylene imine) dendrimer in chloroform solution and in solid state has been investigated by means of the time-resolved fluorescence measurements. Fluorescence decay kinetics, dynamic band shift and the depolarization rate have been analyzed. Exciton migration in a single dendrimer was found to be slow in comparison with temperature-dependent chromophore reorientation time of 150-600 ps. In a solid state chromophore groups form collective excitonic states responsible for the dendrimer film fluorescence. Exciton migration and localization to the lowest energy sites within the distributed density of states take place on a subnanosecond-nanosecond time scale.

  9. Rheological Behavior for Mica-filled Polypropylene Composite Melts

    Institute of Scientific and Technical Information of China (English)

    Yan Xia CAO; Miao DU; Qiang ZHENG

    2004-01-01

    The study on rheological properties of a series of mica-filled polypropylene ( PP ) composites was carried out. The influence of surface-treatment of mica particles on dynamic rheological behavior of the composites were dealt with. The viscosity ( η ) and dynamic modulus ( G′ ) of the composite melts were higher than those of PP matrix, especially those for systems treated with silane, which was attributed to the interfacial adhesion enhancement. However, surface-treatment of mica by titanate resulted in lower η and G′, as compared with the treatment by silane. The reason for this is believed to be the formation of the mono-molecular layer on the mica surface.

  10. Physical changes associated with gamma doses on Wood/ Polypropylene Composites

    Science.gov (United States)

    Ndiaye, Diène; Tidjani, Adams

    2014-08-01

    The effect of gamma- radiation on the morphology, thermal behavior and mechanical properties of wood polypropylene composites has been investigated. Simultaneous thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC) have been performed on WPC samples of (9.5 ± 0.1) mg. These samples were exposed to different gamma-dose in the range 10 to 100kGy. The results indicated that gamma radiation improves the mechanical properties while the thermal stability is decreased. With gamma radiation, the scanning electron microscopy (SEM) of the micrographs became smoother and we can notice an improvement of interaction between polymer and wood fibers.

  11. Toughening wood/polypropylene composites with polyethylene octene elastomer (POE)

    Institute of Scientific and Technical Information of China (English)

    JIANG Feng; QIN Te-fu

    2006-01-01

    Polyethylene octene elastomer (POE) as impact modifier was incorporated into wood/polypropylene composites (WPC) to enhance the impact strength of the composite. Two extruding routes, i.e. direct extruding route and two-stage extruding route, were adopted to produce Wood Powder/PP/POE ternary composites. The mechanical and dynamic mechanical analysis (DMA) properties of the composites were investigated. The results showed that the addition of POE can increase the impact strength of the composites, and the composites produced via two-stage extruding route showed superior mechanical properties. The results of the DMA confirmed the mechanical tests.

  12. Raman Spectroscopy of Isotactic Polypropylene-Halloysite Nanocomposites

    Directory of Open Access Journals (Sweden)

    Elamin E. Ibrahim

    2012-01-01

    Full Text Available Raman spectroscopy investigations on nanocomposites obtained by dispersing halloysite within isotactic polypropylene are reported. A detailed analysis of the modifications of the regularity band associated to the polymeric matrix is presented. The Raman lines assigned to the polymeric matrix are broadened and weakened as the loading with halloysite is increased. The analysis of Raman lines indicates that the polymeric matrix becomes less crystalline upon the loading with halloysite and that the nanofiller is experiencing a weak dehydration upon dispersion within the polymeric matrix, probably due to the related thermal processing used to achieve the dispersion of halloysite.

  13. Comparison of two different suture-passing techniques with different suture materials and thicknesses: Biomechanical study of flexor tendons for yield points, gap formation and early post-operative status

    Directory of Open Access Journals (Sweden)

    Volkan Ergan

    2016-12-01

    Conclusion: The yield points with higher forces is expected to be preferred, but their thicknesses can be 3-0 or 4-0. Oblique suture passing should be preferred rather than longitudinal passing. Obviously, suture strengthening methods, like epitendineous running sutures and core sutures, should be used. Without these measures, even passive wrist motion can result in gap formation at the repair site. The results of this study showed that tensile properties of the repaired vary considerably with differences in suture material and design. [Hand Microsurg 2016; 5(3.000: 130-136

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

    Science.gov (United States)

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

    2014-01-01

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

  15. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-15

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

  17. BCL11B expression in intramembranous osteogenesis during murine craniofacial suture development.

    Science.gov (United States)

    Holmes, Greg; van Bakel, Harm; Zhou, Xueyan; Losic, Bojan; Jabs, Ethylin Wang

    2015-01-01

    Sutures, where neighboring craniofacial bones are separated by undifferentiated mesenchyme, are major growth sites during craniofacial development. Pathologic fusion of bones within sutures occurs in a wide variety of craniosynostosis conditions and can result in dysmorphic craniofacial growth and secondary neurologic deficits. Our knowledge of the genes involved in suture formation is poor. Here we describe the novel expression pattern of the BCL11B transcription factor protein during murine embryonic craniofacial bone formation. We examined BCL11B protein expression at E14.5, E16.5, and E18.5 in 14 major craniofacial sutures of C57BL/6J mice. We found BCL11B expression to be associated with all intramembranous craniofacial bones examined. The most striking aspects of BCL11B expression were its high levels in suture mesenchyme and increasingly complementary expression with RUNX2 in differentiating osteoblasts during development. BCL11B was also expressed in mesenchyme at the non-sutural edges of intramembranous bones. No expression was seen in osteoblasts involved in endochondral ossification of the cartilaginous cranial base. BCL11B is expressed to potentially regulate the transition of mesenchymal differentiation and suture formation within craniofacial intramembranous bone.

  18. 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.)

  19. Effects of rapid maxillary expansion on the cranial and circummaxillary sutures

    Science.gov (United States)

    Ghoneima, Ahmed; Abdel-Fattah, Ezzat; Hartsfield, James; El-Bedwehi, Ashraf; Kamel, Ayman; Kula, Katherine

    2016-01-01

    Introduction The aim of this study was to determine whether the orthopedic forces of rapid maxillary expansion cause significant quantitative changes in the cranial and the circummaxillary sutures. Methods Twenty patients (mean age, 12.3 ± 1.9 years) who required rapid maxillary expansion as a part of their comprehensive orthodontic treatment had preexpansion and postexpansion computed tomography scans. Ten cranial and circummaxillary sutures were located and measured on one of the axial, coronal, or sagittal sections of each patient’s preexpansion and postexpansion computed tomography scans. Quantitative variables between the 2 measurements were compared by using the Wilcoxon signed rank test. A P value less than 0.05 was considered statistically significant. Results Rapid maxillary expansion produced significant width increases in the intermaxillary, internasal, maxillonasal, frontomaxillary, and frontonasal sutures, whereas the frontozygomatic, zygomaticomaxillary, zygomaticotemporal, and pterygomaxillary sutures showed nonsignificant changes. The greatest increase in width was recorded for the intermaxillary suture (1.7 ± 0.9 mm), followed by the internasal suture (0.6 ± 0.3 mm), and the maxillonasal suture (0.4 ± 0.2 mm). The midpalatal suture showed the greatest increase in width at the central incisor level (1.6 ± 0.8 mm) followed by the increases in width at the canine level (1.5 ± 0.8 mm) and the first molar level (1.2 ± 0.6 mm). Conclusions Forces elicited by rapid maxillary expansion affect primarily the anterior sutures (intermaxillary and maxillary frontal nasal interfaces) compared with the posterior (zygomatic interface) craniofacial structures. PMID:21967938

  20. 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).

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

    Directory of Open Access Journals (Sweden)

    Phimon Atsawasuwan

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

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

    DEFF Research Database (Denmark)

    Lynnerup, Niels; Jacobsen, Jens Christian Brings

    2003-01-01

    The fractal dimensions of human sagittal and coronal sutures were calculated on 31 complete skulls from the Terry Collection. The aim was to investigate whether the fractal dimension, relying on the whole sutural length, might yield a better description of age-related changes in sutural morphology......, as opposed to other methods of quantification, which generally rely on more arbitrary scoring systems. However, the fractal dimension did not yield better age correlations than other previously described methods. At best, the results reflected the general observation that young adults below age 40 years...

  3. Suture anchor repair of patellar tendon rupture after total knee arthroplasty.

    Science.gov (United States)

    Kamath, Atul F; Shah, Roshan P; Summers, Nathan; Israelite, Craig L

    2013-12-01

    Extensor mechanism disruption after total knee arthroplasty (TKA) is a complex problem that often requires surgical repair for functional deficits. We present a brief technical note on suture anchor fixation of a patellar tendon rupture after TKA. A surgical technique and literature review follows. Although suture anchor fixation is well described for tendinous repairs in other areas of orthopedic surgery, no study has discussed the use of suture anchors in patellar tendon repair after TKA. The technique must be evaluated in more patients with longer follow-up before adoption.

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

    Science.gov (United States)

    Cohen, M Michael

    2009-03-01

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

  5. THERMOCHROMIC EFFECTS OF LEUCO DYES STUDIED IN POLYPROPYLENE

    Institute of Scientific and Technical Information of China (English)

    Arno Seeboth; Detlef L(o)tzsch; Elvira Potechius; Renate Vetter

    2006-01-01

    A series of thermochromic polypropylene foils were prepared by embedding various leuco dye-developer-solvent systems in the polymer matrix. Bisphenol A, laurylgallate, ethylgallate and p-hydroxybenzoic acid methyl ester were used as developers, crystal violet lactone and 3,3-bis-(1-n-butyl-2-methyl-3-indolyl)-phthalide as dyes and 1-octanoic acid methyl ester as solvent. The molar ratio between the three components of the investigated leuco dye-developer-solvent systems was kept constant. All obtained polypropylene foils exhibit an excellent thermochromic behavior. The foils, prepared by extrusion technology, switch from color to colorless with increasing temperature. The influence of molecular structure of the developer on the intensity of the colored state and the influence of a developer-surfactant complex on the resulting thermochromic properties were investigated. The results are presented and discussed in detail according to a molecular model suggesting that the ring-opening process of the leuco dye is triggered by the formation of dye-developer complexes via H-bondings.

  6. 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.

  7. Reinforcement of Recycled Foamed Asphalt Using Short Polypropylene Fibers

    Directory of Open Access Journals (Sweden)

    Yongjoo Kim

    2013-01-01

    Full Text Available This paper presents the reinforcing effects of the inclusion of short polypropylene fibers on recycled foamed asphalt (RFA mixture. Short polypropylene fibers of 10 mm length with a 0.15% by weight mixing ratio of the fiber to the asphalt binder were used. The Marshall stability test, the indirect tensile strength test, the resilient modulus test, and wheel tracking test of the RFA mixtures were conducted. The test results were compared to find out the reinforcing effects of the inclusion of the fiber and the other mixtures, which included the conventional recycled foamed asphalt (RFA mixtures; the cement reinforced recycled foamed asphalt (CRFA mixtures; the semihot recycled foamed asphalt (SRFA mixtures; and recycled hot-mix asphalt (RHMA mixtures. It is found that the FRFA mixture shows higher Marshall stability than the RFA and SRFA mixtures, higher indirect tensile strength than the RFA mixture, and higher rut resistance than the RFA, SRFA, and RHMA mixtures as seen from the wheel tracking test.

  8. INTERFACE REACTION BETWEEN γ- AMINOPROPYLTRIMETHOXYSILANE AND ULTRAVIOLET IRRADIATED POLYPROPYLENE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The interface reaction between ultraviolet irradiated polypropylene(UV-PP) and an amino silane coupling agent, γ-aminopropyltrimethoxysilane (γ-APS) adsorbed on glass fibers has been investigated by means of the combining use of solvent extraction and FTIR as well as XPS. First, polypropylene (PP) physisorbed on the glass fibers surface was removed by the solvent extraction in order to minimize the effect of the PP siginal in FTIR and XPS analyses. Second, the remaining glass fibers after solvent extraction were analyzed by FTIR and XPS. The results show that the absorption bands of PP still exist in the FTIR spectrum and two new bands of N1s at 399.1eV and 401.6eV appear in the XPS spectrum for the composite with UV-PP and γ-APS treated glass fibers. Thus, the interface reaction between the UV-PP and γ-APS has been monitored directly. In addition, it may be concluded that OH and COOH groups of UV-PP form chemical bonds with NH2 group of γ-APS , respectively.

  9. SURFACE MODIFICATION OF POLYPROPYLENE MICROPOROUS MEMBRANE BY TETHERING POLYPEPTIDES

    Institute of Scientific and Technical Information of China (English)

    Zhen-mei Liu; Zhi-kang Xu; Mathias Ulbricht

    2006-01-01

    Two kinds of polypeptides were tethered onto the surface of polypropylene microporous membrane (PPMM)through a ring opening polymerization of L-glutamate N-carboxyanhydride initiated by amino groups which were introduced by ammonia plasma and γ-aminopropyl triethanoxysilane treatments. X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (FT-IR/ATR), scanning electron microscopy (SEM), together with water contact angle measurements were used to characterize the modified membranes. XPS analyses and FT-IR/ATR spectra demonstrated that polypeptides are actually grafted onto the membrane surface. The wettability of the membrane surface increases at first and then decreases with the increase in grafting degrees of polypeptide. Platelet adhesion and murine macrophage attachment experiments reveal an enhanced hemocompatibility for the polypeptide modified PPMMs. All these results give evidence that polypeptide grafting can simultaneously improve the hemocompatibility as well as reserve the hydrophobicity for the membrane, which will provide a potential approach to improve the performance of polypropylene hollow fiber microporous membrane used in artificial oxygenator.

  10. On engineering of properties of wood-polypropylene composite

    Directory of Open Access Journals (Sweden)

    Điporović Milanka

    2006-01-01

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

  11. An alternative tectonic model for the Yarlung Zangbo suture zone

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The new field investigations along the Yarlung Zangbo ophiolites zone show that these series underwent low green-schist metamorphism and were then fractured and occurred as slabs in tectonic melanges,without regional tectonic polarity.No large shear zone in north-south direction has been identified between ophiolite bodies and flysch layers on both side and a conformable contact relationship can be observed locally between them.A great mass of tectonic mélange has been substantiated as submarine olistolith bodies.The Mesozoic sedimentary facies and its evolution in both north and south of the ophiolite zone are corresponding in time.The ophiolite zone has often been divided into parallel branches,separated by narrow flysch slats.There is also a similarity of the Paleozoic and the basement of the High Himalaya,Lhasa and Qiangtang Terranes,and they are distinctly different from those of the Indian continent.The geologic information does not warrant a postulate that the Himalaya and Tibet were once separated by a great ocean;it is therefore consistent with an alternative tectonic model by back-arc basin collapse with its juvenile narrow oceanic crust.The real plate tectonic suture,the Neotethys might be covered under the Miocene Siwalik molasse in the southern slope of the High Himalaya range.Based on the new model,the Neotethyan ocean floor was subducted beneath the Asia since the Late Triassic.The outer continental margin of Eurasia was split from the Lhasa Terrane so that a back-arc basin came into existence.Hemi-pelagic and deep sea sediments were deposited before the Late Cretaceous flysch sedimentation,with the linear juvenile oceanic crust when back-arc volcanism occurred in the Gandese region.The Yarlung Zangbo back-arc basin was eventually eliminated when the High Himalayas were sutured onto Eurasia.The ocean floor lightly underthrusted to north and south sides,sediments of the basin were deformed as fold-thrusting.The Neotethys was eliminated during the

  12. Fixation in laparoscopic incisional hernia repair: Suture versus tacks

    Directory of Open Access Journals (Sweden)

    Adil Bangash

    2013-01-01

    Full Text Available Aims and Objectives: To compare the frequency of complications of laparoscopic repair of incisional hernia using fixation of mesh with transabdominal sutures tacks. Materials and Methods: This study was conducted as part of an interventional multicenter trial at the Rehman Medical Institute, Peshawar, Peshawar Institute of Medical Sciences, and Pakistan Institute of Medical Science, Islamabad, from the 1 st of November 2008 till 31 st October 2011. The frequency of complications was calculated as the measure of comparing two methods of fixation in laparoscopic repair of incisional hernia using the IPOM technique. These patients were admitted via the outpatient department and their demographic data were collected on a pro forma basis. Forty-five patients were alternately placed in either group, and group I comprised patients with a ventral hernia that was fixed using spiral tacks whereas the other group was fixed with transabdominal sutures. A polytetraflouroethylene (Dual R mesh was applied in all cases. All data were collected onthe individual pro forma of each patient and was loaded on the SPSS R version 13.0. Results: The BMI in both groups was similar (P=0.94 The mean hospital stay was higher in the PTFE mesh group but the values were not significant (P=1.22.No perioperative death was observed in either group. One patient (2.2% from group I was readmitted with varying complaints and was diagnosed as having subacute intestinal obstruction (P>0.05. A higher but insignificant recurrence rate was observed in the polyester group over a one-year period of follow-up. Three patients (6.6% were diagnosed with recurrences in group I. Instead the PTFE group had a similar recurrence rate recurrence (P=1.00. Conclusion: The rate of recurrence in this study showed no significant difference by either mode of fixation. But statistically significant pain scores and increased operative time to fixation favors the use of tacks that limits to the few inner

  13. Radiation-induced grafting of acrylic acid onto polypropylene film and its biodegradability

    Science.gov (United States)

    Mandal, Dev K.; Bhunia, Haripada; Bajpai, Pramod K.; Chaudhari, C. V.; Dubey, K. A.; Varshney, L.

    2016-06-01

    Polypropylene based commodity polyolefins are widely used in packaging, manufacturing, electrical, pharmaceutical and other applications. The aim of the present work is to study the effect of grafting of acrylic acid on the biodegradability of acrylic acid grafted polypropylene. The effect of different conditions showed that grafting percentage increased with increase in monomer concentration, radiation dose and inhibitor concentration but decreased with increase in radiation dose rate. The maximum grafting of 159.4% could be achieved at optimum conditions. The structure of grafted polypropylene films at different degree of grafting was characterized by EDS, FTIR, TGA, DSC, SEM and XRD. EDS studies showed that the increase in acrylic acid grafting percentage increased the hydrophilicity of the grafted films. FTIR studies indicated the presence of acrylic acid on the surface of polypropylene film. TGA studies revealed that thermal stability decreased with increase in grafting percentage. DSC studies showed that melting temperature and crystallinity of the grafted polypropylene films lower than polypropylene film. SEM studies indicated that increase in acrylic acid grafting percentage increased the wrinkles in the grafted films. The maximum biodegradability could be achieved to 6.85% for 90.5% grafting. This suggested that microorganisms present in the compost could biodegrade acrylic acid grafted polypropylene.

  14. 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.

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

    Science.gov (United States)

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

    2016-03-01

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

  16. A Study of the Kunlun-Qilian-Qinling Suture System

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Late Neoproterozoic-Early Palaeozoic suture zones within theCentral Orogenic Belt of China can be considered a system-the Kunlun-Qilian-Qinling suture system (KQQ suture system). It is basically divided into the western, central and eastern sectors. The western sector consists of the Küda-Subashi suture zone, the Mazar Kangxiwar suture and the central West Kunlun microblock. The central sector covers the following five suture zones: the Altun, North Qilian, Qaidam northern marginal, Qimantag-Wutuo and East Kunlun southern marginal sutures, in addition to some microblocks such as the mid-south Qilian, Qaidam, Ayakkum and Maqen microblocks. The eastern sector is composed of the Shangdan suture zone, Mianlüe suture zone and central Qinling-Dabie microblock. The KQQ suture system experienced (1) extending-rifting of the Rodinia super-continent in the early-middle Sinian (~780-600 Ma); (2) the formation and evolution of the KQQ archipelagic ocean during the Late Sinian-Ordovician (~600-440 Ma), and (3) closing of the KQQ ocean and forming of the KQQ suture system during the Late Ordovician-early Silurian (~440-400 Ma). As a system comprising many suture zones and microblocks, the KQQ suture system consti tutes the foundation of the Central Orogenic Belt of China.CLC Number:P5 Document ID:Afoundation Item:This study was supported by the National Natural Science Foundation of China (grants 49872077 and 49572153), and the Lu Jiaxi Foundation of the Chinese Academy of Sciences.Author Resume:Bian Qiantao Born in 1945; graduated from the Department of Geology, South-Central University of Technology in 1970, and obtained his master's degree and doctor's degree at the Graduate School and the Institute of Geology, Chinese Academy of Sciences in 1981 and 1987, respectively. He is currently a professor of the Institute of Geology and Geophysics, Chinese Academy of Sciences, and has long been engaged in the research of tectonics, petrology, mineral deposits and

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

    Science.gov (United States)

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

    2016-02-01

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

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

    Science.gov (United States)

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

    2008-01-01

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

  19. Glottal configuration, acoustic, and aerodynamic changes induced by variation in suture direction in arytenoid adduction procedures.

    Science.gov (United States)

    Inagi, Katsuhide; Connor, Nadine P; Suzuki, Tatsutoshi; Ford, Charles N; Bless, Diane M; Nakajima, Masami

    2002-10-01

    Arytenoid adduction is a phonosurgical procedure in which the arytenoid cartilages are approximated to reduce posterior glottal gap size and improve voice. Voice outcomes following arytenoid adduction are not always optimal. The goal of this study was to systematically vary suture direction and force of pull on the arytenoid cartilages in a human excised laryngeal model to determine the optimal combination of factors for reducing glottal gap and improving voice. Several factors demonstrated significant effects. Changes in suture direction and force of pull affected glottal configuration in both the horizontal and vertical planes. Increased force of pull on the muscular process resulted in increased adduction of the vocal process for all suture directions. Changes in suture direction and force of pull also affected acoustic and aerodynamic measures of induced voice. Therefore, voice outcomes can be optimized with arytenoid adduction if the vocal fold plane is accurately adjusted.

  20. Electrosurgical bipolar vessel sealing versus conventional clamping and suturing for total abdominal hysterectomy: a randomized trial.

    NARCIS (Netherlands)

    Lakeman, M.; Kruitwagen, R.F.P.M.; Vos, M.C.; Roovers, J.P.

    2008-01-01

    STUDY OBJECTIVE: To compare the effects of bipolar vessel sealing versus conventional clamping and suturing in women undergoing total abdominal hysterectomy. DESIGN: A randomized controlled trial was performed. Patients were randomized to vessel sealing or conventional surgery. Postoperative pain wa

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

    Institute of Scientific and Technical Information of China (English)

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

    2014-01-01

    Craniosynostosis is a pathologic condition which is characterized by the premature fusion of cranial sutures.It may occur alone or in association with other anomalies making up various syndromes.Crouzon syndrome is the most common craniosynostosis syndrome.Bicoronal sutures fusion is most commonly involved in Crouzon syndrome.There have only been a handful of cases of squamosal suture synostosis described in the surgery literature with the few ones described in Crouzon syndrome associated with other types of craniosynostosis.To the best of our knowledge,we are presenting the first case of isolated bilateral squamosal suture synostosis in a patient with Crouzon syndrome in a radiology journal with emphasis on its radiological appearance.

  2. Effect of Electrostatic Reduced-Gravity Environment on the Crystallographic Parameters of elt-Crystallized Polypropylene

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    An electrostatic reduced-gravity device was developed and used specially for the study of the melt crystal-lization of polypropylene. The crystal structure of melt-crystallized polypropylene prepared under the reduced-gravityenvironment was investigated by using X-ray diffraction. The experiment results show that the crystal structure ofthe polypropylene is strongly dependent on the gravity applied to the sample during solidification. It is found that thecrystallographic parameters a and b increase markedly with reduced-gravity ratio, while the value of c increasesmildly.

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

    Directory of Open Access Journals (Sweden)

    Deng Fukang

    2013-07-01

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

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

    Directory of Open Access Journals (Sweden)

    R. S. Rajguru,

    2014-06-01

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

  5. Acute distal tibiofibular syndesmosis injury: A systematic review of suture-button versus syndesmotic screw repair

    OpenAIRE

    Schepers, Tim

    2012-01-01

    textabstractPurpose: Recently, a new suture-button fixation device has emerged for the treatment of acute distal tibiofibular syndesmotic injuries and its use is rapidly increasing. The current systematic review was undertaken to compare the biomechanical properties, functional outcome, need for implant removal, and the complication rate of syndesmotic disruptions treated with a suture-button device with the current 'gold standard', i.e. the syndesmotic screw. Method: A literature search in t...

  6. Post-Operative Pancreatic Fistula in Pancreatico-Duodenectomy with Pancreato-Gastrostomy using Barbed Sutures

    OpenAIRE

    2016-01-01

    Objective To demonstrate safety of barbed sutures for pancreatogastrostomy after pancreaticoduodenectomy, analyzing our results with worldwide literature exclusively about post-operative pancreatic fistula, according to the International Study Group for Pancreatic Fistula definition. Methods From 1st January 2013 to 30th June 2015, 39 patients underwent pancreaticoduodenectomy with PG reconstruction (but only 36 using barbed sutures). We evaluated demographic details of the patients (age, sex...

  7. Visibility of Sutures of the Orbit and Periorbital Region Using Multidetector Computed Tomography

    OpenAIRE

    2014-01-01

    Objective 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. Materials and Methods 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...

  8. Clinical inquiries. How does tissue adhesive compare with suturing for superficial lacerations?

    Science.gov (United States)

    Aukerman, Douglas F; Sebastianelli, Wayne J; Nashelsky, Joan

    2005-04-01

    Tissue adhesives are effective and yield results comparable to those with conventional suturing of superficial, linear, and low-tension lacerations. The cosmetic outcome is similar; wound complications, such as infection and dehiscence, may be lower with tissue adhesives. Wound closure of superficial lacerations by tissue adhesives is quicker and less painful compared with conventional suturing (strength of recommendation: A, systematic reviews of randomized trials).

  9. No-drain DIEP Flap Donor-site Closure Using Barbed Progressive Tension Sutures

    OpenAIRE

    Nagarkar, Purushottam; Lakhiani, Chrisovalantis; Cheng, Angela; Lee, Michael; Teotia, Sumeet; Saint-Cyr, Michel

    2016-01-01

    Background: The use of progressive tension sutures has been shown to be comparable to the use of abdominal drains in abdominoplasty. However, the use of barbed progressive tension sutures (B-PTSs) in deep inferior epigastric artery perforator (DIEP) flap donor-site closure has not been investigated. Methods: A retrospective chart review was performed on patients with DIEP flap reconstruction in a 3-year period at 2 institutions by 2 surgeons. Patients were compared by method of DIEP donor-sit...

  10. [Application and development of suture-dragging therapy for anal fistula].

