Sample records for single-layer continuous suture

  1. Single-layer versus double-layer laparoscopic intracorporeally sutured gastrointestinal anastomoses in the canine model. (United States)

    Tavakoli, Azine; Bakhtiari, Jalal; Khalaj, Ali Reza; Gharagozlou, Mohammad Javad; Veshkini, Abbas


    The objective of this study was to compare the gross and histopathologic changes following 1- versus 2-layer hand-sewn suture techniques in laparoscopic gastrointestinal anastomosis in dogs. This was an experimental prospective study of 16 healthy mixed breed male and female dogs. Animals were randomly divided into 2 groups. Two-layer side-to-side hand-sewn laparoscopic gastrojejunostomies were performed in group A, so that simple interrupted sutures were placed in the outer layer and simple continuous suture was used in the inner layer. The 1-layer simple continuous anastomosis between the stomach and jejunum was done in group B precisely. Specimen were collected from the sites of anastomosis, and H&E statining was performed for light microscopic studies. All animals survived the surgery. There was no gross inflammation, ischemia, apparent granulation tissue, abscess or fistula formation, leakage or stricture formation, and all sites of anastomosis were patent. Several adhesion formations were found in the abdomen with the higher incidence in the control group. Mean scores of leukocyte infiltration and granulation tissue formation at the sites of anastomosis were statistically insignificant between groups (P>0.05). Gross and histopathologic findings revealed that hand-sewn laparoscopic gastrointestinal anastomosis with the 1-layer suture technique is comparable to the 2-layer suture technique.

  2. Design of a Single-Layer Microchannel for Continuous Sheathless Single-Stream Particle Inertial Focusing. (United States)

    Zhang, Yan; Zhang, Jun; Tang, Fei; Li, Weihua; Wang, Xiaohao


    High-throughput, high-precision single-stream focusing of microparticles has a potentially wide range of applications in biochemical analysis and clinical diagnosis. In this work, we develop a sheathless three-dimensional (3D) particle-focusing method in a single-layer microchannel. This novel microchannel consists of periodic high-aspect-ratio curved channels and straight channels. The proposed method takes advantage of both the curved channels, which induce Dean flow to promote particle migration, and straight channels, which suppress the remaining stirring effects of Dean flow to stabilize the achieved particle focusing. The 3D particle focusing is demonstrated experimentally, and the mechanism is analyzed theoretically. The effects of flow rate, particle size, and cycle number on the focusing performance were also investigated. The experimental results demonstrate that polystyrene particles with diameters of 5-20 μm can be focused into a 3D single file within seven channel cycles, with the focusing accuracy up to 98.5% and focusing rate up to 98.97%. The focusing throughput could reach up to ∼10 5 counts/min. Furthermore, its applicability to biological cells is also demonstrated by 3D focusing of HeLa and melanoma cells and bovine blood cells in the proposed microchannel. The proposed sheathless passive focusing scheme, featuring a simple channel structure, small footprint (9 mm × 1.2 mm), compact layout, and uncomplicated fabrication procedure, holds great promise as an efficient 3D focusing unit for the development of next-generation on-chip flow cytometry.

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

    Directory of Open Access Journals (Sweden)

    Elif Sarı


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

  4. A retrospective study comparing the outcome of horses undergoing small intestinal resection and anastomosis with a single layer (Lembert) or double layer (simple continuous and Cushing) technique. (United States)

    Close, Kristyn; Epstein, Kira L; Sherlock, Ceri E


    To (1) compare postoperative complications and survival in horses after small intestinal resection and anastomosis using 2 anastomosis techniques (single layer Lembert; double layer simple continuous oversewn with Cushing), and (2) to compare outcome by anastomosis type (jejunoileostomy; jejunojejunostomy). Retrospective case series. Horses (n = 53). Medical records (July 2006-July 2010) of all horses that had small intestinal resection and anastomosis. Horses were divided into groups based on technique and type of anastomosis. Comparisons of pre- and intraoperative findings (disease severity), postoperative complications, and survival rates were made between groups. There were no differences in disease severity, postoperative complications, or survival between single layer (n = 23) or double layer (n = 31) anastomoses. There were no differences in disease severity or survival between jejunoileostomy (n = 16) or jejunojejunostomy (n = 38). There was a higher incidence of postoperative colic in hospital after jejunoileostomy (13/16) compared with jejunojejunostomy (18/38) (P = .0127). Postoperative complications and survival are comparable between horses undergoing single layer and double layer small intestinal end-to-end anastomoses. With the exception of increased postoperative colic in the hospital, postoperative complications and survival after jejunoileostomy and jejunojejunostomy are also comparable. © Copyright 2014 by The American College of Veterinary Surgeons.

  5. Basic interrupted versus continuous suturing techniques in bronchial anastomosis following sleeve lobectomy in dogs. (United States)

    Bayram, Ahmet Sami; Erol, Mehmet Muharrem; Salci, Hakan; Ozyiğit, Ozgür; Görgül, Sacit; Gebitekin, Cengiz


    Sleeve resection with or without lung resection is a valid conservative operation for patients with benign or malignant tumors; it enables the preservation of lung parenchyma. The aim of this prospective randomized study was to compare complications, operating time, and bronchial healing between the techniques of interrupted and continuous suturing for bronchial anastomosis in dogs. Twenty adult mongrel dogs each weighing 18-22 kg (average: 20 kg) were divided into two groups according to the anastomosis technique performed: group A, interrupted suturing and group B, continuous suturing. Each group comprised of 10 dogs. Following right thoracotomy, sleeve resection of the right cranial lobe was performed in all dogs. Basic interrupted sutures using 4/0 Vicryl (Ethicon, USA) were used in group A, and continuous sutures were used in group B. The median anastomosis time was 15.2 min (range: 13-21 min) in group A and 9.6 min (range: 8-13 min) in group B. In all dogs, the anastomosis line was resected via right pneumonectomy for histopathological investigation 1 month after sleeve resection. Histopathological examination revealed that the healing of the anastomosis was not affected by the suturing technique applied. One dog from each group died on the fourth postoperative day; Fisher's exact test, p=0.763. Our research revealed that the healing of the anastomosis was not affected by the suturing technique performed.

  6. Single-Layer Plication for Repair of Diastasis Recti: The Most Rapid and Efficient Technique. (United States)

    Gama, Luiz José Muaccad; Barbosa, Marcus Vinicius Jardini; Czapkowski, Adriano; Ajzen, Sergio; Ferreira, Lydia Masako; Nahas, Fábio Xerfan


    Plication of the anterior rectus sheath is the most commonly used technique for repair of diastasis recti, but is also a time-consuming procedure. The aim of this study was to compare the efficacy and time required to repair diastasis recti using different plication techniques. Thirty women with similar abdominal deformities, who had had at least one pregnancy, were randomized into three groups to undergo abdominoplasty. Plication of the anterior rectus sheath was performed in two layers with 2-0 monofilament nylon suture (control group) or in a single layer with either a continuous 2-0 monofilament nylon suture (group I) or using a continuous barbed suture (group II). Operative time was recorded. All patients underwent ultrasound examination preoperatively and at 3 weeks and 6 months postoperatively to monitor for diastasis recurrence. The force required to bring the anterior rectus sheath to the midline was measured at the supraumbilical and infraumbilical levels. Patient age ranged from 26 to 50 years and body mass index from 20.56 to 29.17 kg/m2. A significant difference in mean operative time was found between the control and study groups (control group, 35 min:22 s; group I, 14 min:22 s; group II, 15 min:23 s; P < 0.001). Three patients in group II had recurrence of diastasis. There were no significant within- and between-group differences in tensile force on the aponeurosis. Plication of the anterior rectus sheath in a single-layer with a continuous suture showed to be an efficient and rapid technique for repair of diastasis recti. © 2017 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission:

  7. Single Layered Versus Double Layered Intestinal Anastomosis: A Randomized Controlled Trial (United States)

    Mohapatra, Vandana; Singh, Surendra; Rath, Pratap Kumar; Behera, Tapas Ranjan


    Introduction Gastrointestinal anastomosis is one of the most common procedures being performed in oesophagogastric, hepatobiliary, bariatric, small bowel and colorectal surgery; however, the safety and efficacy of single layer or double layer anastomotic technique is still unclear. Aim To assess and compare the efficacy, safety and cost effectiveness of single layered versus double layered intestinal anastomosis. Materials and Methods This prospective, double-blind, randomized controlled comparative study comprised of patients who underwent intestinal resection and anastomosis. They were randomly assigned to undergo either single layered extra-mucosal anastomosis (Group-A) or double layered intestinal anastomosis (Group-B). Primary outcome measures included average time taken for anastomosis, postoperative complications, mean duration of hospital stay and cost of suture material used; secondary outcome measures assessed the postoperative return of bowel function. Statistical analysis was done by Chi-square test and student t-test. Results A total of 97 participants were randomized. Fifty patients were allocated to single layered extramucosal continuous anastomosis (Group-A) and 47 patients to double layered anastomosis (Group-B). The patients in each group were well matched for age, sex and diagnosis. The mean time taken for anastomosis (15.12±2.27 minutes in Group-A versus 24.38±2.26 minutes in Group-B) and the length of hospital stay (5.90±1.43 days in Group-A versus 7.29±1.89 days in Group-B) was significantly shorter in Group-A {p-value anastomosis. However, there was no significant difference in the complication rates between the two groups. Conclusion It can be concluded that single layered extramucosal continuous intestinal anastomosis is equally safe and perhaps more cost effective than the conventional double layered method and may represent the optimal choice for routine surgical practice. PMID:28764239

  8. Comparison of a continuous suture pattern with a simple interrupted pattern for enteric closure in dogs and cats: 83 cases (1991-1997). (United States)

    Weisman, D L; Smeak, D D; Birchard, S J; Zweigart, S L


    To describe and compare a simple continuous suture pattern with a simple interrupted pattern for enterotomy closure or end-to-end intestinal anastomosis. Retrospective study. 58 dogs and 25 cats that underwent enterotomy or intestinal resection and anastomosis. Signalment, surgical procedure, suture pattern, suture material, confirmation of dehiscence, and follow-up were reviewed. Groups were compared by procedure (anastomosis or enterotomy) and by suture pattern. 57 animals underwent continuous closure; 26 had interrupted closure. Only polydioxanone or polypropylene suture materials were used. Overall, 81 (98%) animals had no signs of intestinal dehiscence and survived > 2 weeks. Two animals had confirmed dehiscence after foreign body removal, 1 of 57 (2%) after continuous closure, and 1 of 26 (4%) after interrupted closure. The simple continuous closure pattern is an acceptable alternative to simple interrupted closure for small intestinal anastomosis or enterotomy closure.

  9. Comparative study of hand sewn single layer anastomosis of dog's bowel Estudo comparativo das anastomoses manuais em plano único do intestino delgado de cães


    João Luiz Moreira Coutinho Azevedo; Octávio Hypólito; Otávio Cansanção Azevedo; Otávio Monteiro Becker Jr.; Dalmer Faria Freire


    BACKGROUND: Two-layer intestinal anastomosis increases the inflammatory response while single-layer anastomosis results in a better wound healing. However the four main kinds of stitches which may be chosen in performing single layer intestinal sutures never before had been comparatively studied. AIM: To compare the four more commonly used types of single layer surgical anastomosis sutures of the digestive tract. METHODS: Six mongrel dogs were operated, each one receiving two anastomosis: one...

  10. Técnicas de sutura do tubo digestivo em plano único total, em jejuno de cães: pontos de Gambee com nós atados na serosa versus pontos totais atados no lume, sobre a mucosa Single layer anastomosis of digestive tract with thru-and-thru sutures, in dogs: Gambee's stitch knotted under viscous surface, on serosa, versus simple stitch knotted inside the lumen, under mucosa

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    João Luiz Moreira Coutinho Azevedo


    Full Text Available OBJETIVO: Comparar a sutura do tubo digestivo em plano único com pontos totais simples versus pontos especiais de Gambee. MÉTODOS: Foram operados seis cães machos, sem raça definida, pesando entre 7 e 12 kg, anestesiados com pentobarbital sódico a 30 mg/kg. Foi realizada secção transversa do jejuno, a 30 cm da flexura duodenojejunal, seguida de anastomose término-terminal com a técnica de sutura em plano único total descrita por Gambee, sendo a metade anterior da anastomose suturada com nós atados na superfície serosa e a metade posterior com nós atados sobre a camada mucosa, no lume do órgão. Foram utilizados pontos simples separados de polipropileno monofilamentar azul 4-0, pré-montados em agulha de 2 cm (3/8 de círculo, intervalados de 3 mm. No 7º dia pós-operatório os animais foram sacrificados e necropsiados. Foram analisadas as aderências na linha de sutura mediante um escore e feita análise macroscópica e microscópica , inclusive histometria. RESULTADOS: As aderências peritoneais se equivaleram em ambas as faces da anastomose.O exame macroscópico da linha de sutura mostrou boa regeneração serosa. Na microscopia observava-se permanência de fenômenos inflamatórios agudos em ambas as suturas. O realinhamento, a reestruturação e a regeneração das camadas foram adequadas em todo o perímetro da anastomose. Na morfometria, os polimorfonucleares, os macrófagos, os fibroblastos e as fibras colágenas se equivaleram nas duas metades comparadas da anastomose. CONCLUSÃO: A reparação do tubo digestivo na região anastomótica em plano único total pela técnica de Gambee se faz de forma similar, quer tenham sido utilizados pontos de sutura especiais de Gambee ou pontos totais simples. Dessa forma, é indiferente a utilização de um ou de outro tipo de sutura aqui estudado, dependendo exclusivamente da preferência do cirurgião.PURPOSE: To compare two types of single layer thru-and-thru sutures of the digestive

  11. A comparison of simple continuous versus simple interrupted suture patterns for tracheal anastomosis after large-segment tracheal resection in dogs. (United States)

    Fingland, R B; Layton, C I; Kennedy, G A; Galland, J C


    Two suture techniques for tracheal anastomosis after large-segment tracheal resection were compared. Eight cartilages were resected from the trachea of each of 12 dogs; anastomoses with 4-0 polydioxanone suture were created using a simple continuous suture technique in six dogs and a simple interrupted suture technique in six dogs. Surgical time was shorter but apposition of tracheal segments at the time of surgery was less precise with the simple continuous suture technique. The dogs were evaluated for 150 days after surgery. Clinical abnormalities after tracheal resection and anastomosis were not observed. Percent dorsoventral luminal stenosis was calculated by measuring the tracheal lumen diameter on lateral cervical radiographs. Percent luminal stenosis was calculated planimetrically using a computerized digitizing tablet. Anastomotic stenosis was mild in all dogs; however, the mean percent.luminal stenosis determined planimetrically was significantly greater for dogs that had the simple continuous suture technique. Planimetric measurements of cross-sectional area made before and after formalin fixation were not significantly different. Radiographic determination of percent dorsoventral luminal stenosis was a poor predictor of diminution of cross-sectional area determined planimetrically.

  12. Experience with single-layer rectal anastomosis.


    Khubchandani, M; Upson, J


    Anastomotic dehiscence following resection of the large intestine is a serious complication. Satisfactory results of single-layer anastomosis depend upon meticulous technique and a scrupulously clean colon. Out of 65 single-layer anastomoses involving the rectum, significant leakage occurred in 4 patients. The results are reported in order to draw attention to the safety and efficacy of one-layer anastomosis.

  13. Interrupted versus continuous sutures for repair of episiotomy of 2nd degree perineal tears

    International Nuclear Information System (INIS)

    Aslam, R.; Khan, S.A.


    Performing an episiotomy is generally reserved for complicated childbirths, in cases of foetal distress, or when tearing of tissues with serious consequences are foreseen. In addition to the extent of the trauma, the surgical skill, repair after childbirth can have an important effect on the magnitude and degree of morbidity experienced by women after repair. The best technique for this repair would be that which produces less pain in the short and long term. The study was done with an objective to compare the frequency and severity of pain (slight/severe) by using interrupted and continuous methods for repair of episiotomy or second degree perineal tears.It is a randomized control trial. This study was carried out in a Gynaecology and Obstetrics department of Benazir Bhutto Hospital Rawalpindi which is a tertiary care hospital. The duration of study was six months. One hundred and thirty-eight primigravidas (69 in each group) were included in the study. Majority of the patients in both groups belonged to 20-25 years age group, i.e. 48.53 percentage (n=33) in group-A and 50 percentage (n=34) in group-B, mean and SD, was 27.69±3.21 in group-A and 28.16 ± 3.89 in group-B, gestation age of the patients in group-A 77.94 percentage (n=53) and 83.82 percentage (n=57) in group-B between 37-40 weeks of gestation. Complication of pain and its severity in both groups at 24 hours and 10th day were compared which showed no significant difference at any severity (i.e. no pain, mild moderate/severe). There is no significant difference in frequency and severity of pain (slight/severe) in using interrupted and continuous methods for repair of second degree perineal tears or episiotomy. (author)

  14. Suture Coding: A Novel Educational Guide for Suture Patterns. (United States)

    Gaber, Mohamed; Abdel-Wahed, Ramadan


    This study aims to provide a helpful guide to perform tissue suturing successfully using suture coding-a method for identification of suture patterns and techniques by giving full information about the method of application of each pattern using numbers and symbols. Suture coding helps construct an infrastructure for surgical suture science. It facilitates the easy understanding and learning of suturing techniques and patterns as well as detects the relationship between the different patterns. Guide points are fixed on both edges of the wound to act as a guideline to help practice suture pattern techniques. The arrangement is fixed as 1-3-5-7 and a-c-e-g on one side (whether right or left) and as 2-4-6-8 and b-d-f-h on the other side. Needle placement must start from number 1 or letter "a" and continue to follow the code till the end of the stitching. Some rules are created to be adopted for the application of suture coding. A suture trainer containing guide points that simulate the coding process is used to facilitate the learning of the coding method. (120) Is the code of simple interrupted suture pattern; (ab210) is the code of vertical mattress suture pattern, and (013465)²/3 is the code of Cushing suture pattern. (0A1) Is suggested as a surgical suture language that gives the name and type of the suture pattern used to facilitate its identification. All suture patterns known in the world should start with (0), (A), or (1). There is a relationship between 2 or more surgical patterns according to their codes. It can be concluded that every suture pattern has its own code that helps in the identification of its type, structure, and method of application. Combination between numbers and symbols helps in the understanding of suture techniques easily without complication. There are specific relationships that can be identified between different suture patterns. Coding methods facilitate suture patterns learning process. The use of suture coding can be a good

  15. Preliminary results with sutured colonic anastomoses reinforced with dye-enhanced fibrinogen and a diode laser (United States)

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


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

  16. Tunneling spin injection into single layer graphene. (United States)

    Han, Wei; Pi, K; McCreary, K M; Li, Yan; Wong, Jared J I; Swartz, A G; Kawakami, R K


    We achieve tunneling spin injection from Co into single layer graphene (SLG) using TiO₂ seeded MgO barriers. A nonlocal magnetoresistance (ΔR(NL)) of 130  Ω is observed at room temperature, which is the largest value observed in any material. Investigating ΔR(NL) vs SLG conductivity from the transparent to the tunneling contact regimes demonstrates the contrasting behaviors predicted by the drift-diffusion theory of spin transport. Furthermore, tunnel barriers reduce the contact-induced spin relaxation and are therefore important for future investigations of spin relaxation in graphene.

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

    LENUS (Irish Health Repository)

    Hennessey, D B


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

  18. Force sensing in surgical sutures.

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    Tim Horeman

    Full Text Available 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 4(th stitch was placed. During placement of the 5(th, 6(th and 7(th stitch, the force in the 2(nd 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.

  19. Force sensing in surgical sutures. (United States)

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


    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 4(th) stitch was placed. During placement of the 5(th), 6(th) and 7(th) stitch, the force in the 2(nd) 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.

  20. LENA Conversion Foils Using Single-Layer Graphene, Phase I (United States)

    National Aeronautics and Space Administration — Our key innovation will be the use of single-layer graphene as LENA conversion foils, with appropriate microgrids and nanogrids to support the foils. Phase I...

  1. Functionalization of Single Layer MoS$_2$ Honeycomb Structures


    Ataca, C.; Ciraci, S.


    Based on the first-principles plane wave calculations, we studied the functionalization of the two-dimensional single layer MoS$_2$ structure via adatom adsorption and vacancy defect creation. Minimum energy adsorption sites are determined for sixteen different adatoms, each gives rise to diverse properties. Bare, single layer MoS$_2$, which is normally a nonmagnetic, direct band gap semiconductor, attains a net magnetic moment upon adsorption of specific transition metal atoms, as well as si...

  2. Optimization of Single-Layer Braced Domes

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    Grzywiński Maksym


    Full Text Available The paper deals with discussion of optimization problem in civil engineering structural space design. Minimization of mass should satisfy the limit state capacity and serviceability conditions. The cross-sectional areas of bars and structural dimensions are taken as design variables. Variables are used in the form of continuous and discrete. The analysis is done using the Structural and Design of Experiments modules of Ansys Workbench v17.2. As result of the method a mass reduction of 46,6 % is achieved.

  3. Plasmon enhanced terahertz emission from single layer graphene. (United States)

    Bahk, Young-Mi; Ramakrishnan, Gopakumar; Choi, Jongho; Song, Hyelynn; Choi, Geunchang; Kim, Yong Hyup; Ahn, Kwang Jun; Kim, Dai-Sik; Planken, Paul C M


    We show that surface plasmons, excited with femtosecond laser pulses on continuous or discontinuous gold substrates, strongly enhance the generation and emission of ultrashort, broadband terahertz pulses from single layer graphene. Without surface plasmon excitation, for graphene on glass, 'nonresonant laser-pulse-induced photon drag currents' appear to be responsible for the relatively weak emission of both s- and p-polarized terahertz pulses. For graphene on a discontinuous layer of gold, only the emission of the p-polarized terahertz electric field is enhanced, whereas the s-polarized component remains largely unaffected, suggesting the presence of an additional terahertz generation mechanism. We argue that in the latter case, 'surface-plasmon-enhanced optical rectification', made possible by the lack of inversion symmetry at the graphene on gold surface, is responsible for the strongly enhanced emission. The enhancement occurs because the electric field of surface plasmons is localized and enhanced where the graphene is located: at the surface of the metal. We believe that our results point the way to small, thin, and more efficient terahertz photonic devices.

  4. Comparison of Knotless Barbed Suture Versus Monofilament Suture in the Oral Cavity of Cats. (United States)

    Durand, Corinne L


    The present study compares a knotless, barbed, absorbable suture material against a conventional monofilament absorbable suture material in oral mucosal wound closure. The parameters measured include time of closure and differences in healing at 2 and 4 weeks postoperatively. A prospective study comparing a knotless, barbed suture system with conventional absorbable sutures was undertaken in 19 cats. Nineteen cats had full mouth extractions performed. Following the extraction procedures, the incisions in the arcades (maxillary and mandibular) were apposed with the barbed, knotless suture system in a continuous pattern on one side and with a conventional smooth suture in an interrupted pattern on the other. Suturing times for each arcade were recorded. The material used to close the first side of each cat varied. Healing, dehiscence, and other complications were assessed at 2 and 4 weeks postoperatively. The average closure time (± standard deviation) per quadrant with conventional monofilament suture was 8.7 (±1.3) minutes, while barbed suture required an average of 5.1 (±1.1) minutes per quadrant to complete the suture. This difference (95% confidence interval) of 3.6 (±3.2-4.1) minutes per quadrant was statistically significant ( P < .001). Dehiscence and ranula-like swelling formation were noted as uncommon postoperative complications, but the differences were not significant between the groups. Barbed, knotless sutures resulted in faster closure times than conventional, simple interrupted, monofilament sutures with similar healing and complication rates. To the author's knowledge, there is no current literature comparing conventional absorbable monofilament sutures to a knotless, barbed, absorbable suture system for closure of oral mucosal incisions in cats.

  5. Single-layer graphene on silicon nitride micromembrane resonators

    DEFF Research Database (Denmark)

    Schmid, Silvan; Bagci, Tolga; Zeuthen, Emil


    for exciting new devices, such as optoelectromechanical transducers. Here, we add a single-layer graphene on SiN micromembranes and compare electromechanical coupling and mechanical properties to bare dielectric membranes and to membranes metallized with an aluminium layer. The electrostatic coupling...

  6. Kernel Function Tuning for Single-Layer Neural Networks

    Czech Academy of Sciences Publication Activity Database

    Vidnerová, Petra; Neruda, Roman

    -, accepted 28.11. 2017 (2018) ISSN 2278-0149 R&D Projects: GA ČR GA15-18108S Institutional support: RVO:67985807 Keywords : single-layer neural networks * kernel methods * kernel function * optimisation Subject RIV: IN - Informatics, Computer Science

  7. Breakwater stability with damaged single layer armour units

    NARCIS (Netherlands)

    De Rover, R.; Verhagen, H.J.; Van den Berge, A.; Reedijk, B.


    The effect of single layer interlocking armour unit breakage on the hydraulic armour layer stability and potential damage progression is addressed in this paper. A 2-dimensional scale model of a rubble mound breakwater with an armour layer consisting of Xbloc armour units was tested. The residual

  8. Automatic settlement analysis of single-layer armour layers

    NARCIS (Netherlands)

    Hofland, B.; van gent, Marcel


    A method to quantify, analyse, and present the settlement of single-layer concrete armour layers of coastal structures is presented. The use of the image processing technique for settlement analysis is discussed based on various modelling
    studies performed over the years. The accuracy of the

  9. Thermoelectric properties of single-layered SnSe sheet (United States)

    Wang, Fancy Qian; Zhang, Shunhong; Yu, Jiabing; Wang, Qian


    Motivated by the recent study of inspiring thermoelectric properties in bulk SnSe [Zhao et al., Nature, 2014, 508, 373] and the experimental synthesis of SnSe sheets [Chen et al., J. Am. Chem. Soc., 2013, 135, 1213], we have carried out systematic calculations for a single-layered SnSe sheet focusing on its stability, electronic structure and thermoelectric properties by using density functional theory combined with Boltzmann transport theory. We have found that the sheet is dynamically and thermally stable with a band gap of 1.28 eV, and the figure of merit (ZT) reaches 3.27 (2.76) along the armchair (zigzag) direction with optimal n-type carrier concentration, which is enhanced nearly 7 times compared to its bulk counterpart at 700 K due to quantum confinement effect. Furthermore, we designed four types of thermoelectric couples by assembling single-layered SnSe sheets with different transport directions and doping types, and found that their efficiencies are all above 13%, which are higher than those of thermoelectric couples made of commercial bulk Bi2Te3 (7%-8%), suggesting the great potential of single-layered SnSe sheets for heat-electricity conversion.Motivated by the recent study of inspiring thermoelectric properties in bulk SnSe [Zhao et al., Nature, 2014, 508, 373] and the experimental synthesis of SnSe sheets [Chen et al., J. Am. Chem. Soc., 2013, 135, 1213], we have carried out systematic calculations for a single-layered SnSe sheet focusing on its stability, electronic structure and thermoelectric properties by using density functional theory combined with Boltzmann transport theory. We have found that the sheet is dynamically and thermally stable with a band gap of 1.28 eV, and the figure of merit (ZT) reaches 3.27 (2.76) along the armchair (zigzag) direction with optimal n-type carrier concentration, which is enhanced nearly 7 times compared to its bulk counterpart at 700 K due to quantum confinement effect. Furthermore, we designed four types of

  10. Raman spectroscopy of boron-doped single-layer graphene. (United States)

    Kim, Yoong Ahm; Fujisawa, Kazunori; Muramatsu, Hiroyuki; Hayashi, Takuya; Endo, Morinobu; Fujimori, Toshihiko; Kaneko, Katsumi; Terrones, Mauricio; Behrends, Jan; Eckmann, Axel; Casiraghi, Cinzia; Novoselov, Kostya S; Saito, Riichiro; Dresselhaus, Mildred S


    The introduction of foreign atoms, such as nitrogen, into the hexagonal network of an sp(2)-hybridized carbon atom monolayer has been demonstrated and constitutes an effective tool for tailoring the intrinsic properties of graphene. Here, we report that boron atoms can be efficiently substituted for carbon in graphene. Single-layer graphene substitutionally doped with boron was prepared by the mechanical exfoliation of boron-doped graphite. X-ray photoelectron spectroscopy demonstrated that the amount of substitutional boron in graphite was ~0.22 atom %. Raman spectroscopy demonstrated that the boron atoms were spaced 4.76 nm apart in single-layer graphene. The 7-fold higher intensity of the D-band when compared to the G-band was explained by the elastically scattered photoexcited electrons by boron atoms before emitting a phonon. The frequency of the G-band in single-layer substitutionally boron-doped graphene was unchanged, which could be explained by the p-type boron doping (stiffening) counteracting the tensile strain effect of the larger carbon-boron bond length (softening). Boron-doped graphene appears to be a useful tool for engineering the physical and chemical properties of graphene.

  11. Bandgap tunability at single-layer molybdenum disulphide grain boundaries

    KAUST Repository

    Huang, Yu Li


    Two-dimensional transition metal dichalcogenides have emerged as a new class of semiconductor materials with novel electronic and optical properties of interest to future nanoelectronics technology. Single-layer molybdenum disulphide, which represents a prototype two-dimensional transition metal dichalcogenide, has an electronic bandgap that increases with decreasing layer thickness. Using high-resolution scanning tunnelling microscopy and spectroscopy, we measure the apparent quasiparticle energy gap to be 2.40±0.05 eV for single-layer, 2.10±0.05 eV for bilayer and 1.75±0.05 eV for trilayer molybdenum disulphide, which were directly grown on a graphite substrate by chemical vapour deposition method. More interestingly, we report an unexpected bandgap tunability (as large as 0.85±0.05 eV) with distance from the grain boundary in single-layer molybdenum disulphide, which also depends on the grain misorientation angle. This work opens up new possibilities for flexible electronic and optoelectronic devices with tunable bandgaps that utilize both the control of two-dimensional layer thickness and the grain boundary engineering.

  12. Cranial suture complexity in white-tailed deer (Odocoileus virginianus). (United States)

    Nicolay, Christopher W; Vaders, Mark J


    Neurocranial expansion and mastication are commonly implicated as the two major biomechanical factors affecting suture morphology. In deer the antlers provide an additional source of biomechanical stress acting on the skull. Equivalent stresses are not found in females, who lack antlers. We analyzed the complexity and interdigitation of the interfrontal and coronal sutures that surround the antler-bearing frontal bones of (n = 67) white-tailed deer (Odocoileus virginianus) to 1) evaluate changes in suture morphology throughout ontogeny, and 2) test the hypothesis that male deer have more complex sutures than females. Two methods were used to quantify suture morphology: fractal analysis and length-ratios (actual suture length divided by direct straightline length). Both techniques produced similar results, although the two methods cannot be considered equivalent. Suture complexity increases markedly throughout ontogeny, but appears to level off after animals have reached adulthood. Cranial size in males, but not females, continues to increase in adults. No significant increase in suture complexity with age in the adult cohort was detected. While deer are highly dimorphic in size and the presence of antlers, no significant differences existed between males and females for any measure of suture complexity. No consistent patterns emerged between suture complexity and skull size or antler characteristics. The presence of antlers appears to have a minimal effect on suture complexity in white-tailed deer. Factors that may contribute to the lack of dimorphism in suture complexity are discussed. (c) 2006 Wiley-Liss, Inc.

  13. Suture materials and suture techniques used in tendon repair. (United States)

    Ketchum, L D


    . The less traumatic suture techniques facilitate closure of the tendon sheath, which not only acts as a mechanical barrier to the ingrowth of extrasheath adhesion, which produces fibroblasts, but also re-establishes the continuity of the synovial fluid system, which is a major source of nutrition to the tendon. The healing tendon then can be thought of as a delicate structure, one not to be overmanipulated, traumatized, strangulated, or stretched.(ABSTRACT TRUNCATED AT 400 WORDS)

  14. [Single-layer colonic anastomoses using polyglyconate (Maxon) vs. two-layer anastomoses using chromic catgut and silk. Experimental study]. (United States)

    García-Osogobio, Sandra Minerva; Takahashi-Monroy, Takeshi; Velasco, Liliana; Gaxiola, Miguel; Sotres-Vega, Avelina; Santillán-Doherty, Patricio


    The safety of an intestinal anastomosis is usually measured by its complication rate, especially the incidence of anastomotic leakage. A wide variety of methods have been described to reestablish intestinal continuity including single-layer continuous or two-layer interrupted anastomosis. To evaluate if the single-layer continuous anastomosis using polygluconate is safer and reliable than two-layer interrupted anastomosis with chromic catgut and silk. A prospective, experimental, randomized and comparative analysis was conducted in 20 dogs. They were divided in two groups; group 1 underwent two-layer interrupted anastomosis and group 2 underwent sigle-layer continuous technique. Anastomoses were timed. Both groups were under observation. Anastomotic leakage, and other complications were evaluated. The animals were sacrified and the anastomosis was taken out together with 10 cm of colon on both sides of the anastomosis. Breaking strength, histologic evaluation and hydroxyproline determination were performed. Ten two-layer anastomosis and ten single-layer anastomosis were performed. A median of 25 minutes (range: 20-30 minutes) was required to construct the anastomoses in group 1 versus 20 minutes (range: 12-25 minutes) in group 2. All animals survived and no leakage was observed. Wound infection ocurred in four dogs (20%). Median breaking strength was 230 mm Hg in group 1 and 210 mm Hg in group 2. Hydroxyproline concentration was 8.94 mg/g in group 1 (range: 5.33-16.71) and 9.94 mg/g in group 2 (range: 2.96-21.87). There was no difference among groups about the inflammatory response evaluated by pathology. There was no statistical significance in any variable evaluated. CONCLUIONS: This study demonstrates that a single-layer continuous is similar in terms of safety to the two-layer technique, but because of its facility to perform, the single-layer technique could be superior.

  15. Midwives conducting perineal repair: The Danish Suture Trial

    DEFF Research Database (Denmark)

    Kindberg, Sara


    haemorrhage >1000 ml, Diabetes, mental disorders. Both suture techniques were 2-layered using a polyglactin 910 multifilament suture (Vicryl Rapid or Vicryl). Treatment A was a continuous suture technique and treatment B was interrupted, inverted stitches. Primary outcomes: Perineal pain and wound healing......Midwives conducting perineal repair: The Danish Suture Trial.     Background Suture techniques and materials for repair of 2nd degree perineal lacerations and episiotomies have been tested in several clinical trials. Danish midwives and obstetricians have developed a new, simple and time......-efficient suture technique which needed systematic evaluation. Objective To compare two standardized suture techniques for perineal repair of 2nd degree perineal lacerations or episiotomies. Design and setting A double-blind randomised clinical trial conducted in Aarhus University Hospital, Denmark. Initiated...

  16. Single-layer MoS2 transistors. (United States)

    Radisavljevic, B; Radenovic, A; Brivio, J; Giacometti, V; Kis, A


    Two-dimensional materials are attractive for use in next-generation nanoelectronic devices because, compared to one-dimensional materials, it is relatively easy to fabricate complex structures from them. The most widely studied two-dimensional material is graphene, both because of its rich physics and its high mobility. However, pristine graphene does not have a bandgap, a property that is essential for many applications, including transistors. Engineering a graphene bandgap increases fabrication complexity and either reduces mobilities to the level of strained silicon films or requires high voltages. Although single layers of MoS(2) have a large intrinsic bandgap of 1.8 eV (ref. 16), previously reported mobilities in the 0.5-3 cm(2) V(-1) s(-1) range are too low for practical devices. Here, we use a halfnium oxide gate dielectric to demonstrate a room-temperature single-layer MoS(2) mobility of at least 200 cm(2) V(-1) s(-1), similar to that of graphene nanoribbons, and demonstrate transistors with room-temperature current on/off ratios of 1 × 10(8) and ultralow standby power dissipation. Because monolayer MoS(2) has a direct bandgap, it can be used to construct interband tunnel FETs, which offer lower power consumption than classical transistors. Monolayer MoS(2) could also complement graphene in applications that require thin transparent semiconductors, such as optoelectronics and energy harvesting.


    Directory of Open Access Journals (Sweden)



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

  18. Suture midface suspension

    Directory of Open Access Journals (Sweden)

    Murthy Rachna


    Full Text Available Abstract Objective To describe a simple and effective facelift technique useful as an adjunct to other oculoplastic procedures Methods Retrospective, non-comparative case series. Thirty five patients undergoing suture midface suspension from 1998 to 2000. Suspension sutures were passed from the nasolabial fold to the temporalis fascia to elevate the midface and the corner of the mouth. Results A satisfactory and stable outcome is obtained in 2 years of follow up. Conclusion Suture midface suspension is a safe and effective technique for the management of midface descent.

  19. Single-layer graphene on silicon nitride micromembrane resonators

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Silvan; Guillermo Villanueva, Luis; Amato, Bartolo; Boisen, Anja [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, 2800 Kongens Lyngby (Denmark); Bagci, Tolga; Zeuthen, Emil; Sørensen, Anders S.; Usami, Koji; Polzik, Eugene S. [QUANTOP, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen (Denmark); Taylor, Jacob M. [Joint Quantum Institute/NIST, College Park, Maryland 20899 (United States); Herring, Patrick K.; Cassidy, Maja C. [School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts 02138 (United States); Marcus, Charles M. [Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen (Denmark); Cheol Shin, Yong; Kong, Jing [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)


    Due to their low mass, high quality factor, and good optical properties, silicon nitride (SiN) micromembrane resonators are widely used in force and mass sensing applications, particularly in optomechanics. The metallization of such membranes would enable an electronic integration with the prospect for exciting new devices, such as optoelectromechanical transducers. Here, we add a single-layer graphene on SiN micromembranes and compare electromechanical coupling and mechanical properties to bare dielectric membranes and to membranes metallized with an aluminium layer. The electrostatic coupling of graphene covered membranes is found to be equal to a perfectly conductive membrane, without significantly adding mass, decreasing the superior mechanical quality factor or affecting the optical properties of pure SiN micromembranes. The concept of graphene-SiN resonators allows a broad range of new experiments both in applied physics and fundamental basic research, e.g., for the mechanical, electrical, or optical characterization of graphene.

  20. Single-layer and integrated YBCO gradiometer coupled SQUIDs

    Energy Technology Data Exchange (ETDEWEB)

    Baer, L.R.; Daalmans, G.M.; Barthel, K.H.; Ferchland, L.; Selent, M.; Kuehnl, M.; Uhl, D. [Siemens AG, Central Research and Development, Paul-Gossen-Strasse 100, D-91052 Erlangen (Germany)


    For many SQUID applications such as biomagnetism or non-destructive evaluation it is convenient or even necessary to work without the restrictions of a magnetically shielded room. This contribution deals with two sensors appropriate for this purpose. In the first concept we present a flip chip arrangement of a single-layer flux transformer and a single-layer SQUID, taking advantage of a simple technology. The SQUID was prepared on a 15x15 mm{sup 2} SrTiO{sub 3} 24 deg. bicrystal and located in the common line of two-parallel-loop arrangements. The flipped antenna was designed as a two-parallel-loop gradiometer with 26 mm baseline on a 10x40 mm{sup 2} LaAlO{sub 3} single-crystal substrate. A field gradient sensitivity of 1 nT cm{sup -1}{phi}{sub 0} was obtained. We could demonstrate a field gradient resolution of 20 fT cm{sup -1} Hz{sup 1/2} at 1 kHz in an unshielded environment. In the second concept we integrated both the flux antenna and the SQUID on a SrTiO{sub 3} bicrystal. The tighter coupling scheme results in smaller devices for similar field gradient sensitivities. The integrated SQUID is designed as a 3x8 mm{sup 2} device on a 10x10 mm{sup 2} bicrystal substrate. The remaining space is used for test structures and SQUIDs without antennae, in order to control the technology as well as the SQUID design. Parallel processed dummy substrates were used to monitor the quality of film growth by x-ray analysis. The quality of our SQUID design will be discussed on the basis of the measured field gradient sensitivity and noise. The reliability of the devices is demonstrated by an NDE type measurement. (author)

  1. Charge transferred doping of single layer graphene by mono-dispersed manganese-oxide nanoparticles adsorption (United States)

    Phan, Thanh Luan; Kang, Myunggoo; Choi, Soo Ho; Kim, You Joong; Jung, Hyun; Yoon, Im Taek; Yang, Woochul


    We report an efficient and controllable method to introduce p-type doping in graphene by decoration with Mn3O4 nanoparticles (NPs) on mechanically exfoliated single layer graphene. A monolayer of Mn3O4 NPs, with a diameter in the range of 5-10 nm, was decorated on a graphene film using an ex-situ method, whereas by controlling the coverage of the NPs on the graphene surface, the carrier concentration could be continually adjusted. The p-type of the NP-decorated single layer graphene was confirmed by the Raman G-band. It was found that the carrier concentration could be gradually adjusted up to 26.09 × 1012 cm-2, with 90% coverage of Mn3O4 NPs. The Dirac point of the pristine graphene at the gate bias of 27 V shifted to 150 V for Mn3O4 NP decorated graphene. The p-type graphene doped with Mn3O4 NPs demonstrated significant high air-stability, even under an oxygen atmosphere for 60 days. This approach allows for the opportunity for simple, scalable, and highly stable doping of graphene for future high-performance electronic device applications.

  2. Touch stimulated pulse generation in biomimetic single-layer graphene (United States)

    Sul, Onejae; Chun, Hyunsuk; Choi, Eunseok; Choi, Jungbong; Cho, Kyeongwon; Jang, Dongpyo; Chun, Sungwoo; Park, Wanjun; Lee, Seung-Beck


    Detecting variation in contact pressure is a separate sensing mode in the human somatosensory system that differs from the detection of pressure magnitude. If pressure magnitude and variation sensing can be achieved simultaneously, an advanced biomimetic tactile system that better emulates human senses may be developed. We report on a novel single-layer graphene based artificial mechanoreceptor that generates a resistance pulse as the contact stimulus passes a specific threshold pressure, mimicking the generation of action potentials in a biological fast-adapting mechanoreceptor. The electric field from a flexible membrane gate electrode placed above a graphene channel raises the Fermi level from the valence band as pressure deflects the membrane. The threshold pressure is reached when the Fermi level crosses the Dirac point in the graphene energy band, which generates a sharp peak in the measured resistance. We found that by changing the gate potential it was possible to modulate the threshold pressure and using a series of graphene channels, a train of pulses were generated during a transient pressurizing stimulus demonstrating biomimetic behaviour.Detecting variation in contact pressure is a separate sensing mode in the human somatosensory system that differs from the detection of pressure magnitude. If pressure magnitude and variation sensing can be achieved simultaneously, an advanced biomimetic tactile system that better emulates human senses may be developed. We report on a novel single-layer graphene based artificial mechanoreceptor that generates a resistance pulse as the contact stimulus passes a specific threshold pressure, mimicking the generation of action potentials in a biological fast-adapting mechanoreceptor. The electric field from a flexible membrane gate electrode placed above a graphene channel raises the Fermi level from the valence band as pressure deflects the membrane. The threshold pressure is reached when the Fermi level crosses the Dirac

  3. Electrical and optical transport properties of single layer WSe2 (United States)

    Tahir, M.


    The electronic properties of single layer WSe2 are distinct from the famous graphene due to strong spin orbit coupling, a huge band gap and an anisotropic lifting of the degeneracy of the valley degree of freedom under Zeeman field. In this work, band structure of the monolayer WSe2 is evaluated in the presence of spin and valley Zeeman fields to study the electrical and optical transport properties. Using Kubo formalism, an explicit expression for the electrical Hall conductivity is examined at finite temperatures. The electrical longitudinal conductivity is also evaluated. Further, the longitudinal and Hall optical conductivities are analyzed. It is observed that the contributions of the spin-up and spin-down states to the power absorption spectrum depend on the valley index. The numerical results exhibit absorption peaks as a function of photon energy, ℏ ω, in the range ∼ 1.5 -2 eV. Also, the optical response lies in the visible frequency range in contrast to the conventional two-dimensional electron gas or graphene where the response is limited to terahertz regime. This ability to isolate carriers in spin-valley coupled structures may make WSe2 a promising candidate for future spintronics, valleytronics and optical devices.

  4. Intrinsic Charge Carrier Mobility in Single-Layer Black Phosphorus. (United States)

    Rudenko, A N; Brener, S; Katsnelson, M I


    We present a theory for single- and two-phonon charge carrier scattering in anisotropic two-dimensional semiconductors applied to single-layer black phosphorus (BP). We show that in contrast to graphene, where two-phonon processes due to the scattering by flexural phonons dominate at any practically relevant temperatures and are independent of the carrier concentration n, two-phonon scattering in BP is less important and can be considered negligible at n≳10^{13}  cm^{-2}. At smaller n, however, phonons enter in the essentially anharmonic regime. Compared to the hole mobility, which does not exhibit strong anisotropy between the principal directions of BP (μ_{xx}/μ_{yy}∼1.4 at n=10^{13} cm^{-2} and T=300  K), the electron mobility is found to be significantly more anisotropic (μ_{xx}/μ_{yy}∼6.2). Absolute values of μ_{xx} do not exceed 250 (700)  cm^{2} V^{-1} s^{-1} for holes (electrons), which can be considered as an upper limit for the mobility in BP at room temperature.

  5. Synthesis of PbI(2) single-layered inorganic nanotubes encapsulated within carbon nanotubes. (United States)

    Cabana, Laura; Ballesteros, Belén; Batista, Eudar; Magén, César; Arenal, Raúl; Oró-Solé, Judith; Rurali, Riccardo; Tobias, Gerard


    The template assisted growth of single-layered inorganic nanotubes is reported. Single-crystalline lead iodide single-layered nanotubes have been prepared using the inner cavities of carbon nanotubes as hosting templates. The diameter of the resulting inorganic nanotubes is merely dependent on the diameter of the host. This facile method is highly versatile opening up new horizons in the preparation of single-layered nanostructures. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Novel doping alternatives for single-layer transition metal dichalcogenides (United States)

    Onofrio, Nicolas; Guzman, David; Strachan, Alejandro


    Successful doping of single-layer transition metal dichalcogenides (TMDs) remains a formidable barrier to their incorporation into a range of technologies. We use density functional theory to study doping of molybdenum and tungsten dichalcogenides with a large fraction of the periodic table. An automated analysis of the energetics, atomic and electronic structure of thousands of calculations results in insightful trends across the periodic table and points out promising dopants to be pursued experimentally. Beyond previously studied cases, our predictions suggest promising substitutional dopants that result in p-type transport and reveal interesting physics behind the substitution of the metal site. Doping with early transition metals (TMs) leads to tensile strain and a significant reduction in the bandgap. The bandgap increases and strain is reduced as the d-states are filled into the mid TMs; these trends reverse as we move into the late TMs. Additionally, the Fermi energy increases monotonously as the d-shell is filled from the early to mid TMs and we observe few to no gap states, indicating the possibility of both p- (early TMs) and n- (mid TMs) type doping. Quite surprisingly, the simulations indicate the possibility of interstitial doping of TMDs; the energetics reveal that a significant number of dopants, increasing in number from molybdenum disulfide to diselenide and to ditelluride, favor the interstitial sites over adsorbed ones. Furthermore, calculations of the activation energy associated with capturing the dopants into the interstitial site indicate that the process is kinetically possible. This suggests that interstitial impurities in TMDs are more common than thought to date and we propose a series of potential interstitial dopants for TMDs relevant for application in nanoelectronics based on a detailed analysis of the predicted electronic structures.

  7. Single-layer HDR video coding with SDR backward compatibility (United States)

    Lasserre, S.; François, E.; Le Léannec, F.; Touzé, D.


    The migration from High Definition (HD) TV to Ultra High Definition (UHD) is already underway. In addition to an increase of picture spatial resolution, UHD will bring more color and higher contrast by introducing Wide Color Gamut (WCG) and High Dynamic Range (HDR) video. As both Standard Dynamic Range (SDR) and HDR devices will coexist in the ecosystem, the transition from Standard Dynamic Range (SDR) to HDR will require distribution solutions supporting some level of backward compatibility. This paper presents a new HDR content distribution scheme, named SL-HDR1, using a single layer codec design and providing SDR compatibility. The solution is based on a pre-encoding HDR-to-SDR conversion, generating a backward compatible SDR video, with side dynamic metadata. The resulting SDR video is then compressed, distributed and decoded using standard-compliant decoders (e.g. HEVC Main 10 compliant). The decoded SDR video can be directly rendered on SDR displays without adaptation. Dynamic metadata of limited size are generated by the pre-processing and used to reconstruct the HDR signal from the decoded SDR video, using a post-processing that is the functional inverse of the pre-processing. Both HDR quality and artistic intent are preserved. Pre- and post-processing are applied independently per picture, do not involve any inter-pixel dependency, and are codec agnostic. Compression performance, and SDR quality are shown to be solidly improved compared to the non-backward and backward-compatible approaches, respectively using the Perceptual Quantization (PQ) and Hybrid Log Gamma (HLG) Opto-Electronic Transfer Functions (OETF).

  8. Water desalination with a single-layer MoS2 nanopore (United States)

    Heiranian, Mohammad; Farimani, Amir Barati; Aluru, Narayana R.


    Efficient desalination of water continues to be a problem facing the society. Advances in nanotechnology have led to the development of a variety of nanoporous membranes for water purification. Here we show, by performing molecular dynamics simulations, that a nanopore in a single-layer molybdenum disulfide can effectively reject ions and allow transport of water at a high rate. More than 88% of ions are rejected by membranes having pore areas ranging from 20 to 60 Å2. Water flux is found to be two to five orders of magnitude greater than that of other known nanoporous membranes. Pore chemistry is shown to play a significant role in modulating the water flux. Pores with only molybdenum atoms on their edges lead to higher fluxes, which are ∼70% greater than that of graphene nanopores. These observations are explained by permeation coefficients, energy barriers, water density and velocity distributions in the pores. PMID:26465062

  9. Improving the light-emitting properties of single-layered polyfluorene light-emitting devices by simple ionic liquid blending (United States)

    Horike, Shohei; Nagaki, Hiroto; Misaki, Masahiro; Koshiba, Yasuko; Morimoto, Masahiro; Fukushima, Tatsuya; Ishida, Kenji


    This paper describes an evaluation of ionic liquids (ILs) as potential electrolytes for single-layered light-emitting devices with good emission performance. As optoelectronic devices continue to grow in abundance, high-performance light-emitting devices with a single emission layer are becoming increasingly important for low-cost production. We show that a simple technique of osmosing IL into the polymer layer can result in high luminous efficiency and good response times of single-layered light-emitting polymers, even without the additional stacking of charge carrier injection and transport layers. The IL contributions to the light-emission of the polymer are discussed from the perspectives of energy diagrams and of the electric double layers on the electrodes. Our findings enable a faster, cheaper, and lower-in-waste production of light-emitting devices.

  10. Experimental research on the stability of armour and secondary layer in a single layered Tetrapod breakwater

    NARCIS (Netherlands)

    De Jong, W.; Verhagen, H.J.; Olthof, J.


    Physical model tests were done on an armour of Tetrapods, placed in a single layer. The objective of the investigations was to study the stability of the secondary layer, and to see if the material of this secondary layer could be washed out through the single layer of Tetrapods. It was concluded

  11. A theoretical study of pump–probe experiment in single-layer ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 82; Issue 6. A theoretical study of pump–probe experiment in single-layer, bilayer and multilayer graphene ... Here we use it as a tool to study the phenomenon of anomalous Rabi oscillations in graphene that was predicted recently in single-layer graphene.

  12. Replacement for sutures. (United States)


    Davis and Geek has introduced a blue tissue adhesive, Histoacryl, for use as a gentle alternative to stitches for children who need treatment for minor skin wounds. The company says that accident and emergency departments have found it provides an excellent alternative to sutures because there is no need for an anaesthetic nor a return visit to have the stitches removed. It takes away some of the trauma for the young patients and parents as well as the staff who treat them.

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

    Directory of Open Access Journals (Sweden)

    Nelson Leonardo Kerdahi Leite de Campos


    Full Text Available OBJETIVO: Observar o comportamento da sutura arterial em aortas abdominais de coelhos em crescimento, comparando-se as técnicas contínua e com pontos separados, empregando-se dois tipos de fios: Polipropilene 7-0 (inabsorvível e Polidioxanone 7-0 (absorvível. MÉTODOS: Grupos: GI - Controle (sem sutura; GII - Polipropilene, Pontos Separados; GIII - Polipropilene, Contínua; GIV - Polidioxanone, Pontos Separados e GV - Polidioxanone, Contínua. Cada grupo foi subdividido em quatro Momentos de Eutanásia: aos 7, 14, 30 e 60 dias de pós-operatório. Foram avaliados: peso dos animais, diâmetros e pulsos arteriais, estenose, trombose, aderências, aortografia, visibilidade do fio, cicatrização e microscopia. RESULTADOS: a após 60 dias, o local da linha de sutura cresceu de forma significativa em todos os grupos; b a técnica de sutura com pontos separados causou menor estenose da linha de sutura, observada tanto no ato cirúrgico, como na eutanásia dos animais; c no exame histopatológico, as diferenças encontradas entre grupos foram transitórias, não persistindo após 60 dias de pós-operatório. CONCLUSÃO: O polidioxanone mostrou ser a melhor opção, entre os dois fios, para sutura de artérias em crescimento, pois causa pouca ou nenhuma restrição ao crescimento arterial na linha de sutura, mesmo quando se emprega a técnica contínua.PURPOSE: To assess the arterial suture, comparing continuous and interrupted techniques, in abdominal aorta of growing rabbbits, using two types of suture material: Polypropylene 7-0 (nonabsorbable and Polydioxanone 7-0 (absorbable. METHODS: Groups: GI - Control, without arterial suture; GII - Polypropylene, Interrupted technique; GIII - Polipropilene, Continuous technique; GIV - Polydioxanone, Interrupted technique and GV - Polydioxanone, Continuous technique. Each group was subdivided in four Moments of Euthanasia , according with the number of days after surgery: 7 , 14 , 30 and 60 days. The

  14. Single-layer Ultralight, Flexible, Shielding Tension Shell System for Extreme Heat and Radiation (United States)

    National Aeronautics and Space Administration — The objective of this project is to develop a flexible thermal protection system (FTPS) with a Boron Nitride Nanotube (BNNT)-based single-layer, lightweight,...

  15. Hydraulic Stability of Single-Layer Dolos and Accropode Armour Layers

    DEFF Research Database (Denmark)

    Christensen, M.; Burcharth, H. F.


    A new design for Dolos breakwater armour layers is presented: Dolos armour units are placed in a selected geometric pattern in a single layer. A series of model tests have been performed in order to determine the stability of such single-layer Dolos armour layers. The test results are presented...... and compared to the stability formula for the traditional double-layer, randomly placed Dolos armour layer design presented by Burcharth (1992). The results of a series of stability tests performed with Accropode® armour layers is presented and compared to the test results obtained with single-layer Dolos...... armour layers. Run-up and reflection are presented for both single-layer Dolos armour and Accropode armour....

  16. The Efficacy of Polydioxanone Monofilament Absorbable Suture for Tracheal Anastomosis


    Kawahara, Katsunobu; Yamasaki, Naoya; Yamamoto, Satoshi; Nagayasu, Takeshi; Kusano, Hiroyuki; Akamine, Shinji; Takahashi, Takao; Tomita, Masao


    To evaluate the efficacy of polydioxanon absorbable suture for tracheal anastomoses, we performed an experimental study using dose. Eight adult mongrel dogs underwent sleeve resection of the mediastinal trachea. A length of ten to twelve cartilage rings was resected. An end-to-end anastomosis was performed using either interrupted or continuous running 4-0 polydioxanone (PDS) suture. There was no detectable difference bronchoscopically, microangiografically, or histologically, in tracheal ana...

  17. Force sensing in surgical sutures

    NARCIS (Netherlands)

    T. Horeman (Tim); E.-J. Meijer (Evert-Jan); J.J. Harlaar (Joris Jan); J.F. Lange (Johan); J.J. van den Dobbelsteen (John); J. Dankelman (Jenny)


    textabstractThe tension in a suture is an important factor in the process of wound healing. If there is too much tension in the suture, the blood flow is restricted and necrosis can occur. If the tension is too low, the incision opens up and cannot heal properly. The purpose of this paper is to

  18. Force sensing in surgical sutures

    NARCIS (Netherlands)

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


    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

  19. Single track and single layer formation in selective laser melting of niobium solid solution alloy

    Directory of Open Access Journals (Sweden)

    Yueling GUO


    Full Text Available Selective laser melting (SLM was employed to fabricate Nb-37Ti-13Cr-2Al-1Si (at% alloy, using pre-alloyed powders prepared by plasma rotating electrode processing (PREP. A series of single tracks and single layers under different processing parameters was manufactured to evaluate the processing feasibility by SLM, including laser power, scanning speed, and hatch distance. Results showed that continuous single tracks could be fabricated using proper laser powers and scanning velocities. Both the width of a single track and its penetration depth into a substrate increased with an increase of the linear laser beam energy density (LED, i.e., an increase of the laser power and a decrease of the scanning speed. Nb, Ti, Si, Cr, and Al elements distributed heterogeneously over the melt pool in the form of swirl-like patterns. An excess of the hatch distance was not able to interconnect neighboring tracks. Under improper processing parameters, a balling phenomenon occurred, but could be eliminated with an increased LED. This work testified the SLM-processing feasibility of Nb-based alloy and promoted the application of SLM to the manufacture of niobium-based alloys. Keywords: Additive manufacturing, Melt pool, Niobium alloy, Powder metallurgy, Selective laser melting

  20. Meso-Tethyan oceanic sutures and their deformation (United States)

    Burtman, V. S.


    On the basis of comparative stratigraphie and paleontologic analysis, supported by some key paleomagnetic data and interpretations, it is shown that during the Mesozoic and the Cenozoic the Eurasian continent grew by accretion of microcontinents. These microcontinents separated basins with oceanic crust from the main ocean. During the Late Cretaceous and the early Cenozoic the collision of the microcontinents with Eurasia resulted in the closure of the basins, and Meso-Tethyan oceanic sutures originated. In the region under consideration, from the Carpathians to Tibet, there are two main Meso-Tethyan sutures: the Carpathian-Lesser Caucasus and the Afghan-Tibet suture. The above-mentioned main structures also had branches, which remained as sutures of small basins: the Kamennopotock, Interpontide, Nain-Baft basins and others. In the West Carpathians the Carpathian-Lesser Caucasus suture is overlain by a widespread Gemeric-Tatric allochton. From the West Carpathians the suture passes through the Pannonian basin into the Vardar ophiolite zone and farther to the ophiolites of the Izmir-Ankara zone. Being displaced along the North Anatolian right-lateral strike-slip fault, the main suture passes from the Eastern Pontides into the Lesser Caucasus, where it is marked by ophiolites of the Amasia area, the Shirak, Bozum and Zangezur ridges. Sunsequently, it can be observed through the Iranian Qara Dagh mountains to Lake Urumiyeh and the North Anatolian strike-slip fault. Being again shifted along the strike-slip fault, the Carpathian-Lesser Caucasus Meso-Tethyan suture ends in the Western Zagros near the Cenozoic Neo-Tethyan suture. The Afghan-Tibet Meso-Tethyan suture is situated in the Pamirs in the Rushan-Pshart zone. The east prolongation of the suture has been displaced along the Pamir-Karakorum right-lateral strike-slip fault in Tibet. West of the Pamirs this suture is also displaced along strike-slip faults and continues in the Farahrud zone in Afghanistan, and than

  1. Two Techniques of Intestinal Wall Suture in Surgical Treatment of Ileus in Dogs and the Importance of Omentalisation

    Directory of Open Access Journals (Sweden)

    M. Crha


    Full Text Available Model experimental studies focused on the intestinal suture techniques in relation to healing, postoperative narrowing of the intestinal lumen or adhesion formation can not comprise a number of clinical factors (foreign body presence in the intestine, haematological abnormalities, septic peritonitis, different age of patients, etc. that under clinical practice conditions may have an effect on the healing of the intestinal suture. The aim of this clinical study was to confirm in a group of dogs surgically treated for small bowel obstruction, whether different techniques of its wall suture may affect the frequency of possible dehiscence occurrence. This study compares two different techniques of intestinal wall suture in relation to postoperative dehiscence of the intestinal wall closure. Based on the clinical observation with regard to the risk of postoperative dehiscence and possible complications in form of adhesions, also the importance of omentalisation in the suture of small bowel was evaluated. No significant difference was demonstrated (p > 0.05 in the frequency of postoperative dehiscence at the site of the intestinal wall closure between the two-layer inverting and singlelayer appositional techniques of suture. Likewise, no significant difference was demonstrated (p > 0.05 in the frequency of dehiscence of intestinal wall suture between patients that underwent intestinal suture omentalisation and those whose intestinal wall suture was not complemented with omentalisation. Based on the results of this clinical study it may be stated that both manual single-layer approximation technique and two-layer inverting technique of the intestinal wall suture are equally safe from the viewpoint of possible dehiscence, and it depends on the surgeon's preference, which one of the said techniques he or she chooses. Concurrently it may be assumed that an exactly performed suture of the intestinal wall does not necessarily require omentalisation.

  2. Diverse and tunable electronic structures of single-layer metal phosphorus trichalcogenides for photocatalytic water splitting

    International Nuclear Information System (INIS)

    Liu, Jian; Li, Xi-Bo; Wang, Da; Liu, Li-Min; Lau, Woon-Ming; Peng, Ping


    The family of bulk metal phosphorus trichalcogenides (APX 3 , A = M II , M 0.5 I M 0.5 III ; X = S, Se; M I , M II , and M III represent Group-I, Group-II, and Group-III metals, respectively) has attracted great attentions because such materials not only own magnetic and ferroelectric properties, but also exhibit excellent properties in hydrogen storage and lithium battery because of the layered structures. Many layered materials have been exfoliated into two-dimensional (2D) materials, and they show distinct electronic properties compared with their bulks. Here we present a systematical study of single-layer metal phosphorus trichalcogenides by density functional theory calculations. The results show that the single layer metal phosphorus trichalcogenides have very low formation energies, which indicates that the exfoliation of single layer APX 3 should not be difficult. The family of single layer metal phosphorus trichalcogenides exhibits a large range of band gaps from 1.77 to 3.94 eV, and the electronic structures are greatly affected by the metal or the chalcogenide atoms. The calculated band edges of metal phosphorus trichalcogenides further reveal that single-layer ZnPSe 3 , CdPSe 3 , Ag 0.5 Sc 0.5 PSe 3 , and Ag 0.5 In 0.5 PX 3 (X = S and Se) have both suitable band gaps for visible-light driving and sufficient over-potentials for water splitting. More fascinatingly, single-layer Ag 0.5 Sc 0.5 PSe 3 is a direct band gap semiconductor, and the calculated optical absorption further convinces that such materials own outstanding properties for light absorption. Such results demonstrate that the single layer metal phosphorus trichalcogenides own high stability, versatile electronic properties, and high optical absorption, thus such materials have great chances to be high efficient photocatalysts for water-splitting

  3. Morphology and atomic-scale structure of single-layer WS2 nanoclusters. (United States)

    Füchtbauer, Henrik G; Tuxen, Anders K; Moses, Poul G; Topsøe, Henrik; Besenbacher, Flemming; Lauritsen, Jeppe V


    Two-dimensional sheets of transition metal (Mo and W) sulfides are attracting strong attention due to the unique electronic and optical properties associated with the material in its single-layer form. The single-layer MoS2 and WS2 are already in widespread commercial use in catalytic applications as both hydrotreating and hydrocracking catalysts. Consequently, characterization of the morphology and atomic structure of such particles is of utmost importance for the understanding of the catalytic active phase. However, in comparison with the related MoS2 system only little is known about the fundamental properties of single-layer WS2 (tungstenite). Here, we use an interplay of atom-resolved Scanning Tunneling Microscopy (STM) studies of Au(111)-supported WS2 nanoparticles and calculated edge structures using Density Functional Theory (DFT) to reveal the equilibrium morphology and prevalent edge structures of single-layer WS2. The STM results reveal that the single layer S-W-S sheets adopt a triangular equilibrium shape under the sulfiding conditions of the synthesis, with fully sulfided edges. The predominant edge structures are determined to be the (101[combining macron]0) W-edge, but for the smallest nanoclusters also the (1[combining macron]010) S-edges become important. DFT calculations are used to construct phase diagrams of the WS2 edges, and describe their sulfur and hydrogen coordination under different conditions, and in this way shed light on the catalytic role of WS2 edges.

