Science.gov

Sample records for 10-0 nylon sutures

  1. COMPARATIVE STUDY OF MICROANASTOMOSIS WITH DISTINCT 10-0 NYLON SUTURES IN RATS

    PubMed Central

    Silva, Ricardo Teixeira e; Barros, Thiago Felipe Santos; de Carvalho, José Thomé; Ribeiro, André Araújo; Pires, André Fernandes; Wei, Teng Hsiang

    2016-01-01

    ABSTRACT Objective: The aim of this study is to compare micro-sutures commonly used in our midst. Methods: In this double-blind study, 30 Wistar rats were operated randomly divided into three groups matched according to the suture used (Nylon 10-0, 75micron, brands Microsuture(r), Polysuture(r) and Ethicon(r)). We analyzed the number of surgical nodes required, bleeding, surgical time and histological evaluation. Results: There was no significant difference between the amount of stitches of arterial suture per anastomosis. Surgical time was longer in Microsuture(r) group as compared to Polysuture(r) (p ≤ 0.05). Bleeding in Microsuture(r) group was higher when compared to the others (p <0.01). In the histological analysis, the Microsuture(r) group showed a greater tendency to develop fibrosis and aneurysm in surgical site than the others (p <0.01 and p≤0,05, respectively). Similarly, the Ethicon(r) group showed less tendency to myointimal proliferation than the rest. (p = 0.025). Conclusion: The results confirm the relevance of the choice of surgical thread as an independent determining factor for the success of the procedure, besides serving as a rational subsidy for a better cost-benefit analysis. Level of Evidence I, Experimental Study, Controlled Animal Study. PMID:26997912

  2. Antibacterial multifilament nylon sutures.

    PubMed

    Singhal, J P; Singh, J; Ray, A R; Singh, H

    1991-01-01

    Multifilament nylon fibers were made antibacterial by dopping with iodine. Nylon fibers were immersed in acetone solution of iodine for 48 hours at room temperature for dopping of iodine. It was observed that iodine uptake by the nylon fibers increased with the increase in concentration of iodine in the solution. Antibacterial activity of these iodine dopped samples was evaluated by measuring the zone of inhibition. The bacterial species used for this study were Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella pneumoniae. Iodine dopped fibers exhibited good antibacterial activity against these bacterial species. Release of iodine in distilled water is sustained for about 30 days. Antibacterial activity of the fibers decreases with the release of iodine in water. Ultra-violet and visible spectroscopic studies showed that tri-iodide ions were released from the dopped samples in the aqueous medium. These I3- ions might be responsible for the observed antibacterial activity. Fiber shrinks on iodine dopping leading to increase in the denier of the fiber. However effect of iodine dopping on the breaking load of fibers is not significant.

  3. A randomised controlled trial comparing skin closure in total knee arthroplasty in the same knee: nylon sutures versus skin staples

    PubMed Central

    Iamthanaporn, K.; Hongnaparak, T.; Tangtrakulwanich, B.

    2016-01-01

    Objectives Nylon sutures and skin staples are used commonly in total knee arthroplasty (TKA) surgical wound closure. However, there is no study that compares the wound healing efficacy and patient satisfaction scores of both techniques in the same knee. Methods We randomised 70 patients who underwent primary TKA into two groups. In one group of 34 patients, the skin at the upper half of the wound was closed with skin staples and the lower half of the wound was closed with simple interrupted nylon sutures. In the other group of 36 patients, the skin at the upper half of the wound was closed with nylon stitches and the lower half of the wound was closed with skin staples. We recorded the wound closure time, pain score at the time of stitch removal, wound complication rate, patient satisfaction score, and the Hollander wound evaluation score at the post-operative periods of five days, 14 days, six weeks, three months, and six months. Each half wound was analysed separately. Results The mean patient body mass index was 26.8 kg/m2 (standard deviation 6.3). A total of 70 nylon stitched wounds and 70 skin stapled wounds were analysed. There were no significant differences in wound complication rates, patient satisfaction score, and the Hollander wound evaluation score between both types of wounds (p > 0.05). The wound closure time for skin stapled wounds was significantly lower than the nylon stitched wounds (p < 0.001). However, the skin stapled wounds had a significantly higher pain score at the time of stitch removal (p < 0.001). Conclusion Skin staples and nylon stitches had comparable results with respect to wound healing and patient satisfaction in TKA wound closure in non-obese patients. The benefit of skin staples over nylon stitches was a decrease in operative time, but was more painful upon removal. Cite this article: V. Yuenyongviwat. A randomised controlled trial comparing skin closure in total knee arthroplasty in the same knee: nylon sutures versus skin

  4. The efficacy of a single continuous nylon suture for control of post keratoplasty astigmatism.

    PubMed Central

    Van Meter, W

    1996-01-01

    PURPOSE: Post operative adjustment of a single continuous suture is an effective means of reducing post keratoplasty astigmatism. This study evaluates post keratoplasty keratometry following suture adjustment with an adjusted suture in place and after the suture is removed. METHODS: Average keratometric astigmatism was measured over 24 months time in 26 patients with an adjusted continuous suture and 24 patients with a continuous suture that was not adjusted. Average keratometry in 43 patients with an adjusted continuous suture was compared with 37 patients with combined continuous and interrupted sutures. Finally, suture out astigmatism in 19 adjusted patients was compared to six patients with no adjustment. RESULTS: There was an increase in average corneal astigmatism over two years of 2.2 diopters in the adjusted group and 1.7 diopters in the non-adjusted group with sutures in place. One year following surgery, average keratometry flattened from 47.5 to 42.9 diopters in the adjusted continuous group and from 47.0 to 46.0 diopters in the group with combined continuous and interrupted sutures. Following suture removal, average astigmatism in patients who had suture adjustment was 4.4 diopters +/- 2.5 diopters (range 1-10 diopters), and 6.01 diopters (range 4-7) in the non-adjusted group. CONCLUSIONS: Average post keratoplasty astigmatism increases after a continuous suture is adjusted but the increase is comparable to patients with acceptable astigmatism who do not require adjustment. More progressive corneal flattening over 12 months time is seen with a continuous suture than which combined sutures. Average suture out astigmatism was 4.0 diopters following suture adjustment, compared to an average of 8.4 diopters prior to adjustment. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 7A FIGURE 7B PMID:8981721

  5. Interstitial therapy suing non-absorbable (Ir192 nylon ribbon) and absrobable (I125 "Vicryl") suturing techniques.

    PubMed

    Scott, W P

    1975-08-01

    Permanent and removable interstitial implantation techniques using absorbable and unabsorbable sutures are described. Most of these techniques can be performed in the clinic easily and quickly with basic instruments: needle holder, needle book, and hemoclips. Specifically, Ir192 (74-4 day half life, 300-610 keV, and 6.0 cm. hvl in tissue) nylon ribbon and I125 (60 day half life, 27-35 keV, and 2.0 cm. hvl in tissue) Vicryl sutures are described. A major advantage of the I125 over the Ir192 see (other than the fact that it can be permanently implanted and needs less radiation protection) is that the patient does not remain highly radioactive for as long a period due to hte extremely low I125 energy and may be allowed to leave the hospital. Both nuclides have the advantage of a long shelf life, making their use practical and economically feasible.

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

    Menovsky, Tomas; Beek, Johan F

    2003-01-01

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

  9. 21 CFR 878.5020 - Nonabsorbable polyamide surgical suture.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nonabsorbable polyamide surgical suture. 878.5020 Section 878.5020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES..., sterile, flexible thread prepared from long-chain aliphatic polymers Nylon 6 and Nylon 6,6 and...

  10. 21 CFR 878.5020 - Nonabsorbable polyamide surgical suture.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonabsorbable polyamide surgical suture. 878.5020 Section 878.5020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES..., sterile, flexible thread prepared from long-chain aliphatic polymers Nylon 6 and Nylon 6,6 and...

  11. 21 CFR 878.5020 - Nonabsorbable polyamide surgical suture.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nonabsorbable polyamide surgical suture. 878.5020 Section 878.5020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES..., sterile, flexible thread prepared from long-chain aliphatic polymers Nylon 6 and Nylon 6,6 and...

  12. 21 CFR 878.5020 - Nonabsorbable polyamide surgical suture.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nonabsorbable polyamide surgical suture. 878.5020 Section 878.5020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES..., sterile, flexible thread prepared from long-chain aliphatic polymers Nylon 6 and Nylon 6,6 and...

  13. Nylon and nylon blend nanotubes and nanorods

    NASA Astrophysics Data System (ADS)

    Simonetti, Valentina; Park, Jason Y.; Panaro, Nicholas J.; Kricka, Larry J.

    2008-02-01

    Nylon nanorods and nanotubes (200 nm diameter) were fabricated by the membrane wetting technique (solvent and melt wetting) from a range of nylons (6; 6,6; 6,9; 6,10; 6,12; 11; 12, 6(3)T) and nylon blended with different dyes (Nylon Cast Blue, Nylon 6/6 Black) or with molybdenum disulfide (Nylon cast MDS). The 65-μm long nylon nanotubes and nanorods were characterized by scanning electron microscopy. The nanoscale nylon 6,6 served as an effective high surface area alternative to a nylon membrane as a solid support in a chemiluminescent assay for nylon-bound biotinylated nucleic acids based on streptavidin- alkaline phosphatase and chemiluminescent detection of the bound alkaline phosphatase label with the dioxetane substrate, CDP-Star. Layer-by-layer deposition of the cationic polymer (Sapphire-II™; Tropix) onto the nylon 6,6 nanostructures prior to UV-cross-linking with biotinylated DNA resulted in further enhancement of binding and detection of biotinylated DNA.

  14. Comparison of vasovasostomy techniques in rats utilizing conventional microsurgical suture, carbon dioxide laser, and fibrin tissue adhesives.

    PubMed

    Ball, R A; Steinberg, J; Wilson, L A; Loughlin, K R

    1993-05-01

    An evaluation of vas reanastomoses in rats comparing suture only, carbon dioxide (CO2) laser-assisted, and fibrin-based tissue adhesive was performed in our laboratory. A cohort of 60 known fertile male Sprague Dawley rats initially underwent lower midline abdominal exploration and transection of their vas deferens bilaterally, followed by immediate microsurgical vasovasostomy by one of the three experimental methods. All groups initially had the severed vasa ends coapted by two or three transmural (mucosa through serosa) sutures of 10-0 nylon under an operating microscope. The conventionally sutured group had an additional four to six nylon 10-0 sutures placed externally in the serosa only to complete the anastomosis. The CO2 laser-assisted group underwent laser welding with denaturation of the serosa to seal the anastomosis. A fibrin-based tissue adhesive, produced by combining human cryoprecipitate and thrombin, was placed topically over the coapted vas ends to seal the anastomosis in the third group. Postoperative evaluation revealed similarities among the three surgical groups with the fibrin-based tissue adhesive group resulting in the highest patency rate (89%) and pregnancy rate (85%) as well as the lowest granulation rate (18%) and shortest operative time (27 minutes). The laser-assisted group resulted in the lowest pregnancy rate (68%), while the sewn anastomosis group had the lowest patency rate (76%). Both laser-assisted and conventionally sewn vasectomy reversals required significantly longer operative time (39 and 46 minutes, respectively) compared with the fibrin-based tissue adhesive-assisted procedures (p < 0.01). This study provides evidence that alternative microsurgical techniques may be utilized to perform uncomplicated, expeditious, and successful vasectomy reversals.

  15. Nylon separators. [thermal degradation

    NASA Technical Reports Server (NTRS)

    Lim, H. S.

    1977-01-01

    A nylon separator was placed in a flooded condition in K0H solution and heated at various high temperatures ranging from 60 C to 110 C. The weight decrease was measured and the molecular weight and decomposition product were analyzed to determine: (1) the effect of K0H concentration on the hydrolysis rate; (2) the effect of K0H concentration on nylon degradation; (3) the activation energy at different K0H concentrations; and (4) the effect of oxygen on nylon degradation. The nylon hydrolysis rate is shown to increase as K0H concentration is decreased 34%, giving a maximum rate at about 16%. Separator hydrolysis is confirmed by molecular weight decrease in age of the batteries, and the reaction of nylon with molecular oxygen is probably negligible, compared to hydrolysis. The extrapolated rate value from the high temperature experiment correlates well with experimental values at 35 degrees.

  16. A novel platelet-rich arterial thrombosis model in rabbits. Simple, reproducible, and dynamic real-time measurement by using double-opposing inverted-sutures model.

    PubMed

    Shieh, S J; Chiu, H Y; Shi, G Y; Wu, C M; Wang, J C; Chen, C H; Wu, H L

    2001-09-01

    Though numerous animal thrombosis models have been introduced, an easy, reliable, and reproducible arterial thrombosis model remains a continuing challenge prior to a thrombolytic study. In an effort to evaluate the efficiency of various recombinant thrombolytic agents with specific affinity to activated platelets in vivo, we developed a novel double-opposing inverted-sutures model to create a platelet-rich thrombus in the femoral artery of rabbits. The arteriotomy was done semicircumferentially, and variously sized microsurgical sutures were introduced intraluminally in a double-opposing inverted manner. The animals were divided into three groups according to the double-opposing inverted-sutures used: Group 1 with 10-0 nylon (n=6), Group 2 with 9-0 nylon (n=6), and Group 3 with 8-0 nylon (n=22). The superficial epigastric branch was cannulated with a thin polyethylene (PE) tube for intraarterial administration of the studied thrombolytic agent. The blood flow was continuously measured with a real-time ultrasonic flow meter. Within 2 h of installation of the sutures, there was no thrombus formation in either Group 1 or 2. In Group 3, the thrombosis rate was 91% (20 of 22) under a steady baseline flow (with an average of 12.23+/-2.40 ml/min). It was highly statistically significant with a P-value of .0000743 using Fisher's Exact Test. The averaged time to thrombosis was 21.8+/-9.8 min. The ultrasonic flow meter to record the dynamic real-time measurement of blood flow was a guideline for thrombus formation or dissolution, which was correlated with the morphological findings of stenotic status of the vessel detected by the Doppler sonography. The components of the thrombus were proven to be platelet-rich predominant by histological examination via hematoxylin and eosin (H&E) stain and transmission electron microscopy (TEM). To confirm that the double-opposing inverted-sutures model would be useful for a study of thrombolytic agents, we evaluated the effects of

  17. Retro iris suture fixation of a rigid intraocular lens.

    PubMed

    Haripriya, Aravind; Sharma, Sankalp S

    2016-11-01

    We present an iris suture fixation technique for a rigid poly(methyl methacrylate) (PMMA) intraocular lens (IOL). A 10-0 polypropylene suture on a long curved needle is used to preplace 2 iris suture bites 180 degrees apart. The suture loops below the iris are retracted through the main scleral tunnel using a Kuglen hook and a McPherson forceps. The 2 suture loops are twirled twice around the corresponding haptics of a standard 3-piece PMMA IOL, and the IOL is placed in the sulcus. After it is confirmed that the loop surrounds the haptic, the suture knot is tied to secure the IOL to the iris.

  18. Multidirectional Artificial Muscles from Nylon.

    PubMed

    Mirvakili, Seyed M; Hunter, Ian W

    2017-01-01

    Multidirectional artificial muscles are made from highly oriented nylon filaments. Thanks to the low thermal conductivity of nylon and its anisotropic thermal expansion, bending occurs when a nylon beam is differentially heated. This heat can be generated via a Joule heating mechanism or high power laser pulses.

  19. 6-0 nylon versus 6-0 vicryl rapide in chieloplasty

    PubMed Central

    Rao, J. K. Dayashankara; Luthra, Payal; Arya, Varun; Siwach, Vijay; Sheorain, Anil K.; Gupta, Megha

    2016-01-01

    Context: Facial cosmetic result is one of the most concerning issues for the parents who get their children operated for cleft lip. Moreover, the discomfort associated with the suture removal encourages one to use any new technology that may replace the need for suture placement. The type of suture material used in surgery has been a long-standing debate among surgeons. In this study, we compared rapidly absorbable suture material (Vicryl Rapide™) with nonabsorbable suture material (nylon). Aims: The aim of this study is to compare the appearance and course of scar, wound infection, and patient's parent perception using Vicryl Rapide and nylon in nonsyndromic congenital cleft lip repair. Settings and Design: This was a randomized prospective controlled clinical trial. Materials and Methods: Twenty patients, in the age group of 3–18 months treated for unilateral congenital cleft lip deformity, were included and randomly allocated to two groups with ten patients each. Skin suturing was done with 6-0 polyamide and 6-0 irradiated polyglactin in Groups A and B, respectively. Patients were evaluated at 1 week, 1, 3, 6 months, and 1 year postoperatively in person by the observer as well as by the patient's parent. Statistical Analysis Used: Descriptive statistical analysis was done using SPSS 20, and Student's t-test was applied. Results: It was found that Vicryl Rapide showed more hypopigmented scars and raised scars than nylon at the end of 1 year though overall appearance was comparable between the groups. Conclusions: Vicryl Rapide showed poorer cosmetic outcomes in terms of height and pigmentation of car as compared to nylon suture of same thickness. However, since scars tend to improve with time, a bigger sample size and a longer follow-up are required to generalize this statement. PMID:28299270

  20. GENIE Production Release 2.10.0

    SciTech Connect

    Alam, M.; Andreopoulos, C.; 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.

    2015-12-25

    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.

  1. 21 CFR 177.1500 - Nylon resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... determined by weighing a 1-gram to 5-gram sample first in air and then in freshly boiled distilled water at... manufactured by the condensation of equal-weight mixtures of nylon 66 salts and nylon 610 salts. (4) Nylon 6/66 resins manufactured by the condensation and polymerization of Nylon 66 salts and epsilon-caprolactam....

  2. 21 CFR 177.1500 - Nylon resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... determined by weighing a 1-gram to 5-gram sample first in air and then in freshly boiled distilled water at... manufactured by the condensation of equal-weight mixtures of nylon 66 salts and nylon 610 salts. (4) Nylon 6/66 resins manufactured by the condensation and polymerization of Nylon 66 salts and epsilon-caprolactam....

  3. 21 CFR 177.1500 - Nylon resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... determined by weighing a 1-gram to 5-gram sample first in air and then in freshly boiled distilled water at... manufactured by the condensation of equal-weight mixtures of nylon 66 salts and nylon 610 salts. (4) Nylon 6/66 resins manufactured by the condensation and polymerization of Nylon 66 salts and epsilon-caprolactam....

  4. 21 CFR 177.1500 - Nylon resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... determined by weighing a 1-gram to 5-gram sample first in air and then in freshly boiled distilled water at... manufactured by the condensation of equal-weight mixtures of nylon 66 salts and nylon 610 salts. (4) Nylon 6/66 resins manufactured by the condensation and polymerization of Nylon 66 salts and epsilon-caprolactam....

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

    PubMed Central

    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

  6. Ureteric Suture Urolithiasis Following Open Emergency Ureteric Repair

    PubMed Central

    Sarmah, Piyush B.; Kelly, Brian D.; Devarajan, Raghuram

    2016-01-01

    Suture urolithiasis is an unusual but recognised phenomenon following surgery on the urinary tract. We report a case in a 30-year-old man who sustained a gunshot injury to the left ureter in Burundi and underwent open ureteric repair in a regional hospital. He migrated to the UK and presented one year later with left loin pain. An intravenous urogram revealed two foci of calcification to the left of L3, within a peri-ureteric position. The patient underwent left-sided ureteroscopy where two calculi each formed around a nylon suture were discovered within a ureteric pseudo-diverticulum, and basketed. This is the first reported case of suture urolithiasis occurring following ureteric surgery. PMID:26989371

  7. Blends of zein and nylon-6

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blends of zein and nylon-6(55k)were used to produce solution cast films and electrospun fibers. Zein was blended with nylon-6 in formic acid solution. When the amount of nylon-6 was 8% or less a compatible blend formed. The blend was determined to be compatible based on physical property measurement...

  8. RETENTION OF SULFUR DIOXIDE BY NYLON FILTERS

    EPA Science Inventory

    Based on laboratory studies, recovery efficiencies of sulfur dioxide (SO2) were determined for nylon filters. The nylon filters used in these experiments were found to retain SO2. A relatively uniform amount (1.7%) was recoverable from each nylon filter, independent of relative...

  9. Enzymatic hydrolysis of nylons: quantification of the reaction rate of nylon hydrolase for thin-layered nylons.

    PubMed

    Nagai, Keisuke; Iida, Kazuki; Shimizu, Kimiaki; Kinugasa, Ryo; Izumi, Motoki; Kato, Dai-Ichiro; Takeo, Masahiro; Mochiji, Kozo; Negoro, Seiji

    2014-10-01

    Nylon hydrolase degrades various aliphatic nylons, including nylon-6 and nylon-66. We synthesized a nylon-66 copolymer (M w = 22,900, M n = 7,400), in which a part of an adipoyl unit (32 % molar ratio) of nylon-66 was replaced with a succinyl unit by interfacial polymerization. To quantify the reaction rate of the enzymatic hydrolysis of nylons at the surface of solid polymers, we prepared a thin layer of nylons on the bottom surface of each well in a polystyrene-based micro-assay plate. The thickness of the nylon layer was monitored by imaging analysis of the photographic data. More than 99 % of the copolymer with thicknesses of 260 nm (approximately 600 layers of polymer strands) were converted to water-soluble oligomers by nylon hydrolase (3 mg enzyme ml(-1)) at 30 °C within 60 h. These results were further confirmed by TLC analysis of the reaction products and by assay of liberated amino groups in the soluble fractions. The degradation rate of the thin-layered nylon-6 was similarly analyzed. We demonstrate that this assay enables a quantitative evaluation of the reaction rate of hydrolysis at the interface between the solid and aqueous phases and a quantitative comparison of the degradability for various polyamides.

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

    PubMed

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

    2014-01-01

    The purpose of this study was to determine which suture material is the most appropriate for dermal closure of terrestrial annelids. This paper describes the tissue reactions of the earthworm, Lumbricus terrestris, to five different types of suture materials in order to determine which suture material is the most appropriate for dermal closure. Silk, monofilament nylon, polydiaxonone, polyglactin 910, and chromic gut were studied. There was mild to moderate tissue reaction to all five suture materials. In all of the biopsies wound-healing reaction consisted of aggregates of blastemal cells which appeared in various stages of dedifferentiation from the body wall. Inflammatory cells infiltrated the wound sites, reminiscent of the typical foreign body reaction in vertebrates. The results indicate polyglactin 910 would be the best suture material with regards to tissue security and reaction scores. Chromic gut occupies the next position but there were problems with suture security over time. This appears to be the first suture material performance study on a terrestrial invertebrate. The earthworm, Lumbricus terrestris, was chosen for its wide availability, size, and the extensive species knowledge base. The earthworm may prove to be a good surgical/suture model for economically important invertebrates such as mollusks, tunicates, and insect larval stages.

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

    PubMed

    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.

  12. Craniofacial clefting and sutural dystopia.

    PubMed

    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.

  13. 21 CFR 177.1500 - Nylon resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...: Nylon resins Specific gravity Melting point(degrees Fahrenheit) Solubilityin boiling 4.2N HC1 Viscosity... by 100. (5) Viscosity number (VN). (i) The viscosity number (VN) for Nylon 6/12 resin in a 96 percent... ISO 307-1984(E), “Plastics-Polyamides-Determination of Viscosity Number,” which is incorporated...

  14. Evaluation of the effect of 4 types of knots on the mechanical properties of 4 types of suture material used in small animal practice.

    PubMed

    Avoine, Xytilis; Lussier, Bertrand; Brailovski, Vladimir; Inaekyan, Karine; Beauchamp, Guy

    2016-04-01

    The influence of the type of material used, knot configuration, and use of an additional throw on the tensile force at failure, the elongation, and the mode of failure of different configurations of linear sutures and knotted suture loops was evaluated in this in-vitro mechanical study. We hypothesized that all types of knots would significantly influence the initial force and elongation of suture materials and would influence the force and elongation at which the knotted loops break, but not their mode of failure. A total of 432 samples of 4 types of size 3-0 suture material (polydioxanone, polyglecaprone 25, polyglactin 910, and nylon), representing 9 configurations, were tested in a tensiometer. The configurations were 1 linear suture without a knot and the following loops: square (SQ) knot; surgeon's (SU) knot; granny (GR) knot; and sliding half-hitch (SHH) knot using either 4 and 5 or 3 and 4 throws, depending on the material. For polydioxanone, SQ and SU knots did not decrease the initial force at failure of the suture. Granny (GR) and SHH knots decreased the tensile force at failure and elongation by premature failure of the loop. For polyglecaprone 25, all knots decreased the initial force at failure of the suture, with SHH being weaker than the other knots. For coated polyglactin 910, all knots decreased the initial force at failure of the suture and slippage increased significantly compared with the other 3 sutures. The use of SQ knots with 3 throws did not result in a safe knot. For nylon, knots did not alter the original mechanics of the suture. In conclusion, all knots and types of suture material do not necessarily have the same effect on the initial tensile force at failure of suture materials.

  15. Quilting sutures for nasal septum.

    PubMed

    Hari, C; Marnane, C; Wormald, P J

    2008-05-01

    Suturing of the nasal septum after septal surgery is a commonly performed procedure designed to prevent complications such as septal haematoma and bleeding. It is also useful for closing any inadvertent tears of the septal mucosa and providing additional support for the cartilage pieces retained in septoplasty. In addition, the suture can be placed through the middle turbinates, stabilising them during the healing process. Placing knots for interrupted sutures in the posterior and middle part of the nasal septum can be technically difficult. We describe a continuous suturing technique for approximating the mucosal flaps following septal surgery.

  16. CXCL12/CXCR4 axis regulates neovascularization and lymphangiogenesis in sutured corneas in mice

    PubMed Central

    DU, LING-LING; LIU, PING

    2016-01-01

    The present study aimed to determine the plausible functional role of chemokine (C-X-C motif) ligand 12 (CXCL12)/chemokine (C-X-C motif) receptor 4 (CXCR4) in inflammatory corneal hemangiogenesis and lymphangiogenesis in vivo. Corneal hemangiogenesis and lymphangiogenesis were induced by placing an 11-0 nylon suture in an intrastromal position. The expression levels of the vascular endothelial growth factor (VEGF) family, CXCL12 and CXCR4 in the corneas were investigated in the corneas using reverse transcription-quantitative polymerase chain reaction and immunohistochemistry. Corneal hemangiogenic and lymphangiogenic responses were assessed by immunofluorescence using specific antibodies against cluster of differentiation 31 and lymphatic vessel endothelial hyaluronan receptor-1. Subconjunctival injection of AMD3100 to the sutured corneas was also performed. CXCL12/CXCR4 mRNA and protein expression levels increased markedly in suture-induced corneal neovascularization (CNV) and decreased with AMD3100 treatment. Hemangiogenesis and lymphangiogenesis were captured in images using immunofluorescence and were shown to be markedly increased with suture placement and reduced with AMD3100 treatment. VEGF-A/VEGFR-1 and VEGF-C/VEGFR-3 mRNA expression levels were upregulated in the suture placement and control groups, whereas the expression levels of all the factors were downregulated in the AMD3100 treatment group. The results from the present study demonstrated that CXCL12/CXCR4 interactions regulate hemangiogenesis and lymphangiogenesis in suture-induced CNV. AMD3100 may be a novel therapeutic target for the prevention of blindness. PMID:27121088

  17. [Surgical sutures. Principles and materials].

    PubMed

    Mousques, T; Levavasseur, F

    1989-06-01

    This article begins by a brief review of the advantages and modalities of the sutures. Then, the choice of the instrumentation (needle-holders, pliers and scissors) will be discussed. The suture material by itself (needles, threads) is studied. A description of the physical and biological properties of the different threads allows their comparison. The author's choice is the conclusion of this paper.

  18. Purification of caprolactam from recycled nylon

    DOEpatents

    Moens, L.

    1999-07-06

    A method is disclosed of removing 1,11-diamino-6-undecanone from the pyrolysis product of nylon comprising: (a) pyrolyzing nylon-6 to form a pyrolyzate containing a caprolactam mixture; (b) dissolving the caprolactam mixture in a solvent to form a solution; (c) passing carbon dioxide gas through the solution to form a precipitate; (d) removing the precipitate from the solution; and (e) recovering the purified caprolactam from the solution. 3 figs.

  19. Purification of caprolactam from recycled nylon

    DOEpatents

    Moens, Luc

    1999-01-01

    A method of removing 1,11-diamino-6-undecanone from the pyrolysis product of nylon comprising: a) pyrolyzing nylon-6 to form a pyrolyzate containing a caprolactam mixture; b) dissolving the caprolactam mixture in a solvent to form a solution; c) passing carbon dioxide gas through the solution to form a precipitate; d) removing the precipitate from the solution; and e) recovering the purified caprolactam from the solution.

  20. Molding Helmet Liners from Nylon Cloth Made from 1050 Denier Type 700 Nylon Yarns

    DTIC Science & Technology

    Helmet liners were satisfactorily molded from 14 ounce, 2 x 2 basket- weave nylon fabric made of 1050 denier, 168 filaments, 3 to 4 Z turns per inch...type 700 nylon yarn. These helmets liners satisfied the autoclave and the ballistics resistant requirements of Military Specification MIL-L-41800, Liner , Soldier’s Steel Helmet, 1 May 1961.

  1. Chemically modified nylons as supports for enzyme immobilization. Polyisonitrile-nylon

    PubMed Central

    Goldstein, Leon; Freeman, Amihay; Sokolovsky, Mordechai

    1974-01-01

    Four-component condensations between amine, carboxyl, isocyanide and aldehyde lead to the formation of N-substituted amides (Ugi, 1962). The present paper describes the use of such condensations for the introduction of chemically reactive groups on to the polyamide backbone of nylon. Polyisonitrile-nylon was synthesized by partial hydrolysis of nylon-6 powder, followed by resealing of the newly formed −CO2... NH2− pairs via a four-component condensation, by using acetaldehyde and 1,6-di-isocyanohexane. Polyisonitrile-nylon could also be converted into a diazotizable arylamino derivative, polyaminoaryl-nylon, by a four-component condensation by using a bifunctional amine, pp′-diaminodiphenylmethane, in the presence of an aldehyde and a carboxylate compound. The versatility of four-component condensations involving the isocyanide functional group of polyisonitrile-nylon allowed coupling of proteins, in an aqueous medium at neutral pH, through either their amino or carboxyl groups. Trypsin and papain were bound to polyisonitrile-nylon through their amino groups by a four-component condensation by using acetaldehyde and acetate; conversely, succinyl-(3-carboxypropionyl-)trypsin, pepsin and papain were coupled through their carboxyl groups in the presence of acetaldehyde and an amine (Tris). Diazotized polyaminoaryl-nylon could be utilized for the immobilization of papain, via the tyrosine residues of the enzyme. PMID:4618475

  2. Force Sensing in Surgical Sutures

    PubMed Central

    Horeman, Tim; Meijer, Evert-jan; Harlaar, Joris J.; Lange, Johan F.; van den Dobbelsteen, John J.; Dankelman, Jenny

    2013-01-01

    The tension in a suture is an important factor in the process of wound healing. If there is too much tension in the suture, the blood flow is restricted and necrosis can occur. If the tension is too low, the incision opens up and cannot heal properly. The purpose of this paper is to describe the design and evaluation of the Stitch Force (SF) sensor and the Hook-In Force (HIF) sensor. These sensors were developed to measure the force on a tensioned suture inside a closed incision and to measure the pulling force used to close the incision. The accuracy of both sensors is high enough to determine the relation between the force in the thread of a stitch and the pulling force applied on the suture by the physician. In a pilot study, a continuous suture of 7 stitches was applied on the fascia of the abdominal wall of multiple pigs to study this relationship. The results show that the max force in the thread of the second stitch drops from 3 (SD 1.2) to 1 (SD 0.3) newton after the 4th stitch was placed. During placement of the 5th, 6th and 7th stitch, the force in the 2nd stitch was not influenced anymore. This study indicates that in a continuous suture the force in the thread remains constant up to more than 3 stiches away from the pulled loose end of the suture. When a force feedback tool is developed specially for suturing in surgery on patients, the proposed sensors can be used to determine safety threshold for different types of tissue and sutures. PMID:24376812

  3. 31 CFR 10.0 - Scope of part.

    Code of Federal Regulations, 2010 CFR

    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...

  4. The influence of suturing and sepsis on the development of postoperative peritoneal adhesions.

    PubMed Central

    O'Leary, D. P.; Coakley, J. B.

    1992-01-01

    Postoperative peritoneal adhesions are a major cause of morbidity. The purpose of this study was to investigate the potential contributions of suturing and sepsis to their formation in animals undergoing laparotomy. Suturing the peritoneum with plain catgut was associated with a high incidence of adhesions to the wound at 8 days (11/15), but this was significantly less at 25 days (5/15, P less than 0.04). Use of monofilament nylon, or non-suture, were each associated with a low incidence of adhesions. Wound strength was significantly greater at 25 days than at 8 days (P less than 0.0005), but did not differ between groups. In a separate experiment, bacterial infection, even in the absence of a particulate carrier, proved to be a potent cause of postoperative peritoneal adhesions (8/9, P = 0.02) compared with uninfected controls (3/10). Suturing the peritoneum in the presence of infection caused an especially high incidence of adhesions to the wound (8/9, P = 0.004 vs 2/10 unsutured). It is concluded that the lowest incidence of adhesions to the wound is likely to be obtained, both in uninfected and in infected cases, if the peritoneum is not sutured during closure of abdominal wounds, and that such an approach does not compromise wound strength. PMID:1567133

  5. Bending artificial muscle from nylon filaments

    NASA Astrophysics Data System (ADS)

    Mirvakili, Seyed M.; Hunter, Ian W.

    2016-04-01

    Highly oriented nylon and polyethylene fibers shrink in length and expand in diameter when heated. Using this property, in this work, for the first time we are introducing a type of bending artificial muscle from nylon filaments such as fishing line. Reversible radius of curvature of 0.23 mm-1 was achieved with maximum reversible bending amplitude of 115 mm for the nylon bending actuator. Peak force of up to 2040 mN was measured with a catch-state force of up to 40% of the active force. A 3 dB roll-off frequency of around 0.7 Hz was observed in the frequency response of the bending actuator in water.

  6. Maintenance Manual for Carpets Made with Du Pont Carpet Nylon.

    ERIC Educational Resources Information Center

    Du Pont Corp., Wilmington, DE.

    Information is divided into the following sections--(1) the selection of nylon carpet, (2) the advantages of nylon for carpets, (3) the characteristics of nylon carpet, (4) soiling and soil retardants, (5) vacuum cleaning, (6) spot cleaning and freshening of traffic lanes, (7) wet cleaning (shampooing), and (8) miscellaneous carpet maintenance…

  7. A Pentagram Suture Technique for Closing Tumor Resection Sites in the Face

    PubMed Central

    Takeuchi, Masaki; Mori, Satoko; Sakurai, Hiroyuki

    2015-01-01

    Background: Resection of facial skin tumors aims to remove the tumors completely and make the surgical scar unnoticeable as much as possible. By improving the purse string suture method, we developed a new pentagram suture technique that enables simple and safe suturing of small to large defects with early satisfactory esthetic outcomes. The surgical outcomes of a case series were examined in this report. Methods: As in drawing a unicursal star, 5 suture sites were marked at specific intervals around the defect area. A needle with 5-0 polydioxanone suture was passed from the subcutaneous tissue to the superficial dermal layer at one site and then from the superficial dermal layer to the subcutaneous layer at the next site, and the process was repeated until the pentagram was complete. When apposition was not tight enough, a couple of external stitches were added using 6-0 nylon suture. Results: In 13 patients (16 benign or malignant tumors; mean age, 51.1 years) with a mean tumor size of 10.1 ± 5.2 mm and postoperative skin defect diameter of 12.1 ± 8.2 mm, closure did not result in high tension on the suture, and there was reduced mechanical stress at the wound margin. Surgical outcomes were good esthetically at 6 months after surgery without keloid formation or scar contracture. None of the patients had postoperative pain, infection, or tumor recurrence. Conclusions: This simple alternative method for the closure of facial skin defects after skin tumor excision could be performed easily and provided satisfactory surgical outcomes. PMID:26495212

  8. Nylon wool purification alters the activation of T cells.

    PubMed

    Wohler, Jillian E; Barnum, Scott R

    2009-02-01

    Purification of lymphocytes, particularly T cells, is commonly performed using nylon wool. This enrichment method selectively retains B cells and some myeloid cells allowing a significantly more pure T cell population to flow through a nylon wool column. T cells purified in this fashion are assumed to be unaltered and functionally naïve, however some studies have suggested aberrant in vitro T cell responses after nylon wool treatment. We found that nylon wool purification significantly altered T cell proliferation, expression of activation markers and production of cytokines. Our results suggest that nylon wool treatment modifies T cell activation responses and that caution should be used when choosing this purification method.

  9. Nylon screws make inexpensive coil forms

    NASA Technical Reports Server (NTRS)

    Aucoin, G.; Rosenthal, C.

    1978-01-01

    Standard nylon screws act as coil form copper wire laid down in spiral thread. Completed coil may be bonded to printed-circuit board. However, it is impossible to tune coil by adjusting spacing between windings, technique sometimes used with air-core coils.

  10. Terminal Area Simulation System User's Guide - Version 10.0

    NASA Technical Reports Server (NTRS)

    Switzer, George F.; Proctor, Fred H.

    2014-01-01

    The Terminal Area Simulation System (TASS) is a three-dimensional, time-dependent, large eddy simulation model that has been developed for studies of wake vortex and weather hazards to aviation, along with other atmospheric turbulence, and cloud-scale weather phenomenology. This document describes the source code for TASS version 10.0 and provides users with needed documentation to run the model. The source code is programed in Fortran language and is formulated to take advantage of vector and efficient multi-processor scaling for execution on massively-parallel supercomputer clusters. The code contains different initialization modules allowing the study of aircraft wake vortex interaction with the atmosphere and ground, atmospheric turbulence, atmospheric boundary layers, precipitating convective clouds, hail storms, gust fronts, microburst windshear, supercell and mesoscale convective systems, tornadic storms, and ring vortices. The model is able to operate in either two- or three-dimensions with equations numerically formulated on a Cartesian grid. The primary output from the TASS is time-dependent domain fields generated by the prognostic equations and diagnosed variables. This document will enable a user to understand the general logic of TASS, and will show how to configure and initialize the model domain. Also described are the formats of the input and output files, as well as the parameters that control the input and output.

  11. Particle Collection Efficiency for Nylon Mesh Screens

    PubMed Central

    Cena, Lorenzo G.; Ku, Bon-Ki; Peters, Thomas M.

    2015-01-01

    Mesh screens composed of nylon fibers leave minimal residual ash and produce no significant spectral interference when ashed for spectrometric examination. These characteristics make nylon mesh screens attractive as a collection substrate for nanoparticles. A theoretical single-fiber efficiency expression developed for wire-mesh screens was evaluated for estimating the collection efficiency of submicrometer particles for nylon mesh screens. Pressure drop across the screens, the effect of particle morphology (spherical and highly fractal) on collection efficiency and single-fiber efficiency were evaluated experimentally for three pore sizes (60, 100 and 180 μm) at three flow rates (2.5, 4 and 6 Lpm). The pressure drop across the screens was found to increase linearly with superficial velocity. The collection efficiency of the screens was found to vary by less than 4% regardless of particle morphology. Single-fiber efficiency calculated from experimental data was in good agreement with that estimated from theory for particles between 40 and 150 nm but deviated from theory for particles outside this size range. New coefficients for the single-fiber efficiency model were identified that minimized the sum of square error (SSE) between the values estimated with the model and those determined experimentally. Compared to the original theory, the SSE calculated using the modified theory was at least one order of magnitude lower for all screens and flow rates with the exception of the 60-μm pore screens at 2.5 Lpm, where the decrease was threefold. PMID:26692631

  12. Application of Intrared Absorbers to Nylon 6,6

    DTIC Science & Technology

    1974-07-01

    is trans- fered from the dyes to the IR 99, thus increasing the rate of photodegradation of IR 99. It should be noted that higher amounts of these...Physical) Infrared Infrared Radiation Textiles Nylon Dyes Nylon 6,6 Organic Salts Organic Compounds Salts Fluorescence 20. ABSTRACT... dyeing the nylon with an acid dye , or pre-treating it with certain organ- ic salts increased the uptake of infrared absorber, but light stability was

  13. Absorption of water and lubricating oils into porous nylon

    NASA Technical Reports Server (NTRS)

    Bertrand, P. A.

    1995-01-01

    Oil and water absorption from air into sintered porous nylon can be described by infiltration into the pores of the material. This process can be modeled by a diffusion-like mechanism. For water absorption, we find a formal diffusion coefficient of 1.5 x 10(exp -4)sq cm/min when the nylon is initially dry. The diffusion coefficient is 4 x 10(exp -6)sq cm/min when the nylon is oil-impregnated prior to air exposure. In a 52% RH atmosphere, dry nylon absorbs 3% w/w water, and oil-impregnated nylon absorbs 0.6% w/w water. For oil absorption there are three steps: (1) surface absorption and infiltration into (2) larger and (3) smaller pores. Surface absorption is too fast to be measured in these experiments. The diffusion coefficient for the second step is 6 x 10(exp -4)sq cm/min for SRG-60 oil into dry nylon and 4 x 10(exp -4)sq cm/min for air-equilibrated nylon. The diffusion coefficient for the third step is about 1 x 10(exp -6)sq cm/min for both cases. The total amount of oil absorbed is 31% w/w. The interaction between water and nylon is not as strong as that between water and cotton-phenolic: oil can replace water, and only a small amount of water can enter previously oil-impregnated nylon.

  14. Comparing Skin Staples to Sutures

    PubMed Central

    Shuster, Michael

    1989-01-01

    In a prospective randomized study, 52 lacerations requiring closure in the emergency department were either stapled or sutured. Six participating emergency physicians closed the wounds and recorded data about the laceration and the treatment provided. Patients visited their own family physicians for removal of the closures. Forty family physicians removed closures from 44 lacerations and reported follow-up data on discomfort levels, ease of closure removal, and cosmetic results. Lacerations were closed 2.7 times faster by the staple method (p<0.001), and there were no clinically significant differences between the two methods with respect to discomfort, infection rates, cosmetic result, or ease of removal. The staple device we used was more expensive than sutures. We concluded that the staple method of closure is safe, comfortable, and effective in the emergency department setting, and that the method's speed offsets its greater expense in some circumstances. PMID:21248986

  15. Nylon-3 polymers with selective antifungal activity.

    PubMed

    Liu, Runhui; Chen, Xinyu; Hayouka, Zvi; Chakraborty, Saswata; Falk, Shaun P; Weisblum, Bernard; Masters, Kristyn S; Gellman, Samuel H

    2013-04-10

    Host-defense peptides inhibit bacterial growth but show little toxicity toward mammalian cells. A variety of synthetic polymers have been reported to mimic this antibacterial selectivity; however, achieving comparable selectivity for fungi is more difficult because these pathogens are eukaryotes. Here we report nylon-3 polymers based on a novel subunit that display potent antifungal activity (MIC = 3.1 μg/mL for Candida albicans ) and favorable selectivity (IC10 > 400 μg/mL for 3T3 fibroblast toxicity; HC10 > 400 μg/mL for hemolysis).

  16. Classroom Illustrations of Acidic Air Pollution Using Nylon Fabric

    ERIC Educational Resources Information Center

    Campbell, Dean J.; Wright, Emily A.; Dayisi, Mardhia O.; Hoehn, Michael R.; Kennedy, Branden F.; Maxfield, Brian M.

    2011-01-01

    In 1970, deposition of fly ash from a coal burning power plant in downtown Peoria produced minor damage in the vicinity of its smokestack, including runs in ladies nylon stockings. In this article, we review the historical event and discuss the chemistry behind the depolymerization of the nylon, as well as laboratory experiments demonstrating how…

  17. Rigid amorphous fraction of Nylon 11 determined from TMDSC

    NASA Astrophysics Data System (ADS)

    Mao, Bin; Cebe, Peggy

    2012-02-01

    High precision, high accuracy heat capacity measurements were used to study both neat Nylon 11 and Nylon 11 nanocomposites which had been prepared by different processing procedures. The heat capacity step at the glass transition temperature was characterized from the reversing flow using temperature modulated differential scanning calorimetry, and this allows us to determine the mobile amorphous fraction. Heat fusion was obtained from endotherm area of the total heat flow curve, and was correlated with the degree of crystallinity determined from X-ray diffraction. Based on three phase model of the semicrystalline polymer structure, the rigid amorphous fraction (RAF) in Nylon 11 could be calculated. Studied Nylon 11 samples include solution cast, liquid quenched, and isothermally crystallized films, solution cast films containing multi-walled carbon nanotubes, and electrospun fibers. We observed that a rigid amorphous fraction exists in all Nylon 11 samples, and the amount of RAF is strongly dependent upon the crystalline fraction and the nanofiller content.

  18. Nylon Wool Purification Alters the Activation of T Cells

    PubMed Central

    Wohler, Jillian E.; Barnum, Scott R.

    2009-01-01

    Purification of lymphocytes, particularly T cells, is commonly performed using nylon wool. This enrichment method selectively retains B cells and some myeloid cells allowing a significantly more pure T cell population to flow through a nylon wool column. T cells purified in this fashion are assumed to be unaltered and functionally naïve, however some studies have suggested aberrant in vitro T cell responses after nylon wool treatment. We found that nylon wool purification significantly altered T cell proliferation, expression of activation markers and production of cytokines. Our results suggest that nylon wool treatment modifies T cell activation responses and that caution should be used when choosing this purification method. PMID:18952296

  19. Experimental investigation on the mechanical properties of glass fiber reinforced nylon

    NASA Astrophysics Data System (ADS)

    Nuruzzaman, D. M.; Iqbal, A. K. M. Asif; Oumer, A. N.; Ismail, N. M.; Basri, S.

    2016-02-01

    In this study, the influence of different weight percentages of glass fiber (GF) reinforcement on the mechanical properties of nylon (PA6) composite is investigated. Test specimens of pure nylon, 95% nylon + 5% GF, 90% nylon + 10% GF, 85% nylon + 15% GF and 80% nylon + 20% GF are prepared using an injection molding machine. In the experiments, tensile tests and impact tests are carried out. The obtained results reveal that mechanical properties of the nylon composites are significantly influenced by the weight percentage of glass fiber. From the tensile test results, it is observed that pure nylon has the lowest elastic modulus and yield strength whereas 80% nylon + 20% GF composite shows the highest elastic modulus and yield strength. Moreover, pure nylon shows the lowest tensile strength while 80% nylon + 20% GF shows significantly improved tensile strength. Results show that elongation at break is remarkably high for pure nylon whereas it is very low for 80% nylon + 20% GF. Izod impact test results reveal that, 85% nylon + 15% GF composite has the highest impact strength or toughness whereas 95% nylon + 5% GF composite shows the lowest impact strength. Furthermore, 80% nylon + 20% GF composite shows somewhat less impact strength or toughness than 85% nylon + 15% GF composite.

  20. Mesh Sutured Repairs of Abdominal Wall Defects

    PubMed Central

    Lanier, Steven T.; Jordan, Sumanas W.; Miller, Kyle R.; Ali, Nada A.; Stock, Stuart R.

    2016-01-01

    Background: A new closure technique is introduced, which uses strips of macroporous polypropylene mesh as a suture for closure of abdominal wall defects due to failures of standard sutures and difficulties with planar meshes. Methods: Strips of macroporous polypropylene mesh of 2 cm width were passed through the abdominal wall and tied as simple interrupted sutures. The surgical technique and surgical outcomes are presented. Results: One hundred and seven patients underwent a mesh sutured abdominal wall closure. Seventy-six patients had preoperative hernias, and the mean hernia width by CT scan for those with scans was 9.1 cm. Forty-nine surgical fields were clean-contaminated, contaminated, or dirty. Five patients had infections within the first 30 days. Only one knot was removed as an office procedure. Mean follow-up at 234 days revealed 4 recurrent hernias. Conclusions: Mesh sutured repairs reliably appose tissue under tension using concepts of force distribution and resistance to suture pull-through. The technique reduces the amount of foreign material required in comparison to sheet meshes, and avoids the shortcomings of monofilament sutures. Mesh sutured closures seem to be tolerant of bacterial contamination with low hernia recurrence rates and have replaced our routine use of mesh sheets and bioprosthetic grafts. PMID:27757361

  1. [Migration of monomers and primary aromatic amines from nylon products].

    PubMed

    Mutsuga, Motoh; Yamaguchi, Miku; Ohno, Hiroyuki; Kawamura, Yoko

    2010-01-01

    Migration of 2 kinds of monomer and 21 kinds of primary aromatic amines (PAAs) from 21 kinds of nylon products such as turners, ladles and wrap film were determined. Samples were classified as regards materials by mean of pyrolysis-GC/MS. One sample was classified as nylon 6, 15 samples as nylon 66 and three samples as nylon 6/66 copolymers, while two samples were laminate of nylon 6 with polyethylene or polypropylene. All of the nylon 66 samples contained a small amount of ε-caprolactam (CPL), which is the nylon 6 monomer. Migration levels of monomers and PAAs at 60°C for 30 min into 20% ethanol were measured by LC/MS/MS. CPL was detected at the level of 0.015-38 µg/mL from all samples, excluding one wrap film sample, and 1,6-hexamethylenediamine was detected at the level of 0.002-0.013 µg/mL from all nylon 66 samples and one nylon 6/66 sample. In addition, 0.006-4.3 µg/mL of 4,4'-diaminodiphenylmethane from three samples, 0.032-0.23 µg/mL of aniline from four samples, 0.001 µg/mL of 4-chloroaniline from two samples, and 0.002 µg/mL of 2-toluidine and 0.066 mg/mL of 1-naphthylamine from one sample each were detected. The migration levels at 95 or 121°C were about 3 and 10 times the 60°C levels, respectively.

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

    PubMed

    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.

  3. Total knee arthroplasty closure with barbed sutures.

    PubMed

    Eickmann, Tom; Quane, Erika

    2010-09-01

    Bidirectional barbed sutures, which do not require the tying of knots, have the potential to reduce closure times of total knee arthroplasty (TKA) wounds without adverse effect to wound security, cosmesis, or infection risk. In this retrospective study, data were reviewed from TKAs performed between January 2007 and September 2008. For 88 of these procedures, conventional absorbable sutures were used for interrupted closure of the retinacular and subcutaneous layers and for running closure of the subcuticular layer. For 90 procedures, bidirectional barbed absorbable sutures were used for running closure of the retinacular and subcutaneous layers. Surgeries performed with barbed sutures were significantly faster than those performed with conventional sutures (mean times of 74.3 minutes and 85.8 minutes, respectively, p < 0.001) with no detrimental clinical effects.

  4. Nylon-muscle-actuated robotic finger

    NASA Astrophysics Data System (ADS)

    Wu, Lianjun; Jung de Andrade, Monica; Rome, Richard S.; Haines, Carter; Lima, Marcio D.; Baughman, Ray H.; Tadesse, Yonas

    2015-04-01

    This paper describes the design and experimental analysis of novel artificial muscles, made of twisted and coiled nylon fibers, for powering a biomimetic robotic hand. The design is based on circulating hot and cold water to actuate the artificial muscles and obtain fast finger movements. The actuation system consists of a spring and a coiled muscle within a compliant silicone tube. The silicone tube provides a watertight, expansible compartment within which the coiled muscle contracts when heated and expands when cooled. The fabrication and characterization of the actuating system are discussed in detail. The performance of the coiled muscle fiber in embedded conditions and the related characteristics of the actuated robotic finger are described.

  5. Ancient suture zones within continents.

    PubMed

    Moores, E M

    1981-07-03

    Ancient suture belts within continents are deformed regions which contain the remnants of former ocean basins. They form when two continents or island arcs that earlier were separated by an ocean basin converge and collide during plate tectonic activity. These belts provide the only record we have of deep oceanic crust and of ancient sea-floor processes for the first 94 percent of the earth's history, that is, prior to the oldest preserved crust in the oceans. Ten criteria for the recognition and interpretation of these ancient belts are discussed. A comprehensive program for the study of these belts should have great scientific and economic benefit for the United States and would be relatively cheap compared to other large national scientific efforts.

  6. The double loop mattress suture

    PubMed Central

    Biddlestone, John; Samuel, Madan; Creagh, Terry; Ahmad, Tariq

    2014-01-01

    An interrupted stitch type with favorable tissue characteristics will reduce local wound complications. We describe a novel high-strength, low-tension repair for the interrupted closure of skin, cartilage, and muscle, the double loop mattress stitch, and compare it experimentally with other interrupted closure methods. The performance of the double loop mattress technique in porcine cartilage and skeletal muscle is compared with the simple, mattress, and loop mattress interrupted sutures in both a novel porcine loading chamber and mechanical model. Wound apposition is assessed by electron microscopy. The performance of the double loop mattress in vivo was confirmed using a series of 805 pediatric laparotomies/laparoscopies. The double loop mattress suture is 3.5 times stronger than the loop mattress in muscle and 1.6 times stronger in cartilage (p ≤ 0.001). Additionally, the double loop mattress reduces tissue tension by 66% compared with just 53% for the loop mattress (p ≤ 0.001). Wound gapping is equal, and wound eversion appears significantly improved (p ≤ 0.001) compared with the loop mattress in vitro. In vivo, the double loop mattress performs as well as the loop mattress and significantly better than the mattress stitch in assessments of wound eversion and dehiscence. There were no episodes of stitch extrusion in our series of patients. The mechanical advantage of its intrinsic pulley arrangement gives the double loop mattress its favorable properties. Wound dehiscence is reduced because this stitch type is stronger and exerts less tension on the tissue than the mattress stitch. We advocate the use of this novel stitch wherever a high-strength, low-tension repair is required. These properties will enhance wound repair, and its application will be useful to surgeons of all disciplines. PMID:24698436

  7. 21 CFR 177.2355 - Mineral reinforced nylon resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ....1500, reinforced with up to 40 weight percent of calcium silicate and up to 0.5 weight percent 3... calcium silicate. (b) The mineral reinforced nylon resins may contain up to 0.2 percent by weight...

  8. Moisture dependence of positron annihilation spectra in nylon-6

    NASA Technical Reports Server (NTRS)

    Singh, J. J.; St. Clair, T. L.; Holt, W. H.; Mock, W., Jr.

    1984-01-01

    Positron annihilation time spectra have been measured in nylon-6 samples as a function of their moisture content. The measured average long life component lifetime values are: 1722 + or - 47 ps (dry), 1676 + or - 40 ps (14.6 percent saturation value), 1719 + or - 26 ps (29.3 percent saturation value), 1720 + or - 35 ps (50 percent of saturation value), 1857 + or - 35 ps (78.1 percent saturation value), and 1936 + or - 57 ps (saturated). It appears that nylon-6 has a special affinity for water at low concentration levels where H2O molecules enter between the (C = O - H-N) chemical bonds between nylon molecular chains. As the water concentration increases beyond a critical level, nylon-6 specimens start trapping H2O molecules in other bond sites or potential wells. The trapped water increases the free volume in the test specimens and reduces Ps atom formation as well as its subsequent decay rate.

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

    PubMed Central

    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 (P<0.05). Radiographic analysis showed that the hidden X suture had a significant effect in preserving horizontal width and minimizing vertical reduction in comparison to X suture (P<0.05). Conclusions Our study provided clinical 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

  10. Suture slippage in knotless suture anchors resulting in subacromial-subdeltoid bursitis.

    PubMed

    Hayeri, Mohammad Reza; Keefe, Daniel T; Chang, Eric Y

    2016-05-01

    Rotator cuff repair using a suture bridge and knotless suture anchors is a relatively new, but increasingly used technique. The suture bridge technique creates an anatomically similar and more secure rotator cuff repair compared with conventional arthroscopic techniques and the use of knotless anchors eliminates the challenges associated with knot tying during arthroscopic surgery. However, previous in vitro biomechanical tests have shown that the hold of the suture in a knotless suture anchor is far lower than the pullout strength of the anchor from bone. Up until now slippage has been a theoretical concern. We present a prospectively diagnosed case of in vivo suture loosening after rotator cuff repair using a knotless bridge technique resulting in subacromial-subdeltoid bursitis.