    Science.gov (United States)

    Wang, Chen; Yao, Yibo; Dong, Qingjun; Liang, Hongtao; Guo, Xiutian; Cao, Yongqing; Lu, Jingen

    2015-12-01

    Traditional Chinese surgical treatment "suture-dragging" therapy is based on medical thread therapy and tight seton drainage in combination of minimal invasive surgical principle. It can preserve the integrity of anal sphincter musculature involved in fistulous tract or abscess and maintain anal function. This article not only describes in detail about the operation points and mechanisms of "suture-dragging" therapy of anorectal fistula, but also reviews the application and modification of anorectal disease.

  11. Kestenbaum procedure with posterior fixation suture for anomalous head posture in infantile nystagmus

    OpenAIRE

    2009-01-01

    Background The purpose of this study was to report the effect of combining the Kestenbaum procedure with posterior fixation suture for infantile horizontal nystagmus with anomalous head posture (AHP) in children. Methods Nine consecutive patients who underwent combined Kestenbaum procedure plus posterior fixation suture to the recessed muscles at the same time were retrospectively studied. All patients were orthotropic before surgery and were followed for at least 6 months. Pre- and postopera...

  12. 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.

  13. [Mechanical suture during resection of the rectum through the abdomen (author's transl)].

    Science.gov (United States)

    Gauthier-Benoît, C; Prat, A

    1979-01-01

    A mechanical suture using the URSS PKZ 28 or SPTU stapler was used in 30 low colo-rectal anastomoses. There were two deaths related to anastomotic complications. It is safe to establish a colostomy when the colon is not well prepared. Fistulae are frequent after palliative operations: this is a poor indication. Local recurrences are no more frequent with stapling than with manual suture.

  14. [Iris suture fixation of posterior-chamber elastic intraocular lens in ligament apparatus laxity].

    Science.gov (United States)

    Pashtaev, N P; Bat'kov, E N; Zotov, V V

    2010-01-01

    An original MIOL-23 multifocal elastic intraocular lens (IOL) was used to operate 5 eyes with acquired lens dislocation and traumatic cataract. By making self-sealing tunnel incision, ILO was implanted into the capsular sac and sutured to the iris. MIOL-23 implantation caused an increase in mean visual acuity. The IOL took up a correct position. Elastic IOL implantation with iris suture fixation is an efficient and safe mode of additional ILO support.

  15. Toughening mechanisms in discontinuous glass/polypropylene composites

    Science.gov (United States)

    Williams, Eunethia Denise

    1997-08-01

    There are five energy absorbing mechanisms for discontinuous fiber reinforced composites. These include fiber debonding, fiber pullout/bridging, fiber breakage, matrix cracking and matrix deformation. Because of the typically random orientation of fibers in these systems, it has been difficult to develop an experimental approach to determine which of these contributions dominate the measured in-plane toughness values. To address this issue, a specimen has been developed of one pultruded sheet of polypropylene-glass longitudinally centered in a compression molded polypropylene bar. Experimentally, interface strength was varied from weak to intermediate to strong adhesion through the addition of different sizings and maleic anhydride grafted polypropylene. The pullout contribution was determined through varying fiber length. Matrix contributions were determined by changing the molecular weight of the matrix and by changing the crystal structure from predominantly the alpha form to the beta form. Experiments of Izod testing have shown that impact strength is maximized in specimens with a weak interface at an optimum fiber length corresponding to the fiber length at which pullout predominates. In specimens with an intermediate strength interface, impact strength showed a maximum but was reduced. In specimens with a strong interface, impact strength was the lowest and fairly level. Experiments of tensile testing also showed maximum toughness in specimens with a weak interface with an optimum fiber length where pull out predominates. In specimens with a strong interface, tensile toughness was reduced. Examination of these specimens suggests that the impact strength is maximized by the density via the crystallinity of the resin. The density influences the volume contraction of the matrix around the fibers during cooling. This volume contraction creates a radial stress on the fibers that affects the frictional shear stress against which the fibers are pulled out during

  16. The Double-Row Suture Technique: A Better Option for the Treatment of Haglund Syndrome.

    Science.gov (United States)

    Jiang, Yiqiu; Li, Yang; Tao, Tianqi; Li, Wang; Zhang, Kaibin; Gui, Jianchao; Ma, Yong

    2016-01-01

    Purpose. The purpose of this study is to investigate whether double-row suture technique is a better option for the treatment of Haglund syndrome than single-row suture technique regarding the surgical outcomes. Methods. Thirty-two patients with Haglund syndrome were recruited in this study. Patients were divided into Group 1 (treated with single-row suture technique) and Group 2 (treated with double-row suture technique). There were 16 patients in each group. The AOFAS-ankle-hindfoot scale, VISA-A scores, and Arner-Lindholm standard were used to assess the clinical outcomes. The pre- and postoperative X-rays were used to assess the radiological outcome. Results. Both AOFAS-ankle-hindfoot scale score and VISA-A score had varying degrees of improvement in both groups. In latest follow-up assessment, the Arner-Lindholm standard investigation showed there were 7 excellent, 7 good, and 2 bad outcomes in Group 1 and 12 excellent and 4 good outcomes in Group 2. In Group 2 patients, there were no more posterosuperior bony prominence of the calcaneum in post-op X-rays and there were no recurrent cases. The ankle-related scale score was statistically significantly higher in Group 2 than in Group 1 (P = 0.029). Conclusion. The double-row suture technique seems to be a better option to treat Haglund syndrome than single-row suture technique.

  17. The Double-Row Suture Technique: A Better Option for the Treatment of Haglund Syndrome

    Directory of Open Access Journals (Sweden)

    Yiqiu Jiang

    2016-01-01

    Full Text Available Purpose. The purpose of this study is to investigate whether double-row suture technique is a better option for the treatment of Haglund syndrome than single-row suture technique regarding the surgical outcomes. Methods. Thirty-two patients with Haglund syndrome were recruited in this study. Patients were divided into Group 1 (treated with single-row suture technique and Group 2 (treated with double-row suture technique. There were 16 patients in each group. The AOFAS-ankle-hindfoot scale, VISA-A scores, and Arner-Lindholm standard were used to assess the clinical outcomes. The pre- and postoperative X-rays were used to assess the radiological outcome. Results. Both AOFAS-ankle-hindfoot scale score and VISA-A score had varying degrees of improvement in both groups. In latest follow-up assessment, the Arner-Lindholm standard investigation showed there were 7 excellent, 7 good, and 2 bad outcomes in Group 1 and 12 excellent and 4 good outcomes in Group 2. In Group 2 patients, there were no more posterosuperior bony prominence of the calcaneum in post-op X-rays and there were no recurrent cases. The ankle-related scale score was statistically significantly higher in Group 2 than in Group 1 (P=0.029. Conclusion. The double-row suture technique seems to be a better option to treat Haglund syndrome than single-row suture technique.

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

    Directory of Open Access Journals (Sweden)

    Gazivoda Dragan

    2015-01-01

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

  19. 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

  20. Virtual reality robotic surgery simulation curriculum to teach robotic suturing: a randomized controlled trial.

    Science.gov (United States)

    Kiely, Daniel J; Gotlieb, Walter H; Lau, Susie; Zeng, Xing; Samouelian, Vanessa; Ramanakumar, Agnihotram V; Zakrzewski, Helena; Brin, Sonya; Fraser, Shannon A; Korsieporn, Pira; Drudi, Laura; Press, Joshua Z

    2015-09-01

    The objective of this randomized, controlled trial was to assess whether voluntary participation in a proctored, proficiency-based, virtual reality robotic suturing curriculum using the da Vinci(®) Skills Simulator™ improves robotic suturing performance. Residents and attending surgeons were randomized to participation or non-participation during a 5 week training curriculum. Robotic suturing skills were evaluated before and after training using an inanimate vaginal cuff model, which participants sutured for 10 min using the da Vinci(®) Surgical System. Performances were videotaped, anonymized, and subsequently graded independently by three robotic surgeons. 27 participants were randomized. 23 of the 27 completed both the pre- and post-test, 13 in the training group and 10 in the control group. Mean training time in the intervention group was 238 ± 136 min (SD) over the 5 weeks. The primary outcome (improvement in GOALS+ score) and the secondary outcomes (improvement in GEARS, total knots, satisfactory knots, and the virtual reality suture sponge 1 task) were significantly greater in the training group than the control group in unadjusted analysis. After adjusting for lower baseline scores in the training group, improvement in the suture sponge 1 task remained significantly greater in the training group and a trend was demonstrated to greater improvement in the training group for the GOALS+ score, GEARS score, total knots, and satisfactory knots.

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

    Science.gov (United States)

    Geiger, Madeleine; Haussman, Sinah

    2016-04-01

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

  2. The Development of the Calvarial Bones and Sutures and the Pathophysiology of Craniosynostosis.

    Science.gov (United States)

    Ishii, Mamoru; Sun, Jingjing; Ting, Man-Chun; Maxson, Robert E

    2015-01-01

    The skull vault is a complex, exquisitely patterned structure that plays a variety of key roles in vertebrate life, ranging from the acquisition of food to the support of the sense organs for hearing, smell, sight, and taste. During its development, it must meet the dual challenges of protecting the brain and accommodating its growth. The bones and sutures of the skull vault are derived from cranial neural crest and head mesoderm. The frontal and parietal bones develop from osteogenic rudiments in the supraorbital ridge. The coronal suture develops from a group of Shh-responsive cells in the head mesoderm that are collocated, with the osteogenic precursors, in the supraorbital ridge. The osteogenic rudiments and the prospective coronal suture expand apically by cell migration. A number of congenital disorders affect the skull vault. Prominent among these is craniosynostosis, the fusion of the bones at the sutures. Analysis of the pathophysiology underling craniosynostosis has identified a variety of cellular mechanisms, mediated by a range of signaling pathways and effector transcription factors. These cellular mechanisms include loss of boundary integrity, altered sutural cell specification in embryos, and loss of a suture stem cell population in adults. Future work making use of genome-wide transcriptomic approaches will address the deep structure of regulatory interactions and cellular processes that unify these seemingly diverse mechanisms.

  3. Influence of different types of surgical suture material on the intensity of tissue reaction in oral cavity

    Directory of Open Access Journals (Sweden)

    Mirković Siniša M.

    2008-01-01

    Full Text Available Throughout the history the most diverse suture material have been used for closing and suturing surgical wounds. The four basic features of suture material are described: knot safety, stretch capacity, tissue reactivity and wound safety. Tissue reaction, even the minimum one, which develops during the first to seven days after applying the suture in the tissue. The aim of this study was to investigate influence of a monofilament suture material (nylon on the intensity of local tissue reaction in experimental conditions, and to compare it with the multifilament suture used in the routine practice of oral surgery (silk. This investigation is a prospective experimental study carried out on Wistar rats. The experiment included 30 animals, in which Black Silk (thickness 4-1 and Nylon (thickness 4-0 were applied in the upper and lower jaw, respectively. To monitor tissue reaction on different suture materials the following parameters were used: coagulum formation, presence of polymorphonuclear leukocytes, presence of macrophages and granuloma, formation of epithelial bridge and connective tissue, collagen synthesis, granulomatous tissue formation and presence of fibrous tissue. After comparing parameters for the intensity of tissue reaction to the investigate suture materials by suturing the oral mucosa, certain advantage could be given to the monofilament suture materials.

  4. 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.

  5. 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.

  6. Polymorphic Behavior of Syndiotactic Polypropylene Induced by Heat Treatment

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The polymorphic behavior of syndiotactic polypropylene (s-PP) crystallized from the melt under different conditions was investigated by means of WAXD and DSC. The isothermal melt crystallization of s-PP proceeded in form I at tc≥110 ℃ and in form Ⅱ at tc<110 ℃. S-PP crystallized nonisothermally from the melt was the mixture of forms Ⅰ and Ⅱ. With increasing the cooling rate(a), the content of form I increased, and the content of form Ⅱ decreased. On heating, at 10 K/min, of quenched s-PP, it crystallized in form Ⅱ at t<70 ℃, continuing heating resulted in form Ⅱ→form I transition, which was an endothermal process.

  7. Preparation of polypropylene thermoplastic container via thermoforming process

    Science.gov (United States)

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

    2016-02-01

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

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

    DEFF Research Database (Denmark)

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

    1999-01-01

    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/PP and glass-fibre/ MA-PP coupons. The macroscopic fatigue behaviour was characterized in terms...... of stiffness reduction and fatigue-life curves. The results showed that the longitudinal Young's modulus degraded more rapidly for glass-fibre/PP, which was caused by a higher degree of damage growth and accumulation. The improvement in monotonic strength was negligible, but the fatigue life was prolonged...... by about one decade for the composite with the stronger interface by use of the maleic-anhydride grafted polypropylene matrix. During the fatigue testing, the microscopic mechanisms were monitored intermittently by a surface replication technique. From microscopic observations, it could be concluded...

  9. Light weight polarized polypropylene foam for noise shielding

    Science.gov (United States)

    Zelfer, Travis J.; Warne, Derik S.; Korde, Umesh A.

    2009-03-01

    The high levels of noise generated during launch can destroy sensitive equipment on space craft. Passive damping systems, like acoustic blankets, work to reduce the high frequency noise but do little to the low frequency noise (foams with high piezoelectric coupling constants are being used as new types of actuators and sensors. Further impedance control through the inverse piezoelectric effect will lead to a new "semi-active" approach that will reduce low frequency noise levels. Combining layers of conventional nonpiezoelectric foam and ferroelectret materials with a multiple loop feedback system will give a total damping effect that is adaptable over a wide band of low frequencies. This paper covers the manufacturing methods that were used to make polarized polypropylene foam, to test the foam for its polarized response and its noise shielding ability.

  10. Electrical properties of foamed polypropylene/carbon black composites

    Science.gov (United States)

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

    2016-02-01

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

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

    DEFF Research Database (Denmark)

    Jankova Atanasova, Katja; Daugaard, Anders Egede; Stribeck, Norbert;

    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 Kra...... 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....... 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...

  12. MARTINI Coarse-Grained Models of Polyethylene and Polypropylene.

    Science.gov (United States)

    Panizon, Emanuele; Bochicchio, Davide; Monticelli, Luca; Rossi, Giulia

    2015-06-25

    The understanding of the interaction of nanoplastics with living organisms is crucial both to assess the health hazards of degraded plastics and to design functional polymer nanoparticles with biomedical applications. In this paper, we develop two coarse-grained models of everyday use polymers, polyethylene (PE) and polypropylene (PP), aimed at the study of the interaction of hydrophobic plastics with lipid membranes. The models are compatible with the popular MARTINI force field for lipids, and they are developed using both structural and thermodynamic properties as targets in the parametrization. The models are then validated by showing their reliability at reproducing structural properties of the polymers, both linear and branched, in dilute conditions, in the melt, and in a PE-PP blend. PE and PP radius of gyration is correctly reproduced in all conditions, while PE-PP interactions in the blend are slightly overestimated. Partitioning of PP and PE oligomers in phosphatidylcholine membranes as obtained at CG level reproduces well atomistic data.

  13. Study of gel formation by ionizing radiation in polypropylene

    Science.gov (United States)

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

    2013-03-01

    The objective of this work is to study the formation of microgel in pristine PP and modified PP. The modified PP in pellets was synthesized by gamma irradiation of pristine PP under a crosslinking atmosphere of acetylene in different doses of 5, 12.5 and 20 kGy, followed by thermal treatment for radical recombination and annihilation of the remaining radicals. The gel content of the modified polypropylenes was determined by extraction in boiling xylene for period of 12 h at 138 °C. The gel formed of pristine PP and modified (i.e., irradiated) was characterized using optical microscopy (OM), scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR) and X-ray diffraction (XDR). The PP morphological study indicated the microgel formation with increase of spherulitic concentration with dose.

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

    Directory of Open Access Journals (Sweden)

    Marianna LAKA

    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

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    M. Antunes

    2010-01-01

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

  17. Thermal Degradation and Combustion Behavior of Polypropylene/MWCNT Composites

    Science.gov (United States)

    Zaikov, G. E.; Rakhimkulov, A. D.; Lomakin, S. M.; Dubnikova, I. L.; Shchegolikhin, A. N.; Davidov, E. Ya.

    2010-06-01

    Studies of thermal and fire-resistant properties of the polypropylene/multi-walled carbon nanotube composites (PP/MWCNT) prepared by means of melt intercalation are discussed. The sets of the data acquired with the aid of non-isothermal TG experiments have been treated by the model kinetic analysis. The thermal-oxidative degradation behavior of PP/MWCNT and stabilizing effect caused by addition of MWCNT has been investigated by means of TGA and EPR spectroscopy. The results of cone calorimetric tests lead to the conclusion that char formation plays a key role in the mechanism of flame retardation for nanocomposites. This could be explained by the specific antioxidant properties and high thermal conductivity of MWCNT which determine high-performance carbonization during thermal degradation process. Comparative analysis of the flammability characteristics for PP-clay/MWCNT nanocomposites was provided in order to emphasize the specific behavior of the nanocomposites under high-temperature tests.

  18. Properties of lightweight cement-based composites containing waste polypropylene

    Science.gov (United States)

    Záleská, Martina; Pavlíková, Milena; Pavlík, Zbyšek

    2016-07-01

    Improvement of buildings thermal stability represents an increasingly important trend of the construction industry. This work aims to study the possible use of two types of waste polypropylene (PP) for the development of lightweight cement-based composites with enhanced thermal insulation function. Crushed PP waste originating from the PP tubes production is used for the partial replacement of silica sand by 10, 20, 30, 40 and 50 mass%, whereas a reference mixture without plastic waste is studied as well. First, basic physical and thermal properties of granular PP random copolymer (PPR) and glass fiber reinforced PP (PPGF) aggregate are studied. For the developed composite mixtures, basic physical, mechanical, heat transport and storage properties are accessed. The obtained results show that the composites with incorporated PP aggregate exhibit an improved thermal insulation properties and acceptable mechanical resistivity. This new composite materials with enhanced thermal insulation function are found to be promising materials for buildings subsoil or floor structures.

  19. Experimental study on behaviors of polypropylene fibrous concrete beams

    Institute of Scientific and Technical Information of China (English)

    SUJI D.; NATESAN S.C.; MURUGESAN R.

    2007-01-01

    Synthetic fibers made from nylon or polypropylene have gained application when loose and woven into geo textile form although no information on the matrix's mechanical performance is obtained so that more understanding of their structural contribution to resist cracking can be determined. This paper presents the results of an experimental investigation to determine the performance characteristics of concrete reinforced with a polypropylene structural fiber. In this investigation "Fiber mesh" brand of fibers manufactured by SL Concrete System, Tennessee, USA and marketed by M/S Millennium Building System, Inc., Bangalore, India are used. The lengths of the fibers used were 24 mm. Fiber dosages used were 0.9, 1.8, 2.7 kg/m3. A total of three mixtures, one for each fiber dosage were made. A standard slump cone test was conducted on the fresh concrete mix with and without fibers to determine the workability of the mix. The test program included the evaluation of hardened concrete properties such as compressive, split tensile, modulus of rupture and flexural strengths. The increase in compressive strength is about 36.25%,26.20%, and 23.75% respectively that of plain concrete. This increase in strength was directly proportional to amount of fibers present in the mix. The increase in flexural strength for Mixes Ⅰ~Ⅲ is about 21%, 16.6%, and 23% respectively that of plain concrete specimens. An experimental investigation was also made to study the behaviors of reinforced fibers concrete beams (with longitudinal reinforcements) under two-point loading. The deflection and crack patterns were also studied. The improvements in strength and ductility characteristics were discussed.

  20. Evaluation of Thermally Induced Degradation of Branched Polypropylene by Using Rheology and Different Constitutive Equations

    Directory of Open Access Journals (Sweden)

    Jiri Drabek

    2016-08-01

    Full Text Available In this work, virgin as well as thermally degraded branched polypropylenes were investigated by using rotational and Sentmanat extensional rheometers, gel permeation chromatography and different constitutive equations. Based on the obtained experimental data and theoretical analysis, it has been found that even if both chain scission and branching takes place during thermal degradation of the tested polypropylene, the melt strength (quantified via the level of extensional strain hardening can increase at short degradation times. It was found that constitutive equations such as Generalized Newtonian law, modified White-Metzner model, Yao and Extended Yao models have the capability to describe and interpret the measured steady-state rheological data of the virgin as well as thermally degraded branched polypropylenes. Specific attention has been paid to understanding molecular changes during thermal degradation of branched polypropylene by using physical parameters of utilized constitutive equations.

  1. 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.

  2. Morphology and crystalline-phase-dependent electrical insulating properties in tailored polypropylene for HVDC cables

    Science.gov (United States)

    Zha, Jun-Wei; Yan, Hong-Da; Li, Wei-Kang; Dang, Zhi-Min

    2016-11-01

    Polypropylene (PP) has become one promising material to potentially replace the cross-link polyethylene used for high voltage direct current cables. Besides the isotactic polypropylene, the block polypropylene (b-PP) and random polypropylene (r-PP) can be synthesized through the copolymerization of ethylene and propylene molecules. In this letter, the effect of morphology and crystalline phases on the insulating electrical properties of PP was investigated. It was found that the introduction of polyethylene monomer resulted in the formation of β and γ phases in b-PP and r-PP. The results from the characteristic trap energy levels indicated that the β and γ phases could induce deep electron traps which enable to capture the carriers. And the space charge accumulation was obviously suppressed. Besides, the decreased electrical conductivity was observed in b-PP and r-PP. It is attributed to the existence of deep traps which can effectively reduce the carrier mobility and density in materials.

  3. 化学交联模压发泡聚丙烯的研究%The Study of the Chemical Crosslinked and Mould Pressing Foamed Polypropylene

    Institute of Scientific and Technical Information of China (English)

    杨霄云; 王爱东

    2011-01-01

    以一步模压工艺,采取化学交联法发泡聚丙烯(PP),研究了发泡过程中工艺条件、配方对最终产物结构和性能的影响.获得了性能较优异的发泡聚丙烯的发泡工艺条件及配方:上下横板温度180℃-190℃,模压压力7.5MPa-10.0MPa;发泡剂AC用量1.0%-1.5%,交联剂DCP用量0.1%-0.3%,成核剂SiO2用量0.15%-0.25%.%In this study, the chemical cross-linked method was used to foam Polypropylene (PP) by one-step process of mould pressing. We studied the effects of technologcial conditions and formulation on the structure and properties during the foaming precess. Then we got the better technologcial conditions and formulation, which can foam the polypropylene with excellent properties. The temperature of the upper and bottom hot plate is 180℃ 190℃; the mould pressure is 7.5MPa - 10. 0MPa; The amount of foam agent (AC), cross-linker (DCP) and nucleating agent (SiO2) is 1.0% - 1.5%, 0. 1% -0. 3% and 0. 15% -0. 25% respectively.

  4. Clinical Observation of Two Kinds of Suture of the Perineal Suture%两种缝线两种会阴缝合的临床观察

    Institute of Scientific and Technical Information of China (English)

    王建华

    2014-01-01

    Objective To investigate the clinical ef ect of legitimate perineal suture. Methods 200 cases of vaginal delivery. Were randomly divided into observation group and control group two groups, each of 100 cases. The two group contains perineal incision 50 people left and perineal tear 50 nature. 2% lidocaine local infiltration anesthesia. The observation group 2-0 catgut suture, perineal suture. The control with 4 silk interrupted perineal suture. Results The two groups in the post natal maternal incision pain, 72 hours of activity level dif erences were statistical y significant ( <0.05). The observation group 2-0 catgut, continuous suture applies to the perineum wound (including side cut and split wound).Conclusion Tthe observation group using continuous suture in postpartum postpartum incision pain and activity limitation is superior to the control group of the suture.%目的探讨会阴缝合法的临床应用效果。方法选择阴道分娩产妇200例。随机分成观察组和对照组两组,各100例。两组均包含会阴左侧切口50例及会阴自然撕裂口50例。2%的利多卡因局部浸润麻醉。观察组2-0医用羊肠线,连续缝合法行会阴缝合术。对照用4号丝线间断会阴缝合法。结果两组在产后切口疼痛,产妇72h活动程度方面差异均有统计学意义(均<0.05)。采用观察组2-0医用羊肠线,连续缝合法适用于会阴伤口(包括侧切及裂开伤口)。结论观察组采用连续缝合法在产后切口疼痛及产后活动受限方面明显优于对照组的间断缝合法。

  5. Phenolic stabilisers extraction constants of polypropylene geotextiles determination in alkali medium

    OpenAIRE

    Farcas, Fabienne; Fayolle, Bruno; Azzouz, Mériam; Richaud, Emmanuel

    2012-01-01

    The use of geotextiles made of polypropylene (PP) in civil engineering such as tunnel requieres adequates control over their durability, and this characteristic remains poorly known due to their inaccessibility. Considering concrete environment ageing conditions (alkali medium i.e. pH = 9 to 13), the aim of this study is to complete a non-empirical kinetic model for polypropylene ageing by the determination of the extraction parameters a frequently used phenolic process stabilisers: Irganox 1...

  6. Mesoproterozoic suturing of Archean crustal blocks in western peninsular India: Implications for India-Madagascar correlations

    Science.gov (United States)

    Ishwar-Kumar, C.; Santosh, M.; Wilde, S. A.; Tsunogae, T.; Itaya, T.; Windley, B. F.; Sajeev, K.

    2016-10-01

    The Kumta and Mercara suture zones welding together Archean crustal blocks in western peninsular India offer critical insights into Precambrian continental juxtapositions and the crustal evolution of eastern Gondwana. Here we present the results from an integrated study of the structure, geology, petrology, mineral chemistry, metamorphic P-T conditions, zircon U-Pb ages and Lu-Hf isotopes of metasedimentary rocks from the two sutures. The dominant rocks in the Kumta suture are greenschist- to amphibolite-facies quartz-phengite schist, garnet-biotite schist, chlorite schist, fuchsite schist and marble. The textural relations, mineral chemistry and thermodynamic modelling of garnet-biotite schist from the Kumta suture indicate peak metamorphic P-T conditions of ca. 11 kbar at 790 °C, with detrital SHRIMP U-Pb zircon ages ranging from 3420 to 2547 Ma, εHf (t) values from - 9.2 to 5.6, and TDMc model ages from 3747 to 2792 Ma. The K-Ar age of phengite from quartz-phengite schist is ca. 1326 Ma and that of biotite from garnet-biotite schist is ca. 1385 Ma, which are interpreted to broadly constrain the timing of metamorphism related to the suturing event. The Mercara suture contains amphibolite- to granulite-facies mylonitic quartzo-feldspathic gneiss, garnet-kyanite-sillimanite gneiss, garnet-biotite-kyanite-gedrite-cordierite gneiss, garnet-biotite-hornblende gneiss, calc-silicate granulite and metagabbro. The textural relations, mineral chemistry and thermodynamic modelling of garnet-biotite-kyanite-gedrite-cordierite gneiss from the Mercara suture indicate peak metamorphic P-T conditions of ca. 13 kbar at 825 °C, followed by isothermal decompression and cooling. For pelitic gneisses from the Mercara suture, LA-ICP-MS U-Pb zircon ages vary from 3249 to 3045 Ma, εHf (t) values range from - 18.9 to 4.2, and TDMc model ages vary from 4094 to 3314 Ma. The lower intercept age of detrital zircons in the pelitic gneisses from the Mercara suture ranges from 1464 to 1106

  7. 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

    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.