  4. Selective exfoliation of single-layer graphene from non-uniform graphene grown on Cu

    International Nuclear Information System (INIS)

    Lim, Jae-Young; Lee, Jae-Hyun; Jang, Hyeon-Sik; Whang, Dongmok; Joo, Won-Jae; Hwang, SungWoo


    Graphene growth on a copper surface via metal-catalyzed chemical vapor deposition has several advantages in terms of providing high-quality graphene with the potential for scale-up, but the product is usually inhomogeneous due to the inability to control the graphene layer growth. The non-uniform regions strongly affect the reliability of the graphene in practical electronic applications. Herein, we report a novel graphene transfer method that allows for the selective exfoliation of single-layer graphene from non-uniform graphene grown on a Cu foil. Differences in the interlayer bonding energy are exploited to mechanically separate only the top single-layer graphene and transfer this to an arbitrary substrate. The dry-transferred single-layer graphene showed electrical characteristics that were more uniform than those of graphene transferred using conventional wet-etching transfer steps. (paper)

  5. Fabrication of a single layer graphene by copper intercalation on a SiC(0001) surface

    International Nuclear Information System (INIS)

    Yagyu, Kazuma; Tochihara, Hiroshi; Tomokage, Hajime; Suzuki, Takayuki; Tajiri, Takayuki; Kohno, Atsushi; Takahashi, Kazutoshi


    Cu atoms deposited on a zero layer graphene grown on a SiC(0001) substrate, intercalate between the zero layer graphene and the SiC substrate after the thermal annealing above 600 °C, forming a Cu-intercalated single layer graphene. On the Cu-intercalated single layer graphene, a graphene lattice with superstructure due to moiré pattern is observed by scanning tunneling microscopy, and specific linear dispersion at the K ¯ point as well as a characteristic peak in a C 1s core level spectrum, which is originated from a free-standing graphene, is confirmed by photoemission spectroscopy. The Cu-intercalated single layer graphene is found to be n-doped

  6. Single layer of Ge quantum dots in HfO2for floating gate memory capacitors. (United States)

    Lepadatu, A M; Palade, C; Slav, A; Maraloiu, A V; Lazanu, S; Stoica, T; Logofatu, C; Teodorescu, V S; Ciurea, M L


    High performance trilayer memory capacitors with a floating gate of a single layer of Ge quantum dots (QDs) in HfO 2 were fabricated using magnetron sputtering followed by rapid thermal annealing (RTA). The layer sequence of the capacitors is gate HfO 2 /floating gate of single layer of Ge QDs in HfO 2 /tunnel HfO 2 /p-Si wafers. Both Ge and HfO 2 are nanostructured by RTA at moderate temperatures of 600-700 °C. By nanostructuring at 600 °C, the formation of a single layer of well separated Ge QDs with diameters of 2-3 nm at a density of 4-5 × 10 15 m -2 is achieved in the floating gate (intermediate layer). The Ge QDs inside the intermediate layer are arranged in a single layer and are separated from each other by HfO 2 nanocrystals (NCs) about 8 nm in diameter with a tetragonal/orthorhombic structure. The Ge QDs in the single layer are located at the crossing of the HfO 2 NCs boundaries. In the intermediate layer, besides Ge QDs, a part of the Ge atoms is segregated by RTA at the HfO 2 NCs boundaries, while another part of the Ge atoms is present inside the HfO 2 lattice stabilizing the tetragonal/orthorhombic structure. The fabricated capacitors show a memory window of 3.8 ± 0.5 V and a capacitance-time characteristic with 14% capacitance decay in the first 3000-4000 s followed by a very slow capacitance decrease extrapolated to 50% after 10 years. This high performance is mainly due to the floating gate of a single layer of well separated Ge QDs in HfO 2 , distanced from the Si substrate by the tunnel oxide layer with a precise thickness.

  7. Thermal vibration of a rectangular single-layered graphene sheet with quantum effects

    International Nuclear Information System (INIS)

    Wang, Lifeng; Hu, Haiyan


    The thermal vibration of a rectangular single-layered graphene sheet is investigated by using a rectangular nonlocal elastic plate model with quantum effects taken into account when the law of energy equipartition is unreliable. The relation between the temperature and the Root of Mean Squared (RMS) amplitude of vibration at any point of the rectangular single-layered graphene sheet in simply supported case is derived first from the rectangular nonlocal elastic plate model with the strain gradient of the second order taken into consideration so as to characterize the effect of microstructure of the graphene sheet. Then, the RMS amplitude of thermal vibration of a rectangular single-layered graphene sheet simply supported on an elastic foundation is derived. The study shows that the RMS amplitude of the rectangular single-layered graphene sheet predicted from the quantum theory is lower than that predicted from the law of energy equipartition. The maximal relative difference of RMS amplitude of thermal vibration appears at the sheet corners. The microstructure of the graphene sheet has a little effect on the thermal vibrations of lower modes, but exhibits an obvious effect on the thermal vibrations of higher modes. The quantum effect is more important for the thermal vibration of higher modes in the case of smaller sides and lower temperature. The relative difference of maximal RMS amplitude of thermal vibration of a rectangular single-layered graphene sheet decreases monotonically with an increase of temperature. The absolute difference of maximal RMS amplitude of thermal vibration of a rectangular single-layered graphene sheet increases slowly with the rising of Winkler foundation modulus.

  8. The history of barbed sutures. (United States)

    Ruff, Gregory L


    Ligatures have been used for millennia to close wounds. Sterilization and synthetic polymers that degrade in a commensurate fashion with wound healing have been the most significant improvements in these age-old devices. However, the constricting loop of a traditional suture and subsequent ischemia ("approximate, don't strangulate") still account for the most common cause of wound dehiscence-necrosis. Inspired by the quill of the North American porcupine, I envisioned a bidirectional array of barbs that could secure tissue without relying on constricting loops. One set of barbs could anchor the other. In this article, I document the development process of these barbed sutures from concept to patent to manufacture and US Food and Drug Administration approval. Knotless, strong, and easy to place, barbed sutures could foreseeably supplant conventional sutures, particularly as endoscopic procedures become more common. They also offer the intriguing potential to suspend ptotic tissues without surgical intervention.

  9. Chemical etching of copper foils for single-layer graphene growth by chemical vapor deposition (United States)

    Yoshihara, Naoki; Noda, Masaru


    Chemical etching on copper surface is essential as a pre-treatment for single-layer graphene growth by chemical vapor deposition (CVD). Here, we investigated the effect of chemical etching treatment on copper foils for single-layer graphene CVD growth. The chemical etching conditions, such as the type of chemical etchants and the treatment time, were found to strongly influence the graphene domain size. Moreover, a drastic change in the layer structure of graphene sheets, which was attributed to the surface morphology of the etched copper foil, was confirmed by graphene transmittance and Raman mapping measurements.

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

    Directory of Open Access Journals (Sweden)

    Swati R Yedke


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

  11. Evaluation of a novel suture material for closure of intestinal anastomoses in canine cadavers. (United States)

    Hansen, Lane A; Monnet, Eric L


    To compare leakage and maximum intraluminal pressures for a novel suture material with pressures for comparable suture material when used in closure of intestinal anastomoses in canine cadavers. Healthy intestines from cadavers of dogs euthanized for reasons unrelated to the study. 18 anastomoses were performed on intestinal sections within 72 hours after dogs were euthanized and intestinal samples collected. Anastomoses were performed with a simple continuous suture pattern. Leakage and maximum intraluminal pressures were measured and recorded for 6 control segments and 18 anastomosed sections. A barbed glycomer 631 suture (size 4-0 United States Pharmacopeia [USP]) was compared with glycomer 631 sutures (sizes 3-0 and 4-0 USP). Results for leakage and maximum intraluminal pressures were compared via an ANOVA. The barbed glycomer 631 suture material leaked at a significantly higher pressure than did the comparable glycomer 631 suture materials. Maximum intraluminal pressures were not significantly different among the suture materials. Barbed glycomer 631 4-0 USP suture material was as effective as glycomer 631 suture materials and may be a safe alternative for use in closure of enterectomies in dogs.

  12. Use of a barbed suture for laparoscopic closure of the internal inguinal rings in a horse. (United States)

    Ragle, Claude A; Yiannikouris, Stavros; Tibary, Ahmed A; Fransson, Boel A


    A 4-year-old castrated Arabian horse was evaluated for a history of a right-sided nonstrangulating inguinal hernia that was manually reducable. Physical examination revealed a right-sided hydrocele and bilateral enlargement of the inguinal rings detectable by both external digital and rectal palpation. Biportal laparoscopic internal inguinal ring closure was performed with a continuous suture line of unidirectional barbed suture applied with a mechanical suturing instrument. The barbed suture contributed to a secure closure with the added benefit of not requiring knots to be tied at either the beginning or end of the suture line. Follow-up physical examination and laparoscopy confirmed healing of the surgical sites and a reduction in size of the inguinal rings. The horse exercised for 20 months following surgery without recurrence of the inguinal hernia. In horses, laparoscopic application of unidirectional barbed sutures should be considered among the treatment options for recurrent inguinal herniation. This technique was accomplished with only 2 portals/side, in contrast to the additional 3 to 4 portals that are most commonly required. The use of a barbed suture with a mechanical suturing instrument offered added security to the closure. The difficulties of dual instrument suturing and intracorporeal knot tying were eliminated, dramatically reducing the challenges of performing suture reduction of the internal inguinal ring.

  13. Modeling of 1-D nitrate transport in single layer soils | Dike | Journal ...

    African Journals Online (AJOL)

    The transport of nitrate in laboratory single soil columns of sand, laterite and clay were investigated after 21 days. The 1-D contaminant transport model by Notodarmojo et al (1991) for single layer soils were calibrated and verified using field data collected from a refuse dump site at avu, owerri, Imo state. The experimental ...

  14. Single-layer skull approximations perform well in transcranial direct current stimulation modeling

    NARCIS (Netherlands)

    Rampersad, S.M.; Stegeman, D.F.; Oostendorp, T.F.


    In modeling the effect of transcranial direct current stimulation, the representation of the skull is an important factor. In a spherical model, we compared a realistic skull modeling approach, in which the skull consisted of three isotropic layers, to anisotropic and isotropic single-layer

  15. Diffusion of Supercritical Fluids through Single-Layer Nanoporous Solids: Theory and Molecular Simulations. (United States)

    Oulebsir, Fouad; Vermorel, Romain; Galliero, Guillaume


    With the advent of graphene material, membranes based on single-layer nanoporous solids appear as promising devices for fluid separation, be it liquid or gaseous mixtures. The design of such architectured porous materials would greatly benefit from accurate models that can predict their transport and separation properties. More specifically, there is no universal understanding of how parameters such as temperature, fluid loading conditions, or the ratio of the pore size to the fluid molecular diameter influence the permeation process. In this study, we address the problem of pure supercritical fluids diffusing through simplified models of single-layer porous materials. Basically, we investigate a toy model that consists of a single-layer lattice of Lennard-Jones interaction sites with a slit gap of controllable width. We performed extensive equilibrium and biased molecular dynamics simulations to document the physical mechanisms involved at the molecular scale. We propose a general constitutive equation for the diffusional transport coefficient derived from classical statistical mechanics and kinetic theory, which can be further simplified in the ideal gas limit. This transport coefficient relates the molecular flux to the fluid density jump across the single-layer membrane. It is found to be proportional to the accessible surface porosity of the single-layer porous solid and to a thermodynamic factor accounting for the inhomogeneity of the fluid close to the pore entrance. Both quantities directly depend on the potential of mean force that results from molecular interactions between solid and fluid atoms. Comparisons with the simulations data show that the kinetic model captures how narrowing the pore size below the fluid molecular diameter lowers dramatically the value of the transport coefficient. Furthermore, we demonstrate that our general constitutive equation allows for a consistent interpretation of the intricate effects of temperature and fluid loading

  16. Postpartum perineal reapir performed by midwives: A randomised trial comparing two suture techniques for perineal repair leaving the skin unsutured

    DEFF Research Database (Denmark)

    Kindberg, Sara; Misan, Stehouwer; Hvidman, Lone


    healing, patient satisfaction, dyspareunia or need for resuturing. The continuous suture technique was significantly faster (15 min. vs. 17 min, p=0.03) and less suture material was used (1 vs. 2 packets, pleaving the skin unsutured...... appears to be equivalent to the continuous suture technique in relation to perineal pain, wound healing, patient satisfaction, dyspareunia and need for resuturing. The continuous technique, however, is faster and requires less suture material thus leaving it the more cost-effective of the two techniques......Postpartum perineal repair performed by midwives: A randomised trial comparing two suture techniques leaving the skin unsutured. Objective      To compare a continuous suture technique to interrupted stitches using inverted knots for postpartum perineal repair of second-degree lacerations...

  17. A learning rule for very simple universal approximators consisting of a single layer of perceptrons. (United States)

    Auer, Peter; Burgsteiner, Harald; Maass, Wolfgang


    One may argue that the simplest type of neural networks beyond a single perceptron is an array of several perceptrons in parallel. In spite of their simplicity, such circuits can compute any Boolean function if one views the majority of the binary perceptron outputs as the binary output of the parallel perceptron, and they are universal approximators for arbitrary continuous functions with values in [0,1] if one views the fraction of perceptrons that output 1 as the analog output of the parallel perceptron. Note that in contrast to the familiar model of a "multi-layer perceptron" the parallel perceptron that we consider here has just binary values as outputs of gates on the hidden layer. For a long time one has thought that there exists no competitive learning algorithm for these extremely simple neural networks, which also came to be known as committee machines. It is commonly assumed that one has to replace the hard threshold gates on the hidden layer by sigmoidal gates (or RBF-gates) and that one has to tune the weights on at least two successive layers in order to achieve satisfactory learning results for any class of neural networks that yield universal approximators. We show that this assumption is not true, by exhibiting a simple learning algorithm for parallel perceptrons - the parallel delta rule (p-delta rule). In contrast to backprop for multi-layer perceptrons, the p-delta rule only has to tune a single layer of weights, and it does not require the computation and communication of analog values with high precision. Reduced communication also distinguishes our new learning rule from other learning rules for parallel perceptrons such as MADALINE. Obviously these features make the p-delta rule attractive as a biologically more realistic alternative to backprop in biological neural circuits, but also for implementations in special purpose hardware. We show that the p-delta rule also implements gradient descent-with regard to a suitable error measure

  18. High Throughput Characterization of Epitaxially Grown Single-Layer MoS2

    Directory of Open Access Journals (Sweden)

    Foad Ghasemi


    Full Text Available The growth of single-layer MoS2 with chemical vapor deposition is an established method that can produce large-area and high quality samples. In this article, we investigate the geometrical and optical properties of hundreds of individual single-layer MoS2 crystallites grown on a highly-polished sapphire substrate. Most of the crystallites are oriented along the terraces of the sapphire substrate and have an area comprised between 10 µm2 and 60 µm2. Differential reflectance measurements performed on these crystallites show that the area of the MoS2 crystallites has an influence on the position and broadening of the B exciton while the orientation does not influence the A and B excitons of MoS2. These measurements demonstrate that differential reflectance measurements have the potential to be used to characterize the homogeneity of large-area chemical vapor deposition (CVD-grown samples.

  19. Edge structures and properties of triangular antidots in single-layer MoS2

    KAUST Repository

    Gan, Li Yong


    Density functional theory and experiments are employed to shed light on the edge structures of antidots in O etched single-layer MoS2. The equilibrium morphology is found to be the zigzag Mo edge with each Mo atom bonded to two O atoms, in a wide range of O chemical potentials. Scanning electron microscopy shows that the orientation of the created triangular antidots is opposite to the triangular shape of the single-layer MoS2 samples, in agreement with the theoretical predictions. Furthermore, edges induced by O etching turn out to be p-doped, suggesting an effective strategy to realize p-type MoS2 devices. Published by AIP Publishing.

  20. Quantum Hall states of atomic Bose gases: Density profiles in single-layer and multilayer geometries

    International Nuclear Information System (INIS)

    Cooper, N. R.; Lankvelt, F. J. M. van; Reijnders, J. W.; Schoutens, K.


    We describe the density profiles of confined atomic Bose gases in the high-rotation limit, in single-layer and multilayer geometries. We show that, in a local-density approximation, the density in a single layer shows a landscape of quantized steps due to the formation of incompressible liquids, which are analogous to fractional quantum Hall liquids for a two-dimensional electron gas in a strong magnetic field. In a multilayered setup we find different phases, depending on the strength of the interlayer tunneling t. We discuss the situation where a vortex lattice in the three-dimensional condensate (at large tunneling) undergoes quantum melting at a critical tunneling t c 1 . For tunneling well below t c 1 one expects weakly coupled or isolated layers, each exhibiting a landscape of quantum Hall liquids. After expansion, this gives a radial density distribution with characteristic features (cusps) that provide experimental signatures of the quantum Hall liquids

  1. White-light-emitting diode based on a single-layer polymer (United States)

    Wang, B. Z.; Zhang, X. P.; Liu, H. M.


    A broad-band light-emitting diode was achieved in a single-layer device based on pure poly(9,9'-dioctylfluorene-co-bis-N,N'-(4-butylphenyl)-bis-N,N'-phenyl-1,4-phenylenediamine) (PFB). Electromer emission was observed in the red with a center wavelength of about 620 nm in electroluminescence (EL) spectrum. This kind of emission exhibits strong dependence on the thickness of the PFB layer, so that the shape of the EL spectrum may be adjusted through changing the thickness of the active polymer layer to balance between the intrinsic PFB emission in the blue and the electromer emission in the red. Thus, white light emission may be achieved from such a single-layer single-material diode.

  2. Edge structures and properties of triangular antidots in single-layer MoS{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Gan, Li-Yong, E-mail:, E-mail:, E-mail: [Key Laboratory of Advanced Technology of Materials (Ministry of Education), Superconductivity and New Energy R& D Center, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, Yingchun, E-mail:, E-mail:, E-mail:; Huang, Wei [Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials - SICAM, Nanjing Tech University - NanjingTech, 30 South Puzhu Road, Nanjing 211816 (China); Schwingenschlögl, Udo, E-mail:, E-mail:, E-mail: [Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia); Yao, Yingbang [Advanced Nanofabrication and Imaging Core Lab, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia); School of Materials and Energy, Guangdong University of Technology, Guangdong 510006 (China); Zhao, Yong [Key Laboratory of Advanced Technology of Materials (Ministry of Education), Superconductivity and New Energy R& D Center, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Physical Science and Technology, Southwest Jiaotong University, Chengdu, 610031 Sichuan (China); Zhang, Xi-xiang [Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia); Advanced Nanofabrication and Imaging Core Lab, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia)


    Density functional theory and experiments are employed to shed light on the edge structures of antidots in O etched single-layer MoS{sub 2}. The equilibrium morphology is found to be the zigzag Mo edge with each Mo atom bonded to two O atoms, in a wide range of O chemical potentials. Scanning electron microscopy shows that the orientation of the created triangular antidots is opposite to the triangular shape of the single-layer MoS{sub 2} samples, in agreement with the theoretical predictions. Furthermore, edges induced by O etching turn out to be p-doped, suggesting an effective strategy to realize p-type MoS{sub 2} devices.

  3. Persistent Charge-Density-Wave Order in Single-Layer TaSe2. (United States)

    Ryu, Hyejin; Chen, Yi; Kim, Heejung; Tsai, Hsin-Zon; Tang, Shujie; Jiang, Juan; Liou, Franklin; Kahn, Salman; Jia, Caihong; Omrani, Arash A; Shim, Ji Hoon; Hussain, Zahid; Shen, Zhi-Xun; Kim, Kyoo; Min, Byung Il; Hwang, Choongyu; Crommie, Michael F; Mo, Sung-Kwan


    We present the electronic characterization of single-layer 1H-TaSe 2 grown by molecular beam epitaxy using a combined angle-resolved photoemission spectroscopy, scanning tunneling microscopy/spectroscopy, and density functional theory calculations. We demonstrate that 3 × 3 charge-density-wave (CDW) order persists despite distinct changes in the low energy electronic structure highlighted by the reduction in the number of bands crossing the Fermi energy and the corresponding modification of Fermi surface topology. Enhanced spin-orbit coupling and lattice distortion in the single-layer play a crucial role in the formation of CDW order. Our findings provide a deeper understanding of the nature of CDW order in the two-dimensional limit.

  4. Interactions between C and Cu atoms in single-layer graphene: direct observation and modelling. (United States)

    Kano, Emi; Hashimoto, Ayako; Kaneko, Tomoaki; Tajima, Nobuo; Ohno, Takahisa; Takeguchi, Masaki


    Metal doping into the graphene lattice has been studied recently to develop novel nanoelectronic devices and to gain an understanding of the catalytic activities of metals in nanocarbon structures. Here we report the direct observation of interactions between Cu atoms and single-layer graphene by transmission electron microscopy. We document stable configurations of Cu atoms in the graphene sheet and unique transformations of graphene promoted by Cu atoms. First-principles calculations based on density functional theory reveal a reduction of energy barrier that caused rotation of C-C bonds near Cu atoms. We discuss two driving forces, electron irradiation and in situ heating, and conclude that the observed transformations were mainly promoted by electron irradiation. Our results suggest that individual Cu atoms can promote reconstruction of single-layer graphene.

  5. Identification of excitons, trions and biexcitons in single-layer WS{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Plechinger, Gerd; Nagler, Philipp; Kraus, Julia; Paradiso, Nicola; Strunk, Christoph; Schueller, Christian; Korn, Tobias [Institut fuer Experimentelle und Angewandte Physik, Universitaet Regensburg, 93040, Regensburg (Germany)


    Single-layer WS{sub 2} is a direct-gap semiconductor showing strong excitonic photoluminescence features in the visible spectral range. Here, we present temperature-dependent photoluminescence measurements on mechanically exfoliated single-layer WS{sub 2}, revealing the existence of neutral and charged excitons at low temperatures as well as at room temperature. By applying a gate voltage, we can electrically control the ratio of excitons and trions and assert a residual n-type doping of our samples. At high excitation densities and low temperatures, an additional peak at energies below the trion dominates the photoluminescence, which we identify as biexciton emission. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Phonon-limited mobility in n-type single-layer MoS2 from first principles

    DEFF Research Database (Denmark)

    Kaasbjerg, Kristen; Thygesen, Kristian S.; Jacobsen, Karsten W.


    We study the phonon-limited mobility in intrinsic n-type single-layer MoS2 for temperatures T > 100 K. The materials properties including the electron-phonon interaction are calculated from first principles and the deformation potentials and Frohlich interaction in single-layer MoS2 are establish...

  7. Initial experience with application of single layer modified Kugel mesh for inguinal hernia repair: Case series of 72 consecutive patients

    Directory of Open Access Journals (Sweden)

    Pao-Hwa Chen


    Conclusion: The postoperative complication and recurrence rates of single-layer MK mesh herniorrhaphy was comparable with previously reported tension-free repair. Single-layer application is safe and feasible. A longer follow-up period and larger study group with a control group are needed to verify our method.

  8. Model for a collimated spin wave beam generated by a single layer, spin torque nanocontact


    Hoefer, M. A.; Silva, T. J.; Stiles, M. D.


    A model of spin torque induced magnetization dynamics based upon semi-classical spin diffusion theory for a single layer nanocontact is presented. The model incorporates effects due to the current induced Oersted field and predicts the generation of a variety of spatially dependent, coherent, precessional magnetic wave structures. Directionally controllable collimated spin wave beams, vortex spiral waves, and localized standing waves are found to be excited by the interplay of the Oersted fie...

  9. Doping-controlled phase transitions in single-layer MoS2 (United States)

    Zhuang, Houlong L.; Johannes, Michelle D.; Singh, Arunima K.; Hennig, Richard G.


    The electronic properties of single-layer MoS2 make it an ideal two-dimensional (2D) material for application in electronic devices. Experiments show that MoS2 can undergo structural phase transitions. Applications of single-layer MoS2 will require firm laboratory control over the phase formation. Here we compare the stability and electronic structure of the three experimentally observed single-layer MoS2 phases, 2 H ,1 T , and 1 T' , and an in-plane metal/semiconductor heterostructure. We reveal by density-functional theory calculations that charge doping can induce the phase transition of single-layer MoS2 from the 2 H to the 1 T structure. Further, the 1 T structure undergoes a second phase transition due to the occurrence of a charge-density wave (CDW). By comparing the energies of several possible resulting CDW structures, we find that the 1 T' orthorhombic structure is the most stable one, consistent with experimental observations and previous theoretical studies. We show that the underlying CDW transition mechanism is not due to Fermi surface nesting, but nonetheless, can be controlled by charge doping. In addition, the stability landscape is highly sensitive to charge doping, which can be used as a practical phase selector. We also provide a prescription for obtaining the 1 T' structure via growth or deposition of MoS2 on a Hf substrate, which transfers electrons uniformly and with minimal structural distortion. Finally, we show that lateral heterostructures formed by the 2 H and 1 T' structures exhibit a low interfacial energy of 0.17 eV/Å, a small Schottky barrier of 0.3 eV for holes, and a large barrier of 1.6 eV for electrons.

  10. Growth of high-crystalline, single-layer hexagonal boron nitride on recyclable platinum foil. (United States)

    Kim, Gwangwoo; Jang, A-Rang; Jeong, Hu Young; Lee, Zonghoon; Kang, Dae Joon; Shin, Hyeon Suk


    Hexagonal boron nitride (h-BN) is gaining significant attention as a two-dimensional dielectric material, along with graphene and other such materials. Herein, we demonstrate the growth of highly crystalline, single-layer h-BN on Pt foil through a low-pressure chemical vapor deposition method that allowed h-BN to be grown over a wide area (8 × 25 mm(2)). An electrochemical bubbling-based method was used to transfer the grown h-BN layer from the Pt foil onto an arbitrary substrate. This allowed the Pt foil, which was not consumed during the process, to be recycled repeatedly. The UV-visible absorption spectrum of the single-layer h-BN suggested an optical band gap of 6.06 eV, while a high-resolution transmission electron microscopy image of the same showed the presence of distinct hexagonal arrays of B and N atoms, which were indicative of the highly crystalline nature and single-atom thickness of the h-BN layer. This method of growing single-layer h-BN over large areas was also compatible with use of a sapphire substrate.

  11. Learning rate and attractor size of the single-layer perceptron

    International Nuclear Information System (INIS)

    Singleton, Martin S.; Huebler, Alfred W.


    We study the simplest possible order one single-layer perceptron with two inputs, using the delta rule with online learning, in order to derive closed form expressions for the mean convergence rates. We investigate the rate of convergence in weight space of the weight vectors corresponding to each of the 14 out of 16 linearly separable rules. These vectors follow zigzagging lines through the piecewise constant vector field to their respective attractors. Based on our studies, we conclude that a single-layer perceptron with N inputs will converge in an average number of steps given by an Nth order polynomial in (t/l), where t is the threshold, and l is the size of the initial weight distribution. Exact values for these averages are provided for the five linearly separable classes with N=2. We also demonstrate that the learning rate is determined by the attractor size, and that the attractors of a single-layer perceptron with N inputs partition R N +R N

  12. Laser-assisted fabrication of single-layer flexible touch sensor (United States)

    Son, Seokwoo; Park, Jong Eun; Lee, Joohyung; Yang, Minyang; Kang, Bongchul


    Single-layer flexible touch sensor that is designed for the indium-tin-oxide (ITO)-free, bendable, durable, multi-sensible, and single layer transparent touch sensor was developed via a low-cost and one-step laser-induced fabrication technology. To this end, an entirely novel approach involving material, device structure, and even fabrication method was adopted. Conventional metal oxides based multilayer touch structure was substituted by the single layer structure composed of integrated silver wire networks of sensors and bezel interconnections. This structure is concurrently fabricated on a glass substitutive plastic film via the laser-induced fabrication method using the low-cost organometallic/nanoparticle hybrid complex. In addition, this study addresses practical solutions to heterochromia and interference problem with a color display unit. As a result, a practical touch sensor is successfully demonstrated through resolving the heterochromia and interference problems with color display unit. This study could provide the breakthrough for early realization of wearable device.

  13. [Laparoscopic suture or open suture in perforated duodenal ulcer]. (United States)

    Nicolau, A E; Ionescu, G; Iordache, F; Mehic, R; Spătaru, A


    Between Nov. 1994-Jan. 2001 we performed laparoscopic suture with omentoplasty of perforated duodenal ulcer (PDU) in 51 patients out of 56 it was intended (this constituted the laparoscopic group--LG). The selection criteria were young patients, age < 40 years, no associated diseases, onset of the operation under 12 hours from the occurrence of the perforation, absence of clear ulcer history. In the same period, we performed an open suture based on the same criteria in 105 patients (open group--OP). The results showed a difference between needed analgesia (2.8 days for LG vs. 5.2 days for OG) and a hospital stay of 6.1 days in LG vs. 7.7 days in OG. The incidence of postoperative complications was 5.88% in the LG and 7.61% in the OG with 1.96% and respective 1.90% reoperation rate. In conclusion laparoscopic suture of PDU with associated postoperative modern therapy of ulcer disease could be the treatment of choice in young patients.

  14. Triclosan sutures for surgical site infection in colorectal cancer. (United States)

    Yamashita, Kanefumi; Takeno, Shinsuke; Hoshino, Seiichiro; Shiwaku, Hironari; Aisu, Naoya; Yoshida, Yoichiro; Tanimura, Syu; Yamashita, Yuichi


    Among all procedures, surgical site infections (SSIs) in colorectal surgery continue to have the highest rate, accounting for 5%-45%. To prevent the bacterial colonization of suture material, which disables local mechanisms of wound decontamination, triclosan-coated sutures were developed. We assessed the effectiveness of triclosan-coated sutures used for skin closure on the rate of SSIs in colorectal cancer surgery. Until August 2012, we used conventional methods for skin closure in colorectal cancer surgery at the Department of Gastroenterological Surgery, Fukuoka University Faculty of Medicine. Therefore, for the control group, we retrospectively collected surveillance data over a 1.5-y period. From September 2012, we began using triclosan-coated polydioxanone antimicrobial sutures (PDS plus) for skin and fascia closure. Hence, we collected data for the study group from September 2012 to October 2013. Differences in baseline characteristics and selection bias were adjusted using the propensity score-matching method. A total of 399 patients who underwent colorectal surgery were included in this study. There were 214 patients in the control group and 185 patients in the study group. Baseline patient characteristics were similar between the propensity score-matched groups. The incidence of SSIs was less in the study group. Multivariate logistic regression analysis showed that the site of the procedure, laparoscopic surgery, and using triclosan-coated sutures remained the independent predictors of SSIs. The use of triclosan-coated sutures was advantageous for decreasing the risk of SSIs after colorectal surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Single-layer centrifugation through colloid selects improved quality of epididymal cat sperm. (United States)

    Chatdarong, K; Thuwanut, P; Morrell, J M


    The objectives were to determine the: 1) extent of epithelial and red blood cell contamination in epididymal cat sperm samples recovered by the cutting method; 2) efficacy of simple washing, single-layer centrifugation (SLC), and swim-up for selecting epididymal cat sperm; and 3) effects of freezing and thawing on cat sperm selected by various techniques. Ten unit samples were studied; each contained sperm from the cauda epididymides of four cats (total, approximately 200 x 10(6) sperm) and was equally allocated into four treatments: 1) simple washing, 2) single-layer centrifugation through colloid prior to cryopreservation (SLC-PC), 3) single-layer centrifugation through colloid after cryopreservation (SLC-AC), and 4) swim-up. Centrifugation (300 x g for 20 min) was done for all methods. The SLC-PC had a better recovery rate than the SLC-AC and swim-up methods (mean+/-SD of 16.4+/-8.7, 10.7+/-8.9, and 2.3+/-1.7%, respectively; Pblood cell contamination than simple washed samples (0.02+/-0.01, 0.02+/-0.04, 0.03+/-0.04, and 0.44+/-0.22 x 10(6) cells/mL, respectively; P0.05), SLC-PC yielded the highest percentage of sperm with normal midpieces and tails (P0.05). In conclusion, both SLC-PC and swim-up improved the quality of epididymal cat sperm, including better morphology, membrane and DNA integrity, and removal of cellular contamination. However, SLC had a better sperm recovery rate than swim-up. 2010 Elsevier Inc. All rights reserved.

  16. Spin effects in MoS{sub 2} and WS{sub 2} single layers

    Energy Technology Data Exchange (ETDEWEB)

    Kioseoglou, G. [Department of Materials Science and Technology, University of Crete, Heraklion (Greece); Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology Hellas (FORTH), Heraklion, Crete (Greece); Korkusinski, M. [Quantum Theory Group, Emerging Technologies Division, National Research Council, Ottawa, ON (Canada); Scrace, T. [University at Buffalo, SUNY, Buffalo, NY (United States); Hanbicki, A.T.; Currie, M.; Jonker, B.T.; Petrou, A. [Naval Research Laboratory, Washington, DC (United States); Hawrylak, P. [Quantum Theory Group, Emerging Technologies Division, National Research Council, Ottawa, ON (Canada); Department of Physics, University of Ottawa, ON (Canada)


    Replacing the two sublattices of carbon atoms in graphene with transition metal atoms and chalcogenide dimers results in single layers of transition metal dichalcogenides (TMDCs). TMDCs are promising new materials for light and energy harvesting, transistors, sensors and quantum information processing. One way to access the distinctive functionality of these materials is via their optical selection rules. In particular, light with positive or negative helicity is absorbed differently, therefore, understanding the interaction of circularly polarized light with various TMDCs should enable future applications. Using the examples of MoS{sub 2} and WS{sub 2} we summarize some recent results that illustrate the potential of these materials. First, when optically excited with circularly polarized light, single layers of MoS{sub 2} can emit light with an appreciable polarization. Depolarization mechanisms can be subsequently explored by monitoring the polarization of emitted photoluminescence as a function of the excess energy supplied to the system. As the energy of the pumping light increases further from the emission channel, the emission quickly becomes depolarized. The dominant relaxation mechanism is identified as phonon-assisted intervalley scattering. In single layers of WS{sub 2} containing electron gas, the main emission channel is from negatively charged excitons, or trions. In the presence of a two-dimensional electron gas this trion emission is circularly polarized at zero magnetic field, even when excited with linearly polarized light. This spontaneous circular polarization of the trion has a linear dependence on magnetic field and can be attributed to the existence of a valley polarized state of the two-dimensional electron gas. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Exploring single-layered SnSe honeycomb polymorphs for optoelectronic and photovoltaic applications (United States)

    Ul Haq, Bakhtiar; AlFaify, S.; Ahmed, R.; Butt, Faheem K.; Laref, A.; Shkir, Mohd.


    Single-layered tin selenide that shares the same structure with phosphorene and possesses intriguing optoelectronic properties has received great interest as a two-dimensional material beyond graphene and phosphorene. Herein, we explore the optoelectronic response of the newly discovered stable honeycomb derivatives (such as α , β , γ , δ , and ɛ ) of single-layered SnSe in the framework of density functional theory. The α , β , γ , and δ derivatives of a SnSe monolayer have been found to exhibit an indirect band gap, however, the dispersion of their band-gap edges demonstrates multiple direct band gaps at a relatively high energy. The ɛ -SnSe, however, features an intrinsic direct band gap at the high-symmetry Γ point. Their energy band gaps (0.53, 2.32, 1.52, 1.56, and 1.76 eV for α -, β -, γ -, δ -, and ɛ -SnSe, respectively), calculated at the level of the Tran-Blaha modified Becke-Johnson approach, mostly fall right in the visible range of the electromagnetic spectrum and are in good agreement with the available literature. The optical spectra of these two-dimensional (2D) SnSe polymorphs (besides β -SnSe) are highly anisotropic and possess strictly different optical band gaps along independent diagonal components. They show high absorption in the visible and UV ranges. Similarly, the reflectivity, refraction, and optical conductivities inherit strong anisotropy from the dielectric functions as well and are highly visible-UV polarized along the cartesian coordinates, showing them to be suitable for optical filters, polarizers, and shields against UV radiation. Our investigations suggest these single-layered SnSe allotropes as a promising 2D material for next-generation nanoscale optoelectronic and photovoltaic applications beyond graphene and phosphorene.

  18. Valley polarization in magnetically doped single-layer transition-metal dichalcogenides

    KAUST Repository

    Cheng, Yingchun


    We demonstrate that valley polarization can be induced and controlled in semiconducting single-layer transition-metal dichalcogenides by magnetic doping, which is important for spintronics, valleytronics, and photonics devices. As an example, we investigate Mn-doped MoS2 by first-principles calculations. We study how the valley polarization depends on the strength of the spin orbit coupling and the exchange interaction and discuss how it can be controlled by magnetic doping. Valley polarization by magnetic doping is also expected for other honeycomb materials with strong spin orbit coupling and the absence of inversion symmetry.

  19. Atomic-scale structure of single-layer MoS2 nanoclusters

    DEFF Research Database (Denmark)

    Helveg, S.; Lauritsen, J. V.; Lægsgaard, E.


    We have studied using scanning tunneling microscopy (STM) the atomic-scale realm of molybdenum disulfide (MoS2) nanoclusters, which are of interest as a model system in hydrodesulfurization catalysis. The STM gives the first real space images of the shape and edge structure of single-layer MoS2 n...... nanoparticles synthesized on Au(lll), and establishes a new picture of the active edge sires of the nanoclusters. The results demonstrate a way to get detailed atomic-scale information on catalysts in general....

  20. Single layer graphene electrodes for quantum dot-light emitting diodes (United States)

    Yan, Long; Zhang, Yu; Zhang, Xiaoyu; Zhao, Jia; Wang, Yu; Zhang, Tieqiang; Jiang, Yongheng; Gao, Wenzhu; Yin, Jingzhi; Zhao, Jun; Yu, William W.


    Single layer graphene was employed as the electrode in quantum dot-light emitting diodes (QD-LEDs) to replace indium tin oxide (ITO). The graphene layer demonstrated low surface roughness, good hole injection ability, and proper work function matching with the poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) layer. Together with the hole transport layer and electron transport layer, the fabricated QD-LED showed good current efficiency and power efficiency, which were even higher than an ITO-based similar device under low current density. The result indicates that graphene can be used as anodes to replace ITO in QD-LEDs.

  1. Highly simplified small molecular phosphorescent organic light emitting devices with a solution-processed single layer

    Directory of Open Access Journals (Sweden)

    Zhaokui Wang


    Full Text Available A highly simplified single layer solution-processed phosphorescent organic light emitting device (PHOLED with the maximum ηP 11.5 lm/W corresponding to EQE 9.6% has been demonstrated. The solution-processed device is shown having comparable even exceeding device performance to vacuum-processed PHOLED. The simplified device design strategy represents a pathway toward large area, low cost and high efficiency OLEDs in the future. The charge injection and conduction mechanisms in two solution- and vacuum-processed devices are also investigated by evaluating the temperature dependence of current density – voltage characteristics.

  2. Strength Comparison of Flawed Single-Layer and Multilayer AISI 301 Stainless Steel Pressure Vessels at Cryogenic Temperatures

    National Research Council Canada - National Science Library

    Pierce, William


    An experimental investigation was conducted to determine the strengths of single-layer and multilayer scale model tanks of AISI 301 stainless steel containing sharp notches and having the same total wall thickness...

  3. Effect of Substrate Permittivity and Thickness on Performance of Single-Layer, Wideband, U-Slot Antennas on Microwave Substrates

    National Research Council Canada - National Science Library

    Natarajan, V; Chatterjee, D


    This paper presents effects of substrate permittivity and thickness on the performance characteristics like impedance bandwidth, radiation efficiency and gain of a single-layer, wideband, U-slot antenna...

  4. Electronic origin of high-temperature superconductivity in single-layer FeSe superconductor. (United States)

    Liu, Defa; Zhang, Wenhao; Mou, Daixiang; He, Junfeng; Ou, Yun-Bo; Wang, Qing-Yan; Li, Zhi; Wang, Lili; Zhao, Lin; He, Shaolong; Peng, Yingying; Liu, Xu; Chen, Chaoyu; Yu, Li; Liu, Guodong; Dong, Xiaoli; Zhang, Jun; Chen, Chuangtian; Xu, Zuyan; Hu, Jiangping; Chen, Xi; Ma, Xucun; Xue, Qikun; Zhou, X J


    The recent discovery of high-temperature superconductivity in iron-based compounds has attracted much attention. How to further increase the superconducting transition temperature (T(c)) and how to understand the superconductivity mechanism are two prominent issues facing the current study of iron-based superconductors. The latest report of high-T(c) superconductivity in a single-layer FeSe is therefore both surprising and significant. Here we present investigations of the electronic structure and superconducting gap of the single-layer FeSe superconductor. Its Fermi surface is distinct from other iron-based superconductors, consisting only of electron-like pockets near the zone corner without indication of any Fermi surface around the zone centre. Nearly isotropic superconducting gap is observed in this strictly two-dimensional system. The temperature dependence of the superconducting gap gives a transition temperature T(c)~ 55 K. These results have established a clear case that such a simple electronic structure is compatible with high-T(c) superconductivity in iron-based superconductors.

  5. Single layer porous media with entrapped minerals for microscale studies of multiphase flow. (United States)

    Liefferink, R W; Naillon, A; Bonn, D; Prat, M; Shahidzadeh, N


    The behaviour of minerals (i.e. salts) such as sodium chloride and calcite in porous media is very important in various applications such as weathering of artworks, oil recovery and CO2 sequestration. We report a novel method for manufacturing single layer porous media in which minerals can be entrapped in a controlled way in order to study their dissolution and recrystallization. In addition, our manufacturing method is a versatile tool for creating monomodal, bimodal or multimodal pore size microporous media with controlled porosity ranging from 25% to 50%. These micromodels allow multiphase flows to be quantitatively studied with different microscopy techniques and can serve to validate numerical models that can subsequently be extended to the 3D situation where visualization is experimentally difficult. As an example of their use, deliquescence (dissolution by moisture absorption) of entrapped NaCl crystals is studied; our results show that the invasion of the resulting salt solution is controlled by the capillary pressure within the porous network. For hydrophilic porous media, the liquid preferentially invades the small pores whereas in a hydrophobic network the large pores are filled. Consequently, after several deliquescence/drying cycles in the hydrophilic system, the salt is transported towards the outside of the porous network via small pores; in hydrophobic micromodels, no salt migration is observed. Numerical simulations based on the characteristics of our single layer pore network agree very well with the experimental results and give more insight into the dynamics of salt transport through porous media.

  6. Strong piezoelectricity in single-layer graphene deposited on SiO2 grating substrates. (United States)

    da Cunha Rodrigues, Gonçalo; Zelenovskiy, Pavel; Romanyuk, Konstantin; Luchkin, Sergey; Kopelevich, Yakov; Kholkin, Andrei


    Electromechanical response of materials is a key property for various applications ranging from actuators to sophisticated nanoelectromechanical systems. Here electromechanical properties of the single-layer graphene transferred onto SiO2 calibration grating substrates is studied via piezoresponse force microscopy and confocal Raman spectroscopy. The correlation of mechanical strains in graphene layer with the substrate morphology is established via Raman mapping. Apparent vertical piezoresponse from the single-layer graphene supported by underlying SiO2 structure is observed by piezoresponse force microscopy. The calculated vertical piezocoefficient is about 1.4 nm V(-1), that is, much higher than that of the conventional piezoelectric materials such as lead zirconate titanate and comparable to that of relaxor single crystals. The observed piezoresponse and achieved strain in graphene are associated with the chemical interaction of graphene's carbon atoms with the oxygen from underlying SiO2. The results provide a basis for future applications of graphene layers for sensing, actuating and energy harvesting.

  7. Epitaxial Single-Layer MoS2 on GaN with Enhanced Valley Helicity

    KAUST Repository

    Wan, Yi


    Engineering the substrate of 2D transition metal dichalcogenides can couple the quasiparticle interaction between the 2D material and substrate, providing an additional route to realize conceptual quantum phenomena and novel device functionalities, such as realization of a 12-time increased valley spitting in single-layer WSe2 through the interfacial magnetic exchange field from a ferromagnetic EuS substrate, and band-to-band tunnel field-effect transistors with a subthreshold swing below 60 mV dec−1 at room temperature based on bilayer n-MoS2 and heavily doped p-germanium, etc. Here, it is demonstrated that epitaxially grown single-layer MoS2 on a lattice-matched GaN substrate, possessing a type-I band alignment, exhibits strong substrate-induced interactions. The phonons in GaN quickly dissipate the energy of photogenerated carriers through electron–phonon interaction, resulting in a short exciton lifetime in the MoS2/GaN heterostructure. This interaction enables an enhanced valley helicity at room temperature (0.33 ± 0.05) observed in both steady-state and time-resolved circularly polarized photoluminescence measurements. The findings highlight the importance of substrate engineering for modulating the intrinsic valley carriers in ultrathin 2D materials and potentially open new paths for valleytronics and valley-optoelectronic device applications.

  8. Tuning the band structure and superconductivity in single-layer FeSe by interface engineering. (United States)

    Peng, R; Xu, H C; Tan, S Y; Cao, H Y; Xia, M; Shen, X P; Huang, Z C; Wen, C H P; Song, Q; Zhang, T; Xie, B P; Gong, X G; Feng, D L


    The interface between transition metal compounds provides a rich playground for emergent phenomena. Recently, significantly enhanced superconductivity has been reported for single-layer FeSe on Nb-doped SrTiO3 substrate. Yet it remains mysterious how the interface affects the superconductivity. Here we use in situ angle-resolved photoemission spectroscopy to investigate various FeSe-based heterostructures grown by molecular beam epitaxy, and uncover that electronic correlations and superconducting gap-closing temperature (Tg) are tuned by interfacial effects. Tg up to 75 K is observed in extremely tensile-strained single-layer FeSe on Nb-doped BaTiO3, which sets a record high pairing temperature for both Fe-based superconductor and monolayer-thick films, providing a promising prospect on realizing more cost-effective superconducting device. Moreover, our results exclude the direct correlation between superconductivity and tensile strain or the energy of an interfacial phonon mode, and highlight the critical and non-trivial role of FeSe/oxide interface on the high Tg, which provides new clues for understanding its origin.

  9. Gold Dispersion and Activation on the Basal Plane of Single-Layer MoS2

    KAUST Repository

    Merida, Cindy S.


    Gold islands are typically associated with high binding affinity to adsorbates and catalytic activity. Here we present the growth of such dispersed nanoscale gold islands on single layer MoS2, prepared on an inert SiO2/Si support by chemical vapor deposition (CVD). This study offers a combination of growth process development, optical characterization, photoelectron spectroscopy at sub-micron spatial resolution, and advanced density functional theory modeling for detailed insight into the electronic interaction between gold and single-layer MoS2. In particular, we find the gold density of states in Au/MoS2/SiO2/Si to be far less well-defined than Au islands on other 2-dimensional materials such as graphene, for which we also provide data. We attribute this effect to the presence of heterogeneous Au adatom/MoS2-support interactions within the nanometer-scale gold cluster. As a consequence, theory predicts that CO will exhibit adsorption energies in excess of 1 eV at the Au cluster edges, where the local density of states is dominated by Au 5dz2 symmetry.

  10. Quality of bull spermatozoa after preparation by single-layer centrifugation. (United States)

    Goodla, Lavanya; Morrell, Jane M; Yusnizar, Yulnawati; Stålhammar, Hans; Johannisson, Anders


    The present study aimed to evaluate the effect of single-layer centrifugation (SLC) through a species-specific colloid (Androcoll-B; patent pending, J. M. Morrell) on bull sperm quality. Computer-assisted sperm analysis of motility and flow cytometric analysis of sperm viability (SYBR-14/propidium iodide staining), chromatin integrity (acridine orange staining), reactive oxygen species production [Hoechst 33258-hydroethidine-2',7'-dichlorodihydrofluorescein diacetate (HO-HE-DCFDA) staining], mitochondrial membrane potential (staining with JC-1 probe), and protein tyrosine phosphorylation (specific antibody staining) were performed on unselected and SLC-selected sperm samples. Single-layer centrifugation of bull spermatozoa resulted in the selection of a sperm population that had high mitochondrial membrane potential, a higher content of phosphorylated protein, and more reactive oxygen species than control samples. Sperm chromatin damage was lower in the SLC samples although sperm viability and motility did not differ between SLC samples and controls. These observations suggest that SLC of bull semen in a soybean-containing extender improved some, but not all, parameters of sperm quality. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  11. Single Layer Nanomaterials: The Chemical Vapor Deposition Synthesis and Atomic Scale Characterization of Hexagonal Boron Nitride and Graphene


    Gibb, Ashley L


    The design of novel nanomaterials with tunable geometries and properties has transformed chemistry and physics in recent years. In particular, recent advances in the isolation of two-dimensional films have inspired the exploration and development of stable, self-supporting single layer systems. Most notably graphene, a single layer of hexagonal sp2 carbon, has attracted interest due to intriguing electronic, optical, and mechanical properties. Hexagonal boron nitride (h-BN) is a closely relat...

  12. Magneto-transport in the zero-energy Landau level of single-layer and bilayer graphene

    International Nuclear Information System (INIS)

    Zeitler, U; Giesbers, A J M; Elferen, H J van; Kurganova, E V; McCollam, A; Maan, J C


    We present recent low-temperature magnetotransport experiments on single-layer and bilayer graphene in high magnetic field up to 33 T. In single layer graphene the fourfold degeneracy of the zero-energy Landau level is lifted by a gap opening at filling factor ν = 0. In bilayer graphene, we observe a partial lifting of the degeneracy of the eightfold degenerate zero-energy Landau level.

  13. Timing and Distribution of Single-Layered Ejecta Craters Imply Sporadic Preservation of Tropical Subsurface Ice on Mars (United States)

    Kirchoff, Michelle R.; Grimm, Robert E.


    Determining the evolution of tropical subsurface ice is a key component to understanding Mars's climate and geologic history. Study of an intriguing crater type on Mars—layered ejecta craters, which likely form by tapping subsurface ice—may provide constraints on this evolution. Layered ejecta craters have a continuous ejecta deposit with a fluidized-flow appearance. Single-layered ejecta (SLE) craters are the most common and dominate at tropical latitudes and therefore offer the best opportunity to derive new constraints on the temporal evolution of low-latitude subsurface ice. We estimate model formation ages of 54 SLE craters with diameter (D) ≥ 5 km using the density of small, superposed craters with D D 1 km indicates that ice could be preserved as shallow as 100 m or less at those locations. Finally, there is a striking spatial mixing in an area of highlands near the equator of layered and radial (lunar-like ballistic) ejecta craters; the latter form where there are insufficient concentrations of subsurface ice. This implies strong spatial heterogeneity in the concentration of tropical subsurface ice.

  14. Should nylon corneal sutures be routinely removed? (United States)

    Jackson, H.; Bosanquet, R.


    Three groups of patients who had undergone cataract extraction through a corneal incision closed with 10/0 nylon sutures one, two, and three years previously were recalled to determine the incidence of suture related complications. Broken corneal sutures were found in 87.5% of patients after two years and 90% after three years and were causing symptoms in over half the patients. It is recommended that 10/0 nylon corneal sutures be routinely removed no later than one year after surgery. Images PMID:1751460

  15. Effects of three suture techniques on complications after choledochojejunostomy

    Directory of Open Access Journals (Sweden)

    ZHOU Jinhang


    Full Text Available ObjectiveTo observe the effects of different suture techniques on complications after choledochojejunostomy. MethodsA retrospective analysis was performed on the clinical data of 162 patients who underwent choledochojejunostomy from January 2005 to December 2014 in our hospital. The patients were divided into group A undergoing simple interrupted suture (n=68, group B undergoing simple continuous suture (n=45, and group C undergoing parachute type continuous suture (n=49. The intraoperative conditions and postoperative complications were compared between the three groups. Comparison of continuous data between the three groups was made by ANOVA and pairwise comparison between any two groups was made by LSD t-tests; comparison of categorical data between the groups was made by chi-square test. ResultsThe anastomosis time and the rate of T-tube insertion showed significant differences between the three groups (P<0.05. Groups B and C had significantly shorter anastomosis time than group A(P<0.001, but there was no significant difference in the anastomosis time between groups B and C (P>0.05. Among the three groups, group A had the highest rate of T-tube insertion; group B had the second highest rate; group C had the lowest rate. Significant differences were found between any two groups in the rate of T-tube insertion by pairwise comparison (P<0.05. However, there were no significant differences between the three groups in the incidence rates of postoperative bile leakage and choleperitonitis (P>0.05. There was significant difference in biliary stricture between the three groups in the follow-up examination 6 months after surgery (P<0.001 and the differences analyzed by pairwise comparison were also significant (P<0.05. Among the three groups, the degree of biliary stricture in the group A was the highest and that in the group C was the lowest. ConclusionParachute-type continuous suture is a fine suture technique for

  16. Investigation of the best suture pattern to close a stuffed Christmas turkey. (United States)

    Verwilghen, D; Busoni, V; van Galen, G; Wilke, M

    Instructions on how to debone and stuff a turkey are available, but what is the best way to close it up? A randomised trial involving 15 turkeys was performed in order to evaluate skin disruption scores and cosmetic outcomes following the use of different suture patterns. Turkeys were deboned, stuffed and cooked according to guidelines of the US Department of Agriculture Food Safety and Inspection Services. After stuffing, they were randomly assigned to one of five closure groups: simple continuous Lembert; simple continuous Cushing; simple continuous Utrecht; simple continuous; or staples. Turkeys were cooked at 180 °C for two hours ensuring core temperature reached 75 °C. Suture line integrity was evaluated after removal of the sutures and the cosmetic aspect was graded. Before cooking, the Utrecht pattern and skin staples offered the best cosmetic result. After removal of the sutures, the skin remained intact only in the stapled group. All other suture patterns disrupted the skin after removal of the sutures, rendering the turkey less cosmetically appealing for serving. Closure of a stuffed turkey was best performed using skin staples to achieve the best cosmetic results. Using this technique you will be able to impress family and friends at a Christmas dinner, and finally show them your surgical skills.

  17. Negative quantum capacitance induced by midgap states in single-layer graphene. (United States)

    Wang, Lin; Wang, Yang; Chen, Xiaolong; Zhu, Wei; Zhu, Chao; Wu, Zefei; Han, Yu; Zhang, Mingwei; Li, Wei; He, Yuheng; Xiong, Wei; Law, Kam Tuen; Su, Dangsheng; Wang, Ning


    We demonstrate that single-layer graphene (SLG) decorated with a high density of Ag adatoms displays the unconventional phenomenon of negative quantum capacitance. The Ag adatoms act as resonant impurities and form nearly dispersionless resonant impurity bands near the charge neutrality point (CNP). Resonant impurities quench the kinetic energy and drive the electrons to the Coulomb energy dominated regime with negative compressibility. In the absence of a magnetic field, negative quantum capacitance is observed near the CNP. In the quantum Hall regime, negative quantum capacitance behavior at several Landau level positions is displayed, which is associated with the quenching of kinetic energy by the formation of Landau levels. The negative quantum capacitance effect near the CNP is further enhanced in the presence of Landau levels due to the magnetic-field-enhanced Coulomb interactions.

  18. Effect of humid-thermal environment on wave dispersion characteristics of single-layered graphene sheets (United States)

    Ebrahimi, Farzad; Dabbagh, Ali


    In the present article, the hygro-thermal wave propagation properties of single-layered graphene sheets (SLGSs) are investigated for the first time employing a nonlocal strain gradient theory. A refined higher-order two-variable plate theory is utilized to derive the kinematic relations of graphene sheets. Here, nonlocal strain gradient theory is used to achieve a more precise analysis of small-scale plates. In the framework of the Hamilton's principle, the final governing equations are developed. Moreover, these obtained equations are deemed to be solved analytically and the wave frequency values are achieved. Some parametric studies are organized to investigate the influence of different variants such as nonlocal parameter, length scale parameter, wave number, temperature gradient and moisture concentration on the wave frequency of graphene sheets.

  19. Large theoretical thermoelectric power factor of suspended single-layer MoS{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Babaei, Hasan, E-mail:, E-mail: [Mechanical Science and Engineering Department, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-2906 (United States); Mechanical Engineering Department, Auburn University, Auburn, Alabama 36849-5341 (United States); Khodadadi, J. M. [Mechanical Engineering Department, Auburn University, Auburn, Alabama 36849-5341 (United States); Sinha, Sanjiv [Mechanical Science and Engineering Department, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-2906 (United States)


    We have calculated the semi-classical thermoelectric power factor of suspended single-layer (SL)- MoS{sub 2} utilizing electron relaxation times derived from ab initio calculations. Measurements of the thermoelectric power factor of SL-MoS{sub 2} on substrates reveal poor power factors. In contrast, we find the thermoelectric power factor of suspended SL-MoS{sub 2} to peak at ∼2.8 × 10{sup 4} μW/m K{sup 2} at 300 K, at an electron concentration of 10{sup 12} cm{sup −2}. This figure is higher than that in bulk Bi{sub 2}Te{sub 3}, for example. Given its relatively high thermal conductivity, suspended SL-MoS{sub 2} may hold promise for in-plane thin-film Peltier coolers, provided reasonable mobilities can be realized.

  20. Moisture barrier properties of single-layer graphene deposited on Cu films for Cu metallization (United States)

    Gomasang, Ploybussara; Abe, Takumi; Kawahara, Kenji; Wasai, Yoko; Nabatova-Gabain, Nataliya; Thanh Cuong, Nguyen; Ago, Hiroki; Okada, Susumu; Ueno, Kazuyoshi


    The moisture barrier properties of large-grain single-layer graphene (SLG) deposited on a Cu(111)/sapphire substrate are demonstrated by comparing with the bare Cu(111) surface under an accelerated degradation test (ADT) at 85 °C and 85% relative humidity (RH) for various durations. The change in surface color and the formation of Cu oxide are investigated by optical microscopy (OM) and X-ray photoelectron spectroscopy (XPS), respectively. First-principle simulation is performed to understand the mechanisms underlying the barrier properties of SLG against O diffusion. The correlation between Cu oxide thickness and SLG quality are also analyzed by spectroscopic ellipsometry (SE) measured on a non-uniform SLG film. SLG with large grains shows high performance in preventing the Cu oxidation due to moisture during ADT.

  1. Single layered flexible photo-detector based on perylene/graphene composite through printed technology (United States)

    Ali, Shawkat; Bae, Jinho; Lee, Chong Hyun


    In this paper, a single layered passive photo sensor based on perylene/graphene composite is proposed, which is deposited in comb type silver electrodes separated as 50 μm spacing. To increase an electrical conductivity of the proposed sensor, perylene and graphene are blended. Photo sensing layer (120nm thick) and Silver electrodes (50 μm width, 350 nm thick) are deposited on poly(ethylene terephthalate) (PET) substrate through electro-hydrodynamic (EHD) system. The proposed photo sensor detects a terminal resistance inversely varied by an incident light in the range between 78 GΩ in dark and 25 GΩ at light intensity of 400lux. The device response is maximum at 465 nm ~ 535 nm wavelength range at blue light. The device exhibited bendability up to 4mm diameter for 1000 endurance cycles. The surface morphology analysis is carried out with FE-SEM and microscope.

  2. A visualization method for probing grain boundaries of single layer graphene via molecular beam epitaxy (United States)

    Zhan, Linjie; Wan, Wen; Zhu, Zhenwei; Zhao, Zhijuan; Zhang, Zhenhan; Shih, Tien-Mo; Cai, Weiwei


    Graphene, a member of layered two-dimensional (2D) materials, possesses high carrier mobility, mechanical flexibility, and optical transparency, as well as enjoying a wide range of promising applications in electronics. Adopting the chemical vaporization deposition method, the majority of investigators have ubiquitously grown single layer graphene (SLG), which inevitably involves polycrystalline properties. Here we demonstrate a simple method for the direct visualization of arbitrarily large-size SLG domains by synthesizing one-hundred-nm-scale MoS2 single crystals via a high-vacuum molecular beam epitaxy process. The present study based on epitaxial growth provides a guide for probing the grain boundaries of various 2D materials and implements higher potentials for the next-generation electronic devices.

  3. Probing Critical Point Energies of Transition Metal Dichalcogenides: Surprising Indirect Gap of Single Layer WSe 2

    KAUST Repository

    Zhang, Chendong


    By using a comprehensive form of scanning tunneling spectroscopy, we have revealed detailed quasi-particle electronic structures in transition metal dichalcogenides, including the quasi-particle gaps, critical point energy locations, and their origins in the Brillouin zones. We show that single layer WSe surprisingly has an indirect quasi-particle gap with the conduction band minimum located at the Q-point (instead of K), albeit the two states are nearly degenerate. We have further observed rich quasi-particle electronic structures of transition metal dichalcogenides as a function of atomic structures and spin-orbit couplings. Such a local probe for detailed electronic structures in conduction and valence bands will be ideal to investigate how electronic structures of transition metal dichalcogenides are influenced by variations of local environment.

  4. Polarized dependence of nonlinear susceptibility in a single layer graphene system in infrared region

    Energy Technology Data Exchange (ETDEWEB)

    Solookinejad, G., E-mail:


    In this study, the linear and nonlinear susceptibility of a single-layer graphene nanostructure driven by a weak probe light and an elliptical polarized coupling field is discussed theoretically. The Landau levels of graphene can be separated in infrared or terahertz regions under the strong magnetic field. Therefore, by using the density matrix formalism in quantum optic, the linear and nonlinear susceptibility of the medium can be derived. It is demonstrated that by adjusting the elliptical parameter, one can manipulate the linear and nonlinear absorption as well as Kerr nonlinearity of the medium. It is realized that the enhanced Kerr nonlinearity can be possible with zero linear absorption and nonlinear amplification at some values of elliptical parameter. Our results may be having potential applications in quantum information science based on Nano scales devices.

  5. Tensile loading induced phase transition and rippling in single-layer MoS2 (United States)

    Bao, Hongwei; Huang, Yuhong; Yang, Zhi; Miao, Yaping; Chu, Paul K.; Xu, Kewei; Ma, Fei


    Molecular dynamics (MD) simulation is performed to study the structural evolution of single-layer MoS2 nanosheets under tensile loading and a phase transition from hexagonal structure to quadrilateral one is observed at a large strain when loaded along the zigzag direction but not along the armchair direction. Density functional theory (DFT) calculation illustrates that the newly generated quadrilateral phase is metallic. Further loading along the zigzag direction promotes an inhomogeneous distribution of lateral and shear stress around the phase boundaries due to local mechanical mismatch. As a result, periodic rippling parallel to the loading direction emerges and the wavelength and wave height change with strain according to λ∼ε-1/4 and h∼ε1/4. Accordingly, a graded distribution of strain can be produced or modulated by a simple tensile loading and the strategy might be utilized to enhance the photoelectrical properties of 2D materials and design strain-tunable nanodevices.