  11. Three-dimensional Structure of Nylon Hydrolase and Mechanism of Nylon-6 Hydrolysis*

    PubMed Central

    Negoro, Seiji; Shibata, Naoki; Tanaka, Yusuke; Yasuhira, Kengo; Shibata, Hiroshi; Hashimoto, Haruka; Lee, Young-Ho; Oshima, Shohei; Santa, Ryuji; Oshima, Shohei; Mochiji, Kozo; Goto, Yuji; Ikegami, Takahisa; Nagai, Keisuke; Kato, Dai-ichiro; Takeo, Masahiro; Higuchi, Yoshiki

    2012-01-01

    We performed x-ray crystallographic analyses of the 6-aminohexanoate oligomer hydrolase (NylC) from Agromyces sp. at 2.0 Å-resolution. This enzyme is a member of the N-terminal nucleophile hydrolase superfamily that is responsible for the degradation of the nylon-6 industry byproduct. We observed four identical heterodimers (27 kDa + 9 kDa), which resulted from the autoprocessing of the precursor protein (36 kDa) and which constitute the doughnut-shaped quaternary structure. The catalytic residue of NylC was identified as the N-terminal Thr-267 of the 9-kDa subunit. Furthermore, each heterodimer is folded into a single domain, generating a stacked αββα core structure. Amino acid mutations at subunit interfaces of the tetramer were observed to drastically alter the thermostability of the protein. In particular, four mutations (D122G/H130Y/D36A/E263Q) of wild-type NylC from Arthrobacter sp. (plasmid pOAD2-encoding enzyme), with a heat denaturation temperature of Tm = 52 °C, enhanced the protein thermostability by 36 °C (Tm = 88 °C), whereas a single mutation (G111S or L137A) decreased the stability by ∼10 °C. We examined the enzymatic hydrolysis of nylon-6 by the thermostable NylC mutant. Argon cluster secondary ion mass spectrometry analyses of the reaction products revealed that the major peak of nylon-6 (m/z 10,000–25,000) shifted to a smaller range, producing a new peak corresponding to m/z 1500–3000 after the enzyme treatment at 60 °C. In addition, smaller fragments in the soluble fraction were successively hydrolyzed to dimers and monomers. Based on these data, we propose that NylC should be designated as nylon hydrolase (or nylonase). Three potential uses of NylC for industrial and environmental applications are also discussed. PMID:22187439

  12. [Assessing the effect of subcuticular buried sutures with subcutaneous closed suction drain to prevent surgical site infection in patients undergoing total cystectomy with urinary diversion using intestine].

    PubMed

    Kanamaru, Sojun; Tsuchihashi, Kazunari; Makino, Yuki; Shimizu, Yosuke; Ito, Noriyuki

    2014-11-01

    We assessed the effect of subcuticular buried sutures with subcutaneous closed suction drain to prevent surgical site infection (SSI) in patients undergoing total cystectomy with urinary diversion using the intestine. We reviewed the clinical charts of 43 consecutive patients who underwent total cystectomy with urinary diversion using the intestine from February 2006 to March 2011 at Nishi-Kobe Medical Center. All patients received intravenous prophylactic antibiotics before and throughout surgery as well as for three days after surgery. Skin closure was performed with interrupted vertical mattress sutures with 2-0 nylon on the first 22 patients (mattress group), and with interrupted subcuticular buried sutures with 4-0 absorbable monofilament with subcutaneous closed suction drain on the remaining 21 patients (subcuticular buried suture with subcutaneous drain; SBD group). SSI occurred in 7 (31.8%) patients in the mattress group, but did not affect any patient in the SBD group. We compared risk factors for SSI between the groups, and found that the method of skin closure was significant risk factor for SSI (P = 0.005). We concluded that interrupted subcuticular buried sutures with 4-0 absorbable monofilament with subcutaneous suction drain is effective for prevention of SSI in total cystectomy with urinary diversion using the intestine.

  13. Strength of different meniscus suturing techniques.

    PubMed

    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.

  14. 21 CFR 878.4495 - Stainless steel suture.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 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...

  15. 21 CFR 878.4495 - Stainless steel suture.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 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...

  16. 21 CFR 878.4495 - Stainless steel suture.

    Code of Federal Regulations, 2010 CFR

    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...

  17. 21 CFR 878.4495 - Stainless steel suture.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 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...

  18. 21 CFR 878.4495 - Stainless steel suture.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 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...

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

    PubMed

    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.

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

    PubMed Central

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

    2015-01-01

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

  1. Functional implications of squamosal suture size in paranthropus boisei.

    PubMed

    Dzialo, Christine; Wood, Sarah A; Berthaume, Michael; Smith, Amanda; Dumont, Elizabeth R; Benazzi, Stefano; Weber, Gerhard W; Strait, David S; Grosse, Ian R

    2014-02-01

    It has been hypothesized that the extensively overlapping temporal and parietal bones of the squamosal sutures in Paranthropus boisei are adaptations for withstanding loads associated with feeding. Finite element analysis (FEA) was used to investigate the biomechanical effects of suture size (i.e., the area of overlap between the temporal and parietal bones) on stress, strain energy, and strain ratio in the squamosal sutures of Pan troglodytes and P. boisei (specimen OH 5) during biting. Finite element models (FEMs) of OH 5 and a P. troglodytes cranium were constructed from CT scans. These models contain sutures that approximate the actual suture sizes preserved in both crania. The FEM of Pan was then modified to create two additional FEMs with squamosal sutures that are 50% smaller and 25% larger than those in the original model. Comparisons among the models test the effect of suture size on the structural integrity of the squamosal suture as the temporal squama and parietal bone move relative to each other during simulated premolar biting. Results indicate that with increasing suture size there is a decreased risk of suture failure, and that maximum stress values in the OH 5 suture were favorable compared to values in the Pan model with the normal suture size. Strain ratios suggest that shear is an important strain regime in the squamosal suture. This study is consistent with the hypothesis that larger sutures help reduce the likelihood of suture failure under high biting loads.

  2. Chitin butyrate coated electrospun nylon-6 fibers for biomedical applications

    NASA Astrophysics Data System (ADS)

    Pant, Hem Raj; Kim, Han Joo; Bhatt, Lok Ranjan; Joshi, Mahesh Kumar; Kim, Eun Kyo; Kim, Jeong In; Abdal-hay, Abdalla; Hui, K. S.; Kim, Cheol Sang

    2013-11-01

    In this study, we describe the preparation and characterizations of chitin butyrate (CB) coated nylon-6 nanofibers using single-spinneret electrospinning of blends solution. The physicochemical properties of nylon-6 composite fibers with different proportions of CB to nylon-6 were determined using FE-SEM, TEM, FT-IR spectroscopy, and water contact angle measurement. FE-SEM and TEM images revealed that the nylon-6 and CB were immiscible in the as-spun nanofibers, and phase separated nanofiber morphology becomes more pronounced with increasing amounts of CB. The bone formation ability of composite fibers was evaluated by incubating in biomimetic simulated body fluid. In order to assay the cytocompatibility and cell behavior on the composite scaffolds, osteoblast cells were seeded on the matrix. Results suggest that the deposition of CB layer on the surface of nylon-6 could increase its cell compatibility and bone formation ability. Therefore, as-synthesized nanocomposite fibrous mat has great potentiality in hard tissue engineering.

  3. Degradation of Nylon-6/Clay Nanocomposites in NO(x)

    NASA Astrophysics Data System (ADS)

    Shelley, J. S.; Devries, K. L.

    2000-04-01

    Nylon-6 is an important engineering polymer that, in its fully spherulitic (bulk) form, has many applications in gears, rollers, and other long life cycle components. In 1993, Toyota commercialized a nylon-6/clay nanocomposite out of which it produced the timing belt cover for the 1993 Camry. Although these hybrid nanocomposites show significant improvements in their mechanical response characteristics, including yield strength and heat distortion temperature, little is known about the degradation of these properties due to environmental pollutants like NOx. Nylon-6 fibers are severely degraded by interaction with NOx and other pollutants, showing a strong synergism between applied load and environmental degradation. While the nanocomposites show a significant reduction in permeability of gases and water due to the incorporation of lamellar clay, their susceptibility to non-diffusional mechano-chemical degradation is unknown. The fracture toughness of these nylon-6/day nanocomposites increases, not as a function of clay content, but as a function of the volume of nylon-6 polymer chains influenced by the clay lamellar surfaces. Both the clay and the constrained volume offer the nanocomposites some protection from the deleterious effects of NOx. The time-to-failure at a given stress intensity factor as a function of clay content and constrained volume will be discussed along with fracture toughness of the materials.

  4. Generalized Ferroelectricity in the Mesomorphic Phase of Nylon Polymers

    NASA Astrophysics Data System (ADS)

    Zhang, Zhongbo; Zhu, Lei; Litt, Morton

    Novel ferroelectric polymers, featured by narrow electric displacement-electric (D-E) hysteresis loop, are attractive for electric energy storage applications due to their high dielectric constant and low loss property. Currently, only poly(vinylidene fluoride) (PVDF)-based copolymers (e-beamed) and terpolymers show novel ferroelectric behavior. It is desired to achieve novel ferroelectricity in other polymers such as nylons by carefully modifying the chemical and crystal structures. In this presentation, isomorphic crystals are successfully achieved by copolymerization of nylon 11 and nylon 12 with different compositions. In this way, both chemical and structural defects (i.e., dangling amide groups and kinked bonds) are introduced into the mesomorphic phase. As a consequence, hydrogen bonding interaction is successfully weakened and thus enhanced ferroelectricity with higher maximum polarization and better polarizability is obtained. In addition, for the purpose of further disturbing the mesomorphic phase and pinning effect, partially methylated nylon copolymers are synthesized. With the help of N-methylation of amide groups, the methylated nylon copolymers show relatively narrow hysteresis loops, suggesting the pinning effect from the N-methylated amide moieties.

  5. Discrimination of nylon polymers using attenuated total reflection mid-infrared spectra and multivariate statistical techniques.

    PubMed

    Enlow, Elizabeth M; Kennedy, Jennifer L; Nieuwland, Alexander A; Hendrix, James E; Morgan, Stephen L

    2005-08-01

    Nylons are an important class of synthetic polymers, from an industrial, as well as forensic, perspective. A spectroscopic method, such as Fourier transform infrared (FT-IR) spectroscopy, is necessary to determine the nylon subclasses (e. g., nylon 6 or nylon 6,6). Library searching using absolute difference and absolute derivative difference algorithms gives inconsistent results for identifying nylon subclasses. The objective of this study was to evaluate the usefulness of peak ratio analysis and multivariate statistics for the identification of nylon subclasses using attenuated total reflection (ATR) spectral data. Many nylon subclasses could not be distinguished by the peak ratio of the N-H vibrational stretch to the sp(3) C-H(2) vibrational stretch intensities. Linear discriminant analysis, however, provided a graphical visualization of differences between nylon subclasses and was able to correctly classify a set of 270 spectra from eight different subclasses with 98.5% cross-validated accuracy.

  6. The history and evolution of sutures in pelvic surgery

    PubMed Central

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

    2011-01-01

    Summary The purpose of the study is to review the history and innovations of sutures used in pelvic surgery. Based on a review of the literature using electronic- and hand-searched databases we identified appropriate articles and gynaecology surgical textbooks regarding suture for wound closure. The first documented uses of suture are explored and then the article focuses on the use of knotted materials in pelvic surgery. The development of suture of natural materials is followed chronologically until the present time where synthetic suture is implanted during countless surgeries every day. This millennial history of suture contains an appreciation of the early work of Susruta, Celsus, Paré and Lister, including a survey of some significant developments of suture methods over the last 100 years. Most surgeons know little about the history and science of sutures. A retrospective view of suture is critical to the appreciation of the current work and development of this common tool. PMID:21357979

  7. Fourier technique for studying ammonoid sutures

    SciTech Connect

    Gildner, R.F.; Ackerly, S.C.

    1985-01-01

    Suture patterns have long been recognized as being of primary importance in the study of ammonoids. The authors have developed a technique to use Fourier analysis to study these structures by using a simple transformation: x-y data of a digitized suture are transformed to angle of slope versus position along the suture's length. A Fast Fourier Transform applied to the data produces a power spectrum (amplitude versus wave number) providing a precise and accurate measure of suture shape. The authors have applied this technique to the analysis of ontogenetic change in suture morphology. In goniatitic, ceratitic and preadult ammonitic patterns most of the change is exhibited in the amplitudes of the lowest ten wave numbers. Their Fourier coefficients clearly show trends not readily apparent by visual inspection. The more complex ammonitic patterns are reflected in increased amplitudes of higher wave numbers (a broader peak of the power spectrum) and their analysis is necessarily more complex. The Fourier approach presents the opportunity to quantitatively measure and describe the tempo and mode of evolution in the Ammonoidea. Potential applications of the new technique, as well as limitations, are discussed with special attention to investigations of ammonoid ontogeny and phylogeny.

  8. The cell biology of suturing tendons

    PubMed Central

    Wong, J.K.F.; Alyouha, S.; Kadler, K.E.; Ferguson, M.W.J.; McGrouther, D.A.

    2010-01-01

    Trauma by suturing tendon form areas devoid of cells termed “acellular zones” in the matrix. This study aimed to characterise the cellular insult of suturing and acellular zone formation in mouse tendon. Acellular zone formation was evaluated using single grasping sutures placed using flexor tendons with time lapse cell viability imaging for a period of 12 h. Both tension and injury were required to induce cell death and cell movement in the formation of the acellular zone. DNA fragmentation studies and transmission electron microscopy indicated that cells necrosed. Parallel in vivo studies showed that cell-to-cell contacts were disrupted following grasping by the suture in tensioned tendon. Without tension, cell death was lessened and cell-to-cell contacts remained intact. Quantitative immunohistochemistry and 3D cellular profile mapping of wound healing markers over a one year time course showed that acellular zones arise rapidly and showed no evidence of healing whilst the wound healing response occurred in the surrounding tissues. The acellular zones were also evident in a standard modified “Kessler” clinical repair. In conclusion, the suture repair of injured tendons produces acellular zones, which may potentially cause early tendon failure. PMID:20600895

  9. Immobilization of enzyme on dimethyl-aminated nylon gels

    SciTech Connect

    Miyama, H.; Kawate, M.; Nosaka, Y.

    1985-10-01

    Miyama and co-workers have reported that dimethyl-aminated Nylon is a good material for the immobilization of enzyme after being quaternized. Also, they found a good correlation between the apparent Michaelis constant of the immobilized enzyme and the diffusion constant of the substrate in the matrix, and that between activity of the immobilized enzyme and interfacial free energy of the matrix. In their experiments, Nylon films of low degree of dimethylamination were used. In the present study, dimethylaminated Nylon of high degree of dimethylamination was quaternized by cationic oligomers having two functional groups. Thus, hydrogels were obtained, where the degree of cross-linking and the density of cation could be varied by changing the feeding amount and the length of cross-linking oligomers. These gels were then tested for the immobilization of urease and glucose oxidase. 9 references.

  10. Electrospun fiber and cast films produced using zein blends with nylon-6

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blends of zein and nylon-6 (55k) were used to produce electrospun fibers and solution cast films. Zein was blended with nylon-6 in formic acid solution. When the amount of nylon-6 was 8% or less a compatible blend formed. The blend was determined to be compatible based on physical property measureme...

  11. Electrospun nylon 6 microfiltration membrane for treatment of brewery wastewater

    NASA Astrophysics Data System (ADS)

    Islam, Md. Shahidul; Sultana, Sormin; Rahaman, Md. Saifur

    2016-07-01

    Nylon 6 microfiltration membrane, for the treatment of brewery wastewater, was fabricated using an electrospinning technique, followed by hot-pressing. The fabricated membrane was robust and demonstrated highly hydrophilic property (water contact angle 39° at the touching point to the membrane surface and the water droplet was completely immersed into the membrane in 7 seconds), and higher porosity (65%) with pore sizes of 100 to 210 nm. The electrospun nylon 6 membrane showed higher pure water flux (850 LMH) at an applied pressure of 4 psi. The same membrane also demonstrated a 95% rejection rate of suspended solids (SS) in brewery wastewater treatment.

  12. [Predictable tip suture techniques in rhinoplasty].

    PubMed

    Papel, I D

    2010-09-01

    Recontouring the nasal tip in rhinoplastic procedures has generated a wide range of surgical techniques. These range from aggressive cartilage resection, division, grafting, or suture methods. Each of these categories contains many variations described in hundreds of publications. The goal of this communication is to describe a predictable, reproducible technique that can be used in a wide variety of rhinoplasty operations. Based on pre-existing anatomy variations of this technique can be adopted. The author described the basic technique in 2004 [1].The cornerstone of the technique is a predictable method of narrowing the interdomal space utilizing a suture technique. This procedure employs a pair of permanent sutures designed to minimize distortion, valve impingement and overcorrection. It can be performed through intranasal or external approaches. This paper will define the wide interdomal space, describe the technique, and demonstrate the efficacy of the technique in 250 rhinoplasty procedures. In addition, variations of the technique for specific goals will be shown.

  13. Childhood recurrent pneumonia caused by endobronchial sutures

    PubMed Central

    Zan, Yiheng; Liu, Hanmin; Zhong, Lin; Qiu, Li; Tao, Qingfen; Chen, Lina

    2017-01-01

    Abstract Background: Recurrent pneumonia is defined as more than two episodes of pneumonia in one year or three or more episodes anytime in life. Common clinical scenarios leading to recurrent pneumonia include anatomical abnormalities of respiratory tract, immunodeficiency, congenital heart diseases, primary ciliary dyskinesia, etc. Case report: A school-aged girl suffered from 1-2 episodes of pneumonia each year after trachea connection and lung repair operation resulted from an accident of car crash. Bronchoscopy revealed the sutures twisted with granulation in the left main bronchus and the patient's symptoms relieved after removal of the sutures. Here we report for the first time that surgical suture was the cause of recurrent pneumonia. Conclusions: This case indicates that children with late and recurrent onset of pneumonia should undergo detailed evaluation including bronchoscopy. PMID:28121955

  14. Polypropylene suture--is it safe?

    PubMed

    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.

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

    SciTech Connect

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

    2012-01-02

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

  16. Tissue welding for corneal wound suture with a CW 1.9-um diode laser: an in-vivo preliminary study

    NASA Astrophysics Data System (ADS)

    Desmettre, Thomas; Mordon, Serge R.; Mitchell, Valerie A.

    1996-01-01

    This study aimed to evaluate the interest of a 1.9 micrometer diode laser for corneal wound suture. Six adult albino rabbits were anesthetized. A 7 mm corneal incision was practiced on the right eye. For 3 animals (laser plus stitch) the incision was surgically sutured with 2 stitches of a nylon monofilament and laser impacts were performed between the stitches. For 3 animals (laser only) juxtaposed lasers impacts were realized to suture the wound. After the procedure the animals were examined daily for signs of inflammation, infection and for healing of the corneal wound. Material was obtained for histological examination 1 month after the procedure. Approximation of the edges of the would was successfully obtained in the (laser plus stitch) group. In the (laser only) group this approximation remained troublesome. After the procedure, one cornea of the (laser only) group disclosed a little leakage during 2 days. Histological examination assessed the welding of the corneal wound in the two groups provided structural modifications and some inflammatory signs. Corneal welding using a 1.9 micrometer diode laser is possible either with laser and stitch or with laser only. The approximation of the edges of the wound with additional stitches is an evident drawback. The use of additional stitches should be avoided to keep the theoretical advantages of corneal would suture using laser welding.

  17. Carpet Specifiers Guide. Ultron, Advanced Generation Nylon Carpet Fiber.

    ERIC Educational Resources Information Center

    Monsanto Textiles Co., Atlanta, GA.

    The purpose of this guide is to assist specifiers in properly specifying carpet made of Monsanto Ultron advanced generation nylon fiber. The guide describes a variety of conditions that should be considered in arriving at the proper selection and provides reference information and data, ranging from varying regulatory requirements, performance and…

  18. Nylon shock absorber prevents injury to parachute jumpers

    NASA Technical Reports Server (NTRS)

    Mandel, J. A.

    1966-01-01

    Nylon shock absorbers reduce the canopy-opening shock of a parachute to a level that protects the wearer from injury. A shock absorber is mounted on each of the four risers between the shroud lines and the harness. Because of their size and location, they pose no problem in repacking the chute and harness after a jump.

  19. Carboxybetaine methacrylate oligomer modified nylon for circulating tumor cells capture.

    PubMed

    Dong, Chaoqun; Wang, Huiyu; Zhang, Zhuo; Zhang, Tao; Liu, Baorui

    2014-10-15

    Circulating tumor cells (CTC) capture is one of the most effective approaches in diagnosis and treatment of cancers in the field of personalized cancer medicine. In our study, zwitterionic carboxybetaine methacrylate (CBMA) oligomers were grafted onto nylon via atomic transfer random polymerization (ATRP) which would serve as a novel material for the development of convenient CTC capture interventional medical devices. The chemical, physical and biological properties of pristine and modified nylon surfaces were assessed by Fourier transform infrared spectra, atomic force microscope, water contact angle measurements, X-ray photoelectron spectroscopy, protein adsorption, platelet adhesion, and plasma recalcification time (PRT) determinations, etc. The results, including the significant decrease of proteins adsorption and platelets adhesion, as well as prolonged PRTs demonstrated the extraordinary biocompatibility and blood compatibility of the modified surface. Furthermore, we showed that upon immobilization of anti-epithelial cell adhesion molecular (anti-EpCAM) antibody onto the CBMA moiety, the modified nylon surface can selectively capture EpCAM positive tumor cells from blood with high efficiency, indicating the potential of the modified nylon in the manufacture of convenient interventional CTC capture medical devices.

  20. Achondroplasia with synostosis of multiple sutures.

    PubMed

    Georgoulis, George; Alexiou, George; Prodromou, Neofytos

    2011-08-01

    We report for the second time on a case of achondroplasia with synostosis of multiple sutures. The most common mutation for achondroplasia (FGFR3 Gly380Arg, resulting in 1138G>A) was identified. Imaging studies disclosed complex craniosynostosis and neurosurgical intervention was carried out, particularly for posterior plagiocephaly.

  1. Surgical time for graft preparation using different suture techniques

    PubMed Central

    Camarda, Lawrence; Giambartino, Sebastian; Lauria, Michele; Saporito, Michele; Triolo, Vito; D’Arienzo, Michele

    2016-01-01

    Summary Background The purpose of the present study was to compare the operative time for graft preparation using different techniques for graft suturing. Material and methods Flexor profundus tendons were harvested from fresh pig hind-leg trotters. Three different suture techniques were investigated: the Krackow stitch (K), the Whipstitch (W), and the Modified Finger-Trap suture (MFT). Tendons were sutured starting at 10 mm from the distal free end of the tendon. The suture configurations of the Krackow stitch and Whipstitch were completed with five suture throws. According to the MFT technique, the suture was wrapped five times around the tendon over a distance of 30 mm. The time required to perform a complete suture on each tendon was measured. Five independent examiners of different levels of training measured the time required for graft preparation during 3 separate occasions to determine intraobserver repeatability and interobserver reproducibility. Results The mean time required for graft preparation following the Krackow technique was 69.1 seconds ± 18.3 SD (range 31.8–120). The Whipstitch technique took an average of 59.9 seconds ± 21.2 SD (range 27–93). The MFT suture required a mean of 29.3 seconds ± 11.4 SD for completing the suture (range 21.6–33). In all examiners the time required to complete the MFT suture was significantly less than the other suture techniques (p < 0.05). Intraobserver intraclass correlation coefficients for each examiner ranged from 0.72 to 0.83. Conclusion Low graft preparation time is required to complete a MFT suture in a porcine tendon model. Further, time required for graft preparation using the MFT was shorter than other suturing techniques such as the Krackow and Whipstitch techniques. Clinical relevance The MFT suture could be used for graft set-up with the main advantage of reducing the time required in comparison with other suture techniques. PMID:27900298

  2. Pentachlorophenol sorption in nylon fiber and removal by immobilized Rhizopus oryzae ENHE.

    PubMed

    León-Santiestebán, Hugo; Meraz, Mónica; Wrobel, Kazimierz; Tomasini, Araceli

    2011-06-15

    This study describes pentachlophenol (PCP) sorption in nylon fiber in which Rhizopus oryzae ENHE was immobilized to remove the chemical compound. The experimental sorption data were analyzed using the Langmuir, Freundlich, and Redlich-Peterson isotherm models using non-linear error functions to fit the experimental data to the three models. Results showed that the isotherm obtained from the data fitted the three models used. However, the g parameter from Redlich-Peterson model showed that the isotherm obtained approaches the Freundlich model. This support reached the sorption equilibrium concentration at 3mg PCPg(-1)nylon. To study PCP removal capability by R. oryzae ENHE and to eliminate the error caused by PCP sorbed by the nylon fiber during its quantification, nylon fiber at PCP equilibrium sorption concentration was used to immobilize R. oryzae ENHE. It was found that this fungus grew within nylon fiber cubes in presence or not of PCP, even when PCP caused growth inhibition. Maximum biomass accumulated into nylon cubes without PCP was of 32 mg biomass g(-1)nylon and into nylon cubes at PCP equilibrium concentration was of 18 mg g(-1)nylon. The results showed that R. oryzae ENHE immobilized into nylon fiber removed 88.6% and 92% of PCP in cultures with 12.5 and 25 mg PCPL(-1), as initial concentration, respectively. This is the first work to report that a zygomycete, such as R. oryzae ENHE, immobilized into nylon fiber kept its potential to remove PCP.

  3. Crystalline transformations in nylon-6/single-walled carbon nanotube nanocomposites.

    PubMed

    Naffakh, M; Marco, C; Gómez, M A; Ellis, G; Maser, W K; Benito, A; Martínez, M T

    2009-10-01

    Nylon-6/single-walled carbon nanotube (SWNT) nanocomposites with different SWNTs loadings were prepared by melt-blending. An efficient dispersion of SWNTs into the nylon-6 matrix was confirmed by scanning electron microscopy. DSC and time-resolved synchrotron X-ray diffraction were used to provide detailed information on the effect of SWNTs on the crystalline phase transition of nylon-6 in the nanocomposites. The incorporation of SWNTs accelerated the crystallization rate of nylon-6 due to a nucleating effect. The variable-temperature WAXS experiments, in both neat nylon-6 and nylon-6 nanocomposites, showed that the crystallization from the melt occured through the formation of the pseudo-hexagonal crystal form (gamma) and its transformation to the monoclinic form (alpha) on cooling. Additionally, this crystalline transition was reversible as observed upon heating. The alpha-gamma crystalline transformation temperature of nylon-6 was dependent on heating rate and, more importantly, on the SWNT content.

  4. The role of sutures and fibrin sealant in wound healing.

    PubMed

    Spotnitz, W D; Falstrom, J K; Rodeheaver, G T

    1997-06-01

    Sutures and fibrin sealant are important surgical aids for facilitating wound closure and creating an optimal setting for wound healing. Most commonly, sutures are used to close wounds because suture material provides the mechanical support necessary to sustain closure. A wide variety of suturing material is available, and the surgeon can choose among sutures with a range of attributes to find the one best suited to his or her needs. Considerations when choosing an appropriate suture for wound closure and healing include strength of suture, holding power of tissue, absorbability, risk of infection, and inflammatory reaction associated with the suture material. Other factors to be considered include type of incision, suturing technique, and appearance of wound site. Fibrin sealant, in contrast, is a biologic tissue adhesive that can function as a useful adjunct to sutures. Fibrin sealant can be used in conjunction with sutures or tape to promote optimal wound integrity, or it can be used independently to seal wound sites where sutures cannot control bleeding or would aggravate bleeding. This adhesive can effectively seal tissue planes and eliminate potential spaces. Fibrin sealant has been used clinically in many surgical applications, although an FDA-approved commercially available product does not yet exist in the United States. Clinically, fibrin sealant has resulted in a low rate of infection and has promoted healing. Further study is needed to determine the best fibrin sealant mixtures both to achieve hemostasis and to encourage healing. It may even be desirable to use different sealant formulations for particular clinical situations.

  5. The Morphogenesis of Cranial Sutures in Zebrafish

    PubMed Central

    Topczewska, Jolanta M.; Shoela, Ramy A.; Tomaszewski, Joanna P.; Mirmira, Rupa B.; Gosain, Arun K.

    2016-01-01

    Using morphological, histological, and TEM analyses of the cranium, we provide a detailed description of bone and suture growth in zebrafish. Based on expression patterns and localization, we identified osteoblasts at different degrees of maturation. Our data confirm that, unlike in humans, zebrafish cranial sutures maintain lifelong patency to sustain skull growth. The cranial vault develops in a coordinated manner resulting in a structure that protects the brain. The zebrafish cranial roof parallels that of higher vertebrates and contains five major bones: one pair of frontal bones, one pair of parietal bones, and the supraoccipital bone. Parietal and frontal bones are formed by intramembranous ossification within a layer of mesenchyme positioned between the dermal mesenchyme and meninges surrounding the brain. The supraoccipital bone has an endochondral origin. Cranial bones are separated by connective tissue with a distinctive architecture of osteogenic cells and collagen fibrils. Here we show RNA in situ hybridization for col1a1a, col2a1a, col10a1, bglap/osteocalcin, fgfr1a, fgfr1b, fgfr2, fgfr3, foxq1, twist2, twist3, runx2a, runx2b, sp7/osterix, and spp1/ osteopontin, indicating that the expression of genes involved in suture development in mammals is preserved in zebrafish. We also present methods for examining the cranium and its sutures, which permit the study of the mechanisms involved in suture patency as well as their pathological obliteration. The model we develop has implications for the study of human disorders, including craniosynostosis, which affects 1 in 2,500 live births. PMID:27829009

  6. Recycling Suture Limbs from Knotless Suture Anchors for Arthroscopic Shoulder Stabilization.

    PubMed

    Johnson, Timothy S; DiPompeo, Christine M; Ismaeli, Zahra C; Porter, Polly A; Nicholson, Shannon L; Johnson, David C

    2014-06-01

    Recurrent shoulder instability often leads to labral abnormality that requires surgical intervention that may require fixation with suture anchors. The proposed surgical technique allows the surgeon to achieve 2 points of fixation around the labrum and/or capsule with a single suture secured to the glenoid with a knotless anchor. Instead of cutting and discarding the residual suture limbs after anchor insertion, this technique uses the residual suture limbs of the knotless anchor for a second suture pass. This technique (1) creates a more cost- and time-efficient surgical procedure than using multiple single-loaded anchors or double-loaded anchors, (2) decreases the known risk of glenoid fracture from the stress riser at the implant tips of multi-anchor repairs by reducing the number of anchors required for stabilization, (3) decreases the surgical time compared with the use of double-loaded anchors through simpler suture management and less knot tying, (4) allows for the secure reapproximation of the labrum to the glenoid while offering a convenient option for capsulorrhaphy without the need to insert another anchor, and (5) yields more points of soft-tissue fixation with fewer anchors drilled into the glenoid.

  7. A Comparison of Barbed Sutures and Standard Sutures with regard to Wound Cosmesis in Panniculectomy and Reduction Mammoplasty Patients

    PubMed Central

    Aliano, Kristen; Fromm, Indira Michelle; Dagum, Alexander; Khan, Sami; Bui, Duc

    2016-01-01

    Cosmesis is a vital concern for patients undergoing plastic and reconstructive surgery. Many variations in wound closure are employed when attempting to minimize a surgical scar's appearance. Barbed sutures are one potential method of achieving improved wound cosmesis and are more common in recent years. To determine if barbed sutures differ from nonbarbed in wound cosmesis, we conducted a single-blinded, randomized, controlled trial of 18 patients undergoing bilateral reduction mammoplasty or panniculectomy. Patients were their own controls, receiving barbed sutures on one side and standard sutures on the contralateral side. Surgical scars were evaluated postoperatively by patient preference self-assessment and an observer. Ten patients were evaluated at 3 months postoperatively, yielding a mean Stony Brook Scar Evaluation Scale (SBSES) rating of 4.4 for barbed suture and 3.5 for regular suture (p = 0.15). At 6 months, 8 patients performed self-assessment to determine their preference; 4 preferred the barbed sutures, 1 preferred the regular sutures, and 3 had no preference. Further research with larger sample sizes is needed to determine if barbed sutures convey any advantage over standard sutures in wound healing. However, our results suggest that barbed sutures are a reasonable alternative to standard sutures particularly with regard to wound cosmesis. PMID:28025622

  8. Polyamides based on the renewable monomer, 1,13-tridecane diamine II: Synthesis and characterization of nylon 13,6

    SciTech Connect

    Samanta, Satyabrata; He, Jie; Selvakumar, Sermadurai; Lattimer, Jessica; Ulven, Chad; Sibi, Mukund; Bahr, James; Chisholm, Bret J.

    2012-12-19

    The nylon 13,6 was successfully synthesized and its chemical composition, thermal properties, crystal structure, and moisture absorption characterized. Melting temperature and glass transition temperature were determined to be 206 °C and 60 °C, respectively, while the equilibrium melting temperature was determined to be 248 °C. Characterization of the crystallization kinetics showed that nylon 13,6 exhibits very fast crystallization compared to the industrially important nylons, nylon 6 and nylon 6,6. Additionally, the moisture absorption of nylon 13,6 was dramatically lower than nylon 6 and nylon 6,6 which is consistent with the much lower amide content of nylon 13,6. The crystal structure was determined to be different from the expected γ-form, which possess a pseudohexagonal unit cell. Instead, the x-ray scattering pattern was more similar to the α-form. Furthermore, a similar result has been obtained for other odd–even nylons including nylon 5,6, nylon 5,10, nylon 9,2, nylon 11,10, and nylon 11,12.

  9. Polyamides based on the renewable monomer, 1,13-tridecane diamine II: Synthesis and characterization of nylon 13,6

    DOE PAGES

    Samanta, Satyabrata; He, Jie; Selvakumar, Sermadurai; ...

    2012-12-19

    The nylon 13,6 was successfully synthesized and its chemical composition, thermal properties, crystal structure, and moisture absorption characterized. Melting temperature and glass transition temperature were determined to be 206 °C and 60 °C, respectively, while the equilibrium melting temperature was determined to be 248 °C. Characterization of the crystallization kinetics showed that nylon 13,6 exhibits very fast crystallization compared to the industrially important nylons, nylon 6 and nylon 6,6. Additionally, the moisture absorption of nylon 13,6 was dramatically lower than nylon 6 and nylon 6,6 which is consistent with the much lower amide content of nylon 13,6. The crystal structuremore » was determined to be different from the expected γ-form, which possess a pseudohexagonal unit cell. Instead, the x-ray scattering pattern was more similar to the α-form. Furthermore, a similar result has been obtained for other odd–even nylons including nylon 5,6, nylon 5,10, nylon 9,2, nylon 11,10, and nylon 11,12.« less

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

    SciTech Connect

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

    1988-07-01

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

  11. Ectocranial suture fusion in primates: pattern and phylogeny.

    PubMed

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

    2014-03-01

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

  12. Achondroplasia and multiple-suture craniosynostosis.

    PubMed

    Albino, Frank P; Wood, Benjamin C; Oluigbo, Chima O; Lee, Angela C; Oh, Albert K; Rogers, Gary F

    2015-01-01

    Genetic mutations in the fibroblast growth factor receptor 3 gene may lead to achondroplasia or syndromic forms of craniosynostosis. Despite sharing a common genetic basis, craniosynostosis has rarely been described in cases of confirmed achondroplasia. We report an infant with achondroplasia who developed progressive multiple-suture craniosynostosis to discuss the genetic link between these clinical entities and to describe the technical challenges associated with the operative management.

  13. Suture-induced right coronary artery stenosis.

    PubMed

    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.

  14. Skin tension related to tension reduction sutures.

    PubMed

    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.

  15. Effect of pasteurization, high-pressure processing, and retorting on the barrier properties of nylon 6, nylon 6/ethylene vinyl alcohol, and nylon 6/nanocomposites films.

    PubMed

    Halim, L; Pascall, M A; Lee, J; Finnigan, B

    2009-01-01

    This study determined the impact of pasteurization, high-pressure processing (HPP), and retorting on the barrier properties of nylon 6 (N6), nylon 6/ethylene vinyl alcohol (N6/EVOH), and nylon 6/nanocomposite (N6/nano) materials. The pasteurized and high-pressure treated films were coextruded with low-density polyethylene (PE) as the heat-sealing layer. The retorted films were coextruded with polypropylene (PP). Oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) of the samples were measured after pasteurization (75 degrees C for 30 min), HPP (800 MPa for 10 min at 70 degrees C), and retorting (121 degrees C for 30 min) treatments. These were compared with the thermal characteristics and morphologies of the samples using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Results showed that OTR of N6 and N6/Nano increased after HPP (16.9% and 39.7%), pasteurization (13.3% and 75.9%), and retorting (63.3% and 112.6%), respectively. For N6/EVOH, a decrease in OTR after HPP (53.9%) and pasteurization (44.5%) was observed. The HPP treatment increased the WVTR of N6 (21.0%), N6/EVOH (48.9%), and N6/Nano (21.2%). The WVTR of N6, N6/EVOH, and N6/Nano increased by 96.7%, 43.8%, and 40.7%, respectively, after pasteurization. The DSC analyses showed that the enthalpy and percent crystallinity increased (2.3% to 6.5%) in the N6/Nano when compared with the N6 material after each treatment. Retorting caused a decrease (3.5%) in the percent crystallinity of the polypropylene material. HPP did not cause major morphological changes to the samples. Results of the barrier studies were influenced by the crystallinity changes in the materials as seen in the XRD diffractograms.

  16. Nylon-sputtered nanoparticles: fabrication and basic properties

    NASA Astrophysics Data System (ADS)

    Polonskyi, O.; Kylián, O.; Solař, P.; Artemenko, A.; Kousal, J.; Slavínská, D.; Choukourov, A.; Biederman, H.

    2012-12-01

    Nylon-sputtered nanoparticles were prepared using a simple gas aggregation cluster source based on a planar magnetron (Haberland type) and equipped with a nylon target. Plasma polymer particles originated in an aggregation chamber and travelled to a main (deposition) chamber with a gas flow through an orifice. The deposited nanoparticles were observed to have a cauliflower-like structure. The nanoparticles were found to be nitrogen-rich with N/C ratio close to 0.5. An increase in rf power from 60 to 100 W resulted in a decrease in mean particle size from 210 to 168 nm whereas an increase in their residence time in the cluster source from 0.7 to 4.6 s resulted in an increase in the size from 73 to 231 nm.

  17. Rigid Amorphous Fraction and Lamellar Structure in Nylon-6

    NASA Astrophysics Data System (ADS)

    Chen, Huipeng; Cebe, Peggy

    2007-03-01

    A three-phase model, comprising crystalline, mobile amorphous, and rigid amorphous fractions (RAF) has been applied in the study of semicrystalline Nylon-6. The samples were Nylon-6 alpha phase prepared by subsequent annealing of a parent sample. The samples were annealed at 110^oC, then briefly heated to 136^oC, then re-annealed at 110^oC. Temperature-modulated differential scanning calorimetry measurements allow the devitrification of the rigid amorphous fraction to be examined. We observe a lower endotherm, termed the ``annealing peak'' in the non-reversing heat flow after annealing. By brief heating above this endotherm and immediately quenching, the amount of RAF decrease substantially and the annealing peak disappears. The annealing peak corresponds to the point at which partial de-vitrification of the RAF occurs. None of these treatments affected the measured degree of crystallinity. Using a combined approach of thermal analysis with small angle X-ray scattering, we determine that the Homogeneous Stack Model is the correct one for Nylon-6.

  18. Biofiltration of odorous fume emitted from recycled nylon melting operations.

    PubMed

    Chen, Kuan-Po; Chang, Hsiao-Yu; Chou, Ming-Shean

    2013-11-01

    This study aimed to develop a biofilter packed only with fern chips for the removal of odorous compounds from recycled nylon melting operations. The fern chip biofilters could avoid the shortcomings of traditional media, such as compaction, drying, and breakdown, which lead to the performance failure of the biofilters. A pilot-scale biofilter consisting of an acrylic column (14 cm2 x 120 cm height) packed with fern chips to a volume of around 19.6 L was used for the test. Experimental results indicate that oxygen- and nitrogen-containing hydrocarbons as well as paraffins were major volatile organic compounds (VOCs) emitted from thermal smelting of recycled nylon at 250 degrees C. With operation conditions of medium pH of 5.5-7.0, empty bed retention time (EBRT) of 6-12 sec, influent total hydrocarbon (THC) concentrations of 0.65-2.61 mg m(-3), and volumetric organic loading of 0.05-0.85 g m(-3) hr(-1), the fern-chip-packed biofilter with nutrients of milk, potassium dihydrogen phosphate, and glucose could achieve an overall THC removal efficiency of around 80%. Burnt odor emitted from the smelting of the recycled nylon could be eliminated by the biofilter.

  19. Kinetics for the degradation of nylon and Kevlar parachute materials

    SciTech Connect

    Auerbach, I.

    1986-01-01

    The degradation of nylon 66 and Kevlar 29 yarns at elevated temperatures and over a broad range of humidities was studied and a rate relationship developed which models the degradation and permits computation of rate constants. The degradation rates are slow initially due to the presence of an inhibitor but increase rapidly as the inhibitor is depleted. The effect of relative humidity (RH) can be very large especially at values in the 100% range. An exponential relationship exists for nylon between the rate constant and RH. Kinetic parameters were evaluated and the rate constants at 25/sup 0/C calculated. These values showed that the tensile strength of nylon 66 will remain at a safe level over a 25-year period if the humidity is maintained at the 10% range or less. Kevlar 29 is more resistant and can tolerate humidity levels in the range of 90% or less. Degradation is governed by thermal-oxidative and moisture induced mechanisms. At the very high humidities the moisture induced degradation predominates. A relationship is developed which predicts the degradation rate over a very broad range of temperatures and humidities.

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

    PubMed

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

    2016-05-01

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

  1. Cranial suture biology of the Aleutian Island inhabitants.

    PubMed

    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.

  2. The method of manufacture of nylon dental partially removable prosthesis using additive technologies

    NASA Astrophysics Data System (ADS)

    Kashapov, R. N.; Korobkina, A. I.; Platonov, E. V.; Saleeva, G. T.

    2014-12-01

    The article is devoted to the topic of creating new methods of dental prosthesis. The aim of this work is to investigate the possibility of using additive technology to create nylon prosthesis. As a result of experimental studies, was made a sample of nylon partially removable prosthesis using 3D printing has allowed to simplify, accelerate and reduce the coat of manufacturing high-precision nylon dentures.

  3. Transport Properties of N-Methyloated Nylon-6: Chitosan Blend Membranes

    DTIC Science & Technology

    2006-09-01

    water mixtures via a pervaporation process. In this work, Nylon-6 was methylolated and subsequently blended with chitosan at different compositions...Chitosan/N-methylol Nylon 6 blend Membranes for the Pervaporation Separation of Ethanol–Water Mixtures. Journal of Membrane Science 30 September...Preparation of N-Methylol Nylon-6 Membranes for Pervaporation of Ethanol–Water Mixtures. Journal of Applied Polymer Science 1997, 64 855–863. 6

  4. Development of Polymeric Films with Piezoelectrical Properties from Polypeptides; Low, Odd Nylons; or Polyureas.

    DTIC Science & Technology

    1987-09-01

    PIEZOELECTRICAL PROPERTIES FROM POLYPETIDES; LOW, ODD NYLONS; OR POLYUREAS James P. English -LEC"r David P. Vanderbilt Gerald W. McNeely FEBo0 8 SOUTHERN...Nylons; or Polyureas English, James P.; Vanderbilt, David P.; McNeely, Gerald W. 13a. TYPE OF REPORT 13b TIME COVERED 14. DATE OF REPORT (Year, Month...reverSe if necessary and identify by block number) FIELD GROUP SUB-GROUP ,Piezoelectricity, polyamides, polypeptides, poly (amino acids), polyureas , nylon

  5. The Use of Barbed Sutures in Obstetrics and Gynecology

    PubMed Central

    Greenberg, James A

    2010-01-01

    Despite the multitude of different procedures performed with a host of different wound closure biomaterials, no study or surgeon has yet identified the perfect suture for all situations. In recent years, a new class of suture material—barbed suture—has been introduced into the surgeon’s armamentarium. This review focuses on barbed suture to better understand the role of this newer material in obstetrics and gynecology. PMID:21364859

  6. Needle Path Planning for Autonomous Robotic Surgical Suturing

    PubMed Central

    Jackson, Russell C.; Çavuşoğlu, M. Cenk

    2013-01-01

    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. PMID:24683500

  7. Needle Path Planning for Autonomous Robotic Surgical Suturing.

    PubMed

    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.

  8. Reversing the antilock braking system theory for suture removal.

    PubMed

    Mangus, D J

    1987-06-01

    A simple and extremely practical technique for removal of long subcuticular sutures is possible by simply interposing a rubber band between the suture and the traction source. We have likened the technique in a reverse manner to the pulsing application of brakes in the antilock braking system now commonly found in modern automobiles. We also suggest with this paper that Prolene at this time be tried as the suture of choice in pullout repairs of all types.

  9. Heterochrony and patterns of cranial suture closure in hystricognath rodents

    PubMed Central

    Wilson, Laura A B; Sánchez-Villagra, Marcelo R

    2009-01-01

    Sutures, joints that allow one bone to articulate with another through intervening fibrous connective tissue, serve as major sites of bone expansion during postnatal craniofacial growth in the vertebrate skull and represent an aspect of cranial ontogeny which may exhibit functional and phylogenetic correlates. Suture evolution among hystricognath rodents, an ecologically diverse group represented here by 26 species, is examined using sequence heterochrony methods, i.e. event pairing and parsimov. Although minor nuances in suture closure sequence exist between species, the overall sequence was found to be conserved both across the hystricognath group and, to an increasing degree, within selected clades. At species level, suture closure pattern exhibited a significant positive correlation with patterns previously reported for hominoids. Patterns for most clades revealed the first sutures to close are those contacting the exoccipital, interparietal, and palatine bones. Heterochronic shifts were found along 19 of 35 branches within the hystricognath phylogeny. The number of shifts per node ranged from one to seven events and, overall, involved 21 of 34 suture sites. The topology generated by parsimony analyses of the event pair matrix yielded only one grouping that was congruent with the evolutionary relationships, compiled from morphological and molecular studies, taken as framework. Sutures contacting the exoccipital displayed the highest levels of most complete closure across all species. Level of suture closure is negatively correlated with cranial length (P < 0.05). Differing life history and locomotory strategies are coupled in part with differing suture closure patterns among several species. PMID:19245501

  10. Visual measurement of suture strain for robotic surgery.

    PubMed

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

    2011-01-01

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

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

    SciTech Connect

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

    2013-10-01

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

  12. Validation of the nylon flocked swab for planetary protection applications

    NASA Astrophysics Data System (ADS)

    Moissl-Eichinger, Christine; Probst, Alexander

    The major issue of planetary protection is to prevent the contamination of extraterrestrial en-vironments by terrestrial biomolecules and life forms. In order not to affect or even to confound future life detection missions on celestial bodies, which are of interest for their chemical and bi-ological evolution, spacecraft are constructed in clean rooms and are subject to severe cleaning processes and microbiological controls before launch. Microbiological assays are used to mea-sure and control the bioburden on spacecraft itself and spacecraft hardware during assembly. The current NASA standard assays have originally been developed for the Viking programme in the 70s. Due to the stringent contamination control constrains of the upcoming ESA Ex-oMars mission, these protocols cannot be used, in particular the application of cotton swabs with wooden applicators is no longer possible. Therefore, cotton swabs will be replaced by the novel nylon flocked swabs. In the study presented here, the nylon flocked swabs were validated for the usage for measuring and controling of the bioburden on spacecraft related surfaces. The absolute recovery efficiency was determined, following the guidelines of USP1223 in preci-sion, accuracy, robustness, specificity, linearity and limit of detection. As a standard surface, stainless steel coupons were used, whereas B. atrophaeus (spores) served as standard microbial strain. Additionally, the nylon flocked swab was used for experiments on different rough and smooth surfaces with seven different Bacillus spores and two different protocols. Further details will be given concerning the new ESA standard swab procedure for the microbial examination of flight hardware and clean rooms to be used for the upcoming ExoMars mission.

  13. New suture materials for midline laparotomy closure: an experimental study

    PubMed Central

    2014-01-01

    Background Midline laparotomy closure carries a significant risk of incisional hernia. This study examines the behavior of two new suture materials, an elastic material, polyurethane (PUe), and a barbed polydioxanone (PDXb) suture thread in a rabbit model of midline incision closure. Methods Three 2-cm midline incisions were made in 68 New Zealand White rabbits. The incisions were closed by running suture using four 3/0 threads: polypropylene (PP) (Surgipro®, Covidien), PUe (Assuplus®, Assut Europe), PDX (Assufil®, Assut Europe) or PDXb (Filbloc®, Assut Europe). Animals in each suture group were euthanized 3 weeks and 6 months after surgery. Histological sections of the tissue-embedded sutures were subjected to morphological, collagen expression, macrophage response and uniaxial tensiometry studies. Results No signs of wound dehiscence or complications were observed. At 3 weeks, all sutures were surrounded by connective tissue composed mainly of collagen III. PUe showed greater collagen I expression than the other sutures. All sutures elicited a macrophage response that diminished from 3 weeks to 6 months (p < 0.001). This response was similar for the non-reabsorbable sutures (PP and PUe) yet PDXb showed a significantly greater response than the other reabsorbable suture (PDX) at 3 weeks (p < 0.01). At this early time point, the tensile strength of PUe was similar to that of control intact tissue (p > 0.05). Conclusion Three weeks after surgery, PUe revealed more collagen I deposition than the remaining materials and this translated to a similar biomechanical behavior to linea alba, that could avoid the appearance of short term dehiscences and thus reduce the incidence of incisional hernia. PDXb provides no additional advantages in their behavior regarding PDX suture. PMID:25231161

  14. Low background techniques for the Borexino nylon vessels

    SciTech Connect

    Pocar, Andrea

    2005-09-08

    Borexino is an organic liquid scintillator underground detector for low energy solar neutrinos. The experiment has to satisfy extremely stringent low background requirements. The thin nylon spherical scintillator containment vessel has to meet cleanliness and low radioactivity levels second only, within the detector, to the scintillator itself. Overall, the background from the vessel in the fiducial volume of the detector must be kept at the level of one event per day or better. The requirements, design choices, results from laboratory tests, and fabrication techniques that have been adopted to meet this goal are presented. Details of the precautions taken during the installation of the vessels inside the Borexino detector are also discussed.

  15. Nylon membrane as a fluorimetric probe for the herbicide bentazone.

    PubMed

    Chiarandini, Jessica P; Escandar, Graciela M

    2012-02-01

    The fluorimetric signal produced by bentazone retained in selected solid surfaces was investigated. Among the different tested supports, only a microporous nylon membrane produced the desired signal. The quantitative study was carried out by second-order calibration using parallel factor analysis, allowing the determination in a highly interfering medium. A detection limit of 0.4 ng mL(-1), a prediction relative error of 8%, and a sample frequency of ten samples per hour were obtained in spiked natural waters using green analytical chemistry principles.

  16. Nylon-3 polymers that enable selective culture of endothelial cells.

    PubMed

    Liu, Runhui; Chen, Xinyu; Gellman, Samuel H; Masters, Kristyn S

    2013-11-06

    Substrates that selectively encourage the growth of specific cell types are valuable for the engineering of complex tissues. Some cell-selective peptides have been identified from extracellular matrix proteins; these peptides have proven useful for biomaterials-based approaches to tissue repair or regeneration. However, there are very few examples of synthetic materials that display selectivity in supporting cell growth. We describe nylon-3 polymers that support in vitro culture of endothelial cells but do not support the culture of smooth muscle cells or fibroblasts. These materials may be promising for vascular biomaterials applications.

  17. Safety assessment of nylon as used in cosmetics.

    PubMed

    Burnett, Christina; Heldreth, Bart; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2014-01-01

    The Cosmetic Ingredient Review Expert Panel (Panel) reviewed the safety of nylon polymers, which function in cosmetics primarily as bulking and opacifying agents. The Panel reviewed relevant animal and human data related to these large polymers and determined that they are not likely to penetrate the skin. Whatever residual monomers may be present were not present at a sufficient level to cause any reactions in test subjects at the maximum ingredient use concentration. Accordingly, the Panel concluded that these ingredients are safe in the present practices of use and concentration.

  18. Development of rapid continuous dyeing process for heavy-weight nylon 6,6 carpet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An improved continuous dyeing process for coloration of heavy-weight (60-70 oz/yd2), residential nylon 6,6 carpet is reported. By inserting a slot steam applicator after the dye pad and before the box steamer to preheat the carpet to around 180°F (greater than the nylon wet glass transition temperat...

  19. 21 CFR 175.360 - Vinylidene chloride copolymer coatings for nylon film.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... film. 175.360 Section 175.360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... coatings for nylon film. Vinylidene chloride copolymer coatings identified in this section and applied on nylon film may be safely used as food-contact surfaces, in accordance with the following...

  20. 21 CFR 175.360 - Vinylidene chloride copolymer coatings for nylon film.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... film. 175.360 Section 175.360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... Use as Components of Coatings § 175.360 Vinylidene chloride copolymer coatings for nylon film. Vinylidene chloride copolymer coatings identified in this section and applied on nylon film may be...

  1. 21 CFR 175.360 - Vinylidene chloride copolymer coatings for nylon film.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... film. 175.360 Section 175.360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... coatings for nylon film. Vinylidene chloride copolymer coatings identified in this section and applied on nylon film may be safely used as food-contact surfaces, in accordance with the following...

  2. [Effect of carbon nanotubes on the crystallization behaviors of MC nylon 6].

    PubMed

    Qiu, Shang-Chang; Zheng, Yu-Ying; Zeng, An-Ran; Guo, Yong

    2011-09-01

    Multi-walled carbon nanotubes bearing hydroxyl group were modified with toluene diisocyanate (TDI) and stabilized with caprolactam. The functionalized carbon nanotubes were used to prepare monomer casting polyamide 6(MC nylon 6)/carbon nanotubes nanocomposites. The results of FTIR proved that isocynate groups have been incorporated into carbon nanotubes successfully. XRD results showed that the addition of the functionalized carbon nanotubes has no significant influence on the crystal structure of MC nylon 6, whereas the untreated carbon nanotubes could hinder the growth of alpha2-crystal of nylon 6; with the loading of 0.3 Wt% of the functionalized carbon nanotubes, the crystallinity degree of the nanocomposites is almost equal to that of pure MC nylon 6, whereas as the loading increased to 0.5 Wt%, the crystallinity degree of MC nylon 6 decreased. DSC revealed that carbon nanotubes in MC nylon 6 acted as effective nucleation agents. The peak temperature of crystallization for MC nylon 6 increased by 10 degrees C from 173.4 to 183.5 degrees C, and the temperature range of crystallization decreased, indicating that the carbon nanotubes act as heterogeneous nucleation agents for MC nylon 6.

  3. The use of nylon cable ties to repair rib fractures in neonatal foals.

    PubMed

    Downs, Chris; Rodgerson, Dwayne

    2011-03-01

    Commercially available nylon cable ties were used as a method of internal fixation for displaced rib fractures in 8 equine neonates. The procedure was effective, well-tolerated, rapid, and inexpensive. The use of nylon cable ties as internal fixation for displaced rib fractures in foals is an effective surgical procedure.

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

    SciTech Connect

    Muttaqien, Fahdzi Suprijadi

    2015-04-16

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

  5. Evaluation of overcharge protection life in nickel cadmium cells with non-nylon separators

    SciTech Connect

    Scoles, D.L.; Johnson, Z.W.; Hayden, J.W.; Pickett, D.F. Jr.

    1997-12-01

    Hydrogen gassing and the potential for cell rupture in aerospace nickel cadmium cells is directly related to loss of overcharge protection built into the cell during manufacturing. It is well known that cells having nylon separators contribute to this loss via a hydrolysis reaction of the nylon in the potassium hydroxide electrolyte environment in the cell. The hydrolysis reaction produces lower chain organics which are oxidized by the positive electrode and oxygen. Oxidation of the organics diminishes the overcharge protection. With introduction of the Super NiCd and the Magnum nickel cadmium cells the nylon hydrolysis reaction is eliminated, but any reducing agent in the cell such as nickel or an organic additive can contribute to loss of overcharge protection. The present effort describes analyses made to evaluate the extent of overcharge protection loss in cells which do not have nylon hydrolysis and quantifies the diminished amount of overcharge protection loss as a result of eliminating nylon from aerospace cells.

  6. Manufacture and characterization of silver and copper nanostructures produced via forcespun Nylon 6 nanofibers

    NASA Astrophysics Data System (ADS)

    Zhao, Wenqian

    Nylon 6 nanofibers were produced using the ForcespinningRTM method and were deposited with silver or copper thin films using the high vacuum thermal evaporation technique for surface functionalization of nanostructures. The changes in surface composition, morphology and surface energy of native and metallic coated Nylon 6 nanofibers were examined. Their antibacterial properties of native, silver or copper coated Nylon 6 nanofibers were tested. Furthermore, the Nylon 6 nanofibers were used as templates in order to obtain silver or copper nanotubes where the polymer was removed after high temperature calcination. The metallic coated Nylon 6 nanofibers and metallic nanotubes morphology and electrical behavior are characterized using the SEM, STEM, XRD, EDS and electrical measurements.