  8. 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.

  9. STUDIES ON THE PORE FORMATION MECHANISM OF β-CRYSTALLINE POLYPROPYLENE UNDER STRETCHING

    Institute of Scientific and Technical Information of China (English)

    Shao-feng Ran; Mao Xu

    2004-01-01

    The pore formation mechanism of β-crystalline polypropylene under stretching was investigated. The porosity of the samples increases rapidly with stretching, having a maximum at draw ratios around 2 and then decreases monotonically.An abrupt formation process of initial micropores at very low draw ratios was evidenced by in situ SAXS measurements. At the same time the phase transition from β-crystal to a-crystal proceeds slowly in the whole deformation process up to large draw ratios around 5. Comparative studies of a- and β-crystalline polypropylene samples before stretching indicate that in addition to difference in crystal forms the a- and β-crystalline polypropylene samples exhibit quite different morphological features. There are a lot of interfaces in β-crystalline polypropylene samples, which may have a lower density value and can be easily etched by argon ions and penetrated by small molecules. It was concluded from these experimental facts that the pore formation and crystal transition are two independent phenomena during the deformation of β-crystalline polypropylene samples, and phase transition from β-crystal to a-crystal could hardly be the origin of pore formation. A defect initiation mechanism was proposed to understand the pore formation behavior of β-crystalline polypropylenes.

  10. Supercritical CO2 Foaming of Radiation Cross-Linked Isotactic Polypropylene in the Presence of TAIC

    Directory of Open Access Journals (Sweden)

    Chen-Guang Yang

    2016-12-01

    Full Text Available Since the maximum foaming temperature window is only about 4 °C for supercritical CO2 (scCO2 foaming of pristine polypropylene, it is important to raise the melt strength of polypropylene in order to more easily achieve scCO2 foaming. In this work, radiation cross-linked isotactic polypropylene, assisted by the addition of a polyfunctional monomer (triallylisocyanurate, TAIC, was employed in the scCO2 foaming process in order to understand the benefits of radiation cross-linking. Due to significantly enhanced melt strength and the decreased degree of crystallinity caused by cross-linking, the scCO2 foaming behavior of polypropylene was dramatically changed. The cell size distribution, cell diameter, cell density, volume expansion ratio, and foaming rate of radiation-cross-linked polypropylene under different foaming conditions were analyzed and compared. It was found that radiation cross-linking favors the foamability and formation of well-defined cell structures. The optimal absorbed dose with the addition of 2 wt % TAIC was 30 kGy. Additionally, the foaming temperature window was expanded to about 8 °C, making the handling of scCO2 foaming of isotactic polypropylene much easier.

  11. Nano-Mechanical Studies on Polyglactin Sutures Subjected to In Vitro Hydrolytic and Enzymatic Degradation.

    Science.gov (United States)

    Sun, Leming; Wanasekara, Nandula; Chalivendra, Vijaya; Calvert, Paul

    2015-01-01

    An experimental investigation on the effects of in vitro hydrolytic and enzymatic degradation on mechanical properties of polyglactin 910 monofilament sutures was performed by conducting nanoindentation studies using an atomic force microscope (AFM). For hydrolytic degradation, the sutures were incubated in phosphate buffered saline (PBS) solution at three different pH conditions, 5, 7.4, and 10. For enzymatic degradation, esterase was employed at pH condition of 7.4. The property of the sutures changed with time at different conditions were investigated by nanoindentation, tensile test experiments, image analysis using both of scanning electron microscopy (SEM) and AFM, and also Fourier transform infrared spectroscopy (FTIR). The effects of degradation on gradation of Young's modulus values across the cross section of the sutures were studied by doing progressive nanoindentation from center to surface. FTIR studies revealed the formation of new hydroxyl bonds due to both hydrolytic and enzymatic degradations. Nanoindentation results indicated that the degradation does not cause a gradient of Young's modulus of the polyglactin 910 monofilament sutures across the cross section from center to surface at different degradation times for both hydrolytic and enzymatic degradations. However, in general, the Young's modulus of all samples was decreased over 4 weeks of degradation. The microscopic evaluation of the samples also showed both qualitative changes in surface morphology and quantitative changes in surface roughness on the surface of degraded sutures. This study provided a deep understanding of the polyglactin sutures subjected to in vitro hydrolytic and enzymatic degradation, and also opened a new avenue to study the biomaterials at nano-scale.

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

    Directory of Open Access Journals (Sweden)

    Gazivoda Dragan

    2015-01-01

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

  13. A novel scandium fluoride, [C2N2H10]0.5[ScF4], with an unprecedented tungsten bronze-related layer structure.

    Science.gov (United States)

    Stephens, Nicholas F; Slawin, Alexandra M Z; Lightfoot, Philip

    2004-03-07

    [C(2)N(2)H(10)](0.5)[ScF(4)] exhibits isolated anionic layers of corner-linked ScF(6) octahedra enclosing 3-, 4-, 5- and 6-membered rings, with features reminiscent of both hexagonal and tetragonal tungsten bronze-type structures.

  14. Biomechanical Comparison of Parallel and Crossed Suture Repair for Longitudinal Meniscus Tears

    Science.gov (United States)

    Milchteim, Charles; Branch, Eric A.; Maughon, Ty; Hughey, Jay; Anz, Adam W.

    2016-01-01

    Background: Longitudinal meniscus tears are commonly encountered in clinical practice. Meniscus repair devices have been previously tested and presented; however, prior studies have not evaluated repair construct designs head to head. This study compared a new-generation meniscus repair device, SpeedCinch, with a similar established device, Fast-Fix 360, and a parallel repair construct to a crossed construct. Both devices utilize self-adjusting No. 2-0 ultra–high molecular weight polyethylene (UHMWPE) and 2 polyether ether ketone (PEEK) anchors. Hypothesis: Crossed suture repair constructs have higher failure loads and stiffness compared with simple parallel constructs. The newer repair device would exhibit similar performance to an established device. Study Design: Controlled laboratory study. Methods: Sutures were placed in an open fashion into the body and posterior horn regions of the medial and lateral menisci in 16 cadaveric knees. Evaluation of 2 repair devices and 2 repair constructs created 4 groups: 2 parallel vertical sutures created with the Fast-Fix 360 (2PFF), 2 crossed vertical sutures created with the Fast-Fix 360 (2XFF), 2 parallel vertical sutures created with the SpeedCinch (2PSC), and 2 crossed vertical sutures created with the SpeedCinch (2XSC). After open placement of the repair construct, each meniscus was explanted and tested to failure on a uniaxial material testing machine. All data were checked for normality of distribution, and 1-way analysis of variance by ranks was chosen to evaluate for statistical significance of maximum failure load and stiffness between groups. Statistical significance was defined as P < .05. Results: The mean maximum failure loads ± 95% CI (range) were 89.6 ± 16.3 N (125.7-47.8 N) (2PFF), 72.1 ± 11.7 N (103.4-47.6 N) (2XFF), 71.9 ± 15.5 N (109.4-41.3 N) (2PSC), and 79.5 ± 25.4 N (119.1-30.9 N) (2XSC). Interconstruct comparison revealed no statistical difference between all 4 constructs regarding maximum

  15. Prediction of rapid maxillary expansion by assessing the maturation of the midpalatal suture on cone beam CT

    Directory of Open Access Journals (Sweden)

    Fernanda Angelieri

    Full Text Available ABSTRACT Rapid maxillary expansion (RME primarily involves the mechanical opening of the midpalatal suture of the maxillary and palatine bones. The fusion of the midpalatal suture determines the failure of RME, a common event in late adolescents and young adults. Recently, the assessment of the maturation of midpalatal suture as viewed using cone beam computed tomography (CBCT has been introduced. Five maturational stages of the midpalatal suture have been presented: Stage A = straight high-density sutural line, with no or little interdigitation; Stage B = scalloped appearance of the high-density sutural line; Stage C = two parallel, scalloped, high-density lines that lie close to each other, separated in some areas by small low-density spaces; Stage D = fusion of the palatine bone where no evidence of a suture is present; and Stage E = complete fusion that extends also anteriorly in the maxilla. At Stage C, less skeletal response would be expected than at Stages A and B, as there are many bony bridges along the suture. For patients at Stages D and E, surgically assisted RME would be necessary, as the fusion of the midpalatal suture already has occurred either partially or totally. This diagnostic method can be used to estimate the prognosis of the RME, mainly for late adolescents and young adults for whom this procedure is unpredictable clinically.

  16. Prediction of rapid maxillary expansion by assessing the maturation of the midpalatal suture on cone beam CT

    Science.gov (United States)

    Angelieri, Fernanda; Franchi, Lorenzo; Cevidanes, Lucia H. S.; Bueno-Silva, Bruno; McNamara, James A.

    2016-01-01

    ABSTRACT Rapid maxillary expansion (RME) primarily involves the mechanical opening of the midpalatal suture of the maxillary and palatine bones. The fusion of the midpalatal suture determines the failure of RME, a common event in late adolescents and young adults. Recently, the assessment of the maturation of midpalatal suture as viewed using cone beam computed tomography (CBCT) has been introduced. Five maturational stages of the midpalatal suture have been presented: Stage A = straight high-density sutural line, with no or little interdigitation; Stage B = scalloped appearance of the high-density sutural line; Stage C = two parallel, scalloped, high-density lines that lie close to each other, separated in some areas by small low-density spaces; Stage D = fusion of the palatine bone where no evidence of a suture is present; and Stage E = complete fusion that extends also anteriorly in the maxilla. At Stage C, less skeletal response would be expected than at Stages A and B, as there are many bony bridges along the suture. For patients at Stages D and E, surgically assisted RME would be necessary, as the fusion of the midpalatal suture already has occurred either partially or totally. This diagnostic method can be used to estimate the prognosis of the RME, mainly for late adolescents and young adults for whom this procedure is unpredictable clinically. PMID:28125147

  17. 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.

  18. 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.

  19. 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.

  20. Mitral valve repair: is there still a place for suture annuloplasty?

    Science.gov (United States)

    Fundarò, Pino; Tartara, Paolo M; Villa, Emmanuel; Fratto, Pasquale; Campisi, Salvatore; Vitali, Ettore O

    2007-08-01

    Prosthetic ring annuloplasty is considered the gold standard technique for mitral valve repair, but it has been associated with some drawbacks. Suture annuloplasty is less expensive and may have some physiopathologic advantages. We reviewed the literature to assess clinical results of mitral suture annuloplasty. Thirteen series, each reporting more than 50 patients and published in the last 10 years, were included in the analysis. They comprised 1,648 patients with cumulative follow-up of 5,607 patient-years. Our review suggests that suture annuloplasty is a safe procedure, but a trend toward recurrence of annular dilatation with time was reported. In selected cases, suture annuloplasty is effective, and its mid-term clinical results are encouraging and compare well with those of prosthetic ring repair series. The quality of the results varies according to the particular annuloplasty technique used and to the mitral valve pathology treated. Recent technical modifications have been found to decrease the incidence of repair failure and promise to improve the reproducibility of the procedure. Further investigations are warranted to better assess the long-term results of suture annuloplasty, and to determine whether its theoretical functional advantages translate into a real clinical benefit.

  1. Long-term active antimicrobial coatings for surgical sutures based on silver nanoparticles and hyperbranched polylysine.

    Science.gov (United States)

    Ho, Chau Hon; Odermatt, Erich K; Berndt, Ingo; Tiller, Joerg C

    2013-01-01

    The goal of this study was to develop a long-term active antimicrobial coating for surgical sutures. To this end, two water-insoluble polymeric nanocontainers based on hyperbranched polylysine (HPL), hydrophobically modified by either using glycidyl hexadecyl ether, or a mixture of stearoyl/palmitoyl chloride, were synthesized. Highly stabilized silver nanoparticles (AgNPs, 2-5 nm in size) were generated by dissolving silver nitrate in the modified HPL solutions in toluene followed by reduction with L-ascorbic acid. Poly(glycolic acid)-based surgical sutures were dip-coated with the two different polymeric silver nanocomposites. The coated sutures showed high efficacies of more than 99.5% reduction of adhesion of living Staphylococcus aureus cells onto the surface compared to the uncoated specimen. Silver release experiments were performed on the HPL-AgNP modified sutures by washing them in phosphate buffered saline for a period of 30 days. These coatings showed a constant release of silver ions over more than 30 days. After this period of washing, the sutures retained their high efficacies against bacterial adhesion. Cytotoxicity tests using L929 mouse fibroblast cells showed that the materials are basically non-cytotoxic.

  2. 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 μm 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.

  3. Efeitos cardiovasculares e midriáticos da fenilefrina tópica a 2,5 e a 10,0% em voluntários sadios

    OpenAIRE

    Diniz Filho,Alberto; Frasson,Maria; Mérula,Rafael Vidal; Morais,Patrick Reis; Cronemberger, Sebastião

    2007-01-01

    OBJETIVO: Comparar os efeitos cardiovasculares e midriáticos da fenilefrina tópica nas concentrações de 2,5 e 10,0%. MÉTODOS: Ensaio clínico do tipo caso controle, randomizado, com auto-emparelhamento. Foram monitoradas a freqüência cardíaca (FC), a pressão arterial (PA) e a midríase em voluntários sadios, com idade entre 18 e 45 anos, após a instilação da fenilefrina a 2,5 e a 10,0% em duas ocasiões diferentes. RESULTADOS: A amostra foi constituída de 28 voluntários, sendo 17 do sexo masculi...

  4. Industrial Catalysis%Effects of beta nucleating agent on mechanical properties of polypropylene

    Institute of Scientific and Technical Information of China (English)

    马丽; 王文燕; 张怀志; 侯雅丽

    2016-01-01

    通过在抗冲聚丙烯基础树脂中添加自主研制的酰胺型高效β成核剂,在升高聚丙烯耐热温度的同时有效提高聚丙烯树脂EPS30 R的冲击强度,研究酰胺型β成核剂PA-01、TMB-5和FB-1添加量对聚丙烯树脂EPS30 R力学性能的影响,通过微观形态分析增韧的内在原因,并考察成核剂对聚丙烯树脂EPS30 R的成核效果。结果表明,添加β成核剂后,聚丙烯的力学性能明显改善,且β成核剂诱导聚丙烯的成核效果较好。%By adding self-developed high-efficiency amide β nucleating agents into impact polypropylene base resin,the heat resistance temperature of polypropylene was improved and meanwhile the impact strength of polypropylene resin EPS30R was also effectively improved. The effects of the amounts of amideβnucleating agents PA-01 ,TMB-5 and FB-1 on the mechanical properties of polypropylene resin EPS30 R were researched by microscopic morphological analysis of toughening internal causes. The influence of nucleating agent on nucleating effect of polypropylene resin EPS30R was also investigated. The results showed that after adding beta nucleating agent,the mechanical properties of polypropylene were improved obviously,and nucleating effect of polypropylene induced by beta nucleating agent was better.

  5. Can we save a follow up appointment by leaving nylon sutures under plaster for 6 weeks

    Directory of Open Access Journals (Sweden)

    Randeep Aujla

    2010-02-01

    Full Text Available Randeep Aujla, Abhinav Gulihar, Andrew Chandraraj, Graham TaylorOrthopaedic Department, Glenfield Hospital, Groby Road, Leicester, EnglandBackground: The purpose of this study was to highlight the potential resource saving method of leaving nylon sutures under plaster for 6 weeks after forefoot surgery. Methods: We gathered patient data from 72 cases of forefoot surgery over a 5-year period and analyzed the complications encountered. Only patients who required at least 6 weeks of plaster were included.Results: There were two cases of wound infection and one of flap necrosis. The infection rates are comparable to previous studies into forefoot surgery infection rates. There was no difficulty in removing the sutures and scarring was not noted to be a problem.Conclusions: Financial, convenience and time benefits could be obtained if this technique was in common practice.Keywords: elective forefoot surgery, wound infections, wound complications, nylon sutures

  6. Diaphragmatic suture with tubular stomach to prevent early delayed gastric emptying after esophagectomy

    Institute of Scientific and Technical Information of China (English)

    Chao Sun; Weiping Shi; Yusheng Shu; Hongcan Shi; Shichun Lu; Kang Wang

    2015-01-01

    Objective The objective of this study was to evaluate the clinical ef icacy of a diaphragmatic suture with tubular stomach to prevent delayed gastric emptying (DGE) after esophagectomy through the cervico-tho-racoabdominal approach. Methods A total of 980 patients with esophageal cancer undergoing esophagectomy through the cer-vico-thoracoabdominal approach were retrospectively included in this study and divided into two groups. Al patients underwent tubular stomach creation (group A; n = 530) or a diaphragmatic suture and tubular stomach creation (group B; n = 450). The incidence of early DGE was observed. Results The incidence of early DGE in group A was significantly higher than that in group B (P Conclusion This observation study suggests that the use of a diaphragmatic suture with tubular stomach through the cervico-thoracoabdominal approach can decrease the incidence of early DGE after esopha-gectomy.

  7. 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;

    2012-01-01

    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......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...

  8. 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.

  9. Allergy to Prolene Sutures in a Dural Graft for Chiari Decompression

    Directory of Open Access Journals (Sweden)

    Iahn Cajigas

    2015-01-01

    Full Text Available Allergy to Prolene suture is exceedingly rare with only 5 cases reported in the literature. There have been no such cases associated with neurosurgical procedures. Diagnosis is nearly always delayed in spite of persistent symptomatology. A 27-year-old girl with suspected Ehlers-Danlos, connective tissue disorder, underwent posterior fossa decompression for Chiari Type 1 malformation. One year later, the patient presented with urticarial rash from the neck to chest. Cerebrospinal fluid and blood testing, magnetic resonance imaging, and intraoperative exploration did not suggest allergic reaction. Eventually skin testing proved specific Prolene allergy. After suture material was removed, the patient no longer complained of pruritus or rash. This single case highlights the important entity of allergic reaction to suture material, namely, Prolene, which can present in a delayed basis. Symptomatology can be vague but has typical allergic characteristics. Multidisciplinary approach is helpful with confirmatory skin testing as a vital part of the workup.

  10. Entrapment of Common Peroneal Nerve by Surgical Suture following Distal Biceps Femoris Tendon Repair

    Directory of Open Access Journals (Sweden)

    Aki Fukuda

    2016-01-01

    Full Text Available We describe entrapment of the common peroneal nerve by a suture after surgical repair of the distal biceps femoris tendon. Complete rupture of the distal biceps femoris tendon of a 16-year-old male athlete was surgically repaired. Postoperative common peroneal nerve palsy was evident, but conservative treatment did not cause any neurological improvement. Reexploration revealed that the common peroneal nerve was entrapped by the surgical suture. Complete removal of the suture and external neurolysis significantly improved the palsy. The common peroneal nerve is prone to damage as a result of its close proximity to the biceps femoris tendon and it should be identified during surgical repair of a ruptured distal biceps femoris tendon.

  11. Novel high efficient coatings for anti-microbial surgical sutures using chlorhexidine in fatty acid slow-release carrier systems.

    Directory of Open Access Journals (Sweden)

    Andreas Obermeier

    Full Text Available 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.

  12. Upper lid crease approach for margin rotation in trachomatous cicatricial entropion without external sutures

    Directory of Open Access Journals (Sweden)

    Antonio Augusto Velasco e Cruz

    2015-12-01

    Full Text Available ABSTRACT Purpose: To describe the use of a lid crease incision for upper eyelid margin rotation in cicatricial entropion combining internal traction on the anterior lamella, tarsotomy, and tarsal overlap without external sutures. Methods: Surgical description: The main steps of the procedure consisted of exposure of the entire tarsal plate up to the eyelashes followed by tarsotomy through the conjunctiva. A double-armed 6.0 polyglactin suture was then passed through the distal tarsal fragment to the marginal section of the orbicularis oculi muscle. As the sutures were tied, the distal tarsus advanced over the marginal section, and traction was exerted on the marginal strip of the orbicularis muscle. There were no bolsters or external knots. The pretarsal skin-muscle flap was closed with a 6.0 plain gut suture. Results: We used this procedure at a tertiary hospital in Saudi Arabia from 2013 to 2014. Sixty upper lids of 40 patients (23 women and 17 men were operated on, with an age range of 44-99 years [mean ± standard deviation (SD = 70.9 ± 13.01 years]. Bilateral surgery was performed on 21 patients. Follow-up ranged from 1 to 12 months (mean 3.0 ± 2.71 months. Forty percent of the patients (24 lids had more than 3 months' follow-up. The postoperative lid margin position was good in all cases. Trichiasis (two lashes was observed in only one patient with unilateral entropion on the medial aspect of the operated lid. Conclusions: The upper lid margin can be effectively rotated through a lid crease incision with internal sutures. The technique combines the main mechanisms of the Wies and Trabut approaches and avoids the use of bolsters or external sutures, which require a second consultation to be removed. Some other lid problems, such as ptosis, retraction, or dermatochalasis, can be concomitantly addressed during the procedure.

  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. Atomic force microscopy study of biaxially oriented polypropylene films

    Science.gov (United States)

    Nie, H.-Y.; Walzak, M. J.; McIntyre, N. S.

    2004-08-01

    Atomic force microscopy (AFM) uses a very sharp pointed mechanical probe to collect real-space morphological information of solid surfaces. AFM was used in this study to image the surface morphology of a biaxially oriented polypropylene film. The polymer film is characterized by a nanometer-scale, fiberlike network structure, which reflects the drawing process used during the fabrication of the film. AFM was used to study polymer-surface treatment to improve wettability by exposing the polymer to ozone with or without ultraviolet (UV) irradiation. Surface-morphology changes observed by AFM are the result of the surface oxidation induced by the treatment. Due to the topographic features of the polymer film, the fiberlike structure has been used to check the performance of the AFM tip. An AFM image is a mixture of the surface morphology and the shape of the AFM tip. Therefore, it is important to check the performance of a tip to ensure that the AFM image collected reflects the true surface features of the sample, rather than contamination on the AFM tip.

  15. Electromagnetic interference shielding effectiveness of polypropylene/conducting fiber composites

    Science.gov (United States)

    Lee, Pyoung-Chan; Kim, Bo-Ram; Jeoung, Sun Kyoung; Kim, Yeung Keun

    2016-03-01

    Electromagnetic released from the automotive electronic parts is harmful to human body. Electromagnetic interference (EMT) shielding refers to the reflection and/or adsorption of electromagnetic radiation by a material, which thereby acts as a shield against the penetration of the radiation through the shield. Polypropylene (PP)/conductive micro fiber composites containing various fiber contents and fiber length were injection-molded. The effect of fiber content and length on electrical properties of the composites was studied by electrical resistivity and EMT shielding measurements. The through-plane electrical conductivity and dielectric permittivity were obtained by measuring dielectric properties. The EMT shielding effectiveness (SE) was investigated by using S-parameter in the range of 100 ~ 1500 MHz. Reflection, absorption and multiple-reflection are the EMT attenuation mechanisms. From the measurement of S-Parameters, the absorption coefficient, reflection coefficient, and the shielding efficiency of the materials were calculated. The EMT SE of PP/conducing fiber composites is 40 dB over a wide frequency range up to 1.5 GHz, which is higher than that of PP/talc composite used automotive parts, viz. 0 dB.

  16. Formation and antifouling properties of amphiphilic coatings on polypropylene fibers.

    Science.gov (United States)

    Goli, Kiran K; Rojas, Orlando J; Genzer, Jan

    2012-11-12

    We describe the formation of amphiphilic polymeric assemblies via a three-step functionalization process applied to polypropylene (PP) nonwovens and to reference hydrophobic self-assembled n-octadecyltrichlorosilane (ODTS) monolayer surfaces. In the first step, denatured proteins (lysozyme or fibrinogen) are adsorbed onto the hydrophobic PP or the ODTS surfaces, followed by cross-linking with glutaraldehyde in the presence of sodium borohydride (NaBH(4)). The hydroxyl and amine functional groups of the proteins permit the attachment of initiator molecules, from which poly (2-hydroxyethyl methacrylate) (PHEMA) polymer grafts are grown directly through "grafting from" atom transfer radical polymerization. The terminal hydroxyls of HEMA's pendent groups are modified with fluorinating moieties of different chain lengths, resulting in amphiphilic brushes. A palette of analytical tools, including ellipsometry, contact angle goniometry, Fourier transform infrared spectroscopy in the attenuated total reflection mode, and X-ray photoelectron spectroscopy is employed to determine the changes in physicochemical properties of the functionalized surfaces after each modification step. Antifouling properties of the resultant amphiphilic coatings on PP are analyzed by following the adsorption of fluorescein isothiocyanate-labeled bovine serum albumin as a model fouling protein. Our results suggest that amphiphilic coatings suppress significantly adsorption of proteins as compared with PP fibers or PP surfaces coated with PHEMA brushes. The type of fluorinated chain grafted to PHEMA allows modulation of the surface composition of the topmost layer of the amphiphilic coating and its antifouling capability.

  17. Functional behaviour of polypropylene/ZnO soluble starch nanocomposites

    Science.gov (United States)

    Chandramouleeswaran, Subramani; Mhaske, S. T.; Kathe, A. A.; Varadarajan, P. V.; Prasad, Virendra; Vigneshwaran, Nadanathangam

    2007-09-01

    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.