  6. Effect of quenched disorder on charge-orbital-spin ordering in single-layer manganites

    International Nuclear Information System (INIS)

    Uchida, Masaya; Mathieu, Roland; He, Jinping; Kaneko, Yoshio; Tokura, Yoshinori; Asamitsu, Atsushi; Kumai, Reiji; Tomioka, Yasuhide; Matsui, Yoshio


    Structural and magnetic properties have been investigated for half-doped single-layer manganites RE 0.5 Sr 1.5 MnO 4 [RE=La, (La, Pr), Pr, Nd, Sm, and Eu]. Analyses of electron diffraction and ac susceptibility measurements have revealed that the long-range charge-orbital ordering (CO-OO) state as observed in La 0.5 Sr 1.5 MnO 4 is suppressed for the other materials: the CO-OO transition temperature, as well as the correlation length decreases with a decrease in the cation size of RE. Such a short-range CO-OO state shows a spin-glass behavior at low temperatures. A new electronic phase diagram is established with quenched disorder as the control parameter. (author)

  7. Biomimetic plasmonic color generated by the single-layer coaxial honeycomb nanostructure arrays (United States)

    Zhao, Jiancun; Gao, Bo; Li, Haoyong; Yu, Xiaochang; Yang, Xiaoming; Yu, Yiting


    We proposed a periodic coaxial honeycomb nanostructure array patterned in a silver film to realize the plasmonic structural color, which was inspired from natural honeybee hives. The spectral characteristics of the structure with variant geometrical parameters are investigated by employing a finite-difference time-domain method, and the corresponding colors are thus derived by calculating XYZ tristimulus values corresponding with the transmission spectra. The study demonstrates that the suggested structure with only a single layer has high transmission, narrow full-width at half-maximum, and wide color tunability by changing geometrical parameters. Therefore, the plasmonic colors realized possess a high color brightness, saturation, as well as a wide color gamut. In addition, the strong polarization independence makes it more attractive for practical applications. These results indicate that the recommended color-generating plasmonic structure has various potential applications in highly integrated optoelectronic devices, such as color filters and high-definition displays.

  8. Thermal vibration of rectangular single-layered black phosphorus predicted by orthotropic plate model (United States)

    Zhang, Yiqing; Wang, Lifeng; Jiang, Jingnong


    Vibrational behavior is very important for nanostructure-based resonators. In this work, an orthotropic plate model together with a molecular dynamics (MD) simulation is used to investigate the thermal vibration of rectangular single-layered black phosphorus (SLBP). Two bending stiffness, two Poisson's ratios, and one shear modulus of SLBP are calculated using the MD simulation. The natural frequency of the SLBP predicted by the orthotropic plate model agrees with the one obtained from the MD simulation very well. The root of mean squared (RMS) amplitude of the SLBP is obtained by MD simulation and the orthotropic plate model considering the law of energy equipartition. The RMS amplitude of the thermal vibration of the SLBP is predicted well by the orthotropic plate model compared to the MD results. Furthermore, the thermal vibration of the SLBP with an initial stress is also well-described by the orthotropic plate model.

  9. Large theoretical thermoelectric power factor of suspended single-layer MoS2

    International Nuclear Information System (INIS)

    Babaei, Hasan; Khodadadi, J. M.; Sinha, Sanjiv


    We have calculated the semi-classical thermoelectric power factor of suspended single-layer (SL)- MoS 2 utilizing electron relaxation times derived from ab initio calculations. Measurements of the thermoelectric power factor of SL-MoS 2 on substrates reveal poor power factors. In contrast, we find the thermoelectric power factor of suspended SL-MoS 2 to peak at ∼2.8 × 10 4 μW/m K 2 at 300 K, at an electron concentration of 10 12 cm −2 . This figure is higher than that in bulk Bi 2 Te 3 , for example. Given its relatively high thermal conductivity, suspended SL-MoS 2 may hold promise for in-plane thin-film Peltier coolers, provided reasonable mobilities can be realized

  10. The strain rate effect on the buckling of single-layer MoS2. (United States)

    Jiang, Jin-Wu


    The Euler buckling theory states that the buckling critical strain is an inverse quadratic function of the length for a thin plate in the static compression process. However, the suitability of this theory in the dynamical process is unclear, so we perform molecular dynamics simulations to examine the applicability of the Euler buckling theory for the fast compression of the single-layer MoS2. We find that the Euler buckling theory is not applicable in such dynamical process, as the buckling critical strain becomes a length-independent constant in the buckled system with many ripples. However, the Euler buckling theory can be resumed in the dynamical process after restricting the theory to an individual ripple in the buckled structure.

  11. Growth and electronic structure of single-layered transition metal dichalcogenides

    DEFF Research Database (Denmark)

    Dendzik, Maciej


    The discovery of graphene has opened a novel research direction focused on the properties of 2D materials. Transition metal dichalcogenides (TMDCs) were quickly identified as important materials due to the great variety of electronic properties that they manifest – properties that are markedly...... different from graphene’s. For example, semiconducting TMDCs undergo an indirectdirect band gap transition when thinned to a single layer (SL); this results in greatly enhanced photoluminescence, making those materials attractive for applications in optoelectronics. Furthermore, metallic TMDCs can host...... TMDCs is directly studied with angle-resolved photoemission spectroscopy (ARPES) and x-ray photoelectron spectroscopy (XPS) techniques. Experimental results are compared with density-functional theory calculations (DFT), both for a free-standing layer and for a layer adsorbed on a metallic substrate...

  12. Anomalous photoluminescence thermal quenching of sandwiched single layer MoS_2

    KAUST Repository

    Tangi, Malleswararao


    We report an unusual thermal quenching of the micro-photoluminescence (µ-PL) intensity for a sandwiched single-layer (SL) MoS2. For this study, MoS2 layers were chemical vapor deposited on molecular beam epitaxial grown In0.15Al0.85N lattice matched templates. Later, to accomplish air-stable sandwiched SL-MoS2, a thin In0.15Al0.85N cap layer was deposited on the MoS2/In0.15Al0.85N heterostructure. We confirm that the sandwiched MoS2 is a single layer from optical and structural analyses using µ-Raman spectroscopy and scanning transmission electron microscopy, respectively. By using high-resolution X-ray photoelectron spectroscopy, no structural phase transition of MoS2 is noticed. The recombination processes of bound and free excitons were analyzed by the power-dependent µ-PL studies at 77 K and room temperature (RT). The temperature-dependent micro photoluminescence (TDPL) measurements were carried out in the temperature range of 77 – 400 K. As temperature increases, a significant red-shift is observed for the free-exciton PL peak, revealing the delocalization of carriers. Further, we observe unconventional negative thermal quenching behavior, the enhancement of the µ-PL intensity with increasing temperatures up to 300K, which is explained by carrier hopping transitions that take place between shallow localized states to the band-edges. Thus, this study renders a fundamental insight into understanding the anomalous thermal quenching of µ-PL intensity of sandwiched SL-MoS2.

  13. How much do we need experts during laparoscopic suturing training? (United States)

    Van Bruwaene, Siska; De Win, Gunter; Miserez, Marc


    Because of the complex nature of laparoscopic suturing, numerous curricula have been developed to overcome the steep learning curve in a patient-free environment. Distributed training leads to better acquisition and retention of skill compared with massed training. However, this requires considerable time commitment of experts that supervise these training sessions. This study investigates the possibility of replacing expert supervision by structured training with video demonstrations and peer feedback. The study population consisted of two balanced groups of ten senior medical students with minimal experience in laparoscopy. The control group trained with continuous expert feedback while for the experimental group only video demonstrations and external feedback from peers were available. Training was completed when a previously determined expert level was achieved on two consecutive attempts (proficiency criterion). Students were tested on their suturing skills 1 week after the training as well as after 4 months. A composite score assessing quality and quantity of suturing performance was used. Data are shown as median (interquartile range, IQR). Students' performance improved more than 200% after training. Learning curves did not differ between groups (p = 0.28). One week after training, scores were 192 s (IQR 65 s) for the control and 190 s (IQR 27 s) for the experimental group (p = 0.63). After 4 months this was 223 s (IQR 88 s) and 220 s (IQR 37 s), respectively (p = 0.60). Both training methods are very efficient at improving laparoscopic suturing skills and provide excellent skill retention. We therefore conclude that structured training with video demonstrations and peer feedback can replace expert supervision to teach laparoscopic suturing skills to novices. This will facilitate practical organization of skills training.

  14. Influence of suture technique and suture material selection on the mechanics of end-to-end and end-to-side anastomoses. (United States)

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


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

  15. Rupture of uterus treated with suture. (United States)

    Klungsøyr, P; Kiserud, T


    Between August 1983 and August 1985, 63 patients in labor with uterine rupture were treated at Sidamo Regional Hospital, Yirgaalem, South Ethiopia, mainly by suture of the uterus. None of those operated on died. We recommend suturing as the treatment of choice. Hysterectomy is rarely indicated.

  16. Modified suturing contact lens for penetrating keratoplasty. (United States)

    Kramer, S G; Stewart, H L


    The authors have previously described a suturing contact lens that protects the corneal endothelium by aiding in the maintenance of the anterior chamber during penetrating keratoplasty. This report describes structural modifications of the suturing contact lens, which improve its stability and effectiveness. An additional configuration for use in corneal lacerations is presented.

  17. [An experimental assessment of methods for applying intestinal sutures in intestinal obstruction]. (United States)

    Akhmadudinov, M G


    The results of various methods used in applying intestinal sutures in obturation were studied. Three series of experiments were conducted on 30 dogs--resection of the intestine after obstruction with the formation of anastomoses by means of double-row suture (Albert--Shmiden--Lambert) in the first series (10 dogs), by a single-row suture after V. M. Mateshchuk [correction of Mateshuku] in the second series, and bu a single-row stretching suture suggested by the author in the third series. The postoperative complications and the parameters of physical airtightness of the intestinal anastomosis were studied in dynamics in the experimental animals. The results of the study: incompetence of the anastomosis sutures in the first series 6, in the second 4, and in the third series one. Adhesions occurred in all animals of the first and second series and in 2 of the third series. Six dogs of the first series died, 4 of the second, and one of the third. Study of the dynamics of the results showed a direct connection of the complications with the parameters of the physical airtightness of the anastomosis, and the last-named with the method of the intestinal suture. Relatively better results were noted in formation of the anastomosis by means of our suggested stretshing continuous suture passed through the serous, muscular, and submucous coats of the intestine.

  18. The Effect of Instrumentation on Suture Tensile Strength and Knot Pullout Strength of Common Suture Materials. (United States)

    Johnson, Peter C; Roberts, Aaron D; Hire, Justin M; Mueller, Terry L


    To determine the effect of instrumentation of suture material on knot security and tensile strength. In all, 5 types of suture material were used; 10 knots were tied without any instrumentation and 10 knots were tied with a hemostat holding tension on the first throw while the second throw was made for each suture type. Each group was tested to failure with the maximum load and mode of failure recorded. The maximum load between groups of each suture type was compared; frequency of failure through knot slippage vs material fracture was also compared between groups. There was no significant difference observed in the maximum load to failure for any suture type between instrumented and noninstrumented groups. Additionally, there was no difference between any instrumented and noninstrumented groups for material failure vs failure due to knot slippage. Instrumentation of suture material during two-hand tying does not affect the strength of suture material or knot security. Published by Elsevier Inc.

  19. Suture compression induced midpalatal suture chondrocyte apoptosis with increased caspase-3, caspase-9, Bad, Bak, Bax and Bid expression. (United States)

    Lan, Tingting; Zhao, Hanchi; Xiang, Bilu; Wang, Jun; Liu, Yang


    Previous studies found bone resorption and chondrocytes loss in mouse models of mid-palatal suture when given continuous compressive force, although chondrocytes response remained unknown. Herein, we design this study to determine how continuous compression force induces chondrocytes apoptosis. Thirty C57BL/6 male mice (aged 6 weeks) were randomly assigned into controls (not ligated to a spring), blank controls (ligated with no compression) and the compression group (ligated with 20-g compression). After 4 d, palatal tissues were sampled and stained by TB and safranin-O. Tunel staining measured the percentage of apoptotic chondrocytes, and immunohistochemistry was performed to label apoptosis-associated proteins (e.g., Bcl-2, Bcl-xl, Bax, Bak, Bid, Bad, caspase-3, caspase-8 and caspase-9). Intergroup comparison was made by the rank sum test, and P compression group was significantly decreased, while the control group remained largely unaltered. Tunel staining showed that apoptotic cell numbers in the mid-palatal suture were significantly higher than the control group. Immunohistochemistry showed that mice in the compression group had significantly increased expression of caspase-3, caspase-9, Bad, Bak, Bax and Bid; However, caspase-8 remained unaltered. No expression of Bcl-2 and Bcl-xl was detected. Continuous compression force induces chondrocytes apoptosis in the mid-palatal suture. This process might be associated with the mitochondrial pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Giant magnetoimpedance effect in sputtered single layered NiFe film and meander NiFe/Cu/NiFe film

    International Nuclear Information System (INIS)

    Chen, L.; Zhou, Y.; Lei, C.; Zhou, Z.M.; Ding, W.


    Giant magnetoimpedance (GMI) effect on NiFe thin film is very promising due to its application in developing the magnetic field sensors with highly sensitivity and low cost. In this paper, the single layered NiFe thin film and NiFe/Cu/NiFe thin film with a meander structure are prepared by the MEMS technology. The influences of sputtering parameters, film structure and conductor layer width on GMI effect in NiFe single layer and meander NiFe/Cu/NiFe film are investigated. Maximum of the GMI ratio in single layer and sandwich film is 5% and 64%, respectively. The results obtained are useful for developing the high-performance magnetic sensors based on NiFe thin film.

  1. Tuning Electronic Structure of Single Layer MoS2through Defect and Interface Engineering. (United States)

    Chen, Yan; Huang, Shengxi; Ji, Xiang; Adepalli, Kiran; Yin, Kedi; Ling, Xi; Wang, Xinwei; Xue, Jianmin; Dresselhaus, Mildred; Kong, Jing; Yildiz, Bilge


    Transition-metal dichalcogenides (TMDs) have emerged in recent years as a special group of two-dimensional materials and have attracted tremendous attention. Among these TMD materials, molybdenum disulfide (MoS 2 ) has shown promising applications in electronics, photonics, energy, and electrochemistry. In particular, the defects in MoS 2 play an essential role in altering the electronic, magnetic, optical, and catalytic properties of MoS 2 , presenting a useful way to engineer the performance of MoS 2 . The mechanisms by which lattice defects affect the MoS 2 properties are unsettled. In this work, we reveal systematically how lattice defects and substrate interface affect MoS 2 electronic structure. We fabricated single-layer MoS 2 by chemical vapor deposition and then transferred onto Au, single-layer graphene, hexagonal boron nitride, and CeO 2 as substrates and created defects in MoS 2 by ion irradiation. We assessed how these defects and substrates affect the electronic structure of MoS 2 by performing X-ray photoelectron spectroscopy, Raman and photoluminescence spectroscopies, and scanning tunneling microscopy/spectroscopy measurements. Molecular dynamics and first-principles based simulations allowed us to conclude the predominant lattice defects upon ion irradiation and associate those with the experimentally obtained electronic structure. We found that the substrates can tune the electronic energy levels in MoS 2 due to charge transfer at the interface. Furthermore, the reduction state of CeO 2 as an oxide substrate affects the interface charge transfer with MoS 2 . The irradiated MoS 2 had a faster hydrogen evolution kinetics compared to the as-prepared MoS 2 , demonstrating the concept of defect controlled reactivity in this phase. Our findings provide effective probes for energy band and defects in MoS 2 and show the importance of defect engineering in tuning the functionalities of MoS 2 and other TMDs in electronics, optoelectronics, and

  2. Monolithic-Structured Single-Layered Textile-Based Dye-Sensitized Solar Cells (United States)

    Yun, Min Ju; Cha, Seung I.; Kim, Han Seong; Seo, Seon Hee; Lee, Dong Y.


    Textile-structured solar cells are frequently discussed in the literature due to their prospective applications in wearable devices and in building integrated solar cells that utilize their flexibility, mechanical robustness, and aesthetic appearance, but the current approaches for textile-based solar cells—including the preparation of fibre-type solar cells woven into textiles—face several difficulties from high friction and tension during the weaving process. This study proposes a new structural concept and fabrication process for monolithic-structured textile-based dye-sensitized solar cells that are fabricated by a process similar to the cloth-making process, including the preparation of wires and yarns that are woven for use in textiles, printed, dyed, and packaged. The fabricated single-layered textile-based dye-sensitized solar cells successfully act as solar cells in our study, even under bending conditions. By controlling the inter-weft spacing and the number of Ti wires for the photoelectrode conductor, we have found that the performance of this type of dye-sensitized solar cell was notably affected by the spacing between photoelectrodes and counter-electrodes, the exposed areas of Ti wires to photoelectrodes, and photoelectrodes’ surface morphology. We believe that this study provides a process and concept for improved textile-based solar cells that can form the basis for further research.

  3. Field electron emission characteristics and physical mechanism of individual single-layer graphene. (United States)

    Xiao, Zhiming; She, Juncong; Deng, Shaozhi; Tang, Zikang; Li, Zhibing; Lu, Jianming; Xu, Ningsheng


    Due to its difficulty, experimental measurement of field emission from a single-layer graphene has not been reported, although field emission from a two-dimensional (2D) regime has been an attractive topic. The open surface and sharp edge of graphene are beneficial for field electron emission. A 2D geometrical effect, such as massless Dirac fermion, can lead to new mechanisms in field emission. Here, we report our findings from in situ field electron emission characterization on an individual singe-layer graphene and the understanding of the related mechanism. The measurement of field emission from the edges was done using a microanode probe equipped in a scanning electron microscope. We show that repeatable stable field emission current can be obtained after a careful conditioning process. This enables us to examine experimentally the typical features of the field emission from a 2D regime. We plot current versus applied field data, respectively, in ln(I/E(3/2)) ∼ 1/E and ln(I/E(3)) ∼ 1/E(2) coordinates, which have recently been proposed for field emission from graphene in high- and low-field regimes. It is observed that the plots all exhibit an upward bending feature, revealing that the field emission processes undergo from a low- to high-field transition. We discuss with theoretical analysis the physical mechanism responsible for the new phenomena.

  4. Pregnancy rates after artificial insemination with cooled stallion spermatozoa either with or without single layer centrifugation. (United States)

    Morrell, J M; Richter, J; Martinsson, G; Stuhtmann, G; Hoogewijs, M; Roels, K; Dalin, A-M


    A successful outcome after artificial insemination with cooled semen is dependent on many factors, the sperm quality of the ejaculate being one. Previous studies have shown that spermatozoa with good motility, normal morphology, and good chromatin integrity can be selected by means of colloid centrifugation, particularly single layer centrifugation (SLC) using species-specific colloids. The purpose of the present study was to conduct an insemination trial with spermatozoa from "normal" ejaculates, i.e., from stallions with no known fertility problem, to determine whether the improvements in sperm quality seen in SLC-selected sperm samples compared with uncentrifuged controls in laboratory tests are reflected in an increased pregnancy rate after artificial insemination. In a multicentre study, SLC-selected sperm samples and uncentrifuged controls from eight stallions were inseminated into approximately 10 mares per treatment per stallion. Ultrasound examination was carried out approximately 16 days after insemination to detect an embryonic vesicle. The pregnancy rates per cycle were 45% for controls and 69% for SLC-selected sperm samples, which is statistically significant (P < 0.0018). Thus, the improvement in sperm quality reported previously for SLC-selected sperm samples is associated with an increase in pregnancy rate, even for ejaculates from stallions with no known fertility problem. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Monolithic-Structured Single-Layered Textile-Based Dye-Sensitized Solar Cells (United States)

    Yun, Min Ju; Cha, Seung I.; Kim, Han Seong; Seo, Seon Hee; Lee, Dong Y.


    Textile-structured solar cells are frequently discussed in the literature due to their prospective applications in wearable devices and in building integrated solar cells that utilize their flexibility, mechanical robustness, and aesthetic appearance, but the current approaches for textile-based solar cells—including the preparation of fibre-type solar cells woven into textiles—face several difficulties from high friction and tension during the weaving process. This study proposes a new structural concept and fabrication process for monolithic-structured textile-based dye-sensitized solar cells that are fabricated by a process similar to the cloth-making process, including the preparation of wires and yarns that are woven for use in textiles, printed, dyed, and packaged. The fabricated single-layered textile-based dye-sensitized solar cells successfully act as solar cells in our study, even under bending conditions. By controlling the inter-weft spacing and the number of Ti wires for the photoelectrode conductor, we have found that the performance of this type of dye-sensitized solar cell was notably affected by the spacing between photoelectrodes and counter-electrodes, the exposed areas of Ti wires to photoelectrodes, and photoelectrodes’ surface morphology. We believe that this study provides a process and concept for improved textile-based solar cells that can form the basis for further research. PMID:27708359

  6. Investigating change of properties in gallium ion irradiation patterned single-layer graphene

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Quan, E-mail: [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (China); Dong, Jinyao; Bai, Bing [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Xie, Guoxin [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China)


    Besides its excellent physical properties, graphene promises to play a significant role in electronics with superior properties, which requires patterning of graphene for device integration. Here, we presented the changes in properties of single-layer graphene before and after patterning using gallium ion beam. Combined with Raman spectra of graphene, the scanning capacitance microscopy (SCM) image confirmed that a metal–insulator transition occurred after large doses of gallium ion irradiation. The changes in work function and Raman spectra of graphene indicated that the defect density increased as increasing the dose and a structural transition occurred during gallium ion irradiation. The patterning width of graphene presented an increasing trend due to the scattering influence of the impurities and the substrate. - Highlights: • The scanning capacitance microscopy image confirmed a metal–insulator transition occurred after large doses of gallium ion irradiation. • The changes indicated the defect density increased as increasing the dose and a structural transition occurred during gallium ion irradiation. • The patterning width of graphene presented a increasing trend due to the scattering influence of the impurities and the substrate.

  7. First-principles study of single-layer C-terminated BN quantum dots (United States)

    Qu, Li-Hua; Zhang, Jian-Min; Xu, Ke-Wei


    We present a first-principles study of the structural, electronic and magnetic properties of single-layer C-terminated BN quantum dots (QDs) under different hydrotreating conditions. The morphologies of QDs with fully hydrogenated edges change slightly. For the fully bared cases, the edged C-C bonds become short and protrudent edged C atoms relax inwards therefore edged zigzag C chain tends to a straight line. The cases of the partially passivated by hydrogen atom at apex, the apex C atom is not relaxed inwards and a new C-C bond is formed. The fully hydrogenated QDs especially N-rich cases are energetically more favorable than those with bared or partially hydrogenated ones. The C-terminated BN-QDs have no magnetic moment when their protrudent edged C atoms are fully passivated by hydrogen atoms, while those with bared or partially hydrogenated edges possess magnetic moments and especially for N-rich cases their magnetic moments increase with increasing QD size n for either bared or partially hydrogenated edges. The band gap of the fully hydrogenated QDs decreases oscillatorily with increasing QD size n. Moreover, for the same size n, the energy gap is wider under N-rich condition than under B-rich condition.

  8. A single-layer, planar, optofluidic Mach–Zehnder interferometer for label-free detection† (United States)

    Lapsley, Michael Ian; Chiang, I.-Kao; Zheng, Yue Bing; Ding, Xiaoyun; Mao, Xiaole


    We have developed a planar, optofluidic Mach–Zehnder interferometer for the label-free detection of liquid samples. In contrast to most on-chip interferometers which require complex fabrication, our design was realized via a simple, single-layer soft lithography fabrication process. In addition, a single-wavelength laser source and a silicon photodetector were the only optical equipment used for data collection. The device was calibrated using published data for the refractive index of calcium chloride (CaCl2) in solution, and the biosensing capabilities of the device were tested by detecting bovine serum albumin (BSA). Our design enables a refractometer with a low limit of detection (1.24 × 10−4 refractive index units (RIU)), low variability (1 × 10−4 RIU), and high sensitivity (927.88 oscillations per RIU). This performance is comparable to state-of-the-art optofluidic refractometers that involve complex fabrication processes and/or expensive, bulky optics. The advantages of our device (i.e. simple fabrication process, straightforward optical equipment, low cost, and high detection sensitivity) make it a promising candidate for future mass-producible, inexpensive, highly sensitive, label-free optical detection systems. PMID:21479332

  9. A single-layer, planar, optofluidic Mach-Zehnder interferometer for label-free detection. (United States)

    Lapsley, Michael Ian; Chiang, I-Kao; Zheng, Yue Bing; Ding, Xiaoyun; Mao, Xiaole; Huang, Tony Jun


    We have developed a planar, optofluidic Mach-Zehnder interferometer for the label-free detection of liquid samples. In contrast to most on-chip interferometers which require complex fabrication, our design was realized via a simple, single-layer soft lithography fabrication process. In addition, a single-wavelength laser source and a silicon photodetector were the only optical equipment used for data collection. The device was calibrated using published data for the refractive index of calcium chloride (CaCl(2)) in solution, and the biosensing capabilities of the device were tested by detecting bovine serum albumin (BSA). Our design enables a refractometer with a low limit of detection (1.24 × 10(-4) refractive index units (RIU)), low variability (1 × 10(-4) RIU), and high sensitivity (927.88 oscillations per RIU). This performance is comparable to state-of-the-art optofluidic refractometers that involve complex fabrication processes and/or expensive, bulky optics. The advantages of our device (i.e. simple fabrication process, straightforward optical equipment, low cost, and high detection sensitivity) make it a promising candidate for future mass-producible, inexpensive, highly sensitive, label-free optical detection systems. © The Royal Society of Chemistry 2011

  10. Broadband photodetector based on carbon nanotube thin film/single layer graphene Schottky junction (United States)

    Zhang, Teng-Fei; Li, Zhi-Peng; Wang, Jiu-Zhen; Kong, Wei-Yu; Wu, Guo-An; Zheng, Yu-Zhen; Zhao, Yuan-Wei; Yao, En-Xu; Zhuang, Nai-Xi; Luo, Lin-Bao


    In this study, we present a broadband nano-photodetector based on single-layer graphene (SLG)-carbon nanotube thin film (CNTF) Schottky junction. It was found that the as-fabricated device exhibited obvious sensitivity to a wide range of illumination, with peak sensitivity at 600 and 920 nm. In addition, the SLG-CNTF device had a fast response speed (τr = 68 μs, τf = 78 μs) and good reproducibility in a wide range of switching frequencies (50-5400 Hz). The on-off ratio, responsivity, and detectivity of the device were estimated to be 1 × 102, 209 mAW-1 and 4.87 × 1010 cm Hz1/2 W-1, respectively. What is more, other device parameters including linear performance θ and linear dynamic range (LDR) were calculated to be 0.99 and 58.8 dB, respectively, which were relatively better than other carbon nanotube based devices. The totality of the above study signifies that the present SLG-CNTF Schottky junction broadband nano-photodetector may have promising application in future nano-optoelectronic devices and systems.

  11. Adhesion and migration of CHO cells on micropatterned single layer graphene (United States)

    Keshavan, S.; Oropesa-Nuñez, R.; Diaspro, A.; Canale, C.; Dante, S.


    Cell patterning technology on single layer graphene (SLG) is a fairly new field that can find applications in tissue engineering and biomaterial/biosensors development. Recently, we have developed a simple and effective approach for the fabrication of patterned SLG substrates by laser micromachining, and we have successfully applied it for the obtainment of geometrically ordered neural networks. Here, we exploit the same approach to investigate the generalization of the cell response to the surface cues of the fabricated substrates and, contextually, to quantify cell adhesion on the different areas of the patterns. To attain this goal, we tested Chinese hamster ovary (CHO) cells on PDL-coated micropatterned SLG substrates and quantified the adhesion by using single cell force spectroscopy (SCFS). Our results indicate higher cell adhesion on PDL-SLG, and, consequently, an initial CHO cell accumulation on the graphene areas, confirming the neuronal behaviour observed previously; interestingly, at later time point in culture, cell migration was observed towards the adjacent SLG ablated regions, which resulted more favourable for cell proliferation. Therefore, our findings indicate that the mechanism of interaction with the surface cues offered by the micropatterned substrates is strictly cell-type dependent.

  12. Compact Single-Layer Traveling-Wave Antenna DesignUsing Metamaterial Transmission Lines (United States)

    Alibakhshikenari, Mohammad; Virdee, Bal Singh; Limiti, Ernesto


    This paper presents a single-layer traveling-wave antenna (TWA) that is based on composite right/left-handed (CRLH)-metamaterial (MTM) transmission line (TL) structure, which is implemented by using a combination of interdigital capacitors and dual-spiral inductive slots. By embedding dual-spiral inductive slots inside the CRLH MTM-TL results in a compact TWA. Dimensions of the proposed CRLH MTM-TL TWA is 21.5 × 30.0 mm2 or 0.372λ0 × 0.520λ0 at 5.2 GHz (center frequency). The fabricated TWA operates over 1.8-8.6 GHz with a fractional bandwidth greater than 120%, and it exhibits a peak gain and radiation efficiency of 4.2 dBi and 81%, respectively, at 5 GHz. By avoiding the use of lumped components, via-holes or defected ground structures, the proposed TWA design is economic for mass production as well as easy to integrate with wireless communication systems.

  13. Substitutional impurity in single-layer graphene: The Koster–Slater and Anderson models

    Energy Technology Data Exchange (ETDEWEB)

    Davydov, S. Yu., E-mail: [Russian Academy of Sciences, Ioffe Physical–Technical Institute (Russian Federation)


    The Koster–Slater and Anderson models are used to consider substitutional impurities in free-standing single-layer graphene. The density of states of graphene is described using a model (the M model). For the nitrogen and boron impurities, the occupation numbers and the parameter η which defines the fraction of delocalized electrons of the impurity are determined. In this case, experimental data are used for both determination of the model parameters and comparison with the results of theoretical estimations. The general features of the Koster–Slater and Anderson models and the differences between the two models are discussed. Specifically, it is shown that the band contributions to the occupation numbers of a nitrogen atom in both models are comparable, whereas the local contributions are substantially different: the local contributions are decisive in the Koster–Slater model and negligible in the Anderson model. The asymptotic behavior of the wave functions of a defect is considered in the Koster–Slater model, and the electron states of impurity dimers are considered in the Anderson model.

  14. Determination of band offsets at GaN/single-layer MoS2 heterojunction

    KAUST Repository

    Tangi, Malleswararao


    We report the band alignment parameters of the GaN/single-layer (SL) MoS2 heterostructure where the GaN thin layer is grown by molecular beam epitaxy on CVD deposited SL-MoS2/c-sapphire. We confirm that the MoS2 is an SL by measuring the separation and position of room temperature micro-Raman E1 2g and A1 g modes, absorbance, and micro-photoluminescence bandgap studies. This is in good agreement with HRTEM cross-sectional analysis. The determination of band offset parameters at the GaN/SL-MoS2 heterojunction is carried out by high-resolution X-ray photoelectron spectroscopy accompanying with electronic bandgap values of SL-MoS2 and GaN. The valence band and conduction band offset values are, respectively, measured to be 1.86 ± 0.08 and 0.56 ± 0.1 eV with type II band alignment. The determination of these unprecedented band offset parameters opens up a way to integrate 3D group III nitride materials with 2D transition metal dichalcogenide layers for designing and modeling of their heterojunction based electronic and photonic devices.

  15. Single Layer Bismuth Iodide: Computational Exploration of Structural, Electrical, Mechanical and Optical Properties (United States)

    Ma, Fengxian; Zhou, Mei; Jiao, Yalong; Gao, Guoping; Gu, Yuantong; Bilic, Ante; Chen, Zhongfang; Du, Aijun


    Layered graphitic materials exhibit new intriguing electronic structure and the search for new types of two-dimensional (2D) monolayer is of importance for the fabrication of next generation miniature electronic and optoelectronic devices. By means of density functional theory (DFT) computations, we investigated in detail the structural, electronic, mechanical and optical properties of the single-layer bismuth iodide (BiI3) nanosheet. Monolayer BiI3 is dynamically stable as confirmed by the computed phonon spectrum. The cleavage energy (Ecl) and interlayer coupling strength of bulk BiI3 are comparable to the experimental values of graphite, which indicates that the exfoliation of BiI3 is highly feasible. The obtained stress-strain curve shows that the BiI3 nanosheet is a brittle material with a breaking strain of 13%. The BiI3 monolayer has an indirect band gap of 1.57 eV with spin orbit coupling (SOC), indicating its potential application for solar cells. Furthermore, the band gap of BiI3 monolayer can be modulated by biaxial strain. Most interestingly, interfacing electrically active graphene with monolayer BiI3 nanosheet leads to enhanced light absorption compared to that in pure monolayer BiI3 nanosheet, highlighting its great potential applications in photonics and photovoltaic solar cells.

  16. Investigating change of properties in gallium ion irradiation patterned single-layer graphene

    International Nuclear Information System (INIS)

    Wang, Quan; Dong, Jinyao; Bai, Bing; Xie, Guoxin


    Besides its excellent physical properties, graphene promises to play a significant role in electronics with superior properties, which requires patterning of graphene for device integration. Here, we presented the changes in properties of single-layer graphene before and after patterning using gallium ion beam. Combined with Raman spectra of graphene, the scanning capacitance microscopy (SCM) image confirmed that a metal–insulator transition occurred after large doses of gallium ion irradiation. The changes in work function and Raman spectra of graphene indicated that the defect density increased as increasing the dose and a structural transition occurred during gallium ion irradiation. The patterning width of graphene presented an increasing trend due to the scattering influence of the impurities and the substrate. - Highlights: • The scanning capacitance microscopy image confirmed a metal–insulator transition occurred after large doses of gallium ion irradiation. • The changes indicated the defect density increased as increasing the dose and a structural transition occurred during gallium ion irradiation. • The patterning width of graphene presented a increasing trend due to the scattering influence of the impurities and the substrate.

  17. Two-band induced superconductivity in single-layer graphene and topological insulator bismuth selenide (United States)

    Talantsev, E. F.; Crump, W. P.; Tallon, J. L.


    Proximity-induced superconductivity in single-layer graphene (SLG) and in topological insulators represent almost ideal examples of superconductivity in two dimensions. Fundamental mechanisms governing superconductivity in the 2D limit are of central interest for modern condensed-matter physics. To deduce fundamental parameters of superconductor/graphene/superconductor and superconductor/bismuth selenide/superconductor junctions we investigate the self-field critical currents in these devices using the formalism of the Ambegaokar–Baratoff model. Our central finding is that the induced superconducting state in SLG and bismuth selenide each exhibits gapping on two superconducting bands. Based on recent results obtained on ultra-thin films of natural superconductors, including single-atomic layer of iron selenide, double and triple atomic layers of gallium, and several atomic layer tantalum disulphide, we conclude that a two-band induced superconducting state in SLG and bismuth selenide is part of a wider, more general multiple-band phenomenology of currently unknown origin.

  18. Band Alignment at GaN/Single-Layer WSe2 Interface

    KAUST Repository

    Tangi, Malleswararao


    We study the band discontinuity at the GaN/single-layer (SL) WSe2 heterointerface. The GaN thin layer is epitaxially grown by molecular beam epitaxy on chemically vapor deposited SL-WSe2/c-sapphire. We confirm that the WSe2 was formed as an SL from structural and optical analyses using atomic force microscopy, scanning transmission electron microscopy, micro-Raman, absorbance, and microphotoluminescence spectra. The determination of band offset parameters at the GaN/SL-WSe2 heterojunction is obtained by high-resolution X-ray photoelectron spectroscopy, electron affinities, and the electronic bandgap values of SL-WSe2 and GaN. The valence band and conduction band offset values are determined to be 2.25 ± 0.15 and 0.80 ± 0.15 eV, respectively, with type II band alignment. The band alignment parameters determined here provide a route toward the integration of group III nitride semiconducting materials with transition metal dichalcogenides (TMDs) for designing and modeling of their heterojunction-based electronic and optoelectronic devices.

  19. A single-layer tilting actuator with multiple close-gap electrodes

    International Nuclear Information System (INIS)

    Shmilovich, T; Krylov, S


    We report on the design, fabrication and characterization of a novel tilting electrostatic actuator, fabricated by using a single layer of a silicon on insulator (SOI) wafer and investigate, both theoretically and experimentally, the electromechanical behavior of the device. The actuator incorporates high aspect ratio comb-like electrodes oriented in the direction parallel to the rotation axis of the tilting element. An increase in the tilting angle is accompanied by a decrease in the distance between the electrodes and by an increase of the actuating torque. Simultaneously, the overlap area between electrodes located farther apart the axis shrinks, resulting in a 'restoring' torque in the opposite direction. The electromechanical behavior and stability of the device were investigated using a simplified model of the actuator and verified by a coupled three-dimensional simulation. Model results suggest that by changing the design parameters, the actuator characteristic can be tailored in a large range. Devices of three different configurations incorporating elastic torsion axes or bending flexures were fabricated and characterized and both static and resonant responses, typical for parametrically excited nonlinear oscillators, were registered. Theoretical and experimental results indicate that the suggested architecture can be efficiently used for the static and dynamic operation of electrostatic tilting devices

  20. Single-layer tungsten oxide as intelligent photo-responsive nanoagents for permanent male sterilization. (United States)

    Liu, Zhen; Liu, Xianjun; Ran, Xiang; Ju, Enguo; Ren, Jinsong; Qu, Xiaogang


    Permanent male sterilization has been recognized as useful tools for the development of neuter experimental animals and fattening livestock, as well as efficient control of pet overpopulation. Traditional routes such as surgical ways, chemical injections, and anti-fertility vaccines have addressed these crucial problems with idea outcomes. However, these routes usually bring out serious pain and infection towards animals, as well as induce long-term adverse reaction and immune suppression. Thus, a convenient, but non-surgical strategy for male sterilization under a mild manner is highly desirable. Here, for the first time, we demonstrate a novel platform for male sterilization by using single-layer WO2.72 nanosheets as smart photo-responsive sterilants. Upon a 980 nm irradiation, these nanoagents can possess intrinsic NIR-induced hyperthermia and sensitize the formation of singlet oxygen due to the cooperation of photothermal and photodynamic effects. Mechanism of cellular injury can be attributed to the denaturation of protein and apoptosis-related death. Moreover, long-term toxicity and possible metabolism route after testicular injection are discussed, indicating the neglectable systemic toxicity and high bio-compatibility of our nanoagents. Overall, our strategy can extremely overcome the shortcomings in various routine routes and suggest the new biological application of nanomaterials. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Unexpected strong magnetism of Cu doped single-layer MoS₂ and its origin. (United States)

    Yun, Won Seok; Lee, J D


    The magnetism of the 3d transition-metal (TM) doped single-layer (1L) MoS2, where the Mo atom is partially replaced by the 3d TM atom, is investigated using the first-principles density functional calculations. In a series of 3d TM doped 1L-MoS2's, the induced spin polarizations are negligible for Sc, Ti, and Cr dopings, while the induced spin polarizations are confirmed for V, Mn, Fe, Co, Ni, Cu, and Zn dopings and the systems become magnetic. Especially, the Cu doped system shows unexpectedly strong magnetism although Cu is nonmagnetic in its bulk state. The driving force is found to be a strong hybridization between Cu 3d states and 3p states of neighboring S, which results in an extreme unbalanced spin-population in the spin-split impurity bands near the Fermi level. Finally, we also discuss further issues of the Cu induced magnetism of 1L-MoS2 such as investigation of additional charge states, the Cu doping at the S site instead of the Mo site, and the Cu adatom on the layer (i.e., 1L-MoS2).

  2. Engineering of electronic properties of single layer graphene by swift heavy ion irradiation (United States)

    Kumar, Sunil; Kumar, Ashish; Tripathi, Ambuj; Tyagi, Chetna; Avasthi, D. K.


    In this work, swift heavy ion irradiation induced effects on the electrical properties of single layer graphene are reported. The modulation in minimum conductivity point in graphene with in-situ electrical measurement during ion irradiation was studied. It is found that the resistance of graphene layer decreases at lower fluences up to 3 × 1011 ions/cm2, which is accompanied by the five-fold increase in electron and hole mobilities. The ion irradiation induced increase in electron and hole mobilities at lower fluence up to 1 × 1011 ions/cm2 is verified by separate Hall measurements on another irradiated graphene sample at the selected fluence. In contrast to the adverse effects of irradiation on the electrical properties of materials, we have found improvement in electrical mobility after irradiation. The increment in mobility is explained by considering the defect annealing in graphene after irradiation at a lower fluence regime. The modification in carrier density after irradiation is also observed. Based on findings of the present work, we suggest ion beam irradiation as a useful tool for tuning of the electrical properties of graphene.

  3. Abrupt change of luminescence spectrum in single-layer phosphorescent polymer light emitting diode

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, X.; Lee, D.-H.; Chae, H. [School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Cho, S.M., E-mail: [School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Advanced Materials and Process Research Center for IT, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)


    PVK-based single-layer phosphorescent polymer OLEDs (organic light emitting diodes) with different rubrene concentrations were fabricated and examined for the Foerster energy transfer from phosphorescent FIrpic dye to rubrene. We found out that at a certain rubrene concentration the energy transfer occurs abruptly and the transfer shows an abnormal evolution of electroluminescence (EL) spectrum due to the coincidence of peak wavelengths of bis[(4,6-difluorophenyl)-pyridinato-N,C{sup 2'}](picolinate) iridium(III) (FIrpic) emission and 5,6,11,12-tetraphenylnaphthacene (rubrene) absorption. With the calculation of Foerster radius and average distance between FIrpic molecules, we have related the calculated ratio between the number of FIrpic molecules within to that out of Foerster radius with the degree of Foerster energy transfer from EL spectra measured in the experiment. Experimental results were found to fit well with the predicted results especially at low rubrene concentrations. - Highlights: > Foerster energy transfer between FIrpic and rubrene. > Energy transfer shows an abnormal evolution of emission spectrum. > Calculated Foerster radius and degree of energy transfer by a simple model.

  4. A single-layer peptide nanofiber for enhancing the cytotoxicity of trastuzumab (anti-HER)

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Ruchi; Wagh, Anil; Qian, Steven; Law, Benedict, E-mail: [College of Pharmacy, Nursing, and Allied Sciences, North Dakota State University, Department of Pharmaceutical Sciences (United States)


    A multivalent system is often employed to enhance the effectiveness of a targeted therapy. In the present study, we report a single-layer peptide nanofiber (NFP) as a multivalent targeting platform to improve the cytotoxicity of trastuzumab (anti-HER), a monoclonal antibody targeting the human epidermal growth factor receptor 2 (HER-2) in approximately 20 % of breast cancer patients. The trastuzumab-conjugated nanofiber (anti-HER/NFP) was 100 Multiplication-Sign 4 nm in size and was assembled from multiple peptide units (mPEG-BK(FITC)SGASNRA-kldlkldlkldl-CONH{sub 2}). The optimized preparation was attached with approximately 10 antibodies at the surface. Because of an increase in the multivalency, anti-HER/NFP was able to truncate more cell surface HER-2 and, thus, showed an enhanced cytotoxicity toward HER-2 positive SKBr-3 human breast cancer as compared to the free anti-HER. Western blot analysis and fluorescence microscopic studies confirmed that there was a significant downregulation of the HER-2 level and also inhibition of the cell survival cell signaling pathways including the phosphatidylinositol 3-kinase (PI3K) and the mitogen activated protein kinase (MAPK) pathway. Our data suggested that NFP can be useful as a multivalent platform for immunotherapy, especially in combination with other chemotherapeutic agents in the future.

  5. The Stability of New Single-Layer Combined Lattice Shell Based on Aluminum Alloy Honeycomb Panels

    Directory of Open Access Journals (Sweden)

    Caiqi Zhao


    Full Text Available This article proposes a new type of single-layer combined lattice shell (NSCLS; which is based on aluminum alloy honeycomb panels. Six models with initial geometric defect were designed and precision made using numerical control equipment. The stability of these models was tested. The results showed that the stable bearing capacity of NSCLS was approximately 16% higher than that of a lattice shell with the same span without a reinforcing plate. At the same time; the properties of the NSCLS were sensitive to defects. When defects were present; its stable bearing capacity was decreased by 12.3% when compared with the defect-free model. The model with random defects following a truncated Gaussian distribution could be used to simulate the distribution of defects in the NSCLS. The average difference between the results of the nonlinear analysis and the experimental results was 5.7%. By calculating and analyzing nearly 20,000 NSCLS; the suggested values of initial geometric defect were presented. The results of this paper could provide a theoretical basis for making and revising the design codes for this new combined lattice shell structure.

  6. Effect of cushioned or single layer semen centrifugation before sex sorting on frozen stallion semen quality. (United States)

    Mari, G; Bucci, D; Love, C C; Mislei, B; Rizzato, G; Giaretta, E; Merlo, B; Spinaci, M


    The aim of this study was to compare the effect of presorting centrifugation (cushioned [CC] or single-layer colloid [SLC]), with simple dilution (SD), on the quality of sex-sorted stallion semen before and after sorting and after freezing and thawing. Four ejaculates from each of two fertile stallions were collected 1 week apart and evaluated for percent total sperm motility (TM), percent viable acrosome-intact sperm (VAI), and DNA quality (percentage of DNA fragmentation index). Freezing caused, independently from CC and SLC treatments, a significant decrease of TM (P < 0.05) and VAI (P < 0.05) in both unsorted and sorted semen. On the other hand, sorting did not impair TM and VAI and, interestingly, improved DNA quality in all treatments only before freezing (28 vs 13, 28 vs 10, 22 vs 7 in SD, CC, and SLC for unsorted vs sorted groups, respectively; P < 0.05); this positive effect was lost in the same samples after freezing and thawing, suggesting that the freezing process reduces the DNA quality of sex-sorted sperm. Our results suggest that CC and SLC are not able to select those spermatozoa that possess a better ability to withstand sperm processing associated with sperm sorting and freezing. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Single layer centrifugation-selected boar spermatozoa are capable of fertilization in vitro (United States)


    Background Good quality spermatozoa are important to achieve fertilization, viable embryos and offspring. Single Layer Centrifugation (SLC) through a colloid (Androcoll-P) selects good quality spermatozoa. However, it has not been established previously whether porcine spermatozoa selected by this method maintain their fertility. Methods The semen was prepared either by SLC or by standard centrifugation (control) and used for in vitro fertilization (IVF) at oocyte:spermatozoa ratios of 1:50; 1:100 and 1:300 (or 4 x 103, 8 x 103 and 24 x 103 spermatozoa/ml) to evaluate their subsequent ability to generate blastocysts. In addition, sperm motility was assessed by computer assisted sperm motility analysis. Results Total and progressive motility were significantly higher in sperm samples prepared by SLC compared to uncentrifuged samples. Sperm binding ability, polyspermy, cleavage and blastocyst rates were affected by the oocyte:sperm ratio, but not by sperm treatment. Conclusion The use of SLC does not adversely affect the in vitro fertilizing and embryo-generating ability of the selected spermatozoa compared to their unselected counterparts, but further modifications in the IVF conditions would be needed to improve the monospermy in IVF systems. Since SLC did not appear to have a negative effect on sperm fertilizing ability, and may in fact select for spermatozoa with a greater potential for fertilization, an in vivo trial to determine the usefulness of this sperm preparation technique prior to artificial insemination is warranted. PMID:23497680

  8. Local Electronic Structure of a Single-Layer Porphyrin-Containing Covalent Organic Framework

    KAUST Repository

    Chen, Chen


    We have characterized the local electronic structure of a porphyrin-containing single-layer covalent organic framework (COF) exhibiting a square lattice. The COF monolayer was obtained by the deposition of 2,5-dimethoxybenzene-1,4-dicarboxaldehyde (DMA) and 5,10,15,20-tetrakis(4-aminophenyl) porphyrin (TAPP) onto a Au(111) surface in ultrahigh vacuum followed by annealing to facilitate Schiff-base condensations between monomers. Scanning tunneling spectroscopy (STS) experiments conducted on isolated TAPP precursor molecules and the covalently linked COF networks yield similar transport (HOMO-LUMO) gaps of 1.85 ± 0.05 eV and 1.98 ± 0.04 eV, respectively. The COF orbital energy alignment, however, undergoes a significant downward shift compared to isolated TAPP molecules due to the electron-withdrawing nature of the imine bond formed during COF synthesis. Direct imaging of the COF local density of states (LDOS) via dI/dV mapping reveals that the COF HOMO and LUMO states are localized mainly on the porphyrin cores and that the HOMO displays reduced symmetry. DFT calculations reproduce the imine-induced negative shift in orbital energies and reveal that the origin of the reduced COF wave function symmetry is a saddle-like structure adopted by the porphyrin macrocycle due to its interactions with the Au(111) substrate.

  9. A multicenter randomized controlled trial comparing absorbable barbed sutures versus conventional absorbable sutures for dermal closure in open surgical procedures. (United States)

    Rubin, J Peter; Hunstad, Joseph P; Polynice, Alain; Gusenoff, Jeffrey A; Schoeller, Thomas; Dunn, Raymond; Walgenbach, Klaus J; Hansen, Juliana E


    Barbed sutures were developed to reduce operative time and improve security of wound closure. The authors compare absorbable barbed sutures (V-Loc, Covidien, Mansfield, Massachusetts) with conventional (smooth) absorbable sutures for soft tissue approximation. A prospective multicenter randomized study comparing barbed sutures with smooth sutures was undertaken between August 13, 2009, and January 31, 2010, in 241 patients undergoing abdominoplasty, mastopexy, and reduction mammaplasty. Each patient received barbed sutures on 1 side of the body, with deep dermal sutures eliminated or reduced. Smooth sutures with deep dermal and subcuticular closure were used on the other side as a control. The primary endpoint was dermal closure time. Safety was assessed through adverse event reporting through a 12-week follow-up. A total of 229 patients were ultimately treated (115 with slow-absorbing polymer and 114 with rapid-absorbing polymer). Mean dermal closure time was significantly quicker with the barbed suture compared with the smooth suture (12.0 vs 19.2 minutes; P<.001), primarily due to the need for fewer deep dermal sutures. The rapid-absorbing barbed suture showed a complication profile equivalent to the smooth suture, while the slow-absorbing barbed suture had a higher incidence of minor suture extrusion. Barbed sutures enabled faster dermal closure quicker than smooth sutures, with a comparable complication profile. 1.

  10. Suture slippage in knotless suture anchors resulting in subacromial-subdeltoid bursitis. (United States)

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


    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. Plasma process-induced latent damage on gate oxide - demonstrated by single-layer and multi-layer antenna structures

    NARCIS (Netherlands)

    Wang, Zhichun; Ackaert, Jan; Salm, Cora; Kuper, F.G.


    In this paper, by using both single-layer (SL) and multi-layer (ML) or stacked antenna structures, a simple experimental method is proposed to directly demonstrate the pure plasma process-induced latent damage on gate oxide without any impact of additional defects generated by normal constant

  12. Novel High Efficient Coatings for Anti-Microbial Surgical Sutures Using Chlorhexidine in Fatty Acid Slow-Release Carrier Systems (United States)

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


    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

  13. Novel high efficient coatings for anti-microbial surgical sutures using chlorhexidine in fatty acid slow-release carrier systems. (United States)

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


    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.

  14. Identification of IGF-I in the calvarial suture of young rats: histochemical analysis of the cranial sagittal sutures in a hyperthyroid rat model. (United States)

    Akita, S; Hirano, A; Fujii, T


    Premature closure of cranial sutures has been known as one of the complications of juvenile or congenital hyperthyroidism. Thyroid hormone is an anabolic agent for bone formation in the early stages of childhood development. In children, excess thyroid hormone acts as an acceleration factor for the skeletal bone, whereas in adult hyperthyroidism, it causes bone mineral loss due to the high turnover rate of bone formation and consequently bone resorption. In addition, there are numerous literature descriptions concerning the interactions among bone metabolism, hormones, and growth factors, among which insulin-like growth factor I (IGF-I) is the most abundantly found growth factor in osteoblasts and in bone models in vivo. We therefore investigated whether or not the cranial sutures show accelerated closure and how the local growth factors or cytokines participate and function in local bone metabolism after administration of exogenous excess thyroid hormone in a rat model. A total of 60 female Wistar rats, aged 10 days, were divided into two groups, the triiodothyronine (T3)-treated group (n = 30, T3 0.1 microgram/gm of body weight per day) and the control group (n = 30, saline vehicle only), and were maintained and subsequently sacrificed at 15, 30, and 60 days. The parameters of cranial width derived from the morphologic measurements of the skull indicated that the lambda-asterion distance at 30 days and the pterion-bregma distance at 60 days in the T3-treated group were significantly decreased compared with those of the control group. Furthermore, the fluorescent histologic findings showed fluorescent labeling with no interruption along the suture edges, suggesting continuous bone formation, and displayed narrowing of the suture gap of the sagittal suture in the T3-treated group. Tartrate resistant acid phosphatase staining showed very little osteoclastic activity in the sagittal suture, especially in the T3-treated group. The intensity of immunohistochemical

  15. Seamless lamination of a concave-convex architecture with single-layer graphene (United States)

    Park, Ji-Hoon; Lim, Taekyung; Baik, Jaeyoon; Seo, Keumyoung; Moon, Youngkwon; Park, Noejung; Shin, Hyun-Joon; Kyu Kwak, Sang; Ju, Sanghyun; Real Ahn, Joung


    Graphene has been used as an electrode and channel material in electronic devices because of its superior physical properties. Recently, electronic devices have changed from a planar to a complicated three-dimensional (3D) geometry to overcome the limitations of planar devices. The evolution of electronic devices requires that graphene be adaptable to a 3D substrate. Here, we demonstrate that chemical-vapor-deposited single-layer graphene can be transferred onto a silicon dioxide substrate with a 3D geometry, such as a concave-convex architecture. A variety of silicon dioxide concave-convex architectures were uniformly and seamlessly laminated with graphene using a thermal treatment. The planar graphene was stretched to cover the concave-convex architecture, and the resulting strain on the curved graphene was spatially resolved by confocal Raman spectroscopy; molecular dynamic simulations were also conducted and supported the observations. Changes in electrical resistivity caused by the spatially varying strain induced as the graphene-silicon dioxide laminate varies dimensionally from 2D to 3D were measured by using a four-point probe. The resistivity measurements suggest that the electrical resistivity can be systematically controlled by the 3D geometry of the graphene-silicon dioxide laminate. This 3D graphene-insulator laminate will broaden the range of graphene applications beyond planar structures to 3D materials.Graphene has been used as an electrode and channel material in electronic devices because of its superior physical properties. Recently, electronic devices have changed from a planar to a complicated three-dimensional (3D) geometry to overcome the limitations of planar devices. The evolution of electronic devices requires that graphene be adaptable to a 3D substrate. Here, we demonstrate that chemical-vapor-deposited single-layer graphene can be transferred onto a silicon dioxide substrate with a 3D geometry, such as a concave-convex architecture. A

  16. Determination of the optimized single-layer ionospheric height for electron content measurements over China (United States)

    Li, Min; Yuan, Yunbin; Zhang, Baocheng; Wang, Ningbo; Li, Zishen; Liu, Xifeng; Zhang, Xiao


    The ionosphere effective height (IEH) is a very important parameter in total electron content (TEC) measurements under the widely used single-layer model assumption. To overcome the requirement of a large amount of simultaneous vertical and slant ionospheric observations or dense "coinciding" pierce points data, a new approach comparing the converted vertical TEC (VTEC) value using mapping function based on a given IEH with the "ground truth" VTEC value provided by the combined International GNSS Service Global Ionospheric Maps is proposed for the determination of the optimal IEH. The optimal IEH in the Chinese region is determined using three different methods based on GNSS data. Based on the ionosonde data from three different locations in China, the altitude variation of the peak electron density (hmF2) is found to have clear diurnal, seasonal and latitudinal dependences, and the diurnal variation of hmF2 varies from approximately 210 to 520 km in Hainan. The determination of the optimal IEH employing the inverse method suggested by Birch et al. (Radio Sci 37, 2002. doi: 10.1029/2000rs002601) did not yield a consistent altitude in the Chinese region. Tests of the method minimizing the mapping function errors suggested by Nava et al. (Adv Space Res 39:1292-1297, 2007) indicate that the optimal IEH ranges from 400 to 600 km, and the height of 450 km is the most frequent IEH at both high and low solar activities. It is also confirmed that the IEH of 450-550 km is preferred for the Chinese region instead of the commonly adopted 350-450 km using the determination method of the optimal IEH proposed in this paper.

  17. Electronic and optical properties of vacancy defects in single-layer transition metal dichalcogenides (United States)

    Khan, M. A.; Erementchouk, Mikhail; Hendrickson, Joshua; Leuenberger, Michael N.


    A detailed first-principles study has been performed to evaluate the electronic and optical properties of single-layer (SL) transition metal dichalcogenides (TMDCs) (M X 2 ; M = transition metal such as Mo, W, and X = S, Se, Te), in the presence of vacancy defects (VDs). Defects usually play an important role in tailoring electronic, optical, and magnetic properties of semiconductors. We consider three types of VDs in SL TMDCs: (i) X vacancy, (ii) X2 vacancy, and (iii) M vacancy. We show that VDs lead to localized defect states (LDS) in the band structure, which in turn gives rise to sharp transitions in in-plane and out-of-plane optical susceptibilities, χ∥ and χ⊥. The effects of spin-orbit coupling (SOC) are also considered. We find that SOC splitting in LDS is directly related to the atomic number of the transition metal atoms. Apart from electronic and optical properties we also find magnetic signatures (local magnetic moment of ˜μB ) in MoSe2 in the presence of the Mo vacancy, which breaks the time-reversal symmetry and therefore lifts the Kramers degeneracy. We show that a simple qualitative tight-binding model (TBM), involving only the hopping between atoms surrounding the vacancy with an on-site SOC term, is sufficient to capture the essential features of LDS. In addition, the existence of the LDS can be understood from the solution of the two-dimensional Dirac Hamiltonian by employing infinite mass boundary conditions. In order to provide a clear description of the optical absorption spectra, we use group theory to derive the optical selection rules between LDS for both χ∥ and χ⊥.

  18. The hidden X suture: a technical note on a novel suture technique for alveolar ridge preservation. (United States)

    Park, Jung-Chul; Koo, Ki-Tae; Lim, Hyun-Chang


    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. 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. 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 preserving horizontal width and minimizing vertical reduction in comparison to X suture ( P preserving the width of KT and the dimensions of the alveolar ridge after ARP.

  19. Functional implications of squamosal suture size in paranthropus boisei. (United States)

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


    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. Copyright © 2013 Wiley Periodicals, Inc.

  20. Stretch force guides finger-like pattern of bone formation in suture. (United States)

    Wu, Bo-Hai; Kou, Xiao-Xing; Zhang, Ci; Zhang, Yi-Mei; Cui, Zhen; Wang, Xue-Dong; Liu, Yan; Liu, Da-Wei; Zhou, Yan-Heng


    Mechanical tension is widely applied on the suture to modulate the growth of craniofacial bones. Deeply understanding the features of bone formation in expanding sutures could help us to improve the outcomes of clinical treatment and avoid some side effects. Although there are reports that have uncovered some biological characteristics, the regular pattern of sutural bone formation in response to expansion forces is still unknown. Our study was to investigate the shape, arrangement and orientation of new bone formation in expanding sutures and explore related clinical implications. The premaxillary sutures of rat, which histologically resembles the sutures of human beings, became wider progressively under stretch force. Micro-CT detected new bones at day 3. Morphologically, these bones were forming in a finger-like pattern, projecting from the maxillae into the expanded sutures. There were about 4 finger-like bones appearing on the selected micro-CT sections at day 3 and this number increased to about 18 at day 7. The average length of these projections increased from 0.14 mm at day 3 to 0.81 mm at day 7. The volume of these bony protuberances increased to the highest level of 0.12 mm3 at day 7. HE staining demonstrated that these finger-like bones had thick bases connecting with the maxillae and thin fronts stretching into the expanded suture. Nasal sections had a higher frequency of finger-like bones occuring than the oral sections at day 3 and day 5. Masson-stained sections showed stretched fibers embedding into maxillary margins. Osteocalcin-positive osteoblasts changed their shapes from cuboidal to spindle and covered the surfaces of finger-like bones continuously. Alizarin red S and calcein deposited in the inner and outer layers of finger-like bones respectively, which showed that longer and larger bones formed on the nasal side of expanded sutures compared with the oral side. Interestingly, these finger-like bones were almost paralleling with the direction

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

    Directory of Open Access Journals (Sweden)

    Vitor Mayer de Moura

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

  2. Single layer and multilayer wear resistant coatings of (Ti,Al)N: a review

    International Nuclear Information System (INIS)

    PalDey, S.; Deevi, S.C.


    periodicity of 5-10 nm allow creation of coatings with different properties than PVD deposited single layered thick coatings with columnar grain structure. A range of (Ti,Al)N based multilayers containing layers of (Ti,Al)CN, (Ti,Nb)N, TiN, AlN/TiN, CrN, Mo and WC are also reviewed. It is now possible to design new wear resistant or functional coatings based on a multilayer or a multicomponent system to meet the demanding applications of advanced materials

  3. Experimental study of the characteristics of a novel mesh suture. (United States)

    Dumanian, G A; Tulaimat, A; Dumanian, Z P


    The failure of sutures to maintain tissue in apposition is well characterized in hernia repairs. A mesh suture designed to facilitate tissue integration into and around the filaments may improve tissue hold and decrease suture pull-through. In vitro, the sutures were compared for resistance to pull-through in ballistics gel. In vivo, closure of midline laparotomy incisions was done with both sutures in 11 female pigs. Tissue segments were subsequently subjected to mechanical and histological testing. The mesh suture had tensile characteristics nearly identical to those of 0-polypropylene suture. Mesh suture demonstrated greater resistance to pull-through than standard suture (mean(s.d.) 4.27(0.42) versus 2.23(0.48) N; P tension closures. A new mesh suture design with a flexible macroporous outer wall and a hollow core allows the tissues to grow into the suture, improving early wound strength and decreasing suture pull-through. This technology may dramatically increase the reliability of high-tension closures, thereby preventing incisional hernia after laparotomy. As suture pull-through is a problem relevant to all surgical disciplines, numerous additional indications are envisioned with mesh suture formulations of different physical properties and materials. © 2015 The Authors. BJS published by John Wiley & Sons Ltd on behalf of BJS Society Ltd.