  7. Multifunctional ZnO/Nylon 6 nanofiber mats by an electrospinning– electrospraying hybrid process for use in protective applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning–electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacter...

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

    PubMed

    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.

  9. Interdomal Suture through a Nondelivery Endonasal Approach: A New Technique

    PubMed Central

    Leibou, Lior

    2016-01-01

    Background: The use of interdomal sutures for tip refinement is common in open rhinoplasty and in endonasal rhinoplasty using a delivery technique, but there is paucity of reports in the literature regarding the use of interdomal suturing techniques when the nondelivery endonasal approach is chosen. Objective: The authors describe a technique designed to refine the nasal tip with an interdomal suture placed through a nondelivery endonasal approach. Methods: In this study, the authors retrospectively review the cases of 45 patients who underwent endonasal rhinoplasty with the authors’ interdomal suturing technique between the years 2011 and 2013. The average age of the patients was 25.3 years. Intercrural sutures (PDS 4.0 straight needle, Cincinnati, Ohio) were placed as mattress-like suture in the tip region, with the knot buried between both alar cartilages. The suture is tightened progressively according to the tip definition and narrowing sought. Results: The patients were followed for 12 months. All of the patients demonstrated a significant reduction in lobule and tip widths. This series had only 1 complication of tip asymmetry that was revised 1 year after the initial operation. There were no cases of infection, allergic reaction, or extrusion of the suture. Conclusions: Despite the lack of a large volume of patients, our study confirms that this technique is indeed an attractive and highly predictable option for achieving adequate tip refinement and definition when using a nondelivery endonasal rhinoplasty. PMID:27622086

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

    PubMed Central

    Gassner, Holger G.

    2011-01-01

    Rhinoplasty has undergone important changes. With the advent of the open structure approach, requirements for structural grafting and direct manipulation of the cartilaginous skeleton through suture techniques have increased substantially. The present review analyzes the current literature on frequently referenced structural grafts and suture techniques. Individual techniques are described and their utility is discussed in light of available studies and data. PMID:22073105

  11. Cataract Section Across Temporary Stainless-Steel Sutures

    PubMed Central

    MacDonald, R. Keith

    1965-01-01

    The purpose of the technique described was to combine the advantages of a cleanedged Graefe-knife incision with those of safety and near-perfect apposition offered by preplaced sutures: a preliminary to cataract extraction. Uncuttable preplaced 2-mm. stainless steel sutures were finally replaced after completion of the incision by attached braided silk for closure purposes. PMID:14291461

  12. 21 CFR 882.4650 - Neurosurgical suture needle.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Neurosurgical suture needle. 882.4650 Section 882.4650 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4650 Neurosurgical suture...

  13. 21 CFR 882.4650 - Neurosurgical suture needle.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Neurosurgical suture needle. 882.4650 Section 882.4650 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4650 Neurosurgical suture...

  14. 21 CFR 882.4650 - Neurosurgical suture needle.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Neurosurgical suture needle. 882.4650 Section 882.4650 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4650 Neurosurgical suture...

  15. 21 CFR 882.4650 - Neurosurgical suture needle.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Neurosurgical suture needle. 882.4650 Section 882.4650 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4650 Neurosurgical suture...

  16. 21 CFR 882.4650 - Neurosurgical suture needle.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neurosurgical suture needle. 882.4650 Section 882.4650 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4650 Neurosurgical suture...

  17. Nose tip refinement using interdomal suture in caucasian nose

    PubMed Central

    Pasinato, Rogério; Mocelin, Marcos; Berger, Cezar Augusto Sarraf

    2012-01-01

    Summary Introduction: Refinement of the nose tip can be accomplished by a variety of techniques, but currently, the use of sutures in the nasal tip with conservative resection of the alar cartilage is the most frequently recommended approach. Objective: To classify the nasal tip and to demonstrate the interdomal suture applied to nasal tip refinement in the Caucasian nose, as well as to provide a simple and practical presentation of the surgical steps. Method: Development of surgical algorithm for nasal tip surgery: 1. Interdomal suture (double binding suture), 2. Interdomal suture with alar cartilage weakening (cross-hatching), 3. Interdomal suture with cephalic removal of the alar cartilage (McIndoe technique) based on the nasal tip type classification. This classification assesses the interdomal distance (angle of domal divergence and intercrural distance), domal arch width, cartilage consistency, and skin type. Interdomal suture is performed through endonasal rhinoplasty by basic technique without delivery (Converse-Diamond technique) under local anesthesia. Conclusion: This classification is simple and facilitates the approach of surgical treatment of the nasal tip through interdomal suture, systematizing and standardizing surgical maneuvers for better refinement of the Caucasian nose. PMID:25991963

  18. 21 CFR 878.4930 - Suture retention device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Suture retention device. 878.4930 Section 878.4930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4930 Suture retention...

  19. 21 CFR 878.4930 - Suture retention device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Suture retention device. 878.4930 Section 878.4930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4930 Suture retention...

  20. 21 CFR 878.4930 - Suture retention device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Suture retention device. 878.4930 Section 878.4930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4930 Suture retention...

  1. 21 CFR 878.4930 - Suture retention device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Suture retention device. 878.4930 Section 878.4930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4930 Suture retention...

  2. 21 CFR 878.4930 - Suture retention device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Suture retention device. 878.4930 Section 878.4930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4930 Suture retention...

  3. Biomechanical evaluation of tibial eminence fractures using suture fixation.

    PubMed

    Aoki, Stephen K; Curtis, Stuart H

    2011-12-06

    This study evaluates the initial fixation strength of tibial eminence fracture repair using 1, 2, 3, and 4 sutures to determine the optimal number of sutures required to adequately secure the avulsed fragment to the tibia. Sixteen skeletally immature porcine knees were stripped of all soft tissues, isolating the femur-anterior cruciate ligament (ACL)-tibia complex. Type III tibial eminence fractures were simulated in the specimens, and each specimen was randomly assigned to a repair group using 1, 2, 3, or 4 #2 FiberWire sutures (Arthrex, Inc, Naples, Florida). Initial fixation strength of the repair was measured by single cycle pull to failure testing using a materials testing machine (Instron, Norwood, Massachusetts). The mean ultimate failure force during anterior tibial translation was 389±128, 627±66, 703±77, and 802±29 N for 1, 2, 3, and 4 sutures, respectively. The lower limit of the 95% confidence interval was >500 N (estimated force of native ACL during activities of daily living) for each group with ≥2 sutures. In this study, at least 2 high-strength sutures were needed for tibial eminence fracture repairs to withstand potential forces seen across the ACL in the postoperative period. Suture fixation of tibial eminence fractures is a reproducible method requiring a minimum of 2 high-strength polyester sutures to resist forces seen during early rehabilitation.

  4. Ferroelectric behavior of the odd-numbered nylons

    SciTech Connect

    Scheinbeim, J.I.; Newman, B.A.

    1993-12-31

    Recent work in the Polymer Electroprocessing Laboratory. Rutgers University, has shown that the odd-numbered nylons (11, 9, 7, 5) constitute the second known family of ferroelectric polymers: poly(vinylidene fluoride) and its co-polymers are the only other known family of ferroelectric polymers. Using mel-quenched and cold-drawn samples of nylon 11 which exhibit double orientation (chain axes in the draw direction and hydrogen bonds in the plane of the films) the authors examined changes in orientation of the polar (hydrogen bonds) and non-polar (hydrocarbon) sections as a function of annealing temperature and applied electric field. Using FTIR and WAXD studies, the authors have found that the samples polarized by application of electric fields before high temperature annealing exhibit diffraction patterns rotated by 90{degrees} from those of samples exposed to only high temperature annealing. These studies also show that the polarized, annealed samples are triply oriented and that they hydrocarbon sections exhibit little crystal order unless samples are annealed at high temperature.

  5. Loss of fine particle ammonium from denuded nylon filters

    NASA Astrophysics Data System (ADS)

    Yu, Xiao-Ying; Lee, Taehyoung; Ayres, Benjamin; Kreidenweis, Sonia M.; Malm, William; Collett, Jeffrey L.

    Ammonium is an important constituent of fine particulate mass in the atmosphere, but can be difficult to quantify due to possible sampling artifacts. Losses of semivolatile species such as NH 4NO 3 can be particularly problematic. In order to evaluate ammonium losses from aerosol particles collected on filters, a series of field experiments was conducted using denuded nylon and Teflon filters at Bondville, IL (February 2003), San Gorgonio, CA (April 2003 and July 2004), Grand Canyon NP, AZ (May, 2003), Brigantine, NJ (November 2003), and Great Smoky Mountains National Park (NP), TN (July-August 2004). Samples were collected over 24 h periods. Losses from denuded nylon filters ranged from 10% (monthly average) in Bondville, IL to 28% in San Gorgonio, CA in summer. Losses on individual sample days ranged from 1% to 65%. Losses tended to increase with increasing diurnal temperature and relative humidity changes and with the fraction of ambient total N(-III) (particulate NH 4++gaseous NH 3) present as gaseous NH 3. The amount of ammonium lost at most sites could be explained by the amount of NH 4NO 3 present in the sampled aerosol. Ammonium losses at Great Smoky Mountains NP, however, significantly exceeded the amount of NH 4NO 3 collected. Ammoniated organic salts are suggested as additional important contributors to observed ammonium loss at this location.

  6. Loss of Fine Particle Ammonium from Denuded Nylon Filters

    SciTech Connect

    Yu, Xiao-Ying; Lee, Taehyoung; Ayres, Benjamin; Kreidenweis, Sonia M.; Malm, William C.; Collett, Jeffrey L.

    2006-08-01

    Ammonium is an important constituent of fine particulate mass in the atmosphere, but can be difficult to quantify due to possible sampling artifacts. Losses of semivolatile species such as NH4NO3 can be particularly problematic. In order to evaluate ammonium losses from aerosol particles collected on filters, a series of field experiments was conducted using denuded nylon and Teflon filters at Bondville, Illinois (February 2003), San Gorgonio, California (April 2003 and July 2004), Grand Canyon National Park, Arizona (May, 2003), Brigantine, New Jersey (November 2003), and Great Smoky Mountains National Park (NP), Tennessee (July–August 2004). Samples were collected over 24-hr periods. Losses from denuded nylon filters ranged from 10% (monthly average) in Bondville, Illinois to 28% in San Gorgonio, California in summer. Losses on individual sample days ranged from 1% to 65%. Losses tended to increase with increasing diurnal temperature and relative humidity changes and with the fraction of ambient total N(--III) (particulate NH4+ plus gaseous NH3) present as gaseous NH3. The amount of ammonium lost at most sites could be explained by the amount of NH4NO3 present in the sampled aerosol. Ammonium losses at Great Smoky Mountains NP, however, significantly exceeded the amount of NH4NO3 collected. Ammoniated organic salts are suggested as additional important contributors to observed ammonium loss at this location.

  7. Nylon coil actuator operating temperature range and stiffness

    NASA Astrophysics Data System (ADS)

    Kianzad, Soheil; Pandit, Milind; Bahi, Addie; Rafie Ravandi, Ali; Ko, Frank; Spinks, Geoffrey M.; Madden, John D. W.

    2015-04-01

    Components in automotive and aerospace applications require a wide temperature range of operation. Newly discovered thermally active Baughman muscle potentially provides affordable and viable solutions for driving mechanical devices by heating them from room temperature, but little is known about their operation below room temperature. We study the mechanical behavior of nylon coil actuators by testing elastic modulus and by investigating tensile stroke as a function of temperature. Loads that range from 35 MPa to 155 MPa were applied. For the nylon used and the coiling conditions, active thermal contraction totals 19.5 % when the temperature is raised from -40 °C to 160 °C. The thermal contraction observed from -40 °C to 20°C is only ~2 %, whereas between 100 and 160 °C the contraction is 10 %. A marked increase in thermal contraction is occurs in the vicinity of the glass transition temperature (~ 45°C). The elastic modulus drops as temperature increases, from ~155 MPa at - 40 °C to 35 MPa at 200 °C. Interestingly the drop in active contraction with increasing load is small and much less than might be expected given the temperature dependence of modulus.

  8. Sulfide oxidation in fluidized bed bioreactor using nylon support material.

    PubMed

    Midha, Varsha; Jha, M K; Dey, Apurba

    2012-01-01

    A continuous fluidized bed bioreactor (FBBR) with nylon support particles was used to treat synthetic sulfide wastewater at different hydraulic retention time of 25, 50 and 75 min and upflow velocity of 14, 17 and 20 m/hr. The effects of upflow velocity, hydraulic retention time and reactor operation time on sulfide oxidation rate were studied using statistical model. Mixed culture obtained from the activated sludge, taken from tannery effluent treatment plant, was used as a source for microorganisms. The diameter and density of the nylon particles were 2-3 mm and 1140 kg/m3, respectively. Experiments were carried out in the reactor at a temperature of (30 +/- 2) degrees C, at a fixed bed height of 16 cm after the formation of biofilm on the surface of support particles. Biofilm thickness reached (42 +/- 3) microm after 15 days from reactor start-up. The sulfide oxidation, sulfate and sulfur formation is examined at all hydraulic retention times and upflow velocities. The results indicated that almost 90%-92% sulfide oxidation was achieved at all hydraulic retention times. Statistical model could explain 94% of the variability and analysis of variance showed that upflow velocity and hydraulic retention time slightly affected the sulfide oxidation rate. The highest sulfide oxidation of 92% with 70% sulfur was obtained at hydraulic retention time of 75 min and upflow velocity of 14 m/hr.

  9. HVOF-Sprayed Nylon-11 + Nanodiamond Composite Coatings: Production & Characterization

    NASA Astrophysics Data System (ADS)

    Stravato, A.; Knight, R.; Mochalin, V.; Picardi, S. C.

    2008-12-01

    High velocity oxy-fuel (HVOF) combustion spraying has previously been shown to be a viable method for depositing polymer and polymer/ceramic composite coatings. The addition of hard particulate reinforcing phases to soft polymeric matrices should improve their durability and sliding wear performance. Nanosized diamond is an ideal reinforcing phase, owing to its high hardness, low coefficient of friction, and desirable thermal properties. Composite coatings comprising a Nylon-11 matrix reinforced with nanodiamonds have been successfully produced by HVOF. An important challenge is preserving the structure of the nanoparticles after thermal spray deposition and achieving their uniform dispersion within the polymeric matrix. Raman spectroscopy and x-ray diffraction were used to confirm the presence and retention of nanodiamonds after HVOF deposition. Understanding of the role of process parameters, including the content of reinforcing phase in the matrix and powder preparation route is necessary. Nanoindentation studies demonstrated an improvement in creep behavior and recovery of the HVOF Nylon-11/nanodiamond composites subjected to deformation.

  10. Strain in the Braincase and Its Sutures During Function

    PubMed Central

    Herring, Susan W.; Teng, Shengyi

    2010-01-01

    The skull is distinguished from other parts of the skeleton by its composite construction. The sutures between bony elements provide for interstitial growth of the cranium, but at the same time they alter the transmission of stress and strain through the skull. Strain gages were bonded to the frontal and parietal bones of miniature pigs and across the interfrontal, interparietal and coronal sutures. Strains were recorded 1) during natural mastication in conjunction with electromyographic activity from the jaw muscles and 2) during stimulation of various cranial muscles in anesthetized animals. Vault sutures exhibited vastly higher strains than did the adjoining bones. Further, bone strain primarily reflected torsion of the braincase set up by asymmetrical muscle contraction; the tensile axis alternated between +45° and −45° depending on which diagonal masseter/temporalis pair was most active. However, suture strains were not related to overall torsion but instead were responses to local muscle actions. Only the coronal suture showed significant strain (tension) during jaw opening; this was caused by the contraction of neck muscles. All sutures showed strain during jaw closing, but polarity depended on the pattern of muscle usage. For example, masseter contraction tensed the coronal suture and the anterior part of the interfrontal suture, whereas the temporalis caused compression in these locations. Peak tensile strains were larger than peak compressive strains. Histology suggested that the skull is bent at the sutures, with the ectocranial surface tensed and the endocranial surface predominantly compressed. Collectively, these results indicate that skulls with patent sutures should be analyzed as complexes of independent parts rather than solid structures. PMID:10918130

  11. Tuning the mechanical properties of SWNT/nylon 6,10 composites with flexible spacers at the interface.

    PubMed

    Moniruzzaman, Mohammad; Chattopadhyay, Jayanta; Billups, W Edward; Winey, Karen I

    2007-05-01

    We have prepared nylon 6,10 nanocomposites using functionalized single wall carbon nanotubes and our interfacial in situ polycondensation method. The specific functional groups -(CH2)nCOCl [n = 4 and 9] on the sidewalls of SWNT were designed to covalently link nanotubes to the nylon matrix via alkyl segments. The composites with functionalized SWNT show significant improvements in tensile modulus, strength, and toughness relative to nylon and nylon modified with non-functionalized SWNT. The alkyl linkages at the SWNT/nylon 6,10 interface contribute significantly to improving the toughness of the composites.

  12. Microbiological Evaluation of Suture Items Before Radiation Sterilization

    PubMed Central

    Österberg, Bertil O.

    1973-01-01

    Microbiological contamination levels of suture samples taken at various stages of the manufacturing process in a new hygienically controlled plant were determined by employing a membrane filturation technique. Both raw material and materials handled manually in the production process were tested to assess the effect of manual handling on the product contamination level. Evaluation of the efficacy of contamination control, however, was directed primarily to the finished, packaged products, just prior to the processing with cobalt 60. The suture material for testing was divided into two groups, namely, wet and dry products, the wet being packaged in a special „tubing” fluid consisting mainly of isopropyl alcohol. Initial contamination results are reported as the average of values obtained on the test day and the preceding 9 consecutive production days. A total of 1,787 suture samples tested in the dry group showed daily averages varying between 2.1 and 14.8 contaminants per suture. The 2,980 wet-packaged suture samples tested gave daily averages varying from 0.7 to 4.2 contaminants per suture. The highest values obtained for an individual suture were 400 for the dry and 89 for the wet. Identification studies of the contaminants revealed that fungi predominated. Most of the bacterial contaminants proved to be spore-forming rods. PMID:4751791

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

    PubMed

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

    2013-10-01

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

  14. Barbed suture for gastrointestinal closure: a randomized control trial.

    PubMed

    Demyttenaere, Sebastian V; Nau, Peter; Henn, Matthew; Beck, Catherine; Zaruby, Jeffrey; Primavera, Michael; Kirsch, David; Miller, Jeffrey; Liu, James J; Bellizzi, Andrew; Melvin, W Scott

    2009-09-01

    In an effort to make laparoscopic suturing more efficient, the V-Loc advanced wound closure device (Covidien, Mansfield, MA) has been produced. This device is a self-anchoring barbed suture that obviates the need for knot tying. The goal of this initial feasibility study was to investigate the use of the barbed suture in gastrointestinal enterotomy closure. A randomized study of 12 pigs comparing enterotomy closure with barbed versus a nonbarbed suture of similar tensile strength was performed. To this end, 25 mm enterotomies were made in the stomach (1 control, 1 treatment), jejunum (2 controls, 2 treatments), and descending colon (1 control, 1 treatment). Animals were killed at 3, 7, and 14 days postoperatively (4 each group) and their gastrointestinal tracts harvested; 6 of the 8 enterotomies from each pig underwent burst strength testing. The remaining 2 were fixed in formalin and sent for histological examination. All 12 pigs survived until they were killed without any major complications. Enterotomy closure with barbed suture revealed adhesion scores, burst strength pressures, and histology scores that were similar to those for the control. Jejunal closures resulted in 6 failures at 7 days (3 control, 3 barbed) and 4 failures at 14 days (2 control, 2 barbed). The barbed suture significantly reduced suturing time in the stomach, jejunum, and colon. The V-Loc wound closure device appears to offer comparable gastrointestinal closure to 3-0 Maxon while being significantly faster. Further studies with V-Loc are required to assess its use in laparoscopic surgery.

  15. Preparation of a novel KCC-1/nylon 6 nanocomposite via electrospinning technique

    NASA Astrophysics Data System (ADS)

    Aghakhani, Ali; Kazemi, Ensiyeh; Kazemzad, Mahmood

    2015-10-01

    In this research, a novel nanofibrous composite of KCC-1/nylon 6 was prepared using electrospinning techniques. First, fibrous silica nanospheres (KCC-1) were synthesized via conventional polycondensation method with a new solvent system. The scanning electron microscopy (SEM) images showed a spongy spherical morphology with a uniform distribution of particle sizes and an average diameter of around 305 nm. Synthesized KCC-1 nanospheres are considered as mesoporous materials due to their high BET specific surface area of 576 m2 g-1 and BJH average pore diameter of 3.28 nm. The KCC-1/nylon 6 composite was fabricated by preparing a dispersion of nanosilica (10-50 % w/w) in a solution of nylon 6 (15 % w/v) in formic acid. Upon applying a high voltage, the nonwoven electrospun KCC-1/nylon 6 composite nanofibers were obtained. The KCC-1 nanospheres were arranged in line along the nylon 6 fibers like rosary beads wrapped in the polymer. Based on the SEM images, we obtained a well-distributed nanocomposite even at higher silica content. The prepared KCC-1/nylon 6 composite showed 29-55 % higher BET specific surface area compared with pure nylon 6 nanofibers which makes it a good candidate to be used as a sorbent material for environmental or drug delivery applications.

  16. Physio-chemical and antibacterial characteristics of pressure spun nylon nanofibres embedded with functional silver nanoparticles.

    PubMed

    Xu, Z; Mahalingam, S; Rohn, J L; Ren, G; Edirisinghe, M

    2015-11-01

    A novel and facile approach to prepare hybrid nanoparticle embedded polymer nanofibers using pressurised gyration is presented. Silver nanoparticles and nylon polymer were used in this work. The polymer solution's physical properties, rotating speed and the working pressure had a significant influence on the fibre diameter and the morphology. Fibres in the range of 60-500nm were spun using 10wt.%, 15wt.% and 20wt.% nylon solutions and these bead-free fibres were processed under 0.2MPa and 0.3MPa working pressure and a rotational speed of 36,000rpm. 1-4wt.% of Ag was added to these nylon solutions and in the case of wt.% fibres in the range 50-150nm were prepared using the same conditions of pressurised gyration. Successful incorporation of the Ag nanoparticles in nylon nanofibres was confirmed by using a combination of advanced microscopical techniques and Raman spectrometry was used to study the bonding characteristics of nylon and the Ag nanoparticles. Inductively coupled plasma mass spectroscopy showed a substantial concentration of Ag ions in the nylon fibre matrix which is essential for producing effective antibacterial properties. Antibacterial activity of the Ag-loaded nanofibres shows higher efficacy than nylon nanofibres for Gram-negative Escherichia coli and Pseudomonas aeruginosa microorganisms, and both Ag nanoparticles and the Ag ions were found to be the reason for enhanced cell death in the bacterial solutions.

  17. Adsorption of papain with Cibacron Blue F3GA carrying chitosan-coated nylon affinity membranes.

    PubMed

    Nie, Hua-Li; Zhu, Li-Min

    2007-02-20

    Covalent coupling of chitosan (CS) to activated nylon membrane was performed after the reaction of the microporous nylon membrane with formaldehyde. Non-specific adsorption on the CS-coated nylon membrane decreased greatly, compared with plain nylon membrane. The dye Cibacron Blue F3GA (CB F3GA) as a ligand was then covalently immobilized on the CS-coated membranes. Physical properties of the composite membrane and its applications in affinity membrane chromatography were examined. The contents of CS and CB F3GA-attached membranes were 89.6 mg/g nylon membrane and 146.1 micromol/g nylon membrane, respectively. These CB F3GA-attached composite membranes were used in the papain adsorption studies. Higher papain adsorption capacity, up to 235.3mg/g affinity membrane, was obtained. The adsorption isotherm fitted the Freundlich model well. Significant amount of the adsorbed papain (about 94.3%) was eluted by 1.0M NaSCN at pH 9.0. Experiments on regeneration and dynamic adsorption were also performed. It appears that CB F3GA-CS nylon membranes can be applied for papain separation without causing any denaturation.

  18. Carboxybetaine methacrylate-modified nylon surface for circulating tumor cell capture.

    PubMed

    Wang, Huiyu; Yue, Guofeng; Dong, Chaoqun; Wu, Fenglei; Wei, Jia; Yang, Yang; Zou, Zhengyun; Wang, Lifeng; Qian, Xiaoping; Zhang, Tao; Liu, Baorui

    2014-03-26

    Conventional in vitro circulating tumor cell (CTC) detection methods are always limited by blood sample volume because of the requirement of a large amount of blood. The aim of this study was to overcome the limitation by designing and making an in vivo CTC capture device. In this study, we designed and prepared a kind of proper material to serve the purpose of intervention. A method employing 3-aminopropyltriethoxysilane (γ-APS) as the coupling reagent to graft carboxybetaine methacrylate (CBMA) and to immobilize an anti-epithelial cell adhesion molecular (EpCAM) antibody on Nylon was developed. The results of X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy proved the successful graft of γ-APS and CBMA to Nylon. Furthermore, the predicted improvement in the biocompatibilities of our modified Nylon was confirmed by water contact angle measurement, bovine serum albumin adhesion, platelet adhesion, plasma recalcification time determination, and cytotoxicity tests. The tumor cells adhesion experiment revealed that Nylon with the antibody immobilized on it had an affinity for EpCAM positive tumor cells higher than that of pristine Nylon. Additionally, the capture ability of the CTCs was demonstrated in a nude mouse tumor model using the interventional device made of the modified Nylon wire. The positive results suggest that CBMA-grafted and anti-EpCAM antibody-immobilized Nylon is a promising new material for in vivo CTC capture devices.

  19. Surface chemistry of poly(p-xylylene) and nylon

    NASA Astrophysics Data System (ADS)

    Herrera-Alonso, Margarita

    The interaction of a material with its surroundings occurs at the material-environment interface, therefore, the chemical and physical characteristics of the material's surface plays a fundamental role in determining its properties, such as its biocompatibility, adhesion, and wettability, and ultimately, its technological applicability. This dissertation discusses aspects of the chemical surface modification of two polymers, poly(p-xylylene) and nylon. Chapter 2 focuses on the synthesis and wet-chemistry surface modification of poly(p-xylylene) (PPX) thin films. A series of electrophilic aromatic substitutions were studied including chlorosulfonation, chloroamidomethylation, and Friedel-Crafts catalyzed reactions. It was found that the yields and surface selectivity of the reactions studied were highly dependent on the interaction of the polymer with the reaction medium. Chapter 3 describes the use of vapor deposition polymerization in template-assisted synthesis. Poly(p-xylylene) nanotubes were synthesized by template assisted methods using porous aluminum oxide membranes as the templating material. The pore diameter showed a linear dependence with respect to the deposition time. FESEM analysis showed that PPX was deposited along the pores of the membranes. Exposure of the membranes to a reactive solution resulted in chemical functionalization of the inner walls of the nanotubes, confirmed by XPS. Chapter 4 discusses the chemical reduction of nylon film surfaces by reaction with a borane-tetrahydrofuran complex. It was observed that, while the reaction occurs in high yields, its surface-confinement is highly dependent on the segmental mobility of the polymer. The amine-rich surfaces were further used as templates for the synthesis of composite films by electrostatic adsorption of polyanions. Chapter 5 deals with the synthesis of linear polyalkyleneimines of different hydrocarbon lengths by the surface-mediated reduction of nylons. These polyalkyleneimines were

  20. Investigation of the Rigid Amorphous Fraction in Nylon-6

    SciTech Connect

    Chen,H.; Cebe, P.

    2007-01-01

    A three-phase model, comprising crystalline, mobile amorphous, and rigid amorphous fractions (X{sub c}, X{sub MA}, X{sub rA}, respectively) has been applied in the study of semicrystalline Nylon-6. The samples studied were Nylon-6 alpha phase prepared by subsequent annealing of a parent sample slowly cooled from the melt. The treated samples were annealed at 110 C, then briefly heated to 136 C, then re-annealed at 110 C. Temperature-modulated differential scanning calorimetry (TMDSC) measurements allow the devitrification of the rigid amorphous fraction to be examined. We observe a lower endotherm, termed the 'annealing' peak in the non-reversing heat flow after annealing at 110 C. By brief heating above this lower endotherm and immediately quenching in LN{sub 2}-cooled glass beads, the glass transition temperature and X{sub RA} decrease substantially, X{sub MA} increases, and the annealing peak disappears. The annealing peak corresponds to the point at which partial de-vitrification of the rigid amorphous fraction (RAF) occurs. Re-annealing at 110 C causes the glass transition and X{sub RA} to increase, and X{sub MA} to decrease. None of these treatments affected the measured degree of crystallinity, but it cannot be excluded that crystal reorganization or recrystallization may also occur at the annealing peak, contributing to the de-vitrification of the rigid amorphous fraction. Using a combined approach of thermal analysis with wide and small angle X-ray scattering, we analyze the location of the rigid amorphous and mobile amorphous fractions within the context of the Heterogeneous and Homogeneous Stack Models. Results show the homogeneous stack model is the correct one for Nylon-6. The cooperativity length ({var_epsilon}{sub A}) increases with a decrease of rigid amorphous fraction, or, increase of the mobile amorphous fraction. Devitrification of some of the RAF leads to the broadening of the glass transition region and shift of T{sub g}.

  1. Effects of BMP-12-Releasing Sutures on Achilles Tendon Healing

    PubMed Central

    Chamberlain, Connie S.; Lee, Jae-Sung; Leiferman, Ellen M.; Maassen, Nicholas X.; Baer, Geoffrey S.

    2015-01-01

    Tendon healing is a complex coordinated event orchestrated by numerous biologically active proteins. Unfortunately, tendons have limited regenerative potential and as a result, repair may be protracted months to years. Current treatment strategies do not offer localized delivery of biologically active proteins, which may result in reduced therapeutic efficacy. Surgical sutures coated with nanostructured minerals may provide a potentially universal tool to efficiently incorporate and deliver biologically active proteins directly to the wound. Additionally, previous reports indicated that treatment with bone morphogenetic protein-12 (BMP-12) improved tendon healing. Based on this information, we hypothesized that mineral-coated surgical sutures may be an effective platform for localized BMP-12 delivery to an injured tendon. The objective of this study was, therefore, to elucidate the healing effects of mineral-coated sutures releasing BMP-12 using a rat Achilles healing model. The effects of BMP-12-releasing sutures were also compared with standard BMP-12 delivery methods, including delivery of BMP-12 through collagen sponge or direct injection. Rat Achilles tendons were unilaterally transected and repaired using BMP-12-releasing suture (0, 0.15, 1.5, or 3.0 μg), collagen sponge (0 or 1.5 μg BMP-12), or direct injection (0 or 1.5 μg). By 14 days postinjury, repair with BMP-12-releasing sutures reduced the appearance of adhesions to the tendon and decreased total cell numbers. BMP-12 released from sutures and collagen sponge also tended to improve collagen organization when compared with BMP-12 delivered through injection. Based on these results, the release of a protein from sutures was able to elicit a biological response. Furthermore, BMP-12-releasing sutures modulated tendon healing, and the delivery method dictated the response of the healing tissue to BMP-12. PMID:25354567

  2. Pars plana suture fixation for intraocular lenses dislocated into the vitreous cavity using a closed-eye cow-hitch technique.

    PubMed

    Nakashizuka, Hiroyuki; Shimada, Hiroyuki; Iwasaki, Yutaka; Matsumoto, Yoko; Sato, Yukihiro

    2004-02-01

    We describe a modified intraocular cow-hitch technique for pars plana suture fixation of intraocular lenses (IOLs) that dislocated into the vitreous cavity in 3 patients who had a 3-port vitrectomy and IOL implantation because of retinal disease. To reposition the dislocated IOL after the residual vitreous was removed, 2 additional sclerotomies for suture fixation were made 3.0 mm posterior to the limbus. A loop (cow-hitch knot) was made with 10-0 polypropylene for suture fixation. After the neck of the cow-hitch loop was grasped with an intraocular forceps, the loop was used to lasso a haptic of the dislocated IOL, which was then pulled forward to the sclerotomy. The same procedure was used for the other haptic, and both sutures were secured to the sclera under scleral flaps. In all patients, the dislocated IOLs were repositioned without the need for extraction. The procedures were uneventful. Pars plana suture fixation with the intraocular cow-hitch technique can be used to reposition an IOL that has dislocated into the vitreous cavity.

  3. The Paleotethys suture in Central Iran

    NASA Astrophysics Data System (ADS)

    Bagheri, S.; Stampfli, G. M.

    2003-04-01

    The Triassic rocks of the Nakhlak area have been used to justify the hypothesis of the rotation of the Central-East Iranian microplate, mainly based on paleomagnetic data. Davoudzadeh and his coworkers (1981) pointed out the existing contrast between the Nakhlakh succession and the time-equivalent lithostratigraphic units exposed in the surrounding regions and compared them with the Triassic rocks of the Aghdarband area on the southern edge of the Turan plate. We recently gathered evidences that this part of central Iran effectively belongs to the Northern Iranian Paleo-Tethys suture zone and related Variscan terrains of the Turan plate. This is the case for the northwestern part of central Iran, where the Anarak-Khur belt (Anarak schists and their thick Cretaceous-Paleocene sedimentary cover) presents all the elements of an orogenic zone such as dismembered ophiolites and silisiclastics, calcareous and volcanic cover which has been deformed and metamorphosed. This belt is separated to the northwest from the Alborz microcontinent by the Great Kavir fault and Cretaceous ophiolite mélanges. To the southeast it is bounded by the Biabanak fault and serpentinites and the Biabanak block, part of the central-east Iranian plate. The later zone is formed by Proterozoic metamorphic basement and marine sedimentary cover, nearly continuous from the Ordovician to the Triassic, at the uppermost part upper Triassic-lower Jurassic bauxites and silisiclastics are observed. Excepted the Ordovician angular unconformities and the boundary between lower Jurassic and younger layers, this sequence displays no significant main unconformities and can be attributed to the Cimmerian super-terrain. Thus, this sequences represents the classical evolution of the southern Paleo-Tethys passive margin, as found in the Alborz microcontinent or the Band-e Bayan zone of Afghanistan and is the witness of large scale duplication of the Paleo-Tethys suture zone through major Alpine strike-slip faults

  4. Surface modifications of nylon/carbon fiber composite for improving joint adhesion

    SciTech Connect

    Wu, R.; Liao, S.L.; Tong, T.S.; Young, J.T.

    1996-12-31

    Various methods were used to modify the nylon/carbon fiber composite surfaces, including grit blasting, flame and plasma pretreatments. The surfaces of nylon composites after pretreatments were characterized by contact angle measurements, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). XPS results show that several functional groups were formed after plasma and flame pretreatments. The scanning electron microscope (SEM) photographs suggest that the blasting pretreatment increased the surface roughness of nylon composites. All these surface pretreatments dramatically increased the lap shear strength if proper operation conditions were used. The reasons for the increase of lap shear strength were explained.

  5. Large Extremity Peripheral Nerve Repair

    DTIC Science & Technology

    2013-10-01

    harvested from donor rats immediately post-euthanasia (Task 1g) and bonding of the wrap around the nerve ends performed following application of 0.1...a) epineurial suture, (b) fibrin glue and (c) photochemical tissue bonding (PTB) with a wrap material. All methods induced bonding between the nerve...segments with bond strength in the order of suture>PTB> fibrin glue. Conventional epineurial suturing using six 10.0 nylon sutures resulted in the

  6. The Utilization of Long Nylon Catheters for Prolonged Intravenous Infusions

    PubMed Central

    Roy, Ronald B.; Wilkinson, R. H.; Bayliss, C. E.

    1967-01-01

    A study of 300 patients receiving intravenous therapy showed that 90 had associated phlebitis. Because of this high rate of complications, the use of long plastic catheters, with the tip located in a large central vessel, was investigated. One hundred and one catheters were inserted into the basilic vein through a cut-down. The patients were divided into four groups: infusions lasting one to seven days, eight to 14 days, 15 to 28 days and 29 days or longer. The most common complication was obstruction of the catheter with clotted blood. In four patients the catheters had to be removed because of phlebitis; two were pulled out by the patients themselves. Infection was not observed. Two factors probably contributed to the successful infusions: the composition of the plastic catheters (nylon) and the location of the tip in a large central vessel. ImagesFig. 1Fig. 2Fig. 3 PMID:6017172

  7. Nylon production: An unknown source of atmospheric nitrous oxide

    SciTech Connect

    Thiemens, M.H.; Trogler, W.C. )

    1991-02-22

    Nitrous oxide in the earth's atmosphere contributes to catalytic stratospheric ozone destruction and is also a greenhouse gas component. A precise budgetary accounting of N{sub 2}O sources has remained elusive, and there is an apparent lack of source identification. One source of N{sub 2}O is as a by-product in the manufacture of nylon, specifically in the preparation of adipic acid. Characterization of the reaction N{sub 2}O stoichiometry and its isotopic composition with a simulated industrial adipic acid synthesis indicates that because of high rates of global adipic acid production, this N{sub 2}O may account for {approximately}10% of the increase observed for atmospheric N{sub 2}O.

  8. A Novel Porous Nylon Biocarrier for Immobilized Bacteria

    PubMed Central

    Heitkamp, M. A.; Stewart, W. P.

    1996-01-01

    A highly porous nylon biocarrier was developed to support immobilized bacteria in bioreactors used to treat liquid wastes. Porosity analyses and scanning electron microscopy showed microbial colonization of accessible pores typically in the range of 100 to 1,200 (mu)m, with some as large as 3.9 mm. A bench-scale packed-bed reactor achieved a p-nitrophenol (PNP) removal rate of 5.95 kg of PNP m(sup-3) day(sup-1) for wastes containing 1,200 mg of PNP liter(sup-1). Complete mixing of the biocarrier bed to remove excess surface biomass was routinely achieved with simple air injection. These porous polymer biocarriers are promising as microbial supports in liquid-waste treatment and bioremediation applications. PMID:16535474

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

    PubMed

    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.

  10. Suture-Only Repair Versus Suture Anchor–Augmented Repair for Achilles Tendon Ruptures With a Short Distal Stump

    PubMed Central

    Boin, Michael A.; Dorweiler, Matthew A.; McMellen, Christopher J.; Gould, Gregory C.; Laughlin, Richard T.

    2017-01-01

    Background: Chronic noninsertional Achilles tendinosis can result in an acute Achilles tendon rupture with a short distal stump. In such tendon ruptures, there is a limited amount of adequate tissue that can hold suture, thus presenting a challenge for surgeons who elect to treat the rupture operatively. Hypothesis: Adding suture anchors to the repair construct may result in biomechanically stronger repairs compared with a suture-only technique. Study Design: Controlled laboratory study. Methods: Nine paired Achilles-calcaneus complexes were harvested from cadavers. An artificial Achilles rupture was created 2 cm proximal to the insertion on the calcaneus. One specimen from each cadaver was assigned to a suture-only or a suture anchor–augmented repair. The contralateral specimen of the same cadaver received the opposing repair. Cyclic testing was then performed at 10 to 100 N for 2000 cycles, and load-to-failure testing was performed at 0.2 mm/s. This was followed by analysis of repair displacement, gapping at repair site, peak load to failure, and failure mode. Results: The suture anchor–augmented repair exhibited a 116% lower displacement compared with the suture-only repair (mean ± SD, 1.54 ± 1.13 vs 3.33 ± 1.47 mm, respectively; P < .03). The suture anchor–augmented repair also exhibited a 45% greater load to failure compared with the suture-only repair (303.50 ± 102.81 vs 209.09 ± 48.12 N, respectively; P < .04). Conclusion: Suture anchor–augmented repairs performed on acute Achilles tendon ruptures with a short distal stump are biomechanically stronger than suture-only repairs. Clinical Relevance: Our results support the use of suture anchor–augmented repairs for a biomechanically stronger construct in Achilles tendon ruptures with a short distal stump. Biomechanically stronger repairs may lead to less tendon repair gapping and failure, increasing the ability to start early active rehabilitation protocols and thus improving patient outcomes

  11. Modeling of Needle-Tissue Interaction Forces During Surgical Suturing

    PubMed Central

    Jackson, Russell C.; Çavuşoğlu, M. Cenk

    2013-01-01

    This paper presents a model of needle tissue interaction forces that a rigid suture needle experiences during surgical suturing. The needle-tissue interaction forces are modeled as the sum of lumped parameters. The model has three main components; friction, tissue compression, and cutting forces. The tissue compression force uses the area that the needle sweeps out during a suture to estimate both the force magnitude and force direction. The area that the needle sweeps out is a direct result of driving the needle in a way that does not follow the natural curve of the needle. The friction force is approximated as a static friction force along the shaft of the needle. The cutting force acts only on the needle tip. The resulting force and torque model is experimentally validated using a tissue phantom. These results indicate that the proposed lumped parameter model is capable of accurately modeling the forces experienced during a suture. PMID:24683499

  12. Use of absorbable sutures in canine carotid arteries.

    PubMed

    Rey, A R; Carrillo-Farga, J; Velasco, C O; Valencia, M O

    1990-01-01

    To study the functional and microstructural characteristics of polydioxanone sutures in vascular surgery, we created 48 vascular anastomoses in the right and left common carotid arteries of 24 mongrel dogs. In each animal, polydioxanone sutures were used in 1 carotid artery, and polypropylene sutures were used in the contralateral carotid artery. Twelve groups of 2 animals each were then formed. The 1st group was observed for 1 month, the 2nd for 2 months, the 3rd for 3 months, and so on until the 12th group, which was observed for 12 months. At the end of each observation period, reoperation was undertaken to evaluate the vascular anastomoses by means of angiography and microscopy. The polypropylene anastomoses showed a marked deformity, with tissue retraction and a foreign body reaction. In contrast, the polydioxanone anastomoses exhibited satisfactory healing, without deformity, and were well tolerated histologically. We believe that polydioxanone may be a useful, alternative vascular suture material.

  13. [Pilot study on facial palsy correction with suture suspension].

    PubMed

    Navarrete Álvaro, María Luisa; Knäpper, Jennifer; Boemo, Rafael; Torrent, Lluisa

    2011-01-01

    We present a pilot study to evaluate the benefit of static facial suspension with Silhouette sutures. We operated on a female patient with complete facial palsy secondary to otic tuberculosis. The patient has currently achieved satisfactory facial symmetry, mastication and speech production. As a result, self-esteem and social interaction have also been recovered. Static facial suspension with Silhouette sutures is an alternative to dynamic techniques in patients who do not wish to or cannot undergo those more complex surgeries.

  14. Bacterial Adherence to High Tensile-Strength Sutures.

    DTIC Science & Technology

    2011-06-01

    system. In addition, suture an- chors are typically preloaded with No. 2 sutures. Bioluminescent Bacteria The bacterial broth prepared for this... bacteria strain are genetically engineered to emit photons, allowing for quantification with a photon-counting camera sys- tem. Bioluminescent bacteria ... bioluminescent in vitro model. Methods: Eleven strands each of No. 2 MaxBraid (Arthrotek [Biomet], Warsaw, IN), FiberWire (Arthrex, Naples, FL), Ethibond

  15. Nasal packing and transseptal suturing techniques: surgical and anaesthetic perspectives.

    PubMed

    Günaydın, Rıza Önder; Aygenc, Erdinc; Karakullukcu, Selma; Fidan, Fatih; Celikkanat, Serdar

    2011-08-01

    The objective of this study is to compare the nasal packing and the transseptal suturing techniques regarding the extubation difficulty evaluation scores, follow-up times in post-anaesthesia care unit (PACU), pain scores, and postoperative complications. Two hundred patients who underwent septoplasty from January 2009 to October 2009 were randomly assigned either to have nasal packs (n: 100) or transeptal sutures (n: 100). In the transseptal suture group, extubation was easier and PACU follow-up times were shorter, when compared to the nasal packing group (p < 0.001). Patients with nasal packing had significantly higher pain scores (p < 0.001). Minor bleeding was significantly higher in the transseptal group with seven cases, compared to the nasal packing group without any bleeding cases (p = 0.014). There were two patients who had postoperative major bleeding, and two patients who had septal hematoma in the transseptal suture group. One patient with nasal packing had postoperative infection. Septal perforation was not seen in any of the cases. While patients in both groups experienced postoperative crusting, patients in the transseptal suture group also complained about foreign body sensation. Extubation was more comfortable; post-anaesthesia monitorization duration was shorter, and postoperative pain was less, but minor bleeding was seen more with transseptal sutures. There was no significant difference in terms of major bleeding, hematoma, infection or perforation. Foreign body sensation was the main cause of postoperative discomfort in the transseptal suture group. Transseptal suturing might be a significantly comfortable, cost-effective and reliable alternative to nasal packing.

  16. Measurement of the radon diffusion through a nylon foil for different air humidities

    SciTech Connect

    Mamedov, Fadahat; Štekl, Ivan; Smolek, Karel

    2015-08-17

    The dependency of the radon penetration through a nylon foil on air humidity was measured. Such information is needed for the tracking part of the SuperNEMO detector, which is planned to be shielded against radon by nylon foil and in which the air humidity is not negligible. The long term measurements of radon penetration through nylon foils for different air humidities were performed with the radon diffusion setup constructed at the IEAP, CTU in Prague. The setup consists of two stainless steel hemispheres with Si detector in each of them. Both hemispheres are separated by the tested foil. While the left hemisphere contains high Rn activity, the right part contains only activity caused by the radon penetration through the tested foil. Obtained results of this study with a nylon foil with the thickness of 50 µm are presented.

  17. Synthesis and characterization of diamond-coated CNTs and their reinforcement in Nylon-6 single fiber.

    PubMed

    Rangari, Vijaya K; Mohammad, Ghouse M; Jeelani, Shaik; Butenko, Yuri V; Dhanak, Vinod R

    2010-07-01

    Diamond nanoparticle (DN)-coated CNTs were synthesized using a cationic surfactant-assisted sonochemical method. The as-prepared DN coated CNTs were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The results show that the DNs were coated on the outer wall surface of CNTs. The DN-coated CNTs were infused in Nylon-6 polymer through a melt extrusion process to form nanocomposite fibers that were tested for their tensile properties. The ultimate tensile strength is found to be 363 MPa for DN/CNTs/Nylon-6 single fibers as compared to 240 MPa for neat Nylon-6 single fibers. These results were also compared with Nylon-6 fibers infused with pristine CNTs and pristine DNs.

  18. Measurement of the radon diffusion through a nylon foil for different air humidities

    NASA Astrophysics Data System (ADS)

    Mamedov, Fadahat; Štekl, Ivan; Smolek, Karel

    2015-08-01

    The dependency of the radon penetration through a nylon foil on air humidity was measured. Such information is needed for the tracking part of the SuperNEMO detector, which is planned to be shielded against radon by nylon foil and in which the air humidity is not negligible. The long term measurements of radon penetration through nylon foils for different air humidities were performed with the radon diffusion setup constructed at the IEAP, CTU in Prague. The setup consists of two stainless steel hemispheres with Si detector in each of them. Both hemispheres are separated by the tested foil. While the left hemisphere contains high Rn activity, the right part contains only activity caused by the radon penetration through the tested foil. Obtained results of this study with a nylon foil with the thickness of 50 µm are presented.

  19. Rubbing skin with nylon towels as a major cause of pseudomonas folliculitis in a Japanese population.

    PubMed

    Teraki, Yuichi; Nakamura, Kaori

    2015-01-01

    Pseudomonas folliculitis (PF) is a community-acquired skin infection, which develops after exposure to contaminated water such as whirlpools, swimming pools, water slides and hot tubs. In Japan, this condition has been sporadically reported, often in association with bathing; however, the exact cause of PF in the Japanese population remains unclear. In this study, we retrospectively reviewed 10 patients with PF diagnosed at our dermatology clinic (two males and eight females). Four patients had recurrences over 1-3 years. Notably, eight of the 10 patients were rubbing their bodies with nylon towels or sponges placed in the bathrooms during bathing. Pseudomonas aeruginosa was isolated from the nylon towels used in two of the two patients examined. Discontinued use of nylon towels resulted in prompt resolution of PF and no recurrence in all cases. Our observation suggests that rubbing the skin with nylon towels contaminated with P. aeruginosa was a major cause of PF in a Japanese population.

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

    PubMed

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

    2015-11-01

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

  1. Dietary consistency and the midline sutures in growing pigs

    PubMed Central

    Burn, AK; Herring, SW; Hubbard, R; Zink, K; Rafferty, K; Lieberman, DE

    2010-01-01

    Objectives The purpose of this study was to investigate the effects of reduced masticatory function on midline suture growth and morphology in growing pigs. Setting and Sample Population The sample was 20 pigs separated into 2 dietary groups, and raised at the Department of Antrhopology, Harvard University. Midline suture specimes were analyzed at the Department of Orthodontics, University of Washington. Materials and Methods Ten farm pigs and 10 minipigs, all male, were randomly assigned to hard (n=9) and soft diet (n=11) groups. Fluorochromic mineral labels were administered to document bone apposition, and the animals were sacrificed after 12 weeks. Undecalcified sections of the interfrontal, interparietal, internasal and intermaxillary sutures were evaluated for bone quantity and sutural thickness, interdigitation ratio and growth rate. Results Soft diet pigs were characterized by a slower rate of weight gain, and less bone than their hard diet counterparts. Even after correction for weight gain, soft diet pigs had reduced suture growth rate and thickness. However, no difference in interdigitation ratio was detected between dietary groups. Conclusion Restriction to a soft diet reduces midline suture growth and bone apposition in the growing pig. PMID:20477970

  2. Silver-Coated Nylon Dressing Plus Active DC Microcurrent for Healing of Autogenous Skin Donor Sites

    DTIC Science & Technology

    2013-08-01

    Silver-Coated Nylon Dressing Plus Active DC Microcurrent for Healing of Autogenous Skin Donor Sites Edward W. Malin, MD, Chaya M. Galin, BSN, RN... microcurrent in comparison to silver-coated dressing with sham microcurrent on wound-closure time for autogenous skin donor sites. Methods: Four...hundred five patients were screened for treatment of their donor sites using a silver-coated nylon dressing with either sham or active microcurrent

  3. Nylon-3 Co-Polymers that Generate Cell-Adhesive Surfaces Identified by Library Screening

    PubMed Central

    Lee, Myung-Ryul; Stahl, Shannon S.; Gellman, Samuel H.; Masters, Kristyn S.

    2010-01-01

    Polymers in the nylon-3 family contain subunits derived from β-amino acids, which are linked to one another via amide bonds. Thus, the nylon-3 backbone is homologous to the α-amino acid-based backbone of proteins. This molecular-level homology suggests that nylon-3 materials might be intrinsically protein-mimetic. The experiments described here explore this prospect in the context of cell adhesion, with tissue engineering as a long-range goal. We have evaluated a small library of sequence-random nylon-3 copolymers for the ability to render surfaces attractive to NIH 3T3 fibroblast adhesion and spreading. Library screening was accomplished in a high-throughput, parallel mode via attachment of the copolymers in a two-dimensional array to a modified glass surface. Significant variations in fibroblast adhesion and spreading were observed as a function of nylon-3 subunit identity and proportion. Several of the nylon-3 copolymers supported cell adhesion and morphology that was comparable, or even superior, to that achieved on positive control substrates such as tissue culture polystyrene and collagen-coated glass. Moreover, studies conducted under serum-free conditions demonstrated that specific nylon-3 derivatives supported cell adhesion independently of serum protein adsorption. Although cell adhesion was diminished in the absence of serum, particular copolymers demonstrated an ability to support substantially greater cell adhesion than any of the other conditions, including the positive controls. The nylon-3 copolymers that were most effective at promoting adhesion to a modified glass surface proved also to be effective at promoting adhesion when attached to a PEG-based hydrogel, demonstrating the potential for these copolymers to be used in tissue engineering applications. PMID:19886604

  4. Nylon-3 copolymers that generate cell-adhesive surfaces identified by library screening.

    PubMed

    Lee, Myung-Ryul; Stahl, Shannon S; Gellman, Samuel H; Masters, Kristyn S

    2009-11-25

    Polymers in the nylon-3 family contain subunits derived from beta-amino acids, which are linked to one another via amide bonds. Thus, the nylon-3 backbone is homologous to the alpha-amino acid-based backbone of proteins. This molecular-level homology suggests that nylon-3 materials might be intrinsically protein-mimetic. The experiments described here explore this prospect in the context of cell adhesion, with tissue engineering as a long-range goal. We have evaluated a small library of sequence-random nylon-3 copolymers for the ability to render surfaces attractive to NIH 3T3 fibroblast adhesion and spreading. Library screening was accomplished in a high-throughput, parallel mode via attachment of the copolymers in a two-dimensional array to a modified glass surface. Significant variations in fibroblast adhesion and spreading were observed as a function of nylon-3 subunit identity and proportion. Several of the nylon-3 copolymers supported cell adhesion and morphology that was comparable, or even superior, to that achieved on positive control substrates such as tissue culture polystyrene and collagen-coated glass. Moreover, studies conducted under serum-free conditions demonstrated that specific nylon-3 derivatives supported cell adhesion independently of serum protein adsorption. Although cell adhesion was diminished in the absence of serum, particular copolymers demonstrated an ability to support substantially greater cell adhesion than any of the other conditions, including the positive controls. The nylon-3 copolymers that were most effective at promoting adhesion to a modified glass surface proved also to be effective at promoting adhesion when attached to a PEG-based hydrogel, demonstrating the potential for these copolymers to be used in tissue engineering applications.

  5. [The invention and application of the vaginal suturing-aid apparatus].

    PubMed

    Cheng, Yu-ping

    2002-07-01

    We have invented a barrel-shape suturing-aid apparatus with a light source on one side and a trapzoid cranny for suturing on the other side. There are many advantages proved by clinical practices in applying the suturing-aid apparatus: 1. to increase the suturing speed and relieve the pains of patients; 2. to avoid the infection of HBV by blood and crossinfection; 3. to improve the illumination condition and avoid no suturing of the hurt tissue.

  6. Nylon-Graphene Composite Nonwovens as Monolithic Conductive or Capacitive Fabrics.

    PubMed

    Pan, Qin; Shim, Eunkyoung; Pourdeyhimi, Behnam; Gao, Wei

    2017-03-08

    Here we describe a nylon-graphene nonwoven (NGN) composite, prepared via melt-blowing of nylon-6 into nonwoven fabrics and infiltrate those with graphene oxide (GO) in aqueous dispersions, which were further chemically reduced into graphene to offer electrical conductivity. The correlation between the conductivity and the graphene loading is described by the percolation scaling law σ = (p - pc)(t), with an exponent t of 1.2 and a critical concentration pc of 0.005 wt %, the lowest among all the nylon composites reported. Monolithic supercapacitors have been further developed on the nylon-GO nonwoven composites (NGO), via a programed CO2-laser patterning process. The nylon nonwoven works as an efficient matrix, providing high capacity to GO and ensuring enough electrode materials generated via the subsequent laser patterning processes. Our best monolithic supercapacitors exhibited an areal capacitance of 10.37 mF cm(-2) in PVA-H2SO4 electrolyte, much higher than the 1-3 mF cm(-2) reported for typical microsupercapacitors. Moreover, our supercapacitors were able to retain a capacitance density of 5.07 mF cm(-2) at an ultrahigh scan rate (1 V s(-1)), probably due to the facilitated ion migration within the highly porous nonwoven framework. This is the first report of highly functional nylon-6 nonwovens, fabricated via industrially scalable pathways into low-cost conductive polymer matrices and disposable energy storage systems.

  7. Polyvinyl alcohol {gamma}-ray grafted nylon 4 membrane for pervaporation and evapomeation

    SciTech Connect

    Lai, J.Y.; Chen, R.Y.; Lee, K.R

    1993-05-01

    Nylon 4, which possesses high mechanical strength and good affinity for water, can be considered as a liquid separation membrane. To improve the hydrophilicity of a Nylon 4 membrane for pervaporation and evapomeation processes, and to overcome the hydrolysis of polyvinyl alcohol (PVA), this study attempts to prepare a PVA-g-Nylon 4 membrane by {gamma}-ray irradiation grafting of vinyl acetate (VAc) onto Nylon 4 membrane, followed by hydrolysis treatment. The effects of down-stream pressure, irradiation dose, VAc monomer concentration, degree of grafting, feed composition, and size of alcohols on the separation of water-alcohol mixtures were studied. The surface properties of the prepared membrane were characterized by FTIR, ESCA, and a contact angle meter. A separation factor of 13.8 and a permeation rate of 0.352 kg/m{sup 2}-h can be obtained for a PVA-g-Nylon 4 membrane with a degree of grafting of 21.2% for a 90-wt% ethanol feed concentration. Compared to the pervaporation process, the evapomeation process has a significantly increased separation factor with a decreased permeation rate for the same PVA-g-Nylon 4 membrane. 24 refs., 9 figs., 4 tabs.