  18. Benzothiazole sulfide compatibilized polypropylene/halloysite nanotubes composites

    Energy Technology Data Exchange (ETDEWEB)

    Liu Mingxian [Department of Polymer Materials and Engineering, South China University of Technology, Guangzhou 510640 (China); Guo Baochun, E-mail: psbcguo@scut.edu.cn [Department of Polymer Materials and Engineering, South China University of Technology, Guangzhou 510640 (China); Lei Yanda; Du Mingliang; Jia Demin [Department of Polymer Materials and Engineering, South China University of Technology, Guangzhou 510640 (China)

    2009-02-15

    Clay-philic benzothiazole sulfide, capable of donating electrons, is grafted onto polypropylene (PP) backbones when N-cyclohexyl-2-benzothiazole sulfonamide (CBS), a commonly used accelerator in the tire industry, is included in the processing of PP/halloysite nanotubes (HNTs) composites. CBS decomposes at elevated temperature and yields benzothiazole sulfide radicals, which react with the PP polymeric free radicals generated during the processing of the composites. On the other hand, the benzothiazole group of CBS is reactive to HNTs via electron transferring. The compatibilization between HNTs and PP is thus realized via interfacial grafting and electron transferring mechanism. The interfacial interactions in the compatibilized systems were fully characterized. Compared with the control sample, the dispersion of HNTs and the interfacial bonding are enhanced substantially in the compatibilized composites. The significantly improved mechanical properties and thermal properties of benzothiazole sulfide compatibilized PP/HNTs composites are correlated to the enhanced interfacial property. The present work demonstrates a novel interfacial design via interfacial grafting/electron transferring for the compatibilization of PP/clay composites.

  19. Effect of Nanosilica Filled Polyurethane Composite Coating on Polypropylene Substrate

    Directory of Open Access Journals (Sweden)

    Yern Chee Ching

    2013-01-01

    Full Text Available Acrylic based polyurethane (PU coatings with various amounts of nanosilica contents were prepared using solution casting method. The nanosilica (SiO2 particles used are around 16 nm in diameter. The friction and wear test was conducted using the reciprocating wear testing machine. The tests were performed at rotary speed of 100 rpm and 200 rpm with load of 0.1 kg to 0.4 kg under 1 N interval. The effect of the PU/nano-SiO2 composite coating on friction and wear behavior of polypropylene substrate was investigated and compared. The worn surface of coating film layer after testing was investigated by using an optical microscope. The introduction of PU/nanosilica composite coating containing 3 wt% of nano-SiO2 content gives the lowest friction coefficient and wear rate to PP substrate. Both the friction and wear rate of PP substrate coated with >3 wt% of nano-SiO2 filled PU coating would increase with the increasing of applied load and sliding time.

  20. 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 γ-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.

  1. A NEW SYNERGIST FOR INTUMESCENT FLAME RETARDANT POLYPROPYLENE

    Institute of Scientific and Technical Information of China (English)

    Qiang Wu; Bao-jun Qu

    2002-01-01

    The synergistic effects of silicotungstic acid (SiW12) as a catalyst in the phosphorus-nitrogen compounds AM-based intumescent flame-retardant (IFR) polypropylene (PP) were studied using the limiting oxygen index (LOI), the UL-94test, thermogravimetric analysis (TGA), real time Fourier transform infrared (FTIR), laser Raman spectroscopy (LRS). TheLOI data show that SiW12 added to PP/IFR systems has a synergistic FR effect with an IFR additive named AM. The TGAdata show that SiW12 apparently increases the thermal stability of the PP/IFR systems at high temperature (T > 500 ℃). TheFTIR results provide the positive evidence that IFR can improve the thermal stability of PP and SiW12 can induce a higherrate of formation of phosphoric acid and its derivatives. The LRS measurements provide useful information on thecarbonaceous microstructures. In short, a suitable amount of SiW12 (1.5 wt%) exertssynergistic effects with the IFR byincreasing the LOI value and the thermal stability at high temperature and promoting the formation of charred structures onthe burning PP surface.

  2. Mapping physicochemical surface modifications of flame-treated polypropylene

    Directory of Open Access Journals (Sweden)

    S. Farris

    2014-04-01

    Full Text Available The aim of this work was to investigate how the surface morphology of polypropylene (PP is influenced by the surface activation mediated by a flame obtained using a mixture of air and propane under fuel-lean (equivalence ratio φ = 0.98 conditions. Morphological changes observed on flamed samples with smooth (S, medium (M, and high (H degree of surface roughness were attributed to the combined effect of a chemical mechanism (agglomeration and ordering of partially oxidized intermediate-molecular-weight material with a physical mechanism (flattening of the original roughness by the flame’s high temperature. After two treatments, the different behavior of the samples in terms of wettability was totally reset, which made an impressive surface energy of ~43 mJ•m–2 possible, which is typical of more hydrophilic polymers (e.g., polyethylene terephthalate – PET. In particular, the polar component was increased from 1.21, 0.08, and 0.32 mJ•m–2 (untreated samples to 10.95, 11.20, and 11.17 mJ•m–2 for the flamed samples S, M, and H, respectively, an increase attributed to the insertion of polar functional groups (hydroxyl and carbonyl on the C–C backbone, as demonstrated by the X-ray photoelectron spectroscopy results.

  3. 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 MΩ and a resonance frequency of 800 Hz, a maximum output power of 120 μW, 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.

  4. 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 ṡ 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 MΩ and a resonance frequency of 800 Hz, a maximum output power of 120 μW, 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.

  5. Polypropylenes foam consisting of thermally expandable microcapsule as blowing agent

    Science.gov (United States)

    Jeoung, Sun Kyung; Hwang, Ye Jin; Lee, Hyun Wook; Kwak, Sung Bok; Han, In-Soo; Ha, Jin Uk

    2016-03-01

    The structure of thermally expandable microcapsule (TEMs) is consisted of a thermoplastic shell which is filled with liquid hydrocarbon at core. The shell of TEMs becomes soft when the temperature is higher than boiling temperature of liquid hydrocarbon. The shell of TEMs is expanded under the high temperature because the inner pressure of TEMs is increased by vaporization of hydrocarbon core. Therefore, the TEMs are applicable for blowing agents and light weight fillers. In this research, we fabricated the polypropylene (PP) foam by using the TEMs and chemical blowing agents and compared to their physical properties. The density of the specimen was decreased when the contents of chemical blowing agents and TEMs were increased. In addition, the mechanical properties (i.e. tensile strength and impact strength) of specimens were deteriorated with increasing amount of chemical blowing agents and TEMs. However, PP foam produced with TEMs showed higher impact strength than the one with the chemical blowing agent. In order to clarify the dependence of impact strength of PP foam as the blowing agent, the morphology difference of the PP foams was investigated. Expanding properties of PP foams produced with TEMs was changed with TEMs content of PP foams. Processing conditions also influenced the mechanical properties of PP foam containing TEMs.

  6. Energy harvesting from vibration with cross-linked polypropylene piezoelectrets

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaoqing [Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology & School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Institute for Telecommunications Technology, Merckstrasse 25, 64283 Darmstadt (Germany); Wu, Liming [Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology & School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Sessler, Gerhard M., E-mail: g.sessler@nt.tu-darmstadt.de [Institute for Telecommunications Technology, Merckstrasse 25, 64283 Darmstadt (Germany)

    2015-07-15

    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 d{sub 33} coefficients up to 650 pC/N at 200 Hz are achieved. The figure of merit (FOM, d{sub 33} ⋅ g{sub 33}) for a more typical d{sub 33} value of 400 pC/N is about 11.2 GPa{sup −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 MΩ and a resonance frequency of 800 Hz, a maximum output power of 120 μW, 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 cm{sup 2} 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.

  7. 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.

  8. Improved Mechanical Properties of Compatibilized Polypropylene/Polyamide-12 Blends

    Directory of Open Access Journals (Sweden)

    Nora Aranburu

    2015-01-01

    Full Text Available Compatibilized blends of polypropylene (PP and polyamide-12 (PA12 as a second component were obtained by direct injection molding having first added 20% maleic anhydride-modified copolymer (PP-g-MA to the PP, which produced partially grafted PP (gPP. A nucleating effect of the PA12 took place on the cooling crystallization of the gPP, and a second crystallization peak of the gPP appeared in the PA12-rich blends, indicating changes in the crystalline morphology. There was a slight drop in the PA12 crystallinity of the compatible blends, whereas the crystallinity of the gPP increased significantly in the PA12-rich blends. The overall reduction in the dispersed phase particle size together with the clear increase in ductility when gPP was used instead of PP proved that compatibilization occurred. Young’s modulus of the blends showed synergistic behavior. This is proposed to be both due to a change in the crystalline morphology of the blends on the one hand and, on the other, in the PA12-rich blends, to the clear increase in the crystallinity of the gPP phase, which may, in turn, have been responsible for the increase in its continuity and its contribution to the modulus.

  9. Isotactic polypropylene carbon nanotube composites -- crystallization and ordering behavior

    Science.gov (United States)

    Georgiev, Georgi; Judith, Robert; Gombos, Erin; McIntyre, Michael; Schoen, Scott; Cebe, Peggy; Mattera, Michael

    2010-03-01

    The field of Polymer Nanocomposites (PNCs) is growing steadily in recent years. We use carbon nanotubes (CNTs) to affect the crystallization behavior of the polymers. Isotactic Polypropylene (iPP) is very widely used and is a good model system to understand the physics of other similar polymers. iPP/CNT PNCs form α, β, and γ crystallographic phases under a variety of crystallization conditions: non-isothermal and isothermal melt crystallization, shear, stress, fiber extrusion, etc. The crystal growth is altered from spherulitic to α-fibrillar upon the nucleation effect of CNTs. We are studying the effect of different temperature treatment schemes and different isothermal crystallization conditions. We found also that the smectic ordering in iPP is improved by the introduction of CNTs. We use Differential Scanning Calorimetry, Wide Angle X-ray scattering, Microscopic Transmission Ellipsometry and Avrami analysis. Research supported by: Assumption College Faculty Development Grant, funding for students' stipends, instrumentation and supplies, the NSF Polymers Program of the DMR, grant (DMR-0602473) and NASA grant (NAG8-1167).

  10. 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.

  11. Tailoring the wettability of polypropylene surfaces with halloysite nanotubes.

    Science.gov (United States)

    Liu, Mingxian; Jia, Zhixin; Liu, Fang; Jia, Demin; Guo, Baochun

    2010-10-01

    In this contribution, halloysite nanotubes (HNTs), a kind of natural hydrophilic nanoclay, are incorporated into polypropylene (PP) for tailoring the surface microstructures of the composites prepared by solution casting. HNTs act as heterogeneous nuclei for PP, which leads to the change of phase separation process during drying of the composites and consequently the microstructures of composite surfaces. Micro-papilla like hybrid spherulites with nanostructures are formed on the PP/HNTs composite surfaces. The rough surfaces demonstrate superhydrophobicity with a maximum water contact angle as nearly 170 degrees and sliding angle of about 2 degrees. The spherulites size, surface roughness, and wetting property of PP can be tuned by HNTs. HNTs can significantly improve the thermal degradation behavior of the composites which is attributed to the well-dispersed HNTs and the improved interfacial interactions by the nucleation effect. The present work provides an alternative routine for preparing polymer superhydrophobic surfaces via tailoring the surface microstructures by adding nanoparticles in a solution process.

  12. Extensional Flow-Induced Dynamic Phase Transitions in Isotactic Polypropylene.

    Science.gov (United States)

    Ju, Jianzhu; Wang, Zhen; Su, Fengmei; Ji, Youxin; Yang, Haoran; Chang, Jiarui; Ali, Sarmad; Li, Xiangyang; Li, Liangbin

    2016-09-01

    With a combination of fast extension rheometer and in situ synchrotron radiation ultra-fast small- and wide-angle X-ray scattering, flow-induced crystallization (FIC) of isotactic polypropylene (iPP) is studied at temperatures below and above the melting point of α crystals (Tmα). A flow phase diagram of iPP is constructed in strain rate-temperature space, composing of melt, non-crystalline shish, α and α&β coexistence regions, based on which the kinetic and dynamic competitions among these four phases are discussed. Above Tmα , imposing strong flow reverses thermodynamic stabilities of the disordered melt and the ordered phases, leading to the occurrence of FIC of β and α crystals as a dynamic phase transition. Either increasing temperature or stain rate favors the competiveness of the metastable β over the stable α crystals, which is attributed to kinetic rate rather than thermodynamic stability. The violent competitions among four phases near the boundary of crystal-melt may frustrate crystallization and result in the non-crystalline shish winning out.

  13. Glass Fiber Reinforced Polypropylene Mechanical Properties Enhancement by Adhesion Improvement

    Directory of Open Access Journals (Sweden)

    Mariana Etcheverry

    2012-06-01

    Full Text Available Glass fibers (GF are the reinforcement agent most used in polypropylene (PP based composites, as they have good balance between properties and costs. However, their final properties are mainly determined by the strength and stability of the polymer-fiber interphase. Fibers do not act as an effective reinforcing material when the adhesion is weak. Also, the adhesion between phases can be easily degraded in aggressive environmental conditions such as high temperatures and/or elevated moisture, and by the stress fields to which the material may be exposed. Many efforts have been done to improve polymer-glass fiber adhesion by compatibility enhancement. The most used techniques include modifications in glass surface, polymer matrix and/or both. However, the results obtained do not show a good costs/properties improvement relationship. The aim of this work is to perform an accurate analysis regarding methods for GF/PP adhesion improvement and to propose a new route based on PP in-situ polymerization onto fibers. This route involves the modification of fibers with an aluminum alkyl and hydroxy-α-olefin and from there to enable the growth of the PP chains using direct metallocenic copolymerization. The adhesion improvements were further proved by fragmentation test, as well as by mechanical properties measurements. The strength and toughness increases three times and the interfacial strength duplicates in PP/GF composites prepared with in-situ polymerized fibers.

  14. Radiation Effects on Polypropylene Carbon Nanofibers Composites: Spectroscopic Investigations

    Science.gov (United States)

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

    2010-03-01

    Dispersion of carbon nanostructures within polymeric matrices affects their physical and chemical properties (increased Young modulus, improved thermal stability, faster crystallization rates, higher equilibrium degree of crystallinity, modified glass, melting, and crystallization temperatures, enhanced thermal and electrical conductivity). Nevertheless, little is known about the radiation stability of such nanocomposites. The research is focused on spectroscopic investigations of radiation-induced modifications in isotactic polypropylene (iPP)-vapor grown nanofiber (VGCNF) composites. VGCNF were dispersed within iPP by extrusion at 180^oC. Composites containing various amounts of VGCNFs ranging from 0 to 20 % wt. were prepared and subjected to gamma irradiation, at room temperature, at various integral doses (10 MGy, 20 MGy, and 30 MGy). Raman spectroscopy, ATR, and WAXS were used to assess the radiation-induced modifications in these nanocomposites. Acknowledgements: This research was supported by the Welch Foundation (Department of Chemistry at UTPA), by Air Force Research Laboratory (FA8650-07-2-5061) and by US Army Research Laboratory/Office (W911NF-08-1-0353).

  15. Colorectal cancer incidence among polypropylene manufacturing workers. An update.

    Science.gov (United States)

    Lewis, R J; Schnatter, A R; Lerman, S E

    1994-06-01

    This study updates an earlier investigation that found a sixfold excess incidence of colorectal cancer among polypropylene workers for the period January 1960 to September 1985. The study cohort comprised 412 male workers with at least 6 months employment and 10 years latency. For the extended follow-up period (October 1985 to May 1992), the standardized incidence ratio (SIR) based on state comparison rates was slightly elevated and not statistically significant (SIR = 1.5, 95% confidence interval [CI] = 0.5 to 3.5). A 2.3-fold excess was observed among process workers (95% CI = 0.3 to 8.2), but this was based on only two cases. Risk among process/mechanical workers was greater for short-term workers ( or = 10 years, SIR = 0.7, 95% CI = 0.02 to 4.0). Overall, the update findings do not suggest an occupationally related risk. Possible influences of company-sponsored colorectal cancer screening, the polyolefin unit shutdown, and other factors are discussed.

  16. Local dielectric permittivity profiles of sapphire/polypropylene interfaces

    Science.gov (United States)

    Yu, Liping; Ranjan, V.; Buongiorno Nardelli, M.; Bernholc, J.

    2009-03-01

    Recently, the need for high-power-density capacitors has stimulated research to develop composite dielectric materials with high-k nanoparticles embedded in a polymer matrix. In these materials, surfaces and interfaces may play an important role in determining the overall dielectric properties. We present first-principles investigations of the dielectric permittivity profiles across slabs and interfaces of sapphire(α-Al2O3)/isotactic-polypropylene(iPP). Our results indicate that the permittivity profile at interface strongly depends on the nanoscale averaging procedure. We propose an averaging model that ensures near-locality of the dielectric function. We find that: (i) the dielectric permittivity approaches the corresponding bulk value just a few atomic layers away from the interface or surface; (ii) the dielectric constant is enhanced at the surfaces of the isolated α-Al2O3 slabs, while no enhancement is observed at the iPP slab surfaces; and (iii) the dielectric transition at the αAl2O3/iPP is mainly confined in the αAl2O3 side.

  17. SAXS Study of Reversibly Crosslinked Isotactic Polypropylene/clay Nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Bouhelal, S.; Cagiao, M; Benachour, D; Djellouli, B; Rong, L; Hsiao, B; Baltá-Calleja, F

    2010-01-01

    A new route based on reversibly crosslinking reactive extrusion is applied for the development of iPP/clay nanocomposites. Analysis of small-angle X-ray scattering (SAXS) reflections of isotactic polypropylene (iPP)/clay nanocomposites, prepared by two different mixing and chemical crosslinking methods (i.e., conventional and in situ), is presented and results are compared with preceding wide-angle X-ray diffraction (WAXD) results. It is shown that the presence of clay significantly affects the value of long spacing in iPP, as well as the coherence length of lamellar stacks. Results show that the size of the coherently diffracting nanodomains decreases in two stages, first rapidly and then slowly as a function of increasing clay content. This can be attributed to the influence of confined iPP lamellae under the effect of rising number of clay particles. The appearance of the {gamma}-crystalline form in the crosslinked iPP/clay nanocomposites is related with the difficulty in chain folding of iPP chains introduced by the chemical crosslinking process, as well as by the presence of clay particles.

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

    Directory of Open Access Journals (Sweden)

    Kohei Takahara

    2013-01-01

    Full Text Available 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 unnecessary surgery.

  19. Chronic complaints after simple sutured repair for umbilical or epigastric hernias may be related to recurrence

    DEFF Research Database (Denmark)

    Westen, Mikkel; Christoffersen, Mette W; Jorgensen, Lars N;

    2014-01-01

    PURPOSE: Umbilical and epigastric hernia repairs are minor, but are commonly conducted surgical procedures. Long-term results have only been sparsely investigated. Our objective was to investigate the risk of chronic complaints after a simple sutured repair for small umbilical and epigastric...... hernias. METHODS: A retrospective cohort study with a 5-year questionnaire and clinical follow-up was conducted. Patients undergoing primary elective, open non-mesh umbilical or epigastric sutured hernia repair were included. Patients completed a structured questionnaire regarding chronic complaints...

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

    Directory of Open Access Journals (Sweden)

    Michele Regina Rosa Hamester

    2012-04-01

    Full Text Available There is a high content of calcium carbonate in mussel and oyster shells, which can be used in the formulation of medicine, in construction or as filler in polymer materials. This work has as its main objective to obtain calcium carbonate from mussel and oyster shells and used as filler in polypropylene compared their properties with polypropylene and commercial calcium carbonate composites. The shellfish was milling and heated at 500 ºC for 2 hours. The powder obtained from shellfish were characterized by scanning electron microscopy (SEM, X-ray fluorescence, particle size distribution and abrasiveness and compared with commercial CaCO3 and mixed with polypropylene. The thermal and mechanical properties of polypropylene with CaCO3 obtained from oyster and mussel shells and with commercial CaCO3 were analysed. The results showed that CaCO3­ can be obtained from oyster and mussel shell and is technically possible to replace the commercial CaCO3 for that obtained from the shells of shellfish in polypropylene composites.

  1. Histopathological Comparison of Mosquito Net with Polypropylene Mesh for Hernia Repair: An Experimental Study in Rats.

    Science.gov (United States)

    Sharma, Mukesh; Sharma, Deepti Bala; Chandrakar, Shiv Kumar; Sharma, Dhananjaya

    2015-12-01

    Use of mosquito net, in place of polypropylene mesh, had been reported for tension-free hernia repair, as a better cost-effective option. This experimental histopathological study was performed in rats to find out the tissue response and the foreign body reaction and its comparison between commercial polypropylene mesh and the sterilized mosquito net. This experimental study was conducted in the Department of Surgery, Government NSCB, Medical College, Jabalpur (Madhya Pradesh), India. It was carried out in 40 albino rats. A 1.5 × 0.5-cm hernial defect was created by excising full-thickness abdominal wall muscle. All rats underwent on-lay mesh repair of hernial defect (polypropylene mesh, n = 20; mosquito net, n = 20). Half of rats in each group were sacrificed on day 14, and the other half, on day 90. Sections of containing mesh were examined histopathologically for inflammatory infiltrate, giant cells, and collagen deposition. Mosquito net group showed significantly greater number of giant cells and inflammatory cells at 14 and 90 days (p  0.05 and p > 0.05, respectively). Results of mosquito net are comparable to conventional polypropylene mesh. In a setup, where cost-effectiveness is of primary importance, use of mosquito net for tension-free hernia repair can be an acceptable alternative as proven histologically, to commercially available polypropylene mesh.

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

    NARCIS (Netherlands)

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

    2011-01-01

    Purpose: This study evaluated the in vitro plaque inhibitory effect of triclosan-coated polyglactin 910 sutures in the absence and presence of an additional antiplaque agent commonly used after oral surgery. Materials and Methods: Triclosan-coated sutures were incubated for 4 hours in freshly collec

  3. 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 μm) 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.

  4. Estudio comparativo de microsutura vascular en ratas: punto simple y punto de colchonero horizontal Comparative study about vascular microsurgery on rats: classic interrupted suture versus horizontal mattress suture

    Directory of Open Access Journals (Sweden)

    C. Casado Sánchez

    2009-09-01

    Full Text Available La Microcirugía es la técnica empleada para la realización de la microanastomosis vascular. El objetivo del presente estudio es comparar dos tipos de técnicas de microsutura: los puntos simples clásicos, de empleo habitual en la microcirugía vascular, y los puntos de colchonero horizontales, no evaluados habitualmente para este tipo de cirugía. Fueron intervenidas 20 ratas albinas de la cepa Wistar (peso medio de 250 - 300 gr. bajo anestesia general; realizamos sección transversal en la arteria femoral, procediendo a su reparación microquirúrgica inmediata. Se establecieron 2 grupos de animales: en el grupo A (n=10, la microsutura se hizo mediante 6 puntos sueltos simples, y en el grupo B (n=10, empleando 3 puntos de colchonero horizontal. Comprobamos la patencia en el desclampado inmediato y tras una hora del desclampado (para ambas técnicas fue positiva en el 100% de los casos, y la hemorragia en ambos tiempos (se registró un único caso de sangrado en el postoperatorio inmediato en el grupo B, que requirió la revisión de la microsutura. El tiempo medio de ejecución de la sutura en el grupo B, 15 minutos aproximadamente, fue más corto que en el grupo A, 21 minutos aproximadamente, diferencia estadísticamente significativa (p Microsurgery is the procedure of choice for vascular microanastamoses. The objective of this study was to compare two types of suture techniques: classic interrupted suture anastomoses, commonly used for vascular anastamoses in microsurgery, and another technique using horizontal mattress sutures, rarely evaluated in this type of surgery. Twenty albino Wistar rats were operated (average weight: 250 - 300 gr. under general anaesthesia. A transverse section of the femoral artery was performed and immediately followed by an anastamoses. The animals were placed into two groups of ten. The classic 6 interrupted suture anastomoses technique was performed in group A (n = 10 and another technique using 3

  5. Evaluation of Properties of Unidirectional Hemp/Polypropylene Composites: Influence of Fiber Content and Fiber/Matrix Interface Variables

    DEFF Research Database (Denmark)

    Plackett, David; Løgstrup Andersen, Tom; Lilholt, Hans

    2002-01-01

    Flament-wound textile hemp yarn was used in combination with unmodified or maleated polypropylene (PP) films to produce plates of unidirectional composites.......Flament-wound textile hemp yarn was used in combination with unmodified or maleated polypropylene (PP) films to produce plates of unidirectional composites....

  6. Biocomposites from abaca strands and polypropylene. Part I: Evaluation of the tensile properties.

    Science.gov (United States)

    Vilaseca, Fabiola; Valadez-Gonzalez, Alex; Herrera-Franco, Pedro J; Pèlach, M Angels; López, Joan Pere; Mutjé, Pere

    2010-01-01

    In this paper, abaca strands were used as reinforcement of polypropylene matrix and their tensile mechanical properties were studied. It was found relevant increments on the tensile properties of the abaca strand-PP composites despite the lack of good adhesion at fiber-matrix interface. Afterwards, it was stated the influence of using maleated polypropylene (MAPP) as compatibilizer to promote the interaction between abaca strands and polypropylene. The intrinsic mechanical properties of the reinforcement were evaluated and used for modeling both the tensile strength and elastic modulus of the composites. For these cases, the compatibility factor for the ultimate tensile strength was deduced from the modified rule of mixtures. Additionally, the experimental fiber orientation coefficient was measured, allowing determining the interfacial shear strengths of the composites and the critical fiber length of the abaca strand reinforcement. The mechanical improvement was compared to that obtained for fiberglass-reinforced PP composites and evaluated under an economical and technical point of view.

  7. Key Role of Reinforcing Structures in the Flame Retardant Performance of Self-Reinforced Polypropylene Composites

    Directory of Open Access Journals (Sweden)

    Katalin Bocz

    2016-08-01

    Full Text Available The flame retardant synergism between highly stretched polymer fibres and intumescent flame retardant systems was investigated in self-reinforced polypropylene composites. It was found that the structure of reinforcement, such as degree of molecular orientation, fibre alignment and weave type, has a particular effect on the fire performance of the intumescent system. As little as 7.2 wt % additive content, one third of the amount needed in non-reinforced polypropylene matrix, was sufficient to reach a UL-94 V-0 rating. The best result was found in self-reinforced polypropylene composites reinforced with unidirectional fibres. In addition to the fire retardant performance, the mechanical properties were also evaluated. The maximum was found at optimal consolidation temperature, while the flame retardant additive in the matrix did not influence the mechanical performance up to the investigated 13 wt % concentration.

  8. 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.