  4. A randomized clinical trial of knotless barbed suture vs conventional suture for closure of the uterine incision at cesarean delivery. (United States)

    Peleg, David; Ahmad, Ronan Said; Warsof, Steven L; Marcus-Braun, Naama; Sciaky-Tamir, Yael; Ben Shachar, Inbar


    Knotless barbed sutures are monofilament sutures with barbs cut into them. These sutures self-anchor, maintaining tissue approximation without the need for surgical knots. The hypothesis of this study was that knotless barbed suture could be used on the myometrium to close the hysterotomy at cesarean delivery. The objective was to compare uterine closure time, need for additional sutures, and blood loss between this and a conventional suture. This was a prospective, unblinded, randomized controlled trial conducted at the Ziv Medical Center, Zefat, Israel. The primary outcome was the length of time needed to close the uterine incision, which was measured from the start of the first suture on the uterus until obtaining uterine hemostasis. To minimize provider bias, women were randomized by sealed envelopes that were opened in the operating room just prior to uterine closure with either a bidirectional knotless barbed suture or conventional suture. Secondary outcomes included the number of additional hemostatic sutures needed and blood loss during incision closure. Patients were enrolled from August 2016 until March 2017. One hundred two women were randomized. Fifty-one had uterine closure with knotless barbed suture and 51 with conventional suture. The groups were similar for demographics as well as number of previous cesarean deliveries. Uterine closure time using the knotless barbed suture was significantly shorter than the conventional suture by a mean of 1 minute 43 seconds (P barbed sutures were associated with a lower need for hemostatic sutures (median 0 vs 1, P barbed suture is a reasonable alternative to conventional sutures because it reduced the closure time of the uterine incision. There was also less need for additional hemostatic sutures and slightly reduced estimated blood loss. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Evaluation of absorbable and nonabsorbable sutures for repair of achilles tendon rupture with a suture-guiding device. (United States)

    Kocaoglu, Baris; Ulku, Tekin Kerem; Gereli, Arel; Karahan, Mustafa; Turkmen, Metin


    The purpose of this study was to compare the functional and clinical results of Achilles tendon repairs with an Achilles tendon suture-guiding device using nonabsorbable versus absorbable sutures. We hypothesized that the absorbable suture would have clinical results comparable to those of the nonabsorbable suture for Achilles tendon repair with an Achilles tendon suture-guiding system. From January 2010 to September 2013, 48 consecutive patients who had sustained a spontaneous rupture of the Achilles tendon underwent operative repair with an Achilles tendon suture-guiding device using 2 different suture types. All ruptures were acute. The patients were divided equally into 2 groups according to suture type. In the nonabsorbable suture group, No. 2 braided nonabsorbable polyethylene terephthalate sutures were used, and in the absorbable suture group, braided absorbable polyglactin sutures were used. The average age of the patients was 38 years (range, 28-50 years). Functional outcome scores and complications were evaluated. All patients had an intact Achilles repair after surgery. The American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot clinical outcome scores were 98 (range, 90-100) in the nonabsorbable suture group and 96.8 (range, 87-100) in the absorbable suture group. All patients returned to their previous work. The absorbable suture group had fewer postoperative complications (0%) than the nonabsorbable suture group (12.5%) (P guiding system was associated with a lower incidence of suture reaction; however, functionally the results were not notably different from those using a traditional nonabsorbable suture. We conclude that repair with absorbable sutures is appropriate for Achilles tendon ruptures. Level II, prospective comparative study. © The Author(s) 2015.

  6. Magneto-electroluminescence effects in the single-layer organic light-emitting devices with macrocyclic aromatic hydrocarbons

    Directory of Open Access Journals (Sweden)

    S.-T. Pham


    Full Text Available Magneto-electroluminescence (MEL effects are observed in single-layer organic light-emitting devices (OLEDs comprising only macrocyclic aromatic hydrocarbons (MAHs. The fluorescence devices were prepared using synthesized MAHs, namely, [n]cyclo-meta-phenylene ([n]CMP, n = 5, 6. The MEL ratio of the resulting OLED is 1%–2% in the spectral wavelength range of 400-500 nm, whereas it becomes negative (−1.5% to −2% in the range from 650 to 700 nm. The possible physical origins of the sign change in the MEL are discussed. This wavelength-dependent sign change in the MEL ratio could be a unique function for future single-layer OLEDs capable of magnetic-field-induced color changes.

  7. Novel single-layer gas diffusion layer based on PTFE/carbon black composite for proton exchange membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Chen-Yang, Y.W.; Hung, T.F.; Yang, F.L. [Department of Chemistry and Center for Nanotechnology, Chung Yuan Christian University, Chung-Li 32023 (China); Huang, J. [Yeu Ming Tai Chemical Industrial Co., Ltd, Taichung 40768 (China)


    A series of poly(tetrafluoroethylene)/carbon black composite-based single-layer gas diffusion layers (PTFE/CB-GDLs) for proton exchange membrane fuel cell (PEMFC) was successfully prepared from carbon black and un-sintered PTFE, which included powder resin and colloidal dispersion, by a simple inexpensive method. The scanning electron micrographs of PTFE/CB-GDLs indicated that the PTFE resins were homogeneously dispersed in the carbon black matrix and showed a microporous layer (MPL)-like structure. The as-prepared PTFE/CB-GDLs exhibited good mechanical property, high gas permeability, and sufficient water repellency. The best current density obtained from the PEMFC with the single-layer PTFE/CB-GDL was 1.27 and 0.42 A cm{sup -2} for H{sub 2}/O{sub 2} and H{sub 2}/air system, respectively. (author)

  8. Structure and Electronic Properties of In Situ Synthesized Single-Layer MoS2 on a Gold Surface

    DEFF Research Database (Denmark)

    Sørensen, Signe Grønborg; Füchtbauer, Henrik Gøbel; Tuxen, Anders Kyrme


    with scanning tunneling microscopy and X-ray photoelectron spectroscopy characterization of two-dimensional single-layer islands of MoS2 synthesized directly on a gold single crystal substrate. Thanks to a periodic modulation of the atom stacking induced by the lattice mismatch, we observe a structural buckling...... structure appears modified at the band gap edges. This electronic effect is further modulated by the moiré periodicity and leads to small substrate-induced electronic perturbations near the conduction band minimum in the band gap of MoS2. The results may be highly relevant in the context of nanopatterned......When transition metal sulfides such as MoS2 are present in the single-layer form, the electronic properties change in fundamental ways, enabling them to be used, e.g., in two-dimensional semiconductor electronics, optoelectronics, and light harvesting. The change is related to a subtle modification...

  9. A meta-analytic review of the effectiveness of single-layer clothing in preventing exposure from pesticide handling. (United States)

    Miguelino, Eric S


    This review summarizes available information on the penetration of pesticides through single-layer clothing by pesticide handlers and introduces epidemiological and observational studies on pesticide exposure. The data for this report were taken from peer-reviewed articles, publicly available government reports, and publicly available government reviews of registrant-submitted data and information. The arithmetic mean of calculated clothing penetration was obtained for various parts of the body (upper arm, lower arm, chest/torso, back/torso, upper leg, and lower leg) that were exposed to pesticide. The range of pesticide penetration to the various parts of the body through single-layer clothing during mixing, loading, and application (MLA) activities was found to be 6.2% ± 5.7% to 21.4% ± 6.7%, which demonstrates a potential for increased and unintentional pesticide exposures. Based on this evaluation, some accepted default values for protection against pesticide exposure may be overestimated.

  10. Spin-dependent electron-phonon coupling in the valence band of single-layer WS2

    DEFF Research Database (Denmark)

    Hinsche, Nicki Frank; Ngankeu, Arlette S.; Guilloy, Kevin


    The absence of inversion symmetry leads to a strong spin-orbit splitting of the upper valence band of semiconducting single-layer transition-metal dichalchogenides such as MoS2 or WS2. This permits a direct comparison of the electron-phonon coupling strength in states that only differ by their spin....... Here, the electron-phonon coupling in the valence band maximum of single-layer WS2 is studied by first-principles calculations and angle-resolved photoemission. The coupling strength is found to be drastically different for the two spin-split branches, with calculated values of λK=0.0021 and 0.......40 for the upper and lower spin-split valence band of the freestanding layer, respectively. This difference is somewhat reduced when including scattering processes involving the Au(111) substrate present in the experiment but it remains significant, in good agreement with the experimental results....

  11. Mechanical performance of gamma irradiated surgical sutures

    Energy Technology Data Exchange (ETDEWEB)

    Pino, Eddy S.; Rela, Paulo P. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)


    Surgical sutures are medical devices made of natural or synthetic polymeric materials that, due to its end-use, have to be sterilized. Historically, the sterilization by heat or using ethylene oxide had presented so numerous drawbacks that today the non-pollutant radiation sterilization has become a well established sterilization process, that brings, environmental, technical, and economical advantages. The amount of irradiation doses required for sterilization of health care products is 25 kGy in most instances to achieve the necessary sterility assurance level. As high energy radiation produces modifications in the molecular structure of organic materials with changes in its mechanical properties, the aim of this work was to evaluate the mechanical behavior of surgical sutures under irradiation. Silk, polyamide and catgut sutures were gamma irradiated up to doses of 50 kGy in an industrial irradiation sterilization plant. Afterwards, these sutures were mechanical tested for tensile strength under knot following the specifications of the NBR13904 draft standard, using the CTRD-INSTRON at IPEN. The mechanical lab results show that sutures made of Silk and Polyamide do not present any change in their mechanical performance up to the dose of 50 kGy. On the other hand, Catgut present mechanical stability up to 30 kGy and afterwards, a slight decrease in its tensile strength was detected. (author)

  12. Celebrity arcade suture blepharoplasty for double eyelid. (United States)

    Liao, Wen-Chieh; Tung, Tung-Chain; Tsai, Tzong-Ru; Wang, Chia-Yi; Lin, Chiu-Hwa


    In Taiwan, double-eyelid surgery is the most popular cosmetic surgical procedure. The technique preferred by plastic surgeons is the incision method because it is believed that this method can provide stable double-eyelid results. It is the authors' observation that patients prefer an invagination fold rather than a significantly high fold. Suture blepharoplasty may create a relatively even and symmetric invagination fold. In the past, the major disadvantage of the suture technique has been the opinion that the double fold fades away. The celebrity arcade suture (CAS) technique was applied in double-eyelid operations. The CAS technique includes three major techniques: stabbing incision, transtarsal suture, and bridge connection. The whole procedure can be completed in 15 min. From June 2001 to November 2004, 312 patients underwent the CAS technique. Of the 312 patients who underwent the CAS technique, 5 required a revisit, with 3 of these returning patients reporting fold disappearance. These three patients received repeat suture procedures. The findings show that the CAS technique is a reliable method for establishing a smooth, constant, and symmetric double eyelid, and that CAS requires only a short recovery time.

  13. Single-layer ZnS supported on Au(111): A combined XPS, LEED, STM and DFT study (United States)

    Deng, Xingyi; Sorescu, Dan C.; Lee, Junseok


    Single-layer of ZnS, consisting of one atomic layer of ZnS(111) plane, has been grown on Au(111) and characterized using X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED) and scanning tunneling microscopy (STM). While the LEED measurement indicates a coincidence structure of ZnS-(3×3)/Au(111)-(4×4), high resolution STM images reveal hexagonal unit cells of 6.7×6.7 Å2 and 11.6×11.6 Å2, corresponding to √3 and 3 times the unit cell of the ideal zincblende ZnS-(1×1), respectively, depending on the tunneling conditions. Calculations based on density functional theory (DFT) indicate a significantly reconstructed non-planar structure of ZnS single-layer on Au(111) with 2/3 of the S anions being located nearly in the plane of the Zn cations and the rest 1/3 of the S anions protruding above the Zn plane. The calculated STM image shows similar characteristics to those of the experimental STM image. Additionally, the DFT calculations reveal the different bonding nature of the S anions in ZnS single-layer supported on Au(111).

  14. [Predictable tip suture techniques in rhinoplasty]. (United States)

    Papel, I D


    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.

  15. Intracorporal suturing--driving license necessary? (United States)

    Romero, P; Brands, O; Nickel, F; Müller, B; Günther, P; Holland-Cunz, S


    Intracorporeal suturing and knot tying (ICKT) in minimal invasive surgery (MIS) represents a key skill for advanced procedures. Different methods exist for measuring knot quality and performance, but the heterogeneity of these methods makes direct comparisons difficult. The aim of this study is to compare the quality of a laparoscopic knot to one that is performed open. To compare open and laparoscopic knot-tying methods we used a surgeon's square knot. For laparoscopic knot tying we used a Pelvitrainer. The 32 participants were divided among 4 groups of different skill levels. Group 1 consisted of 6 senior physicians. Group 2 was made up of 10 first to fourth year interns. Groups 3 and 4 contained 16 medical students who had never performed either laparoscopic procedures or open sutures before. Group 3 participants received a 1-hour hands-on training in suturing, whereas group 4 participants received no prior training. Total time, knot quality, suture placement accuracy, and performance defined the parameters for assessment in this study. All participants, irrespective of education level were inferior in ICKT compared to open suturing. Only Group 1 showed no significant difference in knot quality and accuracy between the open and laparoscopic suture performance. It is well documented that psychomotor skills need to be developed before more advanced skills can be put into practice. Training centres for minimally invasive surgery should be an integral part of surgical education. The variables in our study are meaningful and easy to implement. They can be used to measure personal progress and as objective parameters in the development of laparoscopic trainee education. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. 21 CFR 878.5020 - Nonabsorbable polyamide surgical suture. (United States)


    ... polyamide surgical suture. (a) Identification. Nonabsorbable polyamide surgical suture is a nonabsorbable, sterile, flexible thread prepared from long-chain aliphatic polymers Nylon 6 and Nylon 6,6 and is...

  17. 21 CFR 878.4930 - Suture retention device. (United States)


    ... button, or a suture bolster, intended to aid wound healing by distributing suture tension over a larger area in the patient. (b) Classification. Class I (general controls). The device is exempt from the...

  18. 21 CFR 878.4494 - Absorbable poly(hydroxybutyrate) surgical suture produced by recombinant DNA technology. (United States)


    ... recombinant DNA technology. (a) Identification. An absorbable poly(hydroxybutyrate) surgical suture is an... produced by recombinant DNA technology. 878.4494 Section 878.4494 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY...

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

    LENUS (Irish Health Repository)

    Bonham, Joseph


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

  20. Analgesia para a sutura artroscópica do manguito rotador: estudo comparativo entre o bloqueio interescalênico do plexo braquial e o bloqueio da bursa subacromial contínuo Management of pain after the rotator cuff arthroscopic suture: comparative study among the interescalenic blockade and the continuous intrabursal infusion

    Directory of Open Access Journals (Sweden)

    Alexandre Almeida


    analyzed. Group I comprised patients who received interescalenic blockade with 0.75% ropivacaine. In group II, the same blockade was added with 150 µg of clonidine. In group III, a 30 ml bolus of 0.75% ropivacaine was administered to infiltrate the arthroscopic portals and directly in the subacromial space, followed by a continuous infusion of 0.2% ropivacaine with an infusion pump. The patients were submitted to the medication of the EAV analogue-visual scale 24 hours after the procedure. The variables studied were EAV, gender, size of the lesion, need of internal capsulotomy, and prevalence of side effects. The study evaluated 196 patients, 51 of whom were excluded, thus giving a total " n" = 145 patients. The total of patients in group I was 65, in group II, 19, and in group III, 61. RESULTS: The mean EAV index found for group I was 3.88 ± 1,737 (3; in group II, it was 3.8 ± 1.6 (3, and in group III, 1.95 ± 1.6 (2. There was a significant difference when comparing group I to group III (p < 0.001 and when comparing group II to group III (p < 0.001 suggesting less pain felt by patients in group III. There was no pain perception difference between genders (p = 0.700 and among the different sizes of rotator cuff lesion (p = 0.546. There was a pain perception difference between patients that were and those that were not submitted to internal capsulotomy (p = 0.038. There was reduced prevalence of nausea and/or vomiting (p = 0.089 and of pruritus (p = 0.092 in group III as compared to groups I and II. CONCLUSIONS: The protocol of postoperative analgesia with continuous infusion of ropivacaine showed that it is better than the protocols using morphine after the end of the interescalenic blockade effects. There was no difference in pain perception between the genders and according to different sizes of sutured lesions. There was a difference in pain perception by the patients who had and those who have not had internal capsulotomy. The rate of side effects was similar among

  1. 21 CFR 878.5010 - Nonabsorbable polypropylene surgical suture. (United States)


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

  2. Thyroid hormone action on rat calvarial sutures. (United States)

    Akita, S; Nakamura, T; Hirano, A; Fujii, T; Yamashita, S


    To clarify the effect of thyroid hormone on the calvarial sutures, the morphology, histology, and bone mineral density were analyzed in thyroid hormone-injected rats. A total of 80 female Wistar rats at the age of 10 days were divided into 2 groups; the triiodothyronine (T3)-treated rats (n = 40, T3 100 micrograms/kg body weight/day) were maintained under the same conditions as controls (n = 40, saline-vehicle only), and both were sacrificed at 50, 80, and 200 experimental days, respectively. T3-treated animals showed smaller values of lambda-asterion and pterion-bregma distances at the various periods of examination, resulting in smaller sizes in right-left direction of the skull. The sagittal suture distance in the skull specimens observed by Goldner's staining (fibrous tissue content) appeared smaller and the osseous margin widths greatly increased in the T3-treated rats. Fluorescent microscopy revealed that the tetracycline-calcein double labelings were not interrupted from the periosteal to the endosteal areas in any specimens indicating the scantiness of osteoclastic activity in the suture areas. Mineral apposition rates at the osseous edges of the suture were significantly increased in the T3-treated rats (p < 0.01 at the age of 90 days). The distance between the second labels and the distance between the first labels were significantly larger in the T3-treated rats. Bone mineral density (BMD) measurement showed that the T3 administration decreased only the calvarial BMD at the age of 210 days (p < 0.01), but did not decrease lumbar or femur BMD. This experiment demonstrated clear evidence of excess thyroid hormone action on the early narrowing of the sagittal suture in infantile hyperthyroid rats, probably due to the enhanced osteogenic activity caused by the hormone.

  3. Peculiarities of superconductivity in the single-layer FeSe /SrTi O3 interface (United States)

    Gor'kov, Lev P.


    Observation of replica bands in the angle-resolved photoemission spectroscopy (ARPES) spectra of single-layer FeSe on a strontium titanate substrate revealed a phonon component contribution to mechanisms behind its high-Tc superconductivity. We study the interaction of the in-layer FeSe electrons with the electric potential of the longitudinal (LO) modes at the surface of bulk SrTi O3 . A two-dimensional system of charges at the FeSe /SrTi O3 interface includes both the itinerant and the immobile electrons. The latter significantly change the interface characteristics, increasing screening at the substrate surface and thereby reducing the strength of the electron-LO-phonon interaction. In what follows, the dielectric constant serves as a free parameter and is determined using the ARPES measurements of the replicas. Two-dimensional Coulomb screening is accounted for in the random-phase approximation. It is shown that the model is applicable over the entire range of the parameters typical for current experiments. The estimates from this model make possible the conclusion that the LO-phonon-mediated pairing alone cannot account for the temperatures of the superconducting transitions Tc in the single-layer FeSe /SrTi O3 reported in these experiments. This does not exclude that the LO-phonon mechanisms can become more significant in differently and better prepared single-layer FeSe films. Available experiments are briefly discussed. Thus far no measurements exist on the dependence of Tc on the concentration of electrons doped into the in-layer FeSe band.

  4. [Observation of single-layered inverted internal limiting membrane flap technique for macular hole with retinal detachment in high myopia]. (United States)

    Xu, C Z; Wu, J H; He, J W; Feng, C


    Objective: To compare the outcome of pars plana vitrectomy (PPV) with a single-layered inverted internal limiting membrane (ILM) flap versus PPV with ILM peeling for the treatment of macular hole associated retinal detachment (MHRD) in high myopia. Methods: In a retrospective cohort study, PPV with 2 kinds of adjuvant surgical procedures were used in 35 moderately high myopia eyes with MHRD. These eyes were divided into 2 groups: group 1 (17 eyes) receiving PPV and ILM peeling and group 2 (18 eyes) receiving PPV with a single-layered inverted ILM flap. Anatomical reattachment of the retina, macular hole closure, and best-corrected visual acuity (BCVA) were measured at 6 months after surgery. Results: The retina was successfully reattached in all cases. The difference of the retinal reattachment rate between the two groups was not statistically significant (Fisher's exact test, P= 1.000). The rate of macular hole closure was 47.1% in group 1 (8 eyes) and 88.9% in group 2 (16 eyes). The difference of the macular hole closure rate between the two groups was statistically significant (Fisher's exact test, P= 0.012). Significant improvement in logarithm of minimal angle of resolution (logMAR) BCVA was achieved in both groups. There was no difference in the initial, final, or improved logMAR BCVA in the 2 groups. Conclusion: Single-layered inverted ILM flap technique effectively helps close the macular hole in moderately high myopia with MHRD. This may prevent the possible redetachment from the macular hole. (Chin J Ophthalmol, 2017, 53: 338 - 343) .

  5. Septal anchoring suture: a key suture to improve the nasolabial symmetry in unilateral cheiloplasty. (United States)

    Lu, T-C; Filson, S; Yao, C-F; Chen, P K-T


    Since 2008, a septal anchoring suture has been used in unilateral cleft lip repair at Chang Gung Memorial Hospital in order to stabilize the lateral lip centrally. This study compared the symmetry of two groups of patients: those treated with and without an anchoring suture. Multiple standardized direct and photographic facial measurements were performed on the faces of all patients pre-cheiloplasty and at 5 years post-cheiloplasty. The degree of nasolabial symmetry was evaluated by comparing the ratios of measurements of the cleft vs. non-cleft sides. The ratio of change in these measurements was also compared postoperatively. The vertical lip length ratio approached 1 in the septal anchoring suture group, which differed significantly from the group without the suture (0.968 vs. 0.873, P<0.001). As expected, the horizontal lip length and central lip height ratios showed no statistically significant change. The ratio of change from pre- to postoperative also showed a significant improvement (P=0.028) in the vertical lip length of the group with the septal anchoring suture compared to the one without. The septal anchoring suture is a useful method to correct the tendency of the lip to shift to the cleft side. Copyright © 2018 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  6. Self-assembly surface modified indium-tin oxide anodes for single-layer light-emitting diodes

    CERN Document Server

    Morgado, J; Charas, A; Matos, M; Alcacer, L; Cacialli, F


    We study the effect of indium-tin oxide surface modification by self assembling of highly polar molecules on the performance of single-layer light-emitting diodes (LEDs) fabricated with polyfluorene blends and aluminium cathodes. We find that the efficiency and light-output of such LEDs is comparable to, and sometimes better than, the values obtained for LEDs incorporating a hole injection layer of poly(3,4-ethylene dioxythiophene) doped with polystyrene sulphonic acid. This effect is attributed to the dipole-induced work function modification of indium-tin oxide.

  7. Effect of ethanethiolate spacer on morphology and optical responses of Ag nanoparticle array-single layer graphene hybrid systems

    Czech Academy of Sciences Publication Activity Database

    Sutrová, Veronika; Šloufová, I.; Melníková Komínková, Zuzana; Kalbáč, Martin; Pavlova, Ewa; Vlčková, B.


    Roč. 33, č. 50 (2017), s. 14414-14424 ISSN 0743-7463 R&D Projects: GA ČR(CZ) GA15-01953S; GA MŠk(CZ) LM2015073 Grant - others:GA MŠk(CZ) CZ.02.1.01/0.0/0.0/16_013/0001821 Institutional support: RVO:61389013 ; RVO:61388955 Keywords : Ag nanoparticle * single layer graphene * ethanethiol Subject RIV: JI - Composite Materials; CF - Physical ; Theoretical Chemistry (UFCH-W) OBOR OECD: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics; Physical chemistry (UFCH-W) Impact factor: 3.833, year: 2016

  8. Self-assembly surface modified indium-tin oxide anodes for single-layer light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Morgado, Jorge [Instituto de Telecomunicacoes and Departamento de Engenharia Quimica, Instituto Superior Tecnico, Avenida Rovisco Pais, P-1049-001 Lisbon (Portugal); Barbagallo, Nunzio [Instituto de Telecomunicacoes and Departamento de Engenharia Quimica, Instituto Superior Tecnico, Avenida Rovisco Pais, P-1049-001 Lisbon (Portugal); Charas, Ana [Instituto de Telecomunicacoes and Departamento de Engenharia Quimica, Instituto Superior Tecnico, Avenida Rovisco Pais, P-1049-001 Lisbon (Portugal); Matos, Manuel [Departamento de Engenharia Quimica, Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emidio Navarro-1, P-1949-001 Lisbon (Portugal); Alcacer, Luis [Instituto de Telecomunicacoes and Departamento de Engenharia Quimica, Instituto Superior Tecnico, Avenida Rovisco Pais, P-1049-001 Lisbon (Portugal); Cacialli, Franco [Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT (United Kingdom)


    We study the effect of indium-tin oxide surface modification by self assembling of highly polar molecules on the performance of single-layer light-emitting diodes (LEDs) fabricated with polyfluorene blends and aluminium cathodes. We find that the efficiency and light-output of such LEDs is comparable to, and sometimes better than, the values obtained for LEDs incorporating a hole injection layer of poly(3,4-ethylene dioxythiophene) doped with polystyrene sulphonic acid. This effect is attributed to the dipole-induced work function modification of indium-tin oxide.

  9. Model for a collimated spin-wave beam generated by a single-layer spin torque nanocontact (United States)

    Hoefer, M. A.; Silva, T. J.; Stiles, M. D.


    A model of spin-torque-induced magnetization dynamics based on semiclassical spin diffusion theory for a single-layer nanocontact is presented. The model incorporates effects due to the current-induced Oersted field and predicts the generation of a variety of spatially dependent, coherent, precessional magnetic wave structures. Directionally controllable collimated spin-wave beams, vortex spiral waves, and localized standing waves are found to be excited by the interplay of the Oersted field and the orientation of an applied field. These fields act as a spin-wave “corral” around the nanocontact that controls the propagation of spin waves in certain directions.

  10. Anisotropic Young's Modulus for Single-Layer Black Phosphorus: The Third Principle Direction Besides Armchair and Zigzag


    Jiang, Jin-Wu


    We derive an analytic formula for the Young's modulus in single-layer black phosphorus using the valence force field model. By analyzing the directional dependence for the Young's modulus, we explore the third principle direction with direction angle phi_tp = 0.268pi besides armchair and zigzag directions. The maximum Young's modulus value is in the third principle direction. More specifically, the Young's modulus is 52.2 N/m, 85.4 N/m, and 111.4 N/m in the armchair direction, zigzag directio...

  11. Acute Achilles tendon rupture: Mini-incision repair with double-Tsuge loop suture vs. open repair with modified Kessler suture. (United States)

    Fu, Chongyang; Qu, Wei


    Achilles tendon rupture is a common injury of the foot and ankle. However, the optimal treatment strategy for Achilles tendon rupture is still not established. This study was conducted to compare the efficacy and complications of mini-incision repair with double-Tsuge loop sutures and open repair with modified Kessler sutures. We evaluated data from 60 patients with acute closed Achilles tendon ruptures who underwent mini-incision repair with double-Tsuge loop sutures (n = 30) or open repair with modified Kessler sutures (n = 30) from 2006 to 2010 in an ongoing prospective study conducted by us and have finished at least 18-month follow-up or finished the study. The AOFAS Ankle-Hindfoot score, ATRS, maximal ankle range of motion and the time to achieve 20 continuous single heel raises after operation were recorded to compare the efficacy. The complications were also evaluated. During a mean follow-up of 25 months after surgery, the time to achieve 20 continuous single heel raises after operation of patients in Group Mini was significantly shorter than patients in Group Open. Moreover, the mini-incision with double-Tsuge repair was associated with a significantly shorter operating time, smaller incision length, and lower rate of complications. The mini-incision with double-Tsuge suture method in our study was shown to provide earlier strength recovery, as well as shorter operation time, less complications and improved cosmetic appearance. Copyright © 2014 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

  12. The European Academy laparoscopic “Suturing Training and Testing’’ (SUTT) significantly improves surgeons’ performance (United States)

    Sleiman, Z.; Tanos, V.; Van Belle, Y.; Carvalho, J.L.; Campo, R.


    The efficiency of suturing training and testing (SUTT) model by laparoscopy was evaluated, measuring the suturingskill acquisition of trainee gynecologists at the beginning and at the end of a teaching course. During a workshop organized by the European Academy of Gynecological Surgery (EAGS), 25 participants with three different experience levels in laparoscopy (minor, intermediate and major) performed the 4 exercises of the SUTT model (Ex 1: both hands stitching and continuous suturing, Ex 2: right hand stitching and intracorporeal knotting, Ex 3: left hand stitching and intracorporeal knotting, Ex 4: dominant hand stitching, tissue approximation and intracorporeal knotting). The time needed to perform the exercises is recorded for each trainee and group and statistical analysis used to note the differences. Overall, all trainees achieved significant improvement in suturing time (p psychomotor skills, surgery, teaching, training suturing model. PMID:26977264

  13. Comparison of barbed unidirectional suture with figure-of-eight standard sutures in vaginal cuff closure in total laparoscopic hysterectomy. (United States)

    Karacan, Tolga; Ozyurek, Eser; Usta, Taner; Odacilar, Eylem; Hanli, Ulviye; Kovalak, Ebru; Dayan, Huseyin


    The aim of the study was to compare postoperative vaginal cuff complications due to the use of barbed sutures (V-Loc™ 180 unidirectional suture; Covidien, Mansfield, MA) and standard braided sutures (Vicryl ® ; Ethicon Inc., Somerville, MA) during vaginal cuff closure of patients undergoing a total laparoscopic hysterectomy (TLH) due to benign diseases. Eighty-nine patients were in the standard suture group and 208 patients were included in the barbed suture group. Vaginal cuff dehiscence was identified in only three (3.3%) patients within the standard suture group and none in the barbed suture group. Five (5.6%) patients in the standard suture group and two (0.9%) patients in the barbed suture group developed postoperative cuff infection/cellulitis. Duration of the surgery was significantly shorter in the barbed suture group than in the standard suture group (p barbed suture, which is used during TLH for vaginal cuff closure, is an applicable, safe and tolerable alternative to a standard suture. IMPACT STATEMENT What is already known on this subject: Barbed sutures are a relatively new type of suture that include sharp barbs inserted on monofilament material in various configurations, and are used for approximating tissues without any need for surgical knotting. They have increasingly been used in obstetrics and gynaecology in recent years, particularly in total laparoscopic hysterectomy and laparoscopic myomectomy. At present, there are a limited number of studies of V-Loc™ suture in the literature. What the results of this study add: We demonstrated that barbed sutures used for enabling vaginal cuff integrity did not cause major morbidity and mortality for the patient. We suggest that V-Loc™ 180 barbed sutures offer a practical, safe and tolerable alternative for surgeons because they are easy to use, do not cause a significant increase in vaginal cuff complications, and shorten the operating time. Our study with V-Loc™ 180 unidirectional barbed

  14. Growing vertical ZnO nanorod arrays within graphite: efficient isolation of large size and high quality single-layer graphene. (United States)

    Ding, Ling; E, Yifeng; Fan, Louzhen; Yang, Shihe


    We report a unique strategy for efficiently exfoliating large size and high quality single-layer graphene directly from graphite into DMF dispersions by growing ZnO nanorod arrays between the graphene layers in graphite.

  15. Biomechanical Dynamics of Cranial Sutures during Simulated Impulsive Loading

    Directory of Open Access Journals (Sweden)

    Z. Q. Zhang


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

  16. Current manufacturing processes of drug-eluting sutures. (United States)

    Champeau, Mathilde; Thomassin, Jean-Michel; Tassaing, Thierry; Jérôme, Christine


    Drug-eluting sutures represent the next generation of surgical sutures since they fulfill their mechanical functions but also deliver the drug in their vicinity after implantation. These implants are produced by a variety of manufacturing processes. Drug-eluting sutures represent the next generation of surgical sutures since they fulfill their mechanical functions but also deliver the drug in their vicinity after implantation. These implants are produced by a variety of manufacturing processes. Two general approaches can be followed: (i) the ones that add the API into the material during the manufacturing process of the suture and (ii) the ones that load the API to an already manufactured suture. Areas covered: This review provides an overview of the current manufacturing processes for drug-eluting suture production and discusses their benefits and drawbacks depending on the type of drugs. The mechanical properties and the drug delivery profile of drug-eluting sutures are highlighted since these implants must fulfill both criteria. Expert opinion: For limited drug contents, melt extrusion and electrospinning are the emerging processes since the drug is added during the suture manufacture process. Advantageously, the drug release profile can be tuned by controlling the processing parameters specific to each process and the composition of the drug-containing polymer. If high drug content is targeted, the coating or grafting of a drug layer on a pre-manufactured suture allows for preservation of the tensile strength requirements of the suture.

  17. Cost analysis of stapling versus suturing for skin closure. (United States)

    Orlinsky, M; Goldberg, R M; Chan, L; Puertos, A; Slajer, H L


    A randomized, prospective study was performed to test the null hypothesis that there is no difference between the cost of stapling and suturing for skin closure of selected linear lacerations. Appropriate wounds were randomly assigned to be closed by staples or sutures. Wound lengths, skin closure times, and the number of staples or the number and types of sutures used were recorded. Costs for materials and labor were calculated. The average total cost per case was $17.69 (with suture kit) and $7.84 (without suture kit) for the staple Group compared with $21.58 for the suture Group (P = .0001 for each). It is concluded that stapling is less costly than suturing and that the advantage appears to increase as laceration length increases.

  18. Analytical and molecular dynamics studies on the impact loading of single-layered graphene sheet by fullerene (United States)

    Hosseini-Hashemi, Shahrokh; Sepahi-Boroujeni, Amin; Sepahi-Boroujeni, Saeid


    Normal impact performance of a system including a fullerene molecule and a single-layered graphene sheet is studied in the present paper. Firstly, through a mathematical approach, a new contact law is derived to describe the overall non-bonding interaction forces of the "hollow indenter-target" system. Preliminary verifications show that the derived contact law gives a reliable picture of force field of the system which is in good agreements with the results of molecular dynamics (MD) simulations. Afterwards, equation of the transversal motion of graphene sheet is utilized on the basis of both the nonlocal theory of elasticity and the assumptions of classical plate theory. Then, to derive dynamic behavior of the system, a set including the proposed contact law and the equations of motion of both graphene sheet and fullerene molecule is solved numerically. In order to evaluate outcomes of this method, the problem is modeled by MD simulation. Despite intrinsic differences between analytical and MD methods as well as various errors arise due to transient nature of the problem, acceptable agreements are established between analytical and MD outcomes. As a result, the proposed analytical method can be reliably used to address similar impact problems. Furthermore, it is found that a single-layered graphene sheet is capable of trapping fullerenes approaching with low velocities. Otherwise, in case of rebound, the sheet effectively absorbs predominant portion of fullerene energy.

  19. First-principles study of thermal expansion and thermomechanics of single-layer black and blue phosphorus

    International Nuclear Information System (INIS)

    Sun, Hongyi; Liu, Gang; Li, Qingfang; Wan, X.G.


    The linear thermal expansion coefficients (LTEC) and thermomechanics of single-layer black and blue phosphorus are systematically studied using first-principles based on quasiharmonic approximation. We find the thermal expansion of black phosphorus is very anisotropic. The LTEC along zigzag direction has a turning from negative to positive at around 138 K, while the LTEC along armchair direction is positive (except below 8 K) and about 2.5 times larger than that along zigzag direction at 300 K. For blue phosphorus, the LTEC is negative in the temperature range from 0 to 350 K. In addition, we find that the Young's modulus and Poisson's ratio of black phosphorus along zigzag direction are 4 to 5 times larger than those along armchair direction within considered temperature range, showing a remarkable anisotropic in-plane thermomechanics property. The mechanisms of these peculiar thermal properties are also explored. This work provides a theoretical understanding of the thermal expansion and thermomechanics of this single layer phosphorus family, which will be useful in nanodevices. - Highlights: • The thermal properties of black and blue phosphorus are studied. • Black phosphorus shows remarkable anisotropic thermal expansion and thermomechanics properties. • Blue phosphorus shows novel negative thermal expansion. • The thermal expansion properties are well analyzed by grüneisen theory.

  20. A development of simulation and analytical program for through-diffusion experiments for a single layer of diffusion media

    International Nuclear Information System (INIS)

    Sato, Haruo


    A program (TDROCK1. FOR) for simulation and analysis of through-diffusion experiments for a single layer of diffusion media was developed. This program was made by Pro-Fortran language, which was suitable for scientific and technical calculations, and relatively easy explicit difference method was adopted for an analysis. In the analysis, solute concentration in the tracer cell as a function of time that we could not treat to date can be input and the decrease in the solute concentration as a function of time by diffusion from the tracer cell to the measurement cell, the solute concentration distribution in the porewater of diffusion media and the solute concentration in the measurement cell as a function of time can be calculated. In addition, solution volume in both cells and diameter and thickness of the diffusion media are also variable as an input condition. This simulation program could well explain measured result by simulating solute concentration in the measurement cell as a function of time for case which apparent and effective diffusion coefficients were already known. Based on this, the availability and applicability of this program to actual analysis and simulation were confirmed. This report describes the theoretical treatment for the through-diffusion experiments for a single layer of diffusion media, analytical model, an example of source program and the manual. (author)

  1. Alkali (Li, K and Na) and alkali-earth (Be, Ca and Mg) adatoms on SiC single layer (United States)

    Baierle, Rogério J.; Rupp, Caroline J.; Anversa, Jonas


    First-principles calculations within the density functional theory (DFT) have been addressed to study the energetic stability, and electronic properties of alkali and alkali-earth atoms adsorbed on a silicon carbide (SiC) single layer. We observe that all atoms are most stable (higher binding energy) on the top of a Si atom, which moves out of the plane (in the opposite direction to the adsorbed atom). Alkali atoms adsorbed give raise to two spin unpaired electronic levels inside the band gap leading the SiC single layer to exhibit n-type semiconductor properties. For alkaline atoms adsorbed there is a deep occupied spin paired electronic level inside the band gap. These finding suggest that the adsorption of alkaline and alkali-earth atoms on SiC layer is a powerful feature to functionalize two dimensional SiC structures, which can be used to produce new electronic, magnetic and optical devices as well for hydrogen and oxygen evolution reaction (HER and OER, respectively). Furthermore, we observe that the adsorption of H2 is ruled by dispersive forces (van der Waals interactions) while the O2 molecule is strongly adsorbed on the functionalized system.

  2. Design of single-layer high-efficiency transmitting phase-gradient metasurface and high gain antenna (United States)

    Zhang, Di; Yang, Xiaoqing; Su, Piqiang; Luo, Jiefang; Chen, Huijie; Yuan, Jianping; Li, Lixin


    In this paper, based on rotation phase-gradient principle, a single-layer, high-efficiency transmitting metasurface is designed and applied to high-gain antenna. In the case of circularly polarized incident wave, the PCR (polarization conversions ratio) of the metasurface element is greater than 90% in the band of 9.11–10.48 GHz. The transmitting wave emerges an anomalous refraction when left-handed circularly polarized wave are incident perpendicularly to the 1D phase-gradient metasurface, which is composed of cycle arrangement of 6 units with step value of 30°. The simulated anomalous refraction angle is 40.1°, coincided with the theoretical design value (40.6°). For further application, the 2D focused metasurface is designed to enhance the antenna performance while the left-handed circularly polarized antenna is placed at the focus. The simulated max gain is increased by 12 dB (182%) and the half-power beamwidth is reduced by 74.6°. The measured results are coincided with the simulations, which indicates the antenna has high directivity. The designed single-layer transmission metasurface has advantages of thin thickness (only 1.5 mm), high efficiency and light weight, and will have important application prospects in polarization conversion and beam control.

  3. Suture Choice in Lumbar Dural Closure Contributes to Variation in Leak Pressures: Experimental Model. (United States)

    Ghobrial, George M; Maulucci, Christopher M; Viereck, Matthew J; Beygi, Sara; Chitale, Ameet; Prasad, Srinivas; Jallo, Jack; Heller, Joshua; Sharan, Ashwini D; Harrop, James S


    Open-label laboratory investigational study; non-animal surgical simulation. The authors perform a comparison of dural closure strength in a durotomy simulator across 2 different suture materials. Incidental durotomy leading to persistent cerebrospinal fluid leak adds considerable morbidity to spinal procedures, often complicating routine elective lumbar spinal procedures. Using an experimental durotomy simulation, the authors compare the strength of closure using Gore-Tex with other suture types and sizes, using various closure techniques. A comparison of dural closures was performed through an analysis of the peak pressure at which leakage occurred from a standardized durotomy closure in an established cerebrospinal fluid repair model with a premade L3 laminectomy. Nurolon was compared with Gore-Tex sutures sizes (for Gore-Tex, CV-6/5-0 and CV-5/4-0 was compared with Nurolon 4-0, 5-0, and 6-0). Thirty-six trials were performed with Nurolon 4-0, 5-0, and 6-0, whereas 21 trials were performed for 4-0 and 5-0 Gore-Tex. The mean peak pressure at which fluid leakage was observed was 21 cm H2O for Nurolon and 34 cm H2O for Gore-Tex. Irrespective of suture choice, all trials were grouped by closure technique: running suture, locked continuous, and interrupted suture. No significant difference was noted between the groups. For each of the 3 trials groups by closure technique, running, locked continuous, and interrupted, Gore-Tex closures had a significantly higher peak pressure to failure. Interrupted Gore-Tex was significantly higher than Interrupted Nurolon (P=0.007), running Gore-Tex was significantly higher than running Nurolon (P=0.034), and locked Gore-Tex was significantly higher than locked Nurolon (P=0.014). Durotomy closure in the lumbar spine with Gore-Tex suture may be a reasonable option for providing a watertight closure. In this laboratory study, Gore-Tex suture provided watertight dural closures that withstood higher peak pressures.

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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

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

    International Nuclear Information System (INIS)

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


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

  6. Achondroplasia and multiple-suture craniosynostosis. (United States)

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


    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.

  7. Skin tension related to tension reduction sutures. (United States)

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


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

  8. Blepharoptosis correction with buried suture method. (United States)

    Park, Jang Woo; Kang, Moon Seok; Nam, Seung Min; Kim, Yong Bae


    Many surgical techniques have been developed to correct blepharoptosis, including the anterior levator resection or advancement, tarsoaponeurectomy, and Fasanella-Servat Müllerectomy. However, to minimize surgical scarring and reduce the postoperative recovery time, the procedure has been developed from a complete incision to a partial incision, which is appealing to patients. To aid the procedural development, this study describes a surgical technique in which the correction of blepharoptosis and a double eyelid fold operation are performed using a buried suture technique during the same operation. A retrospective review was conducted using the medical records and preoperative and postoperative photography of 121 patients who underwent simultaneous correction of blepharoptosis and had a double eyelid fold created between October 2010 and July 2011. All of the patients had mild (1-2 mm) or moderate (3-4 mm) bilateral blepharoptosis and excellent or good levator function (>8 mm). The average preoperative marginal reflex distance (MRD1) measured 1.174 (0.3) mm. No intraoperative complications occurred. The average postoperative MRD1 measured 3.968 (0.2) mm. There was statistical significance improvement between preoperative MRD1 and postoperative MRD1 (P<0.05). No symptomatic dry eye and exposure keratopathy were noted. Blepharoptosis correction using the buried suture technique is an effective technique for young patients experiencing mild to moderate blepharoptosis who want to have the double eyelid fold operation using the buried suture technique.

  9. Fiber from ramie plant (Boehmeria nivea): A novel suture biomaterial. (United States)

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


    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

  10. Phase manipulation of Goos–Hänchen shifts in a single-layer of graphene nanostructure under strong magnetic field (United States)

    Solookinejad, Gh; Jabbari, M.; Panahi, M.; Ahmadi Sangachin, E.


    In this paper, we discuss the phase management of Goos–Hänchen (GH) shifts of a probe light through a cavity with a single-layer graphene nanostructure under a strong magnetic field. By using the quantum mechanical density matrix formalism we study the GH shifts of reflected and transmitted light beams. It is realized that negative or positive GH shifts can be achieved simultaneously by tuning some controllable parameters such as relative phase and the Rabi frequency of the applied fields. Moreover, the thickness effect of the cavity structure is considered as an effective parameter for adjusting the GH shifts of reflected and transmitted light beams. We find that by choosing suitable parameters, a maximum negative shift of 4.5 mm and positive shift of 5.4 mm are possible for GH shifts in reflected and transmitted light. Our proposed model may be useful for developing all-optical devices in the infrared region.

  11. p-wave triggered superconductivity in single-layer graphene on an electron-doped oxide superconductor. (United States)

    Di Bernardo, A; Millo, O; Barbone, M; Alpern, H; Kalcheim, Y; Sassi, U; Ott, A K; De Fazio, D; Yoon, D; Amado, M; Ferrari, A C; Linder, J; Robinson, J W A


    Electron pairing in the vast majority of superconductors follows the Bardeen-Cooper-Schrieffer theory of superconductivity, which describes the condensation of electrons into pairs with antiparallel spins in a singlet state with an s-wave symmetry. Unconventional superconductivity was predicted in single-layer graphene (SLG), with the electrons pairing with a p-wave or chiral d-wave symmetry, depending on the position of the Fermi energy with respect to the Dirac point. By placing SLG on an electron-doped (non-chiral) d-wave superconductor and performing local scanning tunnelling microscopy and spectroscopy, here we show evidence for a p-wave triggered superconducting density of states in SLG. The realization of unconventional superconductivity in SLG offers an exciting new route for the development of p-wave superconductivity using two-dimensional materials with transition temperatures above 4.2 K.

  12. Controlling the formation of wrinkles in a single layer graphene sheet subjected to in-plane shear

    KAUST Repository

    Duan, Wen Hui


    The initiation and development of wrinkles in a single layer graphene sheet subjected to in-plane shear displacements are investigated. The dependence of the wavelength and amplitude of wrinkles on the applied shear displacements is explicitly obtained with molecular mechanics simulations. A continuum model is developed for the characteristics of the wrinkles which show that the wrinkle wavelength decreases with an increase in shear loading, while the amplitude of the wrinkles is found to initially increase and then become stable. The propagation and growth process of the wrinkles in the sheet is elucidated. It is expected that the research could promote applications of graphenes in the transportation of biological systems, separation science, and the development of the fluidic electronics. © 2011 Elsevier Ltd. All rights reserved.

  13. Phase transitions and optical properties of the semiconducting and metallic phases of single-layer MoS₂. (United States)

    Fair, K M; Ford, M J


    We report density functional theory calculations for single layer MoS2 in its 2H, semiconducting and 1T metallic phases in order to understand the relative stability of these two phases and transition between them in the presence of adsorbed lithium atoms and under compressive strain. We have determined the diffusion barriers between the two phases and demonstrate how the presence of Li adatoms or strain can significantly reduce these barriers. We show that the 2H and 1T structures have the same energy under 15% biaxial, compressive strain. This is the same strain value posited by Lin et al (2014 Nat. Nanotechnology 9 391-396) for their intermediate α phase. Calculations of the 1T and 2H permittivity and electron energy loss spectrum are also performed and characterized.

  14. 1617 nm emission control of an Er:YAG laser by a corrugated single-layer resonant grating mirror. (United States)

    Aubourg, Adrien; Rumpel, Martin; Didierjean, Julien; Aubry, Nicolas; Graf, Thomas; Balembois, François; Georges, Patrick; Ahmed, Marwan Abdou


    A resonant grating mirror (RGM) that combines a single layer planar waveguide and a subwavelength grating is used to simultaneously control the beam quality, the spectral bandwidth, and the polarization state of an Er:YAG laser. This simple device is compared to classical methods using several intracavity components: an etalon for wavelength selection, a thin film polarizer for polarization selection, and an aperture for spatial filtering. It is demonstrated that the RGM provides the same polarization purity, an enhanced spectral filtering, and a significant improvement of the beam quality. In CW operation, the Er:YAG laser with a RGM emits an output power of 1.4 W at 1617 nm with a M2 of 1.4.

  15. Highly balanced single-layer high-temperature superconductor SQUID gradiometer freely movable within the Earth's magnetic field

    International Nuclear Information System (INIS)

    Schultze, Volkmar; IJsselsteijn, Rob; May, Torsten; Meyer, Hans-Georg


    We developed a gradiometer system based on a single-layer high-temperature superconductor dc superconducting quantum interference device (SQUID), which can be freely moved within the Earth's magnetic field during measurement. The problem of circumferential shielding currents in the parallel gradiometer pick-up loop is solved by the use of an appropriately designed magnetometer SQUID integrated on the gradiometer chip. The magnetometer's feedback coil of the flux-locked loop is laid out as a small Helmholtz coil pair, thus keeping the homogeneous magnetic field constant for both the magnetometer and the gradiometer. Therefore, the balance of the directly coupled gradiometer SQUID is enhanced from 100 up to 3800. The noise limited magnetic field gradient resolution of 45 pT m -1 Hz -1/2 is preserved down to frequencies of several Hz even after strong motion in the Earth's magnetic field

  16. Analysis of current-driven oscillatory dynamics of single-layer homoepitaxial islands on crystalline conducting substrates (United States)

    Dasgupta, Dwaipayan; Kumar, Ashish; Maroudas, Dimitrios


    We report results of a systematic study on the complex oscillatory current-driven dynamics of single-layer homoepitaxial islands on crystalline substrate surfaces and the dependence of this driven dynamical behavior on important physical parameters, including island size, substrate surface orientation, and direction of externally applied electric field. The analysis is based on a nonlinear model of driven island edge morphological evolution that accounts for curvature-driven edge diffusion, edge electromigration, and edge diffusional anisotropy. Using a linear theory of island edge morphological stability, we calculate a critical island size at which the island's equilibrium edge shape becomes unstable, which sets a lower bound for the onset of time-periodic oscillatory dynamical response. Using direct dynamical simulations, we study the edge morphological dynamics of current-driven single-layer islands at larger-than-critical size, and determine the actual island size at which the migrating islands undergo a transition from steady to time-periodic asymptotic states through a subcritical Hopf bifurcation. At the highest symmetry of diffusional anisotropy examined, on {111} surfaces of face-centered cubic crystalline substrates, we find that more complex stable oscillatory states can be reached through period-doubling bifurcation at island sizes larger than those at the Hopf points. We characterize in detail the island morphology and dynamical response at the stable time-periodic asymptotic states, determine the range of stability of these oscillatory states terminated by island breakup, and explain the morphological features of the stable oscillating islands on the basis of linear stability theory.

  17. Bidirectional Barbed Sutures for Wound Closure: Evolution and Applications (United States)

    Paul, Malcolm D.


    Traditionally, wound closure sutures have in common the need to tie knots with the inherent risk of extrusion, palpability, microinfarcts, breakage, and slippage. Bidirectional barbed sutures have barbs arrayed in a helical fashion in opposing directions on either side of an unbarbed midsegment. This suture is inserted at the midpoint of a wound and pulled through till resistance is encountered from the opposing barbs; each half of the suture is then advanced to the lateral ends of the wound. This design provides a method of evenly distributing tension along the incision line, a faster suture placement and closure time with no need to tie knots, and the possibility of improved cosmesis. Bidirectional barbed sutures, which are available in both absorbable and nonabsorbable forms, can be used for simple closures, multilayered closures, and closure of high-tension wounds in a variety of surgical settings. PMID:24527114

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

    Directory of Open Access Journals (Sweden)

    Kamath B


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

  19. Automatic Detection of Wild-type Mouse Cranial Sutures

    DEFF Research Database (Denmark)

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

    , automatic detection of the cranial sutures becomes important. We have previously built a craniofacial, wild-type mouse atlas from a set of 10 Micro CT scans using a B-spline-based nonrigid registration method by Rueckert et al. Subsequently, all volumes were registered nonrigidly to the atlas. Using...... these transformations, any annotation on the atlas can automatically be transformed back to all cases. For this study, two rounds of tracing seven of the cranial sutures, were performed on the atlas by one observer. The average of the two rounds was automatically propagated to all the cases. For validation......, the observer traced the sutures on each of the mouse volumes as well. The observer outperforms the automatic approach by approximately 0.1 mm. All mice have similar errors while the suture error plots reveal that suture 1 and 2 are cumbersome, both for the observer and the automatic approach. These sutures can...

  20. Role of the osteoclast in cranial suture waveform patterning. (United States)

    Byron, Craig Daniel


    This study investigates the role of bone resorption in defining interdigitations characteristic of cranial suture waveform. Male mice from the CD-1 (ICR) background were analyzed at six age groups (n = 5 mice per group) in order to study the ontogenetic changes of osteoclast counts using tartrate-resistant acid phosphatase-stained histological sections of sagittal sutures. Additionally, the complexity of suture lines were measured ectocranially from the same age groups (n = 5 per group) using image capture and fractal geometry (ruler dimension method). The results suggest that osteoclast resorption is a contributor to suture patterning. Specifically, osteoclasts show the greatest activity along concave suture regions at 42 and 84 days (Kruskal-Wallis test statistic = 14.9; P weaning and the transition to a hard chow diet. These data demonstrate osteoclasts along the bone margin of the cranial suture and also indicate that sutures attain their complex shape at the same age when osteoclast number is highest along concave suture margins, underscoring the role of osteoclasts in generating the suture waveform pattern. 2006 Wiley-Liss, Inc.

  1. Sutural simplification in Physodoceratinae (Aspidoceratidae, Ammonitina

    Directory of Open Access Journals (Sweden)

    Checa, A.


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

  2. A Modified Fisherman's Knot for Laparoscopic Suturing. (United States)

    Meylemans, Diederik; Handojo, Karen; Devroe, Kurt; Aelvoet, Chris; Vermeiren, Koen; Tollens, Tim


    Suturing is an essential surgical technique, because there is no resection without the need for reconstruction. Therefore, every surgeon should master a set of suturing techniques so he can adapt his approach to the specificity of the situation. The development of laparoscopic surgery poses a new challenge as not all open techniques are amendable for laparoscopic use. We would like to propose a modified fisherman's knot, which has been optimised in our center for laparoscopic use. The technique can be used with every monofilament non-braided wire. The needle is placed through the tissue to be sutured and both wires are externalised through the trocar. First, a simple knot is placed by crossing the left over the right wire. Next, the left is turned around the right wire four times proximal to the starting knot and crossed to the left wire where an additional two turns are made moving away from the trocar. The knot is closed gently, making sure not to lock the knot. Then the instrument of Drouard is used to gently glide the knot over the right wire back through the trocar into the abdomen. After making sure that adequate pressure has been delivered to the knot, to firmly close the tissue, the wire must be cut at a length of at least 3 mm. A new wire should be used for every knot and in this manner several knots can be delivered to make sure the tissue is adequately closed. In our center, no known complications due to loosening or failure of these knots have occurred since we incorporated this knotting technique into our daily practice more than 20 years ago.

  3. Bone suture and lateral sinus lift surgery

    Directory of Open Access Journals (Sweden)

    Amin Rahpeyma


    Full Text Available Bone suture in lateral sinus lift has four indications. Three of them depend on creating a hole in the lateral maxillary sinus wall above the antrostomy window for securing the elevated medial maxillary sinus membrane to manage perforated Schneiderian membrane. Covering the buccal antrostomy window with the buccal fat pad (BFP for better nourishment of the inserted graft and as an alternative for bone tags in fixation of collagen membrane has been reported previously. A new indication for firmly anchoring the BFP to the medial maxillary sinus wall as the last resort for the management of perforated Schneiderian membrane is explained in this article.

  4. Evolution of Complexity in Paleozoic Ammonoid Sutures. (United States)

    Saunders; Work; Nikolaeva


    The septal sutures of 588 genera of Paleozoic ammonoids showed a 1600 percent increase in mean complexity over 140 million years. Within 475 ancestor/descendant pairs, descendants were more than twice as likely to be more complex than their ancestors. Twelve subclades (373 genera) averaged 34 percent increased complexity. These patterns are compatible with an active or driven system of long-term bias for increased complexity. Mass extinctions acted in opposition to this long-term trend, tending to eliminate more-complex forms and resetting the trend with each extinction event.

  5. Comparison of Arterial Repair through the Suture, Suture with Fibrin or Cyanoacrylate Adhesive in Ex-Vivo Porcine Aortic Segment

    Directory of Open Access Journals (Sweden)

    Marcus Vinicius H. de Carvalho

    Full Text Available Abstract Introduction: Tissue adhesives can be used as adjacent to sutures to drop or avoid bleeding in cardiovascular operations. Objective: To verify the efficiency of fibrin and cyanoacrylate adhesive to seal arterial sutures and if the adhesives penetrate through suture line to the inner of arteries. Methods: 20 abdominal aorta segments of pigs were divided into two groups according to the adhesive which would be used as adjacent to the suture. In every arterial segment an arteriotomy was done, followed by a conventional artery closure. Afterwards a colloidal fluid was injected inside the arterial segment with a simultaneous intravascular pressure monitoring up to a fluid leakage through the suture. This procedure was repeated after application of one of the adhesives on the suture in order to check if the bursting pressure increases. The inner aorta segments also were analyzed in order to check if there was intraluminal adhesive penetration. Results: In Suture 1 group, the mean arterial pressure sustained by the arterial suture reached 86±5.35 mmHg and after the fibrin adhesive application reached 104±11.96 (P<0.002. In the Suture 2 group, the mean arterial pressure sustained by the suture reached 83±2.67 mmHg and after the cyanoacrylate adhesive application reached 152±14.58 mmHg (P<0.002. Intraluminal adhesive penetration has not been noticed. Conclusion: There was a significant rise in the bursting pressure when tissue adhesives were used as adjacent to arterial suture, and this rise was higher if the cyanoacrylate adhesive was used. In addition, the adhesives do not penetrate through the suture line into the arteries.

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  7. Tensile strength and failure load of sutures for robotic surgery. (United States)

    Abiri, Ahmad; Paydar, Omeed; Tao, Anna; LaRocca, Megan; Liu, Kang; Genovese, Bradley; Candler, Robert; Grundfest, Warren S; Dutson, Erik P


    Robotic surgical platforms have seen increased use among minimally invasive gastrointestinal surgeons (von Fraunhofer et al. in J Biomed Mater Res 19(5):595-600, 1985. doi: 10.1002/jbm.820190511 ). However, these systems still suffer from lack of haptic feedback, which results in exertion of excessive force, often leading to suture failures (Barbash et al. in Ann Surg 259(1):1-6, 2014. doi: 10.1097/SLA.0b013e3182a5c8b8 ). This work catalogs tensile strength and failure load among commonly used sutures in an effort to prevent robotic surgical consoles from exceeding identified thresholds. Trials were thus conducted on common sutures varying in material type, gauge size, rate of pulling force, and method of applied force. Polydioxanone, Silk, Vicryl, and Prolene, gauges 5-0 to 1-0, were pulled till failure using a commercial mechanical testing system. 2-0 and 3-0 sutures were further tested for the effect of pull rate on failure load at rates of 50, 200, and 400 mm/min. 3-0 sutures were also pulled till failure using a da Vinci robotic surgical system in unlooped, looped, and at the needle body arrangements. Generally, Vicryl and PDS sutures had the highest mechanical strength (47-179 kN/cm 2 ), while Silk had the lowest (40-106 kN/cm 2 ). Larger diameter sutures withstand higher total force, but finer gauges consistently show higher force per unit area. The difference between material types becomes increasingly significant as the diameters decrease. Comparisons of identical suture materials and gauges show 27-50% improvement in the tensile strength over data obtained in 1985 (Ballantyne in Surg Endosc Other Interv Tech 16(10):1389-1402, 2002. doi: 10.1007/s00464-001-8283-7 ). No significant differences were observed when sutures were pulled at different rates. Reduction in suture strength appeared to be strongly affected by the technique used to manipulate the suture. Availability of suture tensile strength and failure load data will help define software safety

  8. Geophysical exploration of the Kalahari Suture Zone (United States)

    Brett, J. S.; Mason, R.; Smith, P. H.


    Fancamp Resources Limited of Montreal, Canada, commenced exploration of the Kalahari Suture Zone in southwest Botswana in 1996, following the interpretation of airborne magnetic surveys covering 400 km of strike along the Kalahari Suture Zone. Initial focus was on mafic/ultramafic intrusions associated with the Tshane Complex as potential targets for CuNiPGM mineralization, but these targets are now considered to be too deeply buried (> 700 m) to be of economic significance at this time. The exploration focus has been redirected to several prospective large coincident magnetic/gravity anomalies. These are considered prospective targets for Olympic Dam-type CuCo mineralisation associated with alkaline intrusive complexes, and/or NiCuCoPGM mineralisation associated with basic intrusive complexes. The two most important and prospective targets are the so-called 'Great Red Spot' and Tsetseng Complex. Additional ground geophysical surveys and deep drilling are planned for the next phase of exploration. These large targets are of high priority and represent tremendous potential for mineral development in the sparsely populated area of western Botswana.

  9. Single layers and multilayers of GaN and AlN in square-octagon structure: Stability, electronic properties, and functionalization (United States)

    Gürbüz, E.; Cahangirov, S.; Durgun, E.; Ciraci, S.


    Further to planar single-layer hexagonal structures, GaN and AlN can also form free-standing, single-layer structures constructed from squares and octagons. We performed an extensive analysis of dynamical and thermal stability of these structures in terms of ab initio finite-temperature molecular dynamics and phonon calculations together with the analysis of Raman and infrared active modes. These single-layer square-octagon structures of GaN and AlN display directional mechanical properties and have wide, indirect fundamental band gaps, which are smaller than their hexagonal counterparts. These density functional theory band gaps, however, increase and become wider upon correction. Under uniaxial and biaxial tensile strain, the fundamental band gaps decrease and can be closed. The electronic and magnetic properties of these single-layer structures can be modified by adsorption of various adatoms, or by creating neutral cation-anion vacancies. The single-layer structures attain magnetic moment by selected adatoms and neutral vacancies. In particular, localized gap states are strongly dependent on the type of vacancy. The energetics, binding, and resulting electronic structure of bilayer, trilayer, and three-dimensional (3D) layered structures constructed by stacking the single layers are affected by vertical chemical bonds between adjacent layers. In addition to van der Waals interaction, these weak vertical bonds induce buckling in planar geometry and enhance their binding, leading to the formation of stable 3D layered structures. In this respect, these multilayers are intermediate between van der Waals solids and wurtzite crystals, offering a wide range of tunability.

  10. Frequency of Dehiscence in Hand-Sutured and Stapled Intestinal Anastomoses in Dogs. (United States)

    Duell, Jason R; Thieman Mankin, Kelley M; Rochat, Mark C; Regier, Penny J; Singh, Ameet; Luther, Jill K; Mison, Michael B; Leeman, Jessica J; Budke, Christine M


    To determine the frequency of dehiscence of hand-sutured and stapled intestinal anastomoses in the dog and compare the surgery duration for the methods of anastomosis. Historical cohort study. Two hundred fourteen client-owned dogs undergoing hand-sutured (n = 142) or stapled (n = 72) intestinal anastomoses. Medical records from 5 referral institutions were searched for dogs undergoing intestinal resection and anastomosis between March 2006 and February 2014. Demographic data, presence of septic peritonitis before surgery, surgical technique (hand-sutured or stapled), surgery duration, surgeon (resident versus faculty member), indication for surgical intervention, anatomic location of resection and anastomosis, and if dehiscence was noted postoperatively were retrieved. Estimated frequencies were summarized and presented as proportions and 95% confidence intervals (CI) and continuous outcomes as mean (95% CI). Comparisons were made across methods of anastomosis. Overall, 29/205 dogs (0.14, 95% CI 0.10-00.19) had dehiscence, including 21/134 dogs (0.16, 0.11-0.23) undergoing hand-sutured anastomosis and 8/71 dogs (0.11, 0.06-0.21) undergoing stapled anastomosis. There was no significant difference in the frequency of dehiscence across anastomosis methods (χ(2), P = .389). The mean (95% CI) surgery duration of 140 minutes (132-147) for hand- sutured anastomoses and 108 minutes (99-119) for stapled anastomoses was significantly different (t-test, P dogs but surgery duration is significantly reduced by the use of staples for intestinal closure. © Copyright 2015 by The American College of Veterinary Surgeons.

  11. The malament suture: any role in transvesical prostatectomy ...

    African Journals Online (AJOL)

    Conclusion: From our study, the Malament suture does not increase the incidence of bladder neck stenosis; neither does it reduce the need for blood transfusion. Prospective studies are required to further investigate these and find out if the Malament suture reduces the volume of fluid required for irrigation or the need to ...

  12. Mechanical model of suture joints with fibrous connective layer (United States)

    Miroshnichenko, Kateryna; Liu, Lei; Tsukrov, Igor; Li, Yaning


    A composite model for suture joints with a connective layer of aligned fibers embedded in soft matrix is proposed. Based on the principle of complementary virtual work, composite cylinder assemblage (CCA) approach and generalized self-consistent micro-mechanical models, a hierarchical homogenization methodology is developed to systematically quantify the synergistic effects of suture morphology and fiber orientation on the overall mechanical properties of sutures. Suture joints with regular triangular wave-form serve as an example material system to apply this methodology. Both theoretical and finite element mechanical models are developed and compared to evaluate the overall normal stiffness of sutures as a function of wavy morphology of sutures, fiber orientation, fiber volume fraction, and the mechanical properties of fibers and matrix in the interfacial layer. It is found that generally due to the anisotropy-induced coupling effects between tensile and shear deformation, the effective normal stiffness of sutures is highly dependent on the fiber orientation in the connective layer. Also, the effective shear modulus of the connective layer and the stiffness ratio between the fiber and matrix significantly influence the effects of fiber orientation. In addition, optimal fiber orientations are found to maximize the stiffness of suture joints.