  8. Alignment of carbon nanotubes and reinforcing effects in nylon-6 polymer composite fibers

    NASA Astrophysics Data System (ADS)

    Rangari, Vijaya K.; Yousuf, Mohammed; Jeelani, Shaik; Pulikkathara, Merlyn X.; Khabashesku, Valery N.

    2008-06-01

    Alignment of pristine carbon nanotubes (P-CNTs) and fluorinated carbon nanotubes (F-CNTs) in nylon-6 polymer composite fibers (PCFs) has been achieved using a single-screw extrusion method. CNTs have been used as filler reinforcements to enhance the mechanical and thermal properties of nylon-6 composite fibers. The composites were fabricated by dry mixing nylon-6 polymer powder with the CNTs as the first step, then followed by the melt extrusion process of fiber materials in a single-screw extruder. The extruded fibers were stretched to their maxima and stabilized using a godet set-up. Finally, fibers were wound on a Wayne filament winder machine and tested for their tensile and thermal properties. The tests have shown a remarkable change in mechanical and thermal properties of nylon-6 polymer fibers with the addition of 0.5 wt% F-CNTs and 1.0 wt% of P-CNTs. To draw a comparison between the improvements achieved, the same process has been repeated with neat nylon-6 polymer. As a result, tensile strength has been increased by 230% for PCFs made with 0.5% F-CNTs and 1% P-CNTs as additives. These fibers have been further characterized by DSC, Raman spectroscopy and SEM which confirm the alignment of CNTs and interfacial bonding to nylon-6 polymer matrix.

  9. Alignment of carbon nanotubes and reinforcing effects in nylon-6 polymer composite fibers.

    PubMed

    Rangari, Vijaya K; Yousuf, Mohammed; Jeelani, Shaik; Pulikkathara, Merlyn X; Khabashesku, Valery N

    2008-06-18

    Alignment of pristine carbon nanotubes (P-CNTs) and fluorinated carbon nanotubes (F-CNTs) in nylon-6 polymer composite fibers (PCFs) has been achieved using a single-screw extrusion method. CNTs have been used as filler reinforcements to enhance the mechanical and thermal properties of nylon-6 composite fibers. The composites were fabricated by dry mixing nylon-6 polymer powder with the CNTs as the first step, then followed by the melt extrusion process of fiber materials in a single-screw extruder. The extruded fibers were stretched to their maxima and stabilized using a godet set-up. Finally, fibers were wound on a Wayne filament winder machine and tested for their tensile and thermal properties. The tests have shown a remarkable change in mechanical and thermal properties of nylon-6 polymer fibers with the addition of 0.5 wt% F-CNTs and 1.0 wt% of P-CNTs. To draw a comparison between the improvements achieved, the same process has been repeated with neat nylon-6 polymer. As a result, tensile strength has been increased by 230% for PCFs made with 0.5% F-CNTs and 1% P-CNTs as additives. These fibers have been further characterized by DSC, Raman spectroscopy and SEM which confirm the alignment of CNTs and interfacial bonding to nylon-6 polymer matrix.

  10. Functionalization of nylon membranes via surface-initiated atom-transfer radical polymerization.

    PubMed

    Xu, F J; Zhao, J P; Kang, E T; Neoh, K G; Li, J

    2007-07-31

    The ability to manipulate and control the surface properties of nylons is of crucial importance to their widespread applications. In this work, surface-initiated atom-transfer radical polymerization (ATRP) is employed to tailor the functionality of the nylon membrane and pore surfaces in a well-controlled manner. A simple two-step method, involving the activation of surface amide groups with formaldehyde and the reaction of the resulting N-methylol polyamide with 2-bromoisobutyryl bromide, was first developed for the covalent immobilization of ATRP initiators on the nylon membrane and its pore surfaces. Functional polymer brushes of 2-hydroxyethyl methacrylate (HEMA) and poly(ethylene glycol)monomethacrylate (PEGMA) were prepared via surface-initiated ATRP from the nylon membranes. A kinetics study revealed that the chain growth from the membranes was consistent with a "controlled" process. The dormant chain ends of the grafted HEMA polymer (P(HEMA)) and PEGMA polymer (P(PEGMA)) on the nylon membranes could be reactivated for the consecutive surface-initiated ATRP to produce the corresponding nylon membranes functionalized by P(HEMA)-b-P(PEGMA) and P(PEGMA)-b-P(HEMA) diblock copolymer brushes. In addition, membranes with grafted P(HEMA) and P(PEGMA) brushes exhibited good resistance to protein adsorption and fouling under continuous-flow conditions.

  11. [Research on structure of MC-nylon 6/aramid composites by spectroanalysis method].

    PubMed

    Wang, Can-Yao; Zheng, Yu-Ying

    2008-01-01

    The Kevlar fiber, treated with toluene-2,4-diisocyanate and caprolactam, was used to reinforce MC nylon 6. XPS showed the change in chemical components and spectra after fiber was treated. IR showed that the spectra of Kevlar fiber and MC-nylon 6 were incorporated purely when they were mixed, while the treated Kevlar fiber provided the activation in the ring-opening polymerization of caprolactam, and the amide groups of graft chains could form strong hydrogen bonds with matrix. These graft chains and hydrogen bonds would contribute to improving interfacial bonding between MC-nylon 6 and Kevlar fiber. XRD indicated that the induction of Kevlar fiber had no effect on the cryastalline style of MC-nylon 6 obviously, however, the crystals had better seasonal structure. The crystals of MC-nylon 6/Kevlar fiber composites were more perfect than that of MC-nylon 6/Kevlar untreated fiber composites with the same amount of Kevlar fiber. The increase of Kevlar fiber contributed to forming perfect a spherulite when the mass concentration of Kevlar fiber was less than 2%, however, the more the Kevlar fiber, the less the content of a spherulite when the mass concentration of Kevlar fiber was more than 2%.

  12. Nylon 6,6 Nonwoven Fabric Separates Oil Contaminates from Oil-in-Water Emulsions

    PubMed Central

    Carter, Erin S.; Ortega, Albert E.

    2016-01-01

    Industrial oil spills into aquatic environments can have catastrophic environmental effects. First responders to oil spills along the coast of the Gulf of Mexico in the southern United States have used spunbond nylon fabric bags and fences to separate spilled oil and oil waste from contaminated water. Low area mass density spunbond nylon is capable of sorbing more than 16 times its mass in low viscosity crude oil and more than 26 times its mass in higher viscosity gear lube oil. Nylon bags separated more than 95% of gear lube oil contaminate from a 4.5% oil-in-water emulsion. Field testing of spunbond nylon fences by oil spill first responders has demonstrated the ability of this material to contain the oily contaminate while allowing water to flow through. We hypothesize that the effectiveness of nylon as an oil filter is due to the fact that it is both more oleophilic and more hydrophilic than other commonly used oil separation materials. The nylon traps oil droplets within the fabric or on the surface, while water droplets are free to flow through the fabric to the water on the opposite side of the fabric. PMID:27411088

  13. Diminished suture strength after robotic needle driver manipulation.

    PubMed

    Ricchiuti, Daniel; Cerone, Jeffrey; Shie, Scott; Jetley, Ajay; Noe, Donald; Kovacik, Mark

    2010-09-01

    Robot-assisted minimally invasive surgery has become a routine surgical option for the treatment of prostate cancer. Despite its technical advancements, the da Vinci(®) Surgical System still lacks haptic feedback to the surgeon, resulting in a maximally applied compressive force by the robotic needle driver during every grasping maneuver. Without this perceptional sense of touch and grip control, repetitive robotic needle driver manipulation may unknowingly lead to irreparable damage to fine sutures used during delicate anastomotic repairs. For robotic prostatectomy, any such loss of integrity can potentially lead to premature breakdown of the urethrovesical anastomosis and urine extravasation, especially important for a less-than-perfectly fashioned anastomotic repair. Although it has already been established that overhandling of sutures using handheld laparoscopic instruments can lead to reduced suture strength, it has not been established to what extent this may occur after robotic surgical procedures. We present analytical data and analyses concerning the failure strength of fine sutures commonly used for urethrovesical anastomotic repair during robotic prostatectomy, after repetitive robotic needle driver manipulation. When compared with noncompromised monofilament suture controls, the average maximal failure force after repetitive robotic manipulation was significantly reduced by 35% (p < 0.0001). Similarly, the average maximal failure force of braided sutures was significantly reduced after repetitive robotic manipulation by 3% (p = 0.009). This work demonstrates that significant reductions in monofilament and braided suture strength integrity can occur after customary repetitive manipulation by robotic needle drivers in an ex vivo model, with further research warranted in the in vivo setting.

  14. Highly Stretchable Non-volatile Nylon Thread Memory

    PubMed Central

    Kang, Ting-Kuo

    2016-01-01

    Integration of electronic elements into textiles, to afford e-textiles, can provide an ideal platform for the development of lightweight, thin, flexible, and stretchable e-textiles. This approach will enable us to meet the demands of the rapidly growing market of wearable-electronics on arbitrary non-conventional substrates. However the actual integration of the e-textiles that undergo mechanical deformations during both assembly and daily wear or satisfy the requirements of the low-end applications, remains a challenge. Resistive memory elements can also be fabricated onto a nylon thread (NT) for e-textile applications. In this study, a simple dip-and-dry process using graphene-PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) ink is proposed for the fabrication of a highly stretchable non-volatile NT memory. The NT memory appears to have typical write-once-read-many-times characteristics. The results show that an ON/OFF ratio of approximately 103 is maintained for a retention time of 106 s. Furthermore, a highly stretchable strain and a long-term digital-storage capability of the ON-OFF-ON states are demonstrated in the NT memory. The actual integration of the knitted NT memories into textiles will enable new design possibilities for low-cost and large-area e-textile memory applications. PMID:27072786

  15. Highly Stretchable Non-volatile Nylon Thread Memory

    NASA Astrophysics Data System (ADS)

    Kang, Ting-Kuo

    2016-04-01

    Integration of electronic elements into textiles, to afford e-textiles, can provide an ideal platform for the development of lightweight, thin, flexible, and stretchable e-textiles. This approach will enable us to meet the demands of the rapidly growing market of wearable-electronics on arbitrary non-conventional substrates. However the actual integration of the e-textiles that undergo mechanical deformations during both assembly and daily wear or satisfy the requirements of the low-end applications, remains a challenge. Resistive memory elements can also be fabricated onto a nylon thread (NT) for e-textile applications. In this study, a simple dip-and-dry process using graphene-PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) ink is proposed for the fabrication of a highly stretchable non-volatile NT memory. The NT memory appears to have typical write-once-read-many-times characteristics. The results show that an ON/OFF ratio of approximately 103 is maintained for a retention time of 106 s. Furthermore, a highly stretchable strain and a long-term digital-storage capability of the ON-OFF-ON states are demonstrated in the NT memory. The actual integration of the knitted NT memories into textiles will enable new design possibilities for low-cost and large-area e-textile memory applications.

  16. Large Vertical Axis Rotations along Neotethyan Sutures in TURKEY

    NASA Astrophysics Data System (ADS)

    Ozkaptan, M.; Gulyuz, E.; Kaymakci, N.; Langereis, C. G.; Ozacar, A. A.; Lefebvre, C.

    2014-12-01

    Two Neotethyan Sutures,Izmir-Ankara and Intra-Tauride suture zones meet around Ankara region appx. at right angles.The northerly located Izmir-Ankara Suture zone follows approximately E-W trend and it makes a sharp approximately 90° bend at the east along the western margin of the Çankiri Basin.The Intra-Tauride suture follows approximately the Tuzgölü Fault Zone and trends NW-SE and seems to be overprinted by the structures related to the Izmir-Ankara suture zone. These two sutures meet southeastern corner of the Haymana Basin where the basin makes major eastwards counterclockwise bend.From west to East, the Haymana, Tuzgölü and Çankiri Basins straddle these suture zones and are developed in relation to the subduction and collision processes in the region, making them the perfect sites to unravel deformation history and paleogeography of the Neotethyan suture zones in the region. In order to accomplish this, the tectono-stratigraphic evolution of the basin and its paleogeographical positions, in different time slices, constructed by conducting a very detailed study on the Late Cretaceous to Recent infill of the Haymana, Tuzgölü, and Çankiri Basins. We collected more than 4500 sedimentary paleomagnetic samples for paleomagnetic purposes from 112 different locations within 250 km diameter area.Before the demagnetization process, nearly 3000 core specimens were measured for anisotropy of magnetic susceptibility (AMS) in order to understand deformation amounts and kinematics.The paleomagnetic results show that the region underwent strong clockwise and counterclockwise rotations more than 90° in places, resulting in the present geometry of the suture zones. The central part of the Haymana basin rotated as high as 90° counterclockwise while its northern part together with the southwestern part of the Çankiri basin and northern part of the Tuzgölü basin rotated approximately 30° clockwise contrary to almost all published paleomagnetic data from the region

  17. Study on the effects of nylon-chitosan-blended membranes on the spheroid-forming activity of human melanocytes.

    PubMed

    Lin, Sung-Jan; Hsiao, Wen-Chu; Jee, Shiou-Hwa; Yu, Hsin-Su; Tsai, Tsen-Fang; Lai, Juin-Yih; Young, Tai-Horng

    2006-10-01

    Though reported limitedly in tissue engineering, modification of cellular functions can be achieved by culturing them into multicellular spheroids. We have shown melanocytes form spheroids on chitosan surface. However, how biomaterials promote spheroid formation has never been systemically investigated. In this work, nylon, which inhibits melanocyte spheroid formation, and chitosan, which promotes melanocyte spheroid formation, are used to prepare nylon/chitosan-blended membranes. Membranes composed of pure nylon, pure chitosan and various ratios of nylon and chitosan are employed to examine their effects on spheroid formation. Melanocytes show better adhesion to nylon membranes than that to chitosan membranes. In blended membranes, as more nylon is incorporated, cell adhesion increases and the trend for spheroid formation decreases. Melanocytes can only form spheroids on membranes with poorer cell adhesion. Examining the surface of the blended membranes shows phase separation of nylon and chitosan. As nylon content increases, the nylon phase on the membrane surface increases and thereby enhances cell adhesion. The opposite trend for cell adhesion and spheroid formation substantiates our hypothesis of spheroid formation on biomaterials: a balance between cell-substrate interaction and cell-cell interaction. The decrease in cell-substrate interaction tilts the balance to a state more favorable for spheroid formation. Our work can serve as a model to investigate the relative strengths of cell-cell and cell-substrate interactions and also pave way to design blended membranes with desired physical properties while preserving the spheroid-forming activity.

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Quantitative evaluation of midpalatal suture maturation via fractal analysis

    PubMed Central

    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 < 0.001). Fractal dimension was a statistically significant indicator of dichotomous results with regard to maturation stage (area under curve = 0.794, p < 0.001). A test in which 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

  20. Mechanical Behavior of Bio-inspired Model Suture Joints

    NASA Astrophysics Data System (ADS)

    Li, Yaning; Lin, Erica; Ortiz, Christine; Boyce, Mary

    2012-02-01

    Suture joints of varying degrees of geometric complexity are prevalent throughout nature as a means of joining structural elements while providing locally tailored mechanical performance. Here, micromechanical models of general trapezoidal waveforms of varying hierarchy are formulated to reveal the role of geometric complexity in governing stiffness, strength, toughness and corresponding deformation and failure mechanisms. Physical constructs of model composite suture systems are fabricated via multi-material 3D printing (Object Connex500). Tensile tests are conducted on samples covering a range in geometry, thus providing quantitative measures of stiffness, strength, and failure. The experiments include direct visualization of the deformation and failure mechanisms and their progression, as well as their dependence on suture geometry, showing the interplay between shear and tension/compression of the interfacial layers and tension of the skeletal teeth and the transition in failure modes with geometry. The results provide quantitative guidelines for the design and tailoring of suture geometry to achieve the desired mechanical properties and also facilitate understanding of suture growth and fusion, and evolutionary phenotype.

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

    PubMed Central

    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.

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

    PubMed

    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.

  3. Effect of nylon bag and protozoa on in vitro corn starch disappearance.

    PubMed

    van Zwieten, J T; van Vuuren, A M; Dijkstra, J

    2008-03-01

    An in vitro experiment was carried out to study whether the presence of protozoa in nylon bags can explain the underestimation of the in situ degradation of slowly degradable starch. Corn of a high (flint) and a low (dent) vitreousness variety was ground over a 3-mm screen, weighed in nylon bags with a pore size of 37 microm, and washed in cold water. Samples of washed cornstarch were incubated in 40-mL tubes with faunated and defaunated ruminal fluid. An additional amount of washed corn, in nylon bags, was inserted in each incubation tube. Incubations were carried out for 0, 2, 4, 6, 12, and 24 h, and starch residue in tube and nylon bag was determined. In general, starch disappearance from the nylon bag was less than from the tube, and was less with faunated than defaunated rumen fluid, but corn variety did not affect starch disappearance. When no protozoa were present, the disappearance of starch from the bags was higher after 6 and 12 h incubation compared with presence of protozoa. However, in the tubes, there was no difference in starch disappearance due to presence or absence of protozoa. Estimated lag time was higher in presence (4.6 h) then absence (3.6 h) of protozoa. It was concluded that the effect of presence or absence of protozoa on starch disappearance differs within or outside nylon bags. The reduced disappearance rate of starch inside the nylon bags in the presence of protozoa helps to explain the underestimation of starch degradation based on the in sacco procedure when compared with in vivo data upon incubation of slowly degradable starch sources.

  4. Nylon filament coated with paraffin for intraluminal permanent middle cerebral artery occlusion in rats.

    PubMed

    Zuo, Xia-Lin; Wu, Ping; Ji, Ai-Min

    2012-06-21

    A variety of intraluminal nylon filament has been used in rat middle cerebral artery occlusion (MCAO) models. However the lesion extent and its reproducibility vary among laboratories. The properties of nylon filament play a part of reasons for these variations. In the present study, we used paraffin-coated nylon filament for rat MCAO model, tested the effects and advanced improvement for making the rat MCAO. Forty male Sprague-Dawley (SD) rats were randomized into two groups, MCAO with traditional uncoated nylon filament (uMCAO) and MCAO with paraffin-coated nylon filament (cMCAO), three rats as normal group and sham group respectively. Assessment included mortality rates, model success rates, neurological deficit evaluation, and infarct volume. The study showed two rats died in uMCAO group, no rat died in cMCAO group within the 12h. The model success rate of uMCAO was 100%, while the uMCAO group was 55% (n=20, two died within 12h, seven rats were excluded as the brain slices showed no TTC staining due to subarachanoid hemorrhage). Neurological evaluation demonstrated group cMCAO had more worse neurological outcomes than group uMCAO, and the difference was statistically signification (p<0.05). TTC staining cMCAO group had significantly larger infarct volumes than uMCAO group, and also showed statistically significant difference (p<0.05). The result demonstrated that the paraffin-coated nylon filament intraluminal occlusion provide better occlusion of middle cerebral artery than the uncoated nylon filament, improve the consistent of model, and raise the success rate to reduce the number of experimental animals. These positive results are much encouraging and interesting.

  5. Reinforcement of nylon 6,6/nylon 6,6 grafted nanodiamond composites by in situ reactive extrusion

    NASA Astrophysics Data System (ADS)

    Choi, Eun-Yeob; Kim, Kiho; Kim, Chang-Keun; Kang, Eunah

    2016-11-01

    Nanodiamond (ND), an emerging new carbon material, was exploited to reinforce nylon 6,6 (PA66) polymer composites. Surface modified nanodiamonds with acyl chloride end groups were employed to chemically graft into PA66, enhancing the interfacial adhesion and thus the mechanical properties. The ND grafted PA66 (PA66-g-ND) reinforced PA66 composite prepared by in situ reactive extrusion exhibited increased tensile strength and modulus. The tensile strength and modulus of PA66/3 wt.% PA66-g-ND composites were enhanced by 11.6 and 20.8%, respectively when compared to those of the bare PA66 matrix. Even the PA66/pristine ND composites exhibited enhanced mechanical properties. The PA66-g-ND and the homogeneously dispersed PA66-g-ND in PA66 matrix were examined using X-ray photoelectron spectroscopy, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy techniques. The mechanical properties and thermal conductivities of the nanodiamond incorporated PA66 composites were also explored. The enhanced mechanical properties and thermal conductivities of the PA66-g-ND/PA66 composites make them potential materials for new applications as functional engineered thermoplastics.

  6. Reinforcement of nylon 6,6/nylon 6,6 grafted nanodiamond composites by in situ reactive extrusion

    PubMed Central

    Choi, Eun-Yeob; Kim, Kiho; Kim, Chang-Keun; Kang, Eunah

    2016-01-01

    Nanodiamond (ND), an emerging new carbon material, was exploited to reinforce nylon 6,6 (PA66) polymer composites. Surface modified nanodiamonds with acyl chloride end groups were employed to chemically graft into PA66, enhancing the interfacial adhesion and thus the mechanical properties. The ND grafted PA66 (PA66-g-ND) reinforced PA66 composite prepared by in situ reactive extrusion exhibited increased tensile strength and modulus. The tensile strength and modulus of PA66/3 wt.% PA66-g-ND composites were enhanced by 11.6 and 20.8%, respectively when compared to those of the bare PA66 matrix. Even the PA66/pristine ND composites exhibited enhanced mechanical properties. The PA66-g-ND and the homogeneously dispersed PA66-g-ND in PA66 matrix were examined using X-ray photoelectron spectroscopy, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy techniques. The mechanical properties and thermal conductivities of the nanodiamond incorporated PA66 composites were also explored. The enhanced mechanical properties and thermal conductivities of the PA66-g-ND/PA66 composites make them potential materials for new applications as functional engineered thermoplastics. PMID:27841314

  7. Is the Kapuskasing structure the site of a cryptic suture

    NASA Technical Reports Server (NTRS)

    Burke, K.

    1983-01-01

    The demonstration that the Kapuskasing structure involves substantial thrusting of deep continental crustal rocks over shallower continental rocks calls into question an earlier suggestion (by Wilson) that the Circum-Ungaua suture zone continued through the Kapuskasing to join the Penokean fold belt (implying that the Kapuskasing marked the site of what has since come to be called a cryptic suture). Problems are discussed which arose in attempting to reconcile Wilson's idea with data from more recent studies: whether the Kapuskasing and the Thompson belt both mark sutures of about 1700 Ma age; why there is no age difference across the Kapuskasing if it does mark the site of continental collision, and why there is no offset of Superior subprovinces across the Kapuskasing.

  8. Force-Induced Craniosynostosis in the Murine Sagittal Suture

    PubMed Central

    Oppenheimer, Adam J.; Rhee, Samuel T.; Goldstein, Steven A.; Buchman, Steven R.

    2010-01-01

    BACKGROUND The etiology of non-syndromic craniosynostosis remains elusive. While compressive forces have been implicated in premature suture fusion, conclusive evidence of force-induced craniosynostosis is lacking. The purpose of this study was to determine if cyclical loading of the murine calvarium could induce suture fusion. METHODS Calvarial coupons from post-natal day 21, B6CBA wild-type mice (n = 18) were harvested and cultured. A custom appliance capable of delivering controlled, cyclical, compressive loads was applied perpendicular to the sagittal suture within the coupon in vitro. Nine coupons were subjected to 0.3g of force for 30 minutes each day for a total of 14 days. A control group of nine coupons was clamped in the appliance without loading. Analysis of suture phenotype was performed using alkaline phosphatase and H&E staining techniques, as well as in situ hybridization analysis using Bone Sialoprotein (BSP). RESULTS Control group sagittal sutures—which normally remain patent in mice—showed their customary histological appearance. In contradistinction, sagittal sutures subjected to cyclic loading showed histological evidence of premature fusion (craniosynostosis). In addition, alkaline phosphatase activity and BSP expression was observed to be increased in the experimental group when compared to matched controls. CONCLUSIONS An in vitro model of forced-induced craniosynostosis has been devised. Premature fusion of the murine sagittal suture was induced with the application of controlled, cyclical, compressive loads. These results implicate abnormal forces in the development of non-syndromic craniosynostosis, which supports our global hypothesis that epigenetic phenomena have a crucial role in the pathogenesis of craniosynostosis. PMID:19952640

  9. Influence of metopic suture fusion associated with sagittal synostosis.

    PubMed

    Domeshek, Leahthan F; Das, Rajesh R; Van Aalst, John A; Mukundan, Srinivasan; Marcus, Jeffrey R

    2011-01-01

    Some patients with sagittal synostosis present with a fused metopic suture. We hypothesize that premature metopic suture fusion consistently and identifiably alters form associated with sagittal synostosis. We previously validated three-dimensional vector analysis as a tool for the study of cranial morphology and used it herein to distinguish between dysmorphologies of isolated sagittal synostosis (ISS) and combined sagittal-metopic synostosis (CSM). Preoperative computed tomographic scans for patients with ISS and CSM were compared with matched normative counterparts. Premature metopic suture fusion was defined by established radiographic criteria. Color-coded point clouds were created for each scan, with color gradient based on patient deviation from normal across the dysmorphic skull. Standard deviation data were evaluated in 7 cranial regions and compared between ISS and CSM. Mean ISS and CSM point clouds were evaluated. Using three-dimensional vector analysis, standard anthropometric data/indices were determined and compared between the 2 groups. Differences in ISS and CSM regional deviations and index measurements were not statistically significant. Mean ISS and CSM representations depicted similar overall morphology. Using accepted criteria for identification of metopic synostosis in CSM, only subtle differences appear between the 2 populations on average. Expected morphologic changes associated with metopic synostosis are present in only a small number of patients with CSM, arguing against our hypothesis, and calling into question the criteria used to identify premature metopic suture fusion. Normal metopic suture fusion occurs for a continuum of time. Our findings suggest that the normal continuum may begin earlier than the literature suggests. In the setting of sagittal synostosis, the influence of metopic suture fusion and treatment is best determined by individual morphologic analysis.

  10. EELS Analysis of Nylon 6 Nanofibers Reinforced with Nitroxide-Functionalized Graphene Oxide.

    PubMed

    Leyva-Porras, César; Ornelas-Gutiérrez, C; Miki-Yoshida, M; Avila-Vega, Yazmín I; Macossay, Javier; Bonilla-Cruz, José

    2014-01-01

    A detailed analysis by transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) of nitroxide-functionalized graphene oxide layers (GOFT) dispersed in Nylon 6 nanofibers is reported herein. The functionalization and exfoliation process of graphite oxide to GOFT was confirmed by TEM using electron diffraction patterns (EDP), wherein 1 to 4 graphene layers of GOFT were observed. The distribution and alignment of GOFT layers within a sample of Nylon 6 nanofiber reveals that GOFT platelets are mainly within the fiber, but some were partially protruding from it. Furthermore, Nylon 6 nanofibers exhibit an average diameter of 225 nm with several microns in length. GOFT platelets embedded into the fiber, the pristine fiber, and amorphous carbon were analyzed by EELS where each spectra [corresponding to the carbon edge (C-K)] exhibited changes in the fine structure, allowing a clear distinction between: i) GOFT single-layers, ii) Nylon-6 nanofibers, and iii) the carbon substrate. EELS analysis is presented here for the first time as a powerful tool to identify functionalized graphene single-layers (< 4 layers of GOFT) into a Nylon 6 nanofiber composite.

  11. EELS Analysis of Nylon 6 Nanofibers Reinforced with Nitroxide-Functionalized Graphene Oxide

    PubMed Central

    Leyva-Porras, César; Ornelas-Gutiérrez, C.; Miki-Yoshida, M.; Avila-Vega, Yazmín I.; Macossay, Javier; Bonilla-Cruz, José

    2014-01-01

    A detailed analysis by transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) of nitroxide-functionalized graphene oxide layers (GOFT) dispersed in Nylon 6 nanofibers is reported herein. The functionalization and exfoliation process of graphite oxide to GOFT was confirmed by TEM using electron diffraction patterns (EDP), wherein 1 to 4 graphene layers of GOFT were observed. The distribution and alignment of GOFT layers within a sample of Nylon 6 nanofiber reveals that GOFT platelets are mainly within the fiber, but some were partially protruding from it. Furthermore, Nylon 6 nanofibers exhibit an average diameter of 225 nm with several microns in length. GOFT platelets embedded into the fiber, the pristine fiber, and amorphous carbon were analyzed by EELS where each spectra [corresponding to the carbon edge (C-K)] exhibited changes in the fine structure, allowing a clear distinction between: i) GOFT single-layers, ii) Nylon-6 nanofibers, and iii) the carbon substrate. EELS analysis is presented here for the first time as a powerful tool to identify functionalized graphene single-layers (< 4 layers of GOFT) into a Nylon 6 nanofiber composite. PMID:24634536

  12. Comparison of computed tomography dose index in polymethyl methacrylate and nylon dosimetry phantoms

    PubMed Central

    Sookpeng, Supawitoo; Cheebsumon, Patsuree; Pengpan, Thanyawee; Martin, Colin

    2016-01-01

    The use of computed tomography (CT) scanning has been growing steadily. Therefore, CT dose measurement is becoming increasingly important for patient protection and optimization. A phantom is an important tool for dose measurement. This paper focuses on the evaluation of a CT dosimetry phantom made from nylon, instead of the standard polymethyl methacrylate (PMMA), which is not readily available or is too expensive in some countries. Comparison between phantoms made from the two materials is made in terms of measurements of the CT dose indices (CTDI). These were measured for four different beam widths and kVp settings at the center and periphery in head and body phantoms made from both materials and weighted CTDIs (CTDIw) were calculated. CT numbers along the z-axis of the phantom were also measured at the center and four peripheral positions of each scanned slice to check phantom homogeneity. Results showed that values for the CTDIw measured in the nylon phantoms were slightly higher than those from the PMMA while CT numbers for nylon were lower than those of PMMA. This is because the mass attenuation coefficient of the nylon is higher. Nylon could be used as a substitute material for CT dosimetry phantom to enable measurements and adjustment factors are given which could be used to estimate PMMA values for making comparisons with displayed values. PMID:27051170

  13. Polymer chain length effects on fibroblast attachment on nylon-3-modified surfaces.

    PubMed

    Liu, Runhui; Masters, Kristyn S; Gellman, Samuel H

    2012-04-09

    Nylon-3 polymers have a polyamide backbone reminiscent of that found in proteins (β- vs α-amino acid residues, respectively), which makes these materials interesting for biological applications. Because of the versatility of the ring-opening polymerization process and the variety of β-lactam starting materials available, the structure of nylon-3 copolymers is highly amenable to alteration. A previous study showed that relatively subtle changes in the structure or ratio of hydrophobic and cationic subunits that comprise these polymers can result in significant changes in the ability of nylon-3-bearing surfaces to support cell adhesion and spreading. In the present study, we have exploited the highly tailorable nature of these polymers to synthesize new versions possessing a wide range of chain lengths, with the intent of optimizing these materials for use as cell-supportive substrates. We find that longer nylon-3 chains lead to better fibroblast attachment on modified surfaces and that at the optimal chain lengths less hydrophobic subunits are superior. The best polymers we identified are comparable to an RGD-containing peptide in supporting fibroblast attachment. The results described here will help to focus future efforts aimed at refining nylon-3 copolymer substrates for specific tissue engineering applications.

  14. Experimental and computational analysis of cellular interactions with nylon-3-bearing substrates.

    PubMed

    Liu, Runhui; Vang, Kang Z; Kreeger, Pamela K; Gellman, Samuel H; Masters, Kristyn S

    2012-10-01

    The ability to design biomaterials that interact with biological environments in a predictable manner necessitates an improved understanding of how surface chemistry influences events such as protein adsorption and cell adhesion. In this work, we examined mechanisms governing the interactions between 3T3 fibroblasts and nylon-3 polymers, which have a protein-like polyamide backbone and are highly amenable to tuning of chemical and physical properties. Protein adsorption and cell adhesion to a library of nylon-3 polymers were characterized and analyzed by partial least squares regression. This analysis revealed that specific chemical features of the nylon-3 polymers correlated with the extent of protein adsorption, which, in turn, correlated with cell adhesion in a serum-containing environment. In contrast, in a serum-free environment, cell adhesion could be predicted solely from chemical properties. Enzymatic treatments of 3T3 cells before plating indicated that proteins bound to the cell surface mediated cell-nylon-3 polymer interactions under serum-free conditions, with additional analysis suggesting that cell-associated fibronectin played a dominant role in adhesion in the absence of serum. The mechanistic insight gained from these studies can be used to inform the design of new polymer structures in addition to providing a basis for continued development of nylon-3 copolymers for tissue engineering applications.

  15. Nylon and teflon scribe effect on NBR to Chemlok 233 and NBR to NBR bond interfaces

    NASA Technical Reports Server (NTRS)

    Jensen, S. K.

    1990-01-01

    A study was requested by Manufacturing Engineering to determine what effects marking with nylon (6/6) and Teflon scribes may have on subsequent bonding. Witness panel bond specimens were fabricated by the development lab to test both acrylonitrile butadiene rubber (NBR) to Chemlok and NBR to NBR after controlled exposure. The nylon rod used as a scribe tool demonstrates virtually no bond deterioration when used to scribe lines on either the Chemlok to NBR surfaces or the NBR to NBR interface. Lab test results indicate that the nylon rod-exposed samples produce tensile and peel values very similar to the control samples and the Teflon exposed samples produce tensile and peel values much lower than the control samples. Visual observation of the failure surfaces of the tested samples shows that Teflon scribing produces an obvious contamination to the surface and the nylon produces no effect. Photographs of test samples are provided. It is concluded that Teflon stock used as a scribe tool on a Chemlok 233 to NBR surface or an NBR to NBR surface has a detrimental effect on the bond integrity on either of these bond interfaces. Therefore, it is recommended that the nylon rod continue to be used where a scribe line is required in the redesigned solid rocket motor segment insulation layup operations. The use of Teflon scribes should not be considered.

  16. A reusable suture anchor for arthroscopy psychomotor skills training.

    PubMed

    Tillett, Edward D; Rogers, Rainie; Nyland, John

    2003-03-01

    For residents to adequately develop the early arthroscopy psychomotor skills required to better learn how to manage the improvisational situations they will encounter during actual patient cases, they need to experience sufficient practice repetitions within a contextually relevant environment. Unfortunately, the cost of suture anchors can be a practice repetition-limiting factor in learning arthroscopic knot-tying techniques. We describe a technique for creating inexpensive reusable suture anchors and provide an example of their application to repair the anterior glenoid labrum during an arthroscopy psychomotor skills laboratory training session.

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

    SciTech Connect

    Reginato, A.J.; Schiapachasse, V.; Guerrero, R.

    1982-05-01

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

  18. Bone Plug Versus Suture-Only Fixation of Meniscal Grafts

    PubMed Central

    Wang, Hongsheng; Gee, Albert O.; Hutchinson, Ian D.; Stoner, Kirsten; Warren, Russell F.; Chen, Tony O.; Maher, Suzanne A.

    2014-01-01

    Background Meniscus allograft transplantation (MAT) is primarily undertaken to relieve the symptoms associated with meniscal deficiencies. However, its ability to restore normal knee joint contact mechanics under physiological loads is still unclear. Purpose To quantify the dynamic contact mechanics associated with 2 commonly used fixation techniques in MAT of the medial compartment: transosseous suture fixation via bone plugs and suture-only fixation at the horns. Study Design Controlled laboratory study. Methods Physiological loads to mimic gait were applied across 7 human cadaveric knees on a simulator. A sensor placed on the medial tibial plateau recorded dynamic contact stresses under the following conditions: (1) intact meniscus, (2) MAT using transosseous suture fixation via bone plugs at the anterior and posterior horns, (3) MAT using suture-only fixation, and (4) total medial meniscectomy. A “remove-replace” procedure was performed to place the same autograft for both MAT conditions to minimize the variability in graft size, geometry, and material property and to isolate the effects of the fixation technique. Contact stress, contact area, and weighted center of contact stress (WCoCS) were quantified on the medial plateau throughout the stance phase. Results Knee joint contact mechanics were sensitive to the meniscal condition primarily during the first half of the gait cycle. After meniscectomy, the mean peak contact stress increased from 4.2 ± 1.2 MPa to 6.2 ± 1.0 MPa (P = .04), and the mean contact area decreased from 546 ± 132 mm2 to 192 ± 122 mm2 (P = .01) compared with the intact meniscus during early stance (14% of the gait cycle). After MAT, the mean contact stress significantly decreased with bone plug fixation (5.0 ± 0.7 MPa) but not with suture-only fixation (5.9 ± 0.7 MPa). Both fixation techniques partially restored the contact area, but bone plug fixation restored it closer to the intact condition. The location of WCoCS in the

  19. Preparation of scaffolds based on bulky sutures for cell therapy

    NASA Astrophysics Data System (ADS)

    Park, Young Hwan; Chun, Heung Jae; Kim, Sung Jin

    2012-04-01

    Scaffold for cell therapy was prepared with poly (lactide-co-glicolide, PLA/PGA (10:90). By using melt-spinning and draw texturing process, we could prepare microfibrous bulky suture which had heterogeneous macropore. Microfibrous structure has great potentiality as biomimicking architecture for cell growth and maintaining cell functions. The result of cell seeding showed that pore size, pore distribution, and fiber fineness of sutures were suitable as a biocompatible scaffold in vitro for NIH 3T3 Fibroblast cell. Also, we expect that prepared scaffold for cell-therapy will provide numerous benefits as a noninvasive alternative for tissue engineering applications.

  20. Preparation of scaffolds based on bulky sutures for cell therapy

    NASA Astrophysics Data System (ADS)

    Park, Young Hwan; Chun, Heung Jae; Kim, Sung Jin

    2011-11-01

    Scaffold for cell therapy was prepared with poly (lactide-co-glicolide, PLA/PGA (10:90). By using melt-spinning and draw texturing process, we could prepare microfibrous bulky suture which had heterogeneous macropore. Microfibrous structure has great potentiality as biomimicking architecture for cell growth and maintaining cell functions. The result of cell seeding showed that pore size, pore distribution, and fiber fineness of sutures were suitable as a biocompatible scaffold in vitro for NIH 3T3 Fibroblast cell. Also, we expect that prepared scaffold for cell-therapy will provide numerous benefits as a noninvasive alternative for tissue engineering applications.

  1. Mechanical Properties of Laser-Sintered-Nylon Diamond Lattices

    NASA Astrophysics Data System (ADS)

    Neff, Clayton

    Additive manufacturing offers a manufacturing technique to produce complex geometry prototypes at a rapid pace and low cost. These advantages advocate additive manufacturing for the design and production of cellular structures. Cellular structures are interesting because they contain a large amount of porosity (void space of air) to manifest a lightweight structure. Designs of cellular structures generate a periodic pattern; often of complex geometry, called a lattice. There has been a significant amount of research to maximize specific stiffness of lattice structures but little to evaluate low-stiffness lattices. Low-stiffness structures benefit energy absorbance through bending of the lattice. This research seeks to assess diamond lattices as low stiffness, bending structures. The research involves PA2200 (Nylon 12) laser sintered diamond lattices with experimental compression testing and direct FEA model comparison. A correction factor is applied for a design offset of laser sintered lattices. Once applied, the experimental and FEA data agree in validating the diamond lattice as a bending-dominated structure. Diamond lattices show a 4th order relationship between stiffness and parameters of thickness and unit cell length. For density, stiffness maintains a 2nd order relationship, as predicted by bending dominated structures. The resulting stiffness can be tuned over a stiffness range of four orders of magnitude. Further research shows the results for modifying the diamond lattice and scaling stiffness and density using other materials (like metals) to expand the range of stiffness and compare diamond lattices on material property charts. Lastly, the effective Poisson's ratio varies from 0.5 to 0.4 depending on the (t/L) ratio.

  2. Endotracheal tube fixation methods for optimal stability: a comparison of adhesive tape, suture, and tape-suture fixation.

    PubMed

    Farbod, Frank; Tuli, Puneet; Robertson, Bernard F; Jackson, Ian T

    2010-07-01

    Accidental extubation of an intubated patient is a serious consideration in the surgical patient. Adequate fixation in the intubated patient is essential to prevent potentially life-threatening complications. Several methods of endotracheal tube fixation have been described in the literature. In this study, we examine 3 common methods of fixation: adhesive tape alone, suture, and tape-suture. Testing occurred in a laboratory setting with 2 fresh cadavers. Endotracheal tubes were inserted, using the methods of fixation in question. We subjected each fixation technique to progressively increasing weight to determine which technique is most resistant to accidental removal. We found that fixation of the tube by combining tape around the tube with a suture through the tape is the best noninvasive technique of the 3 methods evaluated in cases where movement of the head is anticipated.

  3. Biomechanical Comparison of Modified Suture Bridge Using Rip-Stop versus Traditional Suture Bridge for Rotator Cuff Repair.

    PubMed

    Wu, ZiYing; Zhang, Chong; Zhang, Peng; Chen, TianWu; Chen, ShiYi; Chen, JiWu

    2016-01-01

    Purpose. To compare the biomechanical properties of 3 suture-bridge techniques for rotator cuff repair. Methods. Twelve pair-matched fresh-frozen shoulder specimens were randomized to 3 groups of different repair types: the medially Knotted Suture Bridge (KSB), the medially Untied Suture Bridge (USB), and the Modified Suture Bridge (MSB). Cyclic loading and load-to-failure test were performed. Parameters of elongation, stiffness, load at failure, and mode of failure were recorded. Results. The MSB technique had the significantly greatest load to failure (515.6 ± 78.0 N, P = 0.04 for KSB group; P < 0.001 for USB group), stiffness (58.0 ± 10.7 N/mm, P = 0.005 for KSB group; P < 0.001 for USB group), and lowest elongation (1.49 ± 0.39 mm, P = 0.009 for KSB group; P = 0.001 for USB group) among 3 groups. The KSB repair had significantly higher ultimate load (443.5 ± 65.0 N) than USB repair (363.5 ± 52.3 N, P = 0.024). However, there was no statistical difference in stiffness and elongation between KSB and USB technique (P = 0.396 for stiffness and P = 0.242 for elongation, resp.). The failure mode for all specimens was suture pulling through the cuff tendon. Conclusions. Our modified suture bridge technique (MSB) may provide enhanced biomechanical properties when compared with medially knotted or knotless repair. Clinical Relevance. Our modified technique may represent a promising alternative in arthroscopic rotator cuff repair.

  4. Biomechanical Comparison of Modified Suture Bridge Using Rip-Stop versus Traditional Suture Bridge for Rotator Cuff Repair

    PubMed Central

    Zhang, Peng; Chen, TianWu; Chen, ShiYi

    2016-01-01

    Purpose. To compare the biomechanical properties of 3 suture-bridge techniques for rotator cuff repair. Methods. Twelve pair-matched fresh-frozen shoulder specimens were randomized to 3 groups of different repair types: the medially Knotted Suture Bridge (KSB), the medially Untied Suture Bridge (USB), and the Modified Suture Bridge (MSB). Cyclic loading and load-to-failure test were performed. Parameters of elongation, stiffness, load at failure, and mode of failure were recorded. Results. The MSB technique had the significantly greatest load to failure (515.6 ± 78.0 N, P = 0.04 for KSB group; P < 0.001 for USB group), stiffness (58.0 ± 10.7 N/mm, P = 0.005 for KSB group; P < 0.001 for USB group), and lowest elongation (1.49 ± 0.39 mm, P = 0.009 for KSB group; P = 0.001 for USB group) among 3 groups. The KSB repair had significantly higher ultimate load (443.5 ± 65.0 N) than USB repair (363.5 ± 52.3 N, P = 0.024). However, there was no statistical difference in stiffness and elongation between KSB and USB technique (P = 0.396 for stiffness and P = 0.242 for elongation, resp.). The failure mode for all specimens was suture pulling through the cuff tendon. Conclusions. Our modified suture bridge technique (MSB) may provide enhanced biomechanical properties when compared with medially knotted or knotless repair. Clinical Relevance. Our modified technique may represent a promising alternative in arthroscopic rotator cuff repair. PMID:27975065

  5. Interfacial adhesion in rayon/nylon sheath/core composite fibers

    SciTech Connect

    Tao Weiying.

    1991-01-01

    The fibers with enhanced adhesion were produced using a wire coating type process. One objective was to determine an effective coupling agent and the most-appropriate application conditions for maximum interfacial adhesion in the rayon/nylon bicomponent fibers. The second objective was to characterize the interfacial adhesion between the core fiber and the rayon skin. After removal of the spin finish by water washing, the nylon core fibers were pretreated with fumaric acid (FA) as an adhesion promoter and then were coated with viscose rayon. The results indicated that the interfacial adhesion in the rayon/nylon composite fibers was significantly improved under the application conditions of 1.0% with 36 second pretreatment time, 1.5% with 18 second pretreatment, and 2% with 9 second pretreatment time. A fiber pull adhesion test method was developed to test the interfacial adhesion. This method effectively determined the adhesion between the core and the skin.

  6. Nylon-3 polymers active against drug-resistant Candida albicans biofilms.

    PubMed

    Liu, Runhui; Chen, Xinyu; Falk, Shaun P; Masters, Kristyn S; Weisblum, Bernard; Gellman, Samuel H

    2015-02-18

    Candida albicans is the most common fungal pathogen in humans, and most diseases produced by C. albicans are associated with biofilms. We previously developed nylon-3 polymers with potent activity against planktonic C. albicans and excellent C. albicans versus mammalian cell selectivity. Here we show that these nylon-3 polymers have strong and selective activity against drug-resistant C. albicans in biofilms, as manifested by inhibition of biofilm formation and by killing of C. albicans in mature biofilms. The best nylon-3 polymer (poly-βNM) is superior to the antifungal drug fluconazole for all three strains examined. This polymer is slightly less effective than amphotericin B (AmpB) for two strains, but the polymer is superior against an AmpB-resistant strain.

  7. Coating individual single-walled carbon nanotubes with nylon 6,10 through emulsion polymerization.

    PubMed

    Chen, Wei-Chiang; Wang, Randy K; Ziegler, Kirk J

    2009-08-01

    Solvent microenvironments are formed around individual single-walled carbon nanotubes (SWNTs) by mixing SWNT suspensions with water-immiscible organic solvents. These microenvironments are used to encapsulate the SWNTs with the monomer sebacoyl chloride. Hexamethylene diamine is then injected into the aqueous phase so the formation of nylon 6,10 is restricted to the interface between the microenvironment and water. This emulsion polymerization process results in uniform coatings of nylon 6,10 around individual SWNTs. The nylon-coated SWNTs remain dispersed in the aqueous phase and are highly luminescent at pH values ranging from 3 to 12. This emulsion polymerization method provides a general approach to coat nanotubes with various polymers.

  8. Fabrication and characterization of silver- and copper-coated Nylon 6 forcespun nanofibers by thermal evaporation

    SciTech Connect

    Mihut, Dorina M. Lozano, Karen; Foltz, Heinrich

    2014-11-01

    Silver and copper nanoparticles were deposited as thin films onto substrates consisting of Nylon 6 nanofibers manufactured using forcespinning{sup ®} equipment. Different rotational speeds were used to obtain continuous nanofibers of various diameters arranged as nonwoven mats. The Nylon 6 nanofibers were collected as successive layers on frames, and a high-vacuum thermal evaporation method was used to deposit the silver and copper thin films on the nanofibers. The structures were investigated using scanning electron microscopy–scanning transmission electron microscopy, atomic force microscopy, x-ray diffraction, and electrical resistance measurements. The results indicate that evaporated silver and copper nanoparticles were successfully deposited on Nylon 6 nanofibers as thin films that adhered well to the polymer substrate while the native morphology of the nanofibers were preserved, and electrically conductive nanostructures were achieved.

  9. Modeling and flow analysis of pure nylon polymer for injection molding process

    NASA Astrophysics Data System (ADS)

    Nuruzzaman, D. M.; Kusaseh, N.; Basri, S.; Oumer, A. N.; Hamedon, Z.

    2016-02-01

    In the production of complex plastic parts, injection molding is one of the most popular industrial processes. This paper addresses the modeling and analysis of the flow process of the nylon (polyamide) polymer for injection molding process. To determine the best molding conditions, a series of simulations are carried out using Autodesk Moldflow Insight software and the processing parameters are adjusted. This mold filling commercial software simulates the cavity filling pattern along with temperature and pressure distributions in the mold cavity. In the modeling, during the plastics flow inside the mold cavity, different flow parameters such as fill time, pressure, temperature, shear rate and warp at different locations in the cavity are analyzed. Overall, this Moldflow is able to perform a relatively sophisticated analysis of the flow process of pure nylon. Thus the prediction of the filling of a mold cavity is very important and it becomes useful before a nylon plastic part to be manufactured.

  10. The relative efficiency of nylon and cotton gill nets for taking lake trout in Lake Superior

    USGS Publications Warehouse

    Pycha, Richard L.

    1962-01-01

    The change from cotton to nylon twine for gill nets in 1949–52 resulted in a sharp increase in the efficiency of the most important gear used for taking lake trout in Lake Superior, and, consequently, biased estimates of fishing intensity and abundance severely.From early May to the end of September 1961, short gangs (2000 or 4000 linear feet) of cotton and nylon nets were fished in parallel sets for lake trout. A total of 343,000 feet of gill netting was lifted. Nylon nets were 2.25 times as efficient as cotton nets for taking legal-sized fish and 2.8 times as efficient for undersized lake trout. The average lengths of legal, undersized, and all lake trout taken in nets of the two materials did not differ greatly. The percentage of the catch which was undersized (less than 1.25 lb, dressed weight) was 20.8 in nylon nets and 17.7 in cotton. The relative efficiency of cotton and nylon nets showed no trend during the season. The efficiency ratio determined in this study was closely similar to that obtained by earlier workers.Correction of estimates of fishing intensity and abundance for the greater efficiency of the nylon nets used since 1951 has not been attempted. The drastic decline of the lake trout fishery has forced fishermen to make changes in fishing practices in the past few years that cause new bias of an unknown extent to estimates of fishing intensity.

  11. 21 CFR 878.5010 - Nonabsorbable polypropylene surgical suture.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nonabsorbable polypropylene surgical suture. 878.5010 Section 878.5010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... a monofilament, nonabsorbable, sterile, flexible thread prepared from long-chain polyolefin...

  12. 21 CFR 878.5010 - Nonabsorbable polypropylene surgical suture.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nonabsorbable polypropylene surgical suture. 878.5010 Section 878.5010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... a monofilament, nonabsorbable, sterile, flexible thread prepared from long-chain polyolefin...

  13. 21 CFR 878.5010 - Nonabsorbable polypropylene surgical suture.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nonabsorbable polypropylene surgical suture. 878.5010 Section 878.5010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... a monofilament, nonabsorbable, sterile, flexible thread prepared from long-chain polyolefin...

  14. 21 CFR 878.5010 - Nonabsorbable polypropylene surgical suture.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonabsorbable polypropylene surgical suture. 878.5010 Section 878.5010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... a monofilament, nonabsorbable, sterile, flexible thread prepared from long-chain polyolefin...

  15. Use of Absorbable Sutures in Canine Carotid Arteries

    PubMed Central

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

    1990-01-01

    To study the functional and microstructural characteristics of polydioxanone sutures in vascular surgery, we created 48 vascular anastomoses in the right and left common carotid arteries of 24 mongrel dogs. In each animal, polydioxanone sutures were used in 1 carotid artery, and polypropylene sutures were used in the contralateral carotid artery. Twelve groups of 2 animals each were then formed. The 1st group was observed for 1 month, the 2nd for 2 months, the 3rd for 3 months, and so on until the 12th group, which was observed for 12 months. At the end of each observation period, reoperation was undertaken to evaluate the vascular anastomoses by means of angiography and microscopy. The polypropylene anastomoses showed a marked deformity, with tissue retraction and a foreign body reaction. In contrast, the polydioxanone anastomoses exhibited satisfactory healing, without deformity, and were well tolerated histologically. We believe that polydioxanone may be a useful, alternative vascular suture material. (Texas Heart Institute Journal 1990;17:99-102) Images PMID:15227391

  16. [Making easier what is difficult: continuous suture in intracorporeal anastomosis].

    PubMed

    Ferrer-Márquez, Manuel; Belda-Lozano, Ricardo; Solvas-Salmerón, María José; Ferrer-Ayza, Manuel

    2014-01-01

    Bariatric surgery requires a high level of training and detailed knowledge of advanced laparoscopy, especially when carrying out intracorporeal anastomosis. The following presentation shows two examples used by our group, which consists of slipknots done at the beginning and the end of the thread that allows us to do the suture quickly and securely.

  17. 21 CFR 870.3460 - Endovascular Suturing System.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Endovascular Suturing System. 870.3460 Section 870.3460 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3460 Endovascular...

  18. 21 CFR 870.3460 - Endovascular Suturing System.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Endovascular Suturing System. 870.3460 Section 870.3460 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3460 Endovascular...

  19. 21 CFR 870.3460 - Endovascular Suturing System.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Endovascular Suturing System. 870.3460 Section 870.3460 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3460 Endovascular...

  20. Modified Margin Convergence: Over-Under Lacing Suture Technique

    PubMed Central

    Métais, Pierre; Lanzone, Roberto; Lim, Chauncey Kester; Albino, Paolo; Carbone, Stefano

    2015-01-01

    The principle of margin convergence can be applied to rotator cuff repair to enhance the security of fixation by decreasing the mechanical strain at the margins of the tear. We describe a suture technique, over-under lacing, that reproduces the same margin convergence, with equal tissue tension across the entire surface area of the cuff. A consecutive series of patients affected by massive U-shaped rotator cuff tears were treated by this repair technique. Preoperative diagnosis, tear assessment, and grading of fatty infiltration of the cuff muscles were based on arthro–computed tomography evaluation. The technique passes 2 sutures from the medial to lateral margin of the tear, with a knotless suture anchor for tendon-to-bone fixation. The proposed technique seems to reduce tensile strain on the repaired tendon, can reconstruct the rotator cuff cable, and can attain the balanced pull of the tendon in a medial-to-lateral fashion. The over-under lacing suture technique is both simple and reproducible. This technique may achieve the goals of margin convergence with satisfactory preliminary clinical results for patients with massive rotator cuff tears. PMID:26697304

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

    PubMed

    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.

  2. Angiogenesis and osteogenesis in an orthopedically expanded suture

    NASA Technical Reports Server (NTRS)

    Chang, H. N.; Garetto, L. P.; Potter, R. H.; Katona, T. R.; Lee, C. H.; Roberts, W. E.

    1997-01-01

    The purpose of this study was to examine the angiogenic and the subsequent osteogenic responses during a 96-hour time-course after sutural expansion. Fifty rats were divided into: (1) a control group that received only angiogenic induction through injection of 5 ng/gm recombinant human endothelial cell growth factor (rhECGF); (2) an experimental group that received orthopedic expansion and rhECGF; (3) a sham group that received expansion and sodium chloride (NaCl) injection; and (4) a baseline group that received no expansion or injection. All rats were injected with 3H-thymidine (1.0 microCi/gm) 1 hour before death to label the DNA of S-phase cells. Demineralized sections (4 microm thick) were stained with hematoxylin and eosin. Angiogenesis and cell migration were analyzed with a previously established cell kinetics model. Analysis of variance was used to test the hypothesis that enhancement of angiogenesis stimulates reestablishment of osteogenic capability. Blood vessel number, area, and endothelial cell-labeled index significantly increased in experimental groups, but no difference was found between control and baseline groups. Labeled-pericyte index and activated pericyte numbers in the experimental group were also higher than in the sham groups. These results show that supplemental rhECGF enhances angiogenesis in expanded sutures but not in nonexpanded sutures. Data also suggest that pericytes are the source of osteoblasts in an orthopedically expanded suture.

  3. Single-Suture Neochorda-Folding Plasty for Mitral Regurgitation

    PubMed Central

    Park, Jong Myung; Je, Hyung Gon; Lee, Sang Kwon

    2016-01-01

    The single-suture neochorda-folding plasty technique is a modification of existing mitral valve repair techniques. In the authors’ experience, its simplicity, reliability, and versatility make it a useful technique for mitral valve repair, especially when a minimally invasive approach is used. PMID:26889453

  4. 21 CFR 878.5010 - Nonabsorbable polypropylene surgical suture.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nonabsorbable polypropylene surgical suture. 878.5010 Section 878.5010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices §...

  5. 21 CFR 878.5030 - Natural nonabsorbable silk surgical suture.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Natural nonabsorbable silk surgical suture. 878.5030 Section 878.5030 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices §...

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

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Natural nonabsorbable silk surgical suture. 878.5030 Section 878.5030 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices §...

  7. 21 CFR 878.5030 - Natural nonabsorbable silk surgical suture.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Natural nonabsorbable silk surgical suture. 878.5030 Section 878.5030 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices §...

  8. 21 CFR 878.5030 - Natural nonabsorbable silk surgical suture.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Natural nonabsorbable silk surgical suture. 878.5030 Section 878.5030 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices §...

  9. 21 CFR 878.5030 - Natural nonabsorbable silk surgical suture.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Natural nonabsorbable silk surgical suture. 878.5030 Section 878.5030 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices §...