  9. Interfacial enhancement of polypropylene composites modified with sorbitol derivatives and siloxane-silsesquioxane resin

    Energy Technology Data Exchange (ETDEWEB)

    Dobrzyńska-Mizera, Monika, E-mail: monika.dobrzynska-mizera@doctorate.put.poznan.pl; Sterzyński, Tomasz [Poznan University of Technology, Institute of Materials Technology, Polymer Division, Piotrowo, 3, 61-138 Poznan (Poland); Dutkiewicz, Michał [Centre for Advanced Technologies, Adam Mickiewicz University, Umultowska 89 C, 61-614 Poznan (Poland); Di Lorenzo, Maria Laura [Consiglio Nazionale delle Ricerche, Istituto per i Polimeri, Compositi e Biomateriali, c/o Comprensorio Olivetti, Via Campi Flegrei, 34, 80078 Pozzuoli (Italy)

    2015-12-17

    Composites based on polypropylene (iPP) modified with a sorbitol derivative (NX8000) and siloxane-silsesquioxane resin (SiOPh) containing maleated polypropylene (MAPP) as compatibilizer were prepared by melt extrusion. Calorimetric investigations were carried out using differential scanning calorimetry (DSC), whereas the morphological and mechanical properties were investigated by scanning electron microscopy (SEM) and static tensile tests. DSC measurements revealed no influence of SiOPh and a slight effect of MAPP addition on the crystallization kinetics of polypropylene. Additionally, the introduction of MAPP into the iPP+NX8000+SiOPh composites increased plastic properties of the samples. All the above was attributed to the compatibilizing effect of MAPP which improved interfacial adhesion between iPP, NX8000 and SiOPh. This phenomenon was also confirmed by the SEM images illustrating more homogenous distribution of the filler in the compatibilized samples.

  10. Coir dust reinforced recycled polypropylene composites; Compositos de polipropileno reciclado e po de coco

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Bianca B. dos; Costa, Marysilvia F. da; Thire, Rossana M. da S.M., E-mail: bianca@metalmat.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    The environmental impacts caused by disposed plastics encourage the search for new alternatives. Recycling polymers leads to the degradation of their mechanical properties, which can be modified by the addition of fillers. In this paper, recycled polypropylene from plastic cups with 2%, 5% and 10% of coir dust were produced with and without the addition of additives. These composites were characterized by tensile tests, X-ray diffraction, differential scanning calorimetry and scanning electron microscopy on the fracture surface. It was verified the effectiveness of the addition of coir dust in improving the elasticity modulus of recycled polypropylene besides the effectiveness of additives used in promoting the adhesion of the powder to the matrix. However, higher levels of coir dust caused the appearance of air bubbles inside the material, which contributed to its embrittlement. The addition of coir dust promoted a decrease in the degree of polypropylene crystallinity. (author)

  11. Characterization of gypsum plasterboard with polyurethane foam waste reinforced with polypropylene fibers

    Directory of Open Access Journals (Sweden)

    L. Alameda

    2016-09-01

    Full Text Available Gypsum plasterboard that incorporates various combinations of polyurethane foam waste and polypropylene fibers in its matrix is studied. The prefabricated material was characterized in a series of standardized tests: bulk density, maximum breaking load under flexion stress, total water absorption, surface hardness, thermal properties, and reaction to fire performance. Polypropylene fibers were added to the polyurethane gypsum composites to improve the mechanical behavior of the plasterboard under loading. The results indicate that increased quantities of polymer waste led to significant reductions in the weight/surface ratio, the mechanical strength and the surface hardness of the gypsum, as well as improving its thermal resistance. The polypropylene fibers showed good adhesion to the polymer and the gypsum matrix, which enhanced the mechanical performance and the absorption capacity of these compounds. The non-combustibility test demonstrated the potential of the new material for use in internal linings.

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

    DEFF Research Database (Denmark)

    Drozdov, Aleksey; Christiansen, Jesper de Claville; Sanporean, Catalina-Gabriela

    2012-01-01

    Purpose – The purpose of this paper is to perform experimental investigation and constitutive modeling of the viscoelastic and viscoplastic behavior of metallocene catalyzed polypropylene (mPP) with application to lifetime assessment under conditions of creep rupture. Design/methodology/approach ...... 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....../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......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...

  13. Performance of polypropylene and steel tubes in solar water heaters with natural circulation

    Energy Technology Data Exchange (ETDEWEB)

    Riazi, M.R. [Kuwait Univ., Safat (Kuwait). Chemical Engineering Dept.; Razavi, J. [Sharif Univ. of Technology, Tehran (Iran, Islamic Republic of). Chemical Engineering Dept.

    1997-02-01

    Performance of solar water heaters in thermosyphonic flow with polypropylene and steel tubes was studied experimentally. An experimental apparatus consisting of 36 south-facing parallel tubes was designed and built especially for this study. Experiments were performed at Sharif University of Technology in Tehran during July--August 1994 from 0900 to 1700, when the ambient temperature varied from 29 to 36 C. Overall, 30 experiments were conducted for both types of tubes. At first, it was found that the best collector slope for both types of tubes was 36{degree} and it is independent of tube type. Generally, it was found that polypropylene tubes under similar conditions can increase water temperature by 10 C more than steel tubes. Based on the results shown in this study, use of polypropylene tubes in solar water heating systems is recommended.

  14. Microcrystalline-cellulose and polypropylene based composite: A simple, selective and effective material for microwavable packaging.

    Science.gov (United States)

    Ummartyotin, S; Pechyen, C

    2016-05-20

    Cellulose based composite was successfully designed as active packaging with additional feature of microwavable properties. Small amount of cellulose with 10 μm in diameter was integrated into polypropylene matrix. The use of maleic anhydride was employed as coupling agent. Thermal and mechanical properties of cellulose based composite were superior depending on polypropylene matrix. Crystallization temperature and compressive strength were estimated to be 130 °C and 5.5 MPa. The crystal formation and its percentage were therefore estimated to be 50% and it can be predicted on the feasibility of microwavable packaging. Morphological properties of cellulose based composite presented the good distribution and excellent uniformity. It was remarkable to note that cellulose derived from cotton can be prepared as composite with polypropylene matrix. It can be used as packaging for microwave application.

  15. An experimental comparative study between polypropylene and laminated lower limb prosthetic socket

    Directory of Open Access Journals (Sweden)

    .Haider F. Neama, M.Sc

    2007-01-01

    Full Text Available Most researchers concentrate their studies on the design, stress and pressure distributions of the prosthetic socket. A little attention is considered for the stiffness of the various materials of the prosthetic sockets. Prosthetic laminated sockets in Iraq are costly to be manufactured while polypropylene socket is relatively cheap in comparing with the laminates. Experimental study is conducted to compare the stiffness of five prosthetic sockets made of different materials. Compression, three point flexural and tensile tests are implemented by the Testometric machine. The laminate sockets give better results in compression than polypropylene. Polypropylene gives good results in bending compared with the laminate sockets. When the socket loads are mainly in compression i.e. the low activity level patients, it seems that any of the tested sockets could be used, however, when the load will be not only in compression but in flexion as well i.e. high activity patients, socket No.1 and 5 could be used

  16. Interfacial enhancement of polypropylene composites modified with sorbitol derivatives and siloxane-silsesquioxane resin

    Science.gov (United States)

    Dobrzyńska-Mizera, Monika; Dutkiewicz, Michał; Sterzyński, Tomasz; Di Lorenzo, Maria Laura

    2015-12-01

    Composites based on polypropylene (iPP) modified with a sorbitol derivative (NX8000) and siloxane-silsesquioxane resin (SiOPh) containing maleated polypropylene (MAPP) as compatibilizer were prepared by melt extrusion. Calorimetric investigations were carried out using differential scanning calorimetry (DSC), whereas the morphological and mechanical properties were investigated by scanning electron microscopy (SEM) and static tensile tests. DSC measurements revealed no influence of SiOPh and a slight effect of MAPP addition on the crystallization kinetics of polypropylene. Additionally, the introduction of MAPP into the iPP+NX8000+SiOPh composites increased plastic properties of the samples. All the above was attributed to the compatibilizing effect of MAPP which improved interfacial adhesion between iPP, NX8000 and SiOPh. This phenomenon was also confirmed by the SEM images illustrating more homogenous distribution of the filler in the compatibilized samples.

  17. 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)

  18. Characterization of the Microstructure Changes of Polypropylene Induced by Pan-milling

    Institute of Scientific and Technical Information of China (English)

    卢灿辉; 王琪

    2002-01-01

    The microstructure changes of polypropylene induced by a complex combination of shearing, friction, compression and stretching actions during pan-milling were revealed by spectroscopic techniques. X-ray diffraction analysis showed that the structure of polypropylene transferred from crystal into amorphous after undergoing enough milling operation. No transformation between crystal forms was observed. The study of the high-frequency region of the Raman spectrum between 2800 and 3100cm-1 of polypropylene indicated that molecular motion and chain deformation of PP led to amorphization and deterioration of packing regularity during pan-milling. By co-panmilling PP with bis-(2,2,6,6-tetramethyl-4-piperidinyl) sebacate under ambient condition, ESR signals of free radicals formed by mechanochemical scission of main chain were observed, and an increase of ESR intensity with milling was detected.

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

    Directory of Open Access Journals (Sweden)

    Jutarat Prachayawarakorn

    2005-03-01

    Full Text Available This research concerned with the use of rice husk (Oryza sativa as a filler for polypropylene and its recycle ability. Rice husk (200 mesh and 40% by weight and polypropylene were compounded in a twinscrew extruder and injection moulding technique was applied in order to obtain testing specimens. It was found that tensile, flexural and impact properties as well as % water absorption of the rice husk-filled polypropylene were only slightly dropped upon recycling process, presenting the ability of the rice husk- filledpolypropylene samples to recycle. The increase in melt flow index of the samples was also obtained. In addition, SEM micrographs revealed the reduction of rice husk particle size by the recycling process. Moreover, FTIR spectroscopy and TGA technique were performed for characterizing the filled specimens.

  20. Poly(acrylic acid surface grafted polypropylene films: Near surface and bulk mechanical response

    Directory of Open Access Journals (Sweden)

    2008-11-01

    Full Text Available Radical photo-grafting polymerization constitutes a promising technique for introducing functional groups onto surfaces of polypropylene films. According to their final use, surface grafting should be done without affecting overall mechanical properties. In this work the tensile drawing, fracture and biaxial impact response of biaxially oriented polypropylene commercial films grafted with poly(acrylic acid (PAA were investigated in terms of film orientation and surface modification. The variations of surface roughness, elastic modulus, hardness and resistance to permanent deformation induced by the chemical treatment were assessed by depth sensing indentation. As a consequence of chemical modification the optical, transport and wettability properties of the films were successfully varied. The introduced chains generated a PAA-grafted layer, which is stiffer and harder than the neat polypropylene surface. Regardless of the surface changes, it was proven that this kind of grafting procedure does not detriment bulk mechanical properties of the PP film.

  1. 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)

  2. A novel suturing approach for tissue displacement within minimally invasive periodontal plastic surgery.

    Science.gov (United States)

    Ronco, Vincent; Dard, Michel

    2016-08-01

    This paper describes a novel suturing approach that achieves harmonious and atraumatic soft tissue displacement in periodontal plastic surgery and soft tissue management around implants. The technique relies on a combination of horizontal and vertical mattress that are anchored at the splinted incisal contact points.

  3. A novel suturing approach for tissue displacement within minimally invasive periodontal plastic surgery

    OpenAIRE

    Ronco, Vincent; Dard, Michel

    2016-01-01

    Key Clinical Message This paper describes a novel suturing approach that achieves harmonious and atraumatic soft tissue displacement in periodontal plastic surgery and soft tissue management around implants. The technique relies on a combination of horizontal and vertical mattress that are anchored at the splinted incisal contact points.

  4. A comparison of the effects of packing or transseptal suture on polysomnographic parameters in septoplasty.

    Science.gov (United States)

    Turhan, Murat; Bostancı, Aslı; Akdag, Mehmet; Dinc, Oktay

    2013-03-01

    Our objective is to examine the effects of using nasal packing or transseptal suture in septoplasty in young patients, specifically on the polysomnographic parameters in the post-operative period. A total of 43 patients who had undergone septoplasty surgery after a diagnosis of septum deviation were included in the study. Packing was inserted in 23 patients, and transseptal suture was performed in the other 20 patients. A polysomnography test was performed on the patients on the first day after surgery and during the post-operative period. A post-operative increase was found in the apnea-hypopnea index (AHI) within both the packing and suture groups. The AHI increase in the packing group was statistically significant (p packing group was significantly higher compared to suture group (p packing group (p packing in young patients after septoplasty surgery reduced the quality of life after surgery and had negative effects on respiration during sleep. The finding that nasal packing caused obstructive sleep apnea syndrome even in young patients leads us to hypothesise that the effect of the packing on comorbid patients' respiratory function during sleep would be even more severe.

  5. Acute distal tibiofibular syndesmosis injury: A systematic review of suture-button versus syndesmotic screw repair

    NARCIS (Netherlands)

    T. Schepers (Tim)

    2012-01-01

    textabstractPurpose: Recently, a new suture-button fixation device has emerged for the treatment of acute distal tibiofibular syndesmotic injuries and its use is rapidly increasing. The current systematic review was undertaken to compare the biomechanical properties, functional outcome, need for imp

  6. Effect of end-to-end invagination pancreaticojejunostomy with circle discontinuous U suture in pancreatic surgery

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xuewen; XUAN Wei; JIANG Tao; JI Degang; YANG Yongsheng; ZHANG Dan; XIE Yingjun; MENG Zihui; ZHAO Jisheng

    2007-01-01

    The aim of this paper is to summarize the methods of pancreaficojejunostomy in the pancreatic operation and to study the safety and feasibility of a new operative method called end-to-end invagination pancreaticojejunostomy with circle discontinuous U suture to prevent fistula of pancreaticojejunostomy.Eight-three patients with pancreaticoduodenectomy in the 3rd Hospital,Jilin University from 2001 January to 2006 April were reviewed.The incidences of pancreatic fistula with different types of pancreaticojejunostomy were compared.The overall incidence rate of pancreatic fistula was 26.5% (22/83).No pancreatic fistula occurred in end-to-end invagination pancreaticojejunostomy with circle discontinuous U suture.The incidence rate of the fistula following end-to-end invagination pancreaticojejunostomy with circle discontinuous U suture was significantly lower than that of traditional end-to-end pancreaticojejunostomy [40%,(10/25),P<0.01] and end-to-side pancreaticojejunostomy [27.3%,(12/44),P < 0.05],but no significant difference (P>0.05) between traditional end-to-end pancreaticojejunostomy and end-to-side pancreaticojejunostomywas discovered.End-to-end invagination pancreaticojejunostomy with circle discontinuous U suture has a definite effect on avoiding pancreatic fistula following pancreaticojejunostomy and is worth being recommended.But the cases were limited,so this method would still need to be observed and confirmed further in the future.

  7. Interference Screw vs. Suture Anchor Fixation for Open Subpectoral Biceps Tenodesis: Does it Matter?

    Directory of Open Access Journals (Sweden)

    Gobezie Reuben

    2008-09-01

    Full Text Available Abstract Background Bioabsorbable interference screw fixation has superior biomechanical properties compared to suture anchor fixation for biceps tenodesis. However, it is unknown whether fixation technique influences clinical results. Hypothesis We hypothesize that subpectoral interference screw fixation offers relevant clinical advantages over suture anchor fixation for biceps tenodesis. Study Design Case Series. Methods We performed a retrospective review of a consecutive series of 88 patients receiving open subpectoral biceps tenodesis with either interference screw fixation (34 patients or suture anchor fixation (54 patients. Average follow up was 13 months. Outcomes included Visual Analogue Pain Scale (0–10, ASES score, modified Constant score, pain at the tenodesis site, failure of fixation, cosmesis, deformity (popeye and complications. Results There were no failures of fixation in this study. All patients showed significant improvement between their preoperative and postoperative status with regard to pain, ASES score, and abbreviated modified Constant scores. When comparing IF screw versus anchor outcomes, there was no statistical significance difference for VAS (p = 0.4, ASES score (p = 0.2, and modified Constant score (P = 0.09. One patient (3% treated with IF screw complained of persistent bicipital groove tenderness, versus four patients (7% in the SA group (nonsignificant. Conclusion Subpectoral biceps tenodesis reliably relieves pain and improves function. There was no statistically significant difference in the outcomes studied between the two fixation techniques. Residual pain at the site of tenodesis may be an issue when suture anchors are used in the subpectoral location.

  8. Arthroscopic double-row suture anchor fixation of minimally displaced greater tuberosity fractures.

    Science.gov (United States)

    Ji, Jong-Hun; Kim, Weon-Yoo; Ra, Ki-Hang

    2007-10-01

    In cases of displaced greater tuberosity fractures, treatments by arthroscopic-assisted reduction and percutaneous screw fixation have been reported. However, in cases in which there is a comminuted fracture or a minimally displaced fracture combined with concomitant lesions such as rotator cuff tear or labral pathology, it is difficult to reduce the fracture and to treat other pathologies by use of a percutaneous screw. Recently, many surgeons have used the double-row repair method in rotator cuff repair, which provides a tendon-bone interface better suited for biologic healing and restoring normal anatomy. In accordance with this method, we used the arthroscopic technique of double-row suture anchor fixation for a minimally displaced greater tuberosity fracture without additional incision. Initially, debridement was performed on the fracture surface by use of a shaver, and the medial-row anchor was inserted through the anterior portal or the intact cuff. Two lateral-row anchors were inserted just anterior and posterior to the lower margin of the fractured fragment under C-arm guidance. The medial-row sutures and lateral-row sutures were then placed. Arthroscopic double-row suture anchor fixation of a displaced greater tuberosity fracture restores the original footprint of the rotator cuff and normal tendon-bone interface of the displaced greater tuberosity fracture.

  9. Role of suture anchors in management of fractures of inferior pole of patella

    Directory of Open Access Journals (Sweden)

    Anand Ashish

    2010-01-01

    Full Text Available Background: The traditional recommendation for displaced comminuted inferior pole fractures is excision of the comminuted pole followed by reattachment of the patellar tendon with transosseous suture. To the best of our knowledge there has been no previous published study mentioning the use of suture anchors for fracture inferior pole of patella. We present a retrospective analysis of five cases of patients doing well at final follow-up of two years. Materials and Methods: Five patients treated at our institute using suture anchors for repair of comminuted inferior pole fractures of patella between January 2007 to March 2007. (range 28 years-55 years. There were three males and two females. Results: The average follow-up was 25 months (range 24 months-26 months. The patients were evaluated for range of motion, strength, patellofemoral scores and any alteration of patellar height. The outcome of the procedure was assessed with use of the patellofemoral scoring system of Noyes et al, 5 as adapted by Saltzman et al. 6 The final patellofemoral score (maximum 100 points was 94.6 (range 93-96. Conclusion: We believe it is a novel extended indication of the use of suture anchors and should be in the armament of every trauma surgeon.

  10. A novel suture method to place and adjust peripheral nerve catheters

    DEFF Research Database (Denmark)

    Rothe, C.; Steen-Hansen, C.; Madsen, M. H.;

    2015-01-01

    We have developed a peripheral nerve catheter, attached to a needle, which works like an adjustable suture. We used in-plane ultrasound guidance to place 45 catheters close to the femoral, saphenous, sciatic and distal tibial nerves in cadaver legs. We displaced catheters after their initial...

  11. Conization of the cervix uteri. Complications in connection with plain catgut or silk suturing

    DEFF Research Database (Denmark)

    Holmskov, A; Qvist, N; Møller, A

    1984-01-01

    During a retrospective study on postoperative complications in 213 patients who had undergone conization, a (non-significant) reduction in the bleeding rate from 27.9% to 18.6% was found when using silk sutures (102 patients) instead of plain catgut (111 patients) for adaption of the edges of the...

  12. Subtotal cranial vault remodelling in anterior sagittal suture closure: impact of age on surgical outcome

    NARCIS (Netherlands)

    Engel, M.; Hoffmann, J.; Muhling, J.; Castrillon-Oberndorfer, G.; Seeberger, R.; Freudlsperger, C.

    2012-01-01

    Isolated fusion of the sagittal suture is usually treated before 1 year of age, but some patients present at a later age. The aim of this study was to evaluate the impact of children's age on the surgical outcome. The authors investigated 46 patients with isolated nonsyndromic sagittal craniosynosto

  13. 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

  14. A Wireless Sensor for Real-Time Monitoring of Tensile Force on Sutured Wound Sites.

    Science.gov (United States)

    DeRouin, Andrew; Pacella, Nina; Zhao, Chunfeng; An, Kai-Nan; Ong, Keat Ghee

    2016-08-01

    A new wireless sensor was designed, fabricated, and applied for in situ monitoring of tensile force at a wound site. The sensor was comprised of a thin strip of magnetoelastic material with its two ends connected to suture threads for securing the sensor across a wound repair site. Since the sensor was remotely interrogated by applying an ac magnetic field and capturing the resulting magnetic field, it did not require direct wire connections to an external device or internal battery for long-term use. Due to its magnetoelastic property, the application of a tensile force changed the magnetic permeability of the sensor, altering the amplitude of the measured magnetic field. This study presents two sensor designs: one for high and one for low-force ranges. A sensor was fabricated by directly adhering the magnetoelastic strip to the suture. This sensor showed good sensitivity at low force, but its response saturated at about 1.5 N. To monitor high tensile force, the magnetoelastic strip was attached to a metal strip for load sharing. The suture thread was attached to the both ends of the metal strip so only a fraction of the applied force was directed to the sensor, allowing it to exhibit good sensitivity even at 44.5 N. The sensor was applied to two ex vivo models: a sutured section of porcine skin and a whitetail deer Achilles tendon. The results demonstrate the potential for in vivo force monitoring at a wound repair site.

  15. Transpressive suture and flower structure: the Tomar-Badajoz-Cordoba shear zone, SW Iberia

    Science.gov (United States)

    Marti Linares, D.; Palomeras, I.; Perez-Estaun, A.; Carbonell, R.; Simancas, F.; Ayarza, P.; Tejero, R.; Martín-Parra, L.; Matas, J.; Lodeiro, F.; Mansilla, L.

    2009-12-01

    The Tomar-Badajoz-Córdoba shear Zone (TBCSZ) is a major structural element located in SW-Iberia. This is considered a suture that separates the Central Iberian Zone (CIZ) in NE and Ossa Morena Zone (OMZ) in SW. It is at least 380km in length and 10 to 20km width. It is a left lateral transpressive flower structure. The strike-slip displacement decays from SE to NW. Its axial zone includes a high grade metamorphic rock unit known as the Central Unit (CU) containing eclogites, and also suture lithotypes as ophiolites. It has been interpreted as a Variscan suture or a reworked Cadomian suture in intraplate regime during the Variscan cycle. This important structure has been imaged by 2 deep seismic reflection transects, the IBERSEIS in 2003 and more recently by ALCUDIA. The good quality of the seismic data sets constrains the internal architecture of this transpressional zone imaging a crustal scale flower structure. The structure features a north dipping wedge limited by two bands of reflectors that reach the middle crust (5 s). Beneath that and slightly to the north a wedge of relatively high amplitude reflectivity dips to the south into the mantle for 10-15 km. This structure is most probably the seismic signature of a complex structure result of deformation associated to a strike slip fault.

  16. 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.

  17. Differential expression of extracellular matrix-mediated pathways in single-suture craniosynostosis.

    Directory of Open Access Journals (Sweden)

    Brendan D Stamper

    Full Text Available Craniosynostosis is a disease defined by premature fusion of one or more cranial sutures. The mechanistic pathology of single-suture craniosynostosis is complex and while a number of genetic biomarkers and environmental predispositions have been identified, in many cases the causes remain controversial and inconclusive. In this study, gene expression data from 199 patients with isolated sagittal (n = 100, unilateral coronal (n = 50, and metopic (n = 49 synostosis are compared against both a control population (n = 50, as well as each other. After controlling for variables contributing to potential bias, FGF7, SFRP4, and VCAM1 emerged as genes associated with single-suture craniosynostosis due to their significantly large changes in gene expression compared to the control population. Pathway analysis implicated focal adhesion and extracellular matrix (ECM-receptor interaction as differentially regulated gene networks when comparing all cases of single-suture synostosis and controls. Lastly, overall gene expression was found to be highly conserved between coronal and metopic cases, as evidenced by the fact that WNT2 and IGFBP2 were the only genes differentially regulated to a significantly large extent in a direct comparison. The identification of genes and gene networks associated with Fgf/Igf/Wnt signaling and ECM-mediated focal adhesion not only support the involvement of biomarkers previously reported to be related to craniosynostosis, but also introduce novel transcripts and pathways that may play critical roles in its pathogenesis.

  18. 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.

  19. AN S- AND P-CONTAINING FLAME RETARDANT FOR POLYPROPYLENE

    Institute of Scientific and Technical Information of China (English)

    Hua-qiao Peng; De-yi Wang; Qian Zhou; Yu-zhong Wang

    2008-01-01

    A novel charring agent, bis(1-oxo-4-hydroxymethyl-2,6,7-trioxa-l-phosphabicyclo[2.2.2]octane) phenylphosphine sulfide (BCPPS), has been synthesized, and it is combined with ammonium polyphosphate (APP) and melamine phosphate (MP) to impart flame retardance and dripping resistance for polypropylene (PP). The fire performance of the treated PP is investigated by limiting oxygen index (LOI), vertical burning test (UL-94) and cone calorimeter, and the thermal stability and thermal oxidative stability of the composites are studied using thermogravimetric analysis (TG). It has been found that the treated PP with the optimal flame retardant formulation of APP:MP:BCPPS = 12:6:12 (weight ratio, formulation 10)gives an LOI of 31.3 and UL-94 V-0 rating. The results from cone calorimeter indicate that both the heat release rate (HRR)and the total heat evolved (THE) of IFR-PP (formulation 10) decrease significantly compared with those of neat PP. The TG result shows that the IFR-PP (formulation 10) has a high yield of residual char at high temperature. FTIR is used to investigate the residue of the treated PP that degrades at 400℃ for different time. The compact outer surface and the shaggy inner surface can be observed from the SEM graph of the residual chars after LOI test, which form a much better barrier for the transfer of heat and fuel during combustion and show good flame retardancy. Moreover, the treated PP and its residue are investigated by XPS analysis.

  20. Laser-induced selective copper plating of polypropylene surface

    Science.gov (United States)

    Ratautas, K.; Gedvilas, M.; Stankevičiene, I.; JagminienÄ--, A.; Norkus, E.; Li Pira, N.; Sinopoli, S.; Emanuele, U.; Račiukaitis, G.