  13. Punctal occlusion with Prolene suture material in the patients with ...

    African Journals Online (AJOL)

    Aim: To analyze the efficacy and outcomes of punctal occlusion with 5-0 Prolene suture material for the treatment of dry eye. Materials and. Methods: A total of 20 patients with moderate and severe dry eyes, recalcitrant to maximal medical therapy, underwent temporary punctal occlusion with 5-0 Prolene suture material.

  14. Suture associated corneal abscess three years after cataract surgery ...

    African Journals Online (AJOL)

    We describe a case of corneal abscess presenting three years after uneventful cataract extraction with posterior chamber lens implantation through a limbal incision secured with threesutures placed in the clear cornea. After removing the abscess, a loose10/0 nylon suture was found at the base of an ulcer. The suture was ...

  15. Suture associated corneal abscess three years after cataract surgery ...

    African Journals Online (AJOL)

    The abscess was carefully removed on slit lamp using blunt tipped forceps without breaking the thin membrane covering it. There was a deep corneal depression at the bottom of which was found a loose 10/0 nylon corneoscleral suture. Another loose suture was present at the 12 o'clock position surrounded by stromal ...

  16. Density functional theory study of chemical sensing on surfaces of single-layer MoS2 and graphene

    International Nuclear Information System (INIS)

    Mehmood, F.; Pachter, R.


    In this work, density functional theory (DFT) calculations have been used to investigate chemical sensing on surfaces of single-layer MoS 2 and graphene, considering the adsorption of the chemical compounds triethylamine, acetone, tetrahydrofuran, methanol, 2,4,6-trinitrotoluene, o-nitrotoluene, o-dichlorobenzene, and 1,5-dicholoropentane. Physisorption of the adsorbates on free-standing surfaces was analyzed in detail for optimized material structures, considering various possible adsorption sites. Similar adsorption characteristics for the two surface types were demonstrated, where inclusion of a correction to the DFT functional for London dispersion was shown to be important to capture interactions at the interface of molecular adsorbate and surface. Charge transfer analyses for adsorbed free-standing surfaces generally demonstrated very small effects. However, charge transfer upon inclusion of the underlying SiO 2 substrate rationalized experimental observations for some of the adsorbates considered. A larger intrinsic response for the electron-donor triethylamine adsorbed on MoS 2 as compared to graphene was demonstrated, which may assist in devising chemical sensors for improved sensitivity

  17. Electronic evidence of an insulator-superconductor crossover in single-layer FeSe/SrTiO3 films. (United States)

    He, Junfeng; Liu, Xu; Zhang, Wenhao; Zhao, Lin; Liu, Defa; He, Shaolong; Mou, Daixiang; Li, Fangsen; Tang, Chenjia; Li, Zhi; Wang, Lili; Peng, Yingying; Liu, Yan; Chen, Chaoyu; Yu, Li; Liu, Guodong; Dong, Xiaoli; Zhang, Jun; Chen, Chuangtian; Xu, Zuyan; Chen, Xi; Ma, Xucun; Xue, Qikun; Zhou, X J


    In high-temperature cuprate superconductors, it is now generally agreed that superconductivity is realized by doping an antiferromagnetic Mott (charge transfer) insulator. The doping-induced insulator-to-superconductor transition has been widely observed in cuprates, which provides important information for understanding the superconductivity mechanism. In the iron-based superconductors, however, the parent compound is mostly antiferromagnetic bad metal, raising a debate on whether an appropriate starting point should go with an itinerant picture or a localized picture. No evidence of doping-induced insulator-superconductor transition (or crossover) has been reported in the iron-based compounds so far. Here, we report an electronic evidence of an insulator-superconductor crossover observed in the single-layer FeSe film grown on a SrTiO3 substrate. By taking angle-resolved photoemission measurements on the electronic structure and energy gap, we have identified a clear evolution of an insulator to a superconductor with increasing carrier concentration. In particular, the insulator-superconductor crossover in FeSe/SrTiO3 film exhibits similar behaviors to that observed in the cuprate superconductors. Our results suggest that the observed insulator-superconductor crossover may be associated with the two-dimensionality that enhances electron localization or correlation. The reduced dimensionality and the interfacial effect provide a new pathway in searching for new phenomena and novel superconductors with a high transition temperature.

  18. Electronic evidence of an insulator–superconductor crossover in single-layer FeSe/SrTiO3 films (United States)

    He, Junfeng; Liu, Xu; Zhang, Wenhao; Zhao, Lin; Liu, Defa; He, Shaolong; Mou, Daixiang; Li, Fangsen; Tang, Chenjia; Li, Zhi; Wang, Lili; Peng, Yingying; Liu, Yan; Chen, Chaoyu; Yu, Li; Liu, Guodong; Dong, Xiaoli; Zhang, Jun; Chen, Chuangtian; Xu, Zuyan; Chen, Xi; Ma, Xucun; Xue, Qikun; Zhou, X. J.


    In high-temperature cuprate superconductors, it is now generally agreed that superconductivity is realized by doping an antiferromagnetic Mott (charge transfer) insulator. The doping-induced insulator-to-superconductor transition has been widely observed in cuprates, which provides important information for understanding the superconductivity mechanism. In the iron-based superconductors, however, the parent compound is mostly antiferromagnetic bad metal, raising a debate on whether an appropriate starting point should go with an itinerant picture or a localized picture. No evidence of doping-induced insulator–superconductor transition (or crossover) has been reported in the iron-based compounds so far. Here, we report an electronic evidence of an insulator–superconductor crossover observed in the single-layer FeSe film grown on a SrTiO3 substrate. By taking angle-resolved photoemission measurements on the electronic structure and energy gap, we have identified a clear evolution of an insulator to a superconductor with increasing carrier concentration. In particular, the insulator–superconductor crossover in FeSe/SrTiO3 film exhibits similar behaviors to that observed in the cuprate superconductors. Our results suggest that the observed insulator–superconductor crossover may be associated with the two-dimensionality that enhances electron localization or correlation. The reduced dimensionality and the interfacial effect provide a new pathway in searching for new phenomena and novel superconductors with a high transition temperature. PMID:25502774

  19. High performance of low band gap polymer-based ambipolar transistor using single-layer graphene electrodes. (United States)

    Choi, Jong Yong; Kang, Woonggi; Kang, Boseok; Cha, Wonsuk; Son, Seon Kyoung; Yoon, Youngwoon; Kim, Hyunjung; Kang, Youngjong; Ko, Min Jae; Son, Hae Jung; Cho, Kilwon; Cho, Jeong Ho; Kim, BongSoo


    Bottom-contact bottom-gate organic field-effect transistors (OFETs) are fabricated using a low band gap pDTTDPP-DT polymer as a channel material and single-layer graphene (SLG) or Au source/drain electrodes. The SLG-based ambipolar OFETs significantly outperform the Au-based ambipolar OFETs, and thermal annealing effectively improves the carrier mobilities of the pDTTDPP-DT films. The difference is attributed to the following facts: (i) the thermally annealed pDTTDPP-DT chains on the SLG assume more crystalline features with an edge-on orientation as compared to the polymer chains on the Au, (ii) the morphological features of the thermally annealed pDTTDPP-DT films on the SLG electrodes are closer to the features of those on the gate dielectric layer, and (iii) the SLG electrode provides a flatter, more hydrophobic surface that is favorable for the polymer crystallization than the Au. In addition, the preferred carrier transport in each electrode-based OFET is associated with the HOMO/LUMO alignment relative to the Fermi level of the employed electrode. All of these experimental results consistently explain why the carrier mobilities of the SLG-based OFET are more than 10 times higher than those of the Au-based OTFT. This work demonstrates the strong dependence of ambipolar carrier transport on the source/drain electrode and annealing temperature.

  20. Single-layer 2nd-order high-T{sub c} SQUID gradiometer for use in unshielded environments

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Soon-Gul; Park, Seung Moon; Kang, Chan Seok [Korea University, Chungnam (Korea, Republic of); Kim, In-Seon [Korea Research Institute of Standards and Science, Daejon (Korea, Republic of); Kim, Sang-Jae [Cheju National University, Cheju (Korea, Republic of)


    We have studied the fabrication of second-order SQUID gradiometers from single-layer high-T{sub c} film and the feasibility of using those gradiometers in magnetocardiography. The gradiometer contains three parallel-connected pickup loops that are directly coupled to a step-edge junction SQUID with the coupling polarity of the center loop opposite to those of the two side loops. For a well-balanced gradiometer with a balancing factor of 10{sup 3}, we achieved an unshielded gradient noise of 0.84 pT/cm{sup 2}/Hz{sup 1/2} at 1 Hz, which corresponds to an equivalent field noise of 280 fT/Hz{sup 1/2}. A gradiometer with a 5.8-mm baseline successfully recorded the magnetocardic signals of a human subject, demonstrating the feasibility of using the device in biomagnetism. We have also studied the use of submicron YBCO bridges as Josephson elements of long-baseline gradiometers. The bridges were fabricated from 3-{mu}m-wide, 300-nm-thick YBCO lines with a thin layer of Au on top by using a focused-ion-beam (FIB) patterning method. The temperature-dependent critical currents, I{sub c}(T), and the normal state resistances, R{sub N}(T), showed SIS-type behaviors, which are believed to be due to naturally formed grain boundaries.

  1. Dual functional porous anti-reflective coatings with a photocatalytic effect based on a single layer system (United States)

    Jilavi, M. H.; Mousavi, S. H.; Müller, T. S.; de Oliveira, P. W.


    Anti-reflection and photocatalytic properties are desirable for improving the optical properties of electronic devices. We describe a method of fabrication a single-layer, anti-reflective (AR) thin film with an additional photocatalytic property. The layer is deposited on glass substrates by means of a low-cost dip-coating method using a SiO2-TiO2 solution. A comparative study was undertaken to investigate the effects of TiO2 concentrations on the photocatalytic properties of the film and to determine the optimal balance between transmittance and photocatalysis. The average transmittance increases from T = 90.51% to T = 95.46 ± 0.07% for the wavelengths between 380 and 1200 nm. The structural characterization indicated the formation of thin, porous SiO2-TiO2 films with a roughness of less than 7.5 nm. The quality of the samples was evaluated by a complete test program of the mechanical, chemical and accelerated weathering stability. This results open up new possibilities for cost-effective AR coatings for the glass and solar cell industries.

  2. Development and characterization of light-emitting diodes (LEDs) based on ruthenium complex single layer for transparent displays

    Energy Technology Data Exchange (ETDEWEB)

    Santos, G.; Fonseca, F.; Andrade, A.M. [Laboratorio de Microelectronica, Departamento de Engenharia de Sistemas Electronicos, Escola Politecnica da Universidade de Sao Paulo (Brazil); Patrocinio, A.O.T.; Mizoguchi, S.K.; Murakami Iha, N.Y. [Laboratorio de Fotoquimica Inorganica e Conversao de Energia, Instituto de Quimica da Universidade de Sao Paulo (Brazil); Peres, M.; Monteiro, T.; Pereira, L. [Departamento de Fisica e I3N, Universidade de Aveiro (Portugal)


    In this work, two ruthenium complexes,[Ru(bpy){sub 3}](PF{sub 6}){sub 2} and[Ru(ph2phen){sub 3}](PF{sub 6}){sub 2} in poly(methylmethacrylate) matrix were employed to build single-layer light-emitting electrochemical cells by spin coating on indium tin oxide substrate. In both cases the electroluminescence spectra exhibit a relatively broad band with maxima near to 625 nm and CIE (x,y) color coordinates of (0.64,0.36), which are comparable with the photoluminescence data in the same medium. The best result was obtained with the[Ru(bpy){sub 3}](PF{sub 6}){sub 2} device where the optical output power approaches 10{mu}W at the band maximum with a wall-plug efficiency higher than 0.03%. The lowest driving voltage is about 4 V for an electrical current of 20 mA. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Room-temperature superparamagnetism due to giant magnetic anisotropy in Mo S defected single-layer MoS2 (United States)

    Khan, M. A.; Leuenberger, Michael N.


    Room-temperature superparamagnetism due to a large magnetic anisotropy energy (MAE) of a single atom magnet has always been a prerequisite for nanoscale magnetic devices. Realization of two dimensional (2D) materials such as single-layer (SL) MoS2, has provided new platforms for exploring magnetic effects, which is important for both fundamental research and for industrial applications. Here, we use density functional theory (DFT) to show that the antisite defect (Mo S ) in SL MoS2 is magnetic in nature with a magnetic moment μ of  ∼2 μB and, remarkably, exhibits an exceptionally large atomic scale MAE =\\varepsilon\\parallel-\\varepsilon\\perp of  ∼500 meV. Our calculations reveal that this giant anisotropy is the joint effect of strong crystal field and significant spin–orbit coupling (SOC). In addition, the magnetic moment μ can be tuned between 1 μB and 3 μB by varying the Fermi energy \\varepsilonF , which can be achieved either by changing the gate voltage or by chemical doping. We also show that MAE can be raised to  ∼1 eV with n-type doping of the MoS2:Mo S sample. Our systematic investigations deepen our understanding of spin-related phenomena in SL MoS2 and could provide a route to nanoscale spintronic devices.

  4. Single-layer centrifugation separates spermatozoa from diploid cells in epididymal samples from gray wolves, Canis lupus (L.). (United States)

    Muñoz-Fuentes, Violeta; Linde Forsberg, Catharina; Vilà, Carles; Morrell, Jane M


    Sperm samples may be used for assisted reproductive technologies (e.g., farmed or endangered species) or as a source of haploid DNA or sperm-specific RNA. When ejaculated spermatozoa are not available or are very difficult to obtain, as is the case for most wild endangered species, the epididymides of dead animals (e.g., animals that have been found dead, shot by hunters or poachers, or that that require euthanasia in zoological collections) can be used as a source of sperm. Such epididymal sperm samples are usually contaminated with cellular debris, erythrocytes, leukocytes, and sometimes also bacteria. These contaminants may be sources of reactive oxygen species that damage spermatozoa during freezing or contribute undesired genetic material from diploid cells. We used single-layer centrifugation through a colloid formulation, Androcoll-C, to successfully separate wolf epididymal spermatozoa from contaminating cells and cellular debris in epididymal samples harvested from carcasses. Such a procedure may potentially be applied to epididymal sperm samples from other species. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Planar heterostructures of single-layer transition metal dichalcogenides: Composite structures, Schottky junctions, tunneling barriers, and half metals (United States)

    Aras, Mehmet; Kılıç, ćetin; Ciraci, S.


    Planar composite structures formed from the stripes of transition metal dichalcogenides joined commensurately along their zigzag or armchair edges can attain different states in a two-dimensional (2D), single-layer, such as a half metal, 2D or one-dimensional (1D) nonmagnetic metal and semiconductor. Widening of stripes induces metal-insulator transition through the confinements of electronic states to adjacent stripes, that results in the metal-semiconductor junction with a well-defined band lineup. Linear bending of the band edges of the semiconductor to form a Schottky barrier at the boundary between the metal and semiconductor is revealed. Unexpectedly, strictly 1D metallic states develop in a 2D system along the boundaries between stripes, which pins the Fermi level. Through the δ doping of a narrow metallic stripe one attains a nanowire in the 2D semiconducting sheet or narrow band semiconductor. A diverse combination of constituent stripes in either periodically repeating or finite-size heterostructures can acquire critical fundamental features and offer device capacities, such as Schottky junctions, nanocapacitors, resonant tunneling double barriers, and spin valves. These predictions are obtained from first-principles calculations performed in the framework of density functional theory.

  6. Single-layer ionic conduction on carboxyl-terminated silane monolayers patterned by constructive lithography. (United States)

    Berson, Jonathan; Burshtain, Doron; Zeira, Assaf; Yoffe, Alexander; Maoz, Rivka; Sagiv, Jacob


    Ionic transport plays a central role in key technologies relevant to energy, and information processing and storage, as well as in the implementation of biological functions in living organisms. Here, we introduce a supramolecular strategy based on the non-destructive chemical patterning of a highly ordered self-assembled monolayer that allows the reproducible fabrication of ion-conducting surface patterns (ion-conducting channels) with top -COOH functional groups precisely definable over the full range of length scales from nanometre to centimetre. The transport of a single layer of selected metal ions and the electrochemical processes related to their motion may thus be confined to predefined surface paths. As a generic solid ionic conductor that can accommodate different mobile ions in the absence of any added electrolyte, these ion-conducting channels exhibit bias-induced competitive transport of different ionic species. This approach offers unprecedented opportunities for the realization of designed ion-conducting systems with nanoscale control, beyond the inherent limitations posed by available ionic materials.

  7. Efficient Nitrogen Doping of Single-Layer Graphene Accompanied by Negligible Defect Generation for Integration into Hybrid Semiconductor Heterostructures. (United States)

    Sarau, George; Heilmann, Martin; Bashouti, Muhammad; Latzel, Michael; Tessarek, Christian; Christiansen, Silke


    While doping enables application-specific tailoring of graphene properties, it can also produce high defect densities that degrade the beneficial features. In this work, we report efficient nitrogen doping of ∼11 atom % without virtually inducing new structural defects in the initial, large-area, low defect, and transferred single-layer graphene. To shed light on this remarkable high-doping-low-disorder relationship, a unique experimental strategy consisting of analyzing the changes in doping, strain, and defect density after each important step during the doping procedure was employed. Complementary micro-Raman mapping, X-ray photoelectron spectroscopy, and optical microscopy revealed that effective cleaning of the graphene surface assists efficient nitrogen incorporation accompanied by mild compressive strain resulting in negligible defect formation in the doped graphene lattice. These original results are achieved by separating the growth of graphene from its doping. Moreover, the high doping level occurred simultaneously with the epitaxial growth of n-GaN micro- and nanorods on top of graphene, leading to the flow of higher currents through the graphene/n-GaN rod interface. Our approach can be extended toward integrating graphene into other technologically relevant hybrid semiconductor heterostructures and obtaining an ohmic contact at their interfaces by adjusting the doping level in graphene.

  8. Study of the mechanical properties of single- layer and multi-layer metallic coatings with protective-decorative applications

    Directory of Open Access Journals (Sweden)

    Cherneva Sabina


    Full Text Available Single thin coating of matt nickel (Nimat, a mirror bright copper (Cubright, a mirror bright nickel (Nibright and their combinations were electrochemically deposited on brass substrate with thickness 500 μm. The basic aim was electrodeposition of two-layer Cubright/Nimat and Nibright/Cubright systems, and three-layer Nibright Cubrigh/Nimat system, which are among the most widely applied protective and decorative systems in light and medium operating conditions of corrosion. The thicknesses of the obtained films varied from 1 μm to 3.25 μm. They were investigated via nanoindentation experiments, in order to characterize their basic physical and mechanical characteristics, related with their good adhesion and corrosion protective ability, as well as ensuring the integrity of the system “protective coating/substrate” to possible mechanical, dynamic and/or thermal stresses. As a result, load-displacement curves were obtained and indentation hardness and indentation modulus were calculated using the Oliver & Pharr approximation method. The dependence of the indentation modulus and the indentation hardness on the depth of the indentation, surface morphology and structure of the obtained coatings, their texture and surface roughness were investigated too. The obtained results showed that the three-layer Nibright/Cubright /Niimat/CuZn37 system has highest indentation modulus and indentation hardness, following by two-layer Nibright/Cubright system and single layer coatings.

  9. Junctionless Diode Enabled by Self-Bias Effect of Ion Gel in Single-Layer MoS2 Device. (United States)

    Khan, Muhammad Atif; Rathi, Servin; Park, Jinwoo; Lim, Dongsuk; Lee, Yoontae; Yun, Sun Jin; Youn, Doo-Hyeb; Kim, Gil-Ho


    The self-biasing effects of ion gel from source and drain electrodes on electrical characteristics of single layer and few layer molybdenum disulfide (MoS 2 ) field-effect transistor (FET) have been studied. The self-biasing effect of ion gel is tested for two different configurations, covered and open, where ion gel is in contact with either one or both, source and drain electrodes, respectively. In open configuration, the linear output characteristics of the pristine device becomes nonlinear and on-off ratio drops by 3 orders of magnitude due to the increase in "off" current for both single and few layer MoS 2 FETs. However, the covered configuration results in a highly asymmetric output characteristics with a rectification of around 10 3 and an ideality factor of 1.9. This diode like behavior has been attributed to the reduction of Schottky barrier width by the electric field of self-biased ion gel, which enables an efficient injection of electrons by tunneling at metal-MoS 2 interface. Finally, finite element method based simulations are carried out and the simulated results matches well in principle with the experimental analysis. These self-biased diodes can perform a crucial role in the development of high-frequency optoelectronic and valleytronic devices.

  10. Single-layer 2nd-order high-Tc SQUID gradiometer for use in unshielded environments

    International Nuclear Information System (INIS)

    Lee, Soon-Gul; Park, Seung Moon; Kang, Chan Seok; Kim, In-Seon; Kim, Sang-Jae


    We have studied the fabrication of second-order SQUID gradiometers from single-layer high-T c film and the feasibility of using those gradiometers in magnetocardiography. The gradiometer contains three parallel-connected pickup loops that are directly coupled to a step-edge junction SQUID with the coupling polarity of the center loop opposite to those of the two side loops. For a well-balanced gradiometer with a balancing factor of 10 3 , we achieved an unshielded gradient noise of 0.84 pT/cm 2 /Hz 1/2 at 1 Hz, which corresponds to an equivalent field noise of 280 fT/Hz 1/2 . A gradiometer with a 5.8-mm baseline successfully recorded the magnetocardic signals of a human subject, demonstrating the feasibility of using the device in biomagnetism. We have also studied the use of submicron YBCO bridges as Josephson elements of long-baseline gradiometers. The bridges were fabricated from 3-μm-wide, 300-nm-thick YBCO lines with a thin layer of Au on top by using a focused-ion-beam (FIB) patterning method. The temperature-dependent critical currents, I c (T), and the normal state resistances, R N (T), showed SIS-type behaviors, which are believed to be due to naturally formed grain boundaries.

  11. Colloid single-layer centrifugation improves post-thaw donkey (Equus asinus) sperm quality and is related to ejaculate freezability. (United States)

    Ortiz, I; Dorado, J; Acha, D; Gálvez, M J; Urbano, M; Hidalgo, M


    The aim of this study was to determine whether colloid single-layer centrifugation (SLC) improves post-thaw donkey sperm quality and if this potential enhancement is related to ejaculate freezability. Semen from Andalusian donkeys was frozen following a standard protocol. SLC was performed on frozen-thawed semen and post-thaw sperm parameters were compared with uncentrifuged samples. Sperm quality was estimated by integrating in a single value sperm motility (assessed by computer-assisted sperm analysis), morphology and viability (evaluated under brightfield or fluorescence microscopy). Sperm freezability was calculated as the relationship between sperm quality obtained before freezing and after thawing. Ejaculates were classified into low, medium and high freezability groups using the 25th and 75th percentiles as thresholds. All sperm parameters were significantly (P<0.01) higher in SLC-selected samples in comparison to uncentrifuged frozen-thawed semen and several kinematic parameters were even higher than those obtained in fresh semen. The increment of sperm parameters after SLC selection was correlated with ejaculate freezability, obtaining the highest values after SLC in semen samples with low freezability. We concluded that, based on the sperm-quality parameters evaluated, SLC can be a suitable procedure to improve post-thaw sperm quality of cryopreserved donkey semen, in particular for those ejaculates with low freezability.

  12. A randomized trial comparing skin closure in cesarean section: interrupted suture with nylon vs subcuticular suture with No '1' polyfilament. (United States)

    Shrestha, A; Napit, J; Neupane, B; Sedhai, L B


    Cesarean section is one of the most commonly performed operations in most countries of the world including Nepal. Hence there is a load on the financial resources of healthcare system. The rational of this study was to utilize the remaining No '1' polyfilament after closing rectus sheath to stitch skin. So, the primary objective was to determine the wound complication rates for subcuticular suture with No'1' petcryl (polyfilamentpolyglycolic acid) Vs intermittent suture with nylon 2-0 for skin closure at cesarean delivery and secondary objective was to compare postoperative pain and patient satisfaction about the scar. One hundred and thirty eight women undergoing cesarean section at Chitwan Medical College was randomized to either intermittent skin suture with nylon 2-0 or subcuticular with polyfilament No '1' (remaining suture after closing rectus sheath). Evidence of wound infection, pain and overall satisfaction were assessed postoperatively. The overall wound complications rate in subcuticular stitch with No'1' polyfilament suture were similar as in intermittent mattress stitch with nylon 2-0 (15.9% vs. 14.49%). Pain on postoperative third day and six weeks and overall satisfaction about wound were similar in both groups. Only prolong rupture of membrane >18 hours was found to be a significant risk factor of wound infection (OR: 3.4; p=0.04). The remaining no '1' polyfilament suture (petcryl) after suturing rectus sheath can be safely used to close skin suture in cesarean section.

  13. Single layers of WS2 nanoplates embedded in nitrogen-doped carbon nanofibers as anode materials for lithium-ion batteries (United States)

    Yu, Sunmoon; Jung, Ji-Won; Kim, Il-Doo


    Single layers of WS2 nanoplates are uniformly embedded in nitrogen-doped carbon nanofibers (WS2@NCNFs) via a facile electrospinning method. Crystallization of the single-layered WS2 nanoplates and in situ nitrogen doping into the carbon nanofibers were simultaneously accomplished during a two-step heat treatment. The distinctive structure of the WS2@NCNFs enables outstanding electrochemical performances.Single layers of WS2 nanoplates are uniformly embedded in nitrogen-doped carbon nanofibers (WS2@NCNFs) via a facile electrospinning method. Crystallization of the single-layered WS2 nanoplates and in situ nitrogen doping into the carbon nanofibers were simultaneously accomplished during a two-step heat treatment. The distinctive structure of the WS2@NCNFs enables outstanding electrochemical performances. Electronic supplementary information (ESI) available: Experimental section, SEM images of WS2 powder and ground WS2 powder, TEM image and SAED pattern of the WS2 powder, Raman spectra of the WS2 powder, CV curves of the WS2 powder, voltage profiles of the WS2 powder, schematic diagram of WS2@NCNFs undergoing lithium storage reactions, electrochemical performance of NCNFs, morphologies and EDS mapping of WS2@NCNFs after cycling, and a table of contributions of NCNFs to the specific capacity. See DOI: 10.1039/c5nr02425k

  14. Effect of non-sperm cells removal with single-layer colloidal centrifugation on myeloperoxidase concentration in post-thaw equine semen. (United States)

    Ponthier, Jérôme; Teague, Sheila R; Franck, Thierry Y; de la Rebière, Geoffroy; Serteyn, Didier D; Brinsko, Steven P; Love, Charles C; Blanchard, Terry L; Varner, Dickson D; Deleuze, Stéfan C


    Myeloperoxidase (MPO) is a pro-oxidant enzyme contained in and released by neutrophils during degranulation or after lysis. Post-thaw semen contains MPO and its concentration is associated with decreased sperm motility. Recently, MPO concentration in post-thaw semen was shown to be associated with the presence of non-sperm cells (NSC). The objective of this study was to evaluate the effect of a single-layer colloidal centrifugation before cryopreservation on NSC and MPO concentrations in equine semen. The experimental design consisted of freezing semen with or without previous centrifugation through two concentrations of single-layer colloid media. Non-sperm cells and MPO concentrations were assessed in pellet and upper layer at each step of the procedure and MPO was detected in cells by immunocytochemistry. Single-layer colloid centrifugation decreased NSC and MPO concentrations in post-thaw semen. The MPO concentration was correlated with concentration of NSC in the upper layer of the supernatant. In post-thaw semen, with or without previous single-layer colloid centrifugation, MPO concentration was correlated with concentration of NSC. Overall, neutrophils were rarely observed and NSC were mainly epithelial cells or cellular debris, as demonstrated by MPO immunocytochemistry. At all steps of the semen processing and cryopreservation, MPO immunostaining was clearly identified only on NSC. In conclusion, our study shows that NSC present in fresh semen release MPO during freezing. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Double-layer versus single-layer bone-patellar tendon-bone anterior cruciate ligament reconstruction: a prospective randomized study with 3-year follow-up. (United States)

    Mei, Xiaoliang; Zhang, Zhenxiang; Yang, Jingwen


    To evaluate the clinical results of a randomized controlled trial of single-layer versus double-layer bone-patellar tendon-bone (BPTB) anterior cruciate ligament (ACL) reconstruction. Fifty-eight subjects who underwent primary ACL reconstruction with a BPTB allograft were prospectively randomized into two groups: single-layer reconstruction (n = 31) and double-layer reconstruction (n = 27). The following evaluation methods were used: clinical examination, KT-1000 arthrometer measurement, muscle strength, Tegner activity score, Lysholm score, subjective rating scale regarding patient satisfaction and sports performance level, graft retear, contralateral ACL tear, and additional meniscus surgery. Forty-eight subjects (24 in single-layer group and 24 in double-layer group) who were followed up for 3 years were evaluated. Preoperatively, there were no differences between the groups. At 3-year follow-up, the Lachman and pivot-shift test results were better in the double-layer group (P = 0.019 and P reconstruction, double-layer BPTB reconstruction was significantly better than single-layer reconstruction regarding anterior and rotational stability at 3-year follow-up. The results of KT measurements and the Lachman and pivot-shift tests were significantly better in the double-layer group, whereas there was no difference in the anterior drawer test results. The Tegner score was also better in the double-layer group; however, there were no differences in the other subjective findings.

  16. Aromatic structure degradation of single layer graphene on an amorphous silicon substrate in the presence of water, hydrogen and Extreme Ultraviolet light

    NARCIS (Netherlands)

    Mund, Baibhav Kumar; Sturm, J.M.; Lee, Christopher James; Bijkerk, Frederik


    In this paper we study the reaction of water and graphene under Extreme Ultraviolet (EUV) irradiation and in the presence of hydrogen. In this work, single layer graphene (SLG) on amorphous Si as an underlying substrate was dosed with water (0.75 ML) and exposed to EUV (λ = 13.5 nm, 92 eV) with

  17. Necrotizing Fasciitis Secondary to a Primary Suture for Anoperineal Trauma by Motorcycle Accident in a Healthy Adult

    Directory of Open Access Journals (Sweden)

    Susumu Saigusa


    Full Text Available A 41-year-old man experienced a swollen scrotum three days after a motorcycle accident and presented to our hospital. He had had a primary suture repair for anoperineal trauma in an outside hospital at the time of the injury. He presented to us with general fatigue, low grade fevers, and perineal pain. Abdominal computed tomography showed subcutaneous emphysema from the scrotum to the left chest. The sutured wound had foul-smelling discharge and white exudate. We made the diagnosis of necrotizing fasciitis and immediately opened the sutured wound and performed initial debridement and lavage with copious irrigation. We continued antibiotics and lavage of the wound until the infection was controlled. Fortunately, the necrotizing fasciitis did not worsen and he was discharged after 15 days. Our experience indicates that anoperineal injuries should not be closed without careful and intensive follow-up due to the potential of developing necrotizing fasciitis.

  18. Cosmetic outcomes of cesarean section scar; subcuticular suture versus intradermal buried suture. (United States)

    Yang, Juseok; Kim, Ki Hyung; Song, Yong Jung; Kim, Seung-Chul; Sung, Nayoung; Kim, Haneul; Lee, Dong Hyung


    The objective of the study was to compare cosmetic outcomes and overall satisfaction rate of cesarean section scar between conventional subcuticular suture and intradermal buried vertical mattress. Patients were enrolled to the study by chart review. A scar assessment was obtained retrospectively through a telephone survey. The patient component of the patient and observer scar assessment scale (POSAS) was utilized along with the overall satisfaction of the patient regarding their cesarean section scar and their willingness to choose the same skin closure technique when anticipating their next cesarean section. A total of 303 cases of cesarean section was recruited, 102 finished telephone surveys were calculated for the analyses. Subcuticular suture was regarded as control group (n=52) and intradermal buried suture as test group (n=50). The PSAS score of the test group (mean, 21.8) was lower than that of the control group (mean, 28), with a statistical significance ( P =0.02). Overall satisfaction rate did not differ between the two groups. Two parameters of the PSAS score and the level of overall satisfaction showed significant correlation (Pearson's r , -0.63; P cesarean sections over subcuticular stitch.

  19. A Mechanical Evaluation of Zone II Flexor Tendon Repair Using a Knotless Barbed Suture Versus a Traditional Braided Suture. (United States)

    Nayak, Aniruddh N; Nguyen, Dzi-Viet; Brabender, Robert C; Hiro, Matthew E; Miles, Jeremy J; Smithson, Ian R; Santoni, Brandon G; Stone, Jeffery D; Hess, Alfred V


    To determine repair site bulk, gliding resistance, work of flexion, and 1-mm gap formation force in zone II flexor tendon lacerations repaired with knotless barbed or traditional braided suture. Transverse zone II lacerations of the flexor digitorum profundus (FDP) tendon were created in 36 digits from 6 matched human cadaveric pairs. Repair was performed with 2-0 barbed suture (n = 18) or 3-0 polyethylene braided suture (n = 18). Pre- and postrepair cross-sectional area was measured followed by quantification of gliding resistance and work of flexion during cyclic flexion-extension loading at 10 mm/min. Thereafter, the repaired tendons were loaded to failure. The force at 1 mm of gap formation was recorded. Repaired FDP tendon cross-sectional area increased significantly from intact, with no difference noted between suture types. Gliding resistance and work of flexion were significantly higher for both suture repairs; however, we identified no significant differences in either nondestructive biomechanical parameters between repair types. Average 1-mm gap formation force with the knotless barbed suture (52 N) was greater than that of the traditional braided suture (43 N). We identified no significant advantage in using knotless barbed suture for zone II FDP repair in our primary, nondestructive mechanical outcomes in this in vitro study. In vivo studies may be warranted to determine if one suture method has an advantage with respect to the parameters tested at 4, 6, and 12 plus weeks postrepair and the degree of adhesion formation. The combined laboratory and clinical data, in additional to cost considerations, may better define the role of barbed knotless suture for zone II flexor tendon repair. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  20. Management of recurrent epistaxis in an anticoagulated patient by temporarily closing the nares with sutures. (United States)

    Eng, Chee-Yean; Yew, Teck-Aun; Ng, Wai-Siene; El-Hawrani, Amged S


    We describe an unusual case of recurrent, refractory anterior epistaxis in an 86-year-old man with two mechanical heart valves who was on permanent warfarin therapy. His numerous episodes of epistaxis were incited by chronic nose-picking and strong nose-blowing, practices that he continued to engage in despite repeated medical advice to stop. Stopping his anticoagulation therapy was not considered as a management option because of an unacceptably high risk that this would lead to a thromboembolic event. Eventually, we temporarily sutured his nares closed, and his nosebleeds ceased. The suturing was performed in the ward with local anesthesia. This procedure was simple to perform,fairly well tolerated, easily reversible, and highly effective.

  1. Bronchus anastomosis after sleeve resection for lung cancer: does the suture technique have an impact on postoperative complication rate? (United States)

    Palade, Emanuel; Holdt, Holger; Passlick, Bernward


    Bronchoplastic resections emerged as an alternative to pneumonectomy for patients with impaired pulmonary function and have gained popularity due to a marked decrease in morbidity and at least similar oncological outcome. Actual guidelines recommend sleeve resections whenever technically feasible, even in cases with adequate pulmonary reserve for pneumonectomy, in order to maximally preserve functional lung parenchyma. Various suture techniques were described; the existing evidence, however, is insufficient to recommend one of them as standard. The aim of this study was to compare two suture techniques for bronchus repair after sleeve resection. Two groups of patients from two separate institutions were retrospectively analysed. In Group A (n = 20), the anastomosis was performed with a running suture at the membranous part and an interrupted suture for the rest of the circumference. In Group B (n = 40), a telescoping continuous suture was used. Intra- and postoperative findings directly related to the anastomosis were compared. The parameters were assessed as absolute numbers and percentages; the statistical significance was determined using Pearson's χ(2) test for categorical variables and Student's t-test for continuous data (P resection type (predominance of the right upper lobe for Group B), the groups were comparable regarding patient characteristics. The intraoperative anastomotic assessment revealed: patency 100% in both groups, initial air tightness (100 vs 82.5%; P = 0.047) and buttressing 85 vs 5%. No suture revision was necessary in both groups. The analysis of anastomosis-related morbidity revealed no significant difference: atelectasis (1 in Group A and 2 in Group B; P = 1), reversible anastomotic changes (0 vs 2; P = 0.309), early stenosis (0 vs 0), bronchopleural fistula (1 vs 0; P = 0.154), bronchovascular fistula (0 vs 0), late stenosis (1 vs 0; P = 0.119) and reoperations (15 vs 5%; P = 0.186). The operative mortality rate was similar (2 vs 3; P

  2. The implementation of biofiltration systems, rainwater tanks and urban irrigation in a single-layer urban canopy model (United States)

    Demuzere, Matthias; Coutts, Andrew; Goehler, Maren; Broadbent, Ashley; Wouters, Hendrik; van Lipzig, Nicole; Gebert, Luke


    Urban vegetation is generally considered as a key tool to modify the urban energy balance through enhanced evapotranspiration (ET). Given that vegetation is most effective when it is healthy, stormwater harvesting and retention strategies (such as water sensitive urban design) could be used to support vegetation and promote ET. This study presents the implementation of a vegetated lined bio-filtration system (BFS) combined with a rainwater tank (RWT) and urban irrigation system in the single-layer urban canopy model Community Land Model-Urban. Runoff from roof and impervious road surface fractions is harvested and used to support an adequate soil moisture level for vegetation in the BFS. In a first stage, modelled soil moisture dynamics are evaluated and found reliable compared to observed soil moisture levels from biofiltration pits in Smith Street, Melbourne (Australia). Secondly, the impact of BFS, RWT and urban irrigation on ET is illustrated for a two-month period in 2012 using varying characteristics for all components. Results indicate that (i) a large amount of stormwater is potentially available for indoor and outdoor water demands, including irrigation of urban vegetation, (ii) ET from the BFS is an order of magnitude larger compared to the contributions from the impervious surfaces, even though the former only covers 10% of the surface fraction and (iii) attention should be paid to the cover fraction and soil texture of the BFS, size of the RWT and the surface fractions contributing to the collection of water in the RWT. Overall, this study reveals that this model development can effectuate future research with state-of-the-art urban climate models to further explore the benefits of vegetated biofiltration systems as a water sensitive urban design tool optimised with an urban irrigation system to maintain healthy vegetation.

  3. Full-thickness skin wound healing using autologous keratinocytes and dermal fibroblasts with fibrin: bilayered versus single-layered substitute. (United States)

    Idrus, Ruszymah Bt Hj; Rameli, Mohd Adha bin P; Low, Kiat Cheong; Law, Jia Xian; Chua, Kien Hui; Latiff, Mazlyzam Bin Abdul; Saim, Aminuddin Bin


    Split-skin grafting (SSG) is the gold standard treatment for full-thickness skin defects. For certain patients, however, an extensive skin lesion resulted in inadequacies of the donor site. Tissue engineering offers an alternative approach by using a very small portion of an individual's skin to harvest cells for propagation and biomaterials to support the cells for implantation. The objective of this study was to determine the effectiveness of autologous bilayered tissue-engineered skin (BTES) and single-layer tissue-engineered skin composed of only keratinocytes (SLTES-K) or fibroblasts (SLTES-F) as alternatives for full-thickness wound healing in a sheep model. Full-thickness skin biopsies were harvested from adult sheep. Isolated fibroblasts were cultured using medium Ham's F12: Dulbecco modified Eagle medium supplemented with 10% fetal bovine serum, whereas the keratinocytes were cultured using Define Keratinocytes Serum Free Medium. The BTES, SLTES-K, and SLTES-F were constructed using autologous fibrin as a biomaterial. Eight full-thickness wounds were created on the dorsum of the body of the sheep. On 4 wounds, polyvinyl chloride rings were used as chambers to prevent cell migration at the edge. The wounds were observed at days 7, 14, and 21. After 3 weeks of implantation, the sheep were euthanized and the skins were harvested. The excised tissues were fixed in formalin for histological examination via hematoxylin-eosin, Masson trichrome, and elastin van Gieson staining. The results showed that BTES, SLTES-K, and SLTES-F promote wound healing in nonchambered and chambered wounds, and BTES demonstrated the best healing potential. In conclusion, BTES proved to be an effective tissue-engineered construct that can promote the healing of full-thickness skin lesions. With the support of further clinical trials, this procedure could be an alternative to SSG for patients with partial- and full-thickness burns.

  4. Predicting Single-Layer Technetium Dichalcogenides (TcX₂, X = S, Se) with Promising Applications in Photovoltaics and Photocatalysis. (United States)

    Jiao, Yalong; Zhou, Liujiang; Ma, Fengxian; Gao, Guoping; Kou, Liangzhi; Bell, John; Sanvito, Stefano; Du, Aijun


    One of the least known compounds among transition metal dichalcogenides (TMDCs) is the layered triclinic technetium dichalcogenides (TcX2, X = S, Se). In this work, we systematically study the structural, mechanical, electronic, and optical properties of TcS2 and TcSe2 monolayers based on density functional theory (DFT). We find that TcS2 and TcSe2 can be easily exfoliated in a monolayer form because their formation and cleavage energy are analogous to those of other experimentally realized TMDCs monolayer. By using a hybrid DFT functional, the TcS2 and TcSe2 monolayers are calculated to be indirect semiconductors with band gaps of 1.91 and 1.69 eV, respectively. However, bilayer TcS2 exhibits direct-bandgap character, and both TcS2 and TcSe2 monolayers can be tuned from semiconductor to metal under effective tensile/compressive strains. Calculations of visible light absorption indicate that 2D TcS2 and TcSe2 generally possess better capability of harvesting sunlight compared to single-layer MoS2 and ReSe2, implying their potential as excellent light-absorbers. Most interestingly, we have discovered that the TcSe2 monolayer is an excellent photocatalyst for splitting water into hydrogen due to the perfect fit of band edge positions with respect to the water reduction and oxidation potentials. Our predictions expand the two-dimensional (2D) family of TMDCs, and the remarkable electronic/optical properties of monolayer TcS2 and TcSe2 will place them among the most promising 2D TMDCs for renewable energy application in the future.

  5. Sperm yield after single layer centrifugation with Androcoll-E is related to the potential fertility of the original ejaculate. (United States)

    Morrell, J M; Stuhtmann, G; Meurling, S; Lundgren, A; Winblad, C; Macias Garcia, B; Johannisson, A


    Many attempts have been made to identify laboratory tests that are predictive of sperm fertility, both to improve the quality of stallion semen doses for artificial insemination (AI) and to identify potential breeding sires if no fertility data are available. Sperm quality at the stud is mostly evaluated by assessing subjective motility, although this parameter can be poorly indicative of fertility. Sperm morphology and chromatin integrity in Swedish stallions are correlated to pregnancy rate after AI. Because single layer centrifugation (SLC) selects for spermatozoa with normal morphology and good chromatin, retrospective analysis was carried out to investigate whether sperm yield after SLC is linked to potential fertility. Commercial semen doses for AI from 24 stallions (five stallions with four ejaculates each, 19 stallions with three ejaculates each; n = 77) obtained during the breeding season were cooled, and sent overnight to the Swedish University of Agricultural Sciences in an insulated box for evaluation, with other doses being sent to studs for commercial AI. On arrival at Swedish University of Agricultural Sciences, the semen was used for SLC and also for evaluation of sperm motility, membrane integrity, chromatin integrity, and morphology. The seasonal pregnancy rates for each stallion were available. The yield of progressively motile spermatozoa after SLC (calculated as a proportion of the initial load) was found to be highly correlated with pregnancy rate (r = 0.75; P centrifugation is fast (30 minutes) and does not require expensive equipment, whereas other assays require a flow cytometer and/or specialist skills. An additional option could be to transport semen doses to a laboratory for SLC if the stud personnel do not want to perform the procedure themselves. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. The Strength of Transosseous Medial Meniscal Root Repair Using a Simple Suture Technique Is Dependent on Suture Material and Position. (United States)

    Robinson, James R; Frank, Evelyn G; Hunter, Alan J; Jermin, Paul J; Gill, Harinderjit S


    A simple suture technique in transosseous meniscal root repair can provide equivalent resistance to cyclic load and is less technically demanding to perform compared with more complex suture configurations, yet maximum yield loads are lower. Various suture materials have been investigated for repair, but it is currently not clear which material is optimal in terms of repair strength. Meniscal root anatomy is also complex; consisting of the ligamentous mid-substance (root ligament), the transition zone between the meniscal body and root ligament; the relationship between suture location and maximum failure load has not been investigated in a simulated surgical repair. (A) Using a knottable, 2-mm-wide, ultra-high-molecular-weight polyethylene (UHMWPE) braided tape for transosseous meniscal root repair with a simple suture technique will give rise to a higher maximum failure load than a repair made using No. 2 UHMWPE standard suture material for simple suture repair. (B) Suture position is an important factor in determining the maximum failure load. Controlled laboratory study. In part A, the posterior root attachment of the medial meniscus was divided in 19 porcine knees. The tibias were potted, and repair of the medial meniscus posterior root was performed. A suture-passing device was used to place 2 simple sutures into the posterior root of the medial meniscus during a repair procedure that closely replicated single-tunnel, transosseous surgical repair commonly used in clinical practice. Ten tibias were randomized to repair with No. 2 suture (Suture group) and 9 tibias to repair with 2-mm-wide knottable braided tape (Tape group). The repair strength was assessed by maximum failure load measured by use of a materials testing machine. Micro-computed tomography (CT) scans were obtained to assess suture positions within the meniscus. The wide range of maximum failure load appeared related to suture position. In part B, 10 additional porcine knees were prepared. Five

  7. Complications with mechanical suture use in colorectal surgery

    International Nuclear Information System (INIS)

    Bruno, G.; Ruso, L.; Gatti, A.; Quiros, F.; Balboa, O.


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

  8. Bacterial adhesion to suture material in a contaminated wound model: Comparison of monofilament, braided, and barbed sutures. (United States)

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


    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 barbs on Quill. From a microbiological perspective, barbed sutures can be recommended in aseptic surgery, but should only be used carefully in septic surgery. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:925-933, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

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

    Directory of Open Access Journals (Sweden)

    Erich K. Odermatt


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

  10. Preparation and applications of mechanically exfoliated single-layer and multilayer MoS₂ and WSe₂ nanosheets. (United States)

    Li, Hai; Wu, Jumiati; Yin, Zongyou; Zhang, Hua


    Although great progress has been achieved in the study of graphene, the small current ON/OFF ratio in graphene-based field-effect transistors (FETs) limits its application in the fields of conventional transistors or logic circuits for low-power electronic switching. Recently, layered transition metal dichalcogenide (TMD) materials, especially MoS2, have attracted increasing attention. In contrast to its bulk material with an indirect band gap, a single-layer (1L) MoS2 nanosheet is a semiconductor with a direct band gap of ~1.8 eV, which makes it a promising candidate for optoelectronic applications due to the enhancement of photoluminescence and high current ON/OFF ratio. Compared with TMD nanosheets prepared by chemical vapor deposition and liquid exfoliation, mechanically exfoliated ones possess pristine, clean, and high-quality structures, which are suitable for the fundamental study and potential applications based on their intrinsic thickness-dependent properties. In this Account, we summarize our recent research on the preparation, characterization, and applications of 1L and multilayer MoS2 and WSe2 nanosheets produced by mechanical exfoliation. During the preparation of nanosheets, we proposed a simple optical identification method to distinguish 1L and multilayer MoS2 and WSe2 nanosheets on a Si substrate coated with 90 and 300 nm SiO2. In addition, we used Raman spectroscopy to characterize mechanically exfoliated 1L and multilayer WSe2 nanosheets. For the first time, a new Raman peak at 308 cm(-1) was observed in the spectra of WSe2 nanosheets except for the 1L WSe2 nanosheet. Importantly, we found that the 1L WSe2 nanosheet is very sensitive to the laser power during characterization. The high power laser-induced local oxidation of WSe2 nanosheets and single crystals was monitored by Raman spectroscopy and atomic force microscopy (AFM). Hexagonal and monoclinic structured WO3 thin films were obtained from the local oxidization of single- to triple

  11. Mechanical testing of orthopedic suture material used for extra-articular stabilization of canine cruciate ligament-deficient stifles. (United States)

    Rose, Nathan D; Goerke, Derek; Evans, Richard B; Conzemius, Michael G


    To determine (1) if braided, polyblend orthopedic suture materials are mechanically superior to monofilament nylon leader and (2) have mechanical properties similar to biomechanical properties of the canine cruciate ligament. Different suture material types. Mechanical testing was performed on 5 different orthopedic suture materials: 80# test Mason monofilament nylon leader (MNL), FiberTape (FT), FiberWire (FW), Xgen OrthoFiber (XOF), and LigaFiba (LF) using a servohydraulic materials-testing machine. Materials were loaded to failure while collecting data for tensile strength, load at 3 mm and 5 mm of elongation and stiffness. Cyclic elongation of each suture material was tested under physiologic loading between 70 and 150 N for 1000 cycles using 3 mm of elongation to describe excessive elongation. Load at 3 mm of elongation and performance during cyclic testing were compared to previously published physiologic loads in the dog stifle. Ultimate tensile strength was greatest with LF, followed by XOF that was stronger than FT and FW, and the weakest was MNL. LF was the stiffest of all tested materials at 3 mm of elongation. Cyclic elongation was greatest for the MNL elongating 3.75 mm after 1000 cycles. All polyblend braided materials continued to elongate throughout the 1000 cycles under physiologic loads. Polyblend suture materials are stronger and elongate less than MNL in pure tension. The mechanical performance of all sutures tested is questionable when compared with the mechanical demands of the normal stifle in a mid-sized dog. © Copyright 2011 by The American College of Veterinary Surgeons.


    Directory of Open Access Journals (Sweden)

    Jafar Nader


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

  13. Flexor Tendon Repair With Looped Suture: 1 Versus 2 Knots. (United States)

    Gil, Joseph A; Skjong, Christian; Katarincic, Julia A; Got, Christopher


    To assess the strength of flexor tendon repair with looped suture. We hypothesized that, after passing the intact looped suture in the desired repair configuration, splitting the loop and tying 2 independent knots would increase the strength of flexor tendon repair. Thirty-two flexor tendons were harvested and were sharply transected in zone II. The tendons were repaired with a 4-strand core suture repair using 3-0 looped nonabsorbable nylon suture. The harvested tendons were randomly assigned and repaired with either a 1- or a 2-knot construct. The repaired flexor tendons were fixed in a servohydraulic material testing system and were loaded to failure either with uniaxial tension or cyclically. The average force at failure was 43 N for the 1-knot repair and 28 N for the 2-knot repair. The mode of failure of 15 of the flexor tendon repairs that were cyclically loaded to failure was suture pull-out. The average number of cycles and force in cyclic testing that caused failure of flexor tendon repairs was 134 cycles and 31 N for tendons repaired with looped 3-0 suture tied with 1 knot and 94 cycles and 33 N for tendons repaired with looped 3-0 suture tied with 2 knots. Our hypothesis was disproved by the results of this study. This study suggests that, when using looped suture, tying 2 independent knots instead of tying a single knot does not increase the strength of the flexor tendon repair. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  14. [Clinical experience in using a metallic suture in eye microsurgery]. (United States)

    Kumar Vinod, Dushin N V


    The use of a metallic suture in eye microsurgery is described in the paper. The metallic suture made from a 0.05-0.05 mm vanadic stainless steel wire (corresponding to 8:0) was applied in 1202 cataract extractions, penetrating injuries, antiglaucomatous surgeries and in removal of pterygium at the medical-and-sanitary facility of steel works in the town of Bokaro (India). The observation period ranged, on the average, from 3 months to 3 years. There were no complications during the procedure of applying the suture. However, it caused a minor response in the ocular tissues during the early postoperative period. Small bullae were observed in the corneal surface near the suture in 7 cases (0.58%), which disappeared spontaneously in 3-4 days. Irritations inflicted by the suture ends were registered in 2.58% of cases (31 patients). The mean postoperative astigmatism was, 3 months after surgery, 1.65 diopters. The sutures were removed in 132 cases (10.98%), including in 16 patients with irritation, and in 116 patients for the purpose of correcting a high astigmatism. The share of patients with a visual acuity of 0.5 and higher was, in one week, 43.59% and went up, one month later, to 78.20%. The suture was well tolerated by patients, it was quickly covered by the corneal epithelium, there was no rejection and it can be easily manufactured. The suture is sterilized by routine techniques without need for any extra treatment before use; it is a reactive, biologically inactive, efficient, convenient and causes minimal operative and postoperative complications.

  15. Oesophageal flap valvuloplasty and wrapping suturing prevent gastrooesophageal reflux disease in dogs after oesophageal anastomosis (United States)

    Dai, Ji-Gang; Liu, Quan-Xing; Den, Xu-Feng; Min, Jia-Xin


    AIM: To examine the efficiency of oesophageal flap valvuloplasty and wrapping suturing technique in decreasing the rate of postoperative gastrooesophageal reflux disease in a dog model. METHODS: We operated on 10 dogs in this study. First, we resected a 5-cm portion of the distal oesophagus and then restored the continuity of the oesophageal and gastric walls by end-to-end anastomosis. A group of five dogs was subjected to the oesophageal flap valvuloplasty and wrapping suturing technique, whereas another group (control) of five dogs was subjected to the stapling technique after oesophagectomy. The symptom of gastrooesophageal reflux was recorded by 24-h pH oesophageal monitoring. Endoscopy and barium swallow examination were performed on all dogs. Anastomotic leakage was observed by X-ray imaging, whereas benign anastomotic stricture and mucosal damage were observed by endoscopy. RESULTS: None of the 10 dogs experienced anastomotic leakage after oesophagectomy. Four dogs in the new technology group resumed regular feeding, whereas only two of the dogs in the control group tolerated solid food intake. pH monitoring demonstrated that 25% of the dogs in the experimental group exhibited reflux and that none had mucosal damage consistent with reflux. Conversely, both reflux and mucosal damage were observed in all dogs in the control group. CONCLUSION: The oesophageal flap valvuloplasty and wrapping suturing technique can improve the postoperative quality of life through the long-term elimination of reflux oesophagitis and decreased stricture formation after primary oesophageal anastomosis. PMID:25516655

  16. Oesophageal flap valvuloplasty and wrapping suturing prevent gastrooesophageal reflux disease in dogs after oesophageal anastomosis. (United States)

    Dai, Ji-Gang; Liu, Quan-Xing; Den, Xu-Feng; Min, Jia-Xin


    To examine the efficiency of oesophageal flap valvuloplasty and wrapping suturing technique in decreasing the rate of postoperative gastrooesophageal reflux disease in a dog model. We operated on 10 dogs in this study. First, we resected a 5-cm portion of the distal oesophagus and then restored the continuity of the oesophageal and gastric walls by end-to-end anastomosis. A group of five dogs was subjected to the oesophageal flap valvuloplasty and wrapping suturing technique, whereas another group (control) of five dogs was subjected to the stapling technique after oesophagectomy. The symptom of gastrooesophageal reflux was recorded by 24-h pH oesophageal monitoring. Endoscopy and barium swallow examination were performed on all dogs. Anastomotic leakage was observed by X-ray imaging, whereas benign anastomotic stricture and mucosal damage were observed by endoscopy. None of the 10 dogs experienced anastomotic leakage after oesophagectomy. Four dogs in the new technology group resumed regular feeding, whereas only two of the dogs in the control group tolerated solid food intake. pH monitoring demonstrated that 25% of the dogs in the experimental group exhibited reflux and that none had mucosal damage consistent with reflux. Conversely, both reflux and mucosal damage were observed in all dogs in the control group. The oesophageal flap valvuloplasty and wrapping suturing technique can improve the postoperative quality of life through the long-term elimination of reflux oesophagitis and decreased stricture formation after primary oesophageal anastomosis.

  17. A New Coating for Non-resorbable Surgical Suture

    Directory of Open Access Journals (Sweden)

    Ahmed Salah Hameed


    Full Text Available Suture is a biomaterial used to approximate wound edges to facilitate the healing process. This task could be compromised as a result of wound infection. Zinc is an element that has antibacterial action and can be a member of silicate glasses. The zinc-silicate glasses can be used as a coating for surgical suture to combat wound infection. However, zinc has a negative effect on glass degradation and its  antibacterial action is a pH sensitive. In this work, silicate glasseswith ZnO at 14 and 17 mole% were used as a coating for non-resorbable Mersilk suture using a slurry-dipping technique. The coating morphology was studied using SEM and itsanti-bacterial action was investigated in vitroagainstgram positive and negative bacteria at neutral and acidic conditions.The effect of the coating on tensile strength of the sutures wasstudied as well.The results revealed that the coatingwas well-adhered to the suture and had anti-bacterial action atacidic condition.The coating had no effect on the tensile strength of the surgical suture

  18. Suture techniques in nasal tip sculpture: current concepts. (United States)

    Lo, S; Rowe-Jones, J


    The three-dimensional anatomy and conspicuous location of the nasal tip makes it one of the most challenging sites of facial plastic surgery. This article reviews literature on nasal tip sculpture using suture techniques, as well as the authors' own experience. A search was conducted using Pubmed, the Google internet search engine and the authors' files, using the keywords 'nasal tip', 'suture', 'rhinoplasty' and 'septorhinoplasty'. Common nasal tip suture techniques and suture algorithms are presented, along with a summary of the indications and side effects of each technique. Predictable long-term results are more likely to occur with minimal local tissue excision. Suture techniques remodel the shape of the nasal tip by altering the configuration of, and the relationship between, the tip cartilages and their supporting structures; they also preserve nasal tip anatomy and limit resection. Intra-operatively, the effects are immediately visible, and can be adjusted or reversed. Tip sutures should therefore be considered instead of tissue excision whenever possible.

  19. Development of braided drug-loaded nanofiber sutures

    International Nuclear Information System (INIS)

    Hu Wen; Huang Zhengming; Liu Xiangyang


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

  20. Self-Assembly of Single-Layer CoAl-Layered Double Hydroxide Nanosheets on 3D Graphene Network Used as Highly Efficient Electrocatalyst for Oxygen Evolution Reaction. (United States)

    Ping, Jianfeng; Wang, Yixian; Lu, Qipeng; Chen, Bo; Chen, Junze; Huang, Ying; Ma, Qinglang; Tan, Chaoliang; Yang, Jian; Cao, Xiehong; Wang, Zhijuan; Wu, Jian; Ying, Yibin; Zhang, Hua


    A non-noble metal based 3D porous electrocatalyst is prepared by self-assembly of the liquid-exfoliated single-layer CoAl-layered double hydroxide nanosheets (CoAl-NSs) onto 3D graphene network, which exhibits higher catalytic activity and better stability for electrochemical oxygen evolution reaction compared to the commercial IrO2 nanoparticle-based 3D porous electrocatalyst. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Raman excitation profiles of hybrid systems constituted by single-layer graphene and free base phthalocyanine: Manifestations of two mechanisms of graphene-enhanced Raman scattering

    Czech Academy of Sciences Publication Activity Database

    Uhlířová, T.; Mojzeš, P.; Melníková Komínková, Zuzana; Kalbáč, Martin; Sutrová, Veronika; Šloufová, I.; Vlčková, B.


    Roč. 48, č. 10 (2017), s. 1270-1281 ISSN 0377-0486 R&D Projects: GA ČR(CZ) GA15-01953S Institutional support: RVO:61388955 ; RVO:61389013 Keywords : graphene -enhanced Raman scattering * single-layer graphene * free base phthalocyanine * Raman excitation profiles * photoinduced charge transfer Subject RIV: CF - Physical ; Theoretical Chemistry; CD - Macromolecular Chemistry (UMCH-V) OBOR OECD: Physical chemistry; Polymer science (UMCH-V) Impact factor: 2.969, year: 2016

  2. Raman excitation profiles of hybrid systems constituted by single-layer graphene and free base phthalocyanine: Manifestations of two mechanisms of graphene-enhanced Raman scattering

    Czech Academy of Sciences Publication Activity Database

    Uhlířová, T.; Mojzeš, P.; Melníková Komínková, Zuzana; Kalbáč, Martin; Sutrová, Veronika; Šloufová, I.; Vlčková, B.


    Roč. 48, č. 10 (2017), s. 1270-1281 ISSN 0377-0486 R&D Projects: GA ČR(CZ) GA15-01953S Institutional support: RVO:61388955 ; RVO:61389013 Keywords : graphene-enhanced Raman scattering * single-layer graphene * free base phthalocyanine * Raman excitation profiles * photoinduced charge transfer Subject RIV: CF - Physical ; Theoretical Chemistry; CD - Macromolecular Chemistry (UMCH-V) OBOR OECD: Physical chemistry; Polymer science (UMCH-V) Impact factor: 2.969, year: 2016

  3. Common electronic origin of superconductivity in (Li,Fe)OHFeSe bulk superconductor and single-layer FeSe/SrTiO3 films. (United States)

    Zhao, Lin; Liang, Aiji; Yuan, Dongna; Hu, Yong; Liu, Defa; Huang, Jianwei; He, Shaolong; Shen, Bing; Xu, Yu; Liu, Xu; Yu, Li; Liu, Guodong; Zhou, Huaxue; Huang, Yulong; Dong, Xiaoli; Zhou, Fang; Liu, Kai; Lu, Zhongyi; Zhao, Zhongxian; Chen, Chuangtian; Xu, Zuyan; Zhou, X J


    The mechanism of high-temperature superconductivity in the iron-based superconductors remains an outstanding issue in condensed matter physics. The electronic structure plays an essential role in dictating superconductivity. Recent revelation of distinct electronic structure and high-temperature superconductivity in the single-layer FeSe/SrTiO3 films provides key information on the role of Fermi surface topology and interface in inducing or enhancing superconductivity. Here we report high-resolution angle-resolved photoemission measurements on the electronic structure and superconducting gap of an FeSe-based superconductor, (Li0.84Fe0.16)OHFe0.98Se, with a Tc at 41 K. We find that this single-phase bulk superconductor shows remarkably similar electronic behaviours to that of the superconducting single-layer FeSe/SrTiO3 films in terms of Fermi surface topology, band structure and the gap symmetry. These observations provide new insights in understanding high-temperature superconductivity in the single-layer FeSe/SrTiO3 films and the mechanism of superconductivity in the bulk iron-based superconductors.