  10. 21 CFR 878.5020 - Nonabsorbable polyamide surgical suture.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nonabsorbable polyamide surgical suture. 878.5020 Section 878.5020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.5020...

  11. Cystoscopic suture removal by Holmium-YAG laser after Burch procedure.

    PubMed

    Karaşahin, Emre Kazım; Esin, Sertaç; Alanbay, Ibrahim; Ercan, Mutlu Cihangir; Mutlu, Erol; Başer, Iskender; Basal, Seref

    2011-01-01

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

  12. Mechanical force-induced midpalatal suture remodeling in mice

    PubMed Central

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

    2007-01-01

    Mechanical stress is an important epigenetic factor for regulating skeletal remodeling, and application of force can lead to remodeling of both bone and cartilage. Chondrocytes, osteoblasts and osteoclasts all participate and interact with each other in this remodeling process. To study cellular responses to mechanical stimuli in a system that can be genetically manipulated, we used mouse midpalatal suture expansion in vivo. 6-weeks-old male C57BL/6 mice were subjected to palatal suture expansion by opening loops with an initial force of 0.56N for periods of 1, 3, 7, 14 or 28 days. Periosteal cells in expanding sutures showed increased proliferation, with Ki67 positive cells representing 1.8±0.1% to 4.5±0.4% of total suture cells in control groups and 12.0±2.6% to 19.9±1.2% in experimental/expansion groups (p<0.05). Starting at day 1, cells expressing alkaline phosphatase and type I collagen were seen. New cartilage and bone formation was observed at the oral edges of the palatal bones at day 7; at the nasal edges only bone formation without cartilage appeared to occur. An increase in osteoclast numbers suggested increased bone remodeling, ranging from 60 to 160% throughout the experimental period. Decreased Saffranin O staining after day 3 suggested decreased proteoglycan content in the secondary cartilage. MicroCT showed a significant increase in maxillary width at days 14 and 28 (from 2334±4μm to 2485±3μm at day 14 and from 2383±5μm to 2574±7μm at day 28, p<0.001). The suture width was increased at days 14 and 28, except in the oral third region at day 28 (from 48±5μm to 36±4μm, p<0.05). Bone volume/total volume was significantly reduced at days 14 and 28 (50.2±0.7% vs. 68.0±3.7% and 56.5±1.0%vs. 60.9±1.3%, respectively, p<0.05), indicative of increased bone marrow space. These findings demonstrate that expansion forces across the midpalatal suture promote bone resorption through activation of osteoclasts and bone and cartilage formation via

  13. Comparison of silver nylon wound dressing and silver sulfadiazine in partial burn wound therapy.

    PubMed

    Abedini, Fereydoon; Ahmadi, Abdollah; Yavari, Akram; Hosseini, Vahid; Mousavi, Sarah

    2013-10-01

    The study aims to perform a comparative assessment of two types of burn wound treatment. To do the assessment, patients with partial thickness burn wounds with total body surface area <40% were simple randomised to treat with nanocrystalline silver nylon wound dressing or silver sulfadiazine cream. Efficacy of treatment, use of analgesics, number of wound dressing change, wound infection and final hospitalisation cost were evaluated. The study showed silver nylon wound dressing significantly reduced length of hospital stay, analgesic use, wound infection and inflammation compared with silver sulfadiazine.

  14. Accelerated biodegradation of silk sutures through matrix metalloproteinase activation by incorporating 4-hexylresorcinol

    PubMed Central

    Jo, You-Young; Kweon, HaeYong; Kim, Dae-Won; Kim, Min-Keun; Kim, Seong-Gon; Kim, Jwa-Young; Chae, Weon-Sik; Hong, Sam-Pyo; Park, Young-Hwan; Lee, Si Young; Choi, Je-Yong

    2017-01-01

    Silk suture material is primarily composed of silk fibroin and regarded as a non-resorbable material. It is slowly degraded by proteolysis when it is implanted into the body. 4-Hexylresorcinol (4HR) is a well-known antiseptic. In this study, the biodegradability of 4HR-incorporated silk sutures were compared to that of untreated silk sutures and polyglactin 910 sutures, a commercially available resorbable suture. 4HR-incorporated silk sutures exhibited anti-microbial properties. Matrix metalloproteinase (MMP) can digest a wide spectrum of proteins. 4HR increased MMP-2, -3, and -9 expression in RAW264.7 cells. MMP-2, -3, and -9 were able to digest not only silk fibroin but also silk sutures. Consequently, 59.5% of the 4HR-incorporated silk suture material remained at 11 weeks after grafting, which was similar to that of polyglactin 910 degradation (56.4% remained). The residual amount of bare silk suture material at 11 weeks after grafting was 91.5%. The expression levels of MMP-2, -3 and -9 were high in the 4HR-incorporated silk suture-implanted site 12 weeks after implantation. In conclusion, 4HR-treated silk sutures exhibited anti-microbial properties and a similar level of bio-degradation to polyglactin 910 sutures and induced higher expression of MMP-2, -3, and -9 in macrophages. PMID:28205580

  15. In vitro characteristics of a bioabsorbable suspension screw and suture system for endoscopic brow lift surgery.

    PubMed

    Pietrzak, William S; Eppley, Barry L

    2007-03-01

    The time requirement for endoscopic subperiosteal brow lift fixation is as little as 10-14 days. Many types of bioabsorbable fixation have been applied to this procedure, including bioabsorbable suture coupled with a bioabsorbable bone anchor, with excellent outcomes. Typically, the anchor and suture materials differ, each having their own hydrolytic strength loss profile. The dynamic relationship between the instantaneous state of degradation of the bone anchor and the suture components can affect fixation strength and failure mode, a poorly understood phenomenon. We examined the use of 2x5 mm PLLA-PGA (82:18) copolymer screws containing a suture eyelet in the head, paired with one of four types of bioabsorbable suture (2-0 and 3-0 Vicryl and 2-0 and 3-0 PDS-II), in a model system designed to mimic brow lift fixation. Constructs were inserted into a synthetic bone substrate and incubated in pH 7.4 buffer at 37 degrees C for up to 3 weeks, then loaded to failure. Initial failure loads were dependent upon suture size but not suture material, with 2-0 suture constructs (63-70N) failing at twice the load of the 3-0 suture constructs (30-35N). The following 3 week strength retentions were obtained: 40-55% for 2-0 and 3-0 Vicryl suture, 100% for 3-0 PDS-II suture, and 58% for 2-0 PDS-II suture constructs. The predominant failure mode was suture breakage at the knot, with the later intervals utilizing 2-0 PDS-II suture including some screw head failures. This suspension screw, when coupled with an appropriate suture, appears to have suitable mechanical properties for endoscopic brow lift fixation.

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

    PubMed Central

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

    2012-01-01

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

  17. One-step synthesis of silver nanoparticle-filled Nylon 6 nanofibers and their antibacterial properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel and facile one-step approach to in situ synthesize silver nanoparticle-filled nylon 6 nanofibers by electrospinning is reported. The method does not need post-treatments and can be carried out at ambient conditions without using additional chemicals. It employs the electrospinning solvent as...

  18. Swabbing for respiratory viral infections in older patients: a comparison of rayon and nylon flocked swabs.

    PubMed

    Hernes, S S; Quarsten, H; Hagen, E; Lyngroth, A L; Pripp, A H; Bjorvatn, B; Bakke, P S

    2011-02-01

    The purpose of this study was to compare the sampling efficacy of rayon swabs and nylon flocked swabs, and of oropharyngeal and nasopharyngeal specimens for the detection of respiratory viruses in elderly patients. Samples were obtained from patients 60 years of age or above who were newly admitted to Sorlandet Hospital Arendal, Norway. The patients were interviewed for current symptoms of a respiratory tract infection. Using rayon swabs and nylon flocked swabs, comparable sets of mucosal samples were harvested from the nasopharynx and the oropharynx. The samples were analysed using real-time polymerase chain reaction (PCR) methods. A total of 223 patients (mean age 74.9 years, standard deviation [SD] 9.0 years) were swabbed and a virus was recovered from 11% of the symptomatic patients. Regardless of the sampling site, a calculated 4.8 times higher viral load (95% confidence interval [CI] 1.3-17, p = 0.017) was obtained using the nylon flocked swabs as compared to the rayon swabs. Also, regardless of the type of swab, a calculated 19 times higher viral load was found in the samples from the nasopharynx as compared to the oropharynx (95% CI 5.4-67.4, p < 0.001). When swabbing for respiratory viruses in elderly patients, nasopharyngeal rather than oropharyngeal samples should be obtained. Nylon flocked swabs appear to be more efficient than rayon swabs.

  19. Comparison of Three Methods for Generating Superhydrophobic, Superoleophobic Nylon Nonwoven Surfaces (Postprint)

    DTIC Science & Technology

    2011-04-01

    present in nylon facilitate dyeing and finishing of the nonwoven fabric. We report on three chemical modification techniques as approaches for making...Taylor & Francis Books Ltd, London, p 15 23. Thompson K (2005) Ph.D. Dissertation, School of Polymer Textile & Fiber Engineering, Georgia Institute of

  20. Ultraviolet-induced irreversible tensile actuation of diacetylene/nylon microfibers

    NASA Astrophysics Data System (ADS)

    Chun, Kyoung-Yong; Choi, Changsoon; Baughman, Ray H.; Kim, Seon Jeong

    2016-07-01

    Photomechanically irreversible tensile-actuated diacetylene-embedding nylon 6/6 microfibers were investigated. 10,12-pentacosadiynoic acid (PCDA) monomer, which have conventionally provided a visual color change by temperature and photo-driven stimuli, was embedded in nylon 6/6 microfibers by wet spinning. By ultraviolet (UV) (254 nm) exposure, we observed irreversible tensile actuation (contraction) of linear (untwisted) and helical (twisted) structural microfibers. The tensile contraction of twisted nylon 6/6-PCDA microfiber containing10 mM PCDA was reached to ˜2% at 60 °C. Such irreversible tensile contraction can be promoted by volume contraction of PCDA monomers during UV exposure along with irregular structural deformation containing gauche conformation with increasing temperature. The kinetics of tensile contraction with temperature and time were shown by the Arrhenius plots. The activation energies were 34.3-35.7 kJ mol-1 as increasing the concentration of PCDA, implies that the nylon 6/6-PCDA microfibers could be applied to show time-temperature integrated device.

  1. Conductive nylon fabric through in situ synthesis of nano-silver: Preparation and characterization.

    PubMed

    Montazer, M; Komeily Nia, Z

    2015-11-01

    A simple, green and low cost method based on Tollens' reagent is presented to synthesize a nano-conductive silver layer on nylon 6 fabric. The nylon fabric was first treated with potassium permanganate to oxidize fabric surface and thereby, increasing the number of assembled particles on the fabric surface. SEM images indicated distribution of silver nanoparticles on the fabric surface and formation of nanolayer on the fiber surface. EDX and XRD patterns confirmed assembling silver nanoparticles on the nylon fibers. The treated fabrics displayed a very low electrical resistivity i.e. 4.5Ω/sq. Furthermore, the fabric color was indicated by a reflectance spectrophotometer in order to study the effects of the synthesized nanoparticles on the fabric color. It is also indicated that oxidation process has no significant influence on the mechanical properties of the fabric, and nano-treatment revenged the negative effect of oxidation of nylon fabric. Moreover, silver nanoparticles imparted reasonable antibacterial properties to the fabric against Staphylococcus aureus.

  2. Tensile testing of nylon and Kevlar parachute materials under Federal specified temperature and relative humidity conditions

    SciTech Connect

    Botner, W.T.

    1980-01-01

    A small 10-ft x 12-ft temperature and relative humidity controlled room for tensile testing of parachute materials is presented. Tensile tests of nylon and Kevlar parachute materials indicate there is a negligible change in break strength of test samples soaked in the controlled environment vs samples soaked in ambient conditions.

  3. Tensile Characterization of Injection-Molded Fuzzy Glass Fiber/Nylon Composite Material

    DTIC Science & Technology

    2016-05-01

    that the introduction of CNS increased the modulus and yield strength of the nanocomposite but reduced its fracture toughness. 15. SUBJECT TERMS...Fig. 4 SEM image of CER pellet fracture surface ...............................................4 Fig. 5 Injection-molded tensile specimens with DIC...images of test specimen fracture surface: a) neat nylon and b) 100% CER

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

    PubMed

    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.

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

    PubMed Central

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

    2013-01-01

    The skull is composed of many bones that come together at sutures. These sutures are important sites of growth, and as growth ceases some become fused while others remain patent. Their mechanical behaviour and how they interact with changing form and loadings to ensure balanced craniofacial development is still poorly understood. Early suture fusion often leads to disfiguring syndromes, thus is it imperative that we understand the function of sutures more clearly. By applying advanced engineering modelling techniques, we reveal for the first time that patent sutures generate a more widely distributed, high level of strain throughout the reptile skull. Without patent sutures, large regions of the skull are only subjected to infrequent low-level strains that could weaken the bone and result in abnormal development. Sutures are therefore not only sites of bone growth, but could also be essential for the modulation of strains necessary for normal growth and development in reptiles. PMID:23804444

  6. Multifunctional ZnO/Nylon 6 nanofiber mats by an electrospinning-electrospraying hybrid process for use in protective applications

    NASA Astrophysics Data System (ADS)

    Vitchuli, Narendiran; Shi, Quan; Nowak, Joshua; Kay, Kathryn; Caldwell, Jane M.; Breidt, Frederick; Bourham, Mohamed; McCord, Marian; Zhang, Xiangwu

    2011-10-01

    ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning-electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacteria or inhibit their growth and to catalytically detoxify chemicals. Results showed that these ZnO/Nylon 6 nanofiber mats had excellent antibacterial efficiency (99.99%) against both the Gram-negative Escherichia coli and Gram-positive Bacillus cereus bacteria. In addition, they exhibited good detoxifying efficiency (95%) against paraoxon, a simulant of highly toxic chemicals. ZnO/Nylon 6 nanofiber mats were also deposited onto nylon/cotton woven fabrics and the nanofiber mats did not significantly affect the moisture vapor transmission rates and air permeability values of the fabrics. Therefore, ZnO/Nylon 6 nanofiber mats prepared by the electrospinning-electrospraying hybrid process are promising material candidates for protective applications.

  7. In situ Polymerization of Multi-Walled Carbon Nanotube/Nylon-6 Nanocomposites and Their Electrospun Nanofibers

    NASA Astrophysics Data System (ADS)

    Saeed, Khalid; Park, Soo-Young; Haider, Sajjad; Baek, Jong-Beom

    2009-01-01

    Multiwalled carbon nanotube/nylon-6 nanocomposites (MWNT/nylon-6) were prepared by in situ polymerization, whereby functionalized MWNTs (F-MWNTs) and pristine MWNTs (P-MWNTs) were used as reinforcing materials. The F-MWNTs were functionalized by Friedel-Crafts acylation, which introduced aromatic amine (COC6H4-NH2) groups onto the side wall. Scanning electron microscopy (SEM) images obtained from the fractured surfaces of the nanocomposites showed that the F-MWNTs in the nylon-6 matrix were well dispersed as compared to those of the P-MWNTs. Both nanocomposites could be electrospun into nanofibers in which the MWNTs were embedded and oriented along the nanofiber axis, as confirmed by transmission electron microscopy. The specific strength and modulus of the MWNTs-reinforced nanofibers increased as compared to those of the neat nylon-6 nanofibers. The crystal structure of the nylon-6 in the MWNT/nylon-6 nanofibers was mostly γ-phase, although that of the MWNT/nylon-6 films, which were prepared by hot-pressing the pellets between two aluminum plates and then quenching them in icy water, was mostly α-phase, indicating that the shear force during electrospinning might favor the γ-phase, similarly to the conventional fiber spinning.

  8. In situ Polymerization of Multi-Walled Carbon Nanotube/Nylon-6 Nanocomposites and Their Electrospun Nanofibers

    PubMed Central

    2009-01-01

    Multiwalled carbon nanotube/nylon-6 nanocomposites (MWNT/nylon-6) were prepared by in situ polymerization, whereby functionalized MWNTs (F-MWNTs) and pristine MWNTs (P-MWNTs) were used as reinforcing materials. The F-MWNTs were functionalized by Friedel-Crafts acylation, which introduced aromatic amine (COC6H4-NH2) groups onto the side wall. Scanning electron microscopy (SEM) images obtained from the fractured surfaces of the nanocomposites showed that the F-MWNTs in the nylon-6 matrix were well dispersed as compared to those of the P-MWNTs. Both nanocomposites could be electrospun into nanofibers in which the MWNTs were embedded and oriented along the nanofiber axis, as confirmed by transmission electron microscopy. The specific strength and modulus of the MWNTs-reinforced nanofibers increased as compared to those of the neat nylon-6 nanofibers. The crystal structure of the nylon-6 in the MWNT/nylon-6 nanofibers was mostly γ-phase, although that of the MWNT/nylon-6 films, which were prepared by hot-pressing the pellets between two aluminum plates and then quenching them in icy water, was mostly α-phase, indicating that the shear force during electrospinning might favor the γ-phase, similarly to the conventional fiber spinning. PMID:20596470

  9. Effect of random/aligned nylon-6/MWCNT fibers on dental resin composite reinforcement.

    PubMed

    Borges, Alexandre L S; Münchow, Eliseu A; de Oliveira Souza, Ana Carolina; Yoshida, Takamitsu; Vallittu, Pekka K; Bottino, Marco C

    2015-08-01

    The aims of this study were (1) to synthesize and characterize random and aligned nanocomposite fibers of multi-walled carbon nanotubes (MWCNT)/nylon-6 and (2) to determine their reinforcing effects on the flexural strength of a dental resin composite. Nylon-6 was dissolved in hexafluoropropanol (10 wt%), followed by the addition of MWCNT (hereafter referred to as nanotubes) at two distinct concentrations (i.e., 0.5 or 1.5 wt%). Neat nylon-6 fibers (without nanotubes) were also prepared. The solutions were electrospun using parameters under low- (120 rpm) or high-speed (6000 rpm) mandrel rotation to collect random and aligned fibers, respectively. The processed fiber mats were characterized by scanning (SEM) and transmission (TEM) electron microscopies, as well as by uni-axial tensile testing. To determine the reinforcing effects on the flexural strength of a dental resin composite, bar-shaped (20×2×2 mm(3)) resin composite specimens were prepared by first placing one increment of the composite, followed by one strip of the mat, and one last increment of composite. Non-reinforced composite specimens were used as the control. The specimens were then evaluated using flexural strength testing. SEM was done on the fractured surfaces. The data were analyzed using ANOVA and the Tukey׳s test (α=5%). Nanotubes were successfully incorporated into the nylon-6 fibers. Aligned and random fibers were obtained using high- and low-speed electrospinning, respectively, where the former were significantly (p<0.001) stronger than the latter, regardless of the nanotubes׳ presence. Indeed, the dental resin composite tested was significantly reinforced when combined with nylon-6 fibrous mats composed of aligned fibers (with or without nanotubes) or random fibers incorporated with nanotubes at 0.5 wt%.

  10. Crystalline Morphology and Polymorphic Phase Transitions in Electrospun Nylon 6 Nanofibers

    PubMed Central

    Liu, Yi; Cui, Li; Guan, Fangxiao; Gao, Yi; Hedin, Nyle E.; Zhu, Lei; Fong, Hao

    2008-01-01

    Uniform nylon 6 nanofibers with diameters around 200 nm were prepared by electrospinning. Polymorphic phase transitions and crystal orientation of nylon 6 in unconfined (i.e., as-electrospun) and a high Tg (340 °C) polyimide confined nanofibers were studied. Similar to melt-spun nylon 6 fibers, electrospun nylon 6 nanofibers also exhibited predominant, meta-stable γ crystalline form, and the γ-crystal (chain) axes preferentially oriented parallel to the fiber axis. Upon annealing above 150 °C, γ-form crystals gradually melted and recrystallized into the thermodynamically stable α-form crystals, which ultimately melted at 220 °C. Release of surface tension accompanied this melt-recrystallization process, as revealed by differential scanning calorimetry. For confined nanofibers, both the melt-recrystallization and surface tension release processes were substantially depressed; γ-form crystals did not melt and recrystallize into α-form crystals until 210 °C, only 10 °C below the Tm at 220 °C. After complete melting of nano-confined crystals at 240 °C and recrystallization at 100 °C, only α-form crystals oriented perpendicular to the nanofiber axis were obtained. In the polyimide-confined nanofibers, the Brill transition (from the monoclinic α-form to a high temperature monoclinic form) was observed at 180–190 °C, which was at least 20 °C higher than that in unconfined nylon 6 at approximately 160 °C. This, again, was attributed to the confinement effect. PMID:18698379

  11. Post-coital vaginal sampling with nylon flocked swabs improves DNA typing.

    PubMed

    Benschop, Corina C G; Wiebosch, Danielle C; Kloosterman, Ate D; Sijen, Titia

    2010-02-01

    In the examination of sexual assault cases, DNA typing of vaginal samples mostly occurs after differential DNA extraction. Notwithstanding the differential extraction method, the DNA profiles from the seminal fraction often show the male alleles at low-level in combination with female alleles. This unfavorable ratio male to female DNA is due to a limited amount of sperm cells and an overwhelming quantity of female cells. In this study, we compared standard cotton and nylon flocked swabs for post-coital vaginal sampling. Twelve couples donated 88 vaginal swabs - 44 cotton, 44 nylon flocked - which were taken with a time since intercourse (TSI) up to 84 h. These vaginal swabs were sorted into categories on the basis of the TSI and submitted to (1) microscopic examination for the presence of male cells, (2) presumptive tests for the detection of seminal fluid and (3) DNA typing. Cellular elution was found to be 6-fold more efficient from the nylon flocked swabs. This makes microscopic analysis less time consuming as the higher cell yield and better cell morphology simplify detection of male cells. Both swab types reveal similar results regarding presumptive tests and male DNA typing. Positive presumptive tests (RSID-semen and PSA) were obtained up to 60 h TSI and male autosomal profiles up to 72 h TSI. Interestingly, over 50% of the samples negative for both presumptive tests resulted in informative male STR profiles. After differential extraction, less DNA was left on the nylon flocked swabs and more male DNA was isolated. Our results imply that the use of nylon flocked swabs for vaginal sampling will improve microscopic analysis and DNA typing in the medical forensic investigation of sexual assault cases.

  12. [Low colorectal anastomosis: a comparison of manual and mechanical sutures].

    PubMed

    Del Gaudio, A; Boschi, L; Petrin, C; Berardi, M; Accorsi, D

    1993-01-01

    Sixty-three carcinomas of the lower third of the rectum operated of anterior resection with low colorectal or coloanal anastomosis are presented. Handsewn anastomoses were performed in 33 patients, while staplers were used in 30 cases. The average distance of the tumor from the anal verge is 10.8 cm. in hand sutured anastomoses and 7.8 cm. in stapled ones. Dehiscences, stenosis and temporary incontinence are observed more frequently after stapled anastomosis, while the incidence of neoplastic recurrences is higher in sutured anastomosis; hospital stay and mortality are similar in the two series. Our results and literature review show that both techniques are comparable though maintaining their own specific identity and precise indication.

  13. Syneture stainless STEEL suture. A collective review of its performance in surgical wound closure.

    PubMed

    Edlich, Richard F; Drake, David B; Rodeheaver, George T; Winters, Kathryne L; Greene, Jill A; Gubler, K Dean; Long, William B; Britt, L D; Winters, Samuel P; Scott, Christine C; Lin, Kant Y

    2006-01-01

    Syneture (division of U.S. Surgical, division of Tyco Healthcare, Norwalk, Connecticut, USA) STEEL sutures are monofilament stainless steel sutures composed of 316L stainless steel conforming to ASTM Standard F138 grade 2 (" Stainless steel bar and wire for surgical implant"). STEEL sutures meet all requirements established by the United States Pharmacopeia (USP) for nonabsorbable surgical sutures. Steel sutures are for use in abdominal wound closure, intestinal anastomosis, hernia repair, sternal closure, and skin closure. They are attached to the following types of surgical needles: Roto-Grip Needles and SCC Needle. The sutures and needles are packaged in a Mylar/Tyvek outer envelope. The purposes of this clinical review are two fold. First, we will report the performance of the Syneture STEEL suture product in the largest studies of suture performance ever reported in the literature. In addition, we will provide comprehensive information from the surgical literature that highlights the unique benefits of stainless steel sutures for the following wound closure techniques: sternal fixation, abdominal wound repair, inguinal hernia repair, and skin wound closure. Consorta Inc. (Rolling Meadows, Illinois), a leading healthcare resource management group purchasing organization, and Syneture, jointly with a clinician task force, designed a reproducible surgical evaluation program for needles and sutures in a large cooperative of healthcare systems. Because of the subjective nature of the more commonly used suture selection techniques, a nonexperimental observational study approach was designed to replace perception of performance characteristics with actual clinical experience. In a report involving 19 Consorta shareholder hospitals, they discussed the preliminary part (Phase I) of a large nonexperimental observational study of the clinical performance of surgical needles and sutures. Performance characteristics of the sutures and needles produced by Syneture that were

  14. Strength Evaluation and Failure Prediction of Short Carbon Fiber Reinforced Nylon Spur Gears by Finite Element Modeling

    NASA Astrophysics Data System (ADS)

    Hu, Zhong; Hossan, Mohammad Robiul

    2013-06-01

    In this paper, short carbon fiber reinforced nylon spur gear pairs, and steel and unreinforced nylon spur gear pairs have been selected for study and comparison. A 3D finite element model was developed to simulate the multi-axial stress-strain behaviors of the gear tooth. Failure prediction has been conducted based on the different failure criteria, including Tsai-Wu criterion. The tooth roots, where has stress concentration and the potential for failure, have been carefully investigated. The modeling results show that the short carbon fiber reinforced nylon gear fabricated by properly controlled injection molding processes can provide higher strength and better performance.

  15. The south Zagros suture zone in teleseismic images

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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 (p<0.05). There was significantly less pain, swelling and trismus at 24 h and 48 h, respectively, in the suture-less group (p<0.05). There was no significant difference between the two treatment groups in terms of pain, swelling and trismus, at 1 week postoperatively (p>0.05). There is less postoperative pain, swelling and trismus with the suture-less technique in third molar surgery.

  17. Fabrication and feasibility study of an absorbable diacetyl chitin surgical suture for wound healing.

    PubMed

    Shao, Kai; Han, Baoqin; Gao, Jinning; Jiang, Zhiwen; Liu, Weizhi; Liu, Wanshun; Liang, Ye

    2016-01-01

    Diacetyl chitin (DAC) is an acidylated chitin obtained using acetic anhydride mixed perchloric acid system. By wet spinning and weaving technique, DAC has been successfully developed into a novel absorbable surgical suture. Thanks to the unique properties of chitins, the potential application of this novel monocomponent multifilament DAC suture may break the monopoly of synthetic polymer sutures in wound closure area. In this study, DAC was synthesized and characterized by multiple approaches including elemental analysis, Fourier transform infrared spectrometry (FTIR), and X-ray diffraction (XRD). In addition, we performed the feasibility assessment of DAC suture (USP 2-0) as absorbable suture for wound healing. Several lines of evidences suggested that DAC suture had comparable mechanical properties as synthetic polymer sutures. Moreover, DAC suture retained approximately 63% of the original strength at 14 days and completely absorbed in 42 days with no remarkable tissue reaction in vivo. Most important of all, DAC suture significantly promoted skin regeneration with faster tissue reconstruction and higher wound breaking strength on a linear incisional wound model. All these results demonstrated the potential use of DAC suture in short- or middle-term wound healing, such as epithelial and connective tissue.

  18. Bending and abrasion fatigue of common suture materials used in arthroscopic and open orthopedic surgery.

    PubMed

    Savage, Earle; Hurren, Christopher J; Slader, Simon; Khan, Lukman A K; Sutti, Alessandra; Page, Richard S

    2013-01-01

    In orthopedic surgery, the reattachment of tendon to bone requires suture materials that have stable and durable properties to allow time for healing at the tendon-bone interface. The suture, not rigidly restrained within the anchor eyelet, is free to move during surgery and potentially after surgery with limb motion. During such movement, the suture is subjected to bending and frictional forces that can lead to fatigue-induced failure. We investigated some common contemporary commercial number-two-grade suture materials and evaluated their resistance to bending abrasion fatigue and the consequent failure. Sutures were oscillated over a stainless steel wire at low frequency under load. Number of abrasion cycles to failure, changes in suture morphology, and fatigue-failure method was recorded for each material. Suture structure had a significant effect on abrasion resistance, with braided sutures containing large numbers of fine high tenacity core filaments performing 15-20 times better than other braided suture structures. Ultra high molecular weight polyethylene (UHMWPE) core filaments resisted bending abrasion failure better than other core materials due to the load spreading and abrasion resistance of these filaments. Sutures with UHMWPE cores also had high resistance to tensile failure. Limited correlation was observed between tensile strength and abrasion resistance.

  19. Bundles of Spider Silk, Braided into Sutures, Resist Basic Cyclic Tests: Potential Use for Flexor Tendon Repair

    PubMed Central

    Hennecke, Kathleen; Redeker, Joern; Kuhbier, Joern W.; Strauss, Sarah; Allmeling, Christina; Kasper, Cornelia; Reimers, Kerstin; Vogt, Peter M.

    2013-01-01

    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. PMID:23613793

  20. Mechanical reinforcement and environmental effects on a nylon-6/clay nanocomposite

    NASA Astrophysics Data System (ADS)

    Shelley, J. Stebbins

    2000-10-01

    Hybridization, or modifying the organic polymers with inorganic constituents, is one method of achieving mechanical property improvements in polymeric materials while preserving processing characteristics. Toyota Central Research developed, and Ube Industries commercialized, one such hybrid nanocomposite: nylon-6/montmorillonite clay. This dissertation explores mechanisms of reinforcement in these nylon-6/clay nanocomposites and studies their degradation by atmospheric pollutants. A 100% improvement in modulus, 77% improvement in yield stress, and 54°C improvement in heat distortion temperature over nylon-6 were observed in extruded 5 wt% clay nanocomposite sheets. Infrared absorption spectrography and dynamic mechanical analysis were used to investigate the mechanisms of reinforcement in these nanocomposites. The improved mechanical properties, increased heat distortion temperature, reduced diffusion rate, and lower susceptibility to degradation in NO x observed where attributed to constraint of polymer chain motion by interaction with clay lamellae. Changes in the loss tangent peak in the glass transition region of the dynamic mechanical data provide an estimate of the volume of chains constrained by complexation of their mid-chain amide oxygen groups with the charged clay lamellae. X-ray analysis, optical microscopy, and light scattering were used to study changes in crystallization due to this complexation. Photomicrographs indicate that the morphology of the crystallites change from spherulitic to planar with the addition of clay. Decreases in diffusion rates of water and total water absorption were demonstrated in immersion experiments. Complexation of nylon-6 with 5 wt% clay reduces the total absorption of water by over 16%. The plane stress fracture toughness of extruded 5 wt% clay nanocomposite was 46% greater than that of nylon-6. The degradation of the nanocomposites in calcium chloride solution and NOx was examined through post exposure residual

  1. Evaluation of Cross-contamination of Nylon Bags with Heavy-loaded Gasoline Fire Debris and with Automotive Paint Thinner.

    PubMed

    Belchior, Filipa; Andrews, Stephen P

    2016-11-01

    Nylon bags are used for packaging fire debris in several countries, particularly in Europe. The possibility of cross-contamination during transport from the fire scene to the laboratory, in normal casework conditions in the U.K., was studied for two brands of nylon bags, using simulated heavy-loaded fire debris. Three experiments were carried out with each brand, using as sample a piece of cotton fabric soaked with gasoline. One experiment was carried out using automotive paint thinner (oxygenated solvent). Each sample was sealed in a nylon bag and stored in contact with eight empty bags. The empty bags were analysed at regular intervals for a period of time up to 8 weeks, using SPME and GC/MS. Cross-contamination was found for components of gasoline (toluene and C2 -alkylbenzenes) in the two brands of nylon bags used, after 4 days and 2 weeks. Cross-contamination using automotive topcoat thinner was detected after 2 days.

  2. Isolation and recovery of cellulose from waste nylon/cotton blended fabrics by 1-allyl-3-methylimidazolium chloride.

    PubMed

    Lv, Fangbing; Wang, Chaoxia; Zhu, Ping; Zhang, Chuanjie

    2015-06-05

    Development of a simple process for separating cellulose and nylon 6 from their blended fabrics is indispensable for recycling of waste mixed fabrics. An efficient procedure of dissolution of the fabrics in an ionic liquid 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and subsequent filtration separation has been demonstrated. Effects of treatment temperature, time and waste fabrics ratio on the recovery rates were investigated. SEM images showed that the cotton cellulose dissolved in [AMIM]Cl while the nylon 6 fibers remained. The FTIR spectrum of regenerated cellulose (RC) was similar with that of virgin cotton fibers, which verified that no other chemical reaction occurred besides breakage of hydrogen bonds during the processes of dissolution and separation. TGA curves indicated that the regenerated cellulose possessed a reduced thermal stability and was effectively removed from waste nylon/cotton blended fabrics (WNCFs). WNCFs were sufficiently reclaimed with high recovery rate of both regenerated cellulose films and nylon 6 fibers.

  3. Layer-by-Layer Assembly of Halogen-Free Polymeric Materials on Nylon/Cotton Blend for Flame Retardant Applications

    DTIC Science & Technology

    2015-07-01

    safe, halogen free, anionic sodium phosphate and cationic polysiloxanes were deposited on a Nyco (1:1 nylon/cotton blend) fabric via layer-by-layer... sodium phosphate and cationic polysiloxanes were deposited on a Nyco (1:1 nylon/cotton blend) fabric via layer-by-layer (LbL) assembly to reduce the...used are poly(allylamine), poly(acryl amide), poly(acrylic acid), inorganic materials such as montmorillonite, ammonium polyphosphate and poly( sodium

  4. The combination of a nylon and traditional partial removable dental prosthesis for improved esthetics: a clinical report.

    PubMed

    Ito, Masayasu; Wee, Alvin G; Miyamoto, Takanari; Kawai, Yasuhiko

    2013-01-01

    A benefit of a nylon partial removable dental prosthesis (PRDP) is the absence of a metal framework, providing improved esthetics. Unfortunately, the lack of a traditional framework reduces rigidity and the support of occlusal rests. This clinical report describes a combination of a nylon PRDP (polyamide denture base resin) and a traditional PRDP (framework/resin) for a Kennedy Class II, Modification 1, partially edentulous mandible.

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

    SciTech Connect

    Toth, Sandor; Legradi, Gabor; Aszodi, Attila

    2006-07-01

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

  6. Structural Asymmetry-Facilitated Tunability of Spin Distribution in the (10, 0) Carbon Nanotube Induced by Charging

    NASA Astrophysics Data System (ADS)

    Wang, Jia; Gao, Yang; Zhang, Zhiyuan; Xu, Dexuan; Wang, Zhigang; Zhang, Rui-Qin

    2017-01-01

    Constructing the asymmetric electronic structure of low-dimensional carbon nanomaterials is significant for application of molecular devices, such as magnetic switches. In this work, we use density functional theory to investigate the asymmetric spin distribution in a typical (10, 0) carbon nanotube by capping one end with a fullerene hemisphere and saturating the dangling bonds with hydrogen atoms at the other end. Calculated results indicate that this geometry obviously modified the distribution of spin density along the tube axis, and the electrons present were antiferromagnetically coupled at both ends. Specifically, the change in magnetic order at the end of the cap can be changed with either the increase or decrease of the charge. In addition, the analysis of electron density difference shows that charge induces gain or loss of electrons not only at the open end, but also at the cap end. These findings provide a strategy for controlling spin distribution for nanoscale functional molecular devices through a simple charge adjustment.

  7. Orientation of late Precambrian sutures in the Arabian-Nubian shield

    NASA Astrophysics Data System (ADS)

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

    1990-11-01

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

  8. [Developments in suture techniques of hand flexor tendon injuries during the last fifteen years].

    PubMed

    Bíró, Vilmos

    2016-02-07

    In the reconstruction of hand flexor tendon injuries it is fundamental to select the best suture technique, which makes possible early, active postoperative mobilization and achievement of the best results. The author reviews the development of suture techniques of the flexor tendon injuries during the last fifteen years, and discusses experimental tendon reconstruction results as well as clinical outcomes. The author describes the importance of different tendon suture materials, the significance of the pulley system of the fingers, the stretching between the sutured tendon ends by tendon sutures and, finally, the importance of the moving course in the reconstructed tendon. He states, that the wide-range adoption of the discussed modern tendon sutures would be necessary for better postoperative results.

  9. Orientation of late Precambrian sutures in the Arabian-Nubian shield

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  10. Utility of the frontonasal suture for estimating age at death in human skeletal remains.

    PubMed

    Alesbury, Helen S; Ubelaker, Douglas H; Bernstein, Robin

    2013-01-01

    This project evaluated the utility of the frontonasal suture for estimating age at death. Utilizing human remains of known age at death with varying degrees of fusion, curated at the American Museum of Natural History in New York City and the Smithsonian Institution's National Museum of Natural History in Washington, DC, data were collected from the ectocranial surface of 522 crania; 68 of these were sagittally sectioned, allowing collection of internal data and observation of suture closure through the bone. Degree of ectocranial suture closure does not significantly predict age, even when sex and ancestry are accounted for. Suture closure progression data were converted into a Hershkovitz ratio (sum of the measurement of open portion divided by the total suture length), and regression models demonstrate that the effect of age accounts for only 13% of variation in suture closure.

  11. [Effect of abrasion on three types of sutures in a metallic anchor].

    PubMed

    Acosta Rodríguez, Eduardo; Almazán Díaz, Arturo

    2007-01-01

    It is necessary to slide the suture into the articulation in the arthroscopic techniques, this produce friction and abrasion of the suture, this is the principal cause of failure in the union of anchor-suture. We used a Fastak 2.4 anchor, Sawbones, No 2 Ethibond, No 2 Fiberwire and No 2 Herculine. Each suture was introduce to the anchor eyelet and was cycled in four times with 40N. The angles of traction were 0 degrees and 45 degrees at the same direction of the anchor eyelet and 45 degrees with different direction of the anchor eyelet. Five sutures were used in every test. We performed the Kolmogorov-Smirnof and "t" Student tests. In all the tests there were a significant differences. The strength of the suture is affected by the abrasion in the anchor eyelet.

  12. Chemisorption of estrone in nylon microfiltration membranes: Adsorption mechanism and potential use for estrone removal from water.

    PubMed

    Han, Jie; Qiu, Wei; Hu, Jiangyong; Gao, Wei

    2012-03-01

    Estrone is a representative steroid estrogen contaminant that has been detected in effluents from sewage treatment facilities, as well as in surface and ground waters. Our study shows that estrone can be readily removed from water via a unique chemisorption mechanism using nylon microfiltration membranes. Experiments on a laboratory in-line filtration system showed instant removal of estrone from 200 μg/l aqueous solutions by 0.45-μm nylon membranes (ca. 35 L per m(2) membrane). Comparisons with 0.45-μm PVDF, PTFE and glass microfiber membranes suggested that the significant estrone adsorption in nylon membrane should be predominately driven by a different mechanism rather than common physical adsorption. Fourier transform infrared spectroscopy study on nylon membranes and a model compound, N-methylacetamide, showed that the significant adsorption originated from the hydrogen bonding between terminal -OH groups on estrone molecules and nucleophile -C=O groups in amide groups of nylon 6,6. The saturated nylon membrane showed very low leachability in ambient water, while it could be effectively regenerated in alkaline or ethanol solutions. Preliminary reusability study showed that the membrane maintained a consistent adsorption capacity for estrone during ten cycles of reuse. The chemisorption-based polymeric adsorption may provide a new alternative approach for removing estrone and potentially other trace organic contaminants from water.

  13. Characterization of the Circumlimbal Suture Model of Chronic IOP Elevation in Mice and Assessment of Changes in Gene Expression of Stretch Sensitive Channels

    PubMed Central

    Zhao, Da; Nguyen, Christine T. O.; Wong, Vickie H. Y.; Lim, Jeremiah K. H.; He, Zheng; Jobling, Andrew I.; Fletcher, Erica L.; Chinnery, Holly R.; Vingrys, Algis J.; Bui, Bang V.

    2017-01-01

    To consider whether a circumlimbal suture can be used to chronically elevate intraocular pressure (IOP) in mice and to assess its effect on retinal structure, function and gene expression of stretch sensitive channels. Anesthetized adult C57BL6/J mice had a circumlimbal suture (10/0) applied around the equator of one eye. In treated eyes (n = 23) the suture was left in place for 12 weeks whilst in sham control eyes the suture was removed at day two (n = 17). Contralateral eyes served as untreated controls. IOP was measured after surgery and once a week thereafter. After 12 weeks, electroretinography (ERG) was performed to assess photoreceptor, bipolar cell and retinal ganglion cell (RGC) function. Retinal structure was evaluated using optical coherence tomography. Retinae were processed for counts of ganglion cell density or for quantitative RT-PCR to quantify purinergic (P2x7, Adora3, Entpd1) or stretch sensitive channel (Panx1, Trpv4) gene expression. Immediately after suture application, IOP spiked to 33 ± 3 mmHg. After 1 day, IOP had recovered to 27 ± 3 mmHg. Between weeks 2 and 12, IOP remained elevated above baseline (control 14 ± 1 mmHg, ocular hypertensive 19 ± 1 mmHg). Suture removal at day 2 (Sham) restored IOP to baseline levels, where it remained through to week 12. ERG analysis showed that 12 weeks of IOP elevation reduced photoreceptor (−15 ± 4%), bipolar cell (−15 ± 4%) and ganglion cell responses (−19 ± 6%) compared to sham controls and respective contralateral eyes (untreated). The retinal nerve fiber layer was thinned in the presence of normal total retinal thickness. Ganglion cell density was reduced across all quadrants (superior −12 ± 5%; temporal, −7% ± 2%; inferior −9 ± 4%; nasal −8 ± 5%). Quantitative RT-PCR revealed a significant increase in Entpd1 gene expression (+11 ± 4%), whilst other genes were not significantly altered (P2x7, Adora3, Trpv4, Panx1). Our results show that circumlimbal ligation produces mild

  14. Evaluation of anaerobic degradation, biogas and digestate production of cereal silages using nylon-bags.

    PubMed

    Negri, Marco; Bacenetti, Jacopo; Fiala, Marco; Bocchi, Stefano

    2016-06-01

    In this study, the degradation efficiency and the biogas and digestate production during anaerobic digestion were evaluated for the cereal silages most used to feed biogas plants. To this purpose, silages of: maize from the whole plant, maize from the ear, triticale and wheat were digested, inside of nylon bags, in laboratory scale digesters, for 75days. Overall, the test involved 288 nylon bags. After 75days of digestion, the maize ear silage shows the highest degradation efficiency (about 98%) while wheat silage the lowest (about 83%). The biogas production ranges from 438 to 852Nm(3)/t of dry matter for wheat and ear maize silage, respectively. For all the cereal silages, the degradation as well as the biogas production are faster at the beginning of the digestion time. Digestate mass, expressed as percentage of the fresh matter, ranges from 38% to 84% for wheat and maize ear silage, respectively.

  15. Effect of antiarrhythmic drugs on In-111-labeled leukocytes: chemotaxis and adherence to nylon wool

    SciTech Connect

    Thakur, M.L.; Walsh, L.J.; Zaret, B.L.; Gottschalk, A.

    1982-02-01

    The influence of lidocaine (L) and procainamide (P) on the chemotactic ability and adherence to nylon wool of In-111-labeled human polymorphonuclear leukocytes (PMNs) was investigated. At the normal therapeutic levels of L (0.022 mM whole blood) or P (0.03 mM whole blood) no change in PMN function was observed. However, at and above five times the aforementioned blood levels of L, significant reduction in the chemotactic ability of PMNs was noted (p less than 0.005). The adverse effects of In-111 radiation appeared insignificant at all L or P concentrations during the 3-hr observation period. The labeled PMNs were resistant to the toxic effects of a higher concentration of P than that of L, and the reduction in PMN chemotaxis and adherence to nylon wool was not apparent until the P concentration reached 1.5 mM.

  16. Effect of antiarrhythmic drugs on In-111-labeled leukocytes: chemotaxis and adherence to nylon wool

    SciTech Connect

    Thakur, M.L.; Walsh, L.J.; Zaret, B.L.; Gottschalk, A.

    1982-02-01

    The influence of lidocaine (L) and procainamide (P) on the chemotactic ability and adherence to nylon wool of In-111-labeled human polymorphonuclear leukocytes (PMNs) was investigated. At the normal therapeutic levels of L (0.022 mM whole blood) or P (0.03 mM whole blood) no change in PMN function was observed. However, at and above five times the aforementioned blood levels of L, significant reduction in the chemotactic ability of PMNs was noted (P <0.005). The adverse effects of In-111 radiation appeared insignificant at all L or P concentrations during the 3-hr observation period. The labeled PMNs were resistant to the toxic effects of a higher concentration of P than that of L, and the reduction in PMN chemotaxis and adherence to nylon wool was not apparent until the P concentration reached 1.5 mM.

  17. Layered conductive polymer on nylon membrane templates for high performance, thin-film supercapacitor electrodes

    NASA Astrophysics Data System (ADS)

    Shi, HaoTian Harvey; Naguib, Hani E.

    2016-04-01

    Flexible Thin-film Electrochemical Capacitors (ECs) are emerging technology that plays an important role as energy supply for various electronics system for both present era and the future. Intrinsically conductive polymers (ICPs) are promising pseudo-capacitive materials as they feature both good electrical conductivity and high specific capacitance. This study focuses on the construction and characterization of ultra-high surface area porous electrodes based on coating of nano-sized conductive polymer materials on nylon membrane templates. Herein, a novel nano-engineered electrode material based on nylon membranes was presented, which allows the creation of super-capacitor devices that is capable of delivering competitive performance, while maintaining desirable mechanical characteristics. With the formation of a highly conductive network with the polyaniline nano-layer, the electrical conductivity was also increased dramatically to facilitate the charge transfer process. Cyclic voltammetry and specific capacitance results showed promising application of this type of composite materials for future smart textile applications.

  18. Alternative fatty food simulants and diffusion kinetics of nylon 12 food packaging.

    PubMed

    Stoffers, N H; Dekker, M; Linssen, J P H; Störmer, A; Franz, R

    2003-10-01

    The migration of laurolactam and cyclic di- and trimer of nylon 12 was assessed using three different films and five food simulants (olive oil, isooctane, 95% ethanol, 50% ethanol, water). Substitute test conditions for migration into olive oil according to European Union Directive EC/97/48 were applied using 95% ethanol and isooctane. Results showed that 95% ethanol overestimated while isooctane underestimated the respective migration into olive oil. Water was the best olive oil substitute, as migration of laurolactam into water and olive oil using the same temperature gave similar results. Additionally, diffusion kinetics of laurolactam were investigated by migration kinetic studies using isooctane and olive oil. Diffusion coefficients determined with isooctane were significantly higher than those found using olive oil. It was proved that isooctane had an interaction and olive oil was inert to the polymer. The diffusion conductance parameter, A(p), for nylon 12 determined using olive oil ranged from 0.3 to 0.6.

  19. Enhancement of strength and stiffness of Nylon 6 filaments through carbon nanotubes reinforcement

    NASA Astrophysics Data System (ADS)

    Mahfuz, Hassan; Adnan, Ashfaq; Rangari, Vijay K.; Hasan, Mohammad M.; Jeelani, Shaik; Wright, Wendelin J.; DeTeresa, Steven J.

    2006-02-01

    We report a method to fabricate carbon nanotube reinforced Nylon filaments through an extrusion process. In this process, Nylon 6 and multiwalled carbon nanotubes (MWCNT) are first dry mixed and then extruded in the form of continuous filaments by a single screw extrusion method. Thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC) studies have indicated that there is a moderate increase in Tg without a discernible shift in the melting endotherm. Tensile tests on single filaments have demonstrated that Young's modulus and strength of the nanophased filaments have increased by 220% and 164%, respectively with the addition of only 1wt.% MWCNTs. SEM studies and micromechanics based calculations have shown that the alignment of MWCNTs in the filaments, and high interfacial shear strength between the matrix and the nanotube reinforcement was responsible for such a dramatic improvement in properties.

  20. Sequential lift and suture technique for post-LASIK corneal striae.

    PubMed

    Mackool, Richard J; Monsanto, Vivian R

    2003-04-01

    We describe a surgical technique to manage persistent corneal striae after laser in situ keratomileusis (LASIK). The sequential lift and suture technique reduces the time required for LASIK, eliminates the need to fixate the flap with forceps during suturing, and increases the accuracy of suture placement. The results in 10 eyes (9 patients) showed complete resolution of striae with improvement in subjective symptoms (glare and blurred vision) and best corrected visual acuity.

  1. Quantitative physical and handling characteristics of novel antibacterial braided silk suture materials.

    PubMed

    Chen, Xiaojie; Hou, Dandan; Tang, Xiaoqi; Wang, Lu

    2015-10-01

    Surgical braided silk sutures have been widely used because these materials exhibit good handling characteristics, ease of use, and ideal knot security. However, surgical silk sutures likely cause surgical site infections because these sutures are composed of natural protein materials with a braided structure. As such, antibacterial silk sutures for clinical wound closure should be developed. Braided silk suture could be treated and modified with antibacterial agent, provided that excellent physical and handling characteristics of this material should maximize maintained. This study aimed to quantitatively investigate the effect of antibacterial treatment with different parameters on physical and handling characteristics of novel antibacterial braided silk sutures. Physical and handling characteristics, including appearance, knot-pull tensile strength, pullout friction resistance, tissue drag friction resistance, and bending stiffness, were evaluated. After physical and handling tests were conducted, images showed morphological characteristics were obtained and evaluated to investigate the relationship between antibacterial treatment and physical and handling properties. Results showed that suture diameter increased and reached the nearest thick size specification; knot-pull tensile strength decreased but remained higher than the standard value by at least 40.73%. Fracture asynchronism during knot-pull tensile strength test suggested that the fineness ratio of shell and core strands may enhance knot-pull tensile strength. Static and dynamic frictions of suture-to-suture friction behavior were slightly affected by antibacterial treatment, and changed to less than 16.07% and 32.77%, respectively. Suture-to-tissue friction and bending stiffness increased by approximately 50%; the bending stiffness of the proposed suture remained efficient compared with that of synthetic sutures. Therefore, good physical and handling characteristics can be maintained by selecting

  2. [An improved single-layer suture in the surgery of small and large intestines].

    PubMed

    Kapustin, B B; Sysoev, S V

    2010-01-01

    The methods and results of using single-layer interrupted intestinal suture in operations on the small and large intestines are presented. Using the suture decreases the number of complications associated with this technique, improves the direct results of operations and reduces postoperative lethality both in urgent and planned surgery. The proposed intestinal suture is thought to be justified in connecting similar and dissimilar parts of the intestinal tube in the variants of longitudinal, transversal, terminal, lateral and termino-lateral interintestinal anastomoses.

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

    PubMed

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

    1990-10-01

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

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

    PubMed

    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.

  5. Laser-optical treatment for toothbrush bristles (nylon, synthetic, and polymeric materials, etc.)

    NASA Astrophysics Data System (ADS)

    Ma, Yangwu

    1994-08-01

    On the basis of the principle of laser radiation and materials interaction, a laser-optical treatment method for toothbrush bristles (nylon et al., synthetic and polymeric materials) is provided. In this process, laser irradiation is stopped during melting and followed by cooling, so the free end of each bristle of toothbrush is formed for a smooth globe. The toothbrush with laser-optical end-globed bristles have many remarkable functions.

  6. Supersonically blown nylon-6 nanofibers entangled with graphene flakes for water purification

    NASA Astrophysics Data System (ADS)

    Lee, Jong-Gun; Kim, Do-Yeon; Mali, Mukund G.; Al-Deyab, Salem S.; Swihart, Mark T.; Yoon, Sam S.

    2015-11-01

    Water purification membranes, capable of purifying a few to tens of milliliters of aqueous methylene blue solution in a minute, were produced by supersonically blowing graphene flakes with a nylon-6 polymeric solution. The solution-blown nylon-6 nanofibers became entangled with graphene flakes thereby locking the graphene flakes within the frame of the bendable two-dimensional film structure. This method, which yielded a 5 × 7 cm2-sized membrane in less than 10 seconds, is commercially viable owing to fast fabrication and scalability. We show that our water purification device allows a flow rate range of 0.3-4 L h-1 with a membrane area of just 5 cm2, under a pressure difference of 0.5-3.5 bar. If the membrane were scaled up to 0.5 m2, it could provide 300-4000 L h-1 flow rate, an ample supply for home use.Water purification membranes, capable of purifying a few to tens of milliliters of aqueous methylene blue solution in a minute, were produced by supersonically blowing graphene flakes with a nylon-6 polymeric solution. The solution-blown nylon-6 nanofibers became entangled with graphene flakes thereby locking the graphene flakes within the frame of the bendable two-dimensional film structure. This method, which yielded a 5 × 7 cm2-sized membrane in less than 10 seconds, is commercially viable owing to fast fabrication and scalability. We show that our water purification device allows a flow rate range of 0.3-4 L h-1 with a membrane area of just 5 cm2, under a pressure difference of 0.5-3.5 bar. If the membrane were scaled up to 0.5 m2, it could provide 300-4000 L h-1 flow rate, an ample supply for home use. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06549f

  7. Screening nylon-3 polymers, a new class of cationic amphiphiles, for siRNA delivery.

    PubMed

    Nadithe, Venkatareddy; Liu, Runhui; Killinger, Bryan A; Movassaghian, Sara; Kim, Na Hyung; Moszczynska, Anna B; Masters, Kristyn S; Gellman, Samuel H; Merkel, Olivia M

    2015-02-02

    Amphiphilic nucleic acid carriers have attracted strong interest. Three groups of nylon-3 copolymers (poly-β-peptides) possessing different cationic/hydrophobic content were evaluated as siRNA delivery agents in this study. Their ability to condense siRNA was determined in SYBR Gold assays. Their cytotoxicity was tested by MTT assays, their efficiency of delivering Alexa Fluor-488-labeled siRNA intracellularly in the presence and absence of uptake inhibitors was assessed by flow cytometry, and their transfection efficacies were studied by luciferase knockdown in a cell line stably expressing luciferase (H1299/Luc). Endosomal release was determined by confocal laser scanning microscopy and colocalization with lysotracker. All polymers efficiently condensed siRNA at nitrogen-to-phosphate (N/P) ratios of 5 or lower, as reflected in hydrodynamic diameters smaller than that at N/P 1. Although several formulations had negative zeta potentials at N/P 1, G2C and G2D polyplexes yielded >80% uptake in H1299/Luc cells, as determined by flow cytometry. Luciferase knockdown (20-65%) was observed after transfection with polyplexes made of the high molecular weight polymers that were the most hydrophobic. The ability of nylon-3 polymers to deliver siRNA intracellularly even at negative zeta potential implies that they mediate transport across cell membranes based on their amphiphilicity. The cellular uptake route was determined to strongly depend on the presence of cholesterol in the cell membrane. These polymers are, therefore, very promising for siRNA delivery at reduced surface charge and toxicity. Our study identified nylon-3 formulations at low N/P ratios for effective gene knockdown, indicating that nylon-3 polymers are a new, promising type of gene delivery agent.

  8. An accessory skull suture mimicking a skull fracture.

    PubMed

    Wiedijk, J E F; Soerdjbalie-Maikoe, V; Maat, G J R; Maes, A; van Rijn, R R; de Boer, H H

    2016-03-01

    This paper describes an investigation of the sudden and unexpected death of a five-and-a-half-month-old boy. As in every Dutch case of sudden unexpected death in infancy (SUDI), a multidisciplinary diagnostic approach was used. This included post-mortem radiography, showing a linear discontinuity of the parietal bone. Originally this was interpreted as a skull fracture, but autopsy indicated no signs of mechanical trauma. Instead the defect was defined as a unilateral accessory suture of the parietal bone. The initial erroneous diagnosis had severe adverse consequences and thus every health care professional or forensic specialist dealing with paediatric mechanical traumas should be cautious of this rare anomaly.