    2016-03-01

    Laser writing for selective plating of electro-conductive lines for electronics has several significant advantages, compared to conventional printed circuit board technology. Firstly, this method is faster and cheaper at the prototyping stage. Secondly, material consumption is reduced, because it works selectively. However, the biggest merit of this method is potentiality to produce moulded interconnect device, enabling to create electronics on complex 3D surfaces, thus saving space, materials and cost of production. There are two basic techniques of laser writing for selective plating on plastics: the laser-induced selective activation (LISA) and laser direct structuring (LDS). In the LISA method, pure plastics without any dopant (filler) can be used. In the LDS method, special fillers are mixed in the polymer matrix. These fillers are activated during laser writing process, and, in the next processing step, the laser modified area can be selectively plated with metals. In this work, both methods of the laser writing for the selective plating of polymers were investigated and compared. For LDS approach, new material: polypropylene with carbon-based additives was tested using picosecond and nanosecond laser pulses. Different laser processing parameters (laser pulse energy, scanning speed, the number of scans, pulse durations, wavelength and overlapping of scanned lines) were applied in order to find out the optimal regime of activation. Areal selectivity tests showed a high plating resolution. The narrowest width of a copper-plated line was less than 23 μm. Finally, our material was applied to the prototype of the electronic circuit board on a 2D surface.

  1. A density functional theory study of the electronic structures and magnetic properties of Fe(1-x)Cox alloy nanowires encapsulated in (10,0) carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    Xie You; Zhang Jian-Min

    2011-01-01

    Under the generalized gradient approximation,the electronic structures and magnetic properties of Fe(1-x)Coxalloy nanowires encapsulated inside zigzag (10,0) carbon nanotubes (CNTs) are investigated systematically using firstprinciple density functional theory calculations.For the fully relaxed Fe(1-x)Cox/CNT structures,all the C atoms relax outwards,and thus the diameters of the CNTs are slightly increased.Formation energy analysis shows that the combining processes of all Fe(1-x)Cox/CNT systems are exothermic,and therefore the Fe(1-x)Cox alloy nanowirescan be encapsulated into semiconducting zigzag (10,0) CNTs and form stable hybrid structures.The charges are transferred from the Fe(1-x)Cox nanowires to the more electronegative CNTs,and the Fe-C/Co-C bonds formed have polar covalent bond characteristics.Both the spin polarization and total magnetic moment of the Fe(1-x)Cox/CNT system are smaller than those of the corresponding freestanding Fe(1-x)Cox nanowire,and the magnetic moment of the Fe(1-x)Cox/CNT system decreases monotonously with increasing Co concentration,but the Fe(1-x)Cox/CNT systems still have a large magnetic moment,implying that they can be utilized in high-density magnetic recording devices.

  2. Electronic Properties of Boron and Silicon Doped (10, 0 Zigzag Single-Walled Carbon Nanotube upon Gas Molecular Adsorption: A DFT Comparative Study

    Directory of Open Access Journals (Sweden)

    P. A. Gowri sankar

    2013-01-01

    Full Text Available We have performed a comparative study of nine predominant gas molecules (H2, H2O, O2, CO, CO2, NO, NO2, NH3, and CH3OH adsorption property on the top surface of the (10, 0 zigzag single-walled pristine Carbon nanotube (C-CNT, Boron doped carbon nanotube (B-CNT, and Silicon doped carbon nanotube (Si-CNT are investigated by using density functional theory (DFT computations to exploit their potential applications as gas sensors. For the first time, we calculated the optimal equilibrium position, absorption energy (Ead, and density of states (DOS of the considered gas molecules adsorbed on the open end of zigzag single-walled (10, 0 B-CNT and Si-CNT. Our first principle calculations demonstrate that the B-CNT and Si-CNT adsorbent materials are able to adsorb the considered gas molecules with variety of adsorption energy and their electronic structure dramatic changes in the density of states near the Fermi level. The obtained comparative DFT studies results are useful for designing a high-fidelity gas sensor materials and selective adsorbents for a selective gas sensor.

  3. CHARACTERISTICS OF STRUCTURE OF IMPACT COPOLYMERS OF POLYPROPYLENE WITH LOW ETHYLENE CONTENTS

    Institute of Scientific and Technical Information of China (English)

    MA Dezhu; LI Xiqiang; ZHANG Ruiyun; HONG Kunlun; LUO Xiaolie

    1994-01-01

    In the present work, the structure and impact properties of copolymers of polypropylene with low ethylene contents have been investigated. Based on the results of 13C-NMR, FTIR,WAXD, DSC, PLM and SEM, the relationship between impact properties and morphology of the copolymers has been discussed. The high impact properties of copolymer ICP2 may attribute to the relatively higher ethylene content and homogeneous ethylene unit distribution. The size and its distribution of spherulite in the copolymers and cycloid cavities dispersed in polypropylene continue phase may also be two important factors which affect the impact properties of these materials.

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

    Science.gov (United States)

    Wu, Xiumin; He, Mingjun; Yu, Haibo

    2013-03-01

    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.

  5. Effect of Wood Variables on the Properties of Wood Fiber-Polypropylene Composites

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The effect of wood species (Chinese fir and Poplar), wood fiber content (10%, 25%, 40%) and wood fiber sizes (16 to 32 mesh, 32-65 mesh, above 65 mesh) on the properties of the wood fiber-Polypropylene composites were studied in this paper. The results indicate that the effect of wood fiber content and size in composite were more important than that of chosen wood species. Compared with polypropylene without wood fiber, the flexural strength of the composites increased when adding wood fiber into polypr...

  6. Thermal analysis of polypropylene modified by gamma irradiation composites under outdoor conditions

    Energy Technology Data Exchange (ETDEWEB)

    Komatsu, Luiz G.H.; Oliani, Washington L.; Lugao, Ademar B.; Parra, Duclerc F., E-mail: dfparra@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    This work reports the influence of the clay in the degradation process of the HMSPP.The polypropylene (PP) was irradiated under acetylene atmosphere in gamma irradiation source ({sup 60}Co) to obtain the HMSPP (high melt strength polypropylene). Composites of HMSPP were processed in twin-screw extruder with clay Cloisite 20A and Maleic Anhydride (PP-g-MA) as coupling agent. The obtained composites were exposed under outdoor conditions for 6 months. The ageing effects were characterized by Differential Scanning Calorimetry (DSC), Thermogravimetry Analysis (TGA). Chemical oxidation was evaluated by Carbonyl Index (IC) through infrared Spectroscopy (FT-IR). The results showed correlation between carbonyl index and ageing time. (author)

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    Fereshteh Mirjalili

    2013-01-01

    Full Text Available 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 corresponding blends was characterized by means of spectrophotometry, polarized optical microscopy, scanning electron microscopy (SEM, FT-IR spectroscopy, differential scanning calorimetry (DSC, and tensile testing.

  9. Rate of heat transfer in polypropylene tubes in solar water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Razavi, J.; Mahmoodi, M. [Sharif University of Technology, Tehran (Iran). Chemical Engineering Dept.; Riazi, M.R. [Kuwait Univ., Safat (Kuwait). Chemical Engineering Dept.

    2003-06-01

    A heat transfer rate was determined for polypropylene tubes in solar water heaters for the Reynolds number range 800-5600. Experiments were conducted in ambient temperatures of 34 to 37 {sup o}C. Data were correlated in the form of Nusselt numbers as: Nu=0.0015 Re{sup 0.75}Pr{sup 1/3} with correlation coefficient of 0.95. Such data can be used to predict heat transfer rates in a polypropylene solar heater in Tehran where the experiments were performed. An application of the results is shown in an example. (author)

  10. 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)

  11. Effect of Filler Orientation on Thermal Conductivity of Polypropylene Matrix Carbon Nanofiber Composites

    Science.gov (United States)

    Enomoto, Kazuki; Fujiwara, Shu; Yasuhara, Toshiyuki; Murakami, Hiroya; Teraki, Junichi; Ohtake, Naoto

    2005-06-01

    Polypropylene matrix carbon nanofiber composites were obtained by injection molding after kneading with a batch-type twin-screw kneader. The thermal conductivity of the composites in the thickness direction was evaluated, with particular focus on the effects of carbon nanofiber (CNF) content and filler orientation. The thermal conductivity of the composites increased with increasing CNF content, and was obtained as 3.46 W/(m\\cdotK) when the CNF content was 50% in weight fraction and the CNFs were highly oriented along the measuring direction of thermal conductivity. This value is approximately seventeenfold higher than that of neat polypropylene.

  12. Preparation and Performance of Continuous Glass Fiber Reinforced Polypropylene Composite Honeycomb Sandwich Panels

    Directory of Open Access Journals (Sweden)

    Chen Ke

    2016-01-01

    Full Text Available As the light-weight and high-strength thermoplastic composites, novel honeycomb sandwich panels were discussed in this paper: continuous glass fiber reinforced polypropylene (GF/PP laminated sheets were used as the surface and polypropylene (PP honeycomb was used as the core. The effects of honeycomb core’s height, thickness and aperture on the mechanical properties were analyzed in this paper. The composite honeycomb sandwich panels exhibited excellent bending strength at 37.6MPa and lateral pressure strength at 25.8MPa.

  13. Durable and rechargeable biocidal polypropylene polymers and fibers prepared by using reactive extrusion.

    Science.gov (United States)

    Badrossamay, Mohammad Reza; Sun, Gang

    2009-04-01

    Incorporation of N-halamine precursor onto polypropylene was explored by using a reactive extrusion process. Several cyclic and acyclic halamine precursors were grafted onto polypropylene backbone through a melt free radical graft copolymerization. The structures and morphology of the grafted polymer were characterized with FTIR, and scanning electron microscope. Thermal properties of the polymers were evaluated by differential scanning calorimetry. The halogenated products of the corresponding grafted samples exhibited potent antimicrobial properties against Escherichia coli, and the antimicrobial properties were durable and regenerable. The relationship between effective surface contact and biocidal efficacy are further discussed.

  14. 可吸收胶原蛋白线与丝线编织非吸收线在口腔种植中的应用%Absorbable collagen suture and non-absorbable silk suture in oral implantation

    Institute of Scientific and Technical Information of China (English)

    徐海洋; 徐昊; 张丽; 曲晓欣; 赵保东

    2014-01-01

    背景:胶原蛋白线由动物的胶原蛋白制备而成,由于其具备可降解、无排异、易于制备、使用方便等优点,现在已开始大量使用于临床。  目的:比较胶原蛋白线与丝线编织线对口腔种植手术切口愈合的影响。  方法:100例种植手术患者随机等分为可吸收胶原蛋白线组和丝线编织非吸收性缝线组,分别使用2-0带圆针可吸收胶原蛋白缝合线与4-0带圆针丝线编织非吸收性缝线对伤口进行间断无张力缝合。植入后3,5,7 d观察缝线及伤口愈合情况,植入后第7天拆线,植入后14 d复诊。  结果与结论:可吸收胶原蛋白线组患者切口甲级愈合率明显多于丝线编织非吸收性缝线组(P OBJECTIVE:To evaluate the effects of col agen suture and silk suture in wound healing after oral implant surgery. METHODS:100 patients undergoing oral implantation were randomly assigned into col agen suture group and silk suture group. A 2-0 circular needle with absorbable col agen sutures and a 4-0 circular needle with non-absorbable silk sutures were employed for tension-free suture in the two groups. After 3, 5, 7 days of oral implantation, suture threads and wound healing were observed. The suture was removed at 14 days, and patients were reviewed at 14 days. RESULTS AND CONCLUSION:The wound healing was better in the col agen suture group than the silk suture group at grade I (P<0.05). At 7 days postoperatively, the suture thread was mostly absorbed in the col agen group but not in the silk suture group. In addition, material alba was invisible in the col agen suture group but clear in the silk suture group. These results indicate that the col agen suture is more proper for tension-free suture than the silk suture, which is better matched to the healing time and keeps a better oral environment.

  15. 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.

  16. Relationship between maturation indices and morphology of the midpalatal suture obtained using cone-beam computed tomography images

    Science.gov (United States)

    Jang, Hong-Ik; Kim, Sang-Cheol; Chae, Jong-Moon; Kang, Kyung-Hwa; Cho, Jin-Woo; Chang, Na-Young; Lee, Keun-Young

    2016-01-01

    Objective The purpose of this study was to determine whether predicting maturation of the midpalatal suture is possible by classifying its morphology on cone-beam computed tomography (CBCT) images and to investigate relationships with other developmental age indices. Methods The morphology of the midpalatal suture was assessed by using CBCT images of 99 patients. Axial plane images of the midpalatal suture were classified into five stages according to the classification scheme. To make the assessment more accurate, the morphology and fusion of the midpalatal suture were additionally investigated on coronal cross-sectional planar images and volume-rendered images. Bone age was evaluated using the hand and wrist method (HWM) and cervical vertebrae method (CVM); dental age (Hellman's index), sex, and chronological age were also assessed. To evaluate relationships among variables, Spearman's rho rank test was performed along with crosstabs using contingency coefficients. Results The HWM and CVM showed strong correlations with the maturation stage of the midpalatal suture, while other indices showed relatively weak correlations (p CBCT stage; the HWM demonstrated slightly higher values (p < 0.0001). Based on the HWM, the midpalatal suture was not fused until stage 6 in both sexes. Conclusions Among developmental age indices, the HWM and CVM showed strong correlations and high associations, suggesting that they can be useful in assessing maturation of the midpalatal suture. PMID:27896208

  17. Comparison of antibacterial-coated and non-coated suture material in intraoral surgery by isolation of adherent bacteria

    Directory of Open Access Journals (Sweden)

    Klaus Pelz

    2015-09-01

    Full Text Available Objectives. In general surgery the incidence of postoperative wound infections is reported to be lower using triclosan-coated sutures. In intraoral surgery, sutures are faced with different bacterial species and the question arises whether the antibacterial-coated suture material has the same positive effects. Materials and Methods. Triclosan-coated and uncoated suture materials were applied in 17 patients undergoing wisdom tooth extraction. Postoperatively, sutures were removed and adherent bacteria were isolated, colony-forming units (cfu were counted, and species identified. Results. Oral bacteria were found in high numbers (cfu>10[sup]7[/sup] on both Vicryl and the triclosan-coated Vicryl Plus. The total number of bacteria isolated from Vicryl Plus was 37% higher than for Vicryl, mainly due to increased numbers of anaerobes. The number of bacterial strains identified was higher for Vicryl ( n=203 than for Vicryl Plus (n=198, but the number of pathogens was higher on Vicryl Plus (n=100 than on Vicryl (n=97. Fewer Gram-positive strains were found on Vicryl Plus (n=95 than on Vicryl (n=107 and, conversely, more Gram-negative strains on Vicryl Plus (103vs.96. Conclusions. In terms of the total number of oral bacteria, and especially oral pathogens, that adhered to suture material, no reduction was demonstrated for Vicryl Plus. The use of triclosan-coated suture material offers no advantage in intraoral surgery.

  18. Efeitos cardiovasculares e midriáticos da fenilefrina tópica a 2,5 e a 10,0% em voluntários sadios Cardiovascular and pupillary effects of topical ophthalmic 2.5 and 10.0% phenylephrine in healthy volunteers

    Directory of Open Access Journals (Sweden)

    Alberto Diniz Filho

    2007-12-01

    Full Text Available OBJETIVO: Comparar os efeitos cardiovasculares e midriáticos da fenilefrina tópica nas concentrações de 2,5 e 10,0%. MÉTODOS: Ensaio clínico do tipo caso controle, randomizado, com auto-emparelhamento. Foram monitoradas a freqüência cardíaca (FC, a pressão arterial (PA e a midríase em voluntários sadios, com idade entre 18 e 45 anos, após a instilação da fenilefrina a 2,5 e a 10,0% em duas ocasiões diferentes. RESULTADOS: A amostra foi constituída de 28 voluntários, sendo 17 do sexo masculino e 11 do sexo feminino, com a idade média de 26,5 anos. Não foi verificado nenhum padrão de mudanças com relação à freqüência cardíaca e à pressão arterial sistólica. Com relação à pressão arterial diastólica média dos indivíduos, não foi encontrada variação significativa após a instilação da fenilefrina a 2,5% nos tempos de um, cinco, dez e 30 minutos, o que se revelou bem diferente quando do uso da fenilefrina a 10,0%, com a qual houve aumento da pressão arterial diastólica média após cinco e dez minutos, e subseqüente queda após 30 minutos, porém sem significância estatística. A midríase foi maior com a fenilefrina a 10,0% nos dois olhos, sendo a diferença estatisticamente significativa. CONCLUSÕES: Observou-se maior efeito midriático da fenilefrina a 10,0%, quando comparada a 2,5%, com significância estatística. Já com relação aos efeitos cardiovasculares não houve diferença estatística entre as duas concentrações.PURPOSE: To compare the cardiovascular and mydriatic effects of 2.5% and 10.0% phenylephrine. METHODS: A case-control, randomized, crossover clinical trial study. We monitored heart rate (HR, blood pressure (BP and mydriasis in healthy volunteers aged 18-45 years after the instillation of 2.5% and 10.0% phenylephrine in two different occasions. RESULTS: The sample comprised 28 healthy volunteers, 17 male and 11 female, with a mean age of 26.5 years. No changes in heart rate and

  19. Microwave ablation at 10.0 GHz achieves comparable ablation zones to 1.9 GHz in ex vivo bovine liver.

    Science.gov (United States)

    Luyen, Hung; Gao, Fuqiang; Hagness, Susan C; Behdad, Nader

    2014-06-01

    We demonstrate the feasibility of using high-frequency microwaves for tissue ablation by comparing the performance of a 10 GHz microwave ablation system with that of a 1.9 GHz system. Two sets of floating sleeve dipole antennas operating at these frequencies were designed and fabricated for use in ex vivo experiments with bovine livers. Combined electromagnetic and transient thermal simulations were conducted to analyze the performance of these antennas. Subsequently, a total of 16 ablation experiments (eight at 1.9 GHz and eight at 10.0 GHz) were conducted at a power level of 42 W for either 5 or 10 min. In all cases, the 1.9 and 10 GHz experiments resulted in comparable ablation zone dimensions. Temperature monitoring probes revealed faster heating rates in the immediate vicinity of the 10.0 GHz antenna compared to the 1.9 GHz antenna, along with a slightly delayed onset of heating farther from the 10 GHz antenna, suggesting that heat conduction plays a greater role at higher microwave frequencies in achieving a comparably sized ablation zone. The results obtained from these experiments agree very well with the combined electromagnetic/thermal simulation results. These simulations and experiments show that using lower frequency microwaves does not offer any significant advantages, in terms of the achievable ablation zones, over using higher frequency microwaves. Indeed, it is demonstrated that high-frequency microwave antennas may be used to create reasonably large ablation zones. Higher frequencies offer the advantage of smaller antenna size, which is expected to lead to less invasive interstitial devices and may possibly lead to the development of more compact multielement arrays with heating properties not available from single-element antennas.

  20. Randomized comparison of polyglycolic acid and polyglyconate sutures for abdominal fascial closure after laparotomy in patients with suspected impaired wound healing

    DEFF Research Database (Denmark)

    Osther, P J; Gjøde, P; Mortensen, Sophie Berit Bondegaard

    1995-01-01

    A randomized study of abdominal fascial closure using interrupted polyglyconate and polyglycolic acid sutures after laparotomy was carried out in 204 consecutive patients with suspected impaired wound healing. There were no statistically significant differences between the two sutures with regard...... to the development of fascial disruption and incisional hernia. Wound infection demanding surgical intervention was found in 7 per cent of patients with polyglyconate sutures and in 16 per cent of those with polyglycolic acid sutures (P = 0.04). Monofilament polyglyconate suture does not reduce the incidence...

  1. 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

    ência 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

  2. Microstructure of a cement matrix composite reinforced with polypropylene fibers

    Directory of Open Access Journals (Sweden)

    Rincón, J. M.

    2004-06-01

    Full Text Available The present investigation deals with the microstructural characterization of a composite material, which is comprised of polypropylene fibers in an cement matrix, by means of environmental scanning electron microscopy (ESEM and field emission scanning electron microscopy (FESEM. The microstructure of the different phases that compose the matrix is very heterogeneous, though there is a uniform distribution of the fibers inside it. The surface of this composite is different after setting, cured and hardening depending if the zone is or not in touch with the walls of the mould. The interface between the different crystalline regions of the cement matrix and the dispersed fibers shows compatibility between the matrix and the polymeric fibers. The mechanical properties (compression and bending strength have also been evaluated. The use of melamine formaldehyde as additive leads to a reinforcement of the cement matrix and to the improvement of the mechanical properties.

    Se ha llevado a cabo una observacíón microestructural detallada de un material compuesto de fibras de polipropileno embebidas en una matriz de cemento usando los nuevos tipos de microscopía electrónica de barrido, tales como: un microscopio electrónico medioambiental (acrónimo en inglés: ESEM y uno de emisión de campo (acrónimo en inglés: FESEM. La microestructura de las diferentes fases que componen la matriz es muy heterogénea, aunque hay una distribución uniforme de las fibras dentro de ellas. La superficie de este material compuesto es diferente después del fraguado, curado y endurecimiento según qué zonas estén o no en contacto con las paredes del molde. La interfase entre las diferentes fases cristalinas de la matriz de cemento y las fibras dispersadas se ha observado a diferentes aumentos, comprobándose compatibilidad entre la matriz y las fibras poliméricas. Las propiedades de resistencia mecánica (tanto a flexión como a compresión han sido tambi

  3. Chondrocyte behavior on nanostructured micropillar polypropylene and polystyrene surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Prittinen, Juha [Department of Applied Physics, University of Eastern Finland, Kuopio (Finland); Jiang, Yu [Department of Chemistry, University of Eastern Finland, Joensuu (Finland); Ylärinne, Janne H. [Department of Applied Physics, University of Eastern Finland, Kuopio (Finland); Pakkanen, Tapani A. [Department of Chemistry, University of Eastern Finland, Joensuu (Finland); Lammi, Mikko J., E-mail: mikko.lammi@uef.fi [Department of Applied Physics, University of Eastern Finland, Kuopio (Finland); Qu, Chengjuan [Department of Applied Physics, University of Eastern Finland, Kuopio (Finland)

    2014-10-01

    This study was aimed to investigate whether patterned polypropylene (PP) or polystyrene (PS) could enhance the chondrocytes' extracellular matrix (ECM) production and phenotype maintenance. Bovine primary chondrocytes were cultured on smooth PP and PS, as well as on nanostructured micropillar PP (patterned PP) and PS (patterned PS) for 2 weeks. Subsequently, the samples were collected for fluorescein diacetate-based cell viability tests, for immunocytochemical assays of types I and II collagen, actin and vinculin, for scanning electronic microscopic analysis of cell morphology and distribution, and for gene expression assays of Sox9, aggrecan, procollagen α{sub 1}(II), procollagen α{sub 1}(X), and procollagen α{sub 2}(I) using quantitative RT-PCR assays. After two weeks of culture, the bovine primary chondrocytes had attached on both patterned PP and PS, while practically no adhesion was observed on smooth PP. However, the best adhesion of the cells was on smooth PS. The cells, which attached on patterned PP and PS surfaces synthesized types I and II collagen. The chondrocytes' morphology was extended, and an abundant ECM network formed around the attached chondrocytes on both patterned PP and PS. Upon passaging, no significant differences on the chondrocyte-specific gene expression were observed, although the highest expression level of aggrecan was observed on the patterned PS in passage 1 chondrocytes, and the expression level of procollagen α{sub 1}(II) appeared to decrease in passaged chondrocytes. However, the expressions of procollagen α{sub 2}(I) were increased in all passaged cell cultures. In conclusion, the bovine primary chondrocytes could be grown on patterned PS and PP surfaces, and they produced extracellular matrix network around the adhered cells. However, neither the patterned PS nor PP could prevent the dedifferentiation of chondrocytes. - Highlights: • Methods to avoid chondrocyte dedifferentiation would be useful for cartilage

  4. Properties of isotactic polypropylene irradiated in various atmospheres

    Directory of Open Access Journals (Sweden)

    Miličević Dejan S.

    2010-01-01

    Full Text Available In this paper, changes in structure and physical properties of stabilized isotactic polypropylene (iPP were created by gamma irradiation, up to a dose of 700 kGy, in different media: air, deionized distilled (DD water and acetylene. Two main effects occur when polyolefins, such as iPP, are subjected to ionizing radiation: crosslinking and scission of macromolecules. The domination of one or the other of these competitive processes is determined by both the structural peculiarities of the polymers and the experimental irradiation conditions. Gel and infrared (IR spectroscopy measurements were used to determine the changes in the degree of network formation and oxidative degradation, respectively. Sol-gel analysis was studied in detail using the Charlesby-Pinner (C-P equation. The radiation-induced changes in the structure and evolution of oxygen-containing species were also studied through dielectric loss (tan δ analysis in a wide temperature and/or frequency range. Evolution of low temperature dielectric relaxations with gamma irradiation was investigated. The results showed that degradation was the major reaction in the initial step of irradiation, no matter what the atmosphere was. The C-P equation seemed applicable when stabilized iPP was irradiated within a certain dose range in various atmospheres. The iPP irradiated in acetylene/air had the lowest/highest values for oxidation level, dielectric losses, Dg and G(s/G(x values. The calculated Dg values are 1.5 and 5 times larger for the irradiation in DD water and air than for the acetylene. Furthermore, our data confirm that oxidation strongly affects the gel point but has a much lower effect on the G(S/G(X ratio. In the case of dielectric relaxation measurements, the connection between the oxidative degradation and dielectric properties is well established and is in good agreement with IR spectroscopy measurements. The amount of carbonyl, hydroperoxide and other polar groups is much higher

  5. The potential of photoacoustic microscopy as a tool to characterize the in vivo degradation of surgical sutures.

    Science.gov (United States)

    Aguirre, Juan; Morales-Dalmau, Jordi; Funk, Lutz; Jara, Francesc; Turon, Pau; Durduran, Turgut

    2014-08-01

    The ex vivo and in vivo imaging, and quantitative characterization of the degradation of surgical sutures (∼500 μm diameter) up to ∼1cm depth is demonstrated using a custom dark-field photo-acoustic microscope (PAM). A practical algorithm is developed to accurately measure the suture diameter during the degradation process. The results from tissue simulating phantoms and mice are compared to ex vivo measurements with an optical microscope demonstrating that PAM has a great deal of potential to characterize the degradation process of surgical sutures. The implications of this work for industrial applications are discussed.