  4. Why make monofilament sutures out of polyvinylidene fluoride? (United States)

    Urban, E; King, M W; Guidoin, R; Laroche, G; Marois, Y; Martin, L; Cardou, A; Douville, Y


    In recent years some clinical reports have associated suture failures with polypropylene monofilaments. Therefore there is interest in developing an alternative suture material that is less thrombogenic than polyester and similar in handling characteristics but less prone to mechanical failure than polypropylene. To this end, Peters Laboratoire Pharmaceutique has developed a new monofilament suture material from polyvinylidene fluoride (PVDF), which has been subjected to a special treatment to modify its crystalline form and level of crystallinity. The purpose of this study was to evaluate its mechanical, chemical, and biologic properties and to compare its performance, in a peripheral vascular application, to that of a polypropylene control. A series of in vitro tests were performed to study the morphology, tensile properties, creep, surface chemistry, thermal characteristics, and resistance to iatrogenic trauma. In addition, an in vivo trial was undertaken in which vascular prostheses anastomosed with either PVDF or polypropylene sutures were implanted as a thoracoabdominal bypass for 6 months in the dog. Histologic and degradation analyses were performed on the explants. The results from the mechanical tests on 4-0, 5-0, and 6-0 PVDF and polypropylene sutures demonstrated that although both materials have similar breaking strengths, the PVDF has a higher extension at break, has less delayed extension when under tensile creep testing, and suffers less trauma than the polypropylene when compressed by a standard needle holder. While chemical analyses found evidence of surface oxidation on both types of sutures, thermal analysis confirmed that the level of crystallinity of the PVDF polymer is higher than that of the polypropylene control. During the pilot study in animals, PVDF sutures were found to have good handling and frictional characteristics that facilitated the tying of knots. Histologic analysis of the explants found no inflammatory cells in the tissue

  5. Arthroscopic Trapeziectomy With Suture Button Suspensionplasty (United States)

    Landes, Genevieve; Gaspar, Michael P.; Goljan, Peter; Jacoby, Sidney M.; Bachoura, Abdo; Culp, Randall W.


    Background: Arthroscopic trapeziectomy with suture button suspensionplasty (ATBS) is a relatively new surgical option for the treatment of thumb carpometacarpal (CMC) osteoarthritis. Although ATBS has many potential benefits over alternative surgical treatments for CMC arthritis, little data exist regarding its safety and complication rates. The purpose of this study was to demonstrate that ATBS is associated with a low risk of complications within 1 year of surgery. Methods: A retrospective review of patients treated with ATBS by one senior hand surgeon over a span of 3 years was performed. Results: A total of 153 cases of ATBS were performed in 136 patients. Ninety-seven cases involved arthroscopic hemitrapeziectomies, and 56 involved arthroscopic complete trapeziectomies. There were 44 males and 92 females with a mean age of 62. Thirty-eight percent of the cases were graded as Eaton stage IV, 46% stage III, and 14% stage II CMC arthritis, while 3 cases (2%) were performed as revisions. Mean follow-up duration was 58 weeks. Mean preoperative key pinch strength of the affected versus the unaffected side was 92% compared with 95% postoperatively. Revision surgery was performed in 9 out of 153 cases (<6%). Of those 9 cases, 5 had additional minor bony debridement with subsequent improvement in pain, 3 had the implant repositioned due to button prominence, and 1 patient presented with osteomyelitis of the first and second metacarpals that was successfully treated with button removal and an antibiotic regimen. Conclusions: ATBS is a safe, minimally invasive procedure for treatment of symptomatic stages II through IV thumb CMC arthritis. PMID:27390569

  6. [Treatment of calcaneal avulsion fractures with twinfix suture anchors fixation]. (United States)

    Zhao, Bin-xiu; Wang, Kun-zheng; Wang, Chun-sheng; Xie, Yue; Dai, Zhi-tang; Liu, Gang; Liu, Wei-dong


    For the calcaneal avulsion fracture, the current method is more commonly used screws or Kirschner wire to fix fracture fragment. This article intended to explore the feasibility and clinical efficacy for the treatment of avulsion fractures with TwinFix suture anchors. From July 2007 to November 2010, 21 patients were reviewed, including 15 males and 6 females, ranging in age from 49 to 65 years,with a mean of 58.7 years. Twelve patients had nodules in the right heel and 9 patients had nodules in the left heel. All the patients had closed fractures. The typical preoperative symptoms of the patients included pain in the upper heel and weak in heel lift. Body examination results: palpable sense of bone rubbing in the back of the heel, and swelling in the heel. Surgery treatment with TwinFix suture anchors performed as follows : to fix TwinFix suture anchors into the calcaneal body, then to drill the fracture block, to make the double strand suture through the fracture holes, to knot the suture eachother to fix the block, and to use stitch to fix the remaining suture in the Achilles tendon in order to improve the block fixation. The criteria of the AOFAS Foot and Ankle Surgery by the United States Association of ankle-rear foot functional recovery was used to evaluate the Achilles tendon. Total average score was (95.5 +/- 3.12) points, including pain items of(38.5 +/- 2.18) points,the average score of functional items of (49.5 +/- 3.09) points,and power lines of 10 points in all patients. Twenty-one patients got an excellent result, 16 good and 5 poor. The methods of treatment for the calcaneal avulsion fractures with TwinFix suture anchors is a simple operation, and have excellent clinical effect, which is worthy of promotion.

  7. Mesh fixation with a barbed anchor suture results in significantly less strangulation of the abdominal wall. (United States)

    Lyons, Calvin; Joseph, Rohan; Salas, Nilson; Reardon, Patrick R; Bass, Barbara L; Dunkin, Brian J


    Laparoscopic ventral hernia repair using an underlay mesh frequently requires suture fixation across the abdominal wall, which results in significant postoperative pain. This study investigates the utility of a novel mesh fixation technique to reduce the strangulation force on the abdominal wall. Multiple 2-cm(2) pieces of polyester mesh (Parietex Composite, Covidien) were placed as an underlay against a porcine abdominal wall. Fixation was accomplished using either the standard 0-polyglyconate or the 0-polyglyconate barbed anchor suture designed to hold in tissue without the need to tie a knot (V-Loc 180; Covidien). Suture fixation began with a stab wound incision in the skin. A suture-passing device then was used to pass the suture across the abdominal wall and through the mesh. The suture passer was removed and reintroduced through the same stab wound incision but at a different fascial entry point 1.5 cm away. The tail of the suture was grasped and pulled up through both the mesh and the abdominal wall, creating a full-thickness U-stitch. One tail of the suture was attached to a tensiometer, and the strangulation force on the abdominal wall was measured while the suture was tied (standard) or looped (barbed). To compare pullout force, the tensiometer was attached to either the mesh or the suture, and traction was applied until material failure or suture pull through. Results are expressed as mean ± standard deviation. Comparisons were performed using Student's t-test. Eight pieces of mesh were placed for each suture. The average force required to secure the barbed suture (0.59 ± 0.08 kg) was significantly less than the force needed to secure the standard suture (2.17 ± 0.58 kg) (P < 0.0001). Table 1 compares the suture pullout forces with the mesh failure forces. Although the pullout force for the standard suture is significantly greater than for the barbed suture, both sutures have a pullout strength significantly greater than the mesh failure force. Table

  8. Positioning of the cross-stitch on the modified Kessler core tendon suture. (United States)

    Gil-Santos, L; Monleón-Pradas, M; Gomar-Sancho, F; Más-Estellés, J


    Cryopreserved human tendons were sutured with different variations of a modified Kessler-type grasping suture in a series of different designs in order to assess the influence of the distance between the cross-stitch on the core suture (5 and 10 mm from the cut tendon edge) on the peripheral suture. An original mathematical model was employed to explain the mechanical behavior (strength, deformation, and distribution of load) of the different suture designs. The effect of the peripheral epitendinous suture, combined with the distance of the core suture, was evaluated. The variation of core suture distance had no relevant consequences on the overall resilience of the design. However, increasing the distance between the cross-stitches of the core suture reduces the deformation that is absorbed not only by the core suture itself but also by the peripheral suture. Adding a peripheral epitendinous suture to a 10-mm design almost doubles the breaking load in absolute values. The mathematical model predicts that the peripheral suture will support a greater load when the distance of the core suture cross-stitches is increased. The evidence level is II. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Primary suture of amputation wound: pro et contra. (United States)

    Muminagic, Sahib N


    During the First World War and the Second World War more than 80 % of wounded persons had injuries of upper or lower limbs. In the recent war in the Former Yugoslavia the percentage of persons with these injuries was above 80%. Each war is also characterized by the high percentage of wounded persons with amputations of upper or lower extremities. These amputations occurred mostly in the cases of polytrauma. In other cases we faced with severely wounded extremities with an extensive destruction of soft tissues, bones, blood vessels and joints, where the amputation is the only possible intervention to save the patient. In the previous World Wars, the surgeons have tried to shorten the time of treatment and to accept the surgical technique, by the application of primary suture of the wound. During the aggression on Bosnia and Herzegovina we were faced with a large number of wounded persons with amputations i.e. cases where we applied the primary suture. The results were still surprising and in many cases the wounds had primarily healed. The results were better when they were using primary suture on the upper extremities, measured at 61.9 % while the percentage of using the same suture on the lower limbs was of 48.8 %. The results of the war year 1995 were improved in comparison to the percentages listed above. The statistical analysis indicated that early application of the primary suture to the amputation wound was possible and largely successful, but, only when performed under certain conditions.


    Directory of Open Access Journals (Sweden)

    Fırat SELVİ


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

  11. A generalized mechanical model for suture interfaces of arbitrary geometry (United States)

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


    Suture interfaces with a triangular wave form commonly found in nature have recently been shown to exhibit exceptional mechanical behavior, where geometric parameters such as amplitude, frequency, and hierarchy can be used to nonlinearly tailor and amplify mechanical properties. In this study, using the principle of complementary virtual work, we formulate a generalized, composite mechanical model for arbitrarily-shaped interdigitating suture interfaces in order to more broadly investigate the influence of wave-form geometry on load transmission, deformation mechanisms, anisotropy, and stiffness, strength, and toughness of the suture interface for tensile and shear loading conditions. The application of this suture interface model is exemplified for the case of the general trapezoidal wave-form. Expressions for the in-plane stiffness, strength and fracture toughness and failure mechanisms are derived as nonlinear functions of shape factor β (which characterizes the general trapezoidal shape as triangular, trapezoidal, rectangular or anti-trapezoidal), the wavelength/amplitude ratio, the interface width/wavelength ratio, and the stiffness and strength ratios of the skeletal/interfacial phases. These results provide guidelines for choosing and tailoring interface geometry to optimize the mechanical performance in resisting different loads. The presented model provides insights into the relation between the mechanical function and the morphological diversity of suture interface geometries observed in natural systems.

  12. Mechanical Behavior of Bio-inspired Model Suture Joints (United States)

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


    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.

  13. Hand movements in laparoscopic suturing: a simple vector analysis. (United States)

    Hansen, A J; Schlinkert, R T


    Laparoscopic suturing is a complex task that is vital to the performance of many advanced laparoscopic procedures. Mastery can be difficult and problematic for surgical trainees. We present a description of hand movements in laparoscopic suturing. Complex maneuvers are simplified into linear motions using vectors. The analysis is intended to be a tool for training in the art of laparoscopic surgery. Linear hand movements in the x and y axes produce opposite motions at the instrument tip. Position along the z axis influences the extent of hand movement relative to the instrument tip. Rotational movements of the hand produce an equal rotation of the instrument tip. Revolution is a complex motion that combines movements in x and y axes. Vector analysis reveals that the arc of revolution must be reversed to produce the desired needle motion. A conceptual understanding of hand-movement vectors facilitates the efficient mastery of the complex skills required for laparoscopic suturing.

  14. An absorbable thread suture technique to treat snoring. (United States)

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


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

  15. Virtual interactive suturing for the Fundamentals of Laparoscopic Surgery (FLS). (United States)

    Qi, Di; Panneerselvam, Karthikeyan; Ahn, Woojin; Arikatla, Venkata; Enquobahrie, Andinet; De, Suvranu


    Suturing with intracorporeal knot-tying is one of the five tasks of the Fundamentals of Laparoscopic Surgery (FLS), which is a pre-requisite for board certification in general surgery. This task involves placing a short suture through two marks in a penrose drain and then tying a double-throw knot followed by two single-throw knots using two needle graspers operated by both hands. A virtual basic laparoscopic skill trainer (VBLaST©) is being developed to represent the virtual versions of the FLS tasks, including automated, real time performance measurement and feedback. In this paper, we present the development of a VBLaST suturing simulator (VBLaST-SS©). Developing such a simulator involves solving multiple challenges associated with fast collision detection, response and force feedback. In this paper, we present a novel projection-intersection based knot detection method, which can identify the validity of different types of knots at haptic update rates. A simple and robust edge-edge based collision detection algorithm is introduced to support interactive knot tying and needle insertion operations. A bimanual hardware interface integrates actual surgical instruments with haptic devices enabling not only interactive rendering of force feedback but also realistic sensation of needle grasping, which realizes an immersive surgical suturing environment. Experiments on performing the FLS intracorporeal suturing task show that the simulator is able to run on a standard personal computer at interactive rates. VBLaST-SS© is a computer-based interactive virtual simulation system for FLS intracorporeal knot-tying suturing task that can provide real-time objective assessment for the user's performance. Copyright © 2017 Elsevier Inc. All rights reserved.


    Directory of Open Access Journals (Sweden)



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

  17. Force Comparison of Commercially Available Transfascial Suture Passers. (United States)

    Shope, Alexander J; Winder, Joshua S; Bliggenstorfer, Jonathan T; Crowell, Kristen T; Haluck, Randy S; Pauli, Eric M


    Transfascial suture passers (TSPs) are a commonly used surgical tool available in a wide array of tip configurations. We assessed the insertion force of various TSPs in an ex vivo porcine model. Uniform sections of porcine abdominal wall were secured to a 3D-printed platform. Nine TSPs were passed through the abdominal wall both without and with prolene suture under the following scenarios: abdominal wall only and abdominal wall plus underlay ePTFE or composite ePTFE/polypropylene mesh. Insertion forces were recorded in Newton (N). When passed without suture through the abdominal wall, smaller diameter TSPs required less insertional force (1.50 ± 0.17 N vs 9.68 ± 1.50 N [ P = 0.00072]). Through composite mesh, the solid tipped TSPs required less force than hollow tipped ones (3.87 ± 0.25 N vs 7.88 ± 0.20 N [ P = 0.00026]). Overall, smaller diameter TSPs required less force than the larger TSPs when passed through ePTFE empty (Gore 2.95 ± 0.83 N vs Carter-Thomason 16.07 ± 2.10 N [ P = .0005]) or with suture (Gore 8.37 ± 2.59 N vs Carter-Thomason 19.12 ± 1.10 N [ P = .003]). Diameter plays the greatest role in the force required for TSP penetration. However, when passed through underlay mesh or while holding suture, distal tip shape, the mechanism of suture holding, and shaft diameter all contribute to the forces necessary for penetration. These factors should be considered when choosing a TSP for intraoperative use.

  18. Alveolar ridge preservation with an open-healing approach using single-layer or double-layer coverage with collagen membranes. (United States)

    Choi, Ho-Keun; Cho, Hag-Yeon; Lee, Sung-Jo; Cho, In-Woo; Shin, Hyun-Seung; Koo, Ki-Tae; Lim, Hyun-Chang; Park, Jung-Chul


    The aim of this prospective pilot study was to compare alveolar ridge preservation (ARP) procedures with open-healing approach using a single-layer and a double-layer coverage with collagen membranes using radiographic and clinical analyses. Eleven molars from 9 healthy patients requiring extraction of the maxillary or mandibular posterior teeth were included and allocated into 2 groups. After tooth extraction, deproteinized bovine bone mineral mixed with 10% collagen was grafted into the socket and covered either with a double-layer of resorbable non-cross-linked collagen membranes (DL group, n=6) or with a single-layer (SL group, n=5). Primary closure was not obtained. Cone-beam computed tomography images were taken immediately after the ARP procedure and after a healing period of 4 months before implant placement. Radiographic measurements were made of the width and height changes of the alveolar ridge. All sites healed without any complications, and dental implants were placed at all operated sites with acceptable initial stability. The measurements showed that the reductions in width at the level 1 mm apical from the alveolar crest (including the bone graft) were -1.7±0.5 mm in the SL group and -1.8±0.4 mm in the DL group, and the horizontal changes in the other areas were also similar in the DL and SL groups. The reductions in height were also comparable between groups. Within the limitations of this study, single-layer and double-layer coverage with collagen membranes after ARP failed to show substantial differences in the preservation of horizontal or vertical dimensions or in clinical healing. Thus, both approaches seem to be suitable for open-healing ridge preservation procedures.

  19. Comparison of light out-coupling enhancements in single-layer blue-phosphorescent organic light emitting diodes using small-molecule or polymer hosts

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yung-Ting [Institute of Chemistry, Academia Sinica, Taipei, Taiwan 11529, Taiwan (China); Department of Electrical Engineering, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan 10617, Taiwan (China); Liu, Shun-Wei [Department of Electronic Engineering, Mingchi University of Technology, New Taipei, Taiwan 24301, Taiwan (China); Yuan, Chih-Hsien; Lee, Chih-Chien [Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 10607, Taiwan (China); Ho, Yu-Hsuan; Wei, Pei-Kuen [Research Center for Applied Science Academia Sinica, Taipei, Taiwan 11527, Taiwan (China); Chen, Kuan-Yu [Chilin Technology Co., LTD, Tainan City, Taiwan 71758, Taiwan (China); Lee, Yi-Ting; Wu, Min-Fei; Chen, Chin-Ti, E-mail:, E-mail: [Institute of Chemistry, Academia Sinica, Taipei, Taiwan 11529, Taiwan (China); Wu, Chih-I, E-mail:, E-mail: [Department of Electrical Engineering, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan 10617, Taiwan (China)


    Single-layer blue phosphorescence organic light emitting diodes (OLEDs) with either small-molecule or polymer hosts are fabricated using solution process and the performances of devices with different hosts are investigated. The small-molecule device exhibits luminous efficiency of 14.7 cd/A and maximum power efficiency of 8.39 lm/W, which is the highest among blue phosphorescence OLEDs with single-layer solution process and small molecular hosts. Using the same solution process for all devices, comparison of light out-coupling enhancement, with brightness enhancement film (BEF), between small-molecule and polymer based OLEDs is realized. Due to different dipole orientation and anisotropic refractive index, polymer-based OLEDs would trap less light than small molecule-based OLEDs internally, about 37% better based simulation results. In spite of better electrical and spectroscopic characteristics, including ambipolar characteristics, higher carrier mobility, higher photoluminescence quantum yield, and larger triplet state energy, the overall light out-coupling efficiency of small molecule-based devices is worse than that of polymer-based devices without BEF. However, with BEF for light out-coupling enhancement, the improved ratio in luminous flux and luminous efficiency for small molecule based device is 1.64 and 1.57, respectively, which are significantly better than those of PVK (poly-9-vinylcarbazole) devices. In addition to the theoretical optical simulation, the experimental data also confirm the origins of differential light-outcoupling enhancement. The maximum luminous efficiency and power efficiency are enhanced from 14.7 cd/A and 8.39 lm/W to 23 cd/A and 13.2 lm/W, respectively, with laminated BEF, which are both the highest so far for single-layer solution-process blue phosphorescence OLEDs with small molecule hosts.

  20. Effect of robotic manipulation on unidirectional barbed suture integrity: evaluation of tensile strength and sliding force. (United States)

    Kaushik, Dharam; Clay, Kevin; Hossain, S G M; Park, Eugene; Nelson, Carl A; LaGrange, Chad A


    One of the more challenging portions of robot-assisted radical prostatectomy (RARP) is the urethrovesical anastomosis. Because of this, a unidirectional absorbable barbed suture (V-Loc(™)) has been used to complete the anastomosis with better efficiency and less tension. The effect of robotic needle driver manipulation on barbed suture is unknown. Therefore, the aim of this study is to determine whether robotic manipulation decreases the tensile strength and peak sliding force of V-Loc barbed suture. Fifty-six V-Loc sutures were compared with 56 Maxon sutures. All sutures were 3-0 caliber. Half of the sutures in each group were manipulated with a da Vinci(®) robot large needle driver five times over a 5 cm length of suture. The other half was not manipulated. Breaking force was determined by placing sutures in a Bose ElectroForce load testing device. For sliding force testing, 28 V-Loc sutures were manipulated in the same fashion and compared with 28 nonmanipulated V-Loc sutures. Peak force needed to make the suture slip backward in porcine small intestine was determined to be the sliding force. Scanning electron microscopy of the barbs before and after robotic manipulation was also performed. The mean difference in breaking forces for manipulated vs nonmanipulated Maxon sutures was 4.52 N (P=0.004). The mean difference in breaking forces for manipulated vs nonmanipulated V-Loc sutures was 1.30 N (P=0.046). The manipulated V-Loc group demonstrated a lower peak sliding force compared with the nonmanipulated group (0.76 vs 0.88 N, P=0.199). Electron microscopy revealed minor structural damage to the barbs and suture. Tensile strength and peak sliding force of V-Loc suture is decreased by robotic manipulation. This is likely because of structural damage to the suture and barbs. This structural damage, however, is likely not clinically significant.

  1. The Stress Relaxation Process in Sutures Tied with a Surgeon's Knot in a Simulated Biological Environment. (United States)

    Liber-Kneć, Aneta; Łagan, Sylwia


    The exact characteristics of sutures are not only the basis for selecting from among different types of suture, but also provide the necessary information for the design of new surgical sutures. Apart from information relating to the breaking load of a suture reported in pharmacopoeias, the viscoelastic properties of sutures can be an additional selection criterium - one that influences stitching quality, especially when there is a risk of wound dehiscence. The aim of the study was to assess the stress relaxation process for 3 polymeric sutures in an environment simulating the conditions in a living organism and (for comparison) in room conditions. Stress relaxation testing was carried out on 3 polymeric sutures: polypropylene (PP), polydioxanone (PDS) and polyglycolic acid (PGA). To identify the mechanical properties of the sutures, uniaxial tensile tests were conducted according to the Polish Pharmacopoeia. The relaxation test was carried out in room conditions and in the bath simulating a biological environment. The sutures being tested were tied with a surgeon's knot. The PP suture exhibited the greatest stress relaxation (18% of the initial stress in room conditions and 21% of the initial stress in the bath). The PGA suture exhibited the least stress relaxation (approximately 60% of the initial stress in room conditions and 59% of the initial stress in the bath). The PDS suture was tested at a lower strain level and showed stress relaxation similar to the PGA suture (approximately 63% of the initial stress in room conditions and 55% in the bath). Multifilament braided absorbable (PGA) sutures and monofilament absorbable (PDS) sutures had a higher stress relaxation ratio over time than monofilament non-absorbable (PP) sutures. These findings may indicate higher stress maintained over time in PDS and PGA sutures, and thus higher tension at wound edges, sufficient to resist wound dehiscence.

  2. A reusable suture anchor for arthroscopy psychomotor skills training. (United States)

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


    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.

  3. Synchrotron-microcomputed tomography studies of normal and pathological cranial sutures: further insight. (United States)

    Regelsberger, Jan; Schmidt, Tobias; Busse, Björn; Herzen, Julia; Tsokos, Michael; Amling, Michael; Beckmann, Felix


    Both CT and high-frequency ultrasound have been shown to be reliable diagnostic tools used to differentiate normal cranial sutures from suture synostosis. In nonsynostotic plagiocephaly, overlapping of the bony plates and the so-called "sticky suture" is still controversial and is believed to represent a pathological fusion process. Synchrotron-microcomputed tomography (SRmCT) studies were undertaken to determine whether positional head deformities can be assumed to be true suture pathologies. Morphological features and growth development of 6 normal cranial sutures between the ages of 3 and 12 months were analyzed histologically. Additionally 6 pathological sutures, including sagittal synostosis and nonsynostotic plagiocephaly (NSP), were compared with the group of normal sutures by histological and SRmCT studies. Synchrotron-microcomputed tomography is a special synchrotron radiation source with a high photon flux providing a monochromatic x-ray beam with a very high spatial resolution. Morphological characteristics of the different suture types were evaluated and bone density alongside the sutures was measured to compare the osseous structure of the adjacent bony plates of normal and pathological sutures. Histologically jointlike osseous edges of the normal sutures were seen in the 1st month of life and interlocking at the age of approximately 12 months. During this 1st year, bone thickness increases and suture width decreases. The SRmCT studies showed that: 1) sutures and adjacent bones in NSP are comparable to normal sutures in terms of their morphological aspects; 2) bone densities in the adjacent bony plates of NSP and normal sutures are not different; 3) thickening of the diploe with ridging of the bone in sagittal synostosis is associated with significantly higher bone density; 4) synostotic sutures are only partially fused but vary in their extent; and 5) nonfused sections in sagittal synostosis behave like normal sutures without any signs of pathological

  4. Absorbable Polydioxanone (PDS) suture provides fewer wound complications than polyester (ethibond) suture in acute Tendo-Achilles rupture repair

    LENUS (Irish Health Repository)

    Baig, M N


    We prospectively studied acute Achilles tendon rupture in patients over a two 2-year period and reviewed the causes, outcome and complications. There were 53 patients included with acute Achilles rupture with minimum follow up period of 6 months. We compared the outcomes including infection rate and Boyden score between the two groups repaired by Polydioxanone and Polyester respectively. All infected cases had a suture repair using the polyester suture. The difference in the infection rate was highly significant between the 2 groups (p=0.001). All 34 patients (100%) in the PDS group had good \\/ excellent results based on the Boyden clinical assessment. Conversely, only 16 patients 9(68.4%) had good or excellent results IN Polyester repair group. Patients treated with a non- absorbable suture (ethibond) material for repair had a higher incidence infection and worse Boyden scores than the absorbable PDS group.

  5. Achondroplasia with multiple-suture craniosynostosis: a report of a new case of this rare association

    NARCIS (Netherlands)

    Bessenyei, Beáta; Nagy, Andrea; Balogh, Erzsébet; Novák, László; Bognár, László; Knegt, Alida C.; Oláh, Eva


    We report on a female patient with an exceedingly rare combination of achondroplasia and multiple-suture craniosynostosis. Besides the specific features of achondroplasia, synostosis of the metopic, coronal, lambdoid, and squamosal sutures was found. Series of neurosurgical interventions were

  6. [Subluxation of scleral-fixated PC IOL caused by polypropylene suture degradation--case report]. (United States)

    Kanigowska, Krystyna; Grałek, Mirosława; Czarnowska, Elzbieta; Zajaczkowska, Agnieszka


    The purpose of the study is to evaluate factors related to late-onset of lens subluxation in transscleral sutured posterior chamber IOL. We report a child, which required surgical treatment for dislocation of a scleral-sutured PC IOL. 11 years earlier the secondary lens implantation with scleral fixation was performed in 4 years old boy. The first surgical procedure included an anterior victrectomy and suturing a single- piece PMMA IOL under the scleral flaps with a 10-0 polipropylene suture. The second--included explantation of the dislocated lens. Optic and scanning electron microscopy was used to analyze the surface of the explanted remnants of the breakage suture. Microscopic findings indicate that the late suture breakage and subluxation of suture-fixated PC IOL was due to the degradation of polypropylene suture.

  7. Comparison of the cheese-wiring effects among three sutures used in rotator cuff repair. (United States)

    Lambrechts, Mark; Nazari, Behrooz; Dini, Arash; O'Brien, Michael J; Heard, Wendell M R; Savoie, Felix H; You, Zongbing


    The goal of this study was to compare the cheese-wiring effects of three sutures with different coefficients of friction. Sixteen human cadaveric shoulders were dissected to expose the distal supraspinatus and infraspinatus muscle tendons. Three sutures were stitched through the tendons: #2 Orthocord(™) suture (reference #223114, DePuy Mitek, Inc., Raynham, MA), #2 ETHIBOND* EXCEL Suture, and #2 FiberWire(®) suture (FiberWire(®), Arthrex, Naples, FL). The sutures were pulled by cyclic axial forces from 10 to 70 N at 1 Hz for 1000 cycles through a MTS machine. The cut-through distance on the tendon was measured with a digital caliper. The cut-through distance in the supraspinatus tendons (mean ± standard deviation, n = 12) were 2.9 ± 0.6 mm for #2 Orthocord(™) suture, 3.2 ± 1.2 mm for #2 ETHIBOND* suture, and 4.2 ± 1.7 mm for #2 FiberWire(®) suture. The differences were statistically significant analyzing with analysis of variance (P = 0.047) and two-tailed Student's t-test, which showed significance between Orthocord(™) and FiberWire(®) sutures (P = 0.026), but not significant between Orthocord(™) and ETHIBOND* sutures (P = 0.607) or between ETHIBOND* and FiberWire(®) sutures (P = 0.103). The cheese-wiring effect is less in the Orthocord(™) suture than in the FiberWire(®) suture in human cadaveric supraspinatus tendons. Identification of sutures that cause high levels of tendon cheese-wiring after rotator cuff repair can lead to better suture selection.

  8. Reaching state-of-the art requirements for MIM capacitors with a single-layer anodic Al2O3 dielectric and imprinted electrodes (United States)

    Hourdakis, Emmanouel; Nassiopoulou, Androula G.


    Metal-Insulator-Metal (MIM) capacitors with a high capacitance density and low non-linearity coefficient using a single-layer dielectric of barrier-type anodic alumina (Al2O3) and an imprinted bottom Al electrode are presented. Imprinting of the bottom electrode aimed at increasing the capacitor effective surface area by creating a three-dimensional MIM capacitor architecture. The bottom Al electrode was only partly nanopatterned so as to ensure low series resistance of the MIM capacitor. With a 3 nm thick anodic Al2O3 dielectric, the capacitor with the imprinted electrode showed a 280% increase in capacitance density compared to the flat electrode capacitor, reaching a value of 20.5 fF/μm2. On the other hand, with a 30 nm thick anodic Al2O3 layer, the capacitance density was 7.9 fF/μm2 and the non-linearity coefficient was as low as 196 ppm/V2. These values are very close to reaching all requirements of the last International Technology Roadmap for Semiconductors for MIM capacitors [ITRS, for ITRS Roadmap (2013)], and they are achieved by a single-layer dielectric instead of the complicated dielectric stacks of the literature. The obtained results constitute a real progress compared to previously reported results by our group for MIM capacitors using imprinted electrodes.

  9. Copper-vapor-assisted chemical vapor deposition for high-quality and metal-free single-layer graphene on amorphous SiO2 substrate. (United States)

    Kim, Hyungki; Song, Intek; Park, Chibeom; Son, Minhyeok; Hong, Misun; Kim, Youngwook; Kim, Jun Sung; Shin, Hyun-Joon; Baik, Jaeyoon; Choi, Hee Cheul


    We report that high-quality single-layer graphene (SLG) has been successfully synthesized directly on various dielectric substrates including amorphous SiO2/Si by a Cu-vapor-assisted chemical vapor deposition (CVD) process. The Cu vapors produced by the sublimation of Cu foil that is suspended above target substrates without physical contact catalyze the pyrolysis of methane gas and assist nucleation of graphene on the substrates. Raman spectra and mapping images reveal that the graphene formed on a SiO2/Si substrate is almost defect-free and homogeneous single layer. The overall quality of graphene grown by Cu-vapor-assisted CVD is comparable to that of the graphene grown by regular metal-catalyzed CVD on a Cu foil. While Cu vapor induces the nucleation and growth of SLG on an amorphous substrate, the resulting SLG is confirmed to be Cu-free by synchrotron X-ray photoelectron spectroscopy. The SLG grown by Cu-vapor-assisted CVD is fabricated into field effect transistor devices without transfer steps that are generally required when SLG is grown by regular CVD process on metal catalyst substrates. This method has overcome two important hurdles previously present when the catalyst-free CVD process is used for the growth of SLG on fused quartz and hexagonal boron nitride substrates, that is, high degree of structural defects and limited size of resulting graphene, respectively.

  10. Phase diagram and electronic indication of high-temperature superconductivity at 65 K in single-layer FeSe films. (United States)

    He, Shaolong; He, Junfeng; Zhang, Wenhao; Zhao, Lin; Liu, Defa; Liu, Xu; Mou, Daixiang; Ou, Yun-Bo; Wang, Qing-Yan; Li, Zhi; Wang, Lili; Peng, Yingying; Liu, Yan; Chen, Chaoyu; Yu, Li; Liu, Guodong; Dong, Xiaoli; Zhang, Jun; Chen, Chuangtian; Xu, Zuyan; Chen, Xi; Ma, Xucun; Xue, Qikun; Zhou, X J


    The recent discovery of possible high-temperature superconductivity in single-layer FeSe films has generated significant experimental and theoretical interest. In both the cuprate and the iron-based high-temperature superconductors, superconductivity is induced by doping charge carriers into the parent compound to suppress the antiferromagnetic state. It is therefore important to establish whether the superconductivity observed in the single-layer sheets of FeSe--the essential building blocks of the Fe-based superconductors--is realized by undergoing a similar transition. Here we report the phase diagram for an FeSe monolayer grown on a SrTiO3 substrate, by tuning the charge carrier concentration over a wide range through an extensive annealing procedure. We identify two distinct phases that compete during the annealing process: the electronic structure of the phase at low doping (N phase) bears a clear resemblance to the antiferromagnetic parent compound of the Fe-based superconductors, whereas the superconducting phase (S phase) emerges with the increase in doping and the suppression of the N phase. By optimizing the carrier concentration, we observe strong indications of superconductivity with a transition temperature of 65±5 K. The wide tunability of the system across different phases makes the FeSe monolayer ideal for investigating not only the physics of superconductivity, but also for studying novel quantum phenomena more generally.

  11. Comparison of Single-Layer and Double-Layer Anti-Reflection Coatings Using Laser-Induced Damage Threshold and Photothermal Common-Path Interferometry

    Directory of Open Access Journals (Sweden)

    Caspar Clark


    Full Text Available The dielectric thin-film coating on high-power optical components is often the weakest region and will fail at elevated optical fluences. A comparison of single-layer coatings of ZrO2, LiF, Ta2O5, SiN, and SiO2 along with anti-reflection (AR coatings optimized at 1064 nm comprised of ZrO2 and Ta2O5 was made, and the results of photothermal common-path interferometry (PCI and a laser-induced damage threshold (LIDT are presented here. The coatings were grown by radio frequency (RF sputtering, pulsed direct-current (DC sputtering, ion-assisted electron beam evaporation (IAD, and thermal evaporation. Test regimes for LIDT used pulse durations of 9.6 ns at 100 Hz for 1000-on-1 and 1-on-1 regimes at 1064 nm for single-layer and AR coatings, and 20 ns at 20 Hz for a 200-on-1 regime to compare the //ZrO2/SiO2 AR coating.

  12. Investigation of the single layer model of GPS ionospheric data processing using IRI-90 and the attached diffusive equilibrium model of plasmaspheric electron density

    Directory of Open Access Journals (Sweden)

    L. Bànyai


    Full Text Available The single layer model of GPS ionospheric data processing is compared with the International Reference Ionosphere í 1990 and the attached Diffusive Equilibrium model of Plasmasphere (IRI-90+DEP which proved to be a good supplement to GPS data processing. These models can be used to estimate the single layer height and to improve the mapping function in day-time. The code delays estimated from IRI-90+DEP models are compared with GPS measurements carried out by TurboRogue receiver. These models can be used to estimate the preliminary receiver biases especially in the case of cross-correlation tracking mode. The practical drawback of the IRI-90 model is the sharp discontinuity of the ion components during sunset and sunrise at an elevation of 1000 km, because it also causes a sharp discontinuity in the TEC values computed from the DEP model. The GPS data may be a good source to improve the topside region of the IRI model estimating smooth TEC transition before and after sunrise in the plasmasphere.

  13. Polymeric Medical Sutures: An Exploration of Polymers and Green Chemistry (United States)

    Knutson, Cassandra M.; Schneiderman, Deborah K.; Yu, Ming; Javner, Cassidy H.; Distefano, Mark D.; Wissinger, Jane E.


    With new K-12 national science standards emerging, there is an increased need for experiments that integrate engineering into the context of society. Here we describe a chemistry experiment that combines science and engineering principles while introducing basic polymer and green chemistry concepts. Using medical sutures as a platform for…

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

    Czech Academy of Sciences Publication Activity Database

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


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

  15. Comparative study between purse–string suture and peritoneal ...

    African Journals Online (AJOL)

    Comparative study between purse–string suture and peritoneal disconnection with ligation techniques in the laparoscopic repair of inguinal hernia in infants and ... The main outcome measurement was recurrence, and secondary outcome measurements were operative time, hospital stay, intraoperative complications, ...

  16. Sterilization effects on tensile strength of non-conventional suture ...

    African Journals Online (AJOL)

    An experiment was carried out to determine the tensile strength of embroidery, braiding, cobbler's thread and nylon mono-filament fishing line (NMFL) use as non-conventional suture material. Their tensile strength were determined pre- sterilization using various calibrated weights (50gm, 100gm, 500gm).

  17. Outcome of Strabismus Surgery by Nonadjustable Suture among ...

    African Journals Online (AJOL)


    Mar 6, 2017 ... Outcome of strabismus surgery by nonadjustable suture among adults attending a university hospital of. Saudi Arabia. Niger J Clin Pract 2017;20:335-40. This is an open access article distributed under the terms of the Creative Commons. Attribution-Non Commercial-Share Alike 3.0 License, which allows ...

  18. Outcome of strabismus surgery by nonadjustable suture among ...

    African Journals Online (AJOL)

    Objective: To describe the outcome and safety of surgical treatment of Saudi adult patients with strabismus by nonadjustable suture and to evaluate the prevalence of diplopia and binocularity after strabismus correction. Materials and Methods: Retrospective analysis of medical records of 96 patients above the age of ...

  19. Penile torsion correction by diagonal corporal plication sutures

    Directory of Open Access Journals (Sweden)

    Brent W. Snow


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

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

    Directory of Open Access Journals (Sweden)

    Bhatti S


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

  1. Single-suture scleral fixation of subluxated foldable intraocular lenses. (United States)

    Yarangumeli, Alper; Alp, Mehmet Numan; Kural, Gulcan


    To evaluate the results of single-suture scleral fixation of subluxated foldable intraocular lenses (IOL) in eyes with sufficient residual capsular support. The results of IOL repositioning by single-suture scleral fixation in 6 eyes of 6 patients with IOL subluxation were included. All subluxated IOLs were single-piece hydrophilic acrylic. Subluxation resulted from posterior capsule tears in 3 eyes, zonular dialyses in 2 eyes, and zonular dialysis with a capsulorhexis tear in 1 eye. A similar technique was used in all eyes in which one haptic was externalized through a superior clear corneal incision and tied with a Pair-PAK 10-0 polypropylene suture, and was finally retracted and fixated behind the iris close to the ciliary sulcus at the 12:00 meridian. All patients were followed up for at least 6 months. Best-corrected visual acuities ranged between finger counting and 20/70 (mean logMAR 1.02±0.64) preoperatively, and between 20/100 and 20/20 (mean logMAR 0.22±0.26) at the final postoperative visit. All IOLs remained centered and no significant postoperative complications were encountered except for an IOL tilt which resulted in a considerable oblique astigmatism in one eye. Subluxated foldable IOLs may safely be repositioned and secured with a single scleral fixation suture in selected cases with adequate amount of capsular remnants.

  2. Omental pedicle transposition and suture repair of peripheral nerve ...

    African Journals Online (AJOL)

    Abu wael

    immediately under a dissecting microscope (Kruss, Germany). Six equidistant epineurial simple interrupted sutures were ... strong, and muscle mass atrophy graded as severe, moderate, mild or normal. Sensory functions evaluation .... could secrete analgesic substances such as opioids, neurotransmitters including gamma ...

  3. non absorbable sutures in the urinary bladder resulting

    African Journals Online (AJOL)

    The vesical calculus. Urol Clin North AM. 2000, 27:333-346. 3. Evans JW, Chapple CR, Ralph DJ, Millory EJ: Bladder calculus formation as a complication of the Stamey procedure. Br J Urol 1990,. 65:580-582. 4. Sheng-Tsun Su, He-Fu Haung, Shu-Fen. Chang. Encrusted Bladder stone on Non- absorbable sutures after a ...

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

    Directory of Open Access Journals (Sweden)

    Alex Elías-Zúñiga


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

  5. Healing of the suture line in the irradiated small intestine

    International Nuclear Information System (INIS)

    Da Costa, S.A.


    With the help of data from literature the author goes more deeply into the aetiology, treatment and possible prevention of lesions of the small intestine related to preceding irradiation. In a clinical retrospective study at twenty patients who, after irradiation of the abdominal and pelvic areas, have been submitted to abdominal surgery, the relation is studied between predistion factors for gastrointestinal complications after irradiation, the surgeries applied in case of small-intestine problems and postoperative complications. The third part of the thesis covers an experimental part in which the healing process of suture line in the terminal ileum has been studied after resection and reanastomosis in previously irradiated bowel of the rat. It was investigated whether differences occurred in the healing process of suture line after various periods - 4, 10 and 40 weeks, after irradiation. Also comparison took place with a control group which underwent a similar procedure with the exception of the radiation treatment, which was simulated in this group. In a second experiment it was investigated if the healing process of suture line depends on the type of anastomosis. An end-to-end anastomosis was chosen versus side-to-side anastomosis. Also in this experiment an irradiated group was compared with a control group. Furthermore a method was developed for performing micro-angiographies of the rat intestine in order to demonstrate obliteration of blood vessels in irradiated intestine and to assess neovascularization in the intestinal wall at the suture line. (author). 84 refs.; 18 figs.; 27 tabs

  6. Comparison of Subcuticular Suture Materials in Cesarean Skin Closure

    Directory of Open Access Journals (Sweden)

    Pınar Solmaz Hasdemir


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

  7. Punctal Occlusion with Prolene Suture Material in the Patients with ...

    African Journals Online (AJOL)

    polypropene, a synthetic linear polyolefin. This suture is pigment blue to enhance visibility. Prolene is neither absorbable nor elastic [Figure 9]. The size (such as the diameter of the cross-section and the thickness) of the Prolene material as measured with an optical microscope (Nikon Eclipse Me600) and a digital calliper.

  8. Nonsuturing or Skin Adhesives versus Suturing of the Perineal Skin After Childbirth: A Systematic Review

    NARCIS (Netherlands)

    Seijmonsbergen-Schermers, A.E.; Sahami, S.; Lucas, C.; de Jonge, A.


    Background: Suturing of perineal trauma after childbirth can cause problems such as pain, discomfort because of tight sutures, the need for suture removal, and dyspareunia. It is unclear whether leaving the perineal skin unsutured or using skin adhesives might prevent these problems. Methods:

  9. Nonsuturing or Skin Adhesives versus Suturing of the Perineal Skin After Childbirth: A Systematic Review

    NARCIS (Netherlands)

    Seijmonsbergen-Schermers, Anna E.; Sahami, Saloomeh; Lucas, Cees; Jonge, Ank de


    Suturing of perineal trauma after childbirth can cause problems such as pain, discomfort because of tight sutures, the need for suture removal, and dyspareunia. It is unclear whether leaving the perineal skin unsutured or using skin adhesives might prevent these problems. CENTRAL, MEDLINE, EMBASE,


    NARCIS (Netherlands)



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

  11. Microbial adherence on various intraoral suture materials in patients undergoing dental surgery. (United States)

    Banche, Giuliana; Roana, Janira; Mandras, Narcisa; Amasio, Mario; Gallesio, Cesare; Allizond, Valeria; Angeretti, Alessandra; Tullio, Vivian; Cuffini, Anna Maria


    Sutures used in oral surgery should avoid or limit bacterial adhesion and proliferation to those parts exposed to oral fluids. Hence, microbial colonization on various intraoral suture materials from patients undergoing dental surgery was compared. During dentoalveolar surgery, various suture materials were used in 60 patients, who were randomly divided into 5 groups of 12. In each group, silk was placed intraorally in association with a different type of suture (ie, Supramid, Synthofil, Ethibond Excel, Ti-cron, Monocryl) at the same site to compare microbial colonization intraindividually. Eight days postoperatively, the sutures were removed, and adhered micro-organisms were isolated, counted, and identified through enzymatic activities and fermentation of sugars. In all 60 patients, silk sutures exhibited the smallest affinity toward the adhesion of bacteria compared with considerable proliferation with nonresorbable multifilament sutures (Supramid, Synthofil, Ethibond Excel, Ti-cron). On the contrary, the microbial load was significantly lower when absorbable monofilament Monocryl was used. A greater quantity of bacteria was found on nonresorbable sutures than on absorbable ones, and nearly 2 times more facultative anaerobic bacteria were isolated in total. Our results show that bacteria adhere with different affinity to various types of suture materials. Absorbable silk and Monocryl exhibited the smallest number of adherent bacteria. Colonization by pathogens on sutures leads to the recommendation that sutures should be removed as early as possible after surgery is performed, to eliminate or to limit the reservoir for oral pathogens. This recommendation is dependent on whether the suture is absorbable.

  12. Multilevel treatment of moderate and severe obstructive sleep apnea with bone-anchored pharyngeal suspension sutures. (United States)

    Berg, Eric E; Bunge, Frederick; Delgaudio, John M


    Success rates for the surgical treatment of obstructive sleep apnea (OSA) vary, with phase I surgical success ranging from 40 to 75%. Pharyngeal suspension suture procedures are minimally invasive techniques with a reported efficacy of 20 to 78%. We conducted a study to evaluate the effectiveness of pharyngeal suspension suture procedures in conjunction with uvulopalatopharyngoplasty (UPPP) as a multilevel treatment for OSA. We retrospectively reviewed the charts of 30 adults-22 men and 8 women, with a mean age of 49 years and a mean BMI of 30.6-who were treated at a tertiary care academic medical center and a private otolaryngology practice. All patients had moderate or severe OSA, and all had failed continuous positive airway pressure therapy. Of this group, 20 patients underwent tongue base and hyoid suspension (TBHS) and 10 underwent tongue base suspension (TBS) alone; 23 patients had undergone concurrent or previous UPPP, 13 in the TBHS group and all 10 in the TBS group. Polysomnography was performed an average of 3.9 months postoperatively. Surgical success was defined as a reduction in respiratory distress index (RDI) of more than 50% and a postoperative RDI of 20 or less. The overall surgical success rate was 63% (19/30). In the surgical success group, the mean RDI fell from 44.6 to 9.4 (p breaks, and 1 dislodged screw. We conclude that pharyngeal suspension suture procedures as part of the multilevel treatment of moderate and severe OSA yields better outcomes than conventional surgical treatments with the added benefit of being minimally invasive.

  13. Gondwana and Cathaysian blocks, palaeotethys sutures and cenozoic tectonics in South-east Asia (United States)

    Hutchison, Charles S.


    The Triassic Indosinian Orogeny followed extinction of the Palaeotethys Ocean resulting in suturing of Gondwana affinity and Cathaysian blocks. The Gondwana affinity Sinoburmalaya block of Peninsular Malaysia, characterized by Carboniferous—Permian mudstones containing glacial dropstones and sparse fauna and flora, is traced extensively into Sumatra. This mudstone facies is flanked on the east by a sandstone-dominated facies and by carbonate localized in the Kinta Valley. The muddy and sandy facies both begin with a basal Carboniferous condensed red bed sequence, which unconformably overlies the older formations of Sinoburmalaya. Both facies also demonstrate a Late Permian conformable transition into overlying limestone. The Cathaysian block of East Malaya is characterized by Late Permian Gigantopteris flora and fusulinid limestones associated with andesitic volcanism. It is similar but not identical to the West Sumatra Carboniferous—Permian block, characterized by Early Permian volcanism, fusulinid limestones and early Cathaysian Jambi flora. The South to SSE trending central Peninsular Malaysian Triassic orogenic belt swings south-east from Singapore to Bangka, then east to Billiton. The Palaeotethys suture (Bentong—Raub Line) forms the western margin of this belt and is therefore unlikely to continue south along the Palaeogene Bengkalis Graben, which transects the north-west—south-east orogenic fabric of Sumatra. The oroclinal bending of the Indosinian Orogen, from a north-west—south-east grain in Sumatra to a northerly grain through Peninsular Malaysia, is attributed to the Palaeocene collision of India and its subsequent indentation into Eurasia. The bending was accomplished by clockwise rotation and right-lateral shear parallel to the orogenic grain. The Mesozoic Palaeotethyan sutures were transformed into Palaeocene and younger shear zones. The outer zones of the orocline experienced pull apart tectonics (Andaman Sea and Sumatra basins) while the

  14. Horizontal suture placement influences meniscal repair fixation strength. (United States)

    Kocabey, Yavuz; Taser, Omer; Nyland, John; Ince, Haluk; Sahin, Feyzi; Sunbuloglu, Emin; Baysal, Gokhan


    This in vitro biomechanical study investigated the influence of horizontal suture placement distance from the medial meniscal lesion repair site on fixation characteristics during submaximal cyclic and load to failure test conditions. Eighteen cadaveric (20-45 years of age) medial menisci with intact joint capsules were harvested within 24-48 h after death and divided into two groups of 9 specimens each for biomechanical testing. A 2.0-cm-long antero-posterior vertical longitudinal lesion was created with a #15 scalpel 2.0-3.0 mm from the outer edge of each meniscus. Menisci were repaired using #2-0 suture material with two horizontal suture loops placed either 1.0 mm (Group 1) or 3.0 mm (Group 2) from the lesion site. Following repair, the lesion was extended completely through the meniscal horns so that no tissue secured the repair, only the two horizontal suture loops representing a "worst-case" testing scenario. Following repair, specimens were placed in a servo hydraulic device using a pair of 1.2-mm-diameter steel wire loops and underwent submaximal cyclic loading between 5 and 50 N (1 Hz) for 500 cycles prior to load to failure testing (5 mm/min crosshead speed, 20 Hz data collection). An alpha level of P lesion displayed superior repair fixation than sutures placed closer to the lesion. The superior biomechanical meniscal repair fixation provided by capturing greater tissue volume may enable safe earlier participation in functional exercise activities. Studies are needed to verify these findings in vivo.

  15. The Incidence and Topographic Distribution of Sutures Including Wormian Bones in Human Skulls. (United States)

    Cirpan, Sibel; Aksu, Funda; Mas, Nuket


    The Wormian Bones are accessory bones located within the cranial sutures and fontanelles. The present article examines the incidence of Wormian Bones and compares the number and topographic distribution between the sutures including Wormian Bones in skulls of West Anatolian Population. One hundred fifty crania were examined. The parameters evaluated in the present study were as follows: the rate of skulls including Wormian Bones; the topographic distribution and frequencies of the sutures including Wormian Bones; the number of these sutures for each skull; the name and number of sutures that were bilaterally and symmetrically located on the right and left side of skull (paired sutures) and which coincidentally had Wormian Bones for each skull; the differences of frequencies between the paired sutures including Wormian Bones. The rate of skulls including Wormian Bones was determined as 59.3%. The maximum and minimum numbers of sutures, including Wormian Bones, were 6 in 1 skull and 1 in each of 30 skulls, respectively. The maximum and minimum rates of sutures that had Wormian Bones were found in left lambdoid 40.7% and right occipitomastoid 1.3% sutures, respectively. There was only a significant difference between the rate of right and left squamous sutures (P = 0.04). Forty-five skulls were including 55 pairs of bilaterally and symmetrically located sutures that coincidentally had Wormian Bones in each pair. Each of 35 skulls had 1 pair of sutures including Wormian Bones and each of 10 skulls had 2 pairs. In the present study, the rate of Wormian Bones was determined as 59.3% in West Anatolian Population. This incidence rate is considerably lower than the other reports, and it may be as a result of racial variations. These divergent bones were more frequently found in left lambdoid sutures (40.7%) and less frequently in right occipitomastoid sutures (1.3%). This study may guide the investigators dealing with the neurosurgery, orthopedy, radiology, anatomy, and

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

    Directory of Open Access Journals (Sweden)

    Morris C Phillip


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

  17. An implantable sensor device measuring suture tension dynamics: results of developmental and experimental work. (United States)

    Schachtrupp, A; Wetter, O; Höer, J


    Knowledge about suture tension dynamics after laparotomy closure is limited due to the lack of adequate measurement tools. As a consequence, a miniaturized implantable sensor and data logger were developed and applied experimentally in a porcine model to measure suture tension dynamics after laparotomy closure. We developed an implantable device (6 × 3 × 1 mm) fitted with silicon strain gauges and an implantable data logger allowing long-term registration. In nine domestic pigs, sensors and loggers were implanted along the suture closing a median laparotomy registering suture tension over a period of 23 h. Fascial closure was achieved by a mean suture tension of 1.07 N. After 30 minutes, suture tension was reduced to 0.81N (-24.3 %, p = 0.0003). After 12 h, tension showed a further decrease to 0.69 N (-35.5 %, n.s.), after 23 h mean suture tension reached 0.56 N, (-47.7 %, p = 0.014). The aim to develop an implantable miniaturized sensor device registering long-term suture tension dynamics was achieved. The use in the animal experiment was feasible and safe. We observed a loss of almost 50 % of suture tension 23 h after fascial closure. This could mean that up to 50 % of initial suture tension may be an unnecessary surplus not contributing to tissue stability but to the risk of suture failure.

  18. R&D for a single-layer $Nb_{3}Sn$ common coil dipole using the react-and-wind fabrication technique

    CERN Document Server

    Ambrosio, G; Barzi, E; Bauer, P; Chichili, D R; Ewald, K D; Fehér, S; Imbasciati, L; Kashikhin, V V; Limon, P J; Litvinenko, L; Novitski, I; Rey, J M; Scanlan, R M; Yadav, S; Yamada, R; Zlobin, A V


    A dipole magnet based on the common coil design, using prereacted Nb /sub 3/Sn superconductor, is under development at Fermilab, for a future Very Large Hadron Collider. This magnet has some innovative design and technological features such as single layer coils, a 22 mm wide 60-strand Rutherford type cable and stainless steel collars reinforced by horizontal bridges inserted between coil blocks. Both left and right coils are wound simultaneously into the collar structure and then impregnated with epoxy. In order to optimize the design and fabrication techniques an R&D program is underway. The production of cables with the required characteristics was shown possible. Collar laminations were produced, assembled and tested in order to check the effectiveness of the bridges and the validity of the mechanical design. A mechanical model consisting in a 165 mm long section of the magnet straight section was assembled and tested. This paper summarizes the status of the program, and reports the results of fabrica...

  19. NMR studies of Borrelia burgdorferi OspA, a 28 kDa protein containing a single-layer {beta}-sheet

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Thuy-Nga; Koide, Shohei


    The crystal structure of outer surface protein A (OspA) from Borrelia burgdorferi contains a single-layer {beta}-sheet connecting the N- and C-terminal globular domains. The central {beta}-sheet consists largely of polar amino acids and it is solvent-exposed on both faces, which so far appears to be unique among known protein structures. We have accomplished nearly complete backbone H, C and N and C{sup ;}/H{sup {beta}} assignments of OspA (28 kDa) using standard triple resonance techniques without perdeuteration. This was made possible by recording spectra at a high temperature (45 {sup o}C ). The chemical shift index and {sup 15}N T{sub 1}/T{sub 2} ratios show that both the secondary structure and the global conformation of OspA in solution are similar to the crystal structure, suggesting that the unique central {beta}-sheet is fairly rigid.

  20. Remote N2 plasma treatment to deposit ultrathin high-k dielectric as tunneling contact layer for single-layer MoS2 MOSFET (United States)

    Qian, Qingkai; Zhang, Zhaofu; Hua, Mengyuan; Wei, Jin; Lei, Jiacheng; Chen, Kevin J.


    Remote N2 plasma treatment is explored as a surface functionalization technique to deposit ultrathin high-k dielectric on single-layer MoS2. The ultrathin dielectric is used as a tunneling contact layer, which also serves as an interfacial layer below the gate region for fabricating top-gate MoS2 metal–oxide–semiconductor field-effect transistors (MOSFETs). The fabricated devices exhibited small hysteresis and mobility as high as 14 cm2·V‑1·s‑1. The contact resistance was significantly reduced, which resulted in the increase of drain current from 20 to 56 µA/µm. The contact resistance reduction can be attributed to the alleviated metal–MoS2 interface reaction and the preserved conductivity of MoS2 below the source/drain metal contact.

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

    Directory of Open Access Journals (Sweden)

    Fernandes MA


    Full Text Available Marcos AP Fernandes,1 Bruno MT Pereira,2 Sandra M Guimarães,1 Aline Paganelli,3 Carlos Manoel CT Pereira,1 Claudio Sergio Batista4 1Institute of Obesity and Advanced Video Laparoscopic Surgery of Petropolis, Rio de Janeiro, Brazil; 2Division of Trauma, University of Campinas, São Paulo, Brazil; 3Laboratório de Patologia Micron Cell Diagnóstico, Rio de Janeiro, Brazil; 4Department of Gynecology and Obstetrics, Faculty of Medicine of Petropolis, Rio de Janeiro, Brazil Context and objective: Variations in the ability of surgeons served as motivation for the development of devices that, overcoming individual differences, allow the techniques to be properly performed, and of which the end result was the best possible. Every technique must be reproduced reliably by the majority of surgeons for their results to be adopted and recognized as effective. The aim of this study was to compare the results, from the point of view of anatomic pathology, of manual sutures versus mechanical sutures using different models of linear mechanical staplers, in the procedure of gastroenteroanastomosis and enteroanastomosis in swine. Methods: Thirty-six healthy, adult, male Sus scrofa domesticus pigs, weighing between 20.7 and 25.5 kg, were used. The swine were randomly divided into four groups of nine pigs, according to the type of suture employed: group A, manual suture with Polysorb® 3-0 wire; group B, 80-shear linear stapler (Covidien® Gia 8038-S; group C, 75-shear linear stapler (Ethicon® Tlc 75; and group D, 75-shear linear stapler (Resource® Yq 75-3. A temporal study was established on the seventh postoperative day for histopathological analysis, and the degree of inflammation, fibrosis, and newly formed vessels, as well as the presence or absence of granulation tissue, foreign body granuloma, and necrosis were all evaluated qualitatively and semiquantitatively. The results were analyzed statistically. Results: Observations during the histopathological

  2. Syneture stainless STEEL suture. A collective review of its performance in surgical wound closure. (United States)

    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


    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

  3. Self-directed practice schedule enhances learning of suturing skills. (United States)

    Safir, Oleg; Williams, Camille K; Dubrowski, Adam; Backstein, David; Carnahan, Heather


    Most preoperative surgical training programs experience challenges with the availability of expert surgeons to teach trainees. Some research suggests that trainees may benefit from being allowed to actively shape their learning environments, which could alleviate some of the time and resource pressures in surgical training. The purpose of this study was to investigate the effects of self-directed or prescribed practice schedules (random or blocked) on learning suturing skills. Participants watched an instructional video for simple interrupted, vertical mattress and horizontal mattress suturing then completed a pretest to assess baseline skills. Participants were assigned to 1 of 4 practice groups: self-directed practice schedule, prescribed blocked practice schedule, prescribed random practice schedule or matched to the self-directed group (control). Practice of the skill was followed by a delayed (1 h) posttest. Improvement from pretest to posttest was determined based on differences in performance time and expert-based assessments. Analyses revealed a significant effect of group for difference in performance time of the simple interrupted suture. Random practice did not show the expected advantage for skill learning, but there was an advantage of self-directed practice. Self-directed practice schedules may be desirable for optimal learning of simple technical skills, even when expert instruction is available. Instructors must also take into account the interaction between task difficulty and conditions of practice to develop ideal training environments.

  4. Intraoperative adjustable suture surgery for bilateral superior oblique palsy. (United States)

    Ohtsuki, H; Hasebe, S; Hanabusa, K; Fujimoto, Y; Furuse, T


    The modified Harada-Ito procedure has been reported to be an effective treatment for correction of cyclotorsion in bilateral superior oblique palsy. However, there are no reports regarding its use in intraoperative adjustable suture surgery. The authors performed a retrospective study of 12 patients with traumatic bilateral superior oblique palsy who were classified as having either symmetric or asymmetric palsy according to the symmetry of the alternate hyperdeviation on side gazes. Cyclotorsion and vertical and horizontal deviation in the nine diagnostic positions were measured preoperatively and postoperatively. Of the 12 patients, 6 were determined to have symmetric palsy and 6 asymmetric palsy. Intraoperative adjustable suture surgery with the modified Harada-Ito procedure was performed bilaterally in the six patients with symmetric palsy and unilaterally in those with asymmetric palsy. The median measured value of extorsion in the primary position was reduced from 14.5 degrees to 2.5 degrees in patients with symmetric palsy and from 9.5 degrees to 2.0 degrees in those with asymmetric palsy. In downgaze, some degree of residual extorsion remained, and there was no significant change in esodeviation after surgery. In five patients with symmetric palsy and in all of those with asymmetric palsy, normal single binocular vision in the primary position but did not that in downgaze was restored after surgery. Intraoperative adjustable suture surgery is an effective treatment in correcting torsion, but may not be as effective for esodeviation in downgaze.

  5. The impact of different peripheral suture techniques on the biomechanical stability in flexor tendon repair. (United States)

    Wieskötter, B; Herbort, M; Langer, M; Raschke, M J; Wähnert, D


    Flexor tendon repair consists of circumferential peripheral sutures in combination with core sutures to avoid fraying and reduces the exposure of suture material on tendon surface. The peripheral suture adds up to a tenfold increase of the biomechanical stability compared to the core suture alone. The purpose of our study was to determine the most favourable peripheral repair technique for tendon repair. Seventy-two porcine flexor tendons underwent standardized tenotomy and repair using one of the following six methods (n = 12): simple-running (SR), simple-locking (SL), Halsted-mattress (HM), lin-locking (LL), Lembert-mattress (LM), and Silfverskiöld cross-stich (SCS) suture technique. The SL- suture was placed 2 mm; the HM, LM, SC, and LL suture were placed 5 mm from the tendon gap. The SR suture was placed 1, 2, and 3 mm from tendon ends; no additional core suture was applied. For cyclic testing (1000 cycles), elongation was calculated; for load to failure construct stiffness, yield load and maximum load were determined. The mean cyclic elongation for all tested suture techniques was less than 2 mm; there was no significant difference between the groups regarding elongation as well as yield load. The HM, LM, SCS, and LL suture techniques presented significantly higher maximum loads compared to the SR- and SL-sutures. The 3 mm SR showed significantly higher maximum loads compared to the 2 and 1 mm SR. Beside the distance from tendon gap, the type of linkage of the suture material across and beneath the epitendineum is important for biomechanical stability. Simple-running suture is easy to use, even with a slight increase of the distance from tendon gap significantly increases biomechanical strength. For future repairs of flexor tendon injuries, 3 mm stitch length is highly recommended for simple peripheral suture, while the Halsted-mattress suture unites the most important qualities: biomechanically strong, most part of suture material placed

  6. Skull morphometry and vault sutures of Myrmecophaga tridactyla and Tamandua tetradactyla

    Directory of Open Access Journals (Sweden)

    Camila M. de S. Hossotani


    Full Text Available ABSTRACT This study aimed to examine the relationship between skull size and the level of cranial vault suture closure. A total of 50 Myrmecophaga tridactyla Linnaeus, 1758 and 178 Tamandua tetradactyla Linnaeus, 1758 skulls were analyzed in relation to 18 skull dimensions. The skulls were grouped into three levels of suture closure: no sutures closed (level 0, one or all the fallowing sutures closed: interfrontalis, sagitalis and coronalis (level 1 and all sutures closed (level 2. The results indicated that among the 18 variables measured, 17 showed significant differences (p ≤ 0.01 between level 0 and level 1 skulls of T. tetradactyla; as well as between level 0 and level 1, and level 0 and level 2 skulls of M. tridactyla. M. tridactyla level 1 and level 2 had no significant difference among any of the 18 dimensions. The foramen magnum height in both species showed no significant difference (p > 0.05 among any suture categories. In principle, suture closure level and cranial dimensions are related. The specimens with larger cranial dimensions showed greater number of cranial vault sutures closed for both species of anteaters. Tamandua tetradactyla and M. tridactyla specimens with none of the cranial vault suture closed have a foramen magnum height similar to those with cranial vault suture closed.