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

    PubMed

    Tsao, Sean W; Holz, Huck A

    2015-03-01

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

  10. Effectivity of intraoperative adjustable suture technique in horizontal strabismus

    PubMed Central

    Altintas, Ayse Gul Kocak; Arifoglu, Hasan Basri; Midillioglu, Inci Kocak; Gungor, Elif Damar; Simsek, Saban

    2013-01-01

    AIM To compare the long-term effectivity of intraoperative adjustable suture technique with traditional non-adjustable strabismus surgery. METHODS Two hundred and thirty-three patients, who underwent strabismus surgery either with traditional procedures or one-stage intraoperative adjustable suture technique, were included in our long-term follow-up study. One hundred and eighteen patients were evaluated in traditional surgery group (TSG) and 115 who underwent adjustable suture were in the one-stage intraoperative adjustable surgery group (ASG). In this group 9 patients had paralytic strabismus and 16 had reoperations, 2 patients had restrictive strabismus related to thyroid eye disease. The mean follow up in the TSG was 26.2 months and it was 24.8 months in the ASG group. RESULTS In patients with exotropia (XT) the mean correction of deviation for near fixation in ASG (32.4±13.2PD) and in TSG (26.4±8.2PD) were similar (P=0.112). The correction for distant fixation in ASG (33.2±11.4PD) and TSG (30.9±7.2PD) were not significantly different (P=0.321). In patients with esotropia (ET) even the mean correction of deviation for both near (31±12PD) and distant (30.6±12.8PD) fixations were higher in ASG than in TSG, for both near (28.27±14.2PD) and distant (28.9±12.9PD) fixations, the differences were not significant (P=0.346, 0.824 respectively). The overall success rate of XT patient was 78.9% in TSG and 78.78% in ASG, the difference was not significant (P=0.629). The success rates were 78.75% in TSG and 75.51% in ASG in ET patient, which was also not significantly different (P=0.821). CONCLUSION Although patients in ASG had more complex deviation such as paralysis, reoperations and restrictive strabismus, success rates of this tecnique was as high as TSG which did not contain complicated deviation. One-stage intraoperative adjustable suture technique is a safe and effective method for cooperative patient who has complex deviation. PMID:23991385

  11. Patterns and implications of extensive heterochrony in carnivoran cranial suture closure

    PubMed Central

    Goswami, A; Foley, L; Weisbecker, V

    2013-01-01

    Heterochronic changes in the rate or timing of development underpin many evolutionary transformations. In particular, the onset and rate of bone development have been the focus of many studies across large clades. In contrast, the termination of bone growth, as estimated by suture closure, has been studied far less frequently, although a few recent studies have shown this to represent a variable, although poorly understood, aspect of developmental evolution. Here, we examine suture closure patterns across 25 species of carnivoran mammals, ranging from social-insectivores to hypercarnivores, to assess variation in suture closure across taxa, identify heterochronic shifts in a phylogenetic framework and elucidate the relationship between suture closure timing and ecology. Our results show that heterochronic shifts in suture closure are widespread across Carnivora, with several shifts identified for most major clades. Carnivorans differ from patterns identified for other mammalian clades in showing high variability of palatal suture closure, no correlation between size and level of suture closure, and little phylogenetic signal outside of musteloids. Results further suggest a strong influence of feeding ecology on suture closure pattern. Most of the species with high numbers of heterochronic shifts, such as the walrus and the aardwolf, feed on invertebrates, and these taxa also showed high frequency of closure of the mandibular symphysis, a state that is relatively rare among mammals. Overall, caniforms displayed more heterochronic shifts than feliforms, suggesting that evolutionary changes in suture closure may reflect the lower diversity of cranial morphology in feliforms. PMID:23530892

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

    PubMed

    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.

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

    PubMed

    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.

  14. Continuous electrospinning of polymer nanofibers of Nylon-6 using an atomic force microscope tip.

    PubMed

    Gururajan, Giriprasath; Sullivan, S P; Beebe, T P; Chase, D B; Rabolt, J F

    2011-08-01

    An atomic force microscopy (AFM) probe is successfully utilized as an electrospinning tip for fabricating Nylon-6 nanofibers. The nanometre-size tip enabled controlled deposition of uniform polymeric nanofibers within a 1 cm diameter area. Nylon-6 nanofibers were continuously electrospun at a solution concentration as low as 1 wt% Nylon-6 in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). Wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) results of the AFM electrospun fibers indicated that the nanofibers predominantly display the meta-stable γ crystalline form suggesting rapid crystallization rate during the process. In addition to precise control over fiber deposition and diameter, some of the drawbacks of conventional electrospinning such as large volume of solutions and clogging of needles can be overcome using this AFM based electrospinning technique. Lastly, a comparison of electrospun fibers from syringe-needle based electrospinning and AFM probe-tip based electrospinning indicated significant morphological and microstructural differences in the case of AFM based electrospinning.

  15. Continuous electrospinning of polymer nanofibers of Nylon-6 using an atomic force microscope tip

    NASA Astrophysics Data System (ADS)

    Gururajan, Giriprasath; Sullivan, S. P.; Beebe, T. P.; Chase, D. B.; Rabolt, J. F.

    2011-08-01

    An atomic force microscopy (AFM) probe is successfully utilized as an electrospinning tip for fabricating Nylon-6 nanofibers. The nanometre-size tip enabled controlled deposition of uniform polymeric nanofibers within a 1 cm diameter area. Nylon-6 nanofibers were continuously electrospun at a solution concentration as low as 1 wt% Nylon-6 in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). Wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) results of the AFM electrospun fibers indicated that the nanofibers predominantly display the meta-stable γ crystalline form suggesting rapid crystallization rate during the process. In addition to precise control over fiber deposition and diameter, some of the drawbacks of conventional electrospinning such as large volume of solutions and clogging of needles can be overcome using this AFM based electrospinning technique. Lastly, a comparison of electrospun fibers from syringe-needle based electrospinning and AFM probe-tip based electrospinning indicated significant morphological and microstructural differences in the case of AFM based electrospinning.

  16. Investigation on Dry Sliding Wear Behavior of Nylon66/GnP Nano-composite

    NASA Astrophysics Data System (ADS)

    Sankara Narayana, Kota; Suman, Koka Naga Sai; Arun Vikram, Kothapalli

    2017-04-01

    The tribological behavior of graphene nano platelets (GnP) reinforced Nylon66 polymer Nano composites were studied using a pin-on-disc apparatus under dry sliding conditions. The influence of wear control factors like applied load, velocity, sliding distance and weight percentage of GnP reinforcement on the responses like specific wear rate and frictional coefficient were investigated. Nano composites were developed by melt mixing of various weight fractions of GnP (0/0.5/1/2) with nylon 66 using twin screw extruder. A design of experiments based on the Taguchi technique was performed to acquire data in a controlled way and was successfully used to identify the optimal combinations of control factors influencing the outputs. Analysis of variance was employed to investigate the influence and contribution of control factors on the responses. The results showed that the inclusion of GnP as reinforcing material in Nylon66 Nano composites, decreases the friction coefficient and increases the wear resistance of the Nano composites significantly.

  17. Variable stiffness and recruitment using nylon actuators arranged in a pennate configuration

    NASA Astrophysics Data System (ADS)

    Kianzad, Soheil; Pandit, Milind; Lewis, Johnathan D.; Berlingeri, Alexander R.; Haebler, Karl J.; Madden, John D. W.

    2015-04-01

    In muscle variable impedance and ability to recruit fibers as needed helps enable actions such as walking and catching. A new biomimetic structure of nylon actuator is presented that imitates the human pennate muscle in structure, ability to vary stiffness and the ability to increase force by recruiting additional fibers. The actuator consists of 16 silver coated nylon coiled fibers attached to a central tendon at an angle of 20°. Each nylon coil produces 20 MPa of stress at constant length and nearly 20% strain at fixed load. Fibers are individually switched ON and OFF using transistors so that each element can be recruited, and the stiffness varied. The amount of input power is controlled with pulse width modulation (PWM) techniques. It is observed that the spring constant of the pennate structure varies from that of its passive state, 503 N/m and a resonance frequency of 1.4 Hz, to 1480 N/m with resonance frequency of 3.1 Hz in the active state where all the fibers are switched on under a 25 N load. Stiffness can be varied by a factor of 9.

  18. Measuring tropospheric HNO3 - Problems and prospects for Nylon filter and mist chamber techniques

    NASA Technical Reports Server (NTRS)

    Talbot, R. W.; Vijgen, A. S.; Harriss, R. C.

    1990-01-01

    A series of laboratory and field measurements was performed to evaluate the mist chamber technique for determining tropospheric HNO3 concentrations. Both the mist chamber and standard Nylon filter techniques exhibit high collection efficiency and excellent agreement measuring HNO3 vapors from a permeation source. When simultaneously sampling ambient air in eastern Virginia, the Nylon filter measured an average of 70 percent higher HNO3 concentration than the mist chamber technique. The results indicate that O3 causes a low-level positive artifact interference in HNO3 measurements performed with the filter technique. This O3-induced error is small, however, compared to the large difference between atmospheric HNO3 concentrations determined with the two techniques. It is hypothesized that unidentified (organic?) nitrogen species in the atmosphere react for form NO3(-) on the filter and this phenomenon may interfere with Nylon filter measurements of HNO3 vapor. These potential interferences did not appear to affect measurements of HNO3 with the mist chamber method.

  19. New technique to take samples from environmental surfaces using flocked nylon swabs.

    PubMed

    Hedin, G; Rynbäck, J; Loré, B

    2010-08-01

    Environmental surfaces near infected and/or colonised patients in hospitals are commonly contaminated with potentially pathogenic micro-organisms. At present, however, there is no standardised method for taking samples from surfaces in order to perform quantitative cultures. Usually contact plates or swabs are used, but these methods may give different results. The recovery rate of traditional swabbing, e.g. cotton or rayon, is poor. With a new type of swab utilising flocked nylon, the recovery may be enhanced up to three times compared with a rayon swab. In this study, we inoculated reference strains of Staphylococcus aureus and Enterococcus hirae onto a bedside table and took samples 1h later when inocula were dry. Sequential samples were taken from the same surface. A new sampling technique using two sequential nylon swabs for each sample was validated. The efficiency of the sampling, percentage recovery of the inoculum and the variation of culture results obtained from repeated experiments are described. Enhanced efficiency and higher recovery of inoculum were demonstrated using two sequential flocked nylon swabs for sampling.

  20. Investigation on Dry Sliding Wear Behavior of Nylon66/GnP Nano-composite

    NASA Astrophysics Data System (ADS)

    Sankara Narayana, Kota; Suman, Koka Naga Sai; Arun Vikram, Kothapalli

    2016-06-01

    The tribological behavior of graphene nano platelets (GnP) reinforced Nylon66 polymer Nano composites were studied using a pin-on-disc apparatus under dry sliding conditions. The influence of wear control factors like applied load, velocity, sliding distance and weight percentage of GnP reinforcement on the responses like specific wear rate and frictional coefficient were investigated. Nano composites were developed by melt mixing of various weight fractions of GnP (0/0.5/1/2) with nylon 66 using twin screw extruder. A design of experiments based on the Taguchi technique was performed to acquire data in a controlled way and was successfully used to identify the optimal combinations of control factors influencing the outputs. Analysis of variance was employed to investigate the influence and contribution of control factors on the responses. The results showed that the inclusion of GnP as reinforcing material in Nylon66 Nano composites, decreases the friction coefficient and increases the wear resistance of the Nano composites significantly.

  1. Experimental investigation of transport of discrete solids with surge flows in a 10.0 cm diameter partially filled pipe

    NASA Astrophysics Data System (ADS)

    Mahajan, B. M.

    1982-01-01

    The transport of discrete solids with surge flows in a partially filled slightly pitched horizontal pipe was investigated. The experimental apparatus, instrumentation, and procedures are described. The experiments were conducted using a cylindrical solid in a 10.0 cm (4 in) diameter pipe. The water surge flows were obtained by discharging different volumes of water into the pipe from a falling head open container which simulated a water closet. Flow induced solid velocities and stream depth histories at various locations along the length of the pipe were measured. The effects of water volume used, pipe slope, and size of the solid on the solid velocities were examined. Solid velocities were compared with the maximum water velocities estimated from the stream depth histories. Also, the distance traversed by the solids in the pipe were measured for those cases in which the solids did not clear the pipe. The solid velocity increased with an increase in water volume used, a decrease in the size of the solid, and an increase in the pipe slope. The solid velocity in the initial reach of the pipe was less than the maximum water velocity; and the solid velocity approaches the maximum water velocity as the solid traveled downstream, except for some experiments with small water volumes.

  2. Outcome of repair of chronic tear of the pectoralis major using corkscrew suture anchors by box suture sliding technique

    PubMed Central

    Joshi, Deepak; Jain, Jitesh Kumar; Chaudhary, Deepak; Singh, Utkarsh; Jain, Vineet; Lal, Ajay

    2016-01-01

    AIM To assess the functional and clinical results of repair of chronic tears of pectoralis major using corkscrew and sliding suture technique. METHODS In this retrospective study, we reviewed the results of pectoralis major repair in 11 chronic cases (> 6 wk) done between September 2011 and December 2014 at our institute. In all cases repair was done by same surgeon using corkscrew suture anchors and box suture sliding technique. At 6 mo, after surgery magnetic resonance imaging was done to see the integrity of the repair. Functional evaluation was done using Penn and ASES scores. Pre and postoperative Isokinetic strength was measured. RESULTS Average follow-up was 48.27 ± 21.0 mo. The Wilcoxon signed rank test was used to evaluate the outcome scores. The average ASES score increased from an average of 54.63 ± 13.0 preoperatively to 95.09 ± 2.60 after surgery at their last follow-up. The average Penn score also increased from 5.72 ± 0.78, 2.81 ± 1.32 and 45.81 ± 1.72 to 9.36 ± 0.80, 8.27 ± 0.90 and 59 ± 1.34 for pain, satisfaction and function respectively. Follow up magnetic resonance imaging (MRI) (at 6 mo) showed continuity and the bulk of pectoralis major muscle in all cases. Average isokinetic strength deficiency in horizontal adduction at 60° was 13.63% ± 6.93% and at 120° was 10.18% ± 4.93% and in flexion at 60° was 10.72% ± 5.08% and at 120° was 6.63% + 3.74%. Results showed that both ASES and Penn score improved significantly (2 tailed P value = 0.0036). CONCLUSION We could conclude from this series that pectoralis major repair even in chronic cases using 5.5 mm corkscrew anchors give excellent functional and cosmetic results. In chronic cases the repairable length of the tendon is not available and sliding suture technique allows for fixation of worn out tendomuscular junction to bone without letting cutting through the muscle. PMID:27795949

  3. Suturing and extensional reactivation in the Grenville orogen, Canada

    NASA Astrophysics Data System (ADS)

    Busch, Jay P.; Mezger, Klaus; van der Pluijm, Ben A.

    1997-06-01

    Sutures are zones of weakness within orogenic belts that have the potential to become reactivated during orogenic evolution. The Robertson Lake shear zone marks a major tectonic boundary in the southeastern Grenville orogen of Canada that has been intermittently active for at least 130 m.y. The shear zone played a major role in the compressional stage of the orogenic cycle as well as during postorogenic collapse. The zone separates the Elzevir terrane to the west and the Frontenac terrane to the east. Sphene ages (U-Pb) indicate that these two terranes have distinct tectonothermal histories and that the shear zone represents a “cryptic suture.” In its current state, the shear zone is a low angle (30°ESE dip) plastic to brittle extensional shear zone that separates the Mazinaw (footwall) and Sharbot Lake (hanging wall) domains. Integration of structural, metamorphic, and chronologic data leads to a model that describes the complete evolution of this fundamental tectonic boundary that evolved from an early compressional zone (ca. 1030 Ma) to a late extensional zone (until at least 900 Ma).

  4. Assessing suturing techniques using a virtual reality surgical simulator.

    PubMed

    Kazemi, Hamed; Rappel, James K; Poston, Timothy; Hai Lim, Beng; Burdet, Etienne; Leong Teo, Chee

    2010-09-01

    Advantages of virtual-reality simulators surgical skill assessment and training include more training time, no risk to patient, repeatable difficulty level, reliable feedback, without the resource demands, and ethical issues of animal-based training. We tested this for a key subtask and showed a strong link between skill in the simulator and in reality. Suturing performance was assessed for four groups of participants, including experienced surgeons and naive subjects, on a custom-made virtual-reality simulator. Each subject tried the experiment 30 times using five different types of needles to perform a standardized suture placement task. Traditional metrics of performance as well as new metrics enabled by our system were proposed, and the data indicate difference between trained and untrained performance. In all traditional parameters such as time, number of attempts, and motion quantity, the medical surgeons outperformed the other three groups, though differences were not significant. However, motion smoothness, penetration and exit angles, tear size areas, and orientation change were statistically significant in the trained group when compared with untrained group. This suggests that these parameters can be used in virtual microsurgery training.

  5. Stapler suture of the pharynx after total laryngectomy.

    PubMed

    Dedivitis, R A; Aires, F T; Pfuetzenreiter, E G; Castro, M A F; Guimarães, A V

    2014-04-01

    The use of a stapler for pharyngeal closure during total laryngectomy was first described in 1971. It provides rapid watertight closure without surgical field contamination. The objective of our study was to compare the incidence of pharyngocutaneous fistula after total laryngectomy with manual and mechanical closures of the pharynx. This was a non-randomised, prospective clinical study conducted at two tertiary medical centres from 1996 to 2011 including consecutive patients with laryngeal tumours who underwent total laryngectomy. We compared the incidence of pharyngocutaneous fistula between two groups of patients: in 20 patients, 75 mm linear stapler closure was applied, whereas in 67 patients a manual suture was used. Clinical data were compared between groups. The groups were statistically similar in terms of gender, age, diabetes mellitus, smoking and alcohol consumption and tumour site. The group of patients who underwent stapler-assisted pharyngeal closure had a higher number of patients with previous tracheotomy (p < 0.001) and previous chemoradiation (p < 0.001). The incidence of pharyngocutaneous fistula was 30% in the mechanical closure group and 20.9% in the manual suture group (p = 0.42). In conclusion the use of the stapler does not increase the rate of fistulae.

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

    PubMed

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

    2015-10-14

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

  7. An "in vitro" tensile strength study on suturing technique and material.

    PubMed

    González-Barnadas, Albert; Camps-Font, Octavi; Espanya-Grifol, Dunia; España-Tost, Antoni; Figueiredo, Rui; Valmaseda-Castellón, Eduard

    2017-03-16

    Suture technique and materials are important in preventing complications like wound dehiscences. The purpose of this study was to determine the tensile strength of different suturing techniques, comparing several materials with different diameters. One hundred and sixty sutures were performed using silk, e-PTFE and two types of polyamide (monofilament and Supramid®). Ten simple, 10 horizontal mattress and 10 combinations of the two stitches were performed with the 4-0 gauge of each material. Additionally, 10 simple sutures were performed with the 5-0 gauge of each material. The maximum tensile force resisted by each suture was recorded. When 5mm of traction were applied, the polyamide monofilament resisted significantly better without untying or breaking compared with Supramid® or silk, while e-PTFE was superior to all the others. However, the force when the e-PTFE 4-0 sutures untied or broke was lower than for either type of polyamide. The combined technique withstood a significantly higher tensile force before unknotting or breaking than the simple and mattress stitches. The 5-0 gauges of silk and both types of polyamide showed lower tensile strengths than the 4-0 materials. Among the 5-0 sutures, Supramid® showed a higher tensile strength than silk. The combined suture technique possesses greater tensile strength than a simple or a horizontal mattress suture and e-PTFE 4-0 withstands more traction without untying or breaking than all the other materials, although at a lower tensile force. With the exception of e-PTFE, 4-0 sutures have greater tensile strength than 5-0 sutures.

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

    NASA Astrophysics Data System (ADS)

    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

  9. Preparation and properties of banana fiber-reinforced composites based on high density polyethylene (HDPE)/Nylon-6 blends.

    PubMed

    Liu, H; Wu, Q; Zhang, Q

    2009-12-01

    Banana fiber (BaF)-filled composites based on high density polyethylene (HDPE)/Nylon-6 blends were prepared via a two-step extrusion method. Maleic anhydride grafted styrene/ethylene-butylene/styrene triblock polymer (SEBS-g-MA) and maleic anhydride grafted polyethylene (PE-g-MA) were used to enhance impact performance and interfacial bonding between BaF and the resins. Mechanical, crystallization/melting, thermal stability, water absorption, and morphological properties of the composites were investigated. In the presence of SEBS-g-MA, better strengths and moduli were found for HDPE/Nylon-6 based composites compared with corresponding HDPE based composites. At a fixed weight ratio of PE-g-MA to BaF, an increase of BaF loading up to 48.2 wt.% led to a continuous improvement in moduli and flexural strength of final composites, while impact toughness was lowered gradually. Predicted tensile modulus by the Hones-Paul model for three-dimensional random fiber orientation agreed well with experimental data at the BaF loading of 29.3 wt.%. However, the randomly-oriented fiber models underestimated experimental data at higher fiber levels. It was found that the presence of SEBS-g-MA had a positive influence on reinforcing effect of the Nylon-6 component in the composites. Thermal analysis results showed that fractionated crystallization of the Nylon-6 component in the composites was induced by the addition of both SEBS-g-MA and PE-g-MA. Thermal stability of both composite systems differed slightly, except an additional decomposition peak related to the minor Nylon-6 for the composites from the HDPE/Nylon-6 blends. In the presence of SEBS-g-MA, the addition of Nylon-6 and increased BaF loading level led to an increase in the water absorption value of the composites.

  10. A new technique to improve the mechanical and biological performance of ultra high molecular weight polyethylene using a nylon coating.

    PubMed

    Firouzi, Dariush; Youssef, Aya; Amer, Momen; Srouji, Rami; Amleh, Asma; Foucher, Daniel A; Bougherara, Habiba

    2014-04-01

    A new patent pending technique is proposed in this study to improve the mechanical and biological performance of ultra high molecular weight polyethylene (UHMWPE), i.e., to uniformly coat nylon onto the UHMWPE fiber (Firouzi et al., 2012). Mechanical tests were performed on neat and new nylon coated UHMWPE fibers to examine the tensile strength and creep resistance of the samples at different temperatures. Cytotoxicity and osteolysis induced by wear debris of the materials were investigated using (MTT) assay, and RT-PCR for tumor necrosis factor alpha (TNFα) and interleukin 6 (IL-6) osteolysis markers. Mechanical test results showed substantial improvement in maximum creep time, maximum breaking force, and toughness values of Nylon 6,6 and Nylon 6,12 coated UHMWPE fibers between average 15% and 60% at 25, 50, and 70°C. Furthermore, cytotoxicity studies have demonstrated significant improvement in cell viability using the nylon coated UHMWPE over the neat one (72.4% vs 54.8%) for 48h and (80.7 vs 5%) for 72h (P<0.01). Osteolysis test results have shown that the expression levels of TNFα and IL-6 markers induced by the neat UHMWPE fiber were significantly higher than those induced by the Nylon 6,6 coated UHMWPE (2.5 fold increase for TNFα at 48h, and three fold increase for IL-6 at 72h (P<0.01)). This study suggests that UHMWPE coated with nylon could be used as a novel material in clinical applications with lower cytotoxicity, less wear debris-induced osteolysis, and superior mechanical properties compared to neat UHMWPE.

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

    ERIC Educational Resources Information Center

    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…

  12. 21 CFR 878.4494 - Absorbable poly(hydroxybutyrate) surgical suture produced by recombinant DNA technology.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Absorbable poly(hydroxybutyrate) surgical suture 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...

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

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Absorbable poly(hydroxybutyrate) surgical suture 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...

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

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Absorbable poly(hydroxybutyrate) surgical suture 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...

  15. Barbed Suture: A Review of the Technology and Clinical Uses in Obstetrics and Gynecology

    PubMed Central

    Greenberg, James A; Goldman, Randi H

    2013-01-01

    Surgical knots are simply a necessary evil needed to anchor smooth suture to allow it to function in its role in tissue reapproximation. Surgical knots reduce the tensile strength of all sutures by thinning and stretching the material. The tying of surgical knots introduces the potential of human error and interuser variability. Knot-secured smooth suture must create an uneven distribution of tension across the wound with the higher tension burdens placed at the knots. Given the excessive relative wound tension on the knot and the reasonable concerns of surgeons for suture failure due to knot slippage, there is a natural tendency toward overcoming these concerns by over-tightening knots; however, tighter knots may be worse for wound healing and strength than looser knots. In minimally invasive laparoscopic surgeries, the ability to quickly and properly tie surgical knots presents a new challenge. In cases in which knot tying is difficult, the use of knotless barbed suture can securely reapproximate tissues with less time, cost, and aggravation. This article reviews the technology behind barbed sutures with a focus on understanding how they differ from traditional smooth sutures and how barbed sutures have performed in in vitro and animal model testing, as well as in human clinical trials. PMID:24920976

  16. Skull sutures: Changing morphology during preadolescent growth and its implications in forensic identification.

    PubMed

    Jayaprakash, Paul T; Srinivasan, G J

    2013-06-10

    Forensic identification of juvenile skulls is a problem area. Although the skull suture patterns have been suggested for use in individualizing human remains by comparing antemortem and postmortem radiographs, the age at which such patterns stabilize and can be useful for identification had been indicated as 7 years. Subsequent researchers have also concurred that antemortem and postmortem radiographs taken after the 7th year would be sufficient to meet the Daubert standard criteria for identifying skulls using radiographs. The suggestions regarding the lower age limit for stabilization of suture patterns have not been verified so far. In this research, the patterns of the sutures in the ectocranial and endocranial surfaces of the lambdoid region in 22 juvenile skulls (age range 1-10 years) and 100 adult skulls (age range 17-70 years) were studied for the relative incidence of different types of suture patterns. The radiographic recordings of the suture patterns in the juvenile skulls were also compared with the patterns seen in the ectocranial and endocranial surfaces. The findings of this study support the proposition that the suture patterns are plastic during the juvenile stage and that they undergo significant remodeling during growth into adulthood. Indicating the possibility of growth related alterations in the sutural morphology, the onset of adulthood is suggested as the age for stabilization of suture patterns in the context of prescribing standards for such criteria as those relating to Daubert.

  17. A mathematical model for mechanotransduction at the early steps of suture formation

    PubMed Central

    Khonsari, R. H.; Olivier, J.; Vigneaux, P.; Sanchez, S.; Tafforeau, P.; Ahlberg, P. E.; Di Rocco, F.; Bresch, D.; Corre, P.; Ohazama, A.; Sharpe, P. T.; Calvez, V.

    2013-01-01

    Growth and patterning of craniofacial sutures is subjected to the effects of mechanical stress. Mechanotransduction processes occurring at the margins of the sutures are not precisely understood. Here, we propose a simple theoretical model based on the orientation of collagen fibres within the suture in response to local stress. We demonstrate that fibre alignment generates an instability leading to the emergence of interdigitations. We confirm the appearance of this instability both analytically and numerically. To support our model, we use histology and synchrotron X-ray microtomography and reveal the fine structure of fibres within the sutural mesenchyme and their insertion into the bone. Furthermore, using a mouse model with impaired mechanotransduction, we show that the architecture of sutures is disturbed when forces are not interpreted properly. Finally, by studying the structure of sutures in the mouse, the rat, an actinopterygian (Polypterus bichir) and a placoderm (Compagopiscis croucheri), we show that bone deposition patterns during dermal bone growth are conserved within jawed vertebrates. In total, these results support the role of mechanical constraints in the growth and patterning of craniofacial sutures, a process that was probably effective at the emergence of gnathostomes, and provide new directions for the understanding of normal and pathological suture fusion. PMID:23516237

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

    PubMed

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

    2002-02-07

    The shape of sea urchins may be determined mechanically by patterns of force analogous to those that determine the shape of a water droplet. This mechanical analogy implies skeletal flexibility at the time of growth. Although comprised of many rigid calcite plates, sutural collagenous ligaments could confer such flexibility if the sutures between plates loosened and acted as joints at the time of growth. We present experimental evidence of such flexibility associated with weight gain and growth. Over 13-, 4-, and 2-week periods, fed urchins (Strongylocentrotus droebachiensis) gained weight and developed looser sutures than unfed urchins that maintained or lost weight. Further, skeletons of fed urchins force-relaxed more than did those of unfed urchins and urchins with loose sutures force-relaxed more than those with tight sutures. Urchins (Strongylocentrotus franciscanus) fed for two and a half weeks, gained weight, also had looser skeletons and deposited calcite at sutural margins, whereas unfed ones did not. In field populations of S. droebachiensis the percentage having loose sutures varied with urchin diameter and reflected their size-specific growth rate. The association between feeding, weight gain, calcite deposition, force relaxation and sutural looseness supports the hypothesis that urchins deform flexibly while growing, thus determining their drop-like shapes.

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

    PubMed Central

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

    2002-01-01

    The shape of sea urchins may be determined mechanically by patterns of force analogous to those that determine the shape of a water droplet. This mechanical analogy implies skeletal flexibility at the time of growth. Although comprised of many rigid calcite plates, sutural collagenous ligaments could confer such flexibility if the sutures between plates loosened and acted as joints at the time of growth. We present experimental evidence of such flexibility associated with weight gain and growth. Over 13-, 4-, and 2-week periods, fed urchins (Strongylocentrotus droebachiensis) gained weight and developed looser sutures than unfed urchins that maintained or lost weight. Further, skeletons of fed urchins force-relaxed more than did those of unfed urchins and urchins with loose sutures force-relaxed more than those with tight sutures. Urchins (Strongylocentrotus franciscanus) fed for two and a half weeks, gained weight, also had looser skeletons and deposited calcite at sutural margins, whereas unfed ones did not. In field populations of S. droebachiensis the percentage having loose sutures varied with urchin diameter and reflected their size-specific growth rate. The association between feeding, weight gain, calcite deposition, force relaxation and sutural looseness supports the hypothesis that urchins deform flexibly while growing, thus determining their drop-like shapes. PMID:11839189

  20. Medical treatment of craniosynostosis: Recombinant Noggin inhibits coronal suture closure in the rat craniosynostosis model

    PubMed Central

    Shen, K; Krakora, SM; Cunningham, M; Singh, M; Wang, X; Hu, FZ; Post, JC; Ehrlich, GD

    2009-01-01

    Introduction The mechanisms underlying craniosynostosis remains unknown. However, mutations in FGFR2 are associated with craniosynostotic syndromes. We previously compared gene expression patterns of patent and synostosing coronal sutures in the nude rat and demonstrated down regulation of Noggin in synostosing sutures. Noggin expression is also suppressed by FGF2 and constitutive FGFR2 signaling.(1–2) Thus, we therefore hypothesized that the addition of rhNoggin to prematurely fusing sutures should prevent synostosis. Materials and Methods Cohorts of nude rats were subjected to: 1) surgical elevation of the coronal suture (shams); 2) surgical elevation and placement of normal or FGFR2 mutant human osteoblasts onto the underlying dura (xenotranplants); or 3) xenotransplantation with co-application of heparin acrylic beads soaked with recombinant human (rh) Noggin. Eleven days post surgery the sutures were harvested, stained, and histologically examined. Results Animals that received control osteoblasts, sham surgery, or no surgery demonstrated normal skull growth and coronal suture histology, whereas animals transplanted only with FGFR2 mutant osteoblasts showed evidence of bridging synostosis on the calvarial dural surface. Sutures treated with FGFR2 mutant osteoblasts and rhNoggin remained patent. Conclusion The chimeric nude rate model is a viable model of craniosynostosis. FGFR2 mutations in osteoblasts induce bridging osteosynthesis demonstrating one of the mechanisms for premature suture fusion. Topical application of rhNoggin protein prevents craniosynostosis in the weanling nude rat xenotransplantation model of syndromic craniosynostosis. PMID:19627528

  1. Clinical and pathological assessment of different suture techniques for microvascular anastomosis in rat femoral artery

    PubMed Central

    El-Shazly, Mohamed

    2007-01-01

    This study examined the clinical and pathological features after a microvascular anastomosis of a rat femoral artery using four different suture techniques. Sixty Sprage-Dawely rats were divided randomly into 4 groups. Fifteen bisected arteries (one from each animal) in Group I, II, III and IV were sutured with the simple interrupted suture, continuous suture, sleeve suture and cuff suture, respectively. The anastomosis times in Group I, II, III and IV were 28.67, 14.67, 15.47 and 15.93 min, respectively. Immediate bleeding that stopped without intervention (grade I) was observed in 67%, 73% and 60% of the anastomosed vessels in Groups II, III and IV, respectively, while 60% of the vessels in Group I showed light bleeding that was inhibited by gentile pressure (grade II). All vessels examined appeared to be patent at 5 and 15 min after the anastomosis. On the 7th day postoperatively, the vessels of Group I showed the highest patency rate (93%) compared with Groups II (67%), III (73%) and IV (87%). Moreover, there were more pronounced pathological changes in Group I than in the other groups. These changes included endothelial loss, endothelial proliferation, degeneration and necrosis of the tunica media. Suture materials surrounded by an inflammatory reaction were also observed. In conclusion, the simple interrupted suture is preferable for microvascular anastomosis due to its highest patency rate. The other techniques investigated can be good alternatives because of their short anastomotic time and moderate pathological changes. PMID:17679774

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

    PubMed Central

    Bright, Jen A.

    2012-01-01

    Craniofacial sutures are a ubiquitous feature of the vertebrate skull. Previous experimental work has shown that bone strain magnitudes and orientations often vary when moving from one bone to another, across a craniofacial suture. This has led to the hypothesis that craniofacial sutures act to modify the strain environment of the skull, possibly as a mode of dissipating high stresses generated during feeding or impact. This study tests the hypothesis that the introduction of craniofacial sutures into finite element (FE) models of a modern domestic pig skull would improve model accuracy compared to a model without sutures. This allowed the mechanical effects of sutures to be assessed in isolation from other confounding variables. These models were also validated against strain gauge data collected from the same specimen ex vivo. The experimental strain data showed notable strain differences between adjacent bones, but this effect was generally not observed in either model. It was found that the inclusion of sutures in finite element models affected strain magnitudes, ratios, orientations and contour patterns, yet contrary to expectations, this did not improve the fit of the model to the experimental data, but resulted in a model that was less accurate. It is demonstrated that the presence or absence of sutures alone is not responsible for the inaccuracies in model strain, and is suggested that variations in local bone material properties, which were not accounted for by the FE models, could instead be responsible for the pattern of results. PMID:22363727

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

    PubMed Central

    Laas, Enora; Poilroux, Cécile; Bézu, Corinne; Coutant, Charles; Uzan, Serge; Rouzier, Roman; Chéreau, Elisabeth

    2012-01-01

    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) (P < 10−4). There was a significant difference in Group 2 between predicted probabilities and observed percentages (P < 10−5). 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. PMID:23316373

  4. A novel suture retention test for scaffold strength characterization in ophthalmology.

    PubMed

    Küng, Florian; Schubert, Dirk W; Stafiej, Piotr; Kruse, Friedrich E; Fuchsluger, Thomas A

    2016-12-01

    Sutures are a common way to attach scaffolds in patients. For tubular cardiac scaffolds, the 'suture retention strength' is commonly used to evaluate the resistance of a scaffold against the pull-out of a suture. In order to make this quantity accessible for ophthalmological scaffolds the test procedure has been modified in a novel way. Polycaprolactone (PCL) films of different thicknesses and an amniotic membrane (AM) were used for the experiments. Circular samples with a radius of 7mm were taken and a suture was passed through each sample and tied to a loop. The sample was clamped in a tensile tester and a bolt was passed through the loop. The suture was then pulled with a constant deformation rate until pull-out occurred. The suture retention strength, the deformation at the suture retention strength, and the deformation at rupture were determined for each sample. The presented modified suture retention test allows to measure the relevant parameters of samples on the scale of ophthalmological scaffolds in a reproducible way. A comparison between the first data on PCL and AM has been made.

  5. [Assessment of the effectiveness of the suture with triclosan coated in emergency surgery].

    PubMed

    Darvin, V V; Lobanov, D S; Krasnov, E A; Gvozdetsky, A N

    2017-01-01

    The aim of the study was to evaluate the effectiveness of the suture with a coating of triclosan on the dynamics of postoperative course in emergency surgical patients, comparing the postoperative period in the application of the suture with coating and without it.

  6. 21 CFR 878.5000 - Nonabsorbable poly(ethylene terephthalate) surgical suture.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nonabsorbable poly(ethylene terephthalate... Devices § 878.5000 Nonabsorbable poly(ethylene terephthalate) surgical suture. (a) Identification. Nonabsorbable poly(ethylene terephthalate) surgical suture is a multifilament, nonabsorbable, sterile,...

  7. Accuracy of Suture Passage During Arthroscopic Remplissage—What Anatomic Landmarks Can Improve It?

    PubMed Central

    Garcia, Grant H.; Degen, Ryan M.; Liu, Joseph N.; Kahlenberg, Cynthia A.; Dines, Joshua S.

    2016-01-01

    Background: Recent data suggest that inaccurate suture passage during remplissage may contribute to a loss of external rotation, with the potential to cause posterior shoulder pain because of the proximity to the musculotendinous junction. Purpose: To evaluate the accuracy of suture passage during remplissage and identify surface landmarks to improve accuracy. Study Design: Descriptive laboratory study. Methods: Arthroscopic remplissage was performed on 6 cadaveric shoulder specimens. Two single-loaded suture anchors were used for each remplissage. After suture passage, position was recorded in reference to the posterolateral acromion (PLA), with entry perpendicular to the humeral surface. After these measurements, the location of posterior cuff penetration was identified by careful surgical dissection. Results: Twenty-four sutures were passed in 6 specimens: 6 sutures (25.0%) were correctly passed through the infraspinatus tendon, 12 (50%) were through the infraspinatus muscle or musculotendinous junction (MTJ), and 6 (25%) were through the teres minor. Suture passage through the infraspinatus were on average 25 ± 5.4 mm inferior to the PLA, while sutures passing through the teres minor were on average 35.8 ± 5.7 mm inferior to the PLA. There was an odds ratio of 25 (95% CI, 2.1-298.3; P < .001) that the suture would be through the infraspinatus if the passes were less than 3 cm inferior to the PLA. Sutures passing through muscle and the MTJ were significantly more medial than those passing through tendon, measuring on average 8.1 ± 5.1 mm lateral to the PLA compared with 14.5 ± 5.5 mm (P < .02). If suture passes were greater than 1 cm lateral to the PLA, it was significantly more likely to be in tendon (P = .013). Conclusion: We found remplissage suture passage was inaccurate, with only 25% of sutures penetrating the infraspinatus tendon. Passing sutures 1 cm lateral and within 3 cm inferior of the PLA improves the odds of successful infraspinatus tenodesis

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

    PubMed Central

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

    2008-01-01

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

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

    PubMed Central

    Li, Zhanrong; Yao, Lin; Li, Jingguo; Zhang, Wenxin; Wu, Xianghua; Liu, Yi; Lin, Miaoli; Su, Wenru; Li, Yongping; Liang, Dan

    2012-01-01

    Purpose Celastrol, a traditional Chinese medicine, is widely used in anti-inflammation and anti-angiogenesis research. However, the poor water solubility of celastrol restricts its further application. This paper aims to study the effect of celastrol nanoparticles (CNPs) on corneal neovascularization (CNV) and determine the possible mechanism. Methods To improve the hydrophilicity of celastrol, celastrol-loaded poly(ethylene glycol)-block-poly(ɛ-caprolactone) nanopolymeric micelles were developed. The characterization of CNPs was measured by dynamic light scattering and transmission electron microscopy analysis. Celastrol loading content and release were assessed by ultraviolet-visible analysis and high performance liquid chromatography, respectively. In vitro, human umbilical vein endothelial cell proliferation and capillary-like tube formation were assayed. In vivo, suture-induced CNV was chosen to evaluate the effect of CNPs on CNV in rats. Immunohistochemistry for CD68 assessed the macrophage infiltration of the cornea on day 6 after surgery. Real-time quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay were used to evaluate the messenger ribonucleic acid and protein levels, respectively, of vascular endothelial growth factor, matrix metalloproteinase 9, and monocyte chemoattractant protein 1 in the cornea. Results The mean diameter of CNPs with spherical shape was 48 nm. The celastrol loading content was 7.36%. The release behavior of CNPs in buffered solution (pH 7.4) showed a typical two-phase release profile. CNPs inhibited the proliferation of human umbilical vein endothelial cells in a dose-independent manner and suppressed the capillary structure formation. After treatment with CNPs, the length and area of CNV reduced from 1.16 ± 0.18 mm to 0.49 ± 0.12 mm and from 7.71 ± 0.94 mm2 to 2.29 ± 0.61 mm2, respectively. Macrophage infiltration decreased significantly in the CNP-treated corneas. CNPs reduced

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    Multi-scale, finite-frequency tomography across the Himalayas-Tibet shows a clear, subhorizontal anomaly of high VP and VSin the upper mantle that can be traced from under N. India all the way to beneath central Tibet. This configuration of the "Greater India" (GI), or the submerged, northern portion of the Indian shield, is combined with other constraints to reconstruct position of the Indian lithospheric mantle (ILM) relative to Asia back to about 15 Ma ago, or the onset of the latest magmatic activity in Tibet. By then, the leading edge of the ILM (Indian mantle front, IMF) has advanced subhorizontally past the entire Lhasa terrane and also probably have caused the lithospheric mantle beneath the Qiangtang terrane to thicken. The thickening is likely to have led to Rayleigh-Taylor instability, causing widespread but small volume of magmatic activity in northern Tibet. Meanwhile, the detached lithospheric mantle foundered through the upper mantle to rest at the bottom of the mantle transition zone (MTZ), just above the lower mantle. This detached lithospheric mantle manifests itself as a large-scale seismic anomaly of high compressional wave speed (VP) but curiously is undetectable through shear-waves. Based on laboratory data for nominally anhydrous olivine and its high-pressure polymorphs (NAO), the discordant results between P- and S-waves is explained by abundant hydroxyls in the foundered lithospheric mantle, a hypothesis supported by other evidences as well. Since NAO can hold ~1 wt% of water throughout the upper mantle and the MTZ, foundering of thickened lithospheric mantle caused by continental collision is an under-appreciated but effective pathway for water to enter the deep mantle. Currently, the Indus-Yarlung suture between northern India and the Lhasa terrane appears to be an inactive, crustal feature, as the GI continues to pass beneath it. On the other hand, even though the IMF has now advanced northward beyond the Bangong-Nujiang suture (BNS

  11. Ectocranial suture closure in Pan troglodytes and Gorilla gorilla: pattern and phylogeny.

    PubMed

    Cray, James; Meindl, Richard S; Sherwood, Chet C; Lovejoy, C Owen

    2008-08-01

    The order in which ectocranial sutures undergo fusion displays species-specific variation among primates. However, the precise relationship between suture closure and phylogenetic affinities is poorly understood. In this study, we used Guttman Scaling to determine if the modal progression of suture closure differs among Homo sapiens, Pan troglodytes, and Gorilla gorilla. Because DNA sequence homologies strongly suggest that P. troglodytes and Homo sapiens share a more recent common ancestor than either does with G. gorilla, we hypothesized that this phylogenetic relationship would be reflected in the suture closure patterns of these three taxa. Results indicated that while all three species do share a similar lateral-anterior closure pattern, G. gorilla exhibits a unique vault pattern, which, unlike humans and P. troglodytes, follows a strong posterior-to-anterior gradient. P. troglodytes is therefore more like Homo sapiens in suture synostosis.

  12. Effects of myrrh on the strength of suture materials: an in vitro study.

    PubMed

    Alshehri, Mohammed A; Baskaradoss, Jagan Kumar; Geevarghese, Amrita; Ramakrishnaiah, Ravikumar; Tatakis, Dimitris N

    2015-01-01

    The present in vitro study sought to determine the effects of myrrh-containing solutions on common suture materials used in periodontal surgery. Three commonly used suture materials (silk, polyglactin 910, polytetrafluoroethylene) were immersed in four thermostatically controlled experimental media to simulate daily oral rinsing activity, namely -artificial saliva, normal saline solution with 0.2% Commiphora myrrh, full-concentration (100%) Commiphora myrrh oil, and a myrrh-containing commercial mouthwash. Tensile strength was measured at the end of each day using an Instron tensile testing machine. Silk sutures were susceptible to tensile strength loss when exposed to 0.2% myrrh solution once daily for 5 days. Myrrh-containing commercial mouthwash had no effect on tensile strength, but all three suture materials lost tensile strength when exposed to 100% myrrh oil. For patients that routinely use myrrh mouthwashes postoperatively, findings of this study suggested that silk sutures might not be the optimal material choice.

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

    PubMed Central

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

    2012-01-01

    Summary Introduction: Several techniques can be performed to improve nasal tip definition such as cartilage resection, tip grafts, or sutures. Objctive: To evaluate the outcome of lateral intercrural suture at the lower lateral cartilage by endonasal rhinoplasty with a basic technique without delivery in decreasing the angle of domal divergence and improving the nasal tip definition. Method: This prospective study was performed in 64 patients in which a suture was made on the board head of the lower lateral cartilage in the joint between the dome and lateral crus, using polydioxanone (PDS) with sharp, curved needle. Results: In all of the cases, better definition of the nasal tip was achieved by intercrural suturing for at least 6 months postoperatively. Conclusion: Lateral intercrural suture of the lower lateral cartilage provides improved nasal tip definition and can be performed by endonasal rhinoplasty without delivery in the Caucasian nose. PMID:25991941

  14. Microbiology of Explanted Suture Segments from Infected and Noninfected Surgical Patients

    PubMed Central

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

    2013-01-01

    Sutures under selective host/environmental factors can potentiate postoperative surgical site infection (SSI). The present investigation characterized microbial recovery and biofilm formation from explanted absorbable (AB) and nonabsorbable (NAB) sutures from infected and noninfected sites. AB and NAB sutures were harvested from noninfected (70.9%) and infected (29.1%) sites in 158 patients. At explantation, devices were sonicated and processed for qualitative/quantitative bacteriology; selective sutures were processed for scanning electron microscopy (SEM). Bacteria were recovered from 85 (53.8%) explanted sites; 39 sites were noninfected, and 46 were infected. Suture recovery ranged from 11.1 to 574.6 days postinsertion. A significant difference in mean microbial recovery between noninfected (1.2 isolates) and infected (2.7 isolates) devices (P < 0.05) was noted. Staphylococcus epidermidis, Staphylococcus aureus, coagulase-negative staphylococci (CNS), Peptostreptococcus spp., Bacteroides fragilis, Escherichia coli, Enterococcus spp., Pseudomonas aeruginosa, and Serratia spp. were recovered from infected devices, while commensal skin flora was recovered from noninfected devices. No significant difference in quantitative microbial recovery between infected monofilament and multifilament sutures was noted. Biofilm was present in 100% and 66.6% of infected and noninfected devices, respectively (P < 0.042). We conclude that both monofilament and braided sutures provide a hospitable surface for microbial adherence: (i) a significant difference in microbial recovery from infected and noninfected sutures was noted, (ii) infected sutures harbored a mixed flora, including multidrug-resistant health care-associated pathogens, and (iii) a significant difference in the presence or absence of a biofilm in infected versus noninfected explanted devices was noted. Further studies to document the benefit of focused risk reduction strategies to minimize suture contamination and

  15. Ultrasonography in the evaluation of the mid-palatal suture in rapid palatal expansion

    PubMed Central

    Gumussoy, I; Bayrakdar, I S; Dagistan, S; Caglayan, F

    2014-01-01

    Objectives: Orthodontists usually evaluate the mid-palatal sutural opening with occlusal radiography. The purpose of this article is to evaluate the sutural opening with ultrasonography (USG) in a series of patients undergoing rapid palatal expansion (RPE). Methods: The study included 87 USG images and 87 occlusal radiographs from 29 healthy patients (mean age, 13.9 years; range, 11–20 years; boys, 12; girls, 17) who required RPE treatment. The sutural opening was assessed with USG, and the amount of sutural expansion as mesiodistal length was measured immediately after appliance practice (T0), 10 turns (T1) and 20 turns (T2) during the expansion period. Sutural expansion evaluated by occlusal radiographs was scored at every stage. Measurements obtained by USG and scores observed in the occlusal radiographs were compared by non-parametric Kendall's tau test. Results: Both USG and radiographic images revealed normal anatomical structure during pre-expansion (stage T0). On USG, sutural expansion was seen in 19 patients at stage T1. There was no expansion at this stage in ten patients. At stage T2, on USG and radiography, an increase in the amount of expansion was observed in 19 patients with sutural expansion at stage T1 and sutural expansion was observed in 5 patients without sutural expansion at stage T1. No expansion was observed at both stages T1 and T2 in five patients. USG measurements and occlusal scores in both T1 and T2 turns showed statistically significant correlation (p < 0.001). Conclusions: The results indicate that USG might be a useful method to assess mid-palatal sutural opening in patients undergoing RPE. PMID:25168810

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

    PubMed

    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.

  17. MicroArray Facility: a laboratory information management system with extended support for Nylon based technologies

    PubMed Central

    Honoré, Paul; Granjeaud, Samuel; Tagett, Rebecca; Deraco, Stéphane; Beaudoing, Emmanuel; Rougemont, Jacques; Debono, Stéphane; Hingamp, Pascal

    2006-01-01

    Background High throughput gene expression profiling (GEP) is becoming a routine technique in life science laboratories. With experimental designs that repeatedly span thousands of genes and hundreds of samples, relying on a dedicated database infrastructure is no longer an option. GEP technology is a fast moving target, with new approaches constantly broadening the field diversity. This technology heterogeneity, compounded by the informatics complexity of GEP databases, means that software developments have so far focused on mainstream techniques, leaving less typical yet established techniques such as Nylon microarrays at best partially supported. Results MAF (MicroArray Facility) is the laboratory database system we have developed for managing the design, production and hybridization of spotted microarrays. Although it can support the widely used glass microarrays and oligo-chips, MAF was designed with the specific idiosyncrasies of Nylon based microarrays in mind. Notably single channel radioactive probes, microarray stripping and reuse, vector control hybridizations and spike-in controls are all natively supported by the software suite. MicroArray Facility is MIAME supportive and dynamically provides feedback on missing annotations to help users estimate effective MIAME compliance. Genomic data such as clone identifiers and gene symbols are also directly annotated by MAF software using standard public resources. The MAGE-ML data format is implemented for full data export. Journalized database operations (audit tracking), data anonymization, material traceability and user/project level confidentiality policies are also managed by MAF. Conclusion MicroArray Facility is a complete data management system for microarray producers and end-users. Particular care has been devoted to adequately model Nylon based microarrays. The MAF system, developed and implemented in both private and academic environments, has proved a robust solution for shared facilities and

  18. Biophysical mimicry of lung surfactant protein B by random nylon-3 copolymers.

    PubMed

    Dohm, Michelle T; Mowery, Brendan P; Czyzewski, Ann M; Stahl, Shannon S; Gellman, Samuel H; Barron, Annelise E

    2010-06-16

    Non-natural oligomers have recently shown promise as functional analogues of lung surfactant proteins B and C (SP-B and SP-C), two helical and amphiphilic proteins that are critical for normal respiration. The generation of non-natural mimics of SP-B and SP-C has previously been restricted to step-by-step, sequence-specific synthesis, which results in discrete oligomers that are intended to manifest specific structural attributes. Here we present an alternative approach to SP-B mimicry that is based on sequence-random copolymers containing cationic and lipophilic subunits. These materials, members of the nylon-3 family, are prepared by ring-opening polymerization of beta-lactams. The best of the nylon-3 polymers display promising in vitro surfactant activities in a mixed lipid film. Pulsating bubble surfactometry data indicate that films containing the most surface-active polymers attain adsorptive and dynamic-cycling properties that surpass those of discrete peptides intended to mimic SP-B. Attachment of an N-terminal octadecanoyl unit to the nylon-3 copolymers, inspired by the post-translational modifications found in SP-C, affords further improvements by reducing the percent surface area compression to reach low minimum surface tension. Cytotoxic effects of the copolymers are diminished relative to that of an SP-B-derived peptide and a peptoid-based mimic. The current study provides evidence that sequence-random copolymers can mimic the in vitro surface-active behavior of lung surfactant proteins in a mixed lipid film. These findings raise the possibility that random copolymers might be useful for developing a lung surfactant replacement, which is an attractive prospect given that such polymers are easier to prepare than are sequence-specific oligomers.

  19. A combined mode fatigue model for glass reinforced nylon as applied to molded engine cooling fans

    SciTech Connect

    Smith, J.D.; Bennet, M.L.

    1985-01-01

    The use of glass reinforced nylon in fatigue inducing environments calls for a new method of stress analysis. With an engine cooling fan, both mean and vibratory stresses need to be examined. Speed cycling can cause tensile fatigue, while vibration can cause flexural fatigue. Since tensile and flexural stresses exist in the fan simultaneously, a combined mode fatigue model is needed. The proposed model is based on high cycle flexural and tensile fatigue strengths, and tensile strength. It relates measurable strain to stress using temperature dependent flexural and tensile moduli, and treats underhood temperature and desired product life as variables.

  20. 3D printing of weft knitted textile based structures by selective laser sintering of nylon powder

    NASA Astrophysics Data System (ADS)

    Beecroft, M.

    2016-07-01

    3D printing is a form of additive manufacturing whereby the building up of layers of material creates objects. The selective laser sintering process (SLS) uses a laser beam to sinter powdered material to create objects. This paper builds upon previous research into 3D printed textile based material exploring the use of SLS using nylon powder to create flexible weft knitted structures. The results show the potential to print flexible textile based structures that exhibit the properties of traditional knitted textile structures along with the mechanical properties of the material used, whilst describing the challenges regarding fineness of printing resolution. The conclusion highlights the potential future development and application of such pieces.

  1. Research on the melt impregnation of continuous carbon fiber reinforced nylon 66 composites

    NASA Astrophysics Data System (ADS)

    Jia, M. Y.; Li, C. X.; Xue, P.; Chen, K.; Chen, T. H.

    2016-07-01

    Impregnation mold of continuous carbon fiber reinforced thermoplastic composites was designed and built in the article. Based on the theory of fluid mechanics and Darcy's law, a model of the melt impregnation was also established. The influences of fiber bundle width and impregnation pins’ diameter on the impregnation degree were studied by numerical simulation. Continuous carbon fiber reinforced nylon 66 composites were prepared. The effects of coated angle and impregnation mold temperature on the mechanical properties of the composites were also described.The agreement between the experimental data and prediction by the model was found to be satisfactory.

  2. Shear-induced conformation change in α-crystalline nylon6

    SciTech Connect

    Arabnejad, Saeid; Manzhos, Sergei; Shim, V. P. W.; He, Chaobin

    2014-12-01

    A study of shear deformation of α-crystalline nylon6 is undertaken, using dispersion-corrected density functional theory. The shear stress-strain relationship and shear strength for interlayer shear deformation are computed. A conformation change induced by shear is identified along twinning deformation, whereby the conformation of chains, specifically the location of non-H-bonded hydrogen atoms, changes continuously. This paves a way for the modulation of properties of this group of materials by small shear deformation, if the non-H-bonded hydrogens are chemically substituted to form non-equivalent conformations when deformed.

  3. Application of pervaporation and vapor permeation processes to separate aqueous ethanol solution through chemically modified Nylon 4 membranes

    SciTech Connect

    Wang, Y.H.; Teng, M.Y.; Lee, K.R.; Wang, D.M.; Lai, J.Y.

    1998-08-01

    The pervaporation performance of a Nylon 4 membrane, chemically grafted by N,N-dimethylaminoethyl methacrylate (DMAEM), DMAEM-g-N4, was studied by measurement of the permeation ratio and the pervaporation separation index. It was found that the water permselectivity and permeation rate for the chemically modified Nylon 4 membrane were higher than those of the unmodified Nylon 4 membrane. Optimum pervaporation results, a separation factor of 28.3, and a permeation rate of 439 g/m{sup 2}{center_dot}h, were obtained when the degree of grafting was 12.7%. It was also found that all the permeation ratios at low temperature were less than unity. In addition, compared with pervaporation, vapor permeation effectively increases the permselectivity of water.

  4. Using nylon strips to dispense mosquito attractants for sampling the malaria vector Anopheles gambiae s.s.

    PubMed

    Okumu, F; Biswaro, L; Mbeleyela, E; Killeen, G F; Mukabana, R; Moore, S J

    2010-03-01

    Synthetic versions of human derived kairomones can be used as baits when trapping host seeking mosquitoes. The effectiveness of these lures depends not only on their attractiveness to the mosquitoes but also on the medium from which they are dispensed. We report on the development and evaluation of nylon strips as a method of dispensing odorants attractive to the malaria vector, Anopheles gambiae s.s. (Giles). When a synthetic blend of attractants was dispensed using this method, significantly more mosquitoes were trapped than when two previous methods, open glass vials or low density polyethylene sachets were used. We conclude that the nylon strips are suitable for dispensing odorants in mosquito trapping operations and can be adopted for use in rural and remote areas. The nylon material required is cheap and widely available and the strips can be prepared without specialized equipment or electricity.

  5. C-terminal functionalization of nylon-3 polymers: effects of C-terminal groups on antibacterial and hemolytic activities.