  6. Surgical staples compared with subcuticular suture for skin closure after cesarean delivery: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Sahar Assadi

    2016-03-01

    Full Text Available Background: Cesarean delivery is the most common surgical procedure and this prevalence is on the rise. Given these trends, cesarean wound complications, such as disruption or infection, remain an important cause of post-cesarean morbidity. Methods: We conducted a single-center randomized controlled trial that included women with viable pregnancies (≥24 weeks undergoing cesarean delivery at Motahary University Hospital, Urmia, Iran from April to November 2014. All cesarean types were included: scheduled or unscheduled and primary or repeat cesareans. Women were excluded for the following reasons: inability to obtain informed consent, immune compromising disease (e.g. AIDS, chronic steroid use, diabetic mellitus and BMI≥30. Of 266 women, 133 were randomized to staples and 133 women to suture group. Results: The mean±SD age of the staples group was 27.6±5.4 years and mean±SD age of suture was 28.7±5.9 years. Multiparity is the most frequent in both groups that by using Chi-square test, no significant differences were observed between the two groups (P=0.393. The most frequent indication for cesarean section in both groups was history of cesarean section in staple 40 cases (30.1% and suture 32 cases (24.1%. The survey was conducted using the Chi-square test was not significant (P=0.381. Pain at 6 weeks postoperatively was significantly less in the staple group (P=0.001. Operative time was longer with suture closure (4.68±0.67 versus 1.03±0.07 minute, P<0.001. The Vancouver scale score was significantly less in suture closure (6.6±0.8 versus 7.5±0.9, P=0.001. Wound disruption was significantly less in suture closure (3.8% versus 11.3%, P=0.017. Conclusion: The staple group had low pain and operation time but had a significant wound disruption and scar. The patients who have suffered a significant wound disruption were affected by age (P=0.022 and BMI (P=0.001 at compared those who were not affected by factors such as age or high BMI as

  7. Properties and Semicrystalline Structure Evolution of Polypropylene/Montmorillonite Nanocomposites under Mechanical Load

    DEFF Research Database (Denmark)

    Stribeck, Norbert; Zeinolebadi, Ahmad; Ganjaee Sari, Morteza;

    2012-01-01

    Small-angle X-ray scattering (SAXS) monitors tensile and load-cycling tests of metallocene isotactic polypropylene (PP), a blend of PP and montmorillonite (MMT), and two block copolymer compatibilized PP/MMT nanocomposites. Mechanical properties of the materials are similar, but the semicrystalline...

  8. Histological assessment of titanium and polypropylene fiber mesh implantation with and without fibrin tissue glue

    NARCIS (Netherlands)

    Hallers, E.J.O. ten; Jansen, J.A.; Marres, H.A.M.; Rakhorst, G.; Verkerke, G.J.

    2007-01-01

    Polypropylene (PP) and titanium (Ti) meshes are well-known surgical implants that provoke a relative low foreign body reaction. Firm stabilization of the implant is important to prevent migration and subsequent failure of the operation. Fibrin tissue glues are commercially available adhesives and ar

  9. Effect of pimelic acid on the crystallization, morphology and mechanical properties of polypropylene/wollastonite composites

    Energy Technology Data Exchange (ETDEWEB)

    Meng Mingrui [Department of Polymer Science, College of Materials Science and Engineering, Nangjing University of Technology, Nanjing, Jiangsu Province 210009 (China)], E-mail: mmrstrom@gmail.com; Dou Qiang [Department of Polymer Science, College of Materials Science and Engineering, Nangjing University of Technology, Nanjing, Jiangsu Province 210009 (China)], E-mail: douqiang.njut@163.com

    2008-09-25

    The pimelic acid (PA) was used as a new surface modifier for wollastonite. The effects of PA treatment on the crystallization, morphology and mechanical properties of polypropylene/wollastonite composites were investigated. The Fourier transform infrared spectroscopy analysis revealed that the PA bonded to the wollastonite's surface and formed the calcium pimelate after reacting with the wollastonite. The results of wide angle X-ray diffraction, differential scanning calorimetry and polarized light microscopy proved that the PA treated wollastonite induced more {beta}-crystalline form and decreased the spherulites sizes of polypropylene. The results of scanning electron microscopy showed that the PA treatment enhanced the interfacial adhesion between the filler and the matrix, indicating the improvement of the compatibility between polypropylene and wollastonite. The toughness of the composites was improved by the more ductile {beta}-form spherulites. When 2.5 wt% of PA treated wollastonite was added, the Izod notched impact strength reached its maximum, a value of 17.33 kJ/m{sup 2}, which was 3.19 times greater than that of the blank polypropylene.

  10. Electron beam irradiation conditions and foam seat properties in polypropylene-polyethylene blends

    Science.gov (United States)

    Tokuda, S.; Kemmotsu, T.

    1995-02-01

    High expansion polypropylene foam (20-100kg/m 3) is industrially produced by blending polypropylene with thermal decomposition foaming agent, which is then irradiated with electron beam to induce crosslinking, and is finally heated, causing the foaming agent to decompose and generate foams. Here, crosslinking stage also serves to increase the melt viscosity of the mixture so that an appropriate value is obtained for foaming. In order to obtain desirable final product, the important factors in the above process are the material properties of the polypropylene and the appropriate control of crosslinking, which is governed by the selection of crosslinking-promoter and the irradiation conditions. We have used polypropylene random copolymer (R-PP) with low ethylene content and performed studies on the relation between the amount of electron beam irradiation and the degree of crosslinking and also on the effect of the multifunctional monomers as crosslinking-promoter. We have also produced foams using blends of this R-PP and linear low density polyethylene (L-LDPE) and evaluated their mechanical properties and their heat resistance.

  11. Reinforcement of polypropylene by annual plant fibers: optimisation of the coupling agent efficiency

    NARCIS (Netherlands)

    Snijder, M.H.B.; Bos, H.L.

    2000-01-01

    Annual growth agrofibers like flax and jute can compete with glass fibers, considering their intrinsic mechanical properties. This paper discusses reinforcement of polypropylene (PP) homopolymer with flax bast fibers. Maleic Anhydride modified PP (MAPP) grades are screened on coupling efficiency. Th

  12. A Comprehensive Study of the Polypropylene Fiber Reinforced Fly Ash Based Geopolymer

    DEFF Research Database (Denmark)

    Ranjbar, Navid; Mehrali, Mehdi; Behnia, Arash;

    2016-01-01

    and long term impacts of different volume percentages of polypropylene fiber (PPF) reinforcement on fly ash based geopolymer composites. Different characteristics of the composite were compared at fresh state by flow measurement and hardened state by variation of shrinkage over time to assess the response...

  13. Preparation and thermal behaviour of a series of liquid wood-polypropylene composites

    Science.gov (United States)

    Blanco, Ignazio; Cicala, Gianluca; Latteri, Alberta; Saccullo, Giuseppe

    2016-05-01

    Liquid Wood (a mixture of cellulose, hemp, fax and lignin) was used to prepare, by mechanical mixing followed by thermal extrusion, blends of various Polypropylene (PP)/Liquid Wood ratios. To verify if and how much the composition of the obtained composites affects their thermal properties Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) experiments were carried out.

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

    Energy Technology Data Exchange (ETDEWEB)

    Adem, E. [Instituto de Fisica UNAM, A. Postal 20-364, Mexico DF, 01000 (Mexico)]. E-mail: esbaide@fisica.unam.mx; Burillo, G. [Instituto de Ciencias Nucleares UNAM, Mexico, DF, 01000 (Mexico); Avalos-Borja, M. [Centro de Ciencias de la Materia Condensada, UNAM. A. Postal 2681, Ensenada, BC, 22800 (Mexico); Carreon, Ma.P. [Instituto de Ciencias Nucleares UNAM, Mexico, DF, 01000 (Mexico)

    2005-07-01

    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.

  15. 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%...

  16. Jute fiber reinforced polypropylene produced by continuous extrusion compounding. Part 1. Processing and ageing properties

    NARCIS (Netherlands)

    Oever, van den M.J.A.; Snijder, M.H.B.

    2008-01-01

    This article addresses the processing and ageing properties of jute fiber reinforced polypropylene (PP) composites. The composite has been manufactured by a continuous extrusion process and results in free flowing composite granules, comprising up to 50 weight percent (wt %) jute fiber in PP. These

  17. BEHAVIOR OF CHO CELLS ON MODIFIED POLYPROPYLENE BY LOW TEMPERATURE AMMONIA PLASMA

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong; YU Yaoting; PAN Jilun; XU Yuanping; ZHU Hesun

    2001-01-01

    The surface of polypropylene (PP) membrane was modified by low temperature plasma with ammonia. The effect of exposure time was investigated by means of contact angle measurement. The results show that low temperature ammonia plcsma treatment can enhance its hydrophilicity. Chinese hamster ovary (CHO) cells attachment on the modified membrane was enhanced and the growth rate on the membrane was faster than unmodified one.

  18. Oriented crystallization and mechanical properties of polypropylene nucleated on fibrillated polytetrafluoroethylene scaffolds

    NARCIS (Netherlands)

    Meer, van der Douwe W.; Milazzo, Daniel; Sanguineti, Aldo; Vancso, G. Julius

    2005-01-01

    It is known that friction deposited polytetrafluoroethylene (PTFE) layers are able to nucleate crystallization of thin films of isotactic polypropylene (iPP). In order to investigate the influence of PTFE on the crystallization behavior and morphology of iPP in bulk, PTFE-particles of two different

  19. Ag2S deposited on oxidized polypropylene as composite material for solar light absorption

    NARCIS (Netherlands)

    Krylovaa, V.; Milbrat, A.; Embrachts, A.; Baltrusaitis, J.

    2014-01-01

    Thin film metal chalcogenides are superior solar light absorbers and can be combined into a functional material when deposited on polymeric substrates. Ag2S composite materials were synthesized on oxidized polypropylene using chemical bath deposition method and their properties were explored using X

  20. Repair of large midline incisional hernias with polypropylene mesh: comparison of three operative techniques.

    NARCIS (Netherlands)

    Vries Reilingh, T.S. de; Geldere, D. van; Langenhorst, B.; Jong, D. de; Wilt, G.J. van der; Goor, H. van; Bleichrodt, R.P.

    2004-01-01

    Polypropylene mesh is widely used for the reconstruction of incisional hernias that cannot be closed primarily. Several techniques have been advocated to implant the mesh. The objective of this study was to evaluate, retrospectively, early and late results of three different techniques, onlay, inlay

  1. A novel approach in organic waste utilization through biochar addition in wood/polypropylene composites

    Energy Technology Data Exchange (ETDEWEB)

    Das, Oisik [Department of Civil and Environmental Engineering, University of Auckland, Auckland 1142 (New Zealand); Sarmah, Ajit K., E-mail: a.sarmah@auckland.ac.nz [Department of Civil and Environmental Engineering, University of Auckland, Auckland 1142 (New Zealand); Bhattacharyya, Debes [Department of Mechanical Engineering, Center for Advanced Composite Materials, University of Auckland, Auckland 1142 (New Zealand)

    2015-04-15

    Highlights: • Biochar made from waste wood was added with wood polypropylene composites. • 24% biochar gave the best mechanical properties. • 6% biochar had no effect on physico-mechanical properties of composites. • Coupling agent remained unreacted in composites having higher amount of biochar. - Abstract: In an attempt to concurrently address the issues related to landfill gas emission and utilization of organic wastes, a relatively novel idea is introduced to develop biocomposites where biochar made from pyrolysis of waste wood (Pinus radiata) is added with the same wood, plastic/polymer (polypropylene) and maleated anhydride polypropylene (MAPP). Experiments were conducted by manufacturing wood and polypropylene composites (WPCs) mixed with 6 wt%, 12 wt%, 18 wt%, 24 wt%, and 30 wt% biochar. Though 6 wt% addition had similar properties to that of the control (composite without biochar), increasing biochar content to 24 wt% improved the composite’s tensile/flexural strengths and moduli. The biochar, having high surface area due to fine particles and being highly carbonised, acted as reinforcing filler in the biocomposite. Composites having 12 wt% and 18 wt% of biochar were found to be the most ductile and thermally stable, respectively. This study demonstrates that, WPCs added with biochar has good potential to mitigate wastes while simultaneously producing biocomposites having properties that might be suited for various end applications.

  2. Protein repellent hydrophilic grafts prepared by surface-initiated atom transfer radical polymerization from polypropylene

    DEFF Research Database (Denmark)

    Fristrup, Charlotte Juel; Jankova Atanasova, Katja; Eskimergen, Rüya

    2012-01-01

    Grafting of poly(ethylene glycol)methacrylate (PEGMA) and N,N-dimethylacrylamide (DMAAm) from UV-initiator modified polypropylene (PP) was performed by Surface-Initiated Atom Transfer Radical Polymerization (SI-ATRP). The modification and hydrophilization of the PP substrates were confirmed...

  3. Superhydrophobic Properties of Nanotextured Polypropylene Foils Fabricated by Roll-to-Roll Extrusion Coating

    DEFF Research Database (Denmark)

    Telecka, Agnieszka; Murthy, Swathi; Sun, Ling

    2016-01-01

    We demonstrate the use of roll-to-roll extrusion coating (R2R-EC) for fabrication of nanopatterned polypropylene (PP) foils with strong antiwetting properties. The antiwetting nanopattern is originated from textured surfaces fabricated on silicon wafers by a single-step method of reactive ion...

  4. Effect of Multiple Extrusions on the Impact Properties of Polypropylene/Clay Nanocomposites

    DEFF Research Database (Denmark)

    Klitkou, Rasmus; Jensen, Erik Appel; Christiansen, Jesper de Claville

    2012-01-01

    Polypropylene (PP)-based polymer nanocomposites containing organically modified montmorillonite (OMMT) with and without maleic anhydride grafted PP, were compounded by twin-screw extrusion. The extrusion process was repeated various numbers of times to increase the extruder residence time (TR) and...

  5. Comparative evaluation of sutures coated with triclosan and chlorhexidine for oral biofilm inhibition potential and antimicrobial activity against periodontal pathogens: An in vitro study

    Directory of Open Access Journals (Sweden)

    Kunal Sunder Sethi

    2016-01-01

    Full Text Available Background: Surgical site plaque accumulation is one of the challenging problems leading to unfavorable healing. The antibacterial sutures can be used to reduce or inhibit plaque formation. Presently there is no study comparing efficacy of sutures coated with triclosan and chlorhexidine in terms of oral biofilm inhibition and antimicrobial property against periodontal pathogens. Aim: The aim of present study was to evaluate the antibacterial efficacy and oral biofilm inhibition around chlorhexidine and triclosan coated polyglactin sutures in comparison to uncoated sutures. Materials and Method: Equal segments of chlorhexidine and triclosan coated polyglactin sutures (3-0 were incubated at 370°C in saliva collected from 10 chronic periodontitis patients for 7 days. Plain uncoated suture served as control. Biofilm formation was analyzed with Confocal Laser-Scanning Microscopy (CLSM and Scanning Electron Microscopy (SEM. Quantitative assessment was done using Colony Forming Units (CFU/mL.The antibacterial efficacy of the sutures was tested against specific periodontal pathogens (S.mutans, F.nucleatum, A.actinomycetomcomitans, P.intermedia, P.gingivalis using agar diffusion method. CLSM and SEM were not subjected to statistical analysis. ANOVA test was used for colony forming units and agar diffusion test. (P < 0.05 Results: CLSM and SEM showed substantial biofilm inhibition around chlorhexidine-coated sutures followed by triclosan-coated when compared to plain uncoated suture. The antibacterial coated sutures showed statistically significant difference in CFUs/ml and zone of inhibition compared to plain uncoated sutures. Among coated sutures, chlorhexidine-coated sutures showed better results. Conclusion: The antibacterial coated sutures have a promising potential in preventing the colonization of periodontal pathogens around it thereby inhibiting biofilm formation.

  6. Suturing property of tough double network hydrogels for bio-repair materials

    Science.gov (United States)

    Na, Yang Ho; Oh, Hwa Yeon; Ahn, Young Ju; Han, Youngbae

    2015-02-01

    Cartilage and meniscal lesions have limited potential for spontaneous repair. Consequently, much effort has been made to develop methods for repairing such lesions. Double-network (DN) gels are new candidate-materials for repairing such lesions. They exhibit exceptional mechanical strength and toughness in spite of their high water content. In this study, we prepared highly tough DN hydrogels and investigated the mechanical properties related to clinical implant use. The mechanical properties such as Young's modulus and suture tear-out strength were measured for the artificial replacement. The results suggest that the suture property of DN hydrogels can be adjusted by controlling the crosslinking density and monomer concentration. Finite element method was also applied to these DN hydrogels in order to check whether the fracture strength of the material is enough to meet a medical purpose.

  7. Ultrasound biomicroscopy confirmation of corneal overriding due to improper suturing of full-thickness corneal laceration

    Directory of Open Access Journals (Sweden)

    Murat Kucukevcilioglu

    2014-12-01

    Full Text Available We herein present a case with corneal overriding due to improper suturing of a full-thickness corneal laceration. There was a 2.5-mm difference between horizontal and vertical white-to-white measurements in the cornea. However, slit lamp examination failed to demonstrate the exact architecture of the laceration. Ultrasound biomicroscopy defined the wound edges thoroughly and confirmed the presence of corneal overriding. Six weeks after suture enhancement, the abnormal oval appearance of the cornea was absent and correct apposition of the corneal edges was seen on ultrasound biomicroscopy. Ultrasound biomicroscopy can be used in preoperative surgical planning of cases with complicated corneal lacerations. It can be used to adjust and enhance wound architecture in eyes with penetrating injury.

  8. Crustal architecture and tectonic evolution of the Cauvery Suture Zone, southern India

    Science.gov (United States)

    Chetty, T. R. K.; Yellappa, T.; Santosh, M.

    2016-11-01

    The Cauvery suture zone (CSZ) in southern India has witnessed multiple deformations associated with multiple subduction-collision history, with incorporation of the related accretionary belts sequentially into the southern continental margin of the Archaean Dharwar craton since Neoarchean to Neoproterozoic. The accreted tectonic elements include suprasubduction complexes of arc magmatic sequences, high-grade supracrustals, thrust duplexes, ophiolites, and younger intrusions that are dispersed along the suture. The intra-oceanic Neoarchean-Neoproterozoic arc assemblages are well exposed in the form of tectonic mélanges dominantly towards the eastern sector of the CSZ and are typically subjected to complex and multiple deformation events. Multi-scale analysis of structural elements with detailed geological mapping of the sub-regions and their structural cross sections, geochemical and geochronological data and integrated geophysical observations suggest that the CSZ is an important zone that preserves the imprints of multiple cycles of Precambrian plate tectonic regimes.

  9. Rejuvenation of Fossil Sutures and Related Mesozoic Intracontinental Orogenies in South China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The Huanan (South China) subcontinent was created by amalgamation of the Yangtze, Xianggan, Cathaysia and Zhemin microcontinents by the Guangxi orogeny in the Early Palaeozoic. The closure of the Tethyan Ocean and subsequent collision event outside the amalgamated continent reactivated fossil sutures and resulted in intracontinental (ensialic) orogenies in the Mesozoic. Based on evidence from deformation, molasse and granitoids, the Sichuan-Guizhou-Hunan-southern Hubei and Hunan-Jiangxi-Fujian Yanshanian fold-thrust systems and the Lower Yangtze-northwestern Fujian Indosinian fold-thrust system are thought to be intracontinental orogens. Their main features are as follows: intracontinental orogenies occurred areally, thrusting propagated towards the interior of the continental, they extend parallelly to the strikes of the fossil sutures, and the details of the temporal-spatial evolution of the orogens depend on subduction-collision events.

  10. 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.

  11. Using sutures to attach miniature tracking tags to small bats for multimonth movement and behavioral studies

    Science.gov (United States)

    Castle, Kevin T.; Weller, Theodore J.; Cryan, Paul M.; Hein, Cris D.; Schirmacher, Michael R.

    2015-01-01

    1. Determining the detailed movements of individual animals often requires them to carry tracking devices, but tracking broad-scale movement of small bats (brown bats (Eptesicus fuscus) in Colorado and hoary bats (Lasiurus cinereus) in California. 3. GPS tags and data loggers were sutured to 17 bats in this study. Three tagged bats were recaptured seven months after initial deployment, with tags still attached; none of these bats showed ill effects from the tag. No severe injuries were apparent upon recapture of 6 additional bats that carried tags up to 26 days after attachment, however one of the bats exhibited skin chafing. 4. Use of absorbable sutures to affix small tracking devices seems to be a safe, effective method for studying movements of bats over multiple months, although additional testing is warranted. This new attachment method has the potential to quickly advance our understanding of small bats, particularly as more-sophisticated miniature tracking devices (e.g., satellite tags) become available.

  12. Calvarial and sutural re-development following craniectomy in the neonatal rabbit.

    Science.gov (United States)

    Mabbutt, L W; Kokich, V G

    1979-01-01

    In the present investigation extensive calvariectomy was performed on neonatal rabbits and the subsequent regeneration of the calvarium was followed grossly, radiographically and histologically. The results indicate that regeneration of the calvarium is a gradual process which exhibits a definite pattern and rate. Furthermore, although the sutural articulations re-develop in their proper anatomical positions and exhibit normal histological structure, they tend to synostose earlier than controls. Of perhaps greater biological significance is the apparent importance of the periosteal envelope during the regenerative process. Maintenance of dural integrity during operation, and the re-establishment of pericranial continuity post-operatively, seem to be essential for restoration of normal sutural and skeletal architecture. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 PMID:500496

  13. The influence of stenosis degrees and graft suture position on local hemodynamics of coronary bypass

    Science.gov (United States)

    Totorean, A. F.; Bernad, S. I.; Susan-Resiga, R. F.

    2016-06-01

    Bypass graft failure is mainly caused by intimal hyperplasia (IH) that occurs at the graft anastomosis after coronary artery bypass grafting (CABG) surgery. It has been shown that local hemodynamics influences the process of IH initiation and progression. A main concern at this type of surgery is to increase the graft patency, respectively to improve the local hemodynamics. This paper analyzes the influence of different degree of stenosis severity and graft suture position on graft patency, taking into consideration the local hemodynamics. Bypass configurations with anastomosis angle of 45° were numerically investigated, with respect to wall shear stress and pressure variation. We can assume that in the conditions of our study, different stenosis degrees and position of the graft suture influence the local blood flow conditions, and, nevertheless, the graft patency.

  14. "Nara" knot for suturing of cleft lip in children to make removal easy

    Directory of Open Access Journals (Sweden)

    Obaidullah

    2006-01-01

    Full Text Available Cleft patients usually go through a lifetime of repeated hospital admissions and multiple procedures. Suture removal at a tender age and on a sensitive area like the lip becomes a challenge for the nursing staff. It is also emotionally demanding on the part of the parents. Hence, in most centres these patients are at least sedated if not anaesthetised. We have been using a simple knot and running prolene material so that undoing of the knot becomes easy and suture removal more or less atraumatic. We would like to share our experience with readers through this article. An analysis of 53 cleft lip repairs has shown that this knot is safe and easily removable.

  15. Traumatic lumbar hernia repair: a laparoscopic technique for mesh fixation with an iliac crest suture anchor.

    Science.gov (United States)

    Links, D J R; Berney, C R

    2011-12-01

    Traumatic lumbar hernia (TLH) is a rare presentation. Traditionally, these have been repaired via an open approach. Recurrence can be a problem due to the often limited tissue available for mesh fixation at the inferior aspect of the hernia defect. We report the successful use of bone suture anchors placed in the iliac crest during transperitoneal laparoscopy for mesh fixation to repair a recurrent TLH. This technique may be particularly useful after previous failed attempts at open TLH repair.

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

    Directory of Open Access Journals (Sweden)

    M. Paknejad

    2004-06-01

    Full Text Available 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 referred to Faculty of Dentistry, Tehran University of Medical science. In test group, the gingivalgraft were placed on cellophane and after applying one drop of Eg then placed in the proper position. In control group silk suturing was used.Results: The degree of pain had no significant differences in two groups (P>0.05. The rate of bleeding was insignificant at the first day (P=0.5, but in the second (P=0.0425and the third day (P=0.0313 less bleeding was observed in the test group. 10 days after the surgery, grafts in the test group had better healing (P=0.0425, while 3 month later no significant differences observed (P>0.05. Although the mean tissue shrinkage were 41%and 38% for control and test group respectively, Wilcoxon test showed no significant differences 30 days after surgery (P>0.05. The tissue shrinkage also was not significant 3 months after surgery. In addition, no displacement, infection or hypersensitivity werenoted in either of two groups.Conclusion: In FGG, Epiglu is more effective than suturing.

  17. Elastic suture (shoelace technique) for fasciotomy closure after treatment of compartmental syndrome associated to tibial fracture.

    Science.gov (United States)

    Branco, Paulo Sergio Martins Castelo; Cardoso Junior, Mauricio; Rotbande, Isaac; Ciraudo, José Antonio Fraga; Silva, Celso Ricardo Correa de Melo; Leal, Paulo Cesar Dos Santos

    2017-01-01

    This article reports the use of elastic suture as an adjuvant in surgical wound closure caused by decompressive fasciotomy after compartment syndrome associated with a compound fracture of the tibia. Widely used in other medico-surgical specialties, this technique is unusual in orthopedics surgery, but the simplicity of the procedure and the successful outcome observed in this case allows for its consideration as indicated for situations similar to that presented in this study.

  18. Conduction Disorders in Continuous Versus Interrupted Suturing Technique in Ventricular Septal Defect Surgical Repair

    Directory of Open Access Journals (Sweden)

    Gholampour-Dehaki

    2016-01-01

    Full Text Available Background Ventricular septal defects (VSD is one of the most frequent congenital cardiac malformations and cardiac conduction disorders are still one of the serious postoperative complications in this surgery. Objectives This study aimed to compare the incidence of conduction disorders with the use of continuous compared to interrupted suturing techniques in VSD surgical repair. Patients and Methods Previously recorded data of 231 patients who underwent surgical closure of VSD between January 2009 and January 2012 at the Rajaie cardiovascular medical and research center were retrospectively reviewed. VSD surgical repair was performed using continues suturing technique in group A patients (n = 163, 70.6% and interrupted suturing technique in group B patients (n = 68, 29.4%. Results The most common concomitant congenital anomaly was Tetralogy of Fallot (27.3%. Twenty-four (10.4% patients had intraoperative cardiac arrhythmia, including 19 (8.2% transient and 5 (2.2 % permanent arrhythmia. During their ICU stay, ventricular arrhythmia and complete heart block were observed in 34 (14.7% and 5 patients (2.2%, respectively. At the time of the last follow-up, incomplete right bundle branch block (RBBB, complete RBBB, RBBB with left anterior hemi-block, and complete heart block were identified in 84 (36.4%, 42 (18.2%, 29 (12.6%, and 5 patients (2.2%, respectively. The results revealed that group A patients were most likely to have had cardiac arrhythmias during their ICU stay and at the time of last follow-up (P < 0.001, while the intraoperative incidence of cardiac arrhythmia during surgery was not statistically significant between the two groups (P = 0.06. Conclusions In the absence of any statistical differences in the other risk factors between the two groups, the difference in the incidence of conduction disorders can be attributed to the type of suturing used during the procedure.