  7. A National Survey of Undergraduate Suture and Local Anesthetic Training in the United Kingdom. (United States)

    Rufai, Sohaib R; Holland, Luke C; Dimovska, Eleonora O F; Bing Chuo, Cher; Tilley, Simon; Ellis, Harold


    Suturing is a skill expected to be attained by all medical students on graduation, according to the General Medical Council's (GMC) Tomorrow's Doctors. There are no GMC recommendations for the amount of suture training required at medical school nor the level of competence to be achieved. This study examines the state of undergraduate suture training by surveying a sample of medical students across the United Kingdom. We distributed a survey to 17 medical schools to be completed by undergraduates who have undergone curricular suture training. The survey included questions relating to career intention, hours of curricular suture training, hours of additional paid training, confidence in performing various suture techniques and knowledge of their indications. We also asked about the students' perceived proficiency at injecting local anesthetic and their overall opinion of medical school suture training. We received responses from 705 medical students at 16 UK medical schools. A total of 607 (86.1%) medical students had completed their scheduled curricular suture training. Among them, 526 (86.5%) students reported inadequate suture training in medical school and 133 (21.9%) students had paid for additional training. Results for all competence markers were significantly lower than the required GMC standards (p Students who had paid for additional training were significantly more confident across all areas examined (p students surveyed. These findings suggest that medical schools should provide more opportunities for students to develop their suturing skills to achieve the GMC standard. Copyright © 2015. Published by Elsevier Inc.

  8. Optimal suture anchor direction in arthroscopic lateral ankle ligament repair. (United States)

    Yoshimura, Ichiro; Hagio, Tomonobu; Noda, Masahiro; Kanazawa, Kazuki; Minokawa, So; Yamamoto, Takuaki


    In this study, the distance between the insertion point of the suture anchors and posterior surface of the fibula during arthroscopic lateral ankle ligament repair was investigated on computed tomography (CT) images. The hypothesis of this study was that there is an optimal insertional direction of the suture anchor to avoid anchor-related complications. One hundred eleven ankles of 98 patients who had undergone three-dimensional CT scans for foot or ankle disorders without deformity of the fibula were assessed (59 males, 52 females; median age 25.5 years; age range 12-78 years). The shortest distance from the insertion point of the suture anchor to the deepest point of the fossa/top of the convex aspect of the fibula was measured on the axial plane, tilting from the longitudinal axis of the fibula at 90°, 75°, 60°, and 45°. The distance from the insertion point of the suture anchor to the posterior surface of the fibula was also measured in a direction parallel to the sagittal plane of the lateral surface of the talus on the axial plane, tilting from the longitudinal axis of the fibula at 90°, 75°, 60°, and 45°. The posterior fossa was observed in all cases on the 90° and 75° images. The distance from the insertion point to the posterior surface of the fibula in the parallel direction was 15.0 ± 3.4 mm at 90°, 17.5 ± 3.2 mm at 75°, 21.7 ± 3.3 mm at 60°, and 25.7 ± 3.6 mm at 45°. The posterior points in the parallel direction were located on the posterior fossa in 36.0% of cases at 90°, in 12.6% at 75°, and in 0.0% at 60° and 45°. The suture anchor should be directed from anterior to posterior at an angle of <45° to the longitudinal axis of the fibula, parallel to the lateral surface of the talus, to avoid passing through the fibula. Cohort study, Level III.

  9. A simple suture-retrieval device for the placement of u-stitches during laparoscopic gastrostomy. (United States)

    Mattei, Peter


    During minimally invasive operations, it is sometimes necessary to retrieve the end of a suture or a suture needle and bring it out through the abdominal wall. Using a standard needle and a length of suture, we have developed a simple device that allows the retrieval of a suture end during minimally invasive operations that require the placement of U-or stay stitches. The author has used the device described during more than 100 laparoscopic gastrostomy placement procedures and other operations involving the placement of U- or stay stitches with excellent results and no complications. Using a beveled hollow-bore needle and a loop of polypropylene suture, one can construct a simple device that allows the retrieval of a suture from within a body cavity during minimally invasive surgery, making the placement of U- and stay stitches easier and more precise.

  10. Intraspecific variation of the interparietal suture closure in Siberian roe deer Capreolus pygargus from Jeju Island. (United States)

    Oh, Jinwoo; Oh, Hong-Shik; Kimura, Junpei; Koyabu, Daisuke


    The sequence of cranial suture closure among cervids is reported to be generally species-specific and highly conservative within species. On the other hand, it is known that intraspecific variation often exists to some extent in other mammalian taxa. Here we studied the cranial suture closures of Capreolus pygargus from Jeju Island and compared it with other cervid species. We found that the timing of the interparietal suture closure is highly variable within C. pygargus. Capreolus capreolus similarly shows intraspecific variation of the interparietal suture closure, whereas other cervid species studied to date do not show any intraspecific variation in the sequence of cranial suture closure. Such high intraspecific variation of the interparietal suture may be a derived character for Capreolus.

  11. Meniscal repair using large diameter horizontal sutures increases fixation strength: an in vitro study. (United States)

    Kocabey, Yavuz; Taşer, Omer; Hapa, Onur; Güçlü, Aycan; Bozdag, Ergun; Sünbüloglu, Emin; Doral, Mahmutnedim


    the purpose of this study was to compare the mechanical characteristics of meniscal repair fixation using horizontal sutures and two different diameter sutures under submaximal cyclic and load to failure test conditions. a 2-cm long anteroposterior vertical longitudinal incision was created in two groups of bovine medial menisci. Lesions were repaired using either #2-0 (Group 1), or #2 (Group 2) Fiberwire suture. Following repair, the lesion was extended through the posterior and anterior meniscal horns so that no tissue secured the repair site. Specimens underwent submaximal cyclic (5-50 N at 1 Hz for 500 cycles) and load to failure testing (5 mm/min crosshead speed) in a servo hydraulic device. Specimen failure mode was verified by the primary investigator. An alpha level of P meniscal tissue. Larger diameter suture provided superior mechanical meniscal fixation. if horizontal suture would be used in meniscal repair, the most suitable larger diameter suture should be used.

  12. Quantitative physical and handling characteristics of novel antibacterial braided silk suture materials. (United States)

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


    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

  13. Enterotomy closure using knotless and barbed suture in laparoscopic upper gastrointestinal surgeries. (United States)

    Bautista, Therese; Shabbir, Asim; Rao, Jaideepraj; So, Jimmy; Kono, Koji; Durai, Pradeep


    Barbed sutures are recently being employed in intracorporeal suturing in various laparoscopic digestive surgeries. The purpose of this paper was to present our initial experience of enterotomy closure with barbed sutures in upper gastrointestinal and bariatric surgeries, and share optimal technique of using such sutures for enterotomy closure. Fifty patients who underwent laparoscopic closure of enterotomies using barbed sutures were identified in two institutions in Singapore from January 2012 to December 2013. Patient demographics, short-term operative outcomes including anastomotic time, onset of diet, hospital stay, and early post-operative complications are reported. In 50 patients a total of 62 anastomotic sites were closed with barbed sutures. The barbed sutures appear to reduce mean anastomotic suturing time of the Roux-en-Y gastrojejunal closure (17.34 vs 44.55 min, p value 0.0001) and jejunojejunal closure (19.46 vs 31.01 min, p value 0.0013) when compared to a subgroup of patients with the same anastomotic sites closed using the standard non-barbed suture. The mean onset to start on diet was 2 ± 1.5 days and mean duration of hospital stay is 7 + 5.3 days. One (1.6%) anastomotic leak was observed day 3 after a gastric bypass in the series. This leak was the result of a technical error due to inappropriate suturing technique. There were no mortalities, other complications or readmission. While applying traction on the suture brings two tissue edges closer, we observed that pushing the tissues toward each other provided more apposition and prevented unnecessary tearing of tissues that could potentially result in complications Barbed closure sutures appear to be safe and effective in laparoscopic upper gastrointestinal procedures for closing enterotomies provided appropriate technique is used. The potential benefit is simplifying intracorporeal enterotomy closure.

  14. Effects of suture position on left ventricular fluid mechanics under mitral valve edge-to-edge repair. (United States)

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


    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.

  15. Nonvolatile ferroelectric memory based on PbTiO3 gated single-layer MoS2 field-effect transistor (United States)

    Shin, Hyun Wook; Son, Jong Yeog


    We fabricated ferroelectric non-volatile random access memory (FeRAM) based on a field effect transistor (FET) consisting of a monolayer MoS2 channel and a ferroelectric PbTiO3 (PTO) thin film of gate insulator. An epitaxial PTO thin film was deposited on a Nb-doped SrTiO3 (Nb:STO) substrate via pulsed laser deposition. A monolayer MoS2 sheet was exfoliated from a bulk crystal and transferred to the surface of the PTO/Nb:STO. Structural and surface properties of the PTO thin film were characterized by X-ray diffraction and atomic force microscopy, respectively. Raman spectroscopy analysis was performed to identify the single-layer MoS2 sheet on the PTO/Nb:STO. We obtained mobility value (327 cm2/V·s) of the MoS2 channel at room temperature. The MoS2-PTO FeRAM FET showed a wide memory window with 17 kΩ of resistance variation which was attributed to high remnant polarization of the epitaxially grown PTO thin film. According to the fatigue resistance test for the FeRAM FET, however, the resistance states gradually varied during the switching cycles of 109. [Figure not available: see fulltext.

  16. Current induced annealing and electrical characterization of single layer graphene grown by chemical vapor deposition for future interconnects in VLSI circuits

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Neetu, E-mail:, E-mail:; Kumari, Anita; Bhatnagar, P. K.; Mathur, P. C. [Department of Electronic Science, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021 (India); Bhatia, C. S. [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore)


    Single layer graphene (SLG) grown by chemical vapor deposition (CVD) has been investigated for its prospective application as horizontal interconnects in very large scale integrated circuits. However, the major bottleneck for its successful application is its degraded electronic transport properties due to the resist residual trapped in the grain boundaries and on the surface of the polycrystalline CVD graphene during multi-step lithographic processes, leading to increase in its sheet resistance up to 5 MΩ/sq. To overcome this problem, current induced annealing has been employed, which helps to bring down the sheet resistance to 10 kΩ/sq (of the order of its initial value). Moreover, the maximum current density of ∼1.2 × 10{sup 7 }A/cm{sup 2} has been obtained for SLG (1 × 2.5 μm{sup 2}) on SiO{sub 2}/Si substrate, which is about an order higher than that of conventionally used copper interconnects.

  17. R and D for a single-layer Nb3Sn common coil dipole using the react-and-wind fabrication technique

    International Nuclear Information System (INIS)

    Ambrosio, Giorgio


    A dipole magnet based on the common coil design, using prereacted Nb 3 Sn superconductor, is under development at Fermilab, for a future Very Large Hadron Collider. This magnet has some innovative design and technological features such as single layer coils, a 22 mm wide 60-strand Rutherford type cable and stainless steel collars reinforced by horizontal bridges inserted between coil blocks. Both left and right coils are wound simultaneously into the collar structure and then impregnated with epoxy. In order to optimize the design and fabrication techniques an R and D program is underway. The production of cables with the required characteristics was shown possible. Collar laminations were produced, assembled and tested in order to check the effectiveness of the bridges and the validity of the mechanical design. A mechanical model consisting of a 165 mm long section of the magnet straight section was assembled and tested. This paper summarizes the status of the program, and reports the results of fabrication and test of cable, collars and the mechanical model

  18. Ultradispersed and Single-Layered MoS2 Nanoflakes Strongly Coupled with Graphene: An Optimized Structure with High Kinetics for the Hydrogen Evolution Reaction. (United States)

    Huang, Haoliang; Huang, Junying; Liu, Weipeng; Fang, Yueping; Liu, Yingju


    As one of the most promising Pt alternatives for cost-effective hydrogen production, molybdenum disulfide (MoS 2 ), although has been studied extensively to improve its electrocatalytic activity, suffers from scarce active sites, low conductivity, and lack of interaction with substrates. To this end, we anchor ultradispersed and single-layered MoS 2 nanoflakes on graphene sheets via a hybrid intermediate (MoO x -cysteine-graphene oxide), which not only confines the subsequent growth of MoS 2 on the graphene surface but also ensures the intimate interaction between Mo species and graphene at the initial stage. Mo-O-C bond and a possible residual MoO 3-x layer are proposed to comprise the interface bridging the two inherent incompatible phases, MoS 2 and graphene. This strongly coupled structure together with the highly exposed MoS 2 morphology accelerates the electron injection from graphene to the active sites of MoS 2 , and thus the hydrogen evolution reaction (HER) can achieve an overpotential of ∼275 mV at ∼-740 mA cm -2 , and a Pt-like Tafel slope of ∼35 mV dec -1 . Our results shed light on the indispensable role of interfacial interaction within semiconducting material-nanocarbon composites and provide a new insight into the actual activity of MoS 2 toward the HER.

  19. Theoretical analysis of the combined effects of sulfur vacancies and analyte adsorption on the electronic properties of single-layer MoS2 (United States)

    Akdim, Brahim; Pachter, Ruth; Mou, Shin


    We report a first-principles theoretical investigation on the electronic structure and electron transport of defective single-layer (SL) MoS2, as well as of corresponding structures adsorbed with benzyl viologen (BV), which was shown to provide improved performance of a field effect transistor. O2 adsorption was included to gain an understanding of the response upon air-exposure. Following analysis of the structure and stability of sulfur single vacancy and line defects in SL MoS2, we investigated the local transport at the adsorbed sites via a transport model that mimics a scanning tunneling spectroscopy experiment. Distinct current-voltage characteristics were indicated for adsorbed oxygen species at a sulfur vacancy. The electronic structures of defective MoS2 indicated the emergence of impurity states in the bandgap due to sulfur defects and oxygen adsorption. Electron transport calculations for the MoS2 surface with an extended defect in a device setting demonstrated that physisorption of BV enhances the output current, while facile chemisorption by O2 upon air-exposure causes degradation of electron transport.

  20. Capacitance characteristics of metal-oxide-semiconductor capacitors with a single layer of embedded nickel nanoparticles for the application of nonvolatile memory

    International Nuclear Information System (INIS)

    Wei, Li; Ling, Xu; Wei-Ming, Zhao; Hong-Lin, Ding; Zhong-Yuan, Ma; Jun, Xu; Kun-Ji, Chen


    This paper reports that metal-oxide-semiconductor (MOS) capacitors with a single layer of Ni nanoparticles were successfully fabricated by using electron-beam evaporation and rapid thermal annealing for application to nonvolatile memory. Experimental scanning electron microscopy images showed that Ni nanoparticles of about 5 nm in diameter were clearly embedded in the SiO 2 layer on p-type Si (100). Capacitance–voltage measurements of the MOS capacitor show large flat-band voltage shifts of 1.8 V, which indicate the presence of charge storage in the nickel nanoparticles. In addition, the charge-retention characteristics of MOS capacitors with Ni nanoparticles were investigated by using capacitance–time measurements. The results showed that there was a decay of the capacitance embedded with Ni nanoparticles for an electron charge after 10 4 s. But only a slight decay of the capacitance originating from hole charging was observed. The present results indicate that this technique is promising for the efficient formation or insertion of metal nanoparticles inside MOS structures. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  1. Correlation between (in)commensurate domains of multilayer epitaxial graphene grown on SiC(0 0 0 1-bar ) and single layer electronic behavior

    International Nuclear Information System (INIS)

    Mendes-de-Sa, T G; Goncalves, A M B; Matos, M J S; Coelho, P M; Magalhaes-Paniago, R; Lacerda, R G


    A systematic study of the evolution of the electronic behavior and atomic structure of multilayer epitaxial graphene (MEG) as a function of growth time was performed. MEG was obtained by sublimation of a 4H-SiC(0 0 0 1-bar ) substrate in an argon atmosphere. Raman spectroscopy and x-ray diffraction were carried out in samples grown for different times. For 30 min of growth the sample Raman signal is similar to that of graphite, while for 60 min the spectrum becomes equivalent to that of exfoliated graphene. Conventional x-ray diffraction reveals that all the samples have two different (0001) lattice spacings. Grazing incidence x-ray diffraction shows that thin films are composed of rotated (commensurate) structures formed by adjacent graphene layers. Thick films are almost completely disordered. This result can be directly correlated to the single layer electronic behavior of the films as observed by Raman spectroscopy. Finally, to understand the change in lattice spacings as a result of layer rotation, we have carried out first principles calculations (using density functional theory) of the observed commensurate structures. (paper)

  2. A Complete Reporting of MCNP6 Validation Results for Electron Energy Deposition in Single-Layer Extended Media for Source Energies <= 1-MeV

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, David A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hughes, Henry Grady [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    In this paper, we expand on previous validation work by Dixon and Hughes. That is, we present a more complete suite of validation results with respect to to the well-known Lockwood energy deposition experiment. Lockwood et al. measured energy deposition in materials including beryllium, carbon, aluminum, iron, copper, molybdenum, tantalum, and uranium, for both single- and multi-layer 1-D geometries. Source configurations included mono-energetic, mono-directional electron beams with energies of 0.05-MeV, 0.1-MeV, 0.3- MeV, 0.5-MeV, and 1-MeV, in both normal and off-normal angles of incidence. These experiments are particularly valuable for validating electron transport codes, because they are closely represented by simulating pencil beams incident on 1-D semi-infinite slabs with and without material interfaces. Herein, we include total energy deposition and energy deposition profiles for the single-layer experiments reported by Lockwood et al. (a more complete multi-layer validation will follow in another report).

  3. Effect of single-layer centrifugation or washing on frozen-thawed donkey semen quality: Do they have the same effect regardless of the quality of the sample? (United States)

    Ortiz, I; Dorado, J; Morrell, J M; Crespo, F; Gosálvez, J; Gálvez, M J; Acha, D; Hidalgo, M


    The aims of this study were to determine the sperm quality of frozen-thawed donkey sperm samples after single-layer centrifugation (SLC) using Androcoll-E in comparison to sperm washing or no centrifugation and to determine if the effect on the sperm quality after SLC or sperm washing depends on the quality of the sample. Frozen-thawed sperm samples from Andalusian donkeys were divided into three aliquots, and they were processed using three different techniques after thawing: uncentrifuged diluted control (UDC), sperm washing (SW), and SLC. Afterward, sperm quality index was estimated by integrating all parameters (total and progressive sperm motility, membrane integrity, and DNA fragmentation) in a single value. The relationship between the sperm quality of thawed UDC samples and the effect on sperm parameters in SW and SLC-selected samples was assessed. Sperm quality index was significantly higher (P < 0.001) in SLC (0.8 ± 0.0) samples than that in UDC (0.6 ± 0.0) and SW (0.6 ± 0.0) samples, regardless of the sperm quality index after thawing of the sperm sample. In conclusion, SLC of frozen-thawed donkey spermatozoa using Androcoll-E-Small can be a suitable procedure for selecting frozen-thawed donkey sperm with better quality, in particular in those samples where an improvement in motility is needed. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. The effect of two pre-cryopreservation single layer colloidal centrifugation protocols in combination with different freezing extenders on the fragmentation dynamics of thawed equine sperm DNA. (United States)

    Gutiérrez-Cepeda, Luna; Fernández, Alvaro; Crespo, Francisco; Ramírez, Miguel Ángel; Gosálvez, Jaime; Serres, Consuelo


    Variability among stallions in terms of semen cryopreservation quality renders it difficult to arrive at a standardized cryopreservation method. Different extenders and processing techniques (such us colloidal centrifugation) are used in order to optimize post-thaw sperm quality. Sperm chromatin integrity analysis is an effective tool for assessing such quality. The aim of the present study was to compare the effect of two single layer colloidal centrifugation protocols (prior to cryopreservation) in combination with three commercial freezing extenders on the post-thaw chromatin integrity of equine sperm samples at different post-thaw incubation (37°C) times (i.e., their DNA fragmentation dynamics). Post-thaw DNA fragmentation levels in semen samples subjected to either of the colloidal centrifugation protocols were significantly lower (pcentrifugation. The use of InraFreeze® extender was associated with significantly less DNA fragmentation than the use of Botu-Crio® extender at 6 h of incubation, and than the use of either Botu-Crio® or Gent® extender at 24 h of incubation (pcentrifugation performed with extended or raw semen prior to cryopreservation reduces DNA fragmentation during the first four hours after thawing. Further studies are needed to determine the influence of freezing extenders on equine sperm DNA fragmentation dynamics.

  5. The efficiency enhancement of single-layer solution-processed blue phosphorescent organic light emitting diodes by hole injection layer modification

    International Nuclear Information System (INIS)

    Yeoh, K H; Talik, N A; Whitcher, T J; Ng, C Y B; Woon, K L


    Poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) PEDOT : PSS is extensively used as a hole injection layer (HIL) in solution-processed organic light emitting diodes (OLEDs). The high work function of a HIL is crucial in improving OLED efficiency. The work function of PEDOT : PSS is usually around 5.1–5.3 eV. By adding perfluorinated ionomer (PFI), the work function of PEDOT : PSS has been reported to reach as high as 5.95 eV. We investigated the effects of PFI-modified PEDOT : PSS in a single-layer solution-processed blue phosphorescent OLED (PHOLED). We observed that high concentrations of a PFI in PEDOT : PSS has detrimental effects on the device efficiency due to the low conductivity of the PFI. Using this approach, blue PHOLEDs with efficiencies of 9.4 lm W −1 (18.2 cd A −1 ) and 7.9 lm W −1 (20.4 cd A −1 ) at 100 cd m −2 and 1000 cd m −2 , respectively, were demonstrated. (paper)

  6. Comparison of 10-0 polypropylene and 10-0 nylon sutures in rat arterial anastomosis. (United States)

    Chen, L E; Seaber, A V; Urbaniak, J R


    The selection of suture materials is an important factor in further improving the results of microsurgical operations. In this study, two kinds of nonabsorbable suture materials, 10-0 polypropylene and 10-0 nylon monofilament, were compared in end-to-end anastomosis of 66 femoral arteries of adult rats. Both suture types were of identical size (70 microns needle/28 microns suture) and each artery received eight sutures. The vessels were harvested at various intervals from 2 hr to 180 days postoperatively and were evaluated by pathology, radiology, and tensile strength test. The results show that both sutures are capable of achieving excellent long-term patency (100%) of anastomosed sites. Polypropylene suture was equivalent to nylon in mechanical integrity of the anastomosis sites but was superior in handling, knotting, and biocompatibility. These physical and biological properties of polypropylene sutures may offer the benefits of diminished early and late complications at anastomosis sites and reduced operation time. Enhancement of contrast against surrounding tissue may make polypropylene a superior alternative to nylon sutures for microsurgical use.

  7. Risk factors for suture requirement and early hypotony in 23-gauge vitrectomy for complex vitreoretinal diseases. (United States)

    Küçük, Erkut; Yılmaz, Uğur; Zor, Kürşad Ramazan; Kalaycı, Defne; Sarıkatipoğlu, Hikmet


    To find out the rate of suture requirement and post-operative hypotony in a series of 23-gauge pars plana vitrectomy cases and analyze the factors affecting post-operative hypotony and leakage of sclerotomy leading to suture placement. This is a single-center retrospective interventional case series. Eighty-four eyes underwent 23-gauge vitrectomy. Primary endpoint measures were rate of leakage of 23-gauge sclerotomies requiring suture placement at the end of surgery and rate of early post-operative hypotony. Secondary endpoint measures were risk factors for early hypotony and leakage requiring suture placement at the end of surgery. Suture placement in at least one sclerotomy because of sclerotomy leakage was required in 28.6 % (24 of 84) of eyes at the end of surgery. Early post-operative hypotony was seen in 14.3 % (12 of 84). Silicone oil endotamponade and single-step surgery were found as factors increasing the risk of sclerotomy leakage leading to suture placement. Suture placement was the only significant factor increasing the risk of early post-operative hypotony. Sclerotomy sutures may be required in 23-gauge surgery, more frequently in cases of single-step sclerotomy and/or silicone oil endotamponade. Meticulous suturation of leaking sclerotomies may decrease the rate of post-operative hypotony.

  8. Osteoprotegerin deficiency results in disruption of posterofrontal suture closure in mice: implications in nonsyndromic craniosynostosis. (United States)

    Beederman, Maureen; Kim, Stephanie H; Rogers, M Rose; Lyon, Sarah M; He, Tong-Chuan; Reid, Russell R


    Little is known about the role of osteoclasts in cranial suture fusion. Osteoclasts are predominantly regulated by receptor activator of nuclear factor kappa B and receptor activator of nuclear factor kappa B ligand, both of which lead to osteoclast differentiation, activation, and survival; and osteoprotegerin, a soluble inhibitor of receptor activator of nuclear factor kappa B. The authors' work examines the role of osteoprotegerin in this process using knockout technology. Wild-type, osteoprotegerin-heterozygous, and osteoprotegerin-knockout mice were imaged by serial micro-computed tomography at 3, 5, 7, 9, and 16 weeks. Suture density measurements and craniometric analysis were performed at these same time points. Posterofrontal sutures were harvested from mice after the week-16 time point and analyzed by means of histochemistry. Micro-computed tomographic analysis of the posterofrontal suture revealed reduced suture fusion in osteoprotegerin-knockout mice compared with wild-type and heterozygous littermates. Osteoprotegerin deficiency resulted in a statistically significant decrease in suture bone density in knockout mice. There was no reduction in the density of non-suture-containing calvarial bone between wild-type and osteoprotegerin-knockout mice. Histochemistry of suture sections supported these micro-computed tomographic findings. Finally, osteoprotegerin-knockout mice had reduced anteroposterior skull distance at all time points and an increased interorbital distance at the week-16 time point. The authors' data suggest that perturbations in the expression of osteoprotegerin and subsequent changes in osteoclastogenesis lead to alterations in murine cranial and posterofrontal suture morphology.

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

    Directory of Open Access Journals (Sweden)

    Ann Katharin Reckhenrich

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

  10. Biomechanical testing of new meniscal repair techniques containing ultra high-molecular weight polyethylene suture. (United States)

    Barber, F Alan; Herbert, Morley A; Schroeder, F Alexander; Aziz-Jacobo, Jorge; Sutker, Michael J


    To evaluate the biomechanical characteristics of current meniscal repair techniques containing ultra high-molecular weight polyethylene (UHMWPE) suture with and without cyclic loading. Vertical longitudinal cuts made in porcine menisci were secured with a single repair device. Noncycled and cycled (500 cycles) biomechanical tests were performed on the following groups: group 1, No. 2-0 Mersilene vertical suture (Ethicon, Somerville, NJ); group 2, No. 2-0 Orthocord vertical suture (DePuy Mitek, Westwood, MA); group 3, No. 0 Ultrabraid vertical suture (Smith & Nephew Endoscopy, Andover, MA); group 4, No. 2-0 FiberWire vertical suture (Arthrex, Naples, FL); group 5, vertically oriented mattress suture by use of an Ultra FasT-Fix device (Smith & Nephew Endoscopy) with No. 0 Ultrabraid; group 6, vertically oriented mattress suture by use of a RapidLoc A2 device (DePuy Mitek) with No. 2-0 Orthocord suture; group 7, vertically oriented stitch by use of a MaxFire device with MaxBraid PE suture (Biomet Sports Medicine, Warsaw, IN); and group 8, an obliquely oriented stitch of No. 0 UHMWPE suture inserted by use of a CrossFix device (Cayenne Medical, Scottsdale, AZ). Endpoints were failure loads, failure modes, stiffness, and cyclic displacement. Mean single-pull loads were calculated for Ultra FasT-Fix (121 N), FiberWire (110 N), MaxFire (130 N), Mersilene (84 N), Orthocord (124 N), RapidLoc A2 (86 N), CrossFix (77 N), and Ultrabraid (109 N). After 500 cyclic loads, the Orthocord (222 N) repair was stronger than the others: Ultra FasT-Fix (110 N), FiberWire (117 N), MaxFire (132 N), Mersilene (89 N), RapidLoc A2 (108 N), CrossFix (95 N), and Ultrabraid (126 N) (P Fix, RapidLoc A2, and MaxFire) were comparable to the isolated UHMWPE-containing suture repairs on single-failure load testing. UHMWPE-containing suture repairs are stronger than braided polyester suture repairs, but pure UHMWPE suture (Ultrabraid) elongated more during cycling. Orthocord suture is significantly

  11. Rhinoplasty: a simplified, three-stitch, open tip suture technique. Part I: primary rhinoplasty. (United States)

    Daniel, R K


    Tip suture techniques offer a reliable and dramatic method of tip modification without needing to interrupt the alar rim strip or add tip grafts. The present simplified three-stitch technique consists of the following: (1) a strut suture to fix the columella strut between the crura, (2) bilateral domal creation sutures to create tip definition, and (3) a domal equalization suture to narrow and align the domes. If required, columella septal sutures can be added; either a dorsal rotational suture or a transfixion projection suture can be used. This simplified method represents a refinement based on more than 13 years of experience with tip suture techniques. It does not require a complex operative sequence or specialized sutures. Primary indications are moderate tip deformities of inadequate definition and excessive width and certain specific tip deformities, including the parenthesis tip and nostril/tip disproportion. The primary contraindications are for patients with minor tip deformities that are best done through a closed approach and those with severe tip deformities requiring an open structure graft. The technique is simple, efficacious, and easily learned.

  12. Median sternotomy: comparative testing of braided superelastic and monofilament stainless steel sternal sutures. (United States)

    Baril, Y; Brailovski, V; Chartrand, M; Terriault, P; Cartier, R


    A new device to reduce the risk of post-operative complications following median sternotomy is proposed, made of a superelastic shape memory alloy and called a braided tubular superelastic (BTS) suture. This study compares the viability of the BTS suture with that of the standard monofilament stainless steel (MSS) suture. A custom test bench was developed to perform comparative testing of the two sternal closure systems. Sternal models made of polyurethane were closed using common wiring configurations. Static and dynamic tensile separation forces, up to a maximum of 1200 N, were then applied to the closed sternums. The MSS and BTS sutures are compared in terms of the force required to open completely the sternum, the compression force at the sternum midline, and the permanent sternum opening. With a smaller sternum opening and a higher tensile separation force, the MSS suture showed greater rigidity than the BTS suture. The BTS suture, however, displayed a better capacity to reapply compression forces at the sternum midline following the repetitive application and release of tensile separation forces. These results confirm the potential of the BTS suture technology, but further studies using cadaveric sterna are needed to attest definitely to the benefits of using the BTS suture to improve bone healing.

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

    LENUS (Irish Health Repository)

    Tiong, William H C


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

  14. Hysteresis of a biomaterial: influence of sutures and biological adhesives. (United States)

    García Páez, J M; Carrera, A; Jorge, E; Millán, I; Cordón, A; Rocha, A; Maestro, M; Castillo-Olivares, J L


    We studied the changes in energy consumption of samples of calf pericardium, when joined or not joined by sutures and adhesives, by means of hysteretic cycles. Sixty-four samples were subsequently subjected to tensile stress until rupture. An overlapping suture sewn in the form of a rectangle presented an acceptable mean resistance to rupture of over 10 MPa, although lower than the mean values in an unsutured control series where the mean resistance surpassed 15 MPa. The contribution of an acrylic adhesive to the resistance to rupture was negligible. The sutured samples that were reinforced with adhesives and had not been subjected to hysteretic cycles prior to rupture showed an anisotropic behavior. This behavior appeared to be lost in all the samples that underwent hysteretic cycles. We found an inflection point in the stress/strain curve following the stepwise increase in the load, with a value greater than and proximate to the final load applied. This inflection should be analyzed by means of microscopy. Finally, the mathematical relationship between the energy consumed and the stress applied, the strain or deformation produced and the number of cycles of hysteresis to which the samples were subjected was established as the ultimate objective of this study. The bonding systems provoked a greater consumption of energy, with the greatest consumption corresponding to the first cycle in all the series assayed. An equation relating the energy consumption in a sample to the number of hysteretic cycles to which it was subjected was obtained. Its asymptote on the x-axis indicates the energy consumption for a theoretical number of cycles, making it possible to estimate the durability of the sample.

  15. Mini-open Subpectoral Biceps Tenodesis Using a Suture Anchor. (United States)

    Arena, Christopher; Dhawan, Aman


    The long head of the biceps (LHB) tendon is a potential source of shoulder pain encountered by orthopaedic surgeons. A multitude of approaches to addressing LHB tendinopathy have been described. These include various surgical techniques such as tenodesis versus tenotomy, an arthroscopic versus an open approach, and differing methods of tenodesis fixation. Our preferred approach to addressing LHB tendinopathy is through a mini-open approach using a double-loaded 4.5-mm suture anchor. This Technical Note with accompanying video describes our technique for performing this procedure, as well as supporting clinical evidence and technical pearls.

  16. Endoscopic sutured gastroplasty: procedure evolution from first-in-man cases through current technique. (United States)

    Kumar, Nitin; Abu Dayyeh, Barham K; Lopez-Nava Breviere, Gontrand; Galvao Neto, Manoel P; Sahdala, Nicole P; Shaikh, Sohail N; Hawes, Robert H; Gostout, Christopher J; Goenka, Mahesh K; Orillac, Jorge R; Alvarado, Alonso; Jirapinyo, Pichamol; Zundel, Natan; Thompson, Christopher C


    Endoscopic sutured gastroplasty (ESG) has evolved over time. With the advent of full-thickness endoscopic suturing, an efficient technique for ESG was developed and refined. This prospective first-in-man trial started in April 2012 and represents the first use of full-thickness endoscopic suturing for primary obesity therapy. The trial focused on procedure development, reproducibility, safety, and short-term efficacy. The trial was performed at centers in five countries, in three phases. Phase I was evaluation of safety and technical feasibility of various procedure techniques; stitch patterns and sequences were assessed for efficiency, safety, and feasibility. Phase II entailed continued procedure refinement to establish a standardized technique. Phase III entailed evaluation of technical feasibility and weight loss outcomes in 77 patients; the procedure was performed using the standardized technique, and there was no procedure development. Data were prospectively collected into a registry. In Phase I, the procedure was created and modified to improve time efficiency. Safety and technical feasibility were established, and short-term weight loss was demonstrated. In Phase II, a number of stitch patterns were attempted, and the stitch pattern was modified and finalized. 22 patients were included, and 1-year total weight loss was 17.3 ± 2.6%. In Phase III, conformity with the final technique was high. 77 patients were included, with a mean BMI of 36.1 ± 0.6 kg/m 2 . Mean weight loss was 16.0 ± 0.8% at 6 months and 17.4 ± 1.2% at 12 months (n = 44). Postprocedural nausea, vomiting, and epigastric pain were frequently reported; there were no reported significant adverse events post-procedure or during the follow-up period. Following a methodical procedure development phase, ESG demonstrated safety and short-term efficacy in this trial. The procedure also achieved meaningful weight loss during the follow-up period.

  17. Endoscopic suture repair of full-thickness esophagotomy during per-oral esophageal myotomy for achalasia. (United States)

    Kurian, Ashwin A; Bhayani, Neil H; Reavis, Kevin; Dunst, Christy; Swanström, Lee


    Per-oral endoscopic myotomy (POEM) requires advanced flexible endoscopic skills, especially in the management of complications. We present a full-thickness esophagotomy while performing POEM and repair using an endoscopic suturing device. An anterior esophageal 2 cm mucosectomy is created 7-10 cm proximal to the gastroesophageal junction after a submucosal wheal is raised. A submucosal tunnel is created and extended to 2 cm on the gastric cardia. A selective circular myotomy is performed. The mucosectomy is closed using endoscopic clips. An inadvertent full-thickness esophagotomy was created while performing the mucosotomy on an inadequate submucosal wheal. We were able to resume the POEM technique at the initial esophagotomy site. There was a discussion to convert to laparoscopy. However, as we succeeded in creating the tunnel, we continued with the POEM technique. After the selective myotomy was completed, we used an endoluminal suturing device (Overstitch, Apollo Endosurgery, Austin TX) to close the full-thickness esophagotomy in two layers (muscular, mucosal). A covered stent was not an option because the esophagus was dilated, which precluded adequate apposition. The patient had an uneventful postoperative course. At 9-month follow-up, had excellent palliation of dysphagia without reflux. This case demonstrates the importance of identifying extramucosal intrathoracic anatomy, thus emphasizing the need for an experienced surgeon to perform these procedures, or at a minimum to be highly involved. Raising an adequate wheal is crucial before mucosectomy. Inadequacy of the wheal may reflect local esophageal fibrosis. If this fails at multiple locations in the esophagus, it may be prudent to convert to laparoscopy. This case also demonstrates the need for advanced flexible endoscopic therapeutic tools and a multidisciplinary approach to manage potential complications.

  18. Inhibition of bone resorption by bisphosphonates interferes with orthodontically induced midpalatal suture expansion in mice. (United States)

    Koehne, Till; Kahl-Nieke, Bärbel; Amling, Michael; Korbmacher-Steiner, Heike


    Craniofacial sutures are important growth sites for skull development and are sensitive to mechanical stress. In order to determine the role of bone resorption in stress-mediated sutural bone growth, midpalatal suture expansion was performed in mice receiving alendronate, an anti-resorptive bisphosphonate. The midpalatal sutures of 8-week-old C57BL/6 mice were expanded by orthodontic wires over the period of 2 weeks. Mice with maxillary expansion without drug treatment as well as untreated animals served as controls. Skulls were analyzed with micro-computed tomography (micro-CT), immunohistochemistry and histology. Maxillary expansion in mice without drug treatment resulted in an increase of TRAP-positive osteoclasts. In contrast, no increase in osteoclasts was observed in expanded sutures of mice with bisphosphonate treatment. Double calcein labeling demonstrated rapid bone formation on the oral edges of the expanded sutures in mice without bisphosphonate treatment. Less bone formation was observed in bisphosphonate-treated mice after expansion. Histology revealed that the sutural architecture was reestablished in expanded sutures of mice without bisphosphonate treatment. In contrast, the sutural architecture was disorganized and the cartilage had an irregular form, following expansion in bisphosphonate-treated mice. Finally, micro-CT imaging demonstrated that the total amount of maxillary expansion was significantly lower in mice with bisphosphonate treatment as compared to those of mice without drug treatment. In conclusion, our results indicate that osteoclast-mediated bone resorption is needed for maxillary suture expansion and reorganization of sutural architecture. Orthodontic palatal expansion can be complicated in patients with inherited or drug-induced diseases of osteoclast dysfunction.

  19. Subluxation of suture-fixated posterior chamber intraocular lenses a clinicopathologic study. (United States)

    Parekh, Parag; Green, W Richard; Stark, Walter J; Akpek, Esen Karamursel


    To report the occurrence of subluxation of suture-fixated posterior chamber (PC) intraocular lenses (IOL) and elucidate the mechanisms involved. Prospective clinicopathologic study. A single 10-0 Prolene suture explanted from a patient who experienced subluxation of his PC-IOL, 11.5 years after placement. Furthermore, multiple 10-0 Prolene sutures and PC-IOLs used for iris fixation were studied as controls. Scanning electron microscopy (SEM) was used to analyze the surface of the explanted suture. In addition, randomly selected 10-0 Prolene sutures cut with Vannas scissors and cut with the positioning holes of a randomly selected PC-IOL identical to that implanted in the patient's eye were examined as controls. Finally, the positioning holes of several randomly selected, iris-fixated PC-IOLs were studied using SEM with particular attention to surface quality and edge finish. Presence of any signs of suture degradation, the character of the cut edge of the suture, as well as the characteristics of the positioning holes of the PC-IOLs. Scanning electron microscopy of the explanted suture revealed sharply cut edges, without significant degradation of the suture, and no intact loop. Scanning electron microscopy of the control suture cut with a PC-IOL demonstrated a similarly cut edge. The positioning holes of the examined PC-IOLs had a sharp edge, and some also had an imperfect finish. We conclude that the surface properties of the positioning holes lead to cutting of the suture, and subsequent subluxation of the PC-IOL.

  20. Assessing suturing techniques using a virtual reality surgical simulator. (United States)

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


    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.

  1. First principles analysis of the CDW instability of single-layer 1T-TiSe2 and its evolution with charge carrier density (United States)

    Guster, Bogdan; Canadell, Enric; Pruneda, Miguel; Ordejón, Pablo


    We present a density functional theory study of the electronic structure of single-layer TiSe2, and focus on the charge density wave (CDW) instability present on this 2D material. We explain the 2× 2 periodicity of the CDW from the phonon band structure of the undistorted crystal, which is unstable under one of the phonon modes at the M point. This can be understood in terms of a partial band gap opening at the Fermi level, which we describe on the basis of the symmetry of the involved crystal orbitals, leading to an energy gain upon the displacement of the atoms following the phonon mode in a 2  ×  1 structure. Furthermore, the combination of the corresponding phonons for the three inequivalent M points of the Brillouin zone leads to the 2  ×  2 distortion characteristic of the CDW state. This leads to a further opening of a full gap, which reduces the energy of the 2  ×  2 structure compared to the 2  ×  1 one of a single M point phonon, and makes the CDW structure the most stable one. We also analyze the effect of charge injection into the layer on the structural instability. We predict that the 2  ×  2 structure only survives for a certain range of doping levels, both for electrons and for holes, as doping reduces the energy gain due to the gap opening. We predict the transition from the commensurate 2  ×  2 distortion to an incommensurate one with increasing wavelength upon increasing the doping level, followed by the appearance of the undistorted 1  ×  1 structure for larger carrier concentrations.

  2. Radiative effect differences between multi-layered and single-layer clouds derived from CERES, CALIPSO, and CloudSat data

    International Nuclear Information System (INIS)

    Li Jiming; Yi Yuhong; Minnis, Patrick; Huang Jianping; Yan Hongru; Ma Yuejie; Wang Wencai; Kirk Ayers, J.


    Clouds alter general circulation through modification of the radiative heating profile within the atmosphere. Their effects are complex and depend on height, vertical structure, and phase. The instantaneous cloud radiative effect (CRE) induced by multi-layered (ML) and single-layer (SL) clouds is estimated by analyzing data collected by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), CloudSat, and Clouds and Earth's Radiation Energy Budget System (CERES) missions from March 2007 through February 2008. The CRE differences between ML and SL clouds at the top of the atmosphere (TOA) and at the surface were also examined. The zonal mean shortwave (SW) CRE differences between the ML and SL clouds at the TOA and surface were positive at most latitudes, peaking at 120 W m -2 in the tropics and dropping to -30 W m -2 at higher latitudes. This indicated that the ML clouds usually reflected less sunlight at the TOA and transmitted more to the surface than the SL clouds, due to their higher cloud top heights. The zonal mean longwave (LW) CRE differences between ML and SL clouds at the TOA and surface were relatively small, ranging from -30 to 30 W m -2 . This showed that the ML clouds only increased the amount of thermal radiation at the TOA relative to the SL clouds in the tropics, decreasing it elsewhere. In other words, ML clouds tended to cool the atmosphere in the tropics and warm it elsewhere when compared to SL clouds. The zonal mean net CRE differences were positive at most latitudes and dominated by the SW CRE differences.

  3. Adsorption of DNA/RNA nucleobases onto single-layer MoS2 and Li-Doped MoS2: A dispersion-corrected DFT study (United States)

    Sadeghi, Meisam; Jahanshahi, Mohsen; Ghorbanzadeh, Morteza; Najafpour, Ghasem


    The kind of sensing platform in nano biosensor plays an important role in nucleic acid sequence detection. It has been demonstrated that graphene does not have an intrinsic band gap; therefore, transition metal dichalcogenides (TMDs) are desirable materials for electronic base detection. In the present work, a comparative study of the adsorption of the DNA/RNA nucleobases [Adenine (A), Cytosine (C) Guanine (G), Thymine (T) and Uracil (U)] onto the single-layer molybdenum disulfide (MoS2) and Li-doped MoS2 (Li-MoS2) as a sensing surfaces was investigated by using Dispersion-corrected Density Functional Theory (D-DFT) calculations and different measure of equilibrium distances, charge transfers and binding energies for the various nucleobases were calculated. The results revealed that the interactions between the nucleobases and the MoS2 can be strongly enhanced by introducing metal atom, due to significant charge transfer from the Li atom to the MoS2 when Lithium is placed on top of the MoS2. Furthermore, the binding energies of the five nucleobases were in the range of -0.734 to -0.816 eV for MoS2 and -1.47 to -1.80 eV for the Li-MoS2. Also, nucleobases were adsorbed onto MoS2 sheets via the van der Waals (vdW) force. This high affinity and the renewable properties of the biosensing platform demonstrated that Li-MoS2 nanosheet is biocompatible and suitable for nucleic acid analysis.

  4. Performance assessment of a single-layer moisture store-and-release cover system at a mine waste rock pile in a seasonally humid region (Nova Scotia, Canada). (United States)

    Power, Christopher; Ramasamy, Murugan; Mkandawire, Martin


    Cover systems are commonly applied to mine waste rock piles (WRPs) to control acid mine drainage (AMD). Single-layer covers utilize the moisture "store-and-release" concept to first store and then release moisture back to the atmosphere via evapotranspiration. Although more commonly used in semi-arid and arid climates, store-and-release covers remain an attractive option in humid climates due to the low cost and relative simplicity of installation. However, knowledge of their performance in these climates is limited. The objective of this study was to assess the performance of moisture store-and-release covers at full-scale WRPs located in humid climates. This cover type was installed at a WRP in Nova Scotia, Canada, alongside state-of-the-art monitoring instrumentation. Field monitoring was conducted over 5 years to assess key components such as meteorological conditions, cover material water dynamics, net percolation, surface runoff, pore-gas, environmental receptor water quality, landform stability and vegetation. Water balances indicate small reductions in water influx to the waste rock (i.e., 34 to 28% of precipitation) with the diminished AMD release also apparent by small improvements in groundwater quality (increase in pH, decrease in sulfate/metals). Surface water quality analysis and field observations of vegetative/aquatic life demonstrate significant improvements in the surface water receptor. The WRP landform is stable and the vegetative cover is thriving. This study has shown that while a simple store-and-release cover may not be a highly effective barrier to water infiltration in humid climates, it can be used to (i) eliminate contaminated surface water runoff, (ii) minimize AMD impacts to surface water receptor(s), (iii) maintain a stable landform, and (iv) provide a sustainable vegetative canopy.

  5. Structural effects on charge order in single-layered manganites R{sub 1-x}A{sub 1+x}MnO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Engelmayer, Johannes; Ulbrich, Holger; Weber, Lisa; Braden, Markus; Lorenz, Thomas [II. Physikalisches Institut, Universitaet zu Koeln (Germany)


    Single-layered manganites show a complex interplay between charge, orbital, and magnetic degrees of freedom. For half-doped (x=1/2) R{sub 1-x}A{sub 1+x}MnO{sub 4} (R=Pr,La; A=Ca,Sr) the so-called Goodenough model is well established. This model proposes a site-centered charge order with a checkerboard pattern of Mn{sup 3+} and Mn{sup 4+} ions accompanied by an orbital order. Furthermore a magnetic order develops with ferromagnetic three-spin zig-zag chains and antiferromagnetic interchain coupling. For x=2/3 the charge order appears as stripe pattern with two adjacent stripes of Mn{sup 4+} ions alternating with a single stripe of Mn{sup 3+} ions, while in the magnetically ordered state four-spin zig-zag chains arise. For a deeper understanding of the emergence of charge order, it is appropriate to vary on the one hand the elements R and A while keeping the doping level x constant - involving structural changes at fixed charge carrier density - and on the other hand change the doping level with the same R and A. Therefore various single crystals of R{sub 1-x}A{sub 1+x}MnO{sub 4} with R=(Pr, Nd, Sm, Tb), A=(Ca, Sr) and 0.5 ≤ x ≤ 0.7 were grown and their structural parameters were determined by X-ray diffraction. Based on measurements of resistivity, magnetization, specific heat, and crystal structure we discuss the influence of structural variations on the ordering temperature.

  6. [Prevention of surgical infection using reabsorbable antibacterial suture (Vicryl Plus) versus reabsorbable conventional suture in hernioplasty. An experimental study in animals]. (United States)

    Suárez Grau, Juan Manuel; De Toro Crespo, María; Docobo Durántez, Fernando; Rubio Chaves, Carolina; Martín Cartes, Juan Antonio; Docobo Pérez, Fernando


    Surgical site infections are frequent in daily surgical practice. One of the main challenges currently facing surgeons is the prevention and treatment of infections, especially those involving prosthetic material. A new suture (Vicryl Plus) has become available. In vitro studies and experimental models have demonstrated the ability of this suture to inhibit bacterial growth and consequently prevent postsurgical infection. To compare infections provoked in prosthetic implants fixed with reabsorbable conventional sutures with those in meshes fixed with reabsorbable sutures with antiseptic impregnation. Twenty white Wistar rats were used. In each rat, two hernioplasties were performed: one fixed with Vicryl Plus and the other with normal Vicryl. Subsequently, each polypropylene mesh was infected with S. aureus, and the rats remained in individual cages for a week. After 1 week, the rats were sacrificed and the meshes were extracted for macroscopic, microscopic and microbiologic study. Most of the meshes fixed with the new suture (Vicryl Plus) showed macroscopically fewer infections than those fixed with conventional suture, without abscesses and without dehiscence of the hernioplasty. In the microbiological quantitative bacterial study, the number of bacteria quantified per gram of sample was also lower in prostheses fixed with Vicryl Plus. Pathological analysis showed lesser colonization of the mesh and lower inflammatory response with Vicryl Plus than with normal Vicryl. In the statistical analysis, comparison of the medians of both groups and the interquartile ranges of microbial quantification revealed a lower infection rate in the Vicryl Plus group. The infection rate in the surgical site can be reduced by mesh fixation using the new antimicrobial suture (Vicryl Plus). We believe that this type of suture constitutes a new weapon in the fight against postoperative infection, especially in hernioplasty, emergency surgery, and dirty or potentially contaminated

  7. Interactive Virtual Suturing Simulations: Enhancement of Student Learning in Veterinary Medicine (United States)

    Staton, Amy J.; Boyd, Christine B.


    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…

  8. Critical Anatomy Relative to the Sacral Suture: A Postoperative Imaging Study After Robotic Sacrocolpopexy. (United States)

    Crisp, Catrina C; Herfel, Charles V; Pauls, Rachel N; Westermann, Lauren B; Kleeman, Steven D


    This study aimed to characterize pertinent anatomy relative to the sacral suture placed at time of robotic sacrocolpopexy using postoperative computed tomography and magnetic resonance imaging. A vascular clip was placed at the base of the sacral suture at the time of robotic sacrocolpopexy. Six weeks postoperatively, subjects returned for a computed tomography scan and magnetic resonance imaging. Ten subjects completed the study. The middle sacral artery and vein coursed midline or to the left of midline in all the subjects. The left common iliac vein was an average of 26 mm from the sacral suture. To the right of the suture, the right common iliac artery was 18 mm away. Following the right common iliac artery to its bifurcation, the right internal iliac was on average 10 mm from the suture. The bifurcations of the inferior vena cava and the aorta were 33 mm and 54 mm further cephalad, respectively.The right ureter, on average, was 18 mm from the suture. The thickness of the anterior longitudinal ligament was 2 mm.The mean angle of descent of the sacrum was 70 degrees. Lastly, we found that 70% of the time, a vertebral body was directly below the suture; the disc was noted in 30%. We describe critical anatomy surrounding the sacral suture placed during robotic sacrocolpopexy. Proximity of both vascular and urologic structures within 10 to 18 mm, as well as anterior ligament thickness of only 2 mm highlights the importance of adequate exposure, careful dissection, and surgeon expertise.

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

    DEFF Research Database (Denmark)

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


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

  10. A novel technique of rotator cuff repair using spinal needle and suture loop

    Directory of Open Access Journals (Sweden)

    Muzaffar Nasir


    Full Text Available Abstract Background We present a simple technique of arthroscopic rotator cuff repair using a spinal needle and suture loop. Methods With the arthroscope laterally, a spinal needle looped with PDS is inserted percutaneously into the shoulder posteriorly and penetrated through the healthy posterior cuff tear margin. Anteriorly, another spinal needle loaded with PDS is inserted percutaneously to engage the healthy tissue at the anterior tear margin. The suture in the anterior needle is then delivered into the suture loop of the posterior needle using a suture retriever. The posterior needle and loop are then pulled out carrying the anterior suture with it. The two limbs of this suture are then retrieved through a cannula for knotting. The same procedure is then repeated for additional suturing. Suture anchors placed over the greater tuberosity are used to complete the repair. Conclusion This is an easy method of rotator cuff repair using simple instruments and lesser time, hence can be employed at centers with less equipment and at reduced cost to the patient.

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

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    Enora Laas


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

  12. end-to-side nerve suture - a technique to repair peripheral nerve injury

    African Journals Online (AJOL)

    Raubenheimer, Head of the Department of Oral Pathology and. Oral Biology, Faculty of Dentistry, MEDUNSA, for the meticulous histology investigations. References. 1. Mennen U. End-lo-side nerve suture in the non-human primate. Hand Surgery 1998; 3(1): 1-6. 2. Mennen U. End-to-side nerve suture in the human patient.

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

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    Maffulli Nicola


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

  14. Intracorporeal suture closure of the internal inguinal and vaginal rings in foals and horses. (United States)

    Caron, John P; Brakenhoff, Jeffrey


    To report a technique for repair or prevention of inguinal hernia in horses using intracorporeal suture closure of the internal inguinal and vaginal rings. Case series. Foals (n=6) and geldings (n=2). After selection of a peri-umbilical telescope portal, instrument portals were made unilaterally or bilaterally, as needed. Herniated viscera was reduced, castration (foals) or spermatic cord remnant transection at the internal inguinal ring (adults) performed, and then simple interrupted intracorporeal sutures of synthetic absorbable suture material were used to close the internal inguinal and vaginal rings. There was no recurrence of inguinal hernia. Postoperative morbidity was minimal and cosmetic outcome was comparable to that achieved with conventional, open techniques. Laparoscopic, primary closure of the internal inguinal ring by use of intracorporeal sutures provides a secure barrier to herniation and costs considerably less than using endoscopic staples. Laparoscopic suture closure of the internal inguinal and vaginal rings provides safe and effective repair of inguinal hernia in horses.

  15. Sutures coated with antiseptic pomade to prevent bacterial colonization: a randomized clinical trial. (United States)

    Cruz, Fernando; Leite, Fabiola; Cruz, Gustavo; Cruz, Silvia; Reis, Juarez; Pierce, Matthew; Cruz, Mauro


    The aim of this study was to assess if an antiseptic pomade could reduce the bacterial colonization on multifilament sutures. A randomized clinical trial was conducted with 40 volunteer patients of both sexes aged 18-70, randomly separated into experimental (n = 20) and control (n = 20) groups. The experimental group received pomade-coated sutures (iodoform + calendula) and the control group uncoated sutures. Two millimeters of the suture was harvested from each patient from the 1st to the 15th postoperative day. The bacteria that had adhered to them were cultured. The number of colony-forming units per milliliter (CFU/mL) was determined and the groups were compared using the Mann-Whitney statistical test (P antiseptic pomade was effective in reducing bacterial colonization on silk braided sutures. Copyright © 2013 Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Cheng Hong Yeo


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

  17. Influence of knot configuration and tying technique on the mechanical performance of sutures. (United States)

    Zimmer, C A; Thacker, J G; Powell, D M; Bellian, K T; Becker, D G; Rodeheaver, G T; Edlich, R F


    The purpose of this investigation was to determine the influence of knot configuration and tying technique on the mechanical performance of surgical sutures. Multifilament and monofilament nylon sutures were selected for this evaluation because they are commonly used in wound closure. The mechanical performance of these sutures was judged by the following parameters: knot breakage force, configuration of secure knots, and knot run down force. During each test, tension was applied at either rapid or slow rates, which correlates with the physician's speed of tying knots. On the basis of these mechanical performance tests, four throw square (1 = 1 = 1 =1) knots and five throw square (1 = 1 = 1 = 1 = 1) knots are recommended for monofilament nylon and multifilament nylon sutures, respectively, in which the speed of application of forces to the knots is relatively slow. Because these tests can easily be replicated in any laboratory, manufacturers now have a scientific basis for recommending specific tying techniques for their surgical sutures.

  18. SR and LR Union Suture for the Treatment of Myopic Strabismus Fixus: Is Scleral Fixation Necessary?

    Directory of Open Access Journals (Sweden)

    Carol P. S. Lam


    Full Text Available Purpose. To evaluate and compare the effectiveness of scleral fixation SR and LR union suture and nonscleral fixation union suture for the treatment of myopic strabismus fixus. Methods. Retrospective review of 32 eyes of 22 patients with myopic strabismus fixus who had undergone union suture of superior rectus (SR and lateral rectus (LR with or without scleral fixation, and follow-up longer than 6 months at Hong Kong Eye Hospital from 2006 to 2013. Surgical techniques and outcomes in terms of ocular alignment are analyzed. Results. There is significant overall improvement both in postoperative angle of esodeviation (P0.05. Conclusions. Union suture of SR and LR is an effective procedure in correcting myopic strabismus fixus. Fixation of the union suture to the sclera does not improve surgical outcome.

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

    Directory of Open Access Journals (Sweden)

    Klaus Pelz


    In terms of the total number of oral bacteria, and especially oral pathogens, that adhered to suture material, no reduction was demonstrated for Vicryl Plus. The use of triclosan-coated suture material offers no advantage in intraoral surgery.

  20. Novel Technique to Overcome the Nonavailability of a Long Needle 9-0 Polypropylene Suture for Sutured Scleral Fixation of the Posterior Chamber Intraocular Lens Using a Single Fisherman’s Knot

    Directory of Open Access Journals (Sweden)

    Yong Un Shin


    Full Text Available Purpose. To describe a method to overcome the nonavailability of a long needle 9-0 polypropylene suture for sutured scleral fixation of the posterior chamber intraocular lens (PC-IOL using a single fisherman’s knot (SFK. Methods. First, a 10-0 polypropylene suture was passed from the sclera to the ciliary sulcus using a long needle. A 9-0 suture was tied to the unpassed portion of the 10-0 suture with an SFK. We pulled the 10-0 suture to pass the SFK through the sclera, and then we cut the knot and removed the 10-0 suture. IOL fixation with 9-0 sutures used the conventional techniques used for sutured scleral-fixated IOL. Preoperative and postoperative visual acuity, corneal astigmatism, and endothelial cell count and intraoperative/postoperative complications were evaluated. Results. An SFK joining the two sutures was passed through the sclera without breakage or slippage. A total of 35 eyes from 35 patients who underwent sutured scleral fixation of the IOL. An intraoperative complication (minor intraocular hemorrhage was recorded in four cases. Knot exposure, IOL dislocation, subluxation, and retinal detachment were not observed. Conclusions. The SFK offers the opportunity to use 9-0 sutures for the long-term safety and may not require the surgeon to learn any new technique.

  1. Novel Technique to Overcome the Nonavailability of a Long Needle 9-0 Polypropylene Suture for Sutured Scleral Fixation of the Posterior Chamber Intraocular Lens Using a Single Fisherman's Knot. (United States)

    Shin, Yong Un; Seong, Mincheol; Cho, Hee Yoon; Kang, Min Ho


    To describe a method to overcome the nonavailability of a long needle 9-0 polypropylene suture for sutured scleral fixation of the posterior chamber intraocular lens (PC-IOL) using a single fisherman's knot (SFK). First, a 10-0 polypropylene suture was passed from the sclera to the ciliary sulcus using a long needle. A 9-0 suture was tied to the unpassed portion of the 10-0 suture with an SFK. We pulled the 10-0 suture to pass the SFK through the sclera, and then we cut the knot and removed the 10-0 suture. IOL fixation with 9-0 sutures used the conventional techniques used for sutured scleral-fixated IOL. Preoperative and postoperative visual acuity, corneal astigmatism, and endothelial cell count and intraoperative/postoperative complications were evaluated. An SFK joining the two sutures was passed through the sclera without breakage or slippage. A total of 35 eyes from 35 patients who underwent sutured scleral fixation of the IOL. An intraoperative complication (minor intraocular hemorrhage) was recorded in four cases. Knot exposure, IOL dislocation, subluxation, and retinal detachment were not observed. The SFK offers the opportunity to use 9-0 sutures for the long-term safety and may not require the surgeon to learn any new technique.

  2. Biomechanical performance of a collagen meniscus implant with regard to suture material and irrigation fluid. (United States)

    Gwinner, Clemens; von Roth, Philipp; Schmidt, Sebastian; Ode, Jan-Erik; Wulsten, Dag; Hoburg, Arnd


    The role of meniscus scaffolds remains controversial as failure rates remain high. The aim of this study was to evaluate the pullout strength of different suture materials used for fixation of the Collagen Meniscus Implant (CMI) regarding different suture materials, and type or temperature of irrigation fluid. One-hundred and twelve specimens were utilized with horizontal sutures and mounted to a dedicated test device. Loads were applied perpendicular to the CMI, until failure. Two differing suture materials - polydioxanone (PDS) and non-absorbable, braided polyester sutures (NABP) - were evaluated. Additionally, two common irrigation fluids - lactated Ringer's and electrolyte-free, hypotonic Mannitol-Sorbitol solution - were evaluated. Specimens were further evaluated according to different temperatures of the irrigation fluid. Half of the constructs were tested at room temperature (20°C) and half were evaluated at near-core body temperature (37°C). PDS sutures showed a significantly higher load-to-failure compared to NABP sutures (P=0.0008). Regarding the type of irrigation fluid, the electrolyte-free Mannitol-Sorbitol solution showed a significantly higher load-to-failure compared to the overall Ringer group (P b 0.0001). This was equivalent for both the PDS (P=0.015) and for the NABP sutures (P b 0.0001). The temperature of the irrigation fluid did not significantly influence load-to-failure. PDS sutures and electrolyte-free Mannitol-Sorbitol irrigation fluid provided the best biomechanical properties regarding load-to-failure testing. This study underlines the potential to improve construct stability for the CMI by alteration of the suture material and the type of irrigation fluid, which should be considered whenever scaffold fixation is conducted. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Mitral annuloplasty ring suture forces: Impact of surgeon, ring, and use conditions. (United States)

    Pierce, Eric L; Bloodworth, Charles H; Siefert, Andrew W; Easley, Thomas F; Takayama, Tetsushi; Kawamura, Tomonori; Gorman, Robert C; Gorman, Joseph H; Yoganathan, Ajit P


    The study objective was to quantify the effect of ring type, ring-annulus sizing, suture position, and surgeon on the forces required to tie down and constrain a mitral annuloplasty ring to a beating heart. Physio (Edwards Lifesciences, Irvine, Calif) or Profile 3D (Medtronic, Dublin, Ireland) annuloplasty rings were instrumented with suture force transducers and implanted in ovine subjects (N = 23). Tie-down forces and cyclic contractile forces were recorded and analyzed at 10 suture positions and at 3 levels of increasing peak left ventricular pressure. Across all conditions, tie-down force was 2.7 ± 1.4 N and cyclic contractile force was 2.0 ± 1.2 N. Tie-down force was not meaningfully affected by any factor except surgeon. Significant differences in overall and individual tie-down forces were observed between the 2 primary implanting surgeons. No other factors were observed to significantly affect tie-down force. Contractile suture forces were significantly reduced by ring-annulus true sizing. This was driven almost exclusively by Physio cases and by reduction along the anterior aspect, where dehiscence is less common clinically. Contractile suture forces did not differ significantly between ring types. However, when undersizing, Profile 3D forces were significantly more uniform around the annular circumference. A suture's tie-down force did not correlate to its eventual contractile force. Mitral annuloplasty suture loading is influenced by ring type, ring-annulus sizing, suture position, and surgeon, suggesting that reports of dehiscence may not be merely a series of isolated errors. When compared with forces known to cause suture dehiscence, these in vivo suture loading data aid in establishing potential targets for reducing the occurrence of ring dehiscence. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  4. Absorbable versus silk sutures for surgical treatment of trachomatous trichiasis in Ethiopia: a randomised controlled trial.