    PubMed

    Zhang, Jihua; Markiewicz, Matthew J; Mowery, Brendan P; Weisblum, Bernard; Stahl, Shannon S; Gellman, Samuel H

    2012-02-13

    Nylon-3 polymers contain β-amino-acid-derived subunits and can be viewed as higher homologues of poly(α-amino acids). This structural relationship raises the possibility that nylon-3 polymers offer a platform for development of new materials with a variety of biological activities, a prospect that has recently begun to receive experimental support. Nylon-3 homo- and copolymers can be prepared via anionic ring-opening polymerization of β-lactams, and use of an N-acyl-β-lactam as coinitiator in the polymerization reaction allows placement of a specific functional group, borne by the N-acyl-β-lactam, at the N-terminus of each polymer chain. Controlling the unit at the C-termini of nylon-3 polymer chains, however, has been problematic. Here we describe a strategy for specifying C-terminal functionality that is based on the polymerization mechanism. After the anionic ring-opening polymerization is complete, we introduce a new β-lactam, approximately 1 equiv relative to the expected number of polymer chains. Because the polymer chains bear a reactive imide group at their C-termini, this new β-lactam should become attached at this position. If the terminating β-lactam bears a distinctive functional group, that functionality should be affixed to most or all C-termini in the reaction mixture. We use the new technique to compare the impact of N- and C-terminal placement of a critical hydrophobic fragment on the biological activity profile of nylon-3 copolymers. The synthetic advance described here should prove to be generally useful for tailoring the properties of nylon-3 materials.

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

    PubMed Central

    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

  7. Barbed versus conventional 2-layer continuous running sutures for laparoscopic vaginal cuff closure

    PubMed Central

    Kim, Jin Hwi; Byun, Seung Won; Song, Jae Yeon; Kim, Yeon Hee; Lee, Hee Joong; Park, Tae Chul; Lee, Keun Ho; Hur, Soo Young; Park, Jong Sup; Lee, Sung Jong

    2016-01-01

    Abstract We compared results using unidirectional barbed sutures and conventional sutures for vaginal cuff closure during total laparoscopic hysterectomy (TLH).The electronic medical records and surgical videos of 170 patients who underwent TLH between January 2013 and March 2015 at Uijeong-bu St. Mary's Hospital of Catholic University of Korea were reviewed. Vaginal cuffs were closed using the 2-layer continuous running technique with unidirectional barbed sutures (V-Loc; Covidien, Mansfield, MA) in 64 patients and with polycolic acid Vicryl; Ethicon, Somerville, NJ sutures in 106 patients. Procedure time, clinical characteristics, and postoperative complications were compared between the 2 study groups. There were no differences in clinical characteristics (age, body mass index, and demographic data) between groups. The mean suturing time was significantly reduced in the barbed group (7.2 vs 12.2 minutes; P < 0.001), although the mean number of stitches was greater than in the Vicryl group (14.1 vs 12.3, P < 0.001). Perioperative complications, including episodes of vaginal bleeding, vaginal cuff cellulitis, and postoperative fever, did not differ between groups. There were no instances of vaginal cuff dehiscence in either group. Unidirectional barbed sutures can be used safely to reduce procedure time and surgical difficulty relative to conventional sutures in laparoscopic vaginal cuff closure. PMID:27684850

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

    PubMed

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

    2014-09-01

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

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

    PubMed

    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.

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

    PubMed Central

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

    2014-01-01

    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. PMID:25511173

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

    PubMed Central

    Saied, Alireza; Shekaari, Majid Asadi; Sadeghifar, Amirreza; Karbalaeikhani, Ali

    2015-01-01

    Background: The standard method for repair of an injured peripheal nerve is epineural repair with separate sutures. Herein we describe a method in which the nerve is sutured with continous sutures. In fact this method has not been utilized for nerve repair previously and our purpose was to compare it to the standard method. If it proved to be successful it would replace the standard method in certain circumstances. Methods: The proposal of the clinical trial was given a reference number form the ethics comitee. 25 dogs in which the scaitic nerve was cut by a sharp blade under genaeral anesthesia were divided randomly into three groups: control (5 dogs), repair of sciatic nerve with simple sutures (10) and repair with continous sutures (10). In the control group the nerve was not repaired at all. After 6 weeks the dogs were killed and the nerve was studied by light and electronic microscopes. The amount of consumed suture material, time of repair, myelin thickness and axon diiameter were examined. Ultrastructural studies were performed to assess degeneration and regeneration findings. Results: Time of repair and the amount of consumed suture material were significantly lower in the continous group (P<0.001). No difference was found with regard to light microscopy findings and regeneration was confirmed by electron microscopy in the continous group. Conclusion: The method described in the present study, provided a result similar to the standard method. Though undobtfully it has some limitations, can replace the standard method in many circumstances. PMID:26550589

  12. Synthesis of Ag/CNT hybrid nanoparticles and fabrication of their nylon-6 polymer nanocomposite fibers for antimicrobial applications.

    PubMed

    Rangari, Vijaya K; Mohammad, Ghouse M; Jeelani, Shaik; Hundley, Angel; Vig, Komal; Singh, Shree Ram; Pillai, Shreekumar

    2010-03-05

    Ag-coated CNTs hybrid nanoparticles (Ag/CNTs) were prepared by ultrasonic irradiation of dimethylformamide (DMF) and silver (I) acetate precursors in the presence of CNTs. The morphology of Ag/CNTs was characterized using x-ray diffraction and transmission electron microscopy (TEM) techniques. The Nylon-6 powder and 1 wt% Ag/CNTs mixture was dispersed uniformly using a noncontact spinning technique. The dried mixture was melted in a single screw extrusion machine and then extruded through an orifice. Extruded filaments were later stretched and stabilized by sequentially passing them through a set of tension adjusters and a secondary heater. The Nylon-6/Ag/CNT hybrid polymer nanocomposite (HPNC) fibers, which were of approximately 80 microm size, were tested for their tensile properties. The failure stress and modulus of the extruded HPNC fibers (doped with 1% Ag/CNTs) was about 72.19 % and 342.62% higher than the neat extruded Nylon-6 fiber, respectively. DSC results indicated an increase in the thermal stability and crystallization for HPNC fibers. The antibacterial activity of the Ag-coated CNTs, commercial Ag, neat Nylon-6 and plain CNTs were evaluated. Ag-coated CNTs at 25 microg demonstrated good antimicrobial activity against four common bacterial pathogens as tested by the Kirby-Bauer assay. The mean diameters of the zones of inhibition were 27.9 +/- 6.72 mm, 19.4 +/- 3.64 mm, 21.9 +/- 4.33 mm, and 24.1 +/- 4.14 mm, respectively, for Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Salmonella enterica serovar Typhimurium. By comparison, those obtained using the broad spectrum antibiotic amoxicillin-clavulanic acid were 37.7 +/- 2.13 mm, 28.6 +/- 4.27 mm, 22.6 +/- 1.27 mm, and 27.0 +/- 1.41 mm, respectively, for the same strains. The zones of inhibition obtained for Nylon-6 Ag-coated CNT powder at 25 microg were also high, ranging from 15.2 to 25.3 mm in contrast to commercial silver or neat Nylon-6, which did not inhibit the bacterial

  13. The Effect of Anhydrous Ammonia on the Crystalline State Deformation of Nylons 6 and 6,6.

    DTIC Science & Technology

    1981-09-14

    for Public Release; Distribution Unlimited !1 82t 01 11 057 THE EFFECT OF ANHYDROUS AMONIA ON THE CRYSTALLINE STATE DEFORMATION OF NYLONS 6 AND 6,6 by...7 AD-A109 62 MASSACHUSETTS UWIV AMHERST DEPT OF POLYMER SCIENCE -ETC FIG 11/9 THE EFFECT OF ANHYDROUS AMMONIA ON THE CRYSTALLINE STATE DFORN-ETC(U...REPORT NO. 15 "THE EFFECT OF ANHYDROUS AMMONIA ON THE CRYSTALLINE STATE DEFORMATION OF NYLONS 6 AND 6,6" by Tetsuo Kanamoto, Anagnostis E. Zachariades

  14. Synthesis of Ag/CNT hybrid nanoparticles and fabrication of their Nylon-6 polymer nanocomposite fibers for antimicrobial applications

    NASA Astrophysics Data System (ADS)

    Rangari, Vijaya K.; Mohammad, Ghouse M.; Jeelani, Shaik; Hundley, Angel; Vig, Komal; Ram Singh, Shree; Pillai, Shreekumar

    2010-03-01

    Ag-coated CNTs hybrid nanoparticles (Ag/CNTs) were prepared by ultrasonic irradiation of dimethylformamide (DMF) and silver (I) acetate precursors in the presence of CNTs. The morphology of Ag/CNTs was characterized using x-ray diffraction and transmission electron microscopy (TEM) techniques. The Nylon-6 powder and 1 wt% Ag/CNTs mixture was dispersed uniformly using a noncontact spinning technique. The dried mixture was melted in a single screw extrusion machine and then extruded through an orifice. Extruded filaments were later stretched and stabilized by sequentially passing them through a set of tension adjusters and a secondary heater. The Nylon-6/Ag/CNT hybrid polymer nanocomposite (HPNC) fibers, which were of ~ 80 µm size, were tested for their tensile properties. The failure stress and modulus of the extruded HPNC fibers (doped with 1% Ag/CNTs) was about 72.19 % and 342.62% higher than the neat extruded Nylon-6 fiber, respectively. DSC results indicated an increase in the thermal stability and crystallization for HPNC fibers. The antibacterial activity of the Ag-coated CNTs, commercial Ag, neat Nylon-6 and plain CNTs were evaluated. Ag-coated CNTs at 25 µg demonstrated good antimicrobial activity against four common bacterial pathogens as tested by the Kirby-Bauer assay. The mean diameters of the zones of inhibition were 27.9 ± 6.72 mm, 19.4 ± 3.64 mm, 21.9 ± 4.33 mm, and 24.1 ± 4.14 mm, respectively, for Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Salmonella enterica serovar Typhimurium. By comparison, those obtained using the broad spectrum antibiotic amoxicillin-clavulanic acid were 37.7 ± 2.13 mm, 28.6 ± 4.27 mm, 22.6 ± 1.27 mm, and 27.0 ± 1.41 mm, respectively, for the same strains. The zones of inhibition obtained for Nylon-6 Ag-coated CNT powder at 25 µg were also high, ranging from 15.2 to 25.3 mm in contrast to commercial silver or neat Nylon-6, which did not inhibit the bacterial strains tested. Further, the

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

    PubMed Central

    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

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

    PubMed

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

    2014-02-01

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

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

    PubMed

    Boyar, Ibrahim Hakan; Boynukalın, Fazilet Kübra; Boyar, Nuray; Vural, Mehmet

    2011-01-01

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

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

    PubMed

    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).

  19. A novel approach for application of nylon membranes in the biosensing domain

    NASA Astrophysics Data System (ADS)

    Farahmand, Elham; Ibrahim, Fatimah; Hosseini, Samira; Rothan, Hussin A.; Yusof, Rohana; Koole, Leo H.; Djordjevic, Ivan

    2015-10-01

    In this paper we report the polymer-coated microporous nylon membranes and their application as platforms for protein immobilization and subsequent detection of the dengue virus (DV) in blood serum. Protein recognition experiments were performed with enzyme-linked immunosorbent assay (ELISA). The polymers used for coatings were synthesized by free-radical polymerization reaction between methyl methacrylate (MMA) and methacrylic acid (MAA) in different concentrations. The MAA monomer has carefully been chosen to generate polymers with pendant carboxyl (-COOH) groups, which also exist on polymer surfaces. A high degree of control over surface-exposed -COOH groups has been achieved through variation of monomers concentration in polymerization reaction. The general aspect of this work relies on the dengue antibody (Ab) immobilization on surface -COOH groups via physical attachment or covalent immobilization. Prior to Ab immobilization and ELISA experiment, polymer-coated nylon samples were analyzed in detail for their physical properties by atomic force microscopy (AFM), scanning electron microscopy (SEM), and water-in-air contact angle (WCA) measurements. Membranes were further analyzed by Fourier transform infrared spectroscopy (FTIR) in order to establish the relationship between wettability, porosity, and surface roughness with chemical composition and concentration of -COOH groups on the coating's surface. Optimized coatings have shown high sensitivity towards dengue Ab molecules, revealing fundamental aspect of polymer-protein interfaces as a function of surface -COOH groups' concentration.

  20. Position control of fishing line artificial muscles (coiled polymer actuators) from nylon thread

    NASA Astrophysics Data System (ADS)

    Arakawa, Takeshi; Takagi, Kentaro; Tahara, Kenji; Asaka, Kinji

    2016-04-01

    Recently, fishing line artificial muscle has been developed and is paid much attention due to the properties such as large contraction, light weight and extremely low cost. Typical fishing line artificial muscle is made from Nylon thread and made by just twisting the polymer. In this paper, because of the structure of the actuator, such actuators may be named as coiled polymer actuators (CPAs). In this paper, a CPA is fabricated from commercial Nylon fishing line and Ni-Cr alloy (Nichrome) wire is wound around it. The CPA contracts by the Joule heat generated by applied voltage to the Nichrome wire. For designing the control system, a simple model is proposed. According to the physical principle of the actuator, two first-order transfer functions are introduced to represent the actuator model. One is a system from the input power to the temperature and the other is a system from the temperature to the deformation. From the system identification result, it is shown that the dominant dynamics is the system from the input power to the temperature. Using the developed model, position control of the voltage-driven CPA is discussed. Firstly, the static nonlinearity from the voltage to the power is eliminated. Then, a 2-DOF PID controller which includes an inversion-based feed forward controller and a PID controller are designed. In order to demonstrate the proposed controller, experimental verification is shown.

  1. Ion beam modification of CR-39 (DOP) and polyamide nylon-6 polymers

    NASA Astrophysics Data System (ADS)

    Kumar, Rajesh; Prasad, Rajendra; Vijay, Y. K.; Acharya, N. K.; Verma, K. C.; De, Udayan

    2003-12-01

    Swift heavy ions interact predominantly through inelastic scattering while traversing any polymeric medium and produce excited/ionized atoms. This results into the modification of physical and chemical response of the polymer. CR-39 (DOP) and polyamide nylon-6 polymer samples were irradiated with 70 MeV C 5+ ion beam to the fluences of 10 11, 10 12 and 10 13 ions cm -2. Modifications due to irradiation were studied using Fourier transform infra red (FTIR) spectroscopic and X-ray diffraction (XRD) technique. Considerable deformation has been observed in both the polymers at the fluence of 10 12 and 10 13 ions cm -2. XRD analyses show slight shift of peak position and significant changes in peak width and intensity. Particle size or grain size, calculated by applying Scherrer formula, indicates measurable changes in particle size in the irradiated samples. XRD peaks at d-values of 4.335 Å and 3.838 Å for the virgin polyamide nylon-6 gradually change with increasing fluence into one broad peak. Some difference in the irradiation effect in these two different polymers has been observed.

  2. Rigid Nylon Foil-Anchored Polytetrafluoroetyhlene (Gor-Tex) Sheet Stenting For Conjunctival Fornix Reconstruction

    PubMed Central

    Demirci, Hakan; Elner, Susan G.; Elner, Victor M.

    2011-01-01

    Purpose To describe a surgical technique that deepens foreshortened conjunctival fornices by providing a scaffold for epithelialization that opposes contractile forces during wound healing. Design Retrospective interventional case series Participants Seventeen patients with anophthalmic sockets containing foreshortened conjunctival fornices Methods Conjunctival fornices was reconstructed with stents of expanded polytetrafluoroethylene (e-PTFE) sheet draped over rigid, 0.8 mm thick nylon strips that were anchored to the orbital rim. Preoperative and postoperativesymptoms, prosthesis retention, fornix depth, and lagophthalmos were assessed. Main Outcome Measure Prosthesis retention, fornix depth, and lagophthalmos Results All 17 patients had preoperative inability to retain their prosthesis. After postoperative follow-up of 47 ± 43 months, retention was improved in all patients and was entirely satisfactory in 15 (88%) patients. After reconstruction, the repaired fornix was deep in 7 (41%) patients, adequate to retain a prosthesis in 9 (53%) patients, and shallow in 1 (6%) patient. Lagophthalmos improved in 15 (88%) patients and remained unchanged in 2 (12%) patients. Superior fornix was reconstructed concurrently with the inferior fornix in 6 patients. In these patients, the superior fornix improved to deep (3 patients; 50%) or adequate (2; 33%). In 1 (17%) patient, it remained shallow. Conclusion Rigid, nylon-foil anchored e-PTFE stenting opposes postoperative contracture, improving prosthesis retention, and lagophthalmos. It does not require an additional surgical site for graft harvesting. PMID:20691479

  3. Selective Carbon Fiber Reinforced Nylon 66 Spur Gears: Development and Performance

    NASA Astrophysics Data System (ADS)

    Senthilvelan, S.; Gnanamoorthy, R.

    2006-01-01

    A new design methodology is developed to mold the polymer spur gears with high strength fiber reinforcement only in the highly stressed region. High performance high cost short carbon fiber reinforced Nylon 66 is used in the highly stressed tooth region and low cost unreinforced Nylon 66 is used in the hub region. Two different geometries, circular and spline shaped hubs were used for developing the selective reinforced gears by multi-shot injection-molding process. Joint strength of the selectively reinforced gear was estimated using shear tests. Clear hub and tooth region separation without any distortion was observed in joint shear tests. A molten material due to fusion bonding was observed at the interfaces. The joint strength was also evaluated by conducting gear fatigue tests using a power absorption test rig at various torque levels and at a constant gear rotational speed. Monolithic reinforced gear and selective reinforced gears with spline hub exhibited similar fatigue behavior. The failure mode depends upon the test torque level. The selective reinforced gears with circular hub showed joint failures at high-test torque levels. Absence of mechanical interlocking feature in the circular hub geometry contributes to the joint failure. Thermal bond, part interference and mechanical interlocking feature provide sufficient joint strength to the selective reinforced gear with spline hub.

  4. Fabrication of porous calcite using chopped nylon fiber and its evaluation using rats.

    PubMed

    Ishikawa, Kunio; Tram, Nguyen Xuan Thanh; Tsuru, Kanji; Toita, Riki

    2015-02-01

    Although porous calcite has attracted attention as bone substitutes, limited studies have been made so far. In the present study, porous calcite block was fabricated by introducing chopped nylon fiber as porogen. Ca(OH)2 powder containing 10 wt% chopped nylon fiber was compacted at 150 MPa, and sintered to burn out the fiber and to carbonate the Ca(OH)2 under stream of 1:2 O2-CO2. Sintering of Ca(OH)2 at 750 °C or lower temperature resulted in incomplete burning out of the fiber whereas sintering at 800 °C or higher temperature resulted in the formation of CaO due to the thermal decomposition of Ca(OH)2. However, sintering at 770 °C resulted in complete burning out of the fiber and complete carbonation of Ca(OH)2 to calcite without forming CaO. Macro- and micro-porosities of the porous calcite were approximately 23 and 16%, respectively. Diameter of the macropores was approximately 100 μm which is suitable for bone tissue penetration. Porous calcite block fabricated by this method exhibited good tissue response when implanted in the bone defect in femur of 12-weeks-old rat. Four weeks after implantation, bone bonded on the surface of calcite. Furthermore, bone tissue penetrated interior to the macropore at 8 weeks. These results demonstrated the good potential value of porous calcite as artificial bone substitutes.

  5. Atrazine adsorption removal with nylon6/polypyrrole core-shell nanofibers mat: possible mechanism and characteristics

    NASA Astrophysics Data System (ADS)

    Yang, Bi-Yi; Cao, Yang; Qi, Fei-Fei; Li, Xiao-Qing; Xu, Qian

    2015-05-01

    A functionalized nylon6/polypyrrole core-shell nanofibers mat (PA6/PPy NFM) was prepared via situ polymerization on nylon6 electrospun nanofibers mat (PA6 NFM) template and used as an adsorbent to remove atrazine from aqueous solutions. The core-shell structure of PA6/PPy NFM can be clearly proved under scanning electron microscope (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The effects of initial solution pH and ionic strength, as well as the comparison of the adsorption capacity of functionalized (PA6/PPy NFM) and non-functionalized (PA6 NFM) adsorbent, were examined to reveal the possible adsorption mechanism. The results indicated that π-π interaction and electrostatic interaction should play a key role in the adsorption process. The kinetics and thermodynamics studies also further elucidated the detailed adsorption characteristics of atrazine removal by PA6/PPy NFM. The adsorption of atrazine could be well described by the pseudo-second-order equation. The adsorption equilibrium data was well fitted with the Freundlich isotherm model with a maximum adsorption capacity value of 14.8 mg/g. In addition, the increase of adsorption rate caused by a temperature increase could be felicitously explained by the endothermic reaction. The desorption results showed that the adsorption capacity remained almost unchanged after six adsorption/desorption cycles. These results suggest that PA6/PPy NFM could be employed as an efficient adsorbent for removing atrazine from contaminated water sources.

  6. Detection by cationized /sup 125/I-cytochrome C of proteoglycans (PG) transferred to nylon

    SciTech Connect

    Heimer, R.; Sampson, P.M.; Fishman, A.P.

    1986-05-01

    Cytochrome c, labeled with /sup 125/I, has been used by us for staining glycosaminoglycans (GAG) separated by electrophoresis on cellulose acetate strips. As GAG between 1-10 ng could be quantified by autoradiography and densitometry, the reagent is approximately 100-fold more sensitive than currently used non-radiolabeled stains. The authors extend now the use of radiolabeled cytochrome c to the quantification of PG transblotted to solid supports subsequent to separation on polyacrylamine slab gels. Dot blotting used for exploring optimal conditions for detecting PG indicated that because of low background positively charged Nylon 66 was superior to nitrocellulose. Increasing the positive charge of the staining reagent by cationization decreased background radiation even further so that 1 ng PG could be seen readily after 5 hrs of autoradiography. Use of cationized /sup 125/I-cytochrome c has been made in detecting PG of bovine fetal epiphyseal cartilage (> 1 x 10/sup 6/ D) and PG of bovine aorta (0.25 x 10/sup 6/ D) following slab gel electrophoresis and electrophoretic transblotting. With effective electrophoretic transfer of the PG to positively charged Nylon 66, the sensitivity of detection of the two PG was increased at least 100-fold over that observed when the gels were stained with toluidine blue, the method in current use.

  7. Ab initio calculation of the crystalline structure and IR spectrum of polymers: nylon 6 polymorphs.

    PubMed

    Quarti, Claudio; Milani, Alberto; Civalleri, Bartolomeo; Orlando, Roberto; Castiglioni, Chiara

    2012-07-19

    State-of-the-art computational methods in solid-state chemistry were applied to predict the structural and spectroscopic properties of the α and γ crystalline polymorphs of nylon 6. Density functional theory calculations augmented with an empirical dispersion correction (DFT-D) were used for the optimization of the two different crystal structures and of the isolated chains, characterized by a different regular conformation and described as one-dimensional infinite chains. The structural parameters of both crystalline polymorphs were correctly predicted, and new insight into the interplay of conformational effects, hydrogen bonding, and van der Waals interactions in affecting the properties of the crystal structures of polyamides was obtained. The calculated infrared spectra were compared to experimental data; based on computed vibrational eigenvectors, assignment of the infrared absorptions of the two nylon 6 polymorphs was carried out and critically analyzed in light of previous investigations. On the basis of a comparison of the computed and experimental IR spectra, a set of marker bands was identified and proposed as a tool for detecting and quantifying the presence of a given polymorph in a real sample: several marker bands employed in the past were confirmed, whereas some of the previous assignments are criticized. In addition, some new marker bands are proposed. The results obtained demonstrate that accurate computational techniques are now affordable for polymers characterization, opening the way to several applications of ab initio modeling to the study of many families of polymeric materials.

  8. A simple and robust method for preparation of cDNA nylon microarrays.

    PubMed

    Yamakawa, Hisashi; Yokoyama, Satoru; Hirano, Takeo; Kitamura, Hiroshi; Ohara, Osamu

    2004-10-31

    DNA array technology has made remarkable progress in recent years and has become an indispensable tool in molecular biology research. However, preparing high-quality custom-made DNA arrays at a reasonable cost is still an important concern because we cannot abandon the use of DNA array systems designed for specific purposes. To address these problems, we here report the use of rolling circle amplification products of cDNA plasmids dissolved in 80% formamide as DNA probes immobilized on a nylon membrane. First, because formamide is practically non-volatile under ambient conditions and nucleic acids are easily dissolved in it, the use of formamide as a DNA solvent ensures that the DNA concentration of the solution will not change during arraying, which often takes several hours to a day depending on the number of DNA spots and arrays to produce. Secondly, the use of rolling circle amplification technology greatly reduced the labor needed to prepare the spotted DNA. The results in this study demonstrate that the introduction of these two modifications in preparation of nylon DNA array greatly improved its quality.

  9. Shape memory alloy fixator system for suturing tissue in minimal access surgery.

    PubMed

    Xu, W; Frank, T G; Stockham, G; Cuschieri, A

    1999-01-01

    A new technique for suturing human tissue is described in which tissue closure is achieved by means of small fixators made from shape memory alloy. The aim of the development is to provide an alternative to thread suturing in minimal access surgery, which is quicker and requires less skill to achieve the required suturing quality. The design of the fixators is described in terms of the thermal shape recovery of shape memory alloy and a novel form of finite element analysis, which uses a nonlinear elastic element for the material property. Thermal analysis of the fixators and surrounding tissue is used to predict the temperature distribution during and after the application of electric current heating. This was checked in an in vitro experiment, which confirmed that deployment caused no detectable collateral damage to surrounding tissue. In vivo animal studies on the use of the shape memory alloy fixator for suturing tissue are ongoing to establish safety and healing effects.

  10. Synthesis and characterization of aliphatic polyurethane fiber: a potential suture material.

    PubMed

    Ray, A R; Bhowmick, A

    1991-10-01

    Polyurethane fibers were synthesized and characterized by IR, 1H NMR, DSC, and GPC. Their properties as fiber were compared with commercially available sutures of polypropylene, polyamide, polyester, and silk.

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

    PubMed Central

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

    2014-01-01

    Craniosynostosis is a pathologic condition which is characterized by the premature fusion of cranial sutures. It may occur alone or in association with other anomalies making up various syndromes. Crouzon syndrome is the most common craniosynostosis syndrome. Bicoronal sutures fusion is most commonly involved in Crouzon syndrome. There have only been a handful of cases of squamosal suture synostosis described in the surgery literature with the few ones described in Crouzon syndrome associated 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. PMID:25071892

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

    PubMed Central

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

    2016-01-01

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

  13. Timing of cranial suture closure in placental mammals: phylogenetic patterns, intraspecific variation, and comparison with marsupials.

    PubMed

    Rager, Lisa; Hautier, Lionel; Forasiepi, Analía; Goswami, Anjali; Sánchez-Villagra, Marcelo R

    2014-02-01

    Used as markers of postnatal growth closure sequences of 22 ectocranial sutures and synchondroses were recorded in a sample of 1161 skulls belonging to 38 species from all major placental clades: Afrotheria, Xenarthra, Laurasiatheria and Euarchontoglires (Boreoeutheria). The maximum closure level, which is not significantly correlated to body mass, is higher in Afrotheria and Xenarthra than in Boreoeutheria. Only the basioccipito-basisphenoid and the basioccipito-exoccipital synchondroses close in all species sampled, the supraoccipito-exoccipital and the inter-parietal sutures do in most species. Parsimov retrieved more heterochronic shifts for Afrotheria and Xenarthra than for Boreoeutheria. The amount of intraspecific variation differs among the species sampled being high among xenarthran species and low among afrotherians. Specimens (162) representing 12 marsupial genera were also analysed. Placentals exhibit a larger number of suture closures than marsupials and in both groups the sutures at the base of the skull are the first to fuse starting with the basioccipito-exoccipital.

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

    PubMed

    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.

  15. Modified Quilting Sutures: ANew Technique for Hematoma and Abscess of Nasal Septum.

    PubMed

    Ahmed, Shoaib; Ashfaq, Muhammed; Shabbir, Asad

    2016-06-01

    This study aimed to analyze the results of a modified continuous quilting sutures technique in a series of patients presenting with hematoma and/or abscess of nasal septum (HANS). Only patients with a confirmed diagnosis of HANS without co-morbid conditions (which could predispose to a bleeding tendency), were selected. Following incision and drainage, nasal septal flaps were coapted by applying continuous quilting sutures only. The success rate of this technique in terms of recurrence requiring re-exploration and drainage was 100%. Quilting sutures were generally well tolerated with few complaints. Saddle deformity was the most obvious complication of HANS, seen with septal abscess. Quilting sutures can be considered as an alternative treatment option for HANS. The modified technique employed in this study demonstrated impressive results and avoided the morbidity of nasal packing with fewer complications.

  16. Thoracoscopic esophageal repair with barbed suture material in a case of Boerhaave’s syndrome

    PubMed Central

    Sato, Chiaki; Sakurai, Tadashi; Kamiya, Kurodo; Kamei, Takashi; Ohuchi, Noriaki

    2016-01-01

    A 53-year-old man was referred to our hospital with Boerhaave’s syndrome. Thirty hours after onset, a left thoracoscopic operation was performed, with carbon dioxide pneumothorax and the patient in right semi-prone position. The thoracic cavity was copiously irrigated with physiological saline and a 4-cm longitudinal rupture was identified on the left side of the lower esophagus. The esophageal injury was repaired in 2 layers by using barbed absorbable suture material. The patient was allowed oral feeds after contrast esophagography confirmed the absence of contrast leak at the sutured site on postoperative day 7, and discharged by day 28. Suturing of the ruptured esophagus under thoracoscopic guidance is considered to be difficult and requires expertise. This case report demonstrates that the use of a barbed suture material simplifies thoracoscopic esophageal repair and also highlights the importance of pneumothorax and patient position in improving access to the esophagus. PMID:28149585

  17. Effects of pressure, oxygen concentration, and forced convection on flame spread rate of Plexiglas, Nylon and Teflon

    NASA Technical Reports Server (NTRS)

    Notardonato, J. J.; Burkhardt, L. A.; Cochran, T. H.

    1974-01-01

    Experiments were conducted in which the burning of cylindrical materials in a flowing oxidant stream was studied. Plexiglas, Nylon, and Teflon fuel specimens were oriented such that the flames spread along the surface in a direction opposed to flowing gas. Correlations of flame spread rate were obtained that were power law relations in terms of pressure, oxygen concentration, and gas velocity.

  18. The Cyclohexanol Cycle and Synthesis of Nylon 6,6: Green Chemistry in the Undergraduate Organic Laboratory

    ERIC Educational Resources Information Center

    Dintzner, Matthew R.; Kinzie, Charles R.; Pulkrabek, Kimberly; Arena, Anthony F.

    2012-01-01

    A one-term synthesis project that incorporates many of the principles of green chemistry is presented for the undergraduate organic laboratory. In this multistep scheme of reactions, students react, recycle, and ultimately convert cyclohexanol to nylon 6,6. The individual reactions in the project employ environmentally friendly methodologies, and…

  19. A nylon membrane bag assay for determination of the effect of chemicals on soilborne plant pathogens in soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new nylon membrane bag assay was developed that can rapidly and effectively determine the impact of chemicals added to soil on soilborne plant pathogens for which there are no selective media or for which a selective medium is expensive or difficult to prepare. This assay consists of placing patho...

  20. The effects of the conditions of char formation on the physical properties of charred phenolic-nylon

    NASA Technical Reports Server (NTRS)

    Smyly, E. D.; Pears, C. D.

    1972-01-01

    A study was made of the effects of the conditions of char formation on the physical properties of charred phenolic nylon of 0.577 gm/cu cm density. It was found that the thermal conductivity and several of the monitors correlate well with degradation conditions. The monitors included electrical resistivity, sonic velocity, porosity, lattice spacing and crystallite size.

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

    PubMed

    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.

  2. Antimicrobial-coated sutures to decrease surgical site infections: a systematic review and meta-analysis.

    PubMed

    Wu, X; Kubilay, N Z; Ren, J; Allegranzi, B; Bischoff, P; Zayed, B; Pittet, D; Li, J

    2017-01-01

    To investigate the effectiveness of antimicrobial-coated sutures compared with non-coated sutures in reducing surgical site infection (SSI) and develop recommendations for World Health Organization (WHO) SSI prevention guidelines. We searched Medline, Embase, Cinahl, Cochrane Central Register of Controlled Trials, and WHO Global Health from 1990-16/02/2015 with language restricted to English, Spanish, and French. Meta-analysis was performed with a random-effects model. Meta-regression analysis assessed whether the effect of antimicrobial coating changed according to the type of suture and surgery. Subgroup analyses were based on types of sutures. Quality of the retrieved evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation. Thirteen randomized controlled trials (RCTs) and five observational studies (OBSs) met the inclusion criteria. Antimicrobial sutures significantly reduced SSI risk (for RCTs: OR 0.72, 95 % CI 0.59-0.88, p = 0.001, I(2) = 14 %; for OBSs: OR 0.58, 95 % CI 0.40-0.83, p = 0.003, I(2) = 22 %). Only Vicryl Plus vs Vicryl revealed consistent results in favor of antimicrobial sutures (for seven RCTs: OR 0.62, 95 % CI 0.44-0.88, p = 0.007, I(2) = 3 %; for four OBSs: OR 0.58, 95 % CI 0.37-0.92, p = 0.02, I(2) = 41 %). The effect of antimicrobial coating was similar between different suture, wound, and procedure types. Quality of RCT evidence was moderate, and OBS evidence was very low quality. Triclosan-coated sutures may reduce SSI risk. However, the available evidence is of moderate/low quality, and many studies had conflicts of interest.

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

    PubMed

    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.

  4. Introducing a Favourite Tip Definition and Projection with Tripod Suture in Rhinoplasty

    PubMed Central

    Motamed, Sadrollah; Niazi, Feizollah; Moosavizadeh, Seyed Mehdi; Motaghedi, Babak; Tizmaghz, Adnan

    2017-01-01

    Introduction Surgical manipulation of the lower lateral cartilages of nasal tip could cause subtle but significant responses to the manipulation. The suture-techniques almost always offer a reliable and dramatic method of tip reshaping without a need to break or interrupt the alar rim strip or even adding tip graft. Aim The aim of this study was to describe and assess outcomes of a new suture technique in rhinoplasty by using cephalic dome septal rotation suture for better tip definition. Materials and Methods All consecutive women (62 women) who attended our centre with nasal tip drooping and some degree of columellar retraction, underwent this technique from January 2005 to September 2009. Their ages ranged from 17 to 32 years old. Fifty one primary open and 11 secondary open rhinoplasties were performed using the conventional techniques and then the new suture technique was applied before closing the incisions on each patient. Results The patients were followed-up from 22 to 72 months (mean = 52.3). The projection and rotation was satisfactory in all patients and the final results persisted with only minimal changes over time. Conclusion It is important to say that this new suture is different from ‘tip rotation suture’ that was described by Tebbets. Our suture maintains the favorite tip definition with slight dorsal tip inclination. Indeed, it causes a two-point definition as the columellar lobular angle and the supra tip break definition. In addition, long-term follow-up has shown that this new suture (i.e., cephalic dome-septal rotation suture) is able to maintain optimal position of the nasal tip projection and definition. PMID:28273999

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

    PubMed

    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).

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

    PubMed

    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.

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

    PubMed

    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.

  8. Comparison of viscoelastic properties of suture versus porcine mitral valve chordae tendineae.

    PubMed

    Cochran, R P; Kunzelman, K S

    1991-12-01

    Recent reports have advocated the use of polytetrafluoroethylene (PTFE) suture for replacement or reinforcement of ruptured or elongated mitral valve chordae tendineae. The mechanical properties of PTFE (Gore-Tex) and other sutures were determined and compared to those of porcine mitral valve chordae. The results were analyzed to assess how closely chordal mechanical function may be simulated by synthetic suture materials. Chordae tendineae and suture samples were tested in uniaxial tension using an INSTRON Model 1000 at strain rates of 5 and 10 mm/min. The stress (g/mm2) was plotted versus strain, and the elastic modulus determined as the slope of the curve. Chordae tendineae exhibited a nonlinear viscoelastic stress/strain behavior. The elastic modulus of both suture types tested was significantly higher than that of the chordae. However, the PTFE suture did exhibit some viscoelastic characteristics (hysteresis and creep) that begin to approach the chordal behavior. Chordal viscoelastic behavior results from the inherent composite structure (collagen, elastin, endothelium, water, and ground substance). As yet, no synthetic materials are able to imitate this behavior with the appropriate tensile strength and fatigue resistant characteristics. At present, PTFE appears to be the best synthetic alternative for chordal replacement, due to its limited viscoelastic capabilities. Nevertheless, the need to more nearly approximate the mechanical behavior of mitral valve chordae tendineae with synthetic material warrants further investigation.

  9. Subsurface geometry of the Siletz-Klamath suture in southwest Oregon from mangnetotelluric imaging

    NASA Astrophysics Data System (ADS)

    Box, S.; Bedrosian, P. A.

    2006-12-01

    Siletzia, a Paleocene to early Eocene basaltic seamount terrane, was sutured onto western North America in Eocene times and comprises the modern forearc basement throughout the Pacific Northwest. The suture zone is mostly obscured by the Cascades Arc. In southwest Oregon, however, it is preserved where previously accreted Mesozoic terranes in the Klamath Moutains overthrust Siletzia. The geometry of this suture at depth, however, is poorly constrained. In summer 2006, long-period (deep-crustal) and broadband (shallow-crustal) magnetotelluric (MT) data were collected along a 200-km profile stretching from the Pacific coast north of Coos Bay, OR to the California border south of Medford, OR, with an average site spacing of 4 km. South of the suture, the profile crosses Franciscan and Great Valley equivalents, arc lavas and sediments of the Western Klamath terrane, ophiolitic mélange of the Rattlesnake Creek terrane, and the Hayfork volcanic arc terrane, ending within the Condry Mountain Window. The data are in general agreement with the NW surface strike of the suture and the Klamath terranes. A smooth regularized two-dimensional inversion of the data resulted in a preliminary model extending to ~ 50 km depth which fits the data and is in accordance with observed surface geology. The imaged subsurface geometry of the Siletzia-Klamath suture is compared to previous potential-field modeling that suggested a thinning wedge of Silitzia has been thrust within the Klamath terranes.

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

    PubMed

    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.

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

    PubMed

    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.

  12. Identification and dynamics of a cryptic suture zone in tropical rainforest

    PubMed Central

    Moritz, C.; Hoskin, C.J.; MacKenzie, J.B.; Phillips, B.L.; Tonione, M.; Silva, N.; VanDerWal, J.; Williams, S.E.; Graham, C.H.

    2009-01-01

    Suture zones, shared regions of secondary contact between long-isolated lineages, are natural laboratories for studying divergence and speciation. For tropical rainforest, the existence of suture zones and their significance for speciation has been controversial. Using comparative phylogeographic evidence, we locate a morphologically cryptic suture zone in the Australian Wet Tropics rainforest. Fourteen out of 18 contacts involve morphologically cryptic phylogeographic lineages, with mtDNA sequence divergences ranging from 2 to 15 per cent. Contact zones are significantly clustered in a suture zone located between two major Quaternary refugia. Within this area, there is a trend for secondary contacts to occur in regions with low environmental suitability relative to both adjacent refugia and, by inference, the parental lineages. The extent and form of reproductive isolation among interacting lineages varies across species, ranging from random admixture to speciation, in one case via reinforcement. Comparative phylogeographic studies, combined with environmental analysis at a fine-scale and across varying climates, can generate new insights into suture zone formation and to diversification processes in species-rich tropical rainforests. As arenas for evolutionary experimentation, suture zones merit special attention for conservation. PMID:19203915

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

    PubMed Central

    Li, Wang; Zhang, Kaibin

    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. PMID:28078282

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

    PubMed Central

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

    2015-01-01

    Introduction There are many closure techniques available to cutaneous surgeons. One of them is the purse-string suture which is used to provide complete or partial closure of round skin defects. In our animal study; we closed skin defects with using subcuticular purse string suture technique by progressively cinching wound and we aim to more rapidly healing according to secondary healing. Methods After anaesthetize, we created a 4 cm diameter circular full thickness skin defect on dorsal area of rats. In group 1, subcuticular purse string suture was applied by using a nonabsorbable and monofilament suture and a sliding arthroscopic knot was applied to both ends. Arthroscopic suture was shift 1 cm forward every day. In group 2 skin defect was leaved open and daily dressing was made and in both group defect diameters were measured every day and noted. Results The skin defects were closed totally after 15 days in group 1 but in group 2 defects were reduced but still had a mean 1,5-cm diameter sircular defect. Conclusion Closing large circular wound with purse string suture and gradual tightening decreases the healing time and expand the skin tissue without using any tissue expander. PMID:26600915

  15. Polymer-inorganic core-shell nanofibers by electrospinning and atomic layer deposition: flexible nylon-ZnO core-shell nanofiber mats and their photocatalytic activity.

    PubMed

    Kayaci, Fatma; Ozgit-Akgun, Cagla; Donmez, Inci; Biyikli, Necmi; Uyar, Tamer

    2012-11-01

    Polymer-inorganic core-shell nanofibers were produced by two-step approach; electrospinning and atomic layer deposition (ALD). First, nylon 6,6 (polymeric core) nanofibers were obtained by electrospinning, and then zinc oxide (ZnO) (inorganic shell) with precise thickness control was deposited onto electrospun nylon 6,6 nanofibers using ALD technique. The bead-free and uniform nylon 6,6 nanofibers having different average fiber diameters (∼80, ∼240 and ∼650 nm) were achieved by using two different solvent systems and polymer concentrations. ZnO layer about 90 nm, having uniform thickness around the fiber structure, was successfully deposited onto the nylon 6,6 nanofibers. Because of the low deposition temperature utilized (200 °C), ALD process did not deform the polymeric fiber structure, and highly conformal ZnO layer with precise thickness and composition over a large scale were accomplished regardless of the differences in fiber diameters. ZnO shell layer was found to have a polycrystalline nature with hexagonal wurtzite structure. The core-shell nylon 6,6-ZnO nanofiber mats were flexible because of the polymeric core component. Photocatalytic activity of the core-shell nylon 6,6-ZnO nanofiber mats were tested by following the photocatalytic decomposition of rhodamine-B dye. The nylon 6,6-ZnO nanofiber mat, having thinner fiber diameter, has shown better photocatalytic efficiency due to higher surface area of this sample. These nylon 6,6-ZnO nanofiber mats have also shown structural stability and kept their photocatalytic activity for the second cycle test. Our findings suggest that core-shell nylon 6,6-ZnO nanofiber mat can be a very good candidate as a filter material for water purification and organic waste treatment because of their photocatalytic properties along with structural flexibility and stability.

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

    PubMed Central

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

    2016-01-01

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

  17. Performance Assessment of Suture Type, Water Temperature, and Surgeon Skill in Juvenile Chinook Salmon Surgically Implanted with Acoustic Transmitters

    SciTech Connect

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

    2010-05-01

    This study assessed performance of seven suture types in subyearling Chinook salmon Oncorhynchus tshawytscha implanted with acoustic microtransmitters. Nonabsorbable (Ethilon) and absorbable (Monocryl) monofilament and nonabsorbable (Nurolon, silk) and absorbable (Vicryl, Vicryl Plus, Vicryl Rapide) braided sutures were used to close incisions in Chinook salmon. Monocryl exhibited greater suture retention than all other suture types 7 d after surgery. Both monofilament suture types were retained better than all braided suture types at 14 d. Incision openness and tag retention did not differ among suture types. Wound inflammation was similar for Ethilon, Monocryl, and Nurolon at 7 d. Wound ulceration was lower for Ethilon, Monocryl, and Nurolon than for all other suture types at 14 d post-surgery. Fish held in 12°C water had more desirable post-surgery healing characteristics (i.e., higher suture and tag retention and lower incision openness, wound inflammation, and ulceration) at 7 and 14 d after surgery than those held in 17°C water. The effect of surgeon was a significant predictor for all response variables at 7 d. This result emphasizes the importance of including surgeon as a variable in telemetry study analyses when multiple surgeons are used. Monocryl performed better with regard to post-surgery healing characteristics in the study fish. The overall results support the conclusion that Monocryl is the best suture material to close incisions created during surgical implantation of acoustic microtransmitters in subyearling Chinook salmon.

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

    SciTech Connect

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

    2011-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

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

  20. Specialty polymeric membranes. 8: Separation of benzene from benzene/cyclohexane mixtures with nylon 6-graft-poly(butyl methacrylate) membranes

    SciTech Connect

    Yoshikawa, Masakazu; Tsubouchi, Keisuke; Kitao, Toshio

    1999-02-01

    A novel pervaporation membrane was prepared by radical graft polymerization of butyl methacrylate onto nylon 6. The permselectivity toward benzene was increased by the introduction of poly(butyl methacrylate) onto a nylon 6 membrane. From pervaporation and sorption experiments, it was shown that the introduction of poly(butyl methacrylate) onto a nylon 6 membrane leads to the enhancement of permselectivity toward benzene. The solubility data for benzene were described by a combination of simple sorption and specific sorption, while cyclohexane solubility was described by simple sorption.

  1. Deep suture zone in the North Barents Basin

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    Study of sedimentary basin evolution is a part of research for the forecast of oil and gas capacity of the North Barents shelf. Maps of potential fields anomalies are compiled on the basis of the latest geophysical databases, structural maps of the seismic horizons are analyzed, the location of sources of potential fields anomalies are calculated, 3D density and magnetic models of Earth's crust are constructed. Six seismic complexes are allocated in sedimentary cover structure: Devonian - Lower Carboniferous, Upper Carboniferous - Lower Permian, Mid Permian - Lower Triassic, Triassic - Lower Jurassic, Upper Jurassic - Lower Cretaceous, Lower Cretaceous - Quaternary. The research of lateral changes of allocated layers thickness gives an idea of sedimentation in the region on various time intervals. The structural and tectonic scheme of the region is made after analysis of new geologic-geophysical materials. Contact zones of heterogeneous blocks of the crystalline basement are marked, disjunctive dislocations in a sedimentary cover and the upper crust, and also zones of increase of sediments thickness in various seismic complexes are designated. The deep suture zone delimiting Mesozoic and Paleozoic sedimentary basins has the most important geological value among disjunctive zones of the region. This zone stretches along the Admiralty Arch in East part of the North Barents shelf and is marked by negative magnetic anomaly 30-50 km wide. In view of special tectonic value of the suture zone marked by this anomaly we have calculated the 3D magnetic crust model. The sedimentary layers of a model section is based on seismic data. As a result of modeling the studied anomaly of a magnetic field can be approximated by the block of basement rocks of the lowered magnetization (1.2 A/m). The surface of this block is located in a zone of anomaly at a depth of 12-14 km. The asymmetry of anomaly is accounted by an inclination to East of the borders of the block with low

  2. Cyclic fatigue behaviour of fibre reinforced rubber-toughened nylon composite materials

    NASA Astrophysics Data System (ADS)

    Pinot, L.; Gomina, M.; Jernot, J.-P.; Moreau, R.; Nakache, E.

    2005-03-01

    The effects of the amount of rubber, the concentration of fibres and the state of the fibre/matrix interface upon the mechanical behaviour of glass fibre/rubber-toughened nylon ternary blends are checked. First, monotonic tensile tests were carried out on different intermediate materials and then on the ternary blends to derive the stress-strain curves and document the damage mechanisms. Cyclic fatigue tests were implemented on tensile specimens and the results were analysed in terms of the reduction of the Young's modulus, the increase of the hysteresis energy rate in the stress-strain diagram and the temperature rise. These findings were correlated to fractographic observations to assess the role of the different constituents.

  3. Characterization of Nylon 6 Nano Fiber/E-Glass Fiber Reinforced Epoxy Composites

    NASA Astrophysics Data System (ADS)

    Vinod Kumar, T.; Chandrasekaran, M.; Santhanam, V.; Udayakumar, N.

    2017-03-01

    In the paper thermoplastic polymer Nylon-6 is generated in the form of Nanofibers by using an electro spinning method, and concentration of a solution is 4% as a constant then, by varying the process parameters such as flow rate (0.8 ml/hr, 1ml/hr and 1.2 ml/hr) of the solution. The results indicated Nanofibers with 4% concentration and 1 ml/hr produced optimum fibers due to continuous fiber formation. Composites Plates are fabricated by using a Hand lay-up method with different volume fraction (0.5, 1, 2 % v/v) of Nanofibers ratio. Then, the optimum Nanofibers volume ratio (2 % v/v) is reinforced with E-glass fibers and epoxy resin as a matrix. In order to find Nanofibers effect, Mechanical properties like (Tensile, Flexural and Impact) is performed and evaluated.

  4. A method for impregnating nylon transfer membranes with leucocrystal violet for enhancing and lifting bloody impressions.

    PubMed

    Michaud, Amy L; Brun-Conti, Leanora

    2004-05-01

    The objective of this research project was to demonstrate a quick and easy method for impregnating nylon transfer membranes with leucocrystal violet (LCV) for the purpose of lifting and enhancing impressions made in blood. A stamp that would simulate fine detail found in fingerprints or footwear was used to create impressions on a variety of substrates. Four different LCV formulations were tested to determine the effectiveness of the prepared membranes in lifting and enhancing the impressions. Further investigation involved the feasibility of using the LCV membranes in the field by studying the shelf life and storage of the impregnated membranes and the longevity of the lifted impressions. One of the formations studied demonstrated superior lifting and enhancing capabilities, as well as a prolonged shelf life and a resilience of the lifted impressions, thus proving LCV to be an extremely valuable technique.

  5. Analysis of Glass-Filled Nylon in Laser Powder Bed Fusion Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Slotwinski, John; LaBarre, Erin; Forrest, Ryan; Crane, Emily

    2016-03-01

    At the Johns Hopkins University Applied Physics Laboratory (APL), glass bead-filled polyamide (a.k.a. nylon) (GFN) is being used frequently for functional parts and systems, built using a laser-based powder bed fusion (PBF) additive manufacturing (AM) system. Since these parts have performance requirements, it is important to understand the mechanical properties of the additively-made GFN as a function of build orientation and build parameters. In addition, the performance of the AM system used to manufacture these parts must be evaluated in order to understand its capabilities, especially in order to determine the dimensional precision and repeatability of features built with this system. This paper summarizes recent APL efforts to characterize the GFN powder, the mechanical properties of parts made with GFN, and the performance of the laser PBF machine while running GFN using an AM test artifact.

  6. Fiber Reinforcement in Injection Molded Nylon 6/6 Spur Gears

    NASA Astrophysics Data System (ADS)

    Senthilvelan, S.; Gnanamoorthy, R.

    2006-07-01

    Injection molded polymer composite gears are being used in many power and or motion transmission applications. In order to widen the utilization of reinforced polymers for precision motion transmission and noise less applications, the accuracy of molded gears should be increased. Since the injection molded gear accuracy is significantly influenced by the material shrinkage behaviour, there is a need to understand the influence of fiber orientation and gate location on part shrinkage behaviour and hence the gear accuracy. Unreinforced and 20% short glass fiber reinforced Nylon 6/6 spur gears were injection molded in the laboratory and computer aided simulations of gear manufacturing was also carried out. Results of the mold flow simulation of gear manufacturing were correlated with the actual fiber orientation and measured major geometrical parameters of the molded gears. Actual orientation of the fibers near the tooth profile, weld line region and injection points of molded gears were observed using optical microscope and correlated with predicted fiber orientation.

  7. Experimental investigation of the link between static and dynamic wetting by forced wetting of nylon filament.

    PubMed

    Vega, M J; Gouttière, C; Seveno, D; Blake, T D; Voué, M; De Coninck, J; Clarke, A

    2007-10-09

    Forced wetting experiments with various liquids were conducted to study the dynamic wetting properties of nylon filament. The molecular-kinetic theory of wetting (MKT) was used to interpret the dynamic contact angle data and evaluate the contact-line friction zeta0 at the microscopic scale. By taking account of the viscosity of the liquid, zeta0 could be related exponentially to the reversible work of adhesion. This clearly establishes an experimental link between the static and dynamic wetting properties of the material. Moreover, statistical analysis of the equilibrium molecular displacement frequency K0 and the length of the displacements lambda reveals that these two fundamental parameters of the MKT are strongly correlated, not only in the linearized form of the theory (valid close to equilibrium) but also when the nonlinear form of the equations has to be considered at higher wetting speeds.

  8. Mechanical properties of all-suture anchors for rotator cuff repair

    PubMed Central

    Zargar, N.; Smith, R. D. J.; Carr, A. J.

    2017-01-01

    Objectives All-suture anchors are increasingly used in rotator cuff repair procedures. Potential benefits include decreased bone damage. However, there is limited published evidence for the relative strength of fixation for all-suture anchors compared with traditional anchors. Materials and Methods A total of four commercially available all-suture anchors, the ‘Y-Knot’ (ConMed), Q-FIX (Smith & Nephew), ICONIX (Stryker) and JuggerKnot (Zimmer Biomet) and a traditional anchor control TWINFIX Ultra PK Suture Anchor (Smith & Nephew) were tested in cadaveric human humeral head rotator cuff repair models (n = 24). This construct underwent cyclic loading applied by a mechanical testing rig (Zwick/Roell). Ultimate load to failure, gap formation at 50, 100, 150 and 200 cycles, and failure mechanism were recorded. Significance was set at p < 0.05. Results Overall, mean maximum tensile strength values were significantly higher for the traditional anchor (181.0 N, standard error (se) 17.6) compared with the all-suture anchors (mean 133.1 N se 16.7) (p = 0.04). The JuggerKnot anchor had greatest displacement at 50, 100 and 150 cycles, and at failure, reaching statistical significance over the control at 100 and 150 cycles (22.6 mm se 2.5 versus 12.5 mm se 0.3; and 29.6 mm se 4.8 versus 17.0 mm se 0.7). Every all-suture anchor tested showed substantial (> 5 mm) displacement between 50 and 100 cycles (6.2 to 14.3). All-suture anchors predominantly failed due to anchor pull-out (95% versus 25% of traditional anchors), whereas a higher proportion of traditional anchors failed secondary to suture breakage. Conclusion We demonstrate decreased failure load, increased total displacement, and variable failure mechanisms in all-suture anchors, compared with traditional anchors designed for rotator cuff repair. These findings will aid the surgeon’s choice of implant, in the context of the clinical scenario. Cite this article: N. S. Nagra, N. Zargar, R. D. J. Smith, A. J. Carr

  9. Molecular self-assembly of nylon-12 nanorods cylindrically confined to nanoporous alumina

    PubMed Central

    Cao, Yan; Wu, Hui; Higaki, Yuji; Jinnai, Hiroshi; Takahara, Atsushi

    2014-01-01

    Molecular self-assembly of nylon-12 rods in self-organized nanoporous alumina cylinders with two different diameters (65 and 300 nm) is studied with transmission electron microscopy (TEM) and wide-angle X-ray diffraction (WAXD) in symmetrical reflection mode. In a rod with a 300 nm diameter, the tendency of the hydrogen-bonding direction of a γ-form crystal parallel to the long axis of the rod is not clear because of weak two-dimensional confinement. In a rod with a diameter of 65 nm, the tendency of the hydrogen-bonding direction of a γ-form crystal parallel to the long axis of the rod is more distinct because of strong two-dimensional confinement. For the first time, selected-area electron diffraction (SAED) is applied in a transmission electron microscope to a polymer nanorod in order to determine the hydrogen-bond sheet and lamellar orientations. Results of TEM–SAED and WAXD showed that the crystals within the rod possess the γ-form of nylon-12 and that the b axis (stem axis) of the γ-form crystals is perpendicular to the long axis of the rod. These results revealed that only lamellae with 〈h0l〉 directions are able to grow inside the nanopores and the growth of lamellae with 〈hkl〉 (k ≠ 0) directions is stopped owing to impingements against the cylinder walls. The dominant crystal growth direction of the 65 nm rod in stronger two-dimensional confinement is in between the [−201] and [001] directions due to the development of a hydrogen-bonded sheet restricted along the long axis of the rod. PMID:25485124

  10. Laser welding of nylon thin films using a pulsed CO2 waveguide laser

    NASA Astrophysics Data System (ADS)

    Villagomez, R.; Valenzuela, Rogelio; Camacho-Mesa, Roxana B.

    2011-10-01

    In this work, we present an experimental investigation for welding Nylon: Bi-Oriented Polyamide (BOPA) thin films using a CO2 waveguide laser in a pulsed configuration. The material used in this study is Nylon 6, all set in square sheet thin films samples of 100 cm2 with 15 µm thickness. Our optical setup is based on deliver the laser beam all the way through the work piece using X-Y scanning mirrors mounted on galvo-like motors and an f-theta lens with 15 cm focal length and 50 µm focal spot sizes. The fluence (laser energy) is controlled by a pulse signal generator having the possibility to change the pulse repetition rate (PRR) and the pulse width (PW) of the laser beam. Our results show the best weld seam for scanning speeds of 20mm/s and the pulsed laser beam with 2 KHz PRR and 80 µs for the PW time. The scanning speed and trajectory for the welding process are all controlled by a computer in which one can modify the weld parameters. The irradiance at the focal point is set to 1.146 MW/cm2 while the average optical power was set to 22.5W. Our experimental parameters are previously modeled by using COMSOL Multiphysics software were the laser heat source is modeled on the selected material. This model is based on the heat transfer partial differential equation and solved by finite elements procedure. Model results show a perfect agreement with the experiments. Finally, the quality of the welded seam is studied by means of sealed tight and share force critical mechanical test.

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

    NASA Astrophysics Data System (ADS)

    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

  12. Effects of In Utero Thyroxine Exposure on Murine Cranial Suture Growth

    PubMed Central

    Black, Laurel; Bennfors, Grace; Parsons, Trish E.; Elsalanty, Mohammed E.; Yu, Jack C.; Weinberg, Seth M.; Cray, James J.

    2016-01-01

    Large scale surveillance studies, case studies, as well as cohort studies have identified the influence of thyroid hormones on calvarial growth and development. Surveillance data suggests maternal thyroid disorders (hyperthyroidism, hypothyroidism with pharmacological replacement, and Maternal Graves Disease) are linked to as much as a 2.5 fold increased risk for craniosynostosis. Craniosynostosis is the premature fusion of one or more calvarial growth sites (sutures) prior to the completion of brain expansion. Thyroid hormones maintain proper bone mineral densities by interacting with growth hormone and aiding in the regulation of insulin like growth factors (IGFs). Disruption of this hormonal control of bone physiology may lead to altered bone dynamics thereby increasing the risk for craniosynostosis. In order to elucidate the effect of exogenous thyroxine exposure on cranial suture growth and morphology, wild type C57BL6 mouse litters were exposed to thyroxine in utero (control = no treatment; low ~167 ng per day; high ~667 ng per day). Thyroxine exposed mice demonstrated craniofacial dysmorphology (brachycranic). High dose exposed mice showed diminished area of the coronal and widening of the sagittal sutures indicative of premature fusion and compensatory growth. Presence of thyroid receptors was confirmed for the murine cranial suture and markers of proliferation and osteogenesis were increased in sutures from exposed mice. Increased Htra1 and Igf1 gene expression were found in sutures from high dose exposed individuals. Pathways related to the HTRA1/IGF axis, specifically Akt and Wnt, demonstrated evidence of increased activity. Overall our data suggest that maternal exogenous thyroxine exposure can drive calvarial growth alterations and altered suture morphology. PMID:27959899

  13. Acrylic polymer-grafted polypropylene sutures for covalent immobilization or reversible adsorption of vancomycin.

    PubMed

    García-Vargas, M; González-Chomón, C; Magariños, B; Concheiro, A; Alvarez-Lorenzo, C; Bucio, E

    2014-01-30

    Glycidyl methacrylate (GMA) and acrylic acid (AAc) were separately grafted onto polypropylene (PP) monofilament sutures by means of pre-irradiation using a (60)Co γ-source, with the purpose of loading vancomycin via (i) covalent immobilization through the glycidyl groups of GMA and (ii) ionic interaction with AAc moieties. The effect of absorbed radiation dose, monomer concentration, temperature and reaction time on the grafting degree was evaluated in detail. GMA grafting ranged from 25% to 800% while the grafting yield of AAc onto PP could be tuned between 9% and 454%, at doses from 5 to 50 kGy and a dose rate 13.7 kGy/h. Grafting of GMA or AAc decreased the decomposition temperature and made the sutures swellable to a certain extent. GMA grafting led to a continuous, smooth and thick coating, which was suitable for immobilization of up to 1.9 μg vancomycin per gram. The immobilized vancomycin enabled a reduction in the Staphylococcus aureus CFU adhered to the suture surface. On the other hand, dried AAc-functionalized sutures exhibited a rough and cracked surface which was responsible for a minor increase in the coefficient of friction. PP-g-AAc sutures exhibited pH-dependent swelling and remarkably high capability to host vancomycin (up to 109.9 mg/g), particularly those with an intermediate degree of grafting. Some AAc-functionalized sutures were shown able to inhibit bacterial growth after successive challenges with fresh lawns. Therefore, tuning the yield of grafting of GMA or AAc may enable the preparation of drug-suture combination products that retain or release, respectively, antimicrobial agents.

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

    PubMed

    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.

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

    PubMed

    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.

  16. A pilot study evaluating laparoscopic closure of the nephrosplenic space using an endoscopic suturing device in standing horses.

    PubMed

    Bracamonte, José L; Duke-Novakovski, Tanya

    2016-06-01

    This study evaluated the use of an articulating automated suturing device for laparoscopic closure of the nephrosplenic space in standing horses. Closure of the nephrosplenic space was performed in 4 horses using an automated suturing device. Second-look laparoscopy was performed at 5 weeks. A smooth fibrous adhesion formed between the spleen, the perirenal fascia, and the nephrosplenic ligament in 3 of the 4 horses in which the nephrosplenic space was closed using the automated suturing device. In 1 horse, closure of the nephrosplenic space was not possible due to constant breakage of the endoscopic needle. Intra-operative complications encountered with the automated suturing device were tearing of the perirenal fascia, nephrosplenic ligament, and dorsal splenic capsule along with breakage of the needle. The automated suturing device used in this study for laparoscopic closure of the nephrosplenic space resulted in longer surgery times, suffered instrument failures and delivered inadequate suture.

  17. A pilot study evaluating laparoscopic closure of the nephrosplenic space using an endoscopic suturing device in standing horses

    PubMed Central

    Bracamonte, José L.; Duke-Novakovski, Tanya

    2016-01-01

    This study evaluated the use of an articulating automated suturing device for laparoscopic closure of the nephrosplenic space in standing horses. Closure of the nephrosplenic space was performed in 4 horses using an automated suturing device. Second-look laparoscopy was performed at 5 weeks. A smooth fibrous adhesion formed between the spleen, the perirenal fascia, and the nephrosplenic ligament in 3 of the 4 horses in which the nephrosplenic space was closed using the automated suturing device. In 1 horse, closure of the nephrosplenic space was not possible due to constant breakage of the endoscopic needle. Intra-operative complications encountered with the automated suturing device were tearing of the perirenal fascia, nephrosplenic ligament, and dorsal splenic capsule along with breakage of the needle. The automated suturing device used in this study for laparoscopic closure of the nephrosplenic space resulted in longer surgery times, suffered instrument failures and delivered inadequate suture. PMID:27247467

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

    PubMed Central

    Ram, Jagat; Gupta, Nishant; Chaudhary, Manish; Verma, Neelam

    2013-01-01

    Background: A new emerging complication of trans-scleral fixation of posterior chamber (PC) intraocular lens (IOL) with polypropylene suture is high rates of spontaneous dislocation of the IOL due to disintegration or breakage of suture. Materials: We report a new surgical technique of trans-scleral fixation of posterior chamber intraocular lens (SF PCIOL) with steel suture to eliminate the complication of dislocation of IOL fixed with polypropylene suture in one adult and a child. Results: We successfully achieved stable fixation and good centration of IOL after SF PCIOL with steel suture in these patient having inadequate posterior capsular support. Both eyes achieved best corrected visual acuity 20/40 at 18 months follow-up. Conclusions: Steel suture is a viable option for trans-scleral fixation of posterior chamber intraocular lens. PMID:23619504

  19. Internal morphology of the nonsyndromic prematurely fused sagittal suture in the human skull--A preliminary micro-CT study.

    PubMed

    Nowaczewska, W; Ziółkowski, G; Dybała, B

    2015-10-01

    Although nonsyndromic craniosynostosis (NSC) of the sagittal suture is a well-known type of craniosynostosis, little is currently known about the internal morphology of this prematurely fused suture in modern humans. Recently, micro-computed tomography (micro-CT) has been applied as a new tool for the quantitative evaluation of cranial suture morphology. However, so far there are only a small number of reports concerning studies of the internal morphology of prematurely fused sagittal suture in humans using micro-CT. The primary aim of this study was to examine the internal morphology of a completely obliterated sagittal suture in NSC. Two modern human skulls were used in this study: a skull of a child (aged 10 ± 2.5 years) displaying NSC of the sagittal suture and a skull of an adult showing non-prematurely completely obliterated sagittal suture. Quantitative variables of the sagittal sutures were assessed using method proposed by the authors. Porosity, and relative thickness of three bone layers in two examined skulls (inner cortical, diploë and outer cortical) were analysed using micro-CT in three equal sections of the sagittal suture. In the case of the prematurely fused suture, there were statistically significant differences mainly in the mean values of the porosity, thickness and relative thickness of the diploë between the anterior part and the two other parts (central and posterior) of this suture. Significant differences were also observed in some of the analysed variables between the sections of the sagittal suture of the skull with NSC and the normal skull.

  20. Antibacterial suture vs silk for the surgical removal of impacted lower third molars. A randomized clinical study

    PubMed Central

    Sala-Pérez, Sergi; López-Ramírez, Marta; Quinteros-Borgarello, Milva; Valmaseda-Castellón, Eduardo

    2016-01-01

    Background The aim of this study was to evaluate the clinical and microbiological impact of an antibacterial suture (Monocryl® Plus) in the surgical removal of I3M. Material and Methods A “split-mouth”, prospective pilot clinical study was designed involving 20 patients programmed for the surgical removal of I3M. Each side was randomly sutured with Monocryl® Plus or silk suture and removed for microbiological study 72 hours and 7 days after surgery. Presence of SSI, wound bleeding and the degree of discomfort associated with each type of suture material (scored by means of a visual analog scale) were evaluated. The level of contamination of each material was observed under the scanning electron microscope. Results Wound bleeding upon suture removing was slightly greater after 72 hours and 7 days with black silk suture, though the differences were not statistically significant (p=0.752 and p=0.113, respectively). Patient discomfort was very similar with both types of suture material (p=0.861). Only one case of SSI was recorded with black silk suture after 72 hours. Microbiologically, the antibacterial suture showed a lesser presence of microorganisms (p<0.001, at 72h and p=0.033 at 7th day, respectively). The most common bacterial species included grampositive cocci (Streptococcus viridans group, Neisseria spp., Coagulasenegative Staphylococcus and Peptostreptococcus), gramnegative cocci (Veillonella), grampositive Bacilli (Lactobacillus), and gramnegative Bacilli (Prevotella). Conclusions The greatest antibacterial effect of Monocryl Plus suture was observed after 72 hours. According to most authors, there is no doubt that this antibacterial suture can provide little safety in the control of SSI. Key words:Antibacterial suture, monocryl® plus, vicryl® plus, third molar surgery, postoperative infection, surgical site infection (SSI). PMID:26615503

  1. Detection by /sup 125/I-cationized cytochrome c of proteoglycans and glycosaminoglycans immobilized on unmodified and on positively charged nylon 66

    SciTech Connect

    Heimer, R.; Molinaro, L. Jr.; Sampson, P.M.

    1987-09-01

    We have examined the detection by a /sup 125/I-labeled basic protein, cationized cytochrome c, of selected proteoglycans (PGs) and standard preparations of glycosaminoglycans (GAGs) immobilized on Nylon 66 and also on positively charged Nylon 66. Immobilization on Nylon 66 appears to allow a relative freedom of interaction between PGs or GAGs and /sup 125/I-cationized cytochrome c, but a more restricted reaction was observed when PGs and GAGs were immobilized to positively charged Nylon 66. On this support PGs with large numbers of GAG side chains reacted well with /sup 125/I-cationized cytochrome c, but GAGs were minimally reactive. By taking advantage of some of the properties of large-pore agarose-acrylamide gels, rapid partial characterization of some PGs can be accomplished in the 10-ng range, and therefore at a sensitivity equal to PGs with internal biosynthetic labels.

  2. Upper Mantle Structure Around the Trans-European Suture Zone

    NASA Astrophysics Data System (ADS)

    Janutyte, Ilma; Majdanski, Mariusz; Voss, Peter H.; Kozlovskaya, Elena

    2014-05-01

    The Trans-European Suture Zone (TESZ) is the transition between old Proterozoic lithosphere in Northern and Eastern Europe and the younger Phanerozoic lithosphere in Central and Western Europe. The presented study is a part of the PASSEQ 2006-2008 project which is linked to the TOR project realized during 1996-1997. The PASSEQ and the TOR projects aimed to study the lithosphere and asthenosphere structure around the TESZ, but the latter was focused on the northwestern part of the TESZ between Sweden and Denmark - Germany, while the PASSEQ project was focused on the TESZ mainly beneath Poland. During the PASSEQ project 139 short-period and 49 broadband temporary seismic stations were deployed along the transect stretching from Germany throughout Czech Republic and Poland to Lithuania. The array recorded continuous seismic data from May, 2006 to June, 2008. In our study we used data of all available PASSEQ seismic stations and seismic stations of the national seismological networks of the participating countries and compiled a data set of teleseismic P-wave arrivals. The full data set consists of 8308 manually picked arrivals. Due to limited computational power we used the data of the highest quality only, i.e. 6008 picks. The non-linear teleseismic tomography algorithm TELINV was used to obtain the model of P-wave velocity perturbations in the upper mantle around the TESZ. We recovered the upper mantle structure from 70 km down to 350 km in the study area. The results show ±6.5 % P-wave velocity variations compared to the IASP91 velocity model. We found higher velocities beneath the old East European Craton (EEC) east of the TESZ and lower ones beneath the younger Western Europe west of the TESZ. The thickest litosphere was found beneath the EEC (Lithuania) where the higher velocities continue to about 300 km or even more. To the west of the TESZ under the Variscides the average depth of the lithosphere-asthenosphere boundary (LAB) is about 100 km. The TESZ appears

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

    PubMed Central

    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

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

    PubMed Central

    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

  5. A prospective comparison of octyl-2-cyanoacrylate and suture in standardized facial wounds.

    PubMed

    Handschel, J G K; Depprich, R A; Dirksen, D; Runte, C; Zimmermann, A; Kübler, N R

    2006-04-01

    Regarding the cosmetic results of wound closure using tissue adhesives as opposed to sutured wounds, most published studies are performed on children and with non-standardized lacerations, which makes it difficult to transfer the results to facial incisional wounds in adults. There are also conflicting conclusions about the cosmetic results. The purpose of this randomized prospective study was to compare the cosmetic outcomes of wound closure with sutures and octyl-2-cyanoacrylate in standardized facial wounds in adults. To compare very similar facial wounds, the infraorbital cut (lower eyelid incision) was used in 45 patients. The assessment was performed by patients and surgeons blind to the data. Phase-shifting profilometry was used to measure the profile of the scars. No early complications were observed in any group. The wound depth in the tissue adhesive group was significantly greater than in the suture group. There were no differences in the overall cosmetic results among all patients in the two groups. Interestingly, in the younger patients the result of the sutured wounds was superior to that of the adhesive-treated patients. The Dermabond skin adhesive provides a means of closure of facial surgical wounds without early complications, but adjustment of the edges of the wound and the cosmetic result in younger patients are less successful than with thin sutures.

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

    PubMed

    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.

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

    PubMed

    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.

  8. Cellular Midpalatal Suture Changes after Rapid Maxillary Expansion in Growing Subjects: A Case Report

    PubMed Central

    Caprioglio, Alberto; Fastuca, Rosamaria; Zecca, Piero Antonio; Beretta, Matteo; Mangano, Carlo; Piattelli, Adriano; Macchi, Aldo; Iezzi, Giovanna

    2017-01-01

    The present case report aimed to investigate immediate histologic changes in midpalatal suture in humans following rapid maxillary expansion compared to control. Three patients (mean age 8.3 ± 0.9 years) were enrolled in the case report and underwent midpalatal suture biopsy. Two patients underwent treatment before biopsy. The third patient did not show transversal maxillary deficiency and was enrolled as a control. Biopsy samples of midpalatal suture at 7 (subject 1) and 30 days (subject 2) after maxillary expansion as well as of one control (subject 3) were collected and processed for histology. In the control (subject 3) inter-digitations at the palatal suture gap were observed. At 7 days (subject 1) mature bone with small marrow spaces and trabecular bone with the peculiar storiform appearance inside the soft tissue and collagen fibers running parallel only in the central part were present. At 30 days (subject 2), a greater number of newly-formed bone trabeculae with a perpendicular orientation to the long axis of the suture could be seen. At 30 days the fibrous component of bone tissue was less represented compared to the sample at 7 days. Data from the preliminary histological results showed that bone formation was observed in the gap after rapid maxillary expansion, although the healing process was still ongoing. PMID:28287481

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

    SciTech Connect

    Kusy, R.P.; Whitley, J.Q.

    1983-05-01

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

  10. Comparison of fibrin glue and suture in the healing of teat incisions in lactating goats.

    PubMed

    Alan, M; Yener, Z; Tasal, I; Bakir, B

    2008-05-01

    The aims of this study were to investigate whether fibrin glue can be used to close experimentally induced incisions of the teat (mammary papillae) in lactating goats and to compare the healing of the glued with the sutured incisions. Four clinically healthy lactating dairy goats, namely 8 mammary papillae were used. After surgical preparation of the papillae, a 3.5 cm long incision of each papilla was made through skin, muscular layer and mucosa into the papillary sinus. The wounds in the right papillae in all goats were closed with U-shaped uninterrupted 00 chromic catgut sutures. The wounds in the left papillae in all goats were closed, using fibrin glue. One incision was seen to be dehisced and fistulous one day after in fibrin glued teats. The animals were slaughtered 8 days after surgical manipulation. The mammary papillae were removed and examined in the viewpoint on gross and microscopic findings. The healing of wounds was slower and feeble in glued mammary papillary incisions, however faster and stronger in sutured incisions on day 8 after operations. But, available outcomes like less tissue thickness and positive cosmetic results could be obtained byfibrin glue used on mammary papillary incisions, which are very important for teats to be milked by hand and milking machine. Results suggest that it is advisable to use only one or two simple interrupted sutures in teat incisions glued with fibrin to prevent the dehiscence but with a more reliable healing than the sutured incisions.

  11. Retrospective analysis of 697 septoplasty surgery cases: packing versus trans-septal suturing method.

    PubMed

    Cukurova, I; Cetinkaya, E A; Mercan, G C; Demirhan, E; Gumussoy, M

    2012-04-01

    The trans-septal suturing method has been developed in septoplasty as an alternative to packing. This study was carried out to compare the postoperative results of trans-septal suturing with the anterior Merocel packing technique. The study involved 697 patients who underwent septoplasty. Following surgery, patients were randomly divided into two groups, one with trans-septal suturing and the other with Merocel packing. Patients were asked to record pain levels using a visual analogue scale. Postoperative symptoms and complications were compared. A total of 697 nasal operations were evaluated in the postoperative period considering pain, bleeding, haematoma, septal perforation synechiae and septal perforation. The results for haemorrhage, haematoma, synechiae and perforation were not statistically different (p > 0.05) between groups. In contrast, the level of postoperative pain in patients undergoing trans-septal suturing was significantly less than in the group who received Merocel packing (p < 0.05). Patients with Merocel packing had significantly more pain and nasal discomfort when assessed 1 week after intervention. Therefore, the trans-septal suturing technique may be the preferred option to provide higher patient satisfaction.

  12. Electron-Beam Irradiation Effect on Thermal and Mechanical Properties of Nylon-6 Nanocomposite Fibers Infused with Diamond and Diamond Coated Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Imam, Muhammad A.; Jeelani, Shaik; Rangari, Vijaya K.; Gome, Michelle G.; Moura, Esperidiana. A. B.

    2016-02-01

    Nylon-6 is an engineering plastic with excellent properties and processability, which are essential in several industrial applications. The addition of filler such as diamond (DN) and diamond coated carbon nanotubes (CNTs) to form molded composites may increase the range of Nylon-6 applications due to the resulting increase in strength. The effects of electron-beam irradiation on these thermoplastic nanocomposites are either increase in the cross-linking or causes chain scission. In this study, DN-coated CNTs were synthesized using the sonochemical technique in the presence of cationic surfactant cetyltrimethyl ammonium bromide (CTAB). The DN-coated CNTs nanoparticles and diamond nanoparticles were then introduced into Nylon-6 polymer through a melt extrusion process to form nanocomposite fibers. They were further tested for their mechanical (Tensile) and thermal properties (thermogravimetric analysis (TGA), differential scanning calorimetry (DSC)). These composites were further exposed to the electron-beam (160kGy, 132kGy and 99kGy) irradiation using a 1.5MeV electron-beam accelerator, at room temperature, in the presence of air and tested for their thermal and mechanical properties. The best ultimate tensile strength was found to be 690MPa and 864MPa irradiated at 132 for DN/CNTs/Nylon-6 and Diamond/Nylon-6 nanocomposite fiber as compared to 346MPa and 321MPa for DN/CNTs/Nylon-6 and Diamond/Nylon-6 nanocomposite fiber without irradiation. The neat Nylon-6 tensile strength was 240MPa. These results are consistent with the activation energy calculated from TGA graphs. DSC analysis result shows that the slight increase in glass transition temperature (Tg) and decrease in melting temperature (Tm) which was expected from high electron-beam radiation dose.

  13. Near-infrared (NIR) monitoring of Nylon 6 during quenching studied by projection two-dimensional (2D) correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Shinzawa, Hideyuki; Mizukado, Junji

    2016-11-01

    Evolutionary change in supermolecular structure of Nylon 6 during its melt-quenched process was studied by Near-infrared (NIR) spectroscopy. Time-resolved NIR spectra was measured by taking the advantage of high-speed NIR monitoring based on an acousto-optic tunable filter (AOTF). Fine spectral features associated with the variation of crystalline and amorphous structure occurring in relatively short time scale were readily captured. For example, synchronous and asynchronous 2D correlation spectra reveal the initial decrease in the contribution of the NIR band at 1485 nm due to the amorphous structure, predominantly existing in the melt Nylon 6. This is then followed by the emerging contribution of the band intensity at 1535 nm associated with the crystalline structure. Consequently, the results clearly demonstrate a definite advantage of the high-speed NIR monitoring for analyzing fleeting phenomena.

  14. Degradation of Nylon 6,6 Fire-Suppression Casing from Plutonium Glove Boxes Under Alpha and Neutron Irradiation

    DOE PAGES

    Millsap, Donald W.; Cournoyer, Michael E.; Landsberger, Sheldon; ...

    2015-04-23

    Nylon 6,6 tensile specimens, conforming to the casing for self-contained fire extinguisher systems, have been irradiated using both an accelerator He++ ion beam and a 5-Ci PuBe neutron source to model the radiation damage these systems would likely incur over a lifetime of operation within glove boxes. Following irradiation, these samples were mechanically tested using standard practices as described in ASTM D638. The results of the He++ study indicate that the tensile strength of the nylon specimens undergoes some slight (<10%) degradation while other properties of the samples, such as elongation and tangent modulus, appear to fluctuate with increasing dosemore » levels. The He++-irradiated specimens also have a noticeable level of discoloration corresponding to increasing levels of dose. The neutron-irradiated samples show a higher degree of mechanical degradation than the He++-irradiated samples.« less

  15. Degradation of Nylon 6,6 Fire-Suppression Casing from Plutonium Glove Boxes Under Alpha and Neutron Irradiation

    SciTech Connect

    Millsap, Donald W.; Cournoyer, Michael E.; Landsberger, Sheldon; Tesmer, Joseph R.; Wang, Matthew Y.

    2015-04-23

    Nylon 6,6 tensile specimens, conforming to the casing for self-contained fire extinguisher systems, have been irradiated using both an accelerator He++ ion beam and a 5-Ci PuBe neutron source to model the radiation damage these systems would likely incur over a lifetime of operation within glove boxes. Following irradiation, these samples were mechanically tested using standard practices as described in ASTM D638. The results of the He++ study indicate that the tensile strength of the nylon specimens undergoes some slight (<10%) degradation while other properties of the samples, such as elongation and tangent modulus, appear to fluctuate with increasing dose levels. The He++-irradiated specimens also have a noticeable level of discoloration corresponding to increasing levels of dose. The neutron-irradiated samples show a higher degree of mechanical degradation than the He++-irradiated samples.

  16. Osterix/Sp7 limits cranial bone initiation sites and is required for formation of sutures.

    PubMed

    Kague, Erika; Roy, Paula; Asselin, Garrett; Hu, Gui; Simonet, Jacqueline; Stanley, Alexandra; Albertson, Craig; Fisher, Shannon

    2016-05-15

    During growth, individual skull bones overlap at sutures, where osteoblast differentiation and bone deposition occur. Mutations causing skull malformations have revealed some required genes, but many aspects of suture regulation remain poorly understood. We describe a zebrafish mutation in osterix/sp7, which causes a generalized delay in osteoblast maturation. While most of the skeleton is patterned normally, mutants have specific defects in the anterior skull and upper jaw, and the top of the skull comprises a random mosaic of bones derived from individual initiation sites. Osteoblasts at the edges of the bones are highly proliferative and fail to differentiate, consistent with global changes in gene expression. We propose that signals from the bone itself are required for orderly recruitment of precursor cells and growth along the edges. The delay in bone maturation caused by loss of Sp7 leads to unregulated bone formation, revealing a new mechanism for patterning the skull and sutures.

  17. Light-guided localization within tissue using biocompatible surgical suture fiber as an optical waveguide.

    PubMed

    Choi, Woo June; Park, Kwan Seob; Lee, Byeong Ha

    2014-09-01

    In breast-conserving surgery, an optical wire is a useful surgical guiding tool to optically locate small lesions within the breast tissue. However, the use of a long silica glass fiber as the optical wire can be burdensome to patients because of its stiffness and nonbiocompatibility. We investigate the use of a biocompatible fiber for light localization in tissue. A surgical suture with a diameter of 400 μm and a few centimeters long is employed as the biocompatible optical waveguide to transport the visible laser light to the inner tissue site. Optical location is confirmed with glow ball-like red laser illumination at the tip of the suture embedded within a fresh chicken breast tissue. Effective optical power coupling to the suture is made by using a double-cladding fiber coupler. From this preliminary result, we realize practical light localization with biopolymer waveguides.

  18. Suture granuloma mimicking a recurrent sacro-coccygeal pilonidal sinus after Limberg flap.

    PubMed

    Ardelt, Michael; Dittmar, Yves; Schulz, Birte; Rauchfuss, Falk; Scheuerlein, Hubert; Settmacher, Utz

    2014-12-01

    Sacro-coccygeal pilonidal sinus disease is classified as an asymptomatic, acutely abscess-forming or chronic subcutaneous inflammation in the sacro-coccygeal region featuring characteristic pits in the bottom cleft. Due to high rates of recurrence, two flap techniques have been established in the course of the past three decades. One of them is the Karydakis operation, the other option is a rotation flap named Limberg procedure. We report about a case of suture granuloma in the area of a Limberg flap after recurrent pilonidal sinus with extrusion of the suture material, thus mimicking recurrence. In case of recurrent pilonidal sinus following plastic coverage or primary closure, respectively, the differential diagnosis of suture granuloma should be considered.

  19. Prevalence of biofilms on surgical suture segments in wounds of dogs, cats, and horses.

    PubMed

    König, L; Klopfleisch, R; Kershaw, O; Gruber, A D

    2015-03-01

    The formation of biofilms on surgical implants is thought to play a major role in chronic infection and wound-healing disorders and has been rarely described in veterinary medicine. Due to poor and unreliable results from bacterial culturing, histology may be an economic tool for the detection of biofilms. In this study, the prevalence of biofilms on surgical suture materials and swabs with chronic wound-healing complications in dogs, cats, and horses was assessed by histologic examination using hematoxylin and eosin, Gram, and Giemsa stains, as well as periodic acid-Schiff reaction. Of the 91 tissue samples with intralesional suture material or swab residues associated with inflammation, only 2 contained bacterial colonies arranged in an extracellular polymeric matrix consistent with a biofilm. The results of this study suggest that biofilms on suture material may occur in veterinary medicine.

  20. Performance Assessment of Suture Type in Juvenile Chinook Salmon Surgically Implanted with Acoustic Transmitters

    SciTech Connect

    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.

  1. Limited open repair of ruptured Achilles tendons with Bunnel-type sutures.

    PubMed

    Park, H G; Moon, D H; Yoon, J M

    2001-12-01

    A new method of repairing Achilles tendons, which uses a small medial skin incision with a Bunnel-type suture, was performed on 14 patients, and the clinical results were found satisfying. In order to restore the Achilles tendon to its original length, restore tensile strength in the suture site, and minimize injury to the sural nerve, an operative procedure has been devised which uses a limited open repair with a Bunnel-type suture. We followed 14 patients who had undergone the new procedure for a mean interval of 26 months after the injury. They returned to work in six weeks and to playing sports in 25 weeks. There were no cases of late rerupture nor injuries to the sural nerve. This technique approximated the preinjury length and resting tension of the musculo-tendinous apparatus and minimized sural nerve injury.

  2. The Derivatization of Polystyrene and Nylon Beads. A Controlled Introduction of Functional Groups for Immobilization of Antibody Protein.

    DTIC Science & Technology

    1983-05-01

    methanesulfonic acid . After overnight incubation at room tem- perature, the plates (balls) were extensively washed with distilled water and dried. The...plates (balls) were then filled (covered) with a mixture of glacial acetic acid /fuming nitric acid (1:1) and placed in a 400C incubator. After 4 hrs, the...prepared by hydrolyzing with 3N HCl as previously de- scribed’ or with succinic anhydride Coupling of Goat anti-rabbit ISG to Nylon balls: Goat anti-rabbit

  3. Flow injection analysis with on-line nylon powder extraction for room-temperature phosphorescence determination of thiabendazole.

    PubMed

    Piccirilli, G N; Escandar, G M

    2009-07-30

    A fast and very selective flow-through phosphorescence optosensor was designed and characterized for the determination of the fungicide thiabendazole in water samples. For the first time, thiabendazole was determined using a flow-through optosensor based on the phosphorescence signals obtained when it is retained in a solid support. While thiabendazole does not phosphoresce in packing materials commonly used to fill the flow-cell, significant emission signals are observed when it is retained on nylon powder in the presence of iodide and sulfite. The experimental set-up was based on a flow-injection manifold coupled to an on-line phosphorescence detector containing nylon powder packed in a conventional flow-cell. Potassium iodide and sodium sulfite were added to sample aliquots to improve the thiabendazole phosphorescence and injected in the flow manifold using water as carrier. After the phosphorescence emission was registered, the analyte was eluted from the packed nylon with a 65% (v/v) methanol-water mixture. Optimal instrumentation, experimental and flow conditions were evaluated. Using a sample volume of 2000 microL, the analytical signal showed a very good linearity in the range 12.9-110 ng mL(-1), with a detection limit of 4.5 ng mL(-1), and a sample throughput of about 14 samples per hour. The effects of the presence of concomitant species in the thiabendazole phosphorescence signal were studied, and a comparison with the fluorescence nylon-powder optosensor was carried out and discussed. Finally, the applicability of the proposed optosensor was tested in water samples, and satisfactory recoveries ranging between 97% and 105% were obtained.

  4. Comparison of Reactive Mercury Concentrations Measured Simultaneously Using KCl-coated Denuders, Nylon Membranes, and Cation Exchange Membranes

    NASA Astrophysics Data System (ADS)

    Gustin, M. S.; Huang, J.; Miller, M. B.; Weiss-Penzias, P. S.

    2012-12-01

    There is much debate about the chemistry of reactive gaseous and particle bound mercury (Hg) in the atmosphere, and the processes associated with formation. In addition, there are concerns regarding the interferences and calibration of the widely used Tekran® 2537/1130/1135 Hg measurement system. To investigate these we developed simple laboratory and field sampling systems designed to collect and analyze reactive Hg (Hg (II), Hg (I) and/or particle bound). A manifold system was applied in the laboratory, and in the field, in-series and -parallel membranes, flow controllers and pumps were utilized. Both systems actively collected reactive Hg using nylon membranes and cation exchange membranes alongside measurements made using the Tekran® system. The analytical system consisted of step wise 2.5 minute thermo-desorption and Hg quantification by cold vapor atomic fluorescence. In the laboratory, we compared the efficiency of these surfaces for collection of HgO, HgCl2, and HgBr2 when permeated into Hg and oxidant free air, and ambient filtered air. Other tests are ongoing. Thus far, results show concentrations measured by the cation exchange membrane were two-to-three fold greater than that measured by the nylon membranes, and three-to -four fold greater than that measured by the KCl-coated annual denuder. Thermo-desorption profiles obtained using nylon membranes show slightly different patterns associated with the reactive Hg compounds as permeated and tested. Field measurements were made at two locations in Reno, Nevada (a high traffic site and an agricultural area) and at Elkhorn Slough, California (marine site). Desorption profiles from nylon membrane differed by site and by time of year. Although the influence of aerosol on this measurement has not been explored, field results suggest different forms of reactive Hg were present in the atmosphere as a function of season and location.

  5. Detection of gamma-ray emission in the region of the supernova remnants G296.5+10.0 and G166.0+4.3

    NASA Astrophysics Data System (ADS)

    Araya, Miguel

    2013-09-01

    52 months of accumulated observations by the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope in the region of the supernova remnants G296.5+10.0 (PKS 1209-51/52) and G166.0+4.3 (VRO 42.05.01) are analysed. GeV emission is detected coincident with the position of the sources at the ≃5σ and 11σ levels above the background, respectively, for the best-fitting spectral and spatial scenarios. The gamma-ray spectrum of the sources can be described with a power law in energy. G166.0+4.3 shows a soft GeV spectrum while that of G296.5+10.0 is flat (in the νFν representation). The origin of the gamma-ray emission from the sources is explored. Both leptonic and hadronic mechanisms can account for the high-energy emission from G296.5+10.0, while a leptonic scenario is preferred for G166.0+4.3.

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

    PubMed Central

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

    2014-01-01

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

  7. Transseptal suturing technique in septoplasty: impact on bacteremia and nosocomial colonization.

    PubMed

    Ismi, Onur; Ozcan, Cengiz; Vayısoğlu, Yusuf; Öztürk, Candan; Tek, Sebahat Aslan; Görür, Kemal

    2017-02-20

    Although effects of Merocel(®) nasal packs and silicone splints on nasal flora alterations and bacteremia formation after septoplasty were assessed before, the effect of transseptal suturing technique has not been studied yet. The objective of this study is to compare nasal flora alterations and bacteremia occurrence rates between Merocel packs, silicone splints, and transseptal suturing technique in septoplasty. Ninety patients were divided into three groups randomly: Merocel packing (Group M), silicone splint (Group S), and transseptal suturing without packing (Group T). Group M and S received prophylactic antibiotics and antibiotic pomade application to packs, whereas neither antibiotic prophylaxis nor topical pomade was applied to Group T. Preoperative, after pack removal and 1 month after pack removal nasal swab cultures and preoperative, immediately after surgery and 24 h after surgery blood cultures were taken from all patients. Group M increased Methicillin-sensitive Staphylococcus aureus (MSSA) colonization (p = 0.003) and decreased normal flora colonization (p = 0.038), whereas Group S and T did not affect MSSA or normal flora colonization (p > 0.05). Antibiotic prophylaxis did not affect MSSA colonization (p = 0.14), whereas decreased normal flora colonization (p = 0.029). Transseptal suturing did not prevent bacteremia formation. Postoperative increasing of MSSA colonization in nasal cavity for septoplasty patients can be prevented by using transseptal suturing technique or silicone splints instead of Merocel packing, rather than applying prophylactic antibiotic treatment. Using transseptal suturing does not prevent bacteremia formation during septal surgery. These findings should be kept in mind to prevent postoperative life-threatening infective complications of septoplasty especially in immunosuppressive patients and patients with cardiovascular diseases.

  8. Absorbable or nonabsorbable suture materials for closure of the dura mater?

    PubMed

    Vällfors, B; Hansson, H A; Svensson, J

    1981-10-01

    This study was undertaken to determine which suture material would give the best results for closure of the dura mater. Because there is no need for the suture to remain longer than until healing has occurred and as remaining foreign material will predispose to foreign body reactions and infection, it was considered important to test new absorbable materials like polyglactin 910 (Vicryl) and polyglycolic acid (Dexon) for closure of the dura mater. The reactions from these materials were compared to those of silk and polyester (Ethibond) in dogs 60 days after the suture of dural incisions. The quality of healing with respect to the smoothness of the subdural surface, the presence of adhesions between sutures and the brain surface, the degree of absorption of the material, and reactions around the sutures were evaluated. Vicryl gave the best results, providing a smooth subdural surface without adhesions. It was almost totally absorbed when healing was completed, in contrast to Dexon and the other materials. The cellular reaction around Vicryl was slight. Silk, Ethibond, and Dexon protruded from the subdural surface and adhesions to the arachnoid were common. When the dura mater was removed, these adhesions tore off the leptomeninges with their vascular supply to the cortex. The results of these experiments seem to justify the recommendation of Vicryl for suturing of the dura mater. Such an absorbable material decreases the risk of foreign body reactions, and infections will be more easily combated because of the absence of foreign material. The lack of subdural adhesions is an advantage if reoperation is necessary.

  9. Self-tapping ability of carbon fibre reinforced polyetheretherketone suture anchors.

    PubMed

    Feerick, Emer M; Wilson, Joanne; Jarman-Smith, Marcus; Ó'Brádaigh, Conchur M; McGarry, J Patrick

    2014-10-01

    An experimental and computational investigation of the self-tapping ability of carbon fibre reinforced polyetheretherketone (CFR-PEEK) has been conducted. Six CFR-PEEK suture anchor designs were investigated using PEEK-OPTIMA® Reinforced, a medical grade of CFR-PEEK. Experimental tests were conducted to investigate the maximum axial force and torque required for self-taping insertion of each anchor design. Additional experimental tests were conducted for some anchor designs using pilot holes. Computational simulations were conducted to determine the maximum stress in each anchor design at various stages of insertion. Simulations also were performed to investigate the effect of wall thickness in the anchor head. The maximum axial force required to insert a self-tapping CFR-PEEK suture anchor did not exceed 150 N for any anchor design. The maximum torque required to insert a self-tapping CFR-PEEK suture anchor did not exceed 0.8 Nm. Computational simulations reveal significant stress concentrations in the region of the anchor tip, demonstrating that a re-design of the tip geometry should be performed to avoid fracture during self-tapping, as observed in the experimental component of this study. This study demonstrates the ability of PEEK-OPTIMA Reinforced suture anchors to self-tap polyurethane foam bone analogue. This provides motivation to further investigate the self-tapping ability of CFR-PEEK suture anchors in animal/cadaveric bone. An optimised design for CFR-PEEK suture anchors offers the advantages of radiolucency, and mechanical properties similar to bone with the ability to self-tap. This may have positive implications for reducing surgery times and the associated costs with the procedure.

  10. Suture zones of the Urals as integral prospective ore-bearing tectonic structures

    NASA Astrophysics Data System (ADS)

    Koroteev, V. A.; Sazonov, V. N.; Ogorodnikov, V. N.; Polenov, Yu. A.

    2009-04-01

    Rift-related (1.2 Ga) and collision (380-240 Ma) suture zones of the Urals are described. The riftrelated suture zones comprise an ultramafic-gabbro complex with titanomagnetite mineralization, an ultramafic complex with chromite mineralization, and a complex of alkali granitoids with rare-metal (including REE) mineralization accompanied by K-feldspathites, albitites, and calcite metasomatic rocks. The collision suture zones are distinguished by early collision granitoids specialized for tungsten (scheelite) and gold, as well as by raremetal granites and such derivatives of them as pegmatite and greisen with rare-metal and colored-stone mineralization. The suture zones are characterized by long-term (up to 80 Ma or more) continuous-discontinuous periods of ore deposition; heterogeneous sources of ore matter and ore-bearing fluids; a polyelemental composition of lithogeochemical halos and an integral mineral composition of altered wall rocks; and the occurrence of mafic, intermediate, and felsic dikes at large gold deposits, as well as wide variations in PT parameters of the ore-forming process: T = 620-150°C and P = 3.2-0.6 kbar. Collision played a dual role in ore formation. On the one hand, collision led to deformation and metamorphism of precollision massive sulfide deposits and, to a lesser degree, Au-bearing Fe and Cu skarn and porphyry copper deposits, and, on the other hand, to the formation of new gold, rare-metal, quartz, colored-stone, talc, muscovite, and noble serpentine deposits. As a rule, this polygenetic mineralization differs in age and is related to collision volcanic and plutonic complexes. This diversity can be a good basis for metallogenic analysis, forecasting, and prospecting of various metallic deposits and industrial minerals. Polygenetic mineralization of various age known in suture zones is accompanied by integral lithogeochemical and metasomatic halos characterized by a continuous-discontinuous history. The complexity of ore

  11. Electrospun nylon-6 spider-net like nanofiber mat containing TiO(2) nanoparticles: a multifunctional nanocomposite textile material.

    PubMed

    Pant, Hem Raj; Bajgai, Madhab Prasad; Nam, Ki Taek; Seo, Yun A; Pandeya, Dipendra Raj; Hong, Seong Tshool; Kim, Hak Yong

    2011-01-15

    In this study, electrospun nylon-6 spider-net like nanofiber mats containing TiO(2) nanoparticles (TiO(2) NPs) were successfully prepared. The nanofiber mats containing TiO(2) NPs were characterized by SEM, FE-SEM, TEM, XRD, TGA and EDX analyses. The results revealed that fibers in two distinct sizes (nano and subnano scale) were obtained with the addition of a small amount of TiO(2) NPs. In low TiO(2) content nanocomposite mats, these nanofiber weaves were found uniformly loaded with TiO(2) NPs on their wall. The presence of a small amount of TiO(2) NPs in nylon-6 solution was found to improve the hydrophilicity (antifouling effect), mechanical strength, antimicrobial and UV protecting ability of electrospun mats. The resultant nylon-6/TiO(2) antimicrobial spider-net like composite mat with antifouling effect may be a potential candidate for future water filter applications, and its improved mechanical strength and UV blocking ability will also make it a potential candidate for protective clothing.

  12. A literature review of the military uses of silver-nylon dressings with emphasis on wartime operations.

    PubMed

    Barillo, David J; Pozza, Morano; Margaret-Brandt, Mary

    2014-12-01

    Medical support of military operations involves treatment of massive soft tissue wounds, thermal burns, open fractures, blast injuries and traumatic amputations under conditions that are often austere and far from supply lines. Military hospitals, as recently deployed in Iraq and Afghanistan, are designed and equipped for stabilization and rapid transfer of injured patients back to their home nation. These austere facilities are often tasked with the emergency or long-term treatment of local populations when injured or burned, further stressing the medical resupply system. Pathogens encountered in contemporary wartime practice are increasingly resistant to antibiotics. Ionic silver is bactericidal against a broad spectrum of bacteria, yeasts and fungi, has been utilized as a topical antiseptic for over 100 years, and has no known clinically-relevant resistance. Silver-nylon dressings, initially stocked in US military hospitals as a burn dressing, are now finding utility as a universal dressing for all types of combat wounds. Compared to conventional burn dressings, they are easier to transport and store, easier to use, and do not need to be changed as frequently, allowing for conservation of nursing resources. In this literature review, the recent military uses of silver-nylon dressings are examined. The stockpiling and use of silver-nylon as a universal military burn and wound dressing is advocated.

  13. Uncertainties of Gaseous Oxidized Mercury Measurements Using KCl-Coated Denuders, Cation-Exchange Membranes, and Nylon Membranes: Humidity Influences.

    PubMed

    Huang, Jiaoyan; Gustin, Mae Sexauer

    2015-05-19

    Quantifying the concentration of gaseous oxidized mercury (GOM) and identifying the chemical compounds in the atmosphere are important for developing accurate local, regional, and global biogeochemical cycles. The major hypothesis driving this work was that relative humidity affects collection of GOM on KCl-coated denuders and nylon membranes, both currently being applied to measure GOM. Using a laboratory manifold system and ambient air, GOM capture efficiency on 3 different collection surfaces, including KCl-coated denuders, nylon membranes, and cation-exchange membranes, was investigated at relative humidity ranging from 25 to 75%. Recovery of permeated HgBr2 on KCl-coated denuders declined by 4-60% during spikes of relative humidity (25 to 75%). When spikes were turned off GOM recoveries returned to 60 ± 19% of permeated levels. In some cases, KCl-coated denuders were gradually passivated over time after additional humidity was applied. In this study, GOM recovery on nylon membranes decreased with high humidity and ozone concentrations. However, additional humidity enhanced GOM recovery on cation-exchange membranes. In addition, reduction and oxidation of elemental mercury during experiments was observed. The findings in this study can help to explain field observations in previous studies.

  14. Correlating antimicrobial activity and model membrane leakage induced by nylon-3 polymers and detergents.

    PubMed

    Hovakeemian, Sara G; Liu, Runhui; Gellman, Samuel H; Heerklotz, Heiko

    2015-09-14

    Most antimicrobial peptides act upon target microorganisms by permeabilizing their membranes. The mode of action is often assessed by vesicle leakage experiments that use model membranes, with the assumption that biological activity correlates with the permeabilization of the lipid bilayer. The current work aims to extend the interpretation of vesicle leakage results and examine the correlation between vesicle leakage and antimicrobial activity. To this end, we used a lifetime-based leakage assay with calcein-loaded vesicles to study the membrane permeabilizing properties of a novel antifungal polymer poly-NM, two of its analogs, and a series of detergents. In conjunction, the biological activities of these compounds against Candida albicans were assessed and correlated with data from vesicle leakage. Poly-NM induces all-or-none leakage in polar yeast lipid vesicles at the polymer's MIC, 3 μg mL(-1). At this and higher concentrations, complete leakage after an initial lag time was observed. Concerted activity tests imply that this polymer acts independently of the detergent octyl glucoside (OG) for both vesicle leakage and activity against C. albicans spheroplasts. In addition, poly-NM was found to have negligible activity against zwitterionic vesicles and red blood cells. Our results provide a consistent, detailed picture of the mode of action of poly-NM: this polymer induces membrane leakage by electrostatic lipid clustering. In contrast, poly-MM:CO, a nylon-3 polymer comprised of both cationic and hydrophobic segments, seems to act by a different mechanism that involves membrane asymmetry stress. Vesicle leakage for this polymer is transient (limited to <100%) and graded, non-specific among zwitterionic and polar yeast lipid vesicles, additive with detergent action, and correlates poorly with biological activity. Based on these results, we conclude that comprehensive leakage experiments can provide a detailed description of the mode of action of membrane

  15. Correlating antimicrobial activity and model membrane leakage induced by nylon-3 polymers and detergents

    PubMed Central

    Hovakeemian, Sara G.; Liu, Runhui; Gellman, Samuel H.; Heerklotz, Heiko

    2015-01-01

    Most antimicrobial peptides act upon target microorganisms by permeabilizing their membranes. The mode of action is often assessed by vesicle leakage experiments that use model membranes, with the assumption that biological activity arises from permeabilization of the lipid bilayer. The current work aims to extend the interpretation of vesicle leakage results and examine the correlation between vesicle leakage and antimicrobial activity. To this end, we used a lifetime-based leakage assay with calcein-loaded vesicles to study the membrane permeabilizing properties of a novel antifungal polymer poly-NM, two of its analogs, and a series of detergents. In conjunction, the biological activities of these compounds against Candida albicans were assessed and correlated with data from vesicle leakage. Poly-NM induces all-or-none leakage in polar yeast lipid vesicles at the polymer’s MIC, 3 μg/mL. At this and higher concentrations, complete leakage after an initial lag time was observed. Concerted activity tests imply that this polymer acts independently of the detergent octyl glucoside (OG) for both vesicle leakage and activity against C. albicans spheroplasts. In addition, Poly-NM was found to have negligible activity against zwitterionic vesicles and red blood cells. Our results provide a consistent, detailed picture of the mode of action of Poly-NM: this polymer induces membrane leakage by electrostatic lipid clustering. In contrast, Poly-MM:CO, a nylon-3 polymer comprised of both cationic and hydrophobic segments, seems to act by a different mechanism that involves membrane asymmetry stress. Vesicle leakage for this polymer is transient (limited to <100%) and graded, non-specific among zwitterionic and polar yeast lipid vesicles, additive with detergent action, and correlates poorly with biological activity. Based on these results, we conclude that comprehensive leakage experiments can provide a detailed description of the mode of action of membrane permeabilizing

  16. Functional Effects of Delivering Human Mesenchymal Stem Cell-Seeded Biological Sutures to an Infarcted Heart

    PubMed Central

    Hansen, Katrina J.; Favreau, John T.; Guyette, Jacques P.; Tao, Ze-Wei; Coffin, Spencer T.; Cunha-Gavidia, Anny; D'Amore, Brian; Perreault, Luke R.; Fitzpatrick, John P.; DeMartino, Angelica; Gaudette, Glenn R.

    2016-01-01

    Abstract Stem cell therapy has the potential to improve cardiac function after myocardial infarction (MI); however, existing methods to deliver cells to the myocardium, including intramyocardial injection, suffer from low engraftment rates. In this study, we used a rat model of acute MI to assess the effects of human mesenchymal stem cell (hMSC)-seeded fibrin biological sutures on cardiac function at 1 week after implant. Biological sutures were seeded with quantum dot (Qdot)-loaded hMSCs for 24 h before implantation. At 1 week postinfarct, the heart was imaged to assess mechanical function in the infarct region. Regional parameters assessed were regional stroke work (RSW) and systolic area of contraction (SAC) and global parameters derived from the pressure waveform. MI (n = 6) significantly decreased RSW (0.026 ± 0.011) and SAC (0.022 ± 0.015) when compared with sham operation (RSW: 0.141 ± 0.009; SAC: 0.166 ± 0.005, n = 6) (p < 0.05). The delivery of unseeded biological sutures to the infarcted hearts did not change regional mechanical function compared with the infarcted hearts (RSW: 0.032 ± 0.004, SAC: 0.037 ± 0.008, n = 6). The delivery of hMSC-seeded sutures exerted a trend toward increase of regional mechanical function compared with the infarcted heart (RSW: 0.057 ± 0.011; SAC: 0.051 ± 0.014, n = 6). Global function showed no significant differences between any group (p > 0.05); however, there was a trend toward improved function with the addition of either unseeded or seeded biological suture. Histology demonstrated that Qdot-loaded hMSCs remained present in the infarcted myocardium after 1 week. Analysis of serial sections of Masson's trichrome staining revealed that the greatest infarct size was in the infarct group (7.0% ± 2.2%), where unseeded (3.8% ± 0.6%) and hMSC-seeded (3.7% ± 0.8%) suture groups maintained similar infarct sizes. Furthermore, the remaining suture area

  17. ASSESSMENT OF MECHANICAL AND MANUAL SUTURE IN THE SURGICAL TREATMENT OF THE PHARYNGOESOPHAGEAL DIVERTICULUM

    PubMed Central

    de AQUINO, José Luis Braga; CHAGAS, José Francisco Salles; SAID, Marcelo Manzano; PASCOAL, Maria Beatriz Nogueira; BRANDI-FILHO, Luis Antonio; PEREIRA, Douglas Alexandre Rizzanti; FRUET, Fernanda

    2015-01-01

    Background: The occurrence of the pharyngoesophageal, or Zenker diverticulum is not frequent in the national scenario, and the technique of the diverticulectomy with cricomyotomy in medium and great dimension diverticula is still the most indicated. Because the resection of the diverticulum requires the suture of the pharynx, dehiscence can occur, thereafter delaying swallowing. Hence, the idea is to accomplish this surgical procedure, comparing the manual and mechanical suture, in order to evaluate the real benefit of the mechanical technique. Aim: To evaluate the results of the pharyngoesophageal diverticulectomy with cricomyotomy using manual and mechanical suture with regard to local and systemic complications. Method: Fifty-seven patients with pharyngoesophageal diverticula diagnosed through high digestive endoscopy and pharyngeal esophagogram were studied. The applied surgical technique was diverticulectomy with myotomy of the cricopharyngeal muscle, done in 24 patients (42.2%) the mechanical suture (group A) with the mechanical linear suture device and in 33 (57.8%) a manual closure of the pharynx (group B). Results: In the postoperative period, one patient of group A (4.1%) presented fistula caused by dehiscence of the pharyngeal suture, and three of group B (15.1%) presented the same complication, with a good outcome using a conservative treatment. In the same group, three patients (9.0%) presented stenosis of the suture of the pharynx, with good outcome and with endoscopic dilatations, and no patient from group A presented such complication. Lung infection was present in five patients, being two (8.3%) of group A and three (9.0%) on B, having good outcomes after specific treatment. In the late review, done with 43 patients (94.4%) of group A and 22 (88.0%) on B, the patients declared to be pleased with the surgical procedure, because they were able to regain normal swallowing. Conclusion: The diverticulectomy with myotomy and pharyngeal closure using

  18. A sensitivity analysis to the role of the fronto-parietal suture in Lacerta bilineata: a preliminary finite element study.

    PubMed

    Moazen, Mehran; Costantini, David; Bruner, Emiliano

    2013-02-01

    Cranial sutures are sites of bone growth and development but micromovements at these sites may distribute the load across the skull more evenly. Computational studies have incorporated sutures into finite element (FE) models to assess various hypotheses related to their function. However, less attention has been paid to the sensitivity of the FE results to the shape, size, and stiffness of the modeled sutures. Here, we assessed the sensitivity of the strain predictions to the aforementioned parameters in several models of fronto-parietal (FP) suture in Lacerta bilineata. For the purpose of this study, simplifications were made in relation to modeling the bone properties and the skull loading. Results highlighted that modeling the FP as either an interdigitated suture or a simplified butt suture, did not reduce the strain distribution in the FP region. Sensitivity tests showed that similar patterns of strain distribution can be obtained regardless of the size of the suture, or assigned stiffness, yet the exact magnitudes of strains are highly sensitive to these parameters. This study raises the question whether the morphogenesis of epidermic scales in the FP region in the Lacertidae is related to high strain fields in this region, because of micromovement in the FP suture.

  19. Effect of different percent loadings of nanoparticles and food processing conditions on the properties of nylon 6 films

    NASA Astrophysics Data System (ADS)

    Allafi, Ahmad R.

    Nylon 6 organoclay nanocomposites were prepared by melt processing using a twin screw extruder. Five different films were produced with five different % loadings (0, 2, 4, 6, and 8%). This study had three main objectives. The first was to investigate the effects of loading percentages on the barrier, thermal and mechanical properties of nylon 6 nanocomposite materials. The second was to study the effects of 0, 50 and 80% RH on the oxygen permeation of the nylon 6/nanocomposite films. The third was to investigate the properties of nylon 6 nanocomposite materials exposed to typical food processing conditions. These films were tested for their permeabilities to oxygen (OTR), carbon dioxide (CO2TR), and water vapor (WVTR). Thermal properties testing on the samples included differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Tensile strength at break, tensile modulus at break, and the percent elongation for the five films were examined using an INSTRON tester. Transmission electron microscopy (TEM) was used to investigate the morphology of the five films. Results showed that all gas barriers significantly increased with percent loading but there were no significant differences (P>0.05) between the 6 and 8% for the CO2TR. For the DMA, the storage modulus also significantly increased (P<0.05) with increasing loading except between the 2 and 4% concentrations. For the DSC analyses, enthalpy of fusion decreased slightly from an average of 39 J/g (control) to 32J/g (8% loading). The melt temperature also decreased from 227 to 222°C between those loadings. High pressure processed samples had the highest barrier against oxygen permeation when compared with the retorted and controls. Retorting seemed to reduce the tensile strength slightly; however, no significant changes in modulus and elongation occurred after retorting and HPP. These results showed that increasing percent loadings increased the stiffness of the material at the expense of its

  20. [Vehicle-assisted suicide with a nylon rope causing complete decapitation].

    PubMed

    Blässer, Katharina; Tatschner, Thomas; Bohnert, Michael

    2013-01-01

    The present case deals with the unusual suicide method of a 36-year-old man who fastened one end of a nylon rope to a tree, guided the other end into a van through the open tailgate and placed the loop round his neck. Then he stepped on the accelerator. Before, he had marked the point on the ground where the rope would tighten. As the rope tightened complete decapitation occurred at a speed of about 35 km/h. Autopsy showed a nearly circular abrasion zone around the site of transection slightly ascending towards the nape, a fracture of the cervical spine between the 3rd and 4th vertebra and a fracture of the thoracic spine between the 7th and 8th vertebra. The test for air embolism of the heart was positive. Macroscopically, no evidence of blood aspiration was found. Histological investigation showed general anaemia and minor blood aspiration in the lungs. Wound morphology was largely in line with the injury patterns described after decapitation in the literature. However, our results differed in that blood aspiration was discernible only under the microscope and there was a second fracture of the spine. Decapitation as a suicide method is an expression of enormous autoaggression and is categorized as a "hard" suicide method. It is used predominantly by men and its occurrence in the spectrum of suicidal actions is rare. Police investigations revealed that the man had led a sort of double life with a sexually motivated background and had suffered from depressive episodes.