  19. LigaSure versus Conventional Suture Ligature for Vaginal Hysterectomy: a Randomized Controlled Trial

    OpenAIRE

    Mohamed Abd Elzaher, a, b, Ashraf Moawad, a, c and Hanaa Abu-Ria

    2011-01-01

    Introduction: Vaginal hysterectomy is considered to be the method of choice for removal of the uterus. Of particular concern for the vaginal surgeon is the ability to access, visualize, and legate structures while maintaining adequate hemostasis. Surgical hemostasis can be secured by a variety of methods, including mechanical means (sutures) or vessel coagulation (diathermy). Electro-surgical vessel sealing (LigaSure) is a new hemostatic system based on the combination of pressure and bipolar...

  20. A novel suture method to place and adjust peripheral nerve catheters

    DEFF Research Database (Denmark)

    Rothe, C.; Steen-Hansen, C.; Madsen, M. H.;

    2015-01-01

    We have developed a peripheral nerve catheter, attached to a needle, which works like an adjustable suture. We used in-plane ultrasound guidance to place 45 catheters close to the femoral, saphenous, sciatic and distal tibial nerves in cadaver legs. We displaced catheters after their initial plac...... successful and 42/43 secondary placements successful by ultrasound, confirmed in 10/10 cases by magnetic resonance imaging....

  1. Mini-plate fixation versus suture suspensory fixation in cervical laminoplasty

    Science.gov (United States)

    Liu, Feng-Yu; Ma, Lei; Huo, Li-Shuang; Cao, Yan-Xiang; Yang, Da-Long; Wang, Hui; Yang, Si-Dong; Ding, Wen-Yuan

    2017-01-01

    Abstract Background: Both the mini-plate fixation and suture suspensory fixation techniques are extensively applied in cervical laminoplasty, but which technique is superior has not been ascertained. The purpose of this meta-analysis is to compare the results between mini-plate fixation and suture suspensory fixation in cervical laminoplasty for the patients with multilevel cervical compressive myelopathy. Methods: PubMed, Embase, the Cochrane library, CNKI, and WANFANG were searched for studies that compared mini-plate fixation and suture suspensory fixation in cervical laminoplasty up to November 1, 2016. We calculated odds ratio (OR) with 95% confidence interval (CI) for dichotomous outcomes and mean difference (MD) with 95% CI for continuous outcomes. Review Manager 5.3 was used for the statistical analyses. Results: A total of 25 studies, involving 1603 participants, were included in this review. The results of this meta-analysis indicated that there were statistically significant differences in postoperative Japanese Orthopedic Association (JOA) scores (MD = 0.67, 95% CI: 0.34–0.99, P statistically significant difference in C5 palsy (OR = 0.82, 95% CI: 0.37–1.84, P = 0.63). Conclusions: As compared with suture suspensory fixation, mini-plate fixation in cervical laminoplasty appears to achieve better clinical and radiographic outcomes with fewer surgical complications. However, mini-plate fixation is associated with bigger surgical trauma. This conclusion should be interpreted cautiously and more high-quality, randomized controlled trials are needed in the future. PMID:28151906

  2. Tracking the Archean-Proterozoic suture zone in the northeastern Great Basin, Nevada and Utah

    Science.gov (United States)

    Rodriguez, B.D.; Williams, J.M.

    2008-01-01

    It is important to know whether major mining districts in north-central Nevada are underlain by crust of the Archean Wyoming craton, known to contain major orogenic gold deposits or, alternatively, by accreted crust of the Paleoproterozoic Mojave province. Determining the location and orientation of the Archean-Proterozoic suture zone between these provinces is also important because it may influence subsequent patterns of sedimentation, deformation, magmatism, and hydrothermal activity. The suture zone is exposed in northeastern Utah and south-western Wyoming and exhibits a southwest strike. In the Great Basin, the suture zone strike is poorly constrained because it is largely concealed below a Neoproterozoic-Paleozoic miogeocline and Cenozoic basin fill. Two-dimensional resistivity modeling of three regional north-south magnetotelluric sounding profiles in western Utah, north-central Nevada, and northeastern Nevada, and one east-west profile in northeastern Nevada, reveals a deeply penetrating (>10 km depth), broad (tens of kilometers) conductor (1-20 ohm-meters) that may be the Archean-Proterozoic suture zone, which formed during Early Proterozoic rifting of the continent and subsequent Proterozoic accretion. This major crustal conductor changes strike direction from southwest in Utah to northwest in eastern Nevada, where it broadens to ???100 km width that correlates with early Paleozoic rifting of the continent. Our results suggest that the major gold belts may be over-isolated blocks of Archean crust, so Phanerozoic mineral deposits in this region may be produced, at least in part, from recycled Archean gold. Future mineral exploration to the east may yield large gold tonnages. ?? 2008 Geological Society of America.

  3. The “excluding” suture technique for surgical closure of ventricular septal defects: A retrospective study comparing the standard technique

    Directory of Open Access Journals (Sweden)

    Roy Varghese

    2016-01-01

    Conclusion: Surgical closure of VSDs can be accomplished by placing sutures along the margins or away with comparable results. The incidence of CHB, however, seems to be less when the “excluding” technique is employed.

  4. Ab-interno scleral suture loop fixation with cow-hitch knot in posterior chamber intraocular lens decentration

    Science.gov (United States)

    Can, Ertuğrul; Koçak, Nurullah; Yücel, Özlem Eşki; Gül, Adem; Öztürk, Hilal Eser; Sayın, Osman

    2016-01-01

    Aim of Study: To describe a simplified ab-interno cow-hitch suture fixation technique for repositioning decentered posterior chamber intraocular lens (PC IOL). Materials and Methods: Two cases are presented with the surgical correction of decentered and subluxated IOL. Ab-interno scleral suture fixation technique with hitch-cow knot in the eye was performed with a ciliary sulcus guide instrument and 1 year follow-up was completed. Results: Both of the patients had well centered lenses postoperatively. Corrected distant and near visual acuities of the patients were improved. There was no significant postoperative complication. In the follow-up period of 1 year, no evidence of suture erosion was found. Conclusions: Ab-interno scleral suture loop fixation with hitch-cow knot in the eye was effective in repositioning decentered or subluxated PC IOLs with excellent postoperative centered lenses and visual outcomes. PMID:27050346

  5. Ab-interno scleral suture loop fixation with cow-hitch knot in posterior chamber intraocular lens decentration

    Directory of Open Access Journals (Sweden)

    Ertugrul Can

    2016-01-01

    Full Text Available Aim of Study: To describe a simplified ab-interno cow-hitch suture fixation technique for repositioning decentered posterior chamber intraocular lens (PC IOL. Materials and Methods: Two cases are presented with the surgical correction of decentered and subluxated IOL. Ab-interno scleral suture fixation technique with hitch-cow knot in the eye was performed with a ciliary sulcus guide instrument and 1 year follow-up was completed. Results: Both of the patients had well centered lenses postoperatively. Corrected distant and near visual acuities of the patients were improved. There was no significant postoperative complication. In the follow-up period of 1 year, no evidence of suture erosion was found. Conclusions: Ab-interno scleral suture loop fixation with hitch-cow knot in the eye was effective in repositioning decentered or subluxated PC IOLs with excellent postoperative centered lenses and visual outcomes.

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

    DEFF Research Database (Denmark)

    Klein, Mads; Pommergaard, Hans-Christian; Gögenur, Ismail;

    2011-01-01

    Anastomotic dehiscence remains an important challenge for colorectal surgeons worldwide. Extensive research focused on performing a safe anastomosis is conducted with rats being the most used model when examining colorectal anastomoses. In daily clinical practice resorbable sutures are used when...

  7. Sulcus vocalis: excision, primary suture and medialization laryngoplasty: personal experience with 44 cases.

    Science.gov (United States)

    Yılmaz, Taner

    2012-11-01

    This is a prospective, cohort study to present personal experience on excision of sulcus, primary suture of defect and medialization laryngoplasty. An article about this subject is not present in medical literature. Forty-four patients with sulcus vocalis who were operated on by excision, primary suture of epithelial defect and medialization laryngoplasty were included. Pre- and postoperative evaluations included GRBAS, VHI-30, stroboscopy, aerodynamic and acoustic analysis. Grade, roughness and breathiness of GRBAS were significantly better postoperatively (p  0.05). All VHI-30 results decreased significantly after surgery (p  0.05). Maximum phonation time, mean airflow rate, mean efficiency and mean pressure of aerodynamic analysis improved significantly after surgery (p  0.05). All parameters, except F (0) and soft phonation index during acoustic analysis with /a/, and except F (0), voice turbulence index and soft phonation index during acoustic analysis with constant phrase improved significantly after surgery (p sulcus vocalis are not satisfactory enough, yet. Excision of sulcus, primary suture of epithelial defect and medialization laryngoplasty is one of the successful surgical options. Intact vocal ligament at the bottom of sulcus is a good prognostic sign for good postoperative voice result. Success appears to depend on how long, how wide and how deep sulcus is. Good patient selection may increase the percentage of happy patients.

  8. Smart tissue anastomosis robot (STAR): a vision-guided robotics system for laparoscopic suturing.

    Science.gov (United States)

    Leonard, Simon; Wu, Kyle L; Kim, Yonjae; Krieger, Axel; Kim, Peter C W

    2014-04-01

    This paper introduces the smart tissue anastomosis robot (STAR). Currently, the STAR is a proof-of-concept for a vision-guided robotic system featuring an actuated laparoscopic suturing tool capable of executing running sutures from image-based commands. The STAR tool is designed around a commercially available laparoscopic suturing tool that is attached to a custom-made motor stage and the STAR supervisory control architecture that enables a surgeon to select and track incisions and the placement of stitches. The STAR supervisory-control interface provides two modes: A manual mode that enables a surgeon to specify the placement of each stitch and an automatic mode that automatically computes equally-spaced stitches based on an incision contour. Our experiments on planar phantoms demonstrate that the STAR in either mode is more accurate, up to four times more consistent and five times faster than surgeons using state-of-the-art robotic surgical system, four times faster than surgeons using manual Endo360(°)®, and nine times faster than surgeons using manual laparoscopic tools.

  9. Adjustable versus non-adjustable suture techniques for concomitant horizontal strabismus: a comparative study

    Directory of Open Access Journals (Sweden)

    Galton C. Vasconcelos

    2015-12-01

    Full Text Available ABSTRACT Purpose: To compare the surgical results of adjustable and non-adjustable horizontal strabismus surgery for concomitant horizontal strabismus. Methods: The charts of 231 patients, who underwent horizontal strabismus surgery, selected using probabilistic sampling, were retrospectively reviewed. Patients were divided into two groups according to the surgical technique used and strabismus type. The adjustable suture technique was used for 107 patients (Group 1, and non-adjustable or conventional surgery was performed in the remaining 124 patients (Group 2. Patients with esotropia (ET or exotropia (XT of 5 PD, syndromes, restrictive or paretic strabismus, reoperations, botulinum toxin injection, and patients postoperatively followed up for 50% was present in all subgroups. Significant differences between strabismus groups submitted to adjustable technique and non-adjustable on postoperative day 1 were observed (p=0.00 for ET and p=0.01 for XT and at the last visit for the XT group with a follow-up of at least 1 year (p=0.05. Conclusion: The adjustable suture technique produced a higher success rate than non-adjustable strabismus surgery for both ET and XT groups on postoperative day 1. For XT patients, the adjustable suture technique appears to produce better surgical results than non-adjustable surgery, when the surgical goal is long-lasting maintenance of a small hypercorrection.

  10. Inferring the viscous and elastic properties of a suture zone in Larsen C

    Science.gov (United States)

    O'Leary, Martin; Kulessa, Bernd; Booth, Adam; Holland, Paul; Jansen, Daniela; King, Ed; Luckman, Adrian; McGrath, Dan; Zwinger, Thomas

    2016-04-01

    After the collapse of its neighbours, Larsen A and B, the Larsen C ice shelf is widely considered at risk of future climate-driven instability. Recent work has shown that the ice shelf is stabilized by soft melange in its suture zones, where adjacent flow units merge. Little is known about the mechanical properties of melange however, so that the quantification of its effect on the stability of Larsen C Ice Shelf has remained challenging. To identify the structural and elastic properties of the Joerg Peninsula suture zone in Larsen C Ice Shelf, we integrate seismic reflection and ground-penetrating radar (GPR) geophysical measurements. GPR transects reveal the presence of a stiff layer of meteoric ice, trapped between the softer melange beneath and the firn layer above. Monte Carlo analysis reveals that the seismic velocity of this melange is noticeably reduced compared to meteoric ice. By applying Hashin-Shtrikman bounds on the elastic moduli of a two-phase mixture of ice and water to the velocities, we are able to derive the elastic properties of the melange. We ascertain, significantly, that the melange is softer than meteoric ice because it contains a substantial volume fraction of water. The meteoric ice layer is buckling due to compressive lateral stresses. We suggest this process is analogous to fold buckling in sedimentary rocks. Using the ice flow model Elmer/Ice we are able to replicate this process, and thereby derive bounds on the rheological properties of the suture zone melange.

  11. Modality of wound closure after total knee replacement: are staples as safe as sutures? A retrospective study of 181 patients

    Directory of Open Access Journals (Sweden)

    Hammerberg E Mark

    2011-10-01

    Full Text Available Abstract Background Surgical site wound closure plays a vital role in post-operative success. This effect is magnified in regard to commonly performed elective procedures such as total knee arthroplasty. The use of either sutures or staples for skin re-approximation remains a contested subject, which may have a significant impact on both patient safety and surgical outcome. The literature remains divided on this topic. Methods Two cohorts of patients at a level one trauma and regional referral center were reviewed. Cohorts consisted of consecutive total knee arthroplasties performed by two surgeons who achieved surgical wound re-approximation by either staples or absorbable subcuticular sutures. Outcome variables included time of surgery, wound dehiscence, surgical site infection per Center for Disease Control criteria and repeat procedures for debridement and re-closure. Results 181 patients qualified for study inclusion. Staples were employed in 82 cases (45.3% of total and sutures in 99 cases (54.7%. The staples group had no complications while the sutures group had 9 (9.1%. These consisted of: 4 infections (2 superficial, one deep, one organ/space; three patients required re-suturing for dehiscence; one allergic type reaction to suture material; and one gout flare resulting in dehiscence. The mean surgical time with sutures was 122.3 minutes (sd = 33.4 and with staples was 114 minutes (sd = 24.4. Conclusion This study demonstrated significantly fewer complications with staple use than with suture use. While all complications found in this study cannot be directly attributed to skin re-approximation method, the need for further prospective, randomized trials is established.

  12. Flat bones and sutures formation in the human cranial vault during prenatal development and infancy: A computational model.

    Science.gov (United States)

    Burgos-Flórez, F J; Gavilán-Alfonso, M E; Garzón-Alvarado, D A

    2016-03-21

    The processes of flat bones growth, sutures formation and interdigitation in the human calvaria are controlled by a complex interaction between genetic, biochemical and environmental factors that regulate bone formation and resorption during prenatal development and infancy. Despite previous experimental evidence accounting for the role of the main biochemical factors acting on these processes, the underlying mechanisms controlling them are still unknown. Therefore, we propose a mathematical model of the processes of flat bone and suture formation, taking into account several biological events. First, we model the growth of the flat bones and the formation of sutures and fontanels as a reaction diffusion system between two proteins: TGF-β2 and TGF-β3. The former is expressed by osteoblasts and allows adjacent mesenchymal cells differentiation on the bone fronts of each flat bone. The latter is expressed by mesenchymal cells at the sutures and inhibits their differentiation into osteoblasts at the bone fronts. Suture interdigitation is modelled using a system of reaction diffusion equations that develops spatio-temporal patterns of bone formation and resorption by means of two molecules (Wnt and Sclerostin) which control mesenchymal cells differentiation into osteoblasts at these sites. The results of the computer simulations predict flat bone growth from ossification centers, sutures and fontanels formation as well as bone formation and resorption events along the sutures, giving rise to interdigitated patterns. These stages were modelled and solved by the finite elements method. The simulation results agree with the morphological characteristics of calvarial bones and sutures throughout human prenatal development and infancy.

  13. Ab-interno scleral suture loop fixation with cow-hitch knot in posterior chamber intraocular lens decentration

    OpenAIRE

    Ertugrul Can; Nurullah Koçak; Özlem Eski Yücel; Adem Gül; Hilal Eser Öztürk; Osman Sayin

    2016-01-01

    Aim of Study: To describe a simplified ab-interno cow-hitch suture fixation technique for repositioning decentered posterior chamber intraocular lens (PC IOL). Materials and Methods: Two cases are presented with the surgical correction of decentered and subluxated IOL. Ab-interno scleral suture fixation technique with hitch-cow knot in the eye was performed with a ciliary sulcus guide instrument and 1 year follow-up was completed. Results: Both of the patients had well centered lenses postope...

  14. A comparative study of continuous versus interrupted suturing for repair of episiotomy or second degree perineal tear

    OpenAIRE

    Lopamudra Jena; Shyama Kanungo

    2015-01-01

    Background: This study has been taken up to assess the effects of continuous versus interrupted suturing methods on the incidence of short and long term postpartum maternal morbidity experienced by women following repair of episiotomy or second-degree perineal tears after vaginal birth. Methods: This comparative prospective study was conducted in department of obstetrics and gynaecology of S.C.B. medical college, Cuttack, Odisha to compare continuous suturing technique with interrupted m...

  15. One strategy for arthroscopic suture fixation of tibial intercondylar eminence fractures using the Meniscal Viper Repair System

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    Ochiai Satoshi

    2011-08-01

    Full Text Available Abstract Background Principles for the treatment of tibial intercondylar eminence fracture are early reduction and stable fixation. Numerous ways to treatment of this fracture have been invented. We designed a simple, low-invasive, and arthroscopic surgical strategy for tibial intercondylar eminence fracture utilizing the Meniscal Viper Repair System used for arthroscopic meniscal suture. Methods We studied 5 patients, who underwent arthroscopic suture fixation that we modified. The present technique utilized the Meniscal Viper Repair System for arthroscopic suture of the meniscus. With one handling, a high-strength ultra-high molecular weight polyethylene(UHMWPE suture can be passed through the anterior cruciate ligament (ACL and the loops for suture retrieval placed at both sides of ACL. Surgical results were evaluated by the presence or absence of bone union on plain radiographs, postoperative range of motion of the knee joint, the side-to-side differences measured by Telos SE, and Lysholm scores. Results The reduced position achieved after surgery was maintained and good function was obtained in all cases. The mean distance of tibia anterior displacement and assessment by Lysholm score showed good surgical results. Conclusion This method simplified the conventional arthroscopic suture fixation and increased its precision, and was applicable to Type II fractures that could be reduced, as well as surgically indicated Types III and IV. The present series suggested that our surgical approach was a useful surgical intervention for tibial intercondylar eminence fracture.

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

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    Marc Manganiello

    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 completion of UVA, post-operative anastomotic leak rate, and urinary incontinence were compared in patients undergoing UVA with 3-0 unidirectional-barbed suture vs. 3-0 MonocrylTM (Ethicon, 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 < 0.02. At 5 months, this difference was no longer evident. CONCLUSIONS: Time to complete the UVA was similar in the intervention and control groups. Rates of urine leak were also comparable

  17. LigaSure versus Conventional Suture Ligature for Vaginal Hysterectomy: a Randomized Controlled Trial

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    Mohamed Abd Elzaher, a, b, Ashraf Moawad, a, c and Hanaa Abu-Ria

    2011-07-01

    Full Text Available Introduction: Vaginal hysterectomy is considered to be the method of choice for removal of the uterus. Of particular concern for the vaginal surgeon is the ability to access, visualize, and legate structures while maintaining adequate hemostasis. Surgical hemostasis can be secured by a variety of methods, including mechanical means (sutures or vessel coagulation (diathermy. Electro-surgical vessel sealing (LigaSure is a new hemostatic system based on the combination of pressure and bipolar electrical energy and is able to seal vessels up to 7 mm in diameter. Objective: To assess the safety and efficacy of using the LigaSure vessel sealing system for securing the pedicles during vaginal hysterectomy in comparison with the conventional method of securing the pedicles by suture ligation. Design: Prospective randomized controlled trial. Setting: Obstetrics and Gynecology departments (Al-Kharj University Hospital- KSA, Enjab Hospital - UAE and Gulf Medical College and Research Centre- UAE. Methods: 80 patients undergoing vaginal hysterectomy for benign conditions were randomized to either LigaSure group (n=40 or Suture group (n=40. Main outcome measures: The primary outcome measures were the operative time and blood loss while the secondary outcome measures were the hospital stay and intra- and post-operative complications. Results: Patients in the LigaSure group had a significantly reduced operating time (37.1 ± 8.9 min vs. 63.8 ± 10.9 min; P < 0.001, operative blood loss (125.5 ± 33.2 mL vs. 264.6 ± 70.4 mL; P < 0.001, requirement of surgical sutures(1.2 ± 0.4 units vs. 8.2 ± 0.4 units; p < 0.001, pain status (2.0 ± 0.6 vs. 3.7 ± 0.7; P < 0.001, and hospital stay (30.3 ± 2.5 h vs. 45.7 ±10.5 h; P < 0.001 compared to the control group. The overall complication rate in the study was 10 % (8/80, and did not differ between patients of the LigaSure and control group. Conclusion: The use of LigaSure device can reduce operative time. It allows

  18. Sutures versus staples for wound closure in orthopaedic surgery: a randomized controlled trial

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    Shantz Jesse A

    2012-06-01

    Full Text Available Abstract Background A recently published meta-analysis comparing metallic staples to sutures in orthopaedic procedures revealed three fold increase in risk for infection in stapled wounds. The studies included in the meta-analysis are at risk of bias due to experimental design limitations. A large randomized controlled trial is proposed to direct orthopaedic surgeons in their choice of wound closure material. Methods/Design A parallel group randomized controlled trial with institutional review board approval will be conducted. Patients will be randomized intraoperatively to have skin wounds closed with sutures or staples. Dressings will be used to maintain blinding outcome assessors. The primary outcome measure will be a composite all-cause wound complication outcome measure composed of: infection, wound drainage, wound necrosis, blistering, dehiscence, suture abscess and material sensitivity reaction. An independent review board blinded to treatment assignment will adjudicate suspected complications based on clinical data. All deceased patients will also be reviewed. An interim analysis of complications will take place after half of the patients have been recruited. All data will be analyzed by a blinded statistician. Dichotomous primary and secondary outcome measures will be analyzed using the Chi-squared statistic. Continuous outcome measures will be analyzed using Student's t-test. Subgroup analysis will compare infection rates using sutures versus staples in each anatomic area (upper extremity, pelvis/acetabulum, hip/femur, knee, ankle. A further subgroup analysis will be conducted comparing trauma patients to elective surgery patients. Non-infected revision surgery will also be compared to primary surgery. Discussion Wound closure material is an afterthought for many orthopaedic surgeons. The combined results of several comparative trials suggests that the choice of wound closure materials may have an impact on the rate of surgical site

  19. A comparison of single-suture and double-suture incision closures in seaward-migrating juvenile Chinook salmon implanted with acoustic transmitters: implications for research in river basins containing hydropower structures

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Richard S.; Deters, Katherine A.; Cook, Katrina V.; Eppard, M. B.

    2013-07-15

    Reductions in the size of acoustic transmitters implanted in migrating juvenile salmonids have resulted in the ability to make shorter incisions that may warrant using only a single suture for closure. However, it is not known if one suture will sufficiently hold the incision closed, particularly when outward pressure is placed on the surgical site such as when migrating fish experience pressure changes associated with passage at hydroelectric dams. The objective of this research was to evaluate the effectiveness of single-suture incision closures on juvenile Chinook salmon (Oncorhynchus tshawytscha). Juvenile Chinook salmon were surgically implanted with a 2012 Juvenile Salmon Acoustic Telemetry System (JSATS) transmitter (0.30 g) and a passive integrated transponder tag (0.10 g) and incisions were closed with either one suture or two sutures. Mortality and tag retention were monitored and fish were examined after 7 and 14 days to evaluate tissue responses. In a separate experiment, surgically implanted fish were exposed to simulated turbine passage and then examined for expulsion of transmitters, expulsion of viscera through the incision, and mortal injury. With incisions closed using a single suture, there was no mortality or tag loss and similar or reduced tissue reaction compared to incisions closed with two sutures. Further, surgery time was significantly reduced when one suture was used, which leads to less handling and reduced stress. No tags were expelled during pressure scenarios and expulsion of viscera only occurred in two non-mortally injured fish (5%) with single sutures that were also exposed to very high pressure changes. No viscera expulsion was present in fish exposed to pressure scenarios likely representative of hydroturbine passage at many Columbia River dams (e.g. <2.7 ratio of pressure change; an acclimation pressure of 146.2 absolute kpa and a lowest exposure pressure of ~ 53.3 absolute kpa). Based on these results, we recommend the use of a

  20. Physicochemical and electrochemical characterization of battery separator prepared by radiation induced grafting of acrylic acid onto microporous polypropylene membranes

    Directory of Open Access Journals (Sweden)

    2009-05-01

    Full Text Available Mutual radiation grafting technique was used to graft acrylic acid on micrometer thick micro-porous polypropylene membrane using high-energy gamma radiation. Grafting could not be achieved in aqueous acrylic acid solution. The presence of Mohr’s salt effectively retarded the homopolymerization of acrylic acid but did not lead to grafting enhancement. Mohr’s salt in presence of acids was found to be effective in enhancing the grafting yield. Contact angle measurement studies of the grafted and radiation treated polypropylene showed that initial grafting as well as radiation treatment of poly(propylene in aqueous medium and in presence of Mohr’s salt enhances its affinity towards the grafting solution. The enhancement in the polar component of surface energy of treated polypropylene membrane is the primary cause of grafting enhancement. The membranes grafted to an extent of ~20% were found to perform comparably with the battery separator presently being used by battery industry.