    Directory of Open Access Journals (Sweden)

    Saul N Rajak


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

  5. Nonabsorbable versus absorbable sutures in large, hang-back medial rectus muscle recessions. (United States)

    Awadein, Ahmed; Marsh, Justin D; Guyton, David L


    To investigate the value of nonabsorbable sutures in reducing the incidence of consecutive exotropia after large, "hang-back" medial rectus recessions. The medical records of patients who underwent medial rectus recession of ≥6.5 mm in individuals ≤2 years of age, or ≥7.0 mm in those >2 years were retrospectively reviewed. Patients were divided into two groups based on suture material used: absorbable, polyglactin 910 sutures (44 patients); nonabsorbable, polyester sutures (50 patients). Preoperative measurements, ductions, strabismus surgery, and postoperative results were analyzed. Inadequate anchoring of the medial rectus muscle was suspected when consecutive exotropia developed 4-7 weeks after surgery after initial satisfactory alignment and was confirmed if during reoperation the medial rectus muscle appeared recessed >2 mm beyond the originally intended recession. Consecutive exotropia due to inadequate anchoring of the medial rectus muscle occurred in 11 of 66 muscles (17%) in the absorbable suture group. The muscle was found 6-10 mm posterior to the intended recession. Limited duction in the field of action of the involved medial rectus muscle occurred in 9 of the 11 muscles (82%). None of the eyes with nonabsorbable sutures showed inadequate anchoring. The incidence of consecutive exotropia was higher in the absorbable suture group (30%) than in the nonabsorbable suture group (6%) (P < 0.005). Using nonabsorbable suture for large, hang-back medial rectus recessions greatly reduces the incidence of consecutive exotropia that can occur when absorbable suture dissolves. Copyright © 2016 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  6. A 3-D CT Analysis of Screw and Suture-Button Fixation of the Syndesmosis. (United States)

    Schon, Jason M; Williams, Brady T; Venderley, Melanie B; Dornan, Grant J; Backus, Jonathon D; Turnbull, Travis Lee; LaPrade, Robert F; Clanton, Thomas O


    Historically, syndesmosis injuries have been repaired with screw fixation; however, some suggest that suture-button constructs may provide a more accurate anatomic and physiologic reduction. The purpose of this study was to compare changes in the volume of the syndesmotic space following screw or suture-button fixation using a preinjury and postoperative 3-D computed tomography (CT) model. The null hypothesis was that no difference would be observed among repair techniques. Twelve pairs of cadaveric specimens were dissected to identify the syndesmotic ligaments. Specimens were imaged with CT prior to the creation of a complete syndesmosis injury and were subsequently repaired using 1 of 3 randomly assigned techniques: (a) one 3.5-mm cortical screw, (b) 1 suture-button, and (c) 2 suture-buttons. Specimens were imaged postoperatively with CT. 3-D models of all scans and tibiofibular joint space volumes were calculated to assess restoration of the native syndesmosis. Analysis of variance and Tukey's method were used to compare least squares mean differences from the intact syndesmosis among repair techniques. For each of the 3 fixation methods, the total postoperative syndesmosis volume was significantly decreased relative to the intact state. The total mean decreases in volume compared with the intact state for the 1-suture-button construct, 2-suture-button construct, and syndesmotic screw were -561 mm 3 (95% CI, -878 to -244), -964 mm 3 (95% CI, -1281 to -647) and -377 mm 3 (95% CI, -694 to -60), respectively. All repairs notably reduced the volume of the syndesmosis beyond the intact state. Fixation with 1 suture-button was not significantly different from screw or 2-suture-button fixation; however, fixation with 2 suture-buttons resulted in significantly decreased volume compared with screw fixation. The results of this study suggest that the 1-suture-button repair technique and the screw fixation repair technique were comparable for reduction of syndesmosis

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

    Directory of Open Access Journals (Sweden)

    Srikanth G


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

  8. [Animal experiment study of healing of the sutured flexor tendon]. (United States)

    Martini, A K; Blimke, B


    The purpose of the present study was to determine whether tendons contain intrinsic cells capable of repair. To accomplish this, rabbit flexor tendons were exposed microsurgically, cut through, resutured and transferred as free transplant into the knee-joint. Immobilisation of the knee-joint will cause progressive formation of adhesions permitting neovascularisation of the transplant. Both is not observed when sutured flexor tendons were put in a knee articulation with full range of joint motion. Transmission electron micrography revealed up to 8 weeks after implantation vital cells and incidences of collagen neosynthesis independently whether adhesions existed or not. Histologically intrinsic repair was confirmed in mobile transplants and mainly initiated by cells of the visceral synovial sheet which form an anatomic-surgical unity with the tendon. In conclusion the importance of the synovial fluid for the tendon nutrition is underlined by the fact that an intrinsic healing of flexor tendon is possible without formation of adhesions.

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

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    Ning Liu


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

  10. An analytical solution for the estimation of the critical available soil water fraction for a single layer water balance model under growing crops

    Directory of Open Access Journals (Sweden)

    N. Brisson


    . The atmospheric demand together with the rooting depth appear as the most important factors. However, when assuming predictable climatic and crop evolution, compensation occurs between those two effects leading to a relative stability of F when the crop is fully developed. Though relying on well-known physical laws, the present approach remains in the framework of single layer models with the same limitations.

  11. Prototype pre-clinical PET scanner with depth-of-interaction measurements using single-layer crystal array and single-ended readout (United States)

    Lee, Min Sun; Kim, Kyeong Yun; Ko, Guen Bae; Lee, Jae Sung


    In this study, we developed a proof-of-concept prototype PET system using a pair of depth-of-interaction (DOI) PET detectors based on the proposed DOI-encoding method and digital silicon photomultiplier (dSiPM). Our novel cost-effective DOI measurement method is based on a triangular-shaped reflector that requires only a single-layer pixelated crystal and single-ended signal readout. The DOI detector consisted of an 18  ×  18 array of unpolished LYSO crystal (1.47  ×  1.47  ×  15 mm3) wrapped with triangular-shaped reflectors. The DOI information was encoded by depth-dependent light distribution tailored by the reflector geometry and DOI correction was performed using four-step depth calibration data and maximum-likelihood (ML) estimation. The detector pair and the object were placed on two motorized rotation stages to demonstrate 12-block ring PET geometry with 11.15 cm diameter. Spatial resolution was measured and phantom and animal imaging studies were performed to investigate imaging performance. All images were reconstructed with and without the DOI correction to examine the impact of our DOI measurement. The pair of dSiPM-based DOI PET detectors showed good physical performances respectively: 2.82 and 3.09 peak-to-valley ratios, 14.30% and 18.95% energy resolution, and 4.28 and 4.24 mm DOI resolution averaged over all crystals and all depths. A sub-millimeter spatial resolution was achieved at the center of the field of view (FOV). After applying ML-based DOI correction, maximum 36.92% improvement was achieved in the radial spatial resolution and a uniform resolution was observed within 5 cm of transverse PET FOV. We successfully acquired phantom and animal images with improved spatial resolution and contrast by using the DOI measurement. The proposed DOI-encoding method was successfully demonstrated in the system level and exhibited good performance, showing its feasibility for animal PET applications with high spatial

  12. Corrosion Resistance Behavior of Single-Layer Cathodic Arc PVD Nitride-Base Coatings in 1M HCl and 3.5 pct NaCl Solutions (United States)

    Adesina, Akeem Yusuf; Gasem, Zuhair M.; Madhan Kumar, Arumugam


    The electrochemical behavior of single-layer TiN, CrN, CrAlN, and TiAlN coatings on 304 stainless steel substrate, deposited using state-of-the-art and industrial size cathodic arc PVD machine, were evaluated in 1M HCl and 3.5 pct NaCl solutions. The corrosion behavior of the blank and coated substrates was analyzed by electrochemical impedance spectroscopy (EIS), linear polarization resistance, and potentiodynamic polarization. Bond-coat layers of pure-Ti, pure-Cr, alloyed-CrAl, and alloyed-TiAl for TiN, CrN, CrAlN, and TiAlN coatings were, respectively, first deposited for improved coating adhesion before the actual coating. The average coating thickness was about 1.80 µm. Results showed that the corrosion potentials ( E corr) of the coated substrates were shifted to more noble values which indicated improvement of the coated substrate resistance to corrosion susceptibility. The corrosion current densities were lower for all coated substrates as compared to the blank substrate. Similarly, EIS parameters showed that these coatings possessed improved resistance to defects and pores in similar solution compared to the same nitride coatings developed by magnetron sputtering. The charge transfer resistance ( R ct) can be ranked in the following order: TiAlN > CrN > TiN > CrAlN in both media except in NaCl solution where R ct of TiN is lowest. While the pore resistance ( R po) followed the order: CrAlN > CrN > TiAlN > TiN in HCl solution and TiAlN > CrN > CrAlN > TiN in NaCl solution. It is found that TiAlN coating has the highest protective efficiencies of 79 and 99 pct in 1M HCl and 3.5 pct NaCl, respectively. SEM analysis of the corroded substrates in both media was also presented.

  13. Strong visible and near infrared photoluminescence from ZnO nanorods/nanowires grown on single layer graphene studied using sub-band gap excitation (United States)

    Biroju, Ravi K.; Giri, P. K.


    Fabrication and optoelectronic applications of graphene based hybrid 2D-1D semiconductor nanostructures have gained tremendous research interest in recent times. Herein, we present a systematic study on the origin and evolution of strong broad band visible and near infrared (NIR) photoluminescence (PL) from vertical ZnO nanorods (NRs) and nanowires (NWs) grown on single layer graphene using both above band gap and sub-band gap optical excitations. High resolution field emission scanning electron microscopy and X-ray diffraction studies are carried out to reveal the morphology and crystalline quality of as-grown and annealed ZnO NRs/NWs on graphene. Room temperature PL studies reveal that besides the UV and visible PL bands, a new near-infrared (NIR) PL emission band appears in the range between 815 nm and 886 nm (1.40-1.52 eV). X-ray photoelectron spectroscopy studies revealed excess oxygen content and unreacted metallic Zn in the as-grown ZnO nanostructures, owing to the low temperature growth by a physical vapor deposition method. Post-growth annealing at 700 °C in the Ar gas ambient results in the enhanced intensity of both visible and NIR PL bands. On the other hand, subsequent high vacuum annealing at 700 °C results in a drastic reduction in the visible PL band and complete suppression of the NIR PL band. PL decay dynamics of green emission in Ar annealed samples show tri-exponential decay on the nanosecond timescale including a very slow decay component (time constant ˜604.5 ns). Based on these results, the NIR PL band comprising two peaks centered at ˜820 nm and ˜860 nm is tentatively assigned to neutral and negatively charged oxygen interstitial (Oi) defects in ZnO, detected experimentally for the first time. The evidence for oxygen induced trap states on the ZnO NW surface is further substantiated by the slow photocurrent response of graphene-ZnO NRs/NWs. These results are important for tunable light emission, photodetection, and other cutting edge

  14. Mesh fixation with glue versus suture for chronic pain and recurrence in Lichtenstein inguinal hernioplasty. (United States)

    Sun, Ping; Cheng, Xiang; Deng, Shichang; Hu, Qinggang; Sun, Yi; Zheng, Qichang


    Chronic pain following mesh-based inguinal hernia repair is frequently reported, and has a significant impact on quality of life. Whether mesh fixation with glue can reduce chronic pain without increasing the recurrence rate is still controversial. To determine whether tissue adhesives can reduce postoperative complications, especially chronic pain, with no increase in recurrence rate, compared with sutures for mesh fixation in Lichtenstein hernia repair. We searched the following electronic databases with no language restrictions: the Cochrane Central Register of Controlled Trials (CENTRAL; issue 4, 2016) in the Cochrane Library (searched 11 May 2016), MEDLINE Ovid (1986 to 11 May 2016), Embase Ovid (1986 to 11 May 2016), Science Citation Index (Web of Science) (1986 to 11 May 2016), CBM (Chinese Biomedical Database), CNKI (China National Knowledge Infrastructure), VIP (a full-text database in China), Wanfang databases. We also checked reference lists of identified papers (included studies and relevant reviews). We included all randomised and quasi-randomised controlled trials comparing glue versus sutures for mesh fixation in Lichtenstein hernia repair. Cluster-RCTs were also eligible. Two review authors extracted data and assessed the risk of bias independently. Dichotomous outcomes were expressed as odds ratio (OR) with 95% confidence intervals (CI). Continuous outcomes were expressed as mean differences (MD) with 95% CIs. Twelve trials with a total of 1932 participants were included in this review. The overall postoperative chronic pain in the glue group was reduced by 37% (OR 0.63, 95% CI 0.44 to 0.91; 10 studies, 1418 participants, low-quality evidence) compared with the suture group. However, the results changed when we conducted subgroup analysis with regard to the type of mesh. Subgroup analysis of included studies using lightweight mesh showed the reduction of chronic pain was less profound and insignificant (OR 0.77, 95% CI 0.50 to 1.17). Subgroup

  15. Biomechanical characteristics of single-row repair in comparison to double-row repair with consideration of the suture configuration and suture material. (United States)

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


    The aim of the study was to evaluate the time zero mechanical properties of single- versus double-row configuration for rotator cuff repair in an animal model with consideration of the stitch technique and suture material. Thirty-two fresh-frozen sheep shoulders were randomly assigned to four repair groups: suture anchor single-row repair coupled with (1) braided, nonabsorbable polyester suture sized USP No. 2 (SRAE) or (2) braided polyblend polyethylene suture sized No. 2 (SRAH). The double-row repair was coupled with (3) USP No. 2 (DRAE) or (4) braided polyblend polyethylene suture No. 2 (DRAH). Arthroscopic Mason-Allen stitches were used (single-row) and combined with medial horizontal mattress stitches (double-row). Shoulders were cyclically loaded from 10 to 180 N. Displacement to gap formation of 5- and 10-mm at the repair site, cycles to failure, and the mode of failure were determined. The ultimate tensile strength was verified in specimens that resisted to 3,000 cycles. DRAE and DRAH had a lower frequency of 5- (P = 0.135) and 10-mm gap formation (P = 0.135). All DRAE and DRAH resisted 3,000 cycles while only three SRAE and one SRAH resisted 3,000 cycles (P 0.05). Double-row suture anchor repair with arthroscopic Mason-Allen/medial mattress stitches provides initial strength superior to single-row repair with arthroscopic Mason-Allen stitches under isometric cyclic loading as well as under ultimate loading conditions. Our results support the concept of double-row fixation with arthroscopic Mason-Allen/medial mattress stitches in rotator cuff tears with improvement of initial fixation strength and ultimate tensile load. Use of new polyblend polyethylene suture material seems not to increase the initial biomechanical aspects of the repair construct.

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

    Directory of Open Access Journals (Sweden)

    Volkan Ergan


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

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

    International Nuclear Information System (INIS)

    Simanovsky, Natalia; Hiller, Nurith; Koplewitz, Benjamin; Rozovsky, Katya


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

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

    Energy Technology Data Exchange (ETDEWEB)

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


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

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

    Energy Technology Data Exchange (ETDEWEB)

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


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

  20. Mechanical properties of commercially available nylon sutures in the United States. (United States)

    Callahan, Travis L; Lear, William; Kruzic, Jamie J; Maughan, Cory B


    Surgeons can choose from a wide selection of commercially available suture brands, which come at a range of prices. There is currently limited evidence in the literature to guide this selection process. This investigation examined the breaking force, stress, and elongation of a variety of commercially available nylon sutures compared to their relative prices. Seven 5-0, nonabsorbable, nylon suture brands were tensile tested in straight, knotted and knot-security configurations according to the procedures outlined by the United States Pharmacopeia for the tensile testing of sutures. Covidien, the cheapest brand tested, had the highest failure load of straight and knot-security tests. Dafilon was found to have the highest breaking force and percent elongation of knot-pull tests. J&J Ethicon and Supramid had the highest percent elongation to failure for straight-pull and knot-security tests, respectively. This study was limited to specific in vitro tensile properties of nylon suture. Other factors affecting suture quality and price, such as needle properties, were not investigated. The data presented in the study provide information for guiding the selection and purchase of sutures according to tensile properties. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 815-819, 2017. © 2016 Wiley Periodicals, Inc.

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

    Directory of Open Access Journals (Sweden)

    Alireza Saied


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

  2. Triclosan-coated sutures and sternal wound infections: a prospective randomized clinical trial. (United States)

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


    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. ( NCT01212315).

  3. Triclosan-coated sutures reduce wound infections after spinal surgery: a retrospective, nonrandomized, clinical study. (United States)

    Ueno, Masaki; Saito, Wataru; Yamagata, Megumu; Imura, Takayuki; Inoue, Gen; Nakazawa, Toshiyuki; Takahira, Naonobu; Uchida, Kentaro; Fukahori, Nobuko; Shimomura, Kiyomi; Takaso, Masashi


    Surgical site infection (SSI) is a serious postoperative complication. The incidence of SSIs is lower in clean orthopedic surgery than in other fields, but it is higher after spinal surgery, reaching 4.15% in high-risk patients. Several studies reported that triclosan-coated polyglactin 910 sutures (Vicryl Plus; Ethicon, Inc., Somerville, NJ, USA) significantly reduced the infection rate in the general surgical, neurosurgical, and thoracic surgical fields. However, there have been no studies on the effects of such coated sutures on the incidence of SSIs in orthopedics. To compare the incidence of wound infections after spinal surgery using triclosan-coated suture materials with that of noncoated ones. A retrospective, nonrandomized, and clinical study. From May 2010 to April 2012, 405 patients underwent a spinal surgical procedure in the Department of Orthopedic Surgery of two university hospitals. The primary outcome was the number of wound infections and dehiscences. Two hundred five patients had a conventional wound closure with polyglactin 910 suture (Vicryl) between May 2010 and April 2011 (Time Period 1 [TP1]), and 200 patients underwent wound closure with triclosan-coated polyglactin 910 suture (Vicryl Plus) between May 2011 and April 2012 (TP2). Statistical comparisons of wound infections, dehiscence, and risk factors for poor wound healing or infection were performed. None of the authors has any conflict of interest associated with this study. There were two cases of wound dehiscence in TP1 and one in TP2 (p=.509). Using noncoated sutures in TP1, eight patients (3.90%) had wound infections, whereas one patient (0.50%) had wound infections in TP2 (using triclosan-coated sutures); the difference was significant (p=.020). The use of triclosan-coated polyglactin 910 sutures instead of polyglactin 910 sutures may reduce the number of wound infections after spinal surgery. Copyright © 2015 Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Phimon Atsawasuwan

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

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

    DEFF Research Database (Denmark)

    Lynnerup, Niels; Jacobsen, Jens Christian Brings


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

  6. Biomechanical Comparison of a First- and a Second-Generation All-Soft Suture Glenoid Anchor (United States)

    Erickson, John; Chiarappa, Frank; Haskel, Jonathan; Rice, Justin; Hyatt, Adam; Monica, James; Dhawan, Aman


    Background: All–soft tissue suture anchors provide advantages of decreased removal of bone and decreased glenoid volume occupied compared with traditional tap or screw-in suture anchors. Previous published data have led to biomechanical concerns with the use of first-generation all-soft suture anchors. Purpose/Hypothesis: The purpose of this study was to evaluate the load to 2-mm displacement and ultimate load to failure of a second-generation all-soft suture anchor, compared with a first-generation anchor and a traditional PEEK (polyether ether ketone) anchor. The null hypothesis was that the newer second-generation anchor will demonstrate no difference in loads to 2-mm displacement after cycling compared with first-generation all-soft suture anchors. Study Design: Controlled laboratory study. Methods: Twenty human cadaveric glenoids were utilized to create 97 total suture anchor sites, and 1 of 3 anchors were randomized and placed into each site: (1) first-generation all-soft suture anchor (Juggerknot; Biomet), (2) second-generation all-soft suture anchor (Suturefix; Smith & Nephew), and (3) a control PEEK anchor (Bioraptor; Smith & Nephew). After initial cyclic loading, load to 2 mm of displacement and ultimate load to failure were measured for each anchor. Results: After cyclic loading, the load to 2-mm displacement was significantly less in first-generation anchors compared with controls (P .05). Conclusion: The newer generation all-soft suture anchors with a theoretically more rigid construct and deployment configuration demonstrate biomechanical characteristics (specifically, with load to 2-mm displacement after cyclic loading) that are improved over first-generation all-soft suture anchors and similar to a traditional solid tap-in anchor. The configuration of these newer generation all-soft suture anchors appears to mitigate the biomechanical concerns of decreased load to failure with first-generation all–soft tissue suture anchors. Clinical Relevance

  7. A new, removable, sliding noose for adjustable-suture strabismus surgery. (United States)

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


    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. Copyright © 2013 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

  8. Comparison of indium 111 oxine-labeled platelet aggregation between sutured and argon laser-assisted vascular anastomoses

    International Nuclear Information System (INIS)

    Fujitani, R.M.; White, R.A.; Kopchok, G.E.; Vlasak, J.; Marcus, C.S.; White, G.H.


    The thrombogenicity of argon laser-assisted vascular anastomoses (LAVAs) was compared with that of sutured vascular anastomoses (SVAs) by measurement of platelet aggregation at the site of repair in a canine model. Sequential 1 cm longitudinal carotid and femoral arteriotomies (n = 80) or jugular and femoral phlebotomies (n = 80) were performed, with each vessel having two tandem, randomly positioned arteriotomies or phlebotomies separated by a 4 cm length of intact vessel. One incision was repaired by SVA with continuous 6-0 polypropylene sutures and the other by argon LAVA. For the laser fusions, argon laser energy was applied to the adventitial surface of the vessel with a 300 micron fiberoptic probe with 0.5 W power, 1100 joules per square centimeter energy fluence, and 150 second exposure per 1 cm length. The arterial and venous segments of SVAs and LAVAs and an equivalent length of normal vessel were harvested at 48 hours (n = 16, 16, 16), 2 weeks (n = 12, 12, 12), and 4 weeks (n = 12, 12, 12). Autologous indium 111 oxine-labeled platelets were injected intravenously 48 hours before removal of the vascular repairs and the radioactivity of the specimens was determined on removal with a NaI (T1) well-type scintillation counter. Anastomotic platelet adherence index (APAI) was calculated as the ratio of emissions of SVA or LAVA to normal reference vessel

  9. Case of colonic intussusception secondary to mobile cecum syndrome repaired by laparoscopic cecopexy using a barbed wound suture device. (United States)

    Yamamoto, Tetsu; Tajima, Yoshitsugu; Hyakudomi, Ryoji; Hirayama, Takanori; Taniura, Takahito; Ishitobi, Kazunari; Hirahara, Noriyuki


    A 27-year-old man with recurrent right lower quadrant pain was admitted to our hospital. Ultrasonography and computed tomography examination of the abdomen revealed a target sign in the ascending colon, which was compatible with the diagnosis of cecal intussusception. The intussusception was spontaneously resolved at that time, but it relapsed 6 mo later. The patient underwent a successful colonoscopic disinvagination; there was no evidence of neoplastic or inflammatory lesions in the colon and terminal ileum. The patient underwent laparoscopic surgery for recurring cecal intussusception. During laparoscopy, we observed an unfixed cecum on the posterior peritoneum (i.e. a mobile cecum). Thus, we performed laparoscopic appendectomy and cecopexy with a lateral peritoneal flap using a barbed wound suture device. The patient's post-operative course was uneventful, and he continued to do well without recurrence at 10 mo after surgery. Laparoscopic cecopexy using a barbed wound suture device is a simple and reliable procedure that can be the treatment of choice for recurrent cecal intussusception associated with a mobile cecum.

  10. Study on the tribological behavior of surgical suture interacting with a skin substitute by using a penetration friction apparatus. (United States)

    Zhang, Gangqiang; Ren, Tianhui; Zhang, Sheng; Zeng, Xiangqiong; van der Heide, Emile


    Surgical sutures have different sizes, structures, whereas they are being used for various surgeries. The high friction performance of surgical sutures in the suturing process may cause inflammation and pain, leading to a longer recovery time. This paper presents an understanding of the tribological behavior of surgical suture with monofilament and multifilament structures, by means of a penetration friction apparatus (PFA). The results indicated that structure and surface topography of the surgical suture had a pronounced effect on the tribological interactions. It was found that the friction force and abrasion area of skin substitute with the penetration of polyglycolic acid (PGA) multifilament surgical suture were larger than that of Nylon monofilament surgical suture. Meanwhile, more abrasion at the pull-in boundary of skin substitute was observed compared with that at the pull-out boundary. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. [A pancreas suture-less type II binding pancreaticogastrostomy]. (United States)

    Peng, Shu-you; Hong, De-fei; Liu, Ying-bin; Li, Jiang-tao; Tao, Feng; Tan, Zhi-jian


    To explore the feasibility and safety of type II binding pancreaticogastrostomy (BPG) in pancreaticoduodenectomy and mid-segmentectomy of pancreas. From November 2008 to May 2009, 26 patients underwent pancreaticoduodenectomy and mid-segmentectomy of pancreas with type II BPG reconstruction, including 13 cases of pancreatic head cancer, 3 cases of duodenal adenocarcinoma, 2 cases of ampullary carcinoma, 4 cases of cholangiocarcinoma, 1 case of bile duct cell severe atypical hyperplasia, and 1 case of stomach cancer. The process of type II BPG was described as the following: after pancreas remnant was mobilized for 2-3 cm, a piece of sero-muscular layer at the posterior gastric wall was excised and then a sero-muscular depth purse-suturing with 3-0 prolene was pre-placed (outer purse-string). Incising anterior gastric wall or opening part of the closed distal gastric stump, the mucosa layer at the sero-muscular defect was incised and then purse-suture at the mucosal tube was pre-placed (inner purse-string). Through the two pre-placed purse-strings, the pancreas remnant was pulled into the gastric lumen and then posterior gastric wall was pushed backward to keep it closely in contact with the retro-peritoneal wall. Thereafter, the outer purse-string was tied (outer binding) and then the inner purse-string was tied (inner binding). All cases underwent BPG of type II. The operative time ranged from 3 to 5.5 hours. The postoperative hospital stay ranged from 6 to 48 days. Postoperative complications included 1 case of ascites, 2 cases of delayed gastric emptying and 1 case of intra-abdominal bleeding. All cases with complications were cured after nonsurgical treatment. No mortality or pancreatic leakage occurred. Pancreaticogastrostomy is good for accommodating a large pancreas stump. Binding technique is very helpful in minimizing the leak rate of pancreaticogastrostomy. While type I BPG is safe and easy to perform, type II is even safer and easier to be done.

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

    Directory of Open Access Journals (Sweden)

    Adil Bangash


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

  13. Comparison of surgical time and complication rate of subcutaneous and skin closure using barbed suture or traditional knotted suture in dogs. (United States)

    Nutt, Laura K; Wilson, Megan L; Sakals, Sherisse


    This prospective study evaluated the handling, intraoperative and postoperative complication rates of a barbed knotless suture for closure of subcutaneous tissue and skin in 17 client-owned dogs (group A) following a tibial plateau leveling osteotomy procedure. Clinical characteristics, surgical time, and complication rates were compared to a control group of 17 client-owned dogs (group B) with subcutaneous tissue and skin closure using traditional suture material. Signalment was not significantly different between groups and did not have an effect on complication rates. Surgical times were not significantly different for subcutaneous tissue or skin closure between the 2 groups. There were significantly more intraoperative complications in the barbed suture group (A: 4/17; B: 0/17; P = 0.033) but no difference in minor or major postoperative complication rates (minor A: 2/16; B: 1/14; P = 0.626, major A: 2/16; B: 0/14; P = 0.171).

  14. Shape memory alloy fixator system for suturing tissue in minimal access surgery. (United States)

    Xu, W; Frank, T G; Stockham, G; Cuschieri, A


    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.

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

    Directory of Open Access Journals (Sweden)

    Wai-Kwan Wu


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

  16. An automated interrupted suturing device for coronary artery bypass grafting: automated coronary anastomosis. (United States)

    Shennib, H; Korkola, S J; Bousette, N; Giaid, A


    The purpose of this study was to have a preliminary assessment of the safety and efficacy of an automated vascular suturing device. The device (Heartflo, Perclose/Abbott Labs, Redwood City, CA), which delivers 10 interrupted 7-0 polypropylene sutures between side-to-side arteriotomies, was evaluated in animals (8 Yorkshire pigs). Tissue edge capture and quality of anastomosis were highly rated. Time of anastomoses averaged 22 minutes. This time was prolonged primarily due to suture management, tying of interrupted sutures, and learning curve effects. Six of the anastomoses were hemostatic and two required an additional stitch each. Angiography and histology of the anastomosis confirmed patency and quality of the anastomosis. Our preliminary results indicate that the Heartflo automated anastomotic device is safe and effective. Preclinical and clinical studies to validate its acute and long-term effectiveness will commence shortly.

  17. Safety and efficacy of unidirectional barbed suture in mini-laparotomy myomectomy

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    Ming-Chao Huang


    Conclusion: The unidirectional knotless barbed suture may facilitate the repair of uterine defects during mini-laparotomy myomectomy by significantly lowering operative time. It may also reduce the intraoperative blood loss.

  18. Evaluation of Polybutylate-Coated Braided Polyester (Ethibond) Sutures for Levator-Advancement Blepharoptosis Repair (United States)

    Yulish, Michael; Pikkel, Joseph


    Purpose. To evaluate the efficacy and safety of polybutylate-coated braided polyester (Ethibond* 5-0) suture for levator aponeurosis suturing to the anterior tarsal surface in involutional blepharoptosis repair surgery. Methods. Ten consecutive patients (16 eyes) with acquired blepharoptosis which resulted from levator aponeurosis dehiscence with good levator function had gone through surgery and were followed up for, at least, one year. Results. There was no significant change between postoperative MRD1 measurements. No serious complications, such as infection of the sutures, inflammation, granuloma formation or ptosis recurrence, were registered. Conclusion. Polybutylate-coated braided polyester (Ethibond* 5-0) suture is a safe and effective material for involutional blepharoptosis repair surgery. PMID:24558592

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

    LENUS (Irish Health Repository)

    Davis, N F


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

  20. Successful term delivery after Khairy’s modified B-lynch suture technique: First case rep

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    Ahmed M. Abbas


    Full Text Available Postpartum hemorrhage (PPH is a life-threatening obstetric complication. Uterine atony is the most common cause presenting in approximately 80% of cases. As regards management options, B-lynch brace suture, and its modifications have been used for more than a decade with a great success as a substitution for hysterectomy. Their efficiency in preserving future fertility is not well-established. This case reports the first successful pregnancy and delivery after one of the recent B-lynch suture modifications “Khairy’s modification” for control of atonic PPH during cesarean delivery. The patient got pregnant two months after the surgery. The course of pregnancy was smooth and she was delivered by Repeat cesarean section with no deformities of uterine cavity or contour. Khairy’s modified B-lynch suture is an effective technique that has no reported complications of the classic B-lynch suture or affection of subsequent fertility.

  1. Long Short-Term Memory Projection Recurrent Neural Network Architectures for Piano’s Continuous Note Recognition

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    YuKang Jia


    Full Text Available Long Short-Term Memory (LSTM is a kind of Recurrent Neural Networks (RNN relating to time series, which has achieved good performance in speech recogniton and image recognition. Long Short-Term Memory Projection (LSTMP is a variant of LSTM to further optimize speed and performance of LSTM by adding a projection layer. As LSTM and LSTMP have performed well in pattern recognition, in this paper, we combine them with Connectionist Temporal Classification (CTC to study piano’s continuous note recognition for robotics. Based on the Beijing Forestry University music library, we conduct experiments to show recognition rates and numbers of iterations of LSTM with a single layer, LSTMP with a single layer, and Deep LSTM (DLSTM, LSTM with multilayers. As a result, the single layer LSTMP proves performing much better than the single layer LSTM in both time and the recognition rate; that is, LSTMP has fewer parameters and therefore reduces the training time, and, moreover, benefiting from the projection layer, LSTMP has better performance, too. The best recognition rate of LSTMP is 99.8%. As for DLSTM, the recognition rate can reach 100% because of the effectiveness of the deep structure, but compared with the single layer LSTMP, DLSTM needs more training time.

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

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    Manash Ranjan Sahoo


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

  3. Physical and Mechanical Evaluation of Five Suture Materials on Three Knot Configurations: An in Vitro Study

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    Desire Abellán


    Full Text Available The aim of this study was to evaluate and compare the mechanical properties of five suture materials on three knot configurations when subjected to different physical conditions. Five 5-0 (silk, polyamide 6/66, polyglycolic acid, glycolide-e-caprolactone copolymer, polytetrafluoroethylene suture materials were used. Ten samples per group of each material were used. Three knot configurations were compared A.2=1=1 (forward–forward–reverse, B.2=1=1 (forward–reverse–forward, C.1=2=1 (forward–forward–reverse. Mechanical properties (failure load, elongation, knot slippage/breakage were measured using a universal testing machine. Samples were immersed in three different pH concentrations (4,7,9 at room temperature for 7 and 14 days. For the thermal cycle process, sutures were immersed in two water tanks at different temperatures (5 and 55 °C. Elongation and failure load were directly dependent on the suture material. Polyglycolic acid followed by glycolide-e-caprolactone copolymer showed the most knot failure load, while polytetrafluoroethylene showed the lowest (P < 0.001. Physical conditions had no effect on knot failure load (P = 0.494. Statistically significant differences were observed between knot configurations (P = 0.008. Additionally, individual assessment of suture material showed statistically significant results for combinations of particular knot configurations. Physical conditions, such as pH concentration and thermal cycle process, have no influence on suture mechanical properties. However, knot failure load depends on the suture material and knot configuration used. Consequently, specific suturing protocols might be recommended to obtain higher results of knot security.

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


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


    Sutures form an integral part of the functioning skull, but their role has long been debated among vertebrate morphologists and palaeontologists. Furthermore, the relationship between typical skull sutures, and those involved in cranial kinesis, is poorly understood. In a series of computational modelling studies, complex loading conditions obtained through multibody dynamics analysis were imposed on a finite element model of the skull of Uromastyx hardwickii, an akinetic herbivorous lizard. ...

  5. Longitudinal parallel compression suture to control postopartum hemorrhage due to placenta previa and accrete. (United States)

    Li, Guang-Tai; Li, Xiao-Fan; Wu, Baoping; Li, Guangrui


    To assess the efficacy and safety of longitudinal parallel compression suture to control heavy postpartum hemorrhage (PPH) in patients with placenta previa/accreta. Fifteen women received a longitudinal parallel compression suture to stop life-threatening PPH due to placenta previa with or without accreta during cesarean section. The suture apposed the anterior and posterior walls of the lower uterine segment together using an absorbable thread A 70-mm round needle with a Number-1 absorbable thread was used. The point of needle entry was 1 cm above the upper margin of the cervix and 1 cm from the right lateral border of the lower segment of the anterior wall. The suture was threaded through the uterine cavity to the serosa of the posterior wall. Then, it was directed upward and threaded from the posterior to the anterior wall at ∼1-2 cm above the upper boundary of the lower uterine segment and 3-cm medial to the right margin of the uterus. Both ends of the suture were tied on the anterior aspect of uterus. The left side was sutured in the same way. The success rate of the procedure was 86.7% (13/15). Two of 15 cases were concurrently administered gauze packing and achieved satisfactory hemostasis. All patients resumed a normal menstrual flow, and no postoperative anatomical or physiological abnormalities related to the suture were observed. Three women achieved further pregnancies after the procedure. Longitudinal parallel compression suture is a safe, easy, effective, practical, and conservative surgical technique to stop intractable PPH from the lower uterine segment, particularly in women who have a cesarean scar and placenta previa/accreta. Copyright © 2016. Published by Elsevier B.V.

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

    Gauthier-Benoît, C; Prat, A


    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.

  7. Single Incision Distal Biceps Repair With Hemi-Krackow Suture Technique: Surgical Technique and Early Outcomes


    Goljan, Peter; Patel, Nimit; Stull, Justin D.; Donnelly, Brandon P.; Culp, Randall W.


    Background: Many surgical methods exist for distal biceps repair. We present the technique and early outcomes of a series of distal biceps repairs completed with a novel suturing technique utilizing a hemi-Krackow locking stitch at the tendon-bone interface. Methods: A retrospective review was performed of patients who underwent primary distal biceps repair using a single anterior incision with 2 suture anchors utilizing a hemi-Krackow stitch. With both anchors, a locking stitch along the ten...

  8. Clinical inquiries. How does tissue adhesive compare with suturing for superficial lacerations? (United States)

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


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

  9. Morphology of cranial sutures and radiologic evaluation of the variations of intersutural bones. (United States)

    Çalışkan, Selma; Oğuz, Kader Karlı; Tunalı, Selçuk; Aldur, Muhammed Mustafa; Erçakmak, Burcu; Sargon, Mustafa Fevzi


    As far as our literature searches showed us, morphological characteristics of cranium such as sutures, sutural bones and fontanelles had been examined from the skulls in the museums and dry specimens until now. As a modern method, 3D virtual remodeling of cranial bones by using MDCT-CTA can display in vivo morphological characteristics. In our study, we aimed to determine the presence and incidence of these morphological characteristics that can be clinically significant in our population, by using radiologic methods. We examined head and neck regions of 185 patients via MDCT-CTA. We evaluated radiologically detectable variations of the metopic sutures, lambda, bregma, asterion and pterion, which can be very easily confused with fractures. Additionally, the differences between the genders and incidence of coexistence of these variations were evaluated. According to our study, the incidence of persistent metopic suture was 8.1% and the incidence of lambda variations was 5.9%. Variations were most commonly encountered on the left asterion, and least commonly on the bregma and left pterion. In the evaluation of the coexistence of the parameters and combinations; the wormian bones located at the right and left asterions were detected. There were no statistically significant differences between genders. Variations of the sutures and sutural bones can be easily misdiagnosed with the fractures of related bony regions in unconscious patients with multiple traumas. During surgical interventions in these type of patients; surgeons must take this fact into consideration in order to make differential diagnosis of fractures and intersutural bone variations.

  10. Closure of round cutaneous defects progressively with the purse string suture technique. (United States)

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


    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. 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. 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. 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.

  11. Instructional PowerPoint presentations for cutaneous wound healing and tissue response to sutures. (United States)

    Stroncek, John D; Bell, Nicole; Reichert, W Monty


    Wound healing is an intricate process involving the interaction of cells and molecules, resulting in a complex series of events that change the morphology and characteristics of the wounded area. Interactive animations are useful for illustrating challenging concepts, helping students learn and retain new material. Instructional PowerPoint presentations describing the basic elements of cutaneous wound healing and the response of cutaneous tissue to sutures were developed by seven biomedical engineering students at Duke University. "Cutaneous Wound Healing.ppt" is an interactive presentation reviewing the four phases of wound healing (hemostasis, inflammation, repair, and remodeling) as well as the major molecular and cellular mechanisms that comprise these processes for cutaneous tissue. "Tissue Response to Sutures.ppt" is an interactive presentation that uses sutures to illustrate the foreign body response to biomaterials in cutaneous tissue. The tissue response program reviews the basics of suturing, common suture materials, and the tissue, cellular, and molecular responses to absorbable and nonabsorbable sutures. This manuscript provides a brief overview of the programs that are freely available on the Duke Center for Biomolecular and Tissue Engineering web site at Copyright 2008 Wiley Periodicals, Inc.

  12. Augmentation of tendon healing with butyric acid-impregnated sutures: biomechanical evaluation in a rabbit model. (United States)

    Leek, Bryan T; Tasto, James P; Tibor, Lisa M; Healey, Robert M; Freemont, Anthony; Linn, Michael S; Chase, Derek E; Amiel, David


    Butyric acid (BA) has been shown to be angiogenic and to enhance transcriptional activity in tissue. These properties of BA have the potential to augment biological healing of a repaired tendon. To evaluate this possibility both biomechanically and histologically in an animal tendon repair model. Controlled laboratory study. A rabbit Achilles tendon healing model was used to evaluate the biomechanical strength and histological properties at 6 and 12 weeks after repair. Unilateral tendon defects were created in the middle bundle of the Achilles tendon of each rabbit, which were repaired equivalently with either Ultrabraid BA-impregnated sutures or control Ultrabraid sutures. After 6 weeks, BA-impregnated suture repairs had a significantly increased (P Tendons repaired with BA-impregnated sutures demonstrated improved biomechanical properties at 6 weeks relative to control sutures, suggesting a neoangiogenic mechanism of enhanced healing through an increased myofibroblast presence. These findings demonstrate that a relatively simple alteration of suture material may augment early tendon healing to create a stronger repair construct during this time.

  13. Tarsal platform show after upper eyelid blepharoplasty with or without brassiere sutures

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    Marisa Novaes de Figueiredo

    Full Text Available ABSTRACT Purpose: Increased tarsal platform show (TPS and decreased brow fat span (BFS are associated with favorable results in women undergoing cosmetic blepharoplasty. We conducted a study to evaluate the efficacy of upper blepharoplasty with or without a technique (brassiere sutures to increase TPS and decrease BFS. Methods: This is a prospective, randomized, comparative, case series study of 100 eyelids (50 consecutive women patients treated with cosmetic upper blepharoplasty performed by a single surgeon. Patients were randomized to receive traditional upper blepharoplasty with a single running suture skin closure versus orbicularis oculi muscle fixation to the periosteum (brassiere sutures prior to skin closure. Data on patient age, duration of follow-up, complications, and treatment were analyzed. The mean TPS, mean BFS, and mean TPS/BFS ratio were measured at three anatomic landmarks before and after surgery. Results: Fifty-six eyelids (28 patients were treated with traditional single suture blepharoplasty, and 44 eyelids (22 patients had brassiere sutures. In both groups, paired t-tests indicate significant differences between preoperative and postoperative evaluations (p0.05. Conclusions: Brassiere sutures during upper blepharoplasty and traditional blepharoplasty were associated with postoperative increase in TPS, decrease in BFS, and increase in TPS/BFS, without statistically significant differences between these surgeries.

  14. Cranial Suture Closure in Domestic Dog Breeds and Its Relationships to Skull Morphology. (United States)

    Geiger, Madeleine; Haussman, Sinah


    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. © 2016 Wiley Periodicals, Inc.

  15. Bile duct stone formation around a nylon suture after gastrectomy: a case report. (United States)

    Maeda, Chiyo; Yokoyama, Naoyuki; Otani, Tetsuya; Katada, Tomohiro; Sudo, Natsuru; Ikeno, Yoshinobu; Matsuura, Fumiaki; Iwaya, Akira; Yamazaki, Toshiyuki; Kuwabara, Shirou; Katayanagi, Norio


    Many cases of choledocholiths formed around sutures and clips used during cholecystectomy have been reported. We describe a case of gallstone formation around a nylon suture after non-biliary surgery. To the best of our knowledge, this is the first report of such a case. A 75-year-old Japanese man, who had undergone distal gastrectomy for gastric cancer and reconstruction with the Billroth II method 8 years earlier, presented with gastric discomfort. Abdominal ultrasonography was conducted and we diagnosed cholecysto-choledocholithiasis with dilatation of the intrahepatic bile duct. He underwent cholecystectomy and cholangioduodenostomy for choledocholith removal. Gallstones, which had formed around a nylon suture used during the previous gastrectomy, were found in the bile duct. Sutures of the same material had also been placed on the duodenum. Chemical analysis revealed that the stones were composed of calcium bilirubinate. The patient was discharged on postoperative day 19, and choledocholithiasis has not recurred thus far. The findings from this case suggest that standard, non-resorbable sutures used in gastrectomy may be associated with the formation of bile duct stones; therefore, absorbable suture material may be required to avert gallstone formation even in the case of gastrectomy.

  16. Symbol "&" suture to control atonic postpartum hemorrhage with placenta previa accreta. (United States)

    Li, Guang Tai; Li, Xiao Fan; Liu, Ya Jing; Li, Wei; Xu, Hong Mei


    To evaluate the efficacy and safety of a symbol "&" compression suture technique in controlling severe atonic postpartum hemorrhage with placenta previa accreta during cesarean delivery. Nine women with heavy postpartum bleeding from uterine inertia and placenta previa percret, which did not react to conventional initial management protocols, were underwent the suture in the shape of symbol "&" in China Meitan General Hospital. The suture procedure was to staple the anterior and posterior walls (of the lower uterine segment as well as corpus uterus) together using number 1 chromic catgut, with a cross at about 2 cm above the upper boundary of lower uterine segment. Symbol "&" compression suture was capable of stanching the postpartum hemorrhage immediately in all nine women. None of these patients developed complications related to this method. Subsequent pregnancies after the suture were occurred in two women and delivered with repeat cesarean section. Symbol "&" compression suture is a simple, safe and highly effective technique to control the treatment-resistant uterine atonic bleeding, particularly in previous cesarean scar at lower segment and placenta previa accreta.

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

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    Gazivoda Dragan


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

  18. Bio-inspired ``jigsaw''-like interlocking sutures: Modeling, optimization, 3D printing and testing (United States)

    Malik, I. A.; Mirkhalaf, M.; Barthelat, F.


    Structural biological materials such as bone, teeth or mollusk shells draw their remarkable performance from a sophisticated interplay of architectures and weak interfaces. Pushed to the extreme, this concept leads to sutured materials, which contain thin lines with complex geometries. Sutured materials are prominent in nature, and have recently served as bioinspiration for toughened ceramics and glasses. Sutures can generate large deformations, toughness and damping in otherwise all brittle systems and materials. In this study we examine the design and optimization of sutures with a jigsaw puzzle-like geometry, focusing on the non-linear traction behavior generated by the frictional pullout of the jigsaw tabs. We present analytical models which accurately predict the entire pullout response. Pullout strength and energy absorption increase with higher interlocking angles and for higher coefficients of friction, but the associated high stresses in the solid may fracture the tabs. Systematic optimization reveals a counter-intuitive result: the best pullout performance is achieved with interfaces with low coefficient of friction and high interlocking angle. We finally use 3D printing and mechanical testing to verify the accuracy of the models and of the optimization. The models and guidelines we present here can be extended to other types of geometries and sutured materials subjected to other loading/boundary conditions. The nonlinear responses of sutures are particularly attractive to augment the properties and functionalities of inherently brittle materials such as ceramics and glasses.

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

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    Alida M Bailleul

    Full Text Available 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.



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


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

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

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    Gazivoda Dragan


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

  2. A new method for sex estimation from maxillary suture length in a Thai population (United States)

    Sinthubua, Apichat; Ruengdit, Sittiporn; Das, Srijit


    Sex estimation is one of the crucial procedures in the biological profile identification of human skeletal remains. Knowing sex of unknown case can lead to accurate and appropriate methods for predicting age, stature, ancestry, or even personal identification. Skull is one of the most reliable one among other skeletons and it is usually retained for both archaeological and forensic contexts. Although many morphological features and metric measurements of skull have been studied for sexing, but to the best of our knowledge is no study on maxillary suture length for sex estimation. Therefore, this study aims to develop a new sex estimation method for a Thai population by determining three maxillary suture lengths: anterior, transverse, and posterior maxillary suture, by computerizing amount of pixel obtained from photographs of these sutures. The present study was conducted on 190 Thai bone samples of which 96 were males and 94 were females. Independent t test revealed statistically significant difference (P<0.01) between males and females in all maxillary suture measurements. Equations derived from prediction model, which required three maxillary suture lengths gave 76.8421% accuracy from the leave-one-out cross validation in estimating sex percentage accuracies in predicting sex from these equations, which were relatively moderate. This study provides a novel and objective sex estimation method for Thais. It suggests that maxillary suture length can be applied for sex estimation. The new computerized technique will contribute basis knowledge and method for sex estimation, especially when only base of skull is available in forensic circumstance. PMID:29354297

  3. Comparison of efficacy of polypropylene with chromic catgut suture in stitching paediatric facial lacerations

    International Nuclear Information System (INIS)

    Hussain, A.; Ahmed, R.; Aziz, O.B.A.; Aamir, M.


    Objective: The objective of this study was to compare 5/0 polypropylene suture with 5/0 chromic catgut in small clean pediatric facial laceration repair in terms of cosmetic outcome. Study Design: Randomized controlled trial.Place and Duration of Study: Combined Military Hospital, Rawalpindi from 26th May 2012 to 25th Nov 2012.Patients and Methods: A total of 300 patients of both gender under 12 years of age, with small clean facial lacerations were selected and divided in two equal groups using random number tables. All the patients underwent suturing in minor operating theater of trauma centre CMH Rawalpindi as day care cases, under local anesthesia and aseptic measures. In group 1, polypropylene 5/0 suture was used where as in group 2 chromic catgut 5/0 was used for suturing. Aseptic dressing was applied. All patients were reviewed on 5th day (for stitch removal in polypropylene group) and 3 months post-operatively to establish cosmetic outcome which was determined by scar visual analog score both by parents of the child and consultant surgeon. Results: The mean VAS (visual analog score) as observed by Consultant surgeon was 79.14 and 78.63 for polypropylene and chromic catgut groups respectively. The mean VAS observed by the parents of the child for respective groups was 76.67 and 76.03. The significance value was 0.961 for parental VAS and 0.988 for surgeons VAS depicting insignificant difference in both suture groups.Conclusion: There is no long-term difference in cosmetic outcomes of both the sutures in the repair of facial lacerations in the pediatric population. No difference in complication rate of wound was observed. In addition, the parents of the children in absorbable suture group expressed satisfaction over prevention of psychological trauma of stitch removal. (author)

  4. Randomized clinical trial comparing cold knife conization of the cervix with and without lateral hemostatic sutures. (United States)

    Bueno, Letícia Rossi; Binda, Marcia; Monego, Heleusa; Scherer, Roberta Luísa; Rolim, Karen Machado; Bottini, Alessandra Leal; Fregnani, José H T G; dos Reis, Ricardo


    Compare blood loss during cold knife conization of the cervix with and without lateral hemostatic sutures in the cervical branches of the uterine arteries. Randomized clinical trial. Hospital de Clínicas de Porto Alegre (HCPA). 102 patients that underwent cold knife conization. Women that underwent cold knife conization of the cervix were randomized to undergo the procedure with or without lateral hemostatic sutures. blood loss measured in grams. operative time and postoperative intervention. Only the participants were blinded to group assignment. From March 2009 to August 2012, patients were randomly assigned to one of the study groups. There were no differences in amount of blood loss between patients that underwent the procedure with and without sutures (p = 0.39). Operative time was shorter in the group without suture (p = 0.020). There were no differences in intervention due to bleeding (p = 0.20). Blood loss was greater among menstruating women than for menopausal women (p = 0.011). There were no differences in amount of blood lost between smoking and nonsmoking patients (p = 0.082). Lateral hemostatic sutures do not affect the amount of intraoperative bleeding or the number of postoperative interventions. Their use is not necessary because they result in longer operative time, have a higher cost due to the use of suture material and pose the risk of ureter lesion in case the sutures are not placed at a lower position in the cervix. ClinicalTrials. gov identifier: NCT02184975. Copyright © 2015 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

  5. Continuous auditing & continuous monitoring : Continuous value?

    NARCIS (Netherlands)

    van Hillo, Rutger; Weigand, Hans; Espana, S; Ralyte, J; Souveyet, C


    Advancements in information technology, new laws and regulations and rapidly changing business conditions have led to a need for more timely and ongoing assurance with effectively working controls. Continuous Auditing (CA) and Continuous Monitoring (CM) technologies have made this possible by

  6. Scalp swelling crossing the suture line on skull radiograph: is it always a sign of caput succedaneum?

    International Nuclear Information System (INIS)

    Choi, Jae Woong; Lee, Chang Hee; Suh, Sang Il


    Caput succedaneum is the soft swelling of the neonatal scalp that may extend over the suture line, as opposed to cephalhaematoma, which is restricted by the suture. However, if caput succedaneum and cephalhaematoma coexist and the swelling crosses the suture line, it may be diagnosed as caput succedaneum and the cephalhaematoma will be easily missed, both on the radiograph and clinically. We report an interesting MR finding in a neonate who simultaneously showed both caput succedaneum and cephalhaematoma. (orig.)

  7. The efficacy of laparoscopic intracorporeal linear suture technique as a strategy for reducing recurrences in pediatric inguinal hernia. (United States)

    Lee, S R; Choi, S B


    Pediatric laparoscopic herniorrhaphy has rare complications, but recurrence might occur. The purpose of this manuscript is to evaluate the efficacy of linear suture technique of laparoscopic pediatric herniorrhaphy in reducing recurrences. Laparoscopic surgery was performed on 2223 pediatric patients (under 10 years old) from September 2012 to December 2014 in Damsoyu Hospital, Seoul, Republic of Korea. The causes of recurrence were investigated case by case. The patients were categorized into two groups according to the suture method used in closing the hernia orifice: Group 1 (purse-string suture, 1009 patients) and Group 2 (linear suture, 1214 patients). There were 1413 (63.6%) male and 810 (36.4%) female patients. Mean age was 30.5 ± 29.2 months. A significantly higher proportion of male patients, contralateral patent processus vaginalis, and less proportion of recurrence were observed in Group 2. There were ten cases of recurrence in Group 1 because the internal ring suture could not endure the tension. One recurrence occurred in Group 2. The suture technique and age were found to be a significant risk factor for recurrence. Linear suture technique had a lower recurrence rate (odds ratio = 0.07, with 95% confidence interval 0.01-0.53, and p = 0.004). Purse-string suture technique causes significantly higher occurrence of hernia recurrences than linear suture technique. Linear suture technique can reduce recurrence by increasing the endurance to tension around the internal ring by distributing pressure to a wider area along the linear suture line. Linear suture technique can effectively reduce recurrence in pediatric inguinal herniorrhaphy.

  8. Gastric full-thickness suturing during EMR and for treatment of gastric-wall defects (with video). (United States)

    von Renteln, Daniel; Schmidt, Arthur; Riecken, Bettina; Caca, Karel


    The endoscopic full-thickness Plicator device was initially developed to provide an endoscopic treatment option for patients with GERD. Because the endoscopic full-thickness Plicator enables rapid and easy placement of transmural sutures, comparable with surgical sutures, we used the Plicator device for endoscopic treatment or prevention of GI-wall defects. To describe the outcomes and complications of endoscopic full-thickness suturing during EMR and for the treatment of gastric-wall defects. A report of 4 cases treated with the endoscopic full-thickness suturing between June 2006 and April 2007. A large tertiary-referral center. Four subjects received endoscopic full-thickness suturing. The subjects were women, with a mean age of 67 years. Of the 4 subjects, 3 received endoscopic full-thickness suturing during or after an EMR. One subject received endoscopic full-thickness suturing for treatment of a fistula. Primary outcome measurements were clinical procedural success and procedure-related adverse events. The mean time for endoscopic full-thickness suturing was 15 minutes. In all cases, GI-wall patency was restored or ensured, and no procedure-related complications occurred. All subjects responded well to endoscopic full-thickness suturing. The resection of one GI stromal tumor was incomplete. Because of the Plicator's 60F distal-end diameter, endoscopic full-thickness suturing could only be performed with the patient under midazolam and propofol sedation. The durable Plicator suture might compromise the endoscopic follow-up after EMR. The endoscopic full-thickness Plicator permits rapid and easy placement of transmural sutures and seems to be a safe and effective alternative to surgical intervention to restore GI-wall defects or to ensure GI-wall patency during EMR procedures.

  9. Evaluation of the histologic reactions to commonly used suture materials in the skin and musculature of ball pythons (Python regius). (United States)

    McFadden, Michael S; Bennett, R Avery; Kinsel, Michael J; Mitchell, Mark A


    To evaluate histologic reactions to 8 suture materials and cyanoacrylate tissue adhesive (CTA) in the musculature and skin of ball pythons. 30 hatchling ball pythons. In each snake, ten 1-cm skin incisions were made (day 0). At 8 sites, a suture of 1 of 8 materials was placed in the epaxial musculature, and the incision was closed with the same material. One incision was closed by use of CTA. No suture material was placed in the tenth incision, which was allowed to heal by second intention (negative control). Snakes (n = 5/group) were euthanized for harvest of treatment-site tissues at days 3, 7, 14, 30, 60, and 90. Skin and muscle sections were examined microscopically and assigned a subjective score (0 to 4) for each of the following: overall severity of inflammation, fibrosis, number of macrophages, number of granulocytes, number of perivascular lymphocytes, and degree of suture fragmentation. Subjective score analysis revealed that CTA did not cause a significant inflammatory response, compared with the negative control. All suture materials caused significantly more inflammation over all time points; for all suture materials, inflammatory response scores were significantly higher than values for the negative control 90 days after implantation. No sutures were completely absorbed by the end of the study period, and several sutures appeared to be in the process of extrusion. In snakes, CTA can be used to close small superficial incisions or lacerations with minimal inflammatory response, and sutures may undergo extrusion from tissues prior to complete absorption.

  10. High-Tensile Strength Tape Versus High-Tensile Strength Suture: A Biomechanical Study. (United States)

    Gnandt, Ryan J; Smith, Jennifer L; Nguyen-Ta, Kim; McDonald, Lucas; LeClere, Lance E


    To determine which suture design, high-tensile strength tape or high-tensile strength suture, performed better at securing human tissue across 4 selected suture techniques commonly used in tendinous repair, by comparing the total load at failure measured during a fixed-rate longitudinal single load to failure using a biomechanical testing machine. Matched sets of tendon specimens with bony attachments were dissected from 15 human cadaveric lower extremities in a manner allowing for direct comparison testing. With the use of selected techniques (simple Mason-Allen in the patellar tendon specimens, whip stitch in the quadriceps tendon specimens, and Krackow stitch in the Achilles tendon specimens), 1 sample of each set was sutured with a 2-mm braided, nonabsorbable, high-tensile strength tape and the other with a No. 2 braided, nonabsorbable, high-tensile strength suture. A total of 120 specimens were tested. Each model was loaded to failure at a fixed longitudinal traction rate of 100 mm/min. The maximum load and failure method were recorded. In the whip stitch and the Krackow-stitch models, the high-tensile strength tape had a significantly greater mean load at failure with a difference of 181 N (P = .001) and 94 N (P = .015) respectively. No significant difference was found in the Mason-Allen and simple stitch models. Pull-through remained the most common method of failure at an overall rate of 56.7% (suture = 55%; tape = 58.3%). In biomechanical testing during a single load to failure, high-tensile strength tape performs more favorably than high-tensile strength suture, with a greater mean load to failure, in both the whip- and Krackow-stitch models. Although suture pull-through remains the most common method of failure, high-tensile strength tape requires a significantly greater load to pull-through in a whip-stitch and Krakow-stitch model. The biomechanical data obtained in the current study indicates that high-tensile strength tape may provide better repair

  11. Long-term efficacy of anchored barbed sutures in the face and neck. (United States)

    Kaminer, Michael S; Bogart, Megan; Choi, Christine; Wee, Sue Ann


    The thread lift is a minimally invasive procedure that uses barbed sutures, inserted subcutaneously, to produce lifting of ptotic tissue of the face and neck. There are currently very limited data on longevity and patient satisfaction following barbed suture lifting procedures. The purpose of this study was to assess long-term efficacy following the use of barbed sutures. A satisfaction survey was mailed to 20 patients who were a minimum of 6 months (range, 6 to 16 months) postprocedure. Physician assessment of pre- and postprocedure photographs was also performed. At an average of 11.5 months postprocedure, patients felt that the barbed suture lift met their expectations, rating their satisfaction a 6.9 on a scale of 1 to 10. Independent physicians rated the overall improvement an average of 4.6 of 10. Higher scores were noted in Zone 1 (tear trough/malar fat pad and nasolabial folds) compared to Zone 2 (marionette lines, jowls, and jawline definition) and Zone 3 (platysmal bands and neck contour). The barbed suture lift procedure provides moderate long-term and sustained improvement for facial laxity, with most improvement seen in the tear trough/malar fat pads and nasolabial folds. In this study, clinical efficacy was seen up to 16 months postprocedure.

  12. Sutured clear corneal incision: wound apposition and permeability to bacterial-sized particles. (United States)

    May, William N; Castro-Combs, Juan; Kashiwabuchi, Renata T; Tattiyakul, Woranart; Qureshi-Said, Saima; Hirai, Flavio; Behrens, Ashley


    To determine the effects of single radial or horizontal suture placement in 2-step clear corneal incision (CCI) wound apposition and permeability to particles of India ink. Five fresh human globes were included. Two 25-gauge needles connected to a saline solution bag and to a digital manometer were inserted through the limbus, 120 degrees apart from each other. Four 2-step CCIs (2.75 mm wide and 3 mm length) were constructed in each cornea. Incisions were divided into 3 groups: single radial suture (SRS), single horizontal suture (SHS), and unsutured group. Optical coherence tomography (OCT) was performed before and after suture placement. With a preset 10 mm Hg intraocular pressure (IOP), India ink was applied to the incision site and a standardized sudden IOP fluctuation was induced. OCT and superficial images were recorded before and after suture placement. India ink inflow and internal and external CCI gapping were outlined and measured by planimeter. The area and linear distance of India ink inflow after pressure challenge in all study groups were higher when compared with pre-pressure measurements; however, this increase was significant in the SRS and SHS groups (P < 0.05). Additionally, SRS placement significantly increased inner wound gapping (P = 0.018), and SHS significantly widened outer wound gape (P = 0.02). Well-constructed unsutured 2-step CCI seems to be more efficient at preventing bacterial-sized particles inflow during sudden changes in IOP, and it seems to offer better wound apposition as assessed by OCT.

  13. The unidirectional barbed suture for renorrhaphy during laparoscopic partial nephrectomy: Stanford experience. (United States)

    Jeon, Seung Hyun; Jung, Saebin; Son, Hee-Seo; Kimm, Simon Y; Chung, Benjamin I


    Using barbed suture represents a novel technical modification in the performance of minimally invasive partial nephrectomy. Our purpose of this study was to evaluate the safety and efficacy of this suture for renorrhaphy during laparoscopic partial nephrectomy (LPN). Thirteen consecutive patients underwent LPN using V-Loc™ 180 (Covidien, Dublin, Ireland) suture, and a nonconsecutive control group of 24 patients, matched according to tumor size and R.E.N.A.L. nephrometry score, underwent LPN using absorbable polyglactin suture. All 37 patients underwent LPN performed by a single surgeon. Perioperative and postoperative indicators of morbidity, estimated blood loss, and warm ischemia time (WIT) were compared between the groups. Baseline characteristics including age, body mass index, American Society of Anesthesiologists score, tumor size, laterality, and R.E.N.A.L nephrometry score were identical between the groups. On multivariable analysis, there were no significant differences between the two groups with regard to operative time, estimated blood loss, transfusion rates, rates of surgical complications, and length of hospital stay. However, mean WIT was significantly shorter in the V-Loc group compared with the control group (24.5±5.3 minutes versus 31.9±8.9 minutes, P=.01). The use of V-Loc sutures for renorrhaphy during LPN is safe and feasible and, in our series, significantly reduces WIT. Further studies are needed to corroborate these findings, but these results indicate a promising development in reducing WIT during minimally invasive partial nephrectomy.

  14. The Gore-Tex Suture in Periareolar Closure: A Modified Closure Technique. (United States)

    Chapman, Jade; Ingram, Scott


    In breast reduction and mastopexy procedures, the periareolar closure forms a vital component of the surgery. Periareolar closures completed with an absorbable suture may be prone to significant widening, hypertrophy and/or areolar distortion. In an effort to avoid this, some surgeons use a non-absorbable/permanent suture material [Franco (Arch Plast Surg 41 (6): 728-733, 2014)]. Hammond (Plast Reconstr Surg 119 (3):804-809, 2007) recommends the use of a Gore-Tex® suture for this purpose in view of the supple, pliable nature of the material; however, there remain at least occasional instances of infection and extrusion of the knot used to tie off the Gore-Tex "purse-string" [Franco (Arch Plast Surg 41 (6): 728-733, 2014); Salgarello (Aesthet Plast Surg 37 (5):1061-1062, 2013)]. We describe a method of securing the suture ends, which avoids the creation of a bulky knot, thus minimising the risk of infection and suture extrusion. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